JP2012198282A - λ/4 PLATE, MANUFACTURING METHOD THEREOF, POLARIZING PLATE, LIQUID CRYSTAL DISPLAY DEVICE, AND STEREOSCOPIC IMAGE DISPLAY DEVICE - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a λ/4 plate which is excellent in surface processing suitability and polarizer durability and has excellent optical characteristics such as retardation property and reverse wavelength dispersibility and a manufacturing method thereof, and to provide a polarizing plate, a liquid crystal display device, and a stereoscopic image display device having the λ/4 plate.SOLUTION: A λ/4 plate contains a compound represented by a specific general formula and a cellulose ester resin. The λ/4 plate is extended in a direction crossing the longitudinal direction and its in-plane retardation Ro (550), measured with a measurement wavelength 550 nm under the temperature 23°C and the relative humidity 55%RH, falls within the range of 100-160 nm and its orientation angle θ falls within the range of 40-50°.

Description

  The present invention relates to a ¼λ plate and a manufacturing method thereof. The present invention also relates to a polarizing plate, a liquid crystal display device, and a stereoscopic image display device provided with the λ / 4 plate.

  In recent years, stereoscopic image display devices such as televisions capable of displaying stereoscopic (3D) images have been proposed. As one of the methods for displaying the stereoscopic image, there is a method for allowing the observer to recognize the two-dimensional image as a stereoscopic image by wearing dedicated stereoscopic image viewing glasses by the observer. What is currently viewed as promising in this method is that the right-eye image and the left-eye image, which are parallax images, are alternately displayed in time series on the display that displays the image, and the observer uses glasses for viewing stereoscopic images. This is a method in which an image of a display is viewed while wearing (see, for example, Patent Document 1).

  The stereoscopic image display device including the display and the glasses for visually recognizing stereoscopic images has problems such as crosstalk (a phenomenon that appears double), a decrease in luminance, and a change in color when the head is tilted. In order to prevent the occurrence of such a problem when the head is tilted, it is effective to use λ / 4 plates on the surface on the viewing side of the liquid crystal display and the surface on the side far from the eyes of the stereoscopic image viewing glasses. .

  On the other hand, the λ / 4 plate has many uses such as an optical compensation film for a liquid crystal display device and an antireflection film for an organic EL display. In order to give various functions to the four plates to achieve high performance or high performance, a surface processed layer is provided, or the surface is directly processed. As such λ / 4 plates, λ / 4 plates containing various compounds have been proposed (see, for example, Patent Documents 2 and 3).

  However, the conventionally known λ / 4 plate has a problem that the adhesion and hardness between the λ / 4 plate and the surface processed layer are deteriorated by humidity, heat, light, and the like. Further, when such a λ / 4 plate is used for a polarizing plate, there is a problem that the polarizer is also deteriorated.

Japanese Patent Laid-Open No. 8-201942 JP 2003-262721 A JP 2009-48204 A

  The present invention has been made in view of the above-mentioned problems and situations, and the problem to be solved is λ excellent in surface processing suitability and polarizer durability, and excellent in optical properties such as retardation and reverse wavelength dispersion. / 4 plate and its manufacturing method. Another object of the present invention is to provide a polarizing plate, a liquid crystal display device, and a stereoscopic image display device provided with the λ / 4 plate.

  The above-mentioned problem according to the present invention is solved by the following means.

1. A λ / 4 plate containing a compound represented by the following general formula (PEI) and a cellulose ester resin, which is stretched in a direction oblique to the longitudinal direction, and has a temperature of 23 ° C. and a relative humidity of 55% RH. The λ / 4 plate is characterized in that the in-plane retardation Ro (550) measured at a measurement wavelength of 550 nm is in the range of 100 to 160 nm and the orientation angle θ is in the range of 40 to 50 °.
Formula (PEI): B- (GA) _n -GB
(B represents a benzene monocarboxylic acid residue. G represents an alkylene glycol residue having 2 to 12 carbon atoms, an aryl glycol residue having 6 to 12 carbon atoms, or an oxyalkylene glycol residue having 4 to 12 carbon atoms. And A represents an alkylene dicarboxylic acid residue having 4 to 12 carbon atoms or an aryl dicarboxylic acid residue having 6 to 12 carbon atoms, and n represents an integer of 0 or more.)
2. the log P value is 6.0 or less and the SP value in the Fedors method is in the range of 8.0 to 12.0, or the log P value is in the range of 6.1 to 12.0, And a λ / 4 plate containing a compound having an SP value in the range of 8.0 to 10.0 by the Fedors method and a cellulose ester resin, and is stretched in a direction oblique to the longitudinal direction. In-plane retardation Ro (550) measured at a measurement wavelength of 550 nm at a temperature of 23 ° C. and a relative humidity of 55% RH is in the range of 100 to 160 nm, and the orientation angle θ is in the range of 40 to 50 °. A λ / 4 plate characterized by the above.

  3. The λ / 4 plate according to item 1 or 2, which contains a compound having a 1,3,5-triazine ring.

4). The first to second items, wherein X and Y satisfy the following formulas (1) and (2), where X is an acetyl group substitution degree and Y is a propionyl group substitution degree of the cellulose ester resin: The λ / 4 plate according to any one of items 3 to 3.
Formula (1): 2.0 ≦ (X + Y) ≦ 2.8
Formula (2): 0 ≦ Y ≦ 1.0
5. The cellulose ester resin in which the cellulose ester resin satisfying the formula (1) and the formula (2) contains a cellulose ester resin satisfying the following formula (1a) and the formula (2) and a cellulose ester resin satisfying the following formula (1b). The λ / 4 plate according to item 4, which is a resin.
Formula (1a): 2.0 ≦ (X + Y) <2.5
Formula (1b): 2.5 ≦ (X + Y) ≦ 2.8
6). The λ / 4 plate according to any one of items 1 to 5, wherein the transmittance of light having a wavelength of 380 nm is 10% or less.

  7). The λ / 4 plate according to any one of items 1 to 6, which has a clear hard coat layer or an antiglare hard coat layer on a surface thereof.

  8). The λ / 4 plate according to item 7, wherein the antiglare hard coat layer does not contain fine particles.

  9. A method for producing a λ / 4 plate according to any one of items 1 to 8, wherein the original film is first stretched in the width direction and then stretched. And a method of manufacturing a λ / 4 plate, comprising a step of curving the conveying direction while contracting in a vertical direction.

  10. A polarizing plate comprising the λ / 4 plate according to any one of items 1 to 8 above.

  11. A liquid crystal display device comprising the λ / 4 plate according to any one of items 1 to 8.

  12 A stereoscopic image display apparatus comprising the λ / 4 plate according to any one of the first to eighth aspects.

  By the above means of the present invention, it is possible to provide a λ / 4 plate excellent in surface processing suitability and polarizer durability, and excellent in optical properties such as phase difference and reverse wavelength dispersion, and a method for producing the same. In addition, a polarizing plate, a liquid crystal display device, and a stereoscopic image display device provided with the λ / 4 plate can be provided.

Schematic diagram of obliquely stretched tenter according to the present invention Schematic showing the track (rail pattern) of the rail of the tenter used in the manufacturing method of the present invention Schematic diagram of the stretching equipment used in the examples Schematic diagram of the stretching equipment used in the examples Schematic diagram of a 3D image display device (system with one polarizing plate for glasses) Schematic diagram of liquid 3D image display device (system with two polarizing plates for glasses)

  The λ / 4 plate of the present invention has a compound represented by the general formula (PEI) or a log P value of 6.0 or less and a SP value in the Fedors method of 8.0 to 12.0. A compound having a log P value in the range of 6.1 to 12.0, and an SP value in the range of Fedors method in the range of 8.0 to 10.0, and a cellulose ester resin, In-plane retardation Ro (550) measured at a measurement wavelength of 550 nm at a temperature of 23 ° C. and a relative humidity of 55% RH. ) Is in the range of 100 to 160 nm, and the orientation angle θ is in the range of 40 to 50 °. This feature is a technical feature common to the inventions according to claims 1 to 12.

  As an embodiment of the present invention, it is preferable that a compound having a 1,3,5-triazine ring is contained from the viewpoint of the effect of the present invention.

  In the present invention, when the cellulose ester resin has an acetyl group substitution degree of X and a propionyl group substitution degree of Y, X and Y preferably satisfy the above formulas (1) and (2). Moreover, the cellulose ester resin satisfying the formula (1) and the formula (2) contains the cellulose ester resin satisfying the formula (1a) and the formula (2) and the cellulose ester resin satisfying the formula (1b). A cellulose ester resin is preferred.

  In the present invention, the transmittance of light having a wavelength of 380 nm is preferably 10% or less. Further, it is preferable to have a clear hard coat layer or an antiglare hard coat layer on the surface of the λ / 4 plate of the present invention. In this case, it is preferable that the antiglare hard coat layer does not contain fine particles.

  The production method of the λ / 4 plate of the present invention is a production method of an embodiment having a step of curving the conveyance direction while first contracting the raw film in the width direction and then contracting in the direction perpendicular to the stretching axis. Is preferred.

  The λ / 4 plate of the present invention can be suitably included in a polarizing plate. Therefore, it can be used for a liquid crystal display device. In particular, the liquid crystal display device can be used for a stereoscopic image display device.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, in this application, "-" is used in the meaning which includes the numerical value described before and behind that as a lower limit and an upper limit.

(Outline of λ / 4 plate of the present invention)
The λ / 4 plate of the present invention is stretched in a direction oblique to the longitudinal direction, and has an in-plane retardation Ro (550) of 100 measured at a measurement wavelength of 550 nm at a temperature of 23 ° C. and a relative humidity of 55% RH. It is in the range of ˜160 nm, and the orientation angle θ is in the range of 40 to 50 °.

  “Λ / 4 plate” means a plate having a function of converting linearly polarized light having a specific wavelength into circularly polarized light (or circularly polarized light into linearly polarized light). The λ / 4 plate is designed such that the in-plane retardation value Ro is about 1/4 with respect to a predetermined wavelength of light (usually in the visible light region). At a temperature of 23 ° C. and a relative humidity of 55% RH, the retardation value Ro (550) measured at a wavelength of 550 nm is required to be in the range of 100 to 160 nm, and preferably 110 to 150 nm.

  Further, the λ / 4 plate is preferably a retardation plate having a retardation of approximately ¼ of the wavelength in the visible light wavelength range in order to obtain almost perfect circularly polarized light in the visible light wavelength range. .

  The term “retardation of approximately ¼ in the wavelength range of visible light” means a retardation value represented by the following formula (i) measured at a wavelength of 450 nm, with a larger retardation at a wavelength of 400 to 700 nm. It is preferable that Ro (590) which is a retardation value measured at a certain Ro (450) and a wavelength of 590 nm satisfies 1 <Ro (590) / Ro (450) ≦ 1.6. Furthermore, in order to function effectively as a λ / 4 plate, Ro (450) is in the range of 90 to 125 nm, and the retardation value Ro (550) measured at a wavelength of 550 nm is in the range of 115 to 142 nm. , Ro (590) is more preferably a λ / 4 plate (retardation film) in the range of 120 to 152 nm.

Formula _{(i): Ro = (n} x -n y) × d
Formula (ii): Rt = {(n _x + n _y ) / 2−n _z } × d
_Wherein, n x, _{n y} is a temperature 23 ° C. · RH 55% RH, 450 nm, 550 nm, maximum in-plane refractive index of the refractive index _{n x} (film in each of the 590 nm, the refractive index in a slow axis direction also referred to.), an n y _(refractive index in a direction perpendicular to the slow axis in the film plane), d is the film thickness (nm).

  Ro and Rt can be measured using an automatic birefringence meter. Using an automatic birefringence meter KOBRA-21ADH (manufactured by Oji Scientific Instruments), Ro is calculated by birefringence measurement at each wavelength in an environment of 23 ° C. and 55% RH.

  A circularly polarizing plate is obtained by laminating so that the angle between the slow axis of the λ / 4 plate and the transmission axis of the polarizer described later is substantially 45 °. “Substantially 45 °” means 40 to 50 °. The angle between the slow axis in the plane of the λ / 4 plate and the transmission axis of the polarizer is preferably 41 to 49 °, more preferably 42 to 48 °, and 43 to 47 °. Is more preferable, and it is most preferable that it is 44-46 degrees.

  In the present invention, the orientation angle θ needs to be in the range of 40 to 50 °. By setting the orientation angle θ in such a range, an effect of increasing the production efficiency of the polarizing plate can be obtained. Since there is no need to cut diagonally, film loss is reduced, and online bonding from roll to panel is possible.

  Here, “orientation angle θ” refers to an angle formed by the stretching direction of the film and the slow axis.

  The λ / 4 plate of the present invention has a compound represented by the general formula (PEI) or a log P value of 6.0 or less and a SP value in the Fedors method of 8.0 to 12.0. A compound having a log P value in the range of 6.1 to 12.0 and an SP value in the range of Fedors method in the range of 8.0 to 10.0, and a cellulose ester resin It is characterized by containing.

  Here, the “log P value” is a coefficient indicating the affinity of an organic compound for water and 1-octanol. 1-octanol / water partition coefficient P is a distribution equilibrium when a trace amount of compound is dissolved as a solute in a two-liquid solvent of 1-octanol and water, and is a ratio of the equilibrium concentration of the compound in each solvent. They are shown in the form of their logarithmic log P for base 10.

  That is, the “log P value” is a logarithmic value of the octanol / water partition coefficient and is known as an important parameter representing the hydrophilicity / hydrophobicity of a molecule. As a method for obtaining the log P value of a compound, it can be roughly classified into a method for obtaining by experimental measurement and a method for obtaining by calculation.

  When the logP value is actually measured, it can be obtained by actual measurement by the method described in the following document. The logP value can also be measured by a flask soaking method described in JIS Japanese Industrial Standard Z7260-107 (2000).

  When calculating a logP value by calculation, the logP value calculated by calculation (referred to as “CLogP value”) can be obtained by calculation using the fragment method described in the following literature or the following commercially available software packages 1 and 2. .

In the present application, whenever the logP value is discussed, this CLogP value is referred to. The numerical value of the logP value described in the specification etc. is the numerical value of the “ClogP value” calculated using the software package 2 below. .
Literature: C.I. Hansch and A.H. Leo, “Substitutants Constants for Correlation Analysis in Chemistry and Biology” (John Wiley & Sons, New York, 1969).
Software Package 1: MedChem Software (Release 3.54, Aug. 1991, Medicinal Chemistry Project, Pomona College, Clarmont, CA)
Software package 2: Chem Draw Ultra ver. 8.0. (April 2003, CambridgeSoft Corporation, USA)
In the present application, the “SP value” refers to an SP value obtained from an equation based on the Fedors method, which is a value represented by the square root of the molecular cohesive energy, the unit is (MPa) ^1/2 , and a value at 25 ° C. It is.

The SP value is represented by the following formula, as described in POLYMER ENGINEERING AND SCIENCE (published in 1974, Vol. 14, No. 2, pages 147 to 154).
Formula: SP = (ΔEv / V) ^1/2
(In the formula, ΔEv represents the energy of vaporization at a give temperature, and V represents the molar volume.)
Here, Delta] Ev and V are respectively represented by ΔEv = ΣΔe _i and V = ΣΔv _{i, e i} and _{v i} is the POLYMER ENGINEERING AND SCIENCE (1974 year published, Vol. 14, pp. NO.2,147～154) It is a value as described in Table 5 in the inside.

  the log P value is 6.0 or less and the SP value in the Fedors method is in the range of 8.0 to 12.0, or the log P value is in the range of 6.1 to 12.0, Specific examples of the compound having an SP value within the range of 8.0 to 10.0 by the Fedors method include methyl acrylate (MA), methyl methacrylate (MMA), hydroxyethyl such as UMM1001 manufactured by Soken Chemical Co., Ltd. Examples include acrylic compounds using methacrylate (HEMA), sugar esters such as saccharose octaacetate and glucose pentaacetate, triphenyl phosphate, and acetyl citrate tributyl. In addition, the aromatic polyester compound can also be adjusted to the above range by a method such as reducing the aromatic content in the molecular structure or reducing the molecular weight.

  It is preferable that content of the said compound exists in the range of 0.3-10.0% with respect to film solid content mass. When the compound is contained, the effect of improving the surface processing suitability, particularly the light-resistant adhesion of the hard coat or the antiglare hard coat can be obtained.

  The λ / 4 plate of the present invention preferably has a light transmittance of 380 nm of 10% or less. This is to prevent deterioration due to ultraviolet rays. For this reason, it is preferable that the λ / 4 plate of the present invention contains an ultraviolet absorber described later.

<Film substrate>
The λ / 4 plate of the present invention is characterized by containing a cellulose ester resin, and various resins can be used as the film substrate according to the present invention. A thermoplastic resin is mainly used. Here, the “thermoplastic resin” refers to a resin that becomes soft when heated to the glass transition temperature or melting point and can be molded into a desired shape.

  Polycarbonate, polyester, polyethersulfone, polyarylate, polyimide, polyolefin, etc. can be used as a resin for a general retardation film (optical film). Also, cellulose terephthalate such as polyethylene terephthalate, polyimide, polymethyl methacrylate, polysulfone, polyethylene, polyvinyl chloride, alicyclic olefin polymer, acrylic polymer, cellulose diacetate, cellulose triacetate, cellulose acetate propionate, etc. may be used. Good. In particular, cellulose esters such as cellulose diacetate, cellulose triacetate, and cellulose acetate propionate, acrylic polymers having a lactone ring structure, and the like are more preferable. These raw materials may be used alone or in combination with different thermoplastic resins. When mixed and used, a mixture of cellulose ester and acrylic polymer is more preferable.

  In the present invention, it is preferable that the film according to the present invention contains a resin having a positive intrinsic birefringence value. The “resin having a positive intrinsic birefringence value” refers to a resin having an increased refractive index in the stretched direction. Examples of the resin having a positive intrinsic birefringence value include cellulose acylate resins, cyclic olefin resins, and polycarbonate resins.

  The resin used as a raw material includes colorants such as pigments and dyes, optical brighteners, dispersants, heat stabilizers, light stabilizers, UV absorbers, antistatic agents, antioxidants, lubricants, solvents, and other compounding agents. It may be appropriately blended.

  The film may be a single layer film or a multilayer film.

  As the film, a raw film is mainly used, but it may be a film in which any one of longitudinal stretching, lateral stretching, and oblique stretching has already been carried out alone or multiple times.

<Cellulose ester resin>
The λ / 4 plate of the present invention is characterized by containing a cellulose ester resin (also simply referred to as “cellulose ester”).

  The cellulose ester that can be used in the present invention is at least selected from cellulose (di, tri) acetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate phthalate, and cellulose phthalate. One type is preferred.

  Among these, particularly preferable cellulose esters include cellulose triacetate, cellulose diacetate, cellulose propionate, cellulose butyrate, cellulose acetate propionate, and cellulose acetate butyrate.

In the present invention, it is preferable that X and Y satisfy the following formulas (1) and (2), where X is the acetyl group substitution degree and Y is the propionyl group substitution degree of the cellulose ester resin.
Formula (1): 2.0 ≦ (X + Y) ≦ 2.8
Formula (2): 0 ≦ Y ≦ 1.0
Moreover, the cellulose ester resin which satisfy | fills said Formula (1) and Formula (2) contains the cellulose ester resin which satisfy | fills following formula (1a) and said Formula (2), and cellulose ester resin which satisfy | fills following Formula (1b). A cellulose ester resin is preferred.
Formula (1a): 2.0 ≦ (X + Y) <2.5
Formula (1b): 2.5 ≦ (X + Y) ≦ 2.8
In addition, the glucose unit which comprises cellulose with a β-1,4-glycoside bond has free hydroxyl groups (hydroxyl groups) at the 2nd, 3rd and 6th positions. The cellulose ester resin according to the present invention is a polymer (polymer) obtained by esterifying some or all of these hydroxyl groups (hydroxyl groups) with an acyl group such as an acetyl group or a propionyl group.

  Here, “acyl group substitution degree” represents the total of the ratios of esterification of hydroxyl groups (hydroxyl groups) at the 2nd, 3rd and 6th positions of glucose as a repeating unit. Specifically, the degree of substitution is 1 when each of the hydroxyl groups (hydroxyl groups) at the 2nd, 3rd and 6th positions of cellulose is 100% esterified. Therefore, when all of the 2nd, 3rd and 6th positions of cellulose are 100% esterified, the degree of substitution is 3 at the maximum.

  In the present application, the “average acyl group substitution degree” refers to an acyl group substitution degree in which the acyl group substitution degree of a plurality of glucose units constituting the cellulose ester resin is expressed as an average value per unit.

  In addition, the measuring method of acyl group substitution degree can be measured according to ASTM-D817-96.

  Examples of the acyl group include acetyl group, propionyl group, butanoyl group, heptanoyl group, hexanoyl group, octanoyl group, decanoyl group, dodecanoyl group, tridecanoyl group, tetradecanoyl group, hexadecanoyl group, octadecanoyl group, and isobutanoyl. Group, tert-butanoyl group, cyclohexanecarbonyl group, oleoyl group, benzoyl group, naphthylcarbonyl group, cinnamoyl group and the like.

  Furthermore, as the cellulose ester resin used in the present invention, those having a weight average molecular weight Mw / number average molecular weight Mn ratio of 1.5 to 5.5 are preferably used, and particularly preferably 2.0 to 5.0, More preferably, it is 2.5-5.0, More preferably, 3.0-5.0 cellulose ester resin is used preferably.

  The raw material cellulose of the cellulose ester resin according to the present invention is not particularly limited, and examples thereof include cotton linter, wood pulp, and kenaf. Moreover, the cellulose ester resin obtained from them can be mixed and used in arbitrary ratios, respectively.

  The cellulose ester resin according to the present invention can be produced by a known method. Generally, cellulose is esterified by mixing cellulose as a raw material, a predetermined organic acid (such as acetic acid or propionic acid), an acid anhydride (such as acetic anhydride or propionic anhydride), and a catalyst (such as sulfuric acid). The reaction proceeds until the triester is formed. In the triester, three hydroxyl groups (hydroxyl groups) of the glucose unit are substituted with an acyl acid of an organic acid. When two kinds of organic acids are used at the same time, a mixed ester type cellulose ester such as cellulose acetate propionate or cellulose acetate butyrate can be produced. Subsequently, the cellulose triester is hydrolyzed to synthesize a cellulose ester having a desired degree of acyl substitution. Thereafter, the cellulose ester is completed through steps such as filtration, precipitation, washing with water, dehydration, and drying.

  Specifically, it can be synthesized with reference to the method described in JP-A-10-45804.

  In the present invention, 1 g of cellulose ester resin is added to 20 ml of pure water (electric conductivity 0.1 μS / cm or less, pH 6.8), and the pH is 6 when stirred in a nitrogen atmosphere at 25 ° C. for 1 hr. It is preferable that the electric conductivity is 1 to 100 μS / cm.

  In addition, it is possible to perform the kind of resin and the combination of molecular weight according to the use of this invention.

  The λ / 4 plate of the present invention may be obtained by appropriately mixing polymer components other than the cellulose ester described later. The polymer component to be mixed is preferably one having excellent compatibility with the cellulose ester, and the transmittance when formed into a film is preferably 80% or more, more preferably 90% or more, and further preferably 92% or more.

<acrylic resin>
Methacrylic resin is also contained in the acrylic resin which can be used for the resin film base material used for (lambda) / 4 board of this invention, a polarizing plate, etc. Although it does not restrict | limit especially as resin, What consists of 50-99 mass% of methyl methacrylate units and 1-50 mass% of other monomer units copolymerizable with this is preferable.

  Other monomers that can be copolymerized include alkyl methacrylates having 2 to 18 carbon atoms, alkyl acrylates having 1 to 18 carbon atoms, acrylic acid, methacrylic acid, and the like. Saturated acids, maleic acids, fumaric acids, unsaturated divalent carboxylic acids such as itaconic acid, aromatic vinyl compounds such as styrene, α-methylstyrene, and nucleus-substituted styrene, α, β- such as acrylonitrile, methacrylonitrile, etc. Examples thereof include unsaturated nitrile, maleic anhydride, maleimide, N-substituted maleimide, glutaric anhydride, and the like. These can be used alone or in combination of two or more.

  Among these, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, s-butyl acrylate, 2-ethylhexyl acrylate, and the like are preferable, and methyl acrylate and n-butyl acrylate are particularly preferably used.

  A commercially available thing can also be used as an acrylic resin. For example, Delpet 60N, 80N (Asahi Kasei Chemicals Co., Ltd.), Dianal BR52, BR80, BR83, BR85, BR88 (Mitsubishi Rayon Co., Ltd.), KT75 (Denki Kagaku Kogyo Co., Ltd.) and the like can be mentioned. .

<Cyclic olefin resin>
In the present invention, it is also preferable to use a cyclic olefin resin. Examples of the cyclic olefin resin include norbornene resins, monocyclic olefin resins, cyclic conjugated diene resins, vinyl alicyclic hydrocarbon resins, and hydrides thereof. Among these, norbornene-based resins can be suitably used because of their good transparency and moldability.

  Examples of the norbornene-based resin include a ring-opening polymer of a monomer having a norbornene structure, a ring-opening copolymer of a monomer having a norbornene structure and another monomer, a hydride thereof, and a norbornene structure. An addition polymer of a monomer having a monomer, an addition copolymer of a monomer having a norbornene structure and another monomer, or a hydride thereof.

  Among these, a ring-opening (co) polymer hydride of a monomer having a norbornene structure is particularly suitable from the viewpoints of transparency, moldability, heat resistance, low hygroscopicity, dimensional stability, lightness, and the like. Can be used.

Examples of the monomer having a norbornene structure include bicyclo [2.2.1] hept-2-ene (common name: norbornene) and tricyclo [4.3.0.1 ^2,5 ] deca-3,7-diene. (Common name: dicyclopentadiene), 7,8-benzotricyclo [4.3.0.1 ^2,5 ] dec-3-ene (common name: methanotetrahydrofluorene), tetracyclo [4.4.0. 1 ^2,5 . 1 ^7,10 ] dodec-3-ene (common name: tetracyclododecene), and derivatives of these compounds (for example, those having a substituent in the ring). Here, examples of the substituent include an alkyl group, an alkylene group, and a polar group. In addition, these substituents may be the same or different and a plurality may be bonded to the ring. Monomers having a norbornene structure can be used singly or in combination of two or more.

  Examples of the polar group include a hetero atom or an atomic group having a hetero atom. Examples of the hetero atom include an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, and a halogen atom. Specific examples of the polar group include a carboxyl group, a carbonyloxycarbonyl group, an epoxy group, a hydroxyl group, an oxy group, an ester group, a silanol group, a silyl group, an amino group, a nitrile group, and a sulfone group.

  Other monomers capable of ring-opening copolymerization with monomers having a norbornene structure include monocyclic olefins such as cyclohexene, cycloheptene, and cyclooctene and derivatives thereof, cyclic conjugated dienes such as cyclohexadiene, cycloheptadiene, and the like. And derivatives thereof.

  A ring-opening polymer of a monomer having a norbornene structure and a ring-opening copolymer of a monomer having a norbornene structure and another monomer copolymerizable with the monomer have a known ring-opening polymerization catalyst. It can be obtained by (co) polymerization in the presence.

  Examples of other monomers that can be addition copolymerized with a monomer having a norbornene structure include α-olefins having 2 to 20 carbon atoms such as ethylene, propylene, and 1-butene, and derivatives thereof; cyclobutene, cyclopentene, Cycloolefins such as cyclohexene and derivatives thereof; non-conjugated dienes such as 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, and the like. These monomers can be used alone or in combination of two or more. Among these, α-olefin is preferable and ethylene is more preferable.

  An addition polymer of a monomer having a norbornene structure and an addition copolymer of another monomer copolymerizable with a monomer having a norbornene structure can be used in the presence of a known addition polymerization catalyst. It can be obtained by polymerization.

  A hydrogenated product of a ring-opening polymer of a monomer having a norbornene structure, a hydrogenated product of a ring-opening copolymer of a monomer having a norbornene structure and another monomer capable of ring-opening copolymerization thereof, Hydrogenated products of addition polymers of monomers having a norbornene structure, and hydrogenated products of addition copolymers of monomers having a norbornene structure and other monomers capable of addition copolymerization with these A known hydrogenation catalyst containing a transition metal such as nickel or palladium is added to the polymer solution, and the carbon-carbon unsaturated bond is preferably hydrogenated by 90% or more.

Among norbornene-based resins, as repeating units, X: bicyclo [3.3.0] octane-2,4-diyl-ethylene structure and Y: tricyclo [4.3.0.1 ^2,5 ] decane-7 , 9-diyl-ethylene structure, the content of these repeating units is 90% by mass or more based on the entire repeating units of the norbornene resin, and the content ratio of X and the content ratio of Y The ratio of X: Y is preferably 100: 0 to 40:60. By using such a resin, it is possible to obtain a retardation film (optical film) having no dimensional change over a long period of time and having excellent optical property stability.

  The molecular weight of the cyclic olefin resin used in the present invention is appropriately selected according to the purpose of use. Polyisoprene or polystyrene-equivalent weight average molecular weight (Mw) measured by gel permeation chromatography using cyclohexane (toluene if the polymer resin does not dissolve) as a solvent, usually 20,000 to 150,000. . Preferably it is 25,000-100,000, More preferably, it is 30,000-80,000. When the weight average molecular weight is in such a range, the mechanical strength and molding processability of the film are highly balanced and suitable.

  The glass transition temperature of the cyclic olefin resin may be appropriately selected according to the purpose of use. From the viewpoint of durability and stretchability, it is preferably in the range of 130 to 160 ° C, more preferably 135 to 150 ° C.

  The molecular weight distribution (weight average molecular weight (Mw) / number average molecular weight (Mn)) of the cyclic olefin resin is 1.2 to 3.5, preferably 1.5 to 3.0, from the viewpoint of relaxation time, productivity, and the like. More preferably, it is 1.8 to 2.7.

The cyclic olefin resin used in the present invention preferably has an absolute value of photoelastic coefficient of 10 × 10 ⁻¹² Pa ⁻¹ or less, more preferably 7 × 10 ⁻¹² Pa ⁻¹ or less, and more preferably 4 × 10. It is particularly preferably ⁻¹² Pa ⁻¹ or less. The photoelastic coefficient C is a value represented by C = Δn / σ where birefringence is Δn and stress is σ.

  In the present invention, it is preferable that the cyclic olefin resin does not substantially contain particles. Here, “substantially free of particles” means that even if particles are added to a film made of a cyclic olefin resin, the amount of increase in haze from the non-added state is allowed to be in the range of 0.05% or less. Means you can. In particular, the alicyclic polyolefin resin lacks affinity with many organic particles and inorganic particles. Therefore, when a cyclic olefin resin film to which particles exceeding the above range are added is stretched, voids are easily generated, and as a result, There is a risk that a significant increase in haze may occur.

<Polycarbonate resin>
In the present invention, various known polycarbonate resins can also be used. In the present invention, it is particularly preferable to use an aromatic polycarbonate. There is no restriction | limiting in particular about the said aromatic polycarbonate, and there will be no restriction | limiting in particular if it is an aromatic polycarbonate from which the various characteristics of a desired film are acquired.

  In general, a polymer material collectively referred to as polycarbonate is a generic term for a polymer material in which a polycondensation reaction is used in its synthesis method and the main chain is linked by a carbonic acid bond. , Phosgene, diphenyl carbonate and the like obtained by polycondensation. Usually, an aromatic polycarbonate represented by a repeating unit having 2,2-bis (4-hydroxyphenyl) propane called bisphenol-A as a bisphenol component is preferably selected, and various bisphenol derivatives should be appropriately selected. Thus, an aromatic polycarbonate copolymer can be constituted.

  In addition to this bisphenol-A, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 9,9-bis (4-hydroxyphenyl) fluorene, 1,1 -Bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxyphenyl) -2-phenyl Ethane, 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane, bis (4-hydroxyphenyl) diphenylmethane, bis (4-hydroxyphenyl) sulfide, bis ( 4-hydroxyphenyl) sulfone, 1,1-bis (4-hydroxyphenyl) -3,3,5-tri Mention may be made of a chill cyclohexane, and the like.

  It is also possible to use an aromatic polyester carbonate partially containing terephthalic acid and / or isophthalic acid components. By using such a structural unit as a part of the structural component of the aromatic polycarbonate composed of bisphenol-A, the properties of the aromatic polycarbonate, such as heat resistance and solubility, can be improved. The present invention is also effective for coalescence.

  If the aromatic polycarbonate used here has a viscosity average molecular weight of 10,000 or more and 200,000 or less, it is suitably used. A viscosity average molecular weight of 20,000 to 120,000 is particularly preferred. If a resin having a viscosity average molecular weight lower than 10,000 is used, the mechanical strength of the resulting film may be insufficient, and if it has a high molecular weight of 400000 or more, the viscosity of the dope becomes too large, causing problems in handling. The viscosity average molecular weight can be measured by commercially available high performance liquid chromatography.

  The glass transition temperature of the aromatic polycarbonate according to the present invention is preferably 200 ° C. or higher in order to obtain a highly heat-resistant film, and more preferably 230 ° C. or higher. These can be obtained by appropriately selecting the copolymerization component. The glass transition temperature can be measured with a DSC apparatus (differential scanning calorimetric analyzer). For example, the baseline is unevenly determined by a temperature rising condition of 10 ° C./min with RDC220 manufactured by Seiko Instruments Inc. It is the temperature that starts

  In the present invention, the solvent used for the dope composition containing the aromatic polycarbonate is a mixed solvent containing 4 to 14 parts by mass of methylene chloride and a linear or branched aliphatic alcohol having 1 to 6 carbon atoms. It is preferable.

  The mixing amount of the linear or branched aliphatic alcohol having 1 to 6 carbon atoms is preferably 4 to 12 parts by mass. By using such a mixed solvent, the web is peeled off at a higher residual solvent concentration than before, thereby suppressing the generation of strong static electricity when the web is peeled off, thereby causing damage to the belt, film streaks, unevenness, and minuteness. Scratches can be prevented from occurring.

  The type of alcohol added is limited by the solvent used. It is a necessary condition that the alcohol and the solvent are compatible. These may be added alone or in combination of two or more. The alcohol in the present invention is preferably a linear or branched aliphatic alcohol having 1 to 6, preferably 1 to 4, more preferably 2 to 4 carbon atoms. Specific examples include methanol, ethanol, isopropanol, and tertiary butanol. Of these, ethanol, isopropanol, and tertiary butanol can achieve almost the same effect, but methanol is slightly less effective. Although the reason is not clear, it is presumed that the boiling point of the solvent, that is, the ease of flying during drying is related. Higher alcohols higher than that are not preferred because they have a high boiling point and are likely to remain after film formation.

  The amount of alcohol added must be carefully selected. These alcohols are completely poor in solubility in aromatic polycarbonate and are completely poor solvents. Therefore, it cannot be added too much, and should be the minimum amount that provides satisfactory peelability. As mentioned above, it is 4-14 mass parts with respect to a methylene chloride, Preferably it is 4-12 mass parts. When the addition amount is in the range of 4 to 14 parts by mass with respect to the amount of methylene chloride, the solubility of the solvent in the polymer and the dope stability are improved, and the effect of improving the peelability is increased.

  The present invention comprises the above methylene chloride and aliphatic alcohol in the dope composition, but other solvents can also be used. The remaining solvent is not particularly limited as long as it dissolves the aromatic polycarbonate at a high concentration and is compatible with alcohol, and is a low-boiling solvent. For example, as a solvent having a solubility in aromatic polycarbonate, in addition to methylene chloride, halogen solvents such as chloroform, 1,2-dichloroethane, 1,1,2-trichloroethane, chlorobenzene, 1,3-dioxolane, 1, Examples include cyclic ether solvents such as 4-dioxane and tetrahydrofuran, and ketone solvents such as cyclohexanone.

  When using other solvent, there is no limitation in particular and it may use it in consideration of an effect. The effects here include mixing the solvent without sacrificing solubility and stability, for example, improving the surface properties of the film formed by the solution casting method (leveling effect), evaporation rate and system These include viscosity adjustment and crystallization suppression effects. What is necessary is just to determine the kind and addition amount of the solvent to mix by the degree of these effects, and you may use 1 type, or 2 or more types as a solvent to mix.

  Other solvents preferably used include halogen solvents such as chloroform and 1,2-dichloroethane, hydrocarbon solvents such as toluene and xylene, ketone solvents such as acetone, methyl ethyl ketone, and cyclohexanone, and ethyl acetate and butyl acetate. Examples include ester solvents, ether solvents such as ethylene glycol dimethyl ether and methoxyethyl acetate.

  The dope composition according to the present invention may be prepared by any method as long as a transparent solution having a low haze is obtained as a result. A predetermined amount of alcohol may be added to the aromatic polycarbonate solution dissolved in a certain solvent in advance, or the aromatic polycarbonate may be dissolved in a mixed solvent containing alcohol. However, as described above, since alcohol is a poor solvent, the method of adding the latter after the former may cause clouding of the dope due to the precipitation of the polymer. Therefore, the method of dissolving in the latter mixed solvent is preferable.

<Polyester resin>
The polyester resin that can be used in the present invention is obtained by polymerizing a dicarboxylic acid and a diol, and 70% or more of dicarboxylic acid structural units (constituent units derived from dicarboxylic acid) are derived from aromatic dicarboxylic acid, and 70% or more of the diol constituent units (constituent units derived from the diol) are derived from the aliphatic diol.

  The proportion of the structural unit derived from the aromatic dicarboxylic acid is 70% or more, preferably 80% or more, more preferably 90% or more.

  The proportion of the structural unit derived from the aliphatic diol is 70% or more, preferably 80% or more, and more preferably 90% or more. Two or more polyester resins may be used in combination.

  Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, naphthalenedicarboxylic acid such as 2,7-naphthalenedicarboxylic acid, and 4,4′-biphenyldicarboxylic acid. 3,4'-biphenyldicarboxylic acid and the like and ester-forming derivatives thereof.

  As the polyester resin, aliphatic dicarboxylic acids such as adipic acid, azelaic acid, and sebacic acid, and monocarboxylic acids such as benzoic acid, propionic acid, and butyric acid can be used without departing from the object of the present invention.

  Examples of the aliphatic diol include ethylene glycol, 1,3-propylene diol, 1,4-butanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol, and the like, and ester-forming derivatives thereof.

  As the polyester resin, monoalcohols such as butyl alcohol, hexyl alcohol, and octyl alcohol, and polyhydric alcohols such as trimethylolpropane, glycerin, and pentaerythritol can be used as long as the object of the present invention is not impaired.

  A known esterification method or transesterification method can be applied to the production of the polyester resin. Examples of the polycondensation catalyst used in the production of the polyester resin include known antimony compounds such as antimony trioxide and antimony pentoxide, germanium compounds such as germanium oxide, titanium compounds such as titanium acetate, and aluminum compounds such as aluminum chloride. Although it can, it is not limited to these.

  Preferred polyester resins include polyethylene terephthalate resin, polyethylene terephthalate-isophthalate copolymer resin, polyethylene-1,4-cyclohexanedimethylene-terephthalate copolymer resin, polyethylene-2,6-naphthalene dicarboxylate resin, polyethylene-2, 6-naphthalene dicarboxylate-terephthalate copolymer resin, polyethylene-terephthalate-4,4'-biphenyldicarboxylate resin, poly-1,3-propylene-terephthalate resin, polybutylene terephthalate resin, polybutylene-2,6-naphthalene There are dicarboxylate resins and the like.

  More preferable polyester resins include polyethylene terephthalate resin, polyethylene terephthalate-isophthalate copolymer resin, polyethylene-1,4-cyclohexanedimethylene-terephthalate copolymer resin, polybutylene terephthalate resin, and polyethylene-2,6-naphthalene dicarboxylate. Resin.

  The intrinsic viscosity of the polyester resin (phenol / 1,1,2,2-tetrachloroethane = value measured at 25 ° C. in a 60/40 mass ratio mixed solvent) is preferably 0.7 to 2.0 dl / g, more Preferably it is 0.8-1.5 dl / g. Since the molecular weight of the polyester resin is sufficiently high when the intrinsic viscosity is 0.7 or more, the molded product comprising the polyester resin composition obtained by using the polyester resin has mechanical properties necessary for the molded product and is transparent. Property is improved. When the intrinsic viscosity is 2.0 or less, the moldability is good.

<Compound represented by formula (PEI): aromatic group-terminated polyester compound>
The λ / 4 plate of the present invention is characterized by containing a compound represented by the following general formula (PEI) (hereinafter also referred to as “aromatic group-terminated polyester compound”) and a cellulose ester resin. In the present invention, by containing the compound represented by the general formula (PEI), the phase difference can be freely controlled, the control of the λ / 4 target phase difference is easy, and the hardness of the film is increased. The effect of improving the hardness when the applied hard coat or antiglare hard coat is surface-treated is obtained.
Formula (PEI): B- (GA) _n -GB
(B represents a benzene monocarboxylic acid residue. G represents an alkylene glycol residue having 2 to 12 carbon atoms, an aryl glycol residue having 6 to 12 carbon atoms, or an oxyalkylene glycol residue having 4 to 12 carbon atoms. And A represents an alkylene dicarboxylic acid residue having 4 to 12 carbon atoms or an aryl dicarboxylic acid residue having 6 to 12 carbon atoms, and n represents an integer of 0 or more.)
In the general formula (PEI), an arylcarboxylic acid residue represented by B and an alkylene glycol residue or oxyalkylene glycol residue or arylglycol residue represented by G, an alkylenedicarboxylic acid residue represented by A or It is composed of an aryl dicarboxylic acid residue, and can be obtained by the same reaction as a normal polyester compound.

  As the arylcarboxylic acid component of the aromatic group-terminated polyester-based compound used in the present invention, for example, benzoic acid, p-tert-butylbenzoic acid, orthotoluic acid, metatoluic acid, p-toluic acid, dimethylbenzoic acid, ethylbenzoic acid, There are normal propyl benzoic acid, aminobenzoic acid, acetoxybenzoic acid and the like, and these can be used as one kind or a mixture of two or more kinds, respectively.

  Examples of the alkylene glycol component having 2 to 12 carbon atoms of the aromatic group-terminated polyester compound that can be used in the present invention include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, and 1,2-butanediol. 1,3-butanediol, 1,2-propanediol, 2-methyl 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propane Diol (neopentyl glycol), 2,2-diethyl-1,3-propanediol (3,3-dimethylolpentane), 2-n-butyl-2-ethyl-1,3-propanediol (3,3-di) Methylol heptane), 3-methyl-1,5-pentanediol 1,6-hexanediol, 2,2,4-trimethyl 1 There are 3-pentanediol, 2-ethyl 1,3-hexanediol, 2-methyl 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecanediol, etc. These glycols are used as one kind or a mixture of two or more kinds.

  In particular, an alkylene glycol having 2 to 12 carbon atoms is particularly preferable because of excellent compatibility with a cellulose ester.

  Examples of the oxyalkylene glycol component having 4 to 12 carbon atoms of the aromatic group-terminated polyester compound include diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and tripropylene glycol. Can be used as one or a mixture of two or more.

  Examples of the alkylene dicarboxylic acid component having 4 to 12 carbon atoms of the aromatic group-terminated polyester compound include succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid. These are each used as one kind or a mixture of two or more kinds.

  Examples of the arylene dicarboxylic acid component having 6 to 12 carbon atoms include phthalic acid, terephthalic acid, isophthalic acid, 1,5 naphthalene dicarboxylic acid, and 1,4 naphthalene dicarboxylic acid.

  In the aromatic group-terminated polyester compound used in the present invention, n is preferably 1 or more and 100 or less, and the number average molecular weight is preferably 300 to 1500, more preferably 400 to 1000. .

  The acid value is 0.5 mgKOH / g or less, the hydroxyl (hydroxyl) value is 25 mgKOH / g or less, more preferably the acid value is 0.3 mgKOH / g or less, and the hydroxyl (hydroxyl) value is 15 mgKOH / g or less. is there.

  The aromatic group-terminated polyester compound represented by the general formula (PEI) according to the present invention is preferably contained in an amount of 0.5 to 30% by mass with respect to the cellulose ester resin.

  Specific examples of the aromatic group-terminated polyester compound that can be used in the present invention are shown below, but the present invention is not limited thereto.

  The cellulose ester film according to the present invention contains the sugar ester compound according to the present invention in an amount of 0.5 to 30% by mass of the cellulose ester film in order to suppress the fluctuation of the retardation value and stabilize the display quality. It is preferable to contain 5-30 mass% especially.

  The content of the aromatic group-terminated polyester compound represented by the general formula (PEI) according to the present invention and the sugar ester compound can be selected in a mass ratio of 99: 1 to 1:99, both compounds The total amount of is preferably 1 to 40% by mass relative to the cellulose ester resin.

<Compound represented by formula (PEII): hydroxyl group-terminated polyester>
In the present invention, various polyester compounds conventionally contained in optical films can be used. For example, as the polyester compound, a polyester having a hydroxyl group at the terminal portion of the chemical structural formula as represented by the following general formula (PEII) (referred to as “hydroxyl-terminated polyester”) can also be used.

(In the formula, B represents a linear or branched alkylene having 2 to 6 carbon atoms or a cycloalkylene group. A represents an aromatic ring having 6 to 14 carbon atoms. N represents one or more. Represents a natural number.)
The compound represented by the above formula is obtained from a dicarboxylic acid having an aromatic ring (also referred to as “aromatic dicarboxylic acid”) and a linear or branched alkylene or cycloalkylene diol having 2 to 6 carbon atoms. The terminal is not sealed with a monocarboxylic acid.

  Examples of the aromatic dicarboxylic acid having 6 to 16 carbon atoms include phthalic acid, isophthalic acid, terephthalic acid, 1,5-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3- And naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,8-naphthalenedicarboxylic acid, 2,2'-biphenyldicarboxylic acid, 4,4'-biphenyldicarboxylic acid, and the like. Among these, 2,6-naphthalenedicarboxylic acid and 4,4′-biphenyldicarboxylic acid are preferable.

  Examples of the linear or branched alkylene or cycloalkylene diol having 2 to 6 carbon atoms include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, and 1,3-butanediol. 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol 1,4-cyclohexanedimethanol and the like. Among these, ethanediol, 1,2-propanediol, 1,3-propanediol, and 1,3-butanediol are preferable.

  Among these, A is preferably a naphthalene ring or a biphenyl ring which may have a substituent, from the viewpoint of obtaining the effects of the present invention. Here, the substituent is an alkyl group having 1 to 6 carbon atoms, an alkenyl group, or an alkoxyl group.

  The hydroxyl (hydroxyl) value (OH value) of the polyester compound according to the present invention is preferably 100 mgKOH / g or more and 500 mgKOH / g or less, and more preferably 170 mgKOH / g to 400 mgKOH / g. Whether the hydroxyl (hydroxyl) value is larger or smaller than this range, the compatibility with cellulose acetate having a low acetyl substitution degree is lowered.

  If it is larger than this range, the hydrophobicity of the polyester compound becomes larger. If it is smaller than this range, the intermolecular interaction (hydrogen bonding, etc.) between the polyester compounds becomes stronger, so that precipitation in the film proceeds. it is conceivable that.

  Moreover, the measurement of a hydroxyl (hydroxyl group) value can apply the acetic anhydride method etc. of Japanese Industrial Standard JISK1557-1: 2007.

  The number average molecular weight (Mn) of the polyester compound according to the present invention can be calculated from the following formula.

Mn = (number of hydroxyl groups (hydroxyl groups) in the molecule) × 56110 / (hydroxyl (hydroxyl group) value)
= 2 × 56110 / (hydroxyl (hydroxyl group) value)
The polyester compound according to the present invention is either a hot melt condensation method by a polyesterification reaction or transesterification reaction of the above dicarboxylic acid and a diol by a conventional method, or an interfacial condensation method of an acid chloride of these acids and glycols. It can be easily synthesized by a method.

  Below, the polyester compound which concerns on this invention is illustrated.

  The compound represented by the general formula (PEII) is preferably added in an amount of 1% by mass to less than 5% by mass with respect to cellulose acetate.

(Carboxylic acid sugar ester compound)
The λ / 4 plate of the present invention preferably contains a carboxylic acid sugar ester compound as one of its constituent components. The said compound can acquire the effect that water resistance improves by containing compatibility with a cellulose excellently. Since it can be contained in a large amount, it is supplemented with this compound when water resistance is insufficient with other additives.

  In the present application, the “carboxylic acid sugar ester compound” refers to a compound having an ester bond derived from a hydroxyl group (hydroxyl group) of a saccharide and a carboxyl group of a carboxylic acid.

  Examples of the carboxylic acid structural unit constituting the carboxylic acid sugar ester compound include aromatic carboxylic acids such as methylbenzoic acid (toluic acid), aromatic substituted aliphatic carboxylic acids such as phenylacetic acid, and fatty acids such as stearic acid. These carboxylic acids may be substituted with an alkoxy group, an alkylthio group, a halogen atom, a cyano group, or a nitro group.

  Examples of preferred aromatic carboxylic acids include aromatic monocarboxylic acids, cinnamic acid, benzylic acid, biphenylcarboxylic acid, naphthalenecarboxylic acid having an alkyl group or alkoxy group introduced into the benzene ring of benzoic acid such as benzoic acid or toluic acid. An aromatic monocarboxylic acid having two or more benzene rings such as acid and tetralincarboxylic acid, or a derivative thereof can be mentioned, and more specifically, xylyl acid, hemelic acid, mesitylene acid, prenylic acid, γ -Isoduric acid, duryl acid, mesitic acid, α-isoduric acid, cumic acid, α-toluic acid, hydroatropic acid, atropic acid, hydrocinnamic acid, salicylic acid, o-anisic acid, m-anisic acid, p-anisic acid, Creosote acid, o-homosalicylic acid, m-homosalicylic acid, p-homosalicylic acid, o-pyrocatechuic acid β-resorcylic acid, vanillic acid, isovanillic acid, veratromic acid, o-veratrumic acid, gallic acid, asaronic acid, mandelic acid, homoanisic acid, homovanillic acid, homoveratrumic acid, o-homoveratormic acid, phthalonic acid, p-coumaric acid Among them, benzoic acid is particularly preferable.

  Preferred aliphatic carboxylic acids include acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanecarboxylic acid, undecylic acid, lauric acid, Tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, mellicic acid, laccellic acid, etc., undecylen Examples thereof include unsaturated fatty acids such as acid, oleic acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid and octenoic acid.

  The saccharides constituting the carboxylic acid sugar ester compound usually include monosaccharides (monosaccharides), disaccharides (disaccharides), and oligosaccharides bonded with 3 to 6 monosaccharides, and among them, the number of carbon atoms is 6 ~ 48 saccharides are preferred, and monosaccharides and disaccharides are more preferred. Specific examples of monosaccharides include glucose, fructose, arabinose, mannose, and sorbitol, and examples of disaccharides include sucrose and maltose. From the viewpoint of supplying raw materials, glucose, fructose and sucrose are particularly preferable, and sucrose is most preferable.

  These saccharides have a plurality of hydroxyl groups (hydroxyl groups) in the molecule, and can form ester bonds with the aforementioned carboxylic acid structural units.

  In particular, when sucrose is used as a saccharide, there are 8 hydroxyl groups (hydroxyl groups) in the sucrose molecule, but the average number of ester bonds (also referred to as “average ester substitution degree”) is 1. 0.0 or more, preferably 3.0 to 7.5, and more preferably 3.0 to 6.0.

  In the present invention, it is particularly preferable to contain a compound represented by the following general formula (1) and having a total average substitution degree in the range of 3.0 to 7.5.

In general formula (1), R _{1 to} R ₈ represent a hydrogen atom, a substituted or unsubstituted alkylcarbonyl group, or a substituted or unsubstituted arylcarbonyl group, and R _{1 to} R ₈ are the same. It may or may not be.

Preferable specific examples of the compound represented by the general formula (1) include compounds shown in Table 1. In addition, R described in the following table represents any one of R _{1 to} R ₈ . As the substituent for the alkylcarbonyl group and the arylcarbonyl group, substituents such as a phenyl group and an alkoxy group included in the alkylcarbonyl group and the arylcarbonyl group shown in the following table are preferable.

  Although the compound represented by the said General formula (1) and a reference compound are described below, it is not limited to these.

  (Synthesis Example: Synthesis of Compound According to the Present Invention)

A four-headed colben equipped with a stirrer, a reflux condenser, a thermometer, and a nitrogen gas inlet tube was mixed with 34.2 g (0.1 mol) of sucrose, 180.8 g (0.8 mol) of benzoic anhydride, 379. 7 g (4.8 mol) was charged, the temperature was raised while bubbling nitrogen gas from a nitrogen gas introduction tube with stirring, and an esterification reaction was carried out at 70 ° C. for 5 hours. Next, the inside of the Kolben was depressurized to 4 × 10 ² Pa or less, and after excess pyridine was distilled off at 60 ° C., the inside of the Kolben was depressurized to 1.3 × 10 Pa or less and the temperature was raised to 120 ° C. Most of the acid and benzoic acid formed were distilled off. Then, 1 L of toluene and 300 g of a 0.5% by mass aqueous sodium carbonate solution were added, and the mixture was stirred at 50 ° C. for 30 minutes and then allowed to stand to separate a toluene layer. Finally, 100 g of water is added to the collected toluene layer, and after washing with water at room temperature for 30 minutes, the toluene layer is separated, and toluene is distilled off at 60 ° C. under reduced pressure (4 × 10 ² Pa or less). A mixture of A-1, A-2, A-3, A-4 and A-5 was obtained. When the obtained mixture was analyzed by HPLC and LC-MASS, A-1 was 7% by mass, A-2 was 58% by mass, A-3 was 23% by mass, A-4 was 9% by mass, A-5. Was 3% by mass. A part of the obtained mixture was purified by column chromatography using silica gel to obtain A-1, A-2, A-3, A-4 and A-5 having a purity of 100%, respectively. It was.

  The total average substitution degree of the compound represented by the general formula (1) added to the λ / 4 plate (retardation film) in the present invention is 3.0 to 7.5. It is preferable that it is 3.0-6.0. The substitution degree distribution may be adjusted to the desired substitution degree by adjusting the esterification reaction time or mixing compounds having different substitution degrees.

(Phase difference agent)
In the present invention, a retardation (also referred to as “retardation”) developing agent may be included. The phase difference (retardation) developing agent can be contained, for example, in a proportion of 0.5 to 10% by mass, and more preferably in a proportion of 2 to 6% by mass. By adopting a retardation developing agent, high Re developability can be obtained at a low draw ratio. The type of retardation developing agent is not particularly defined, but examples thereof include those made of rod-like or discotic compounds. As the rod-like or discotic compound, a compound having at least two aromatic rings can be preferably used as a retardation developing agent. The addition amount of the retardation developing agent composed of the rod-shaped compound is preferably 0.5 to 10 parts by mass, and 2 to 6 parts by mass with respect to 100 parts by mass of the polymer component containing the cellulose ester. Is more preferable.

  The discotic retardation developing agent is preferably used in a range of 0.5 to 10 parts by mass, and in a range of 1 to 8 parts by mass with respect to 100 parts by mass of the polymer component containing the cellulose ester. It is more preferable to use in the range of 2 to 6 parts by mass.

  Two or more kinds of retardation developing agents may be used in combination.

  The phase difference (retardation) developing agent preferably has maximum absorption in the wavelength region of 250 to 400 nm, and preferably has substantially no absorption in the visible region.

  The discotic compound will be described. As the discotic compound, a compound having at least two aromatic rings can be used.

  In the present specification, the “aromatic ring” includes an aromatic hetero ring in addition to an aromatic hydrocarbon ring.

  The aromatic hydrocarbon ring is particularly preferably a 6-membered ring (that is, a benzene ring).

  The aromatic heterocycle is generally an unsaturated heterocycle. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring. Aromatic heterocycles generally have the most double bonds. As the hetero atom, a nitrogen atom, an oxygen atom and a sulfur atom are preferable, and a nitrogen atom is particularly preferable. Examples of aromatic heterocycles include furan ring, thiophene ring, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, pyrazole ring, furazane ring, triazole ring, pyran ring, pyridine ring , Pyridazine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring.

  As the aromatic ring, a benzene ring, a condensed benzene ring, and biphenyls are preferable. In particular, a 1,3,5-triazine ring is preferably used. Specifically, for example, compounds disclosed in JP-A No. 2001-166144 are preferably used.

  The number of carbon atoms of the aromatic ring contained in the retardation developing agent is preferably 2-20, more preferably 2-12, further preferably 2-8, and 2-6. Most preferably.

  The bonding relationship between two aromatic rings can be classified into (a) when forming a condensed ring, (b) when directly connecting with a single bond, and (c) when connecting via a linking group (for aromatic rings). , Spiro bonds cannot be formed). The connection relationship may be any of (a) to (c).

  Examples of the condensed ring (a condensed ring of two or more aromatic rings) include an indene ring, a naphthalene ring, an azulene ring, a fluorene ring, a phenanthrene ring, an anthracene ring, an acenaphthylene ring, a biphenylene ring, a naphthacene ring, Pyrene ring, indole ring, isoindole ring, benzofuran ring, benzothiophene ring, indolizine ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring, purine ring, indazole ring, chromene ring, quinoline ring, isoquinoline Ring, quinolidine ring, quinazoline ring, cinnoline ring, quinoxaline ring, phthalazine ring, pteridine ring, carbazole ring, acridine ring, phenanthridine ring, xanthene ring, phenazine ring, phenothiazine ring, phenoxathiin ring, phenoxazine ring and thiantole Ring is included. Naphthalene ring, azulene ring, indole ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring and quinoline ring are preferred.

  The single bond (b) is preferably a bond between carbon atoms of two aromatic rings. Two aromatic rings may be bonded by two or more single bonds to form an aliphatic ring or a non-aromatic heterocyclic ring between the two aromatic rings.

The linking group in (c) is also preferably bonded to carbon atoms of two aromatic rings. The linking group is preferably an alkylene group, an alkenylene group, an alkynylene group, —CO—, —O—, —NH—, —S—, or a combination thereof. Examples of linking groups composed of combinations are shown below. In addition, the relationship between the left and right in the following examples of the linking group may be reversed.
c1: -CO-O-
c2: —CO—NH—
c3: -alkylene-O-
c4: —NH—CO—NH—
c5: —NH—CO—O—
c6: —O—CO—O—
c7: -O-alkylene-O-
c8: -CO-alkenylene-
c9: -CO-alkenylene-NH-
c10: -CO-alkenylene-O-
c11: -alkylene-CO-O-alkylene-O-CO-alkylene-
c12: -O-alkylene-CO-O-alkylene-O-CO-alkylene-O-
c13: -O-CO-alkylene-CO-O-
c14: -NH-CO-alkenylene-
c15: -O-CO-alkenylene-
The aromatic ring and the linking group may have a substituent.

  Examples of substituents include halogen atoms (F, Cl, Br, I), hydroxyl groups, carboxyl groups, cyano groups, amino groups, nitro groups, sulfo groups, carbamoyl groups, sulfamoyl groups, ureido groups, alkyl groups, alkenyls. Group, alkynyl group, aliphatic acyl group, aliphatic acyloxy group, alkoxy group, alkoxycarbonyl group, alkoxycarbonylamino group, alkylthio group, alkylsulfonyl group, aliphatic amide group, aliphatic sulfonamido group, aliphatic substituted amino group An aliphatic substituted carbamoyl group, an aliphatic substituted sulfamoyl group, an aliphatic substituted ureido group, and a non-aromatic heterocyclic group.

  It is preferable that the alkyl group has 1 to 8 carbon atoms. A chain alkyl group is preferable to a cyclic alkyl group, and a linear alkyl group is particularly preferable. The alkyl group may further have a substituent (for example, a hydroxyl group, a carboxy group, an alkoxy group, an alkyl-substituted amino group). Examples of alkyl groups (including substituted alkyl groups) include methyl, ethyl, n-butyl, n-hexyl, 2-hydroxyethyl, 4-carboxybutyl, 2-methoxyethyl and 2-methoxyethyl. Each group of a diethylaminoethyl group is included.

  The alkenyl group preferably has 2 to 8 carbon atoms. A chain alkenyl group is preferable to a cyclic alkenyl group, and a linear alkenyl group is particularly preferable. The alkenyl group may further have a substituent. Examples of the alkenyl group include a vinyl group, an allyl group, and a 1-hexenyl group.

  The alkynyl group preferably has 2 to 8 carbon atoms. A chain alkynyl group is preferable to a cyclic alkynyl group, and a linear alkynyl group is particularly preferable. The alkynyl group may further have a substituent. Examples of the alkynyl group include ethynyl group, 1-butynyl group and 1-hexynyl group.

  The number of carbon atoms in the aliphatic acyl group is preferably 1-10. Examples of the aliphatic acyl group include an acetyl group, a propanoyl group, and a butanoyl group.

  The number of carbon atoms in the aliphatic acyloxy group is preferably 1-10. Examples of the aliphatic acyloxy group include an acetoxy group.

  The number of carbon atoms of the alkoxy group is preferably 1-8. The alkoxy group may further have a substituent (for example, an alkoxy group). Examples of the alkoxy group (including a substituted alkoxy group) include a methoxy group, an ethoxy group, a butoxy group, and a methoxyethoxy group.

  The number of carbon atoms of the alkoxycarbonyl group is preferably 2-10. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group.

  The number of carbon atoms of the alkoxycarbonylamino group is preferably 2-10. Examples of the alkoxycarbonylamino group include a methoxycarbonylamino group and an ethoxycarbonylamino group.

  The alkylthio group preferably has 1 to 12 carbon atoms. Examples of the alkylthio group include a methylthio group, an ethylthio group, and an octylthio group.

  The alkylsulfonyl group preferably has 1 to 8 carbon atoms. Examples of the alkylsulfonyl group include a methanesulfonyl group and an ethanesulfonyl group.

  The number of carbon atoms in the aliphatic amide group is preferably 1-10. Examples of the aliphatic amide group include acetamide.

  The number of carbon atoms of the aliphatic sulfonamide group is preferably 1-8. Examples of the aliphatic sulfonamide group include a methane sulfonamide group, a butane sulfonamide group, and an n-octane sulfonamide group.

  The number of carbon atoms of the aliphatic substituted amino group is preferably 1-10. Examples of the aliphatic substituted amino group include a dimethylamino group, a diethylamino group, and a 2-carboxyethylamino group.

  The number of carbon atoms in the aliphatic substituted carbamoyl group is preferably 2-10. Examples of the aliphatic substituted carbamoyl group include a methylcarbamoyl group and a diethylcarbamoyl group.

  The number of carbon atoms in the aliphatic substituted sulfamoyl group is preferably 1-8. Examples of the aliphatic substituted sulfamoyl group include a methylsulfamoyl group and a diethylsulfamoyl group.

  The number of carbon atoms in the aliphatic substituted ureido group is preferably 2-10. Examples of the aliphatic substituted ureido group include a methylureido group.

  Examples of the non-aromatic heterocyclic group include a piperidino group and a morpholino group.

  The molecular weight of the retardation developing agent is preferably 300 to 800.

  As the discotic compound, a triazine compound represented by the following general formula (I) is preferably used.

In the above general formula (I):
R ¹ independently represents an aromatic ring or a heterocyclic ring having a substituent in at least one of the ortho position, the meta position, and the para position.

X represents each independently a single bond or NR < ² >-. Here, each R ² independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, an alkenyl group, an aryl group, or a heterocyclic group.

The aromatic ring represented by R ¹ is preferably phenyl or naphthyl, and particularly preferably phenyl. The aromatic ring represented by R ¹ may have at least one substituent at any substitution position. Examples of the substituent include halogen atom, hydroxyl group, cyano group, nitro group, carboxyl group, alkyl group, alkenyl group, aryl group, alkoxy group, alkenyloxy group, aryloxy group, acyloxy group, alkoxycarbonyl group, Alkenyloxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, alkyl-substituted sulfamoyl group, alkenyl-substituted sulfamoyl group, aryl-substituted sulfamoyl group, sulfonamide group, carbamoyl, alkyl-substituted carbamoyl group, alkenyl-substituted carbamoyl group, aryl-substituted carbamoyl group, amide Groups, alkylthio groups, alkenylthio groups, arylthio groups and acyl groups.

The heterocyclic group represented by R ¹ preferably has aromaticity. The heterocycle having aromaticity is generally an unsaturated heterocycle, preferably a heterocycle having the largest number of double bonds. The heterocyclic ring is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and most preferably a 6-membered ring. The hetero atom of the heterocyclic ring is preferably a nitrogen atom, a sulfur atom or an oxygen atom, and particularly preferably a nitrogen atom. As the heterocyclic ring having aromaticity, a pyridine ring (2-pyridyl or 4-pyridyl as the heterocyclic group) is particularly preferable. The heterocyclic group may have a substituent. Examples of the substituent of the heterocyclic group are the same as the examples of the substituent of the aryl moiety.

  When X is a single bond, the heterocyclic group is preferably a heterocyclic group having a free valence on the nitrogen atom. The heterocyclic group having a free valence on the nitrogen atom is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and a 5-membered ring. Is most preferred. The heterocyclic group may have a plurality of nitrogen atoms. Further, the heterocyclic group may have a hetero atom other than the nitrogen atom (for example, O, S). Examples of heterocyclic groups having free valences on nitrogen atoms are shown below.

The alkyl group represented by R ² may be a cyclic alkyl group or a chain alkyl group, but a chain alkyl group is preferable, and a linear alkyl group is more preferable than a branched chain alkyl group. preferable.

  The number of carbon atoms in the alkyl group is preferably 1-30, more preferably 1-20, further preferably 1-10, still more preferably 1-8, and 1-6. Most preferred. The alkyl group may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (for example, methoxy group, ethoxy group) and an acyloxy group (for example, acryloyloxy group, methacryloyloxy group).

The alkenyl group represented by R ² may be a cyclic alkenyl group or a chain alkenyl group, but preferably represents a chain alkenyl group, and is a straight chain alkenyl group rather than a branched chain alkenyl group. More preferably it represents a group. The number of carbon atoms in the alkenyl group is preferably 2 to 30, more preferably 2 to 20, still more preferably 2 to 10, still more preferably 2 to 8, 6 is most preferred. The alkenyl group may have a substituent. Examples of the substituent are the same as those of the alkyl group described above.

The aromatic ring group and heterocyclic group represented by R ² are the same as the aromatic ring and heterocyclic ring represented by R ¹ , and the preferred range is also the same. The aromatic ring group and the heterocyclic group may further have a substituent, and examples of the substituent are the same as those of the aromatic ring and heterocyclic ring of R ¹ .

  As the discotic compound, a triphenylene compound represented by the following general formula (II) can also be preferably used.

In the general formula (II), R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom or a substituent.

The substituent represented by each of R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ is an alkyl group (preferably having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and particularly preferably carbon number). 1-20 alkyl groups, such as methyl, ethyl, isopropyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc. ), An alkenyl group (preferably an alkenyl group having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, particularly preferably 2 to 20 carbon atoms, such as a vinyl group, an allyl group, 2- Butenyl group, 3-pentenyl group and the like), alkynyl group (preferably 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, particularly preferably 2 carbon atoms). -20 alkynyl group, for example, propargyl group, 3-pentynyl group, etc., aryl group (preferably 6-30 carbon atoms, more preferably 6-20 carbon atoms, particularly preferably 6-6 carbon atoms). 12 aryl groups, for example, phenyl group, p-methylphenyl group, naphthyl group, etc., substituted or unsubstituted amino group (preferably having 0 to 40 carbon atoms, more preferably 0 to 30 carbon atoms). And particularly preferably an amino group having 0 to 20 carbon atoms, such as an unsubstituted amino group, a methylamino group, a dimethylamino group, a diethylamino group, and an anilino group).
An alkoxy group (preferably an alkoxy group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, and a butoxy group). Aryloxy group (preferably an aryloxy group having 6 to 40 carbon atoms, more preferably 6 to 30 carbon atoms, particularly preferably 6 to 20 carbon atoms, and examples thereof include a phenyloxy group and a 2-naphthyloxy group. An acyl group (preferably an acyl group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and particularly preferably 1 to 20 carbon atoms, such as an acetyl group, a benzoyl group, a formyl group, and a pivaloyl group. Etc.), an alkoxycarbonyl group (preferably having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, and particularly preferably carbon number) To 20 alkoxy groups such as methoxycarbonyl group and ethoxycarbonyl group), aryloxycarbonyl groups (preferably having 7 to 40 carbon atoms, more preferably having 7 to 30 carbon atoms, and particularly preferably carbon atoms). An aryloxycarbonyl group having 7 to 20 carbon atoms, such as a phenyloxycarbonyl group, and an acyloxy group (preferably having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, and particularly preferably 2 carbon atoms). To 20 acyloxy groups, such as an acetoxy group and a benzoyloxy group, and acylamino groups (preferably having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, and particularly preferably 2 to 20 carbon atoms). Acylamino groups such as acetylamino group, benzoylamino group, etc. And an alkoxycarbonylamino group (preferably an alkoxycarbonylamino group having 2 to 40 carbon atoms, more preferably 2 to 30 carbon atoms, particularly preferably 2 to 20 carbon atoms, such as a methoxycarbonylamino group) An aryloxycarbonylamino group (preferably 7 to 40 carbon atoms, more preferably 7 to 30 carbon atoms, particularly preferably 7 to 20 carbon atoms, such as phenyloxycarbonylamino group). Group), a sulfonylamino group (preferably a sulfonylamino group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, such as a methanesulfonylamino group, Benzenesulfonylamino group), sulfamoyl A group (preferably a sulfamoyl group having 0 to 40 carbon atoms, more preferably 0 to 30 carbon atoms, particularly preferably 0 to 20 carbon atoms, such as a sulfamoyl group, a methylsulfamoyl group, a dimethylsulfamoyl group, A phenylsulfamoyl group), a carbamoyl group (preferably a carbamoyl group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and particularly preferably 1 to 20 carbon atoms. Carbamoyl group, methylcarbamoyl group, diethylcarbamoyl group, phenylcarbamoyl group, etc.),
Alkylthio group (preferably having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, for example, methylthio group, ethylthio group, propylthio group, butylthio group, pentylthio group, hexylthio group , Heptylthio group, octylthio group and the like), arylthio group (preferably having 6 to 40 carbon atoms, more preferably 6 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, for example, phenylthio group). ), A sulfonyl group (preferably a sulfonyl group having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms, and examples thereof include a mesyl group and a tosyl group), sulfinyl Group (preferably having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 2 carbon atoms) Sulfinyl group, for example, methanesulfinyl group, benzenesulfinyl group, etc.), ureido group (preferably having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, particularly preferably 1 to 20 carbon atoms). A ureido group, for example, an unsubstituted ureido group, a methylureido group, a phenylureido group, and the like, a phosphoric acid amide group (preferably having 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and particularly preferably Is a phosphoric acid amide group having 1 to 20 carbon atoms, and examples thereof include a diethylphosphoric acid amide group and a phenylphosphoric acid amide group, a hydroxyl group, a mercapto group, a halogen atom (for example, a fluorine atom, a chlorine atom, bromine). Atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino , A hydrazino group, an imino group, a heterocyclic group (preferably a heterocyclic group having 1 to 30 carbon atoms, more preferably 1 to 12, for example, a heterocyclic ring having a hetero atom such as a nitrogen atom, an oxygen atom, a sulfur atom, etc. A imidazolyl group, a pyridyl group, a quinolyl group, a furyl group, a piperidyl group, a morpholino group, a benzoxazolyl group, a benzimidazolyl group, a benzthiazolyl group, a 1,3,5-triazyl group, etc.) A silyl group (preferably a silyl group having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms, and examples thereof include a trimethylsilyl group and a triphenylsilyl group. ) Is included. These substituents may be further substituted with these substituents. Moreover, when it has two or more substituents, they may be the same or different. If possible, they may be bonded to each other to form a ring.

The substituent represented by each of R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ is preferably an alkyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an alkylthio group or a halogen atom. is there.

  Although the specific example of a compound represented by general formula (II) below is given, it is not limited to this.

  The compound represented by the general formula (I) is, for example, a method described in JP-A No. 2003-344655, and the compound represented by the general formula (II) is, for example, a method described in JP-A-2005-134484. Can be synthesized by a known method.

  In the present invention, rod-like compounds having a linear molecular structure can be preferably used in addition to the above-mentioned discotic compounds. The linear molecular structure means that the molecular structure of the rod-like compound is linear in the most thermodynamically stable structure. The most thermodynamically stable structure can be obtained by crystal structure analysis or molecular orbital calculation. For example, molecular orbital calculation is performed using molecular orbital calculation software (for example, WinMOPAC2000, manufactured by Fujitsu Limited), and a molecular structure that minimizes the heat of formation of a compound can be obtained. The molecular structure being linear means that in the thermodynamically most stable structure obtained by calculation as described above, the angle of the main chain constituting the molecular structure is 140 degrees or more.

  As the rod-shaped compound having at least two aromatic rings, a compound represented by the following general formula (III) is preferable.

Formula (III): Ar ₁ -L ₁ -Ar ₂
In the general formula (III), Ar ₁ and Ar ₂ are each independently an aromatic group. In the present specification, the aromatic group includes an aryl group (aromatic hydrocarbon group), a substituted aryl group, an aromatic heterocyclic group, and a substituted aromatic heterocyclic group.

  An aryl group and a substituted aryl group are more preferable than an aromatic heterocyclic group and a substituted aromatic heterocyclic group. The heterocyclic ring of the aromatic heterocyclic group is generally unsaturated. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring. Aromatic heterocycles generally have the most double bonds. As a hetero atom, a nitrogen atom, an oxygen atom or a sulfur atom is preferable, and a nitrogen atom or a sulfur atom is more preferable.

  As the aromatic ring of the aromatic group, a benzene ring, a furan ring, a thiophene ring, a pyrrole ring, an oxazole ring, a thiazole ring, an imidazole ring, a triazole ring, a pyridine ring, a pyrimidine ring and a pyrazine ring are preferable, and a benzene ring is particularly preferable. .

  Examples of the substituent of the substituted aryl group and the substituted aromatic heterocyclic group include a halogen atom (F, Cl, Br, I), a hydroxyl group, a carboxyl group, a cyano group, an amino group, an alkylamino group (for example, methyl Amino group, ethylamino group, butylamino group, dimethylamino group), nitro group, sulfo group, carbamoyl group, alkylcarbamoyl group (for example, N-methylcarbamoyl group, N-ethylcarbamoyl group, N, N-) Dimethylcarbamoyl group), sulfamoyl group, alkylsulfamoyl group (eg, N-methylsulfamoyl group, N-ethylsulfamoyl group, N, N-dimethylsulfamoyl group), ureido Group, alkylureido group (for example, N-methylureido group, N, N-dimethylureido group, N, N, N′-trimethyl group) Each group of a ureido group), an alkyl group (for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, heptyl group, octyl group, isopropyl group, s-butyl group, tert-amyl group, cyclohexyl group, cyclopentyl) Group), alkenyl group (for example, vinyl group, allyl group, hexenyl group), alkynyl group (for example, ethynyl group, butynyl group), acyl group (for example, formyl group, acetyl group, butyryl group, Hexanoyl group, lauryl group), acyloxy group (for example, acetoxy group, butyryloxy group, hexanoyloxy group, lauryloxy group), alkoxy group (for example, methoxy group, ethoxy group, propoxy group, butoxy group) Pentyloxy group, heptyloxy group, octyloxy group), arylo Si group (for example, phenoxy group), alkoxycarbonyl group (for example, methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, butoxycarbonyl group, pentyloxycarbonyl group, heptyloxycarbonyl group), aryloxycarbonyl group ( For example, phenoxycarbonyl group), alkoxycarbonylamino group (for example, butoxycarbonylamino group, hexyloxycarbonylamino group), alkylthio group (for example, methylthio group, ethylthio group, propylthio group, butylthio group, pentylthio group, heptylthio group, octylthio group) Each group), arylthio group (for example, phenylthio group), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, propylsulfonyl group, butylsulfonyl group) Group, pentylsulfonyl group, heptylsulfonyl group, octylsulfonyl group), amide group (for example, acetamido group, butyramide group, hexylamide group, laurylamide group) and non-aromatic heterocyclic group ( For example, a morpholyl group and a pyrazinyl group) are included.

  Among these, preferable substituents include a halogen atom, a cyano group, a carboxyl group, a hydroxyl group, an amino group, an alkylamino group, an acyl group, an acyloxy group, an amide group, an alkoxycarbonyl group, an alkoxy group, an alkylthio group, and an alkyl group. Can be mentioned.

  The alkyl moiety of the alkylamino group, alkoxycarbonyl group, alkoxy group, and alkylthio group and the alkyl group may further have a substituent. Examples of the alkyl moiety and the substituent of the alkyl group include halogen atom, hydroxyl group, carboxyl group, cyano group, amino group, alkylamino group, nitro group, sulfo group, carbamoyl group, alkylcarbamoyl group, sulfamoyl group, alkylsulfur group. Famoyl group, ureido group, alkylureido group, alkenyl group, alkynyl group, acyl group, acyloxy group, alkoxy group, aryloxy group, alkoxycarbonyl group, aryloxycarbonyl group, alkoxycarbonylamino group, alkylthio group, arylthio group, An alkylsulfonyl group, an amide group and a non-aromatic heterocyclic group are included. As the substituent for the alkyl moiety and the alkyl group, a halogen atom, a hydroxyl group, an amino group, an alkylamino group, an acyl group, an acyloxy group, an acylamino group, an alkoxycarbonyl group, and an alkoxy group are preferable.

In the general formula (III), L ₁ is a divalent linking group selected from an alkylene group, an alkenylene group, an alkynylene group, —O—, —CO—, and a combination thereof.

  The alkylene group may have a cyclic structure. As the cyclic alkylene group, cyclohexylene is preferable, and 1,4-cyclohexylene is particularly preferable. As the chain alkylene group, a linear alkylene group is more preferable than a branched alkylene group.

  The number of carbon atoms of the alkylene group is preferably 1-20, more preferably 1-15, still more preferably 1-10, still more preferably 1-8, and most preferably 1-6. It is.

  The alkenylene group and the alkynylene group preferably have a chain structure rather than a cyclic structure, and more preferably have a linear structure rather than a branched chain structure.

  The alkenylene group and the alkynylene group preferably have 2 to 10 carbon atoms, more preferably 2 to 8, more preferably 2 to 6, still more preferably 2 to 4, and most preferably 2. (Vinylene group or ethynylene group).

  The arylene group preferably has 6 to 20 carbon atoms, more preferably 6 to 16, and still more preferably 6 to 12.

In the molecular structure of the general formula (III), the angle formed by Ar ₁ and Ar ₂ across L ₁ is preferably 140 degrees or more.

  As the rod-like compound, a compound represented by the following formula (IV) is more preferable.

Formula _{(IV): Ar 1 -L 2} -X-L 3 -Ar 2
In the general formula (IV), Ar ₁ and Ar ₂ are each independently an aromatic group. The definition and examples of the aromatic group are the same as those of Ar ₁ and Ar _{2 in} the general formula (III).

In General Formula (IV), L ₂ and L ₃ are each independently a divalent linking group selected from an alkylene group, —O—, —CO—, and a group consisting of a combination thereof.

  The alkylene group preferably has a chain structure rather than a cyclic structure, and more preferably has a linear structure rather than a branched chain structure.

  The alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, more preferably 1 to 6, still more preferably 1 to 4, and 1 or 2 (methylene group). Or an ethylene group) is most preferable.

L ₂ and L ₃ are particularly preferably —O—CO— or CO—O—.

  In the general formula (IV), X represents a 1,4-cyclohexylene group, a vinylene group or an ethynylene group.

  Specific examples of the compound represented by the general formula (III) or (IV) include compounds described in [Chemical Formula 1] to [Chemical Formula 11] of JP-A No. 2004-109657.

  Two or more rod-shaped compounds whose maximum absorption wavelength (λmax) is longer than 250 nm in the ultraviolet absorption spectrum of the solution may be used in combination.

  The rod-like compound can be synthesized with reference to methods described in literature. As literature, Mol. Cryst. Liq. Cryst. 53, 229 (1979), 89, 93 (1982), 145, 111 (1987), 170, 43 (1989), J. Am. Am. Chem. Soc. 113, p. 1349 (1991), p. 118, p. 5346 (1996), p. 92, p. 1582 (1970). Org. Chem. 40, 420 pages (1975), Tetrahedron, Vol. 48, No. 16, page 3437 (1992).

  Moreover, you may use the rod-shaped aromatic compound of the 11-11 pages of Unexamined-Japanese-Patent No. 2004-50516 as said retardation (retardation) developing agent.

  When the cellulose ester film is produced by a solvent cast method, the retardation (retardation) developing agent may be added to the dope. The addition may be performed at any timing. For example, a retardation developing agent may be dissolved in an organic solvent such as alcohol, methylene chloride, dioxolane, etc., and then added to the cellulose ester solution (dope). Or may be added directly into the dope composition.

  In addition, specific examples of preferable compounds of rod-like compounds other than those described in the above-mentioned publications are shown below.

  The specific examples (1) to (34), (41), and (42) have two asymmetric carbon atoms at the 1-position and the 4-position of the cyclohexane ring. However, since the specific examples (1), (4) to (34), (41), and (42) have a symmetrical meso type molecular structure, there are no optical isomers (optical activity), and geometric isomers (trans Type and cis type). The trans type (1-trans) and cis type (1-cis) of specific example (1) are shown below.

  As described above, the rod-like compound preferably has a linear molecular structure. Therefore, the trans type is preferable to the cis type.

  Specific examples (2) and (3) have optical isomers (a total of four isomers) in addition to geometric isomers. As for geometric isomers, the trans type is similarly preferable to the cis type. The optical isomer is not particularly superior or inferior, and may be D, L, or a racemate.

  In specific examples (43) to (45), the central vinylene bond includes a trans type and a cis type. For the same reason as above, the trans type is preferable to the cis type.

(Other additives)
The thermoplastic resin substrate according to the present invention can contain various compounds as additives depending on the purpose. For example, it contains retardation increasing agent, plasticizer, antioxidant, acid scavenger, light stabilizer, UV absorber, optical anisotropy control agent, matting agent, antistatic agent, release agent, etc. Can be made.

<Ultraviolet absorber>
The λ / 4 plate of the present invention can also contain an ultraviolet absorber. The ultraviolet absorber is intended to improve durability by absorbing ultraviolet rays of 400 nm or less, and in particular, the transmittance at a wavelength of 370 nm is preferably 10% or less, more preferably 5% or less, and further Preferably it is 2% or less.

  The ultraviolet absorber is not particularly limited, and examples thereof include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, triazine compounds, nickel complex compounds, inorganic powders, and the like. It is done.

  For example, 5-chloro-2- (3,5-di-sec-butyl-2-hydroxyphenyl) -2H-benzotriazole, (2-2H-benzotriazol-2-yl) -6- (linear and side Chain dodecyl) -4-methylphenol, 2-hydroxy-4-benzyloxybenzophenone, 2,4-benzyloxybenzophenone, etc., and tinuvin 109, tinuvin 171, tinuvin 234, tinuvin 326, tinuvin 327, tinuvin 328, There are tinuvins such as tinuvin 928, and these are all commercially available products from BASF Japan and can be preferably used.

  The UV absorbers preferably used in the present invention are benzotriazole UV absorbers, benzophenone UV absorbers, and triazine UV absorbers, particularly preferably benzotriazole UV absorbers and benzophenone UV absorbers. .

  In addition, a discotic compound such as a compound having a 1,3,5-triazine ring is also preferably used as the ultraviolet absorber.

  The cellulose ester solution in the present invention preferably contains two or more ultraviolet absorbers. As the UV absorber, a polymer UV absorber can also be preferably used, and in particular, a polymer type UV absorber described in JP-A-6-148430 is preferably used.

  The method of adding the UV absorber can be added to the dope after dissolving the UV absorber in an alcohol such as methanol, ethanol or butanol, an organic solvent such as methylene chloride, methyl acetate, acetone or dioxolane or a mixed solvent thereof. Or you may add directly in dope composition.

  For an inorganic powder that does not dissolve in an organic solvent, a dissolver or a sand mill is used in the organic solvent and cellulose ester to disperse and then added to the dope.

  The amount of UV absorber used is not uniform depending on the type of UV absorber, operating conditions, etc., but when the dry film thickness of the λ / 4 plate is 30 to 200 μm, it is 0.5 relative to the λ / 4 plate. -10 mass% is preferable, and 0.6-4 mass% is still more preferable.

<Antioxidant>
The antioxidant has a role of delaying or preventing the decomposition of the λ / 4 plate by, for example, the residual solvent amount of halogen in the λ / 4 plate, phosphoric acid of a phosphoric acid plasticizer, etc. It is preferably contained in the λ / 4 plate.

  As such an antioxidant, a hindered phenol compound is preferably used. For example, 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di- -T-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3 -(3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino)- 1,3,5-triazine, 2,2-thio-diethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octa Sil-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N, N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxy-hydrocinnamamide) 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-t-butyl-4-hydroxy Benzyl) -isocyanurate and the like.

  In particular, 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3 -(3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] is preferred. Further, for example, hydrazine-based metal deactivators such as N, N′-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine and tris (2,4-di- A phosphorus processing stabilizer such as t-butylphenyl) phosphite may be used in combination.

  The addition amount of these compounds is preferably 1 ppm to 1.0%, more preferably 10 to 1000 ppm in terms of mass ratio with respect to the total mass of the polymer (A) and the cellulose ester.

(Matting agent)
The thermoplastic resin substrate according to the present invention may be added with fine particles as a matting agent in order to prevent scratching or deterioration of transportability when the produced film is handled. preferable.

  As fine particles, examples of inorganic compounds include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, Examples thereof include magnesium silicate and calcium phosphate. Fine particles containing silicon are preferable in terms of low turbidity, and silicon dioxide is particularly preferable.

  The average primary particle diameter of the fine particles is preferably 5 to 400 nm, and more preferably 10 to 300 nm. These may be mainly contained as secondary aggregates having a particle size of 0.05 to 0.3 μm, and may be contained as primary particles without being aggregated if the particles have an average particle size of 80 to 400 nm. preferable. The content of these fine particles in the film is preferably 0.01 to 1% by mass, particularly preferably 0.05 to 0.5% by mass. In the case of a λ / 4 plate (retardation film) having a multilayer structure formed by the co-casting method, it is preferable to contain fine particles of this addition amount on the surface.

  Silicon dioxide fine particles are commercially available, for example, under the trade names Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (above Nippon Aerosil Co., Ltd.). it can.

  Zirconium oxide fine particles are commercially available, for example, under the trade names Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) and can be used.

  Examples of the resin include a silicone resin, a fluororesin, and an acrylic resin. Silicone resins are preferable, and those having a three-dimensional network structure are particularly preferable. For example, Tospearl 103, 105, 108, 120, 145, 3120, and 240 (manufactured by Toshiba Silicone Co., Ltd.) It is marketed by name and can be used.

  Among these, Aerosil 200V and Aerosil R972V are particularly preferably used because they have a large effect of reducing the friction coefficient while keeping the haze of the λ / 4 plate (retardation film) low. In the λ / 4 plate (retardation film) according to the present invention, it is preferable that the dynamic friction coefficient of at least one surface is 0.2 to 1.0.

<Manufacture of raw film>
In the present application, the film before oblique stretching is referred to as “raw film”. A long film stretched in an oblique direction so as to have an in-plane slow axis in an oblique direction with respect to the conveying direction of the long film is referred to as a “λ / 4 plate (retardation film)”.

  The raw film according to the present invention may be produced by either a solution casting method or a melt casting method. Hereinafter, the solution casting method will be described. As the film raw material, the above-described thermoplastic resin can be used. Hereinafter, as a typical example, a method for producing a λ / 4 plate (retardation film) containing cellulose ester as a main component will be described.

  The production of the raw film according to the present invention is a step of preparing a dope by dissolving an additive such as cellulose ester and the plasticizer in a solvent, and a step of casting the dope on a belt-shaped or drum-shaped metal support. , A process of drying the cast dope as a web, a process of peeling from the metal support, a process of stretching, a process of further drying, a process of further heat treating the obtained film if necessary, and a process of winding after cooling. Is called. The raw film according to the present invention preferably contains 60 to 95% by mass of a cellulose ester resin in the solid content.

  The process for preparing the dope will be described. The concentration of cellulose ester in the dope is preferably higher because the drying load after casting on the metal support can be reduced. However, if the concentration of cellulose ester is too high, the load during filtration increases and the filtration accuracy increases. Becomes worse. As a density | concentration which makes these compatible, 10-35 mass% is preferable, More preferably, it is 15-25 mass%.

  Organic solvents that dissolve cellulose esters and are useful for forming cellulose ester solutions or dopes include chlorinated organic solvents and non-chlorinated organic solvents. Methylene chloride (methylene chloride) can be mentioned as a chlorinated organic solvent, and it is suitable for dissolving cellulose esters, particularly cellulose triacetate. Due to recent environmental problems, the use of non-chlorine organic solvents has been studied. Examples of the non-chlorine organic solvent include methyl acetate, ethyl acetate, amyl acetate, acetone, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, cyclohexanone, ethyl formate, 2,2,2-trifluoroethanol, 2,2,3,3-hexafluoro-1-propanol, 1,3-difluoro-2-propanol, 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol, 1, Examples include 1,1,3,3,3-hexafluoro-2-propanol, 2,2,3,3,3-pentafluoro-1-propanol, nitroethane, and the like. When these organic solvents are used for cellulose triacetate, a dissolution method at room temperature can be used, but an insoluble material can be obtained by using a dissolution method such as a high-temperature dissolution method, a cooling dissolution method, or a high-pressure dissolution method. Can be reduced, which is preferable. Methylene chloride can be used for cellulose esters other than cellulose triacetate, but methyl acetate, ethyl acetate, and acetone are preferably used. Particularly preferred is methyl acetate. In the present invention, an organic solvent having good solubility with respect to the cellulose ester is referred to as a good solvent, and has a main effect on dissolution, and an organic solvent used in a large amount among them is a main (organic) solvent or a main ( Organic) solvent.

  The dope used in the present invention preferably contains 1 to 40% by mass of an alcohol having 1 to 4 carbon atoms in addition to the organic solvent. These are gelling solvents that make dope film (web) gel when the dope is cast on a metal support and the solvent starts to evaporate and the ratio of alcohol increases, making the web strong and easy to peel off from the metal support. When these ratios are small, there is also a role of promoting the dissolution of the cellulose ester of the non-chlorine organic solvent. Examples of the alcohol having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, and tert-butanol. Of these, ethanol is preferred because it has excellent dope stability, has a relatively low boiling point, and has good drying properties. These organic solvents are called poor solvents because they are not soluble in cellulose esters alone.

  It is preferable that the concentration of the cellulose ester in the dope is adjusted to 15 to 30% by mass and the dope viscosity is adjusted to a range of 100 to 500 Pa · s in order to obtain good film surface quality.

  A general method can be used as a dissolution method of the cellulose ester when preparing the dope described above. When heating and pressurization are combined, it is possible to heat above the boiling point at normal pressure. It is preferable to stir and dissolve while heating at a temperature that is equal to or higher than the boiling point of the solvent at normal pressure and that the solvent does not boil under pressure, in order to prevent the generation of massive undissolved materials called gels and mamaco. Moreover, after mixing a cellulose ester with a poor solvent and making it wet or swell, the method of adding a good solvent and melt | dissolving is also used preferably.

  The pressurization may be performed by a method of injecting an inert gas such as nitrogen gas or a method of increasing the vapor pressure of the solvent by heating. Heating is preferably performed from the outside. For example, a jacket type is preferable because temperature control is easy.

  The heating temperature with the addition of a solvent is preferably higher from the viewpoint of the solubility of the cellulose ester, but if the heating temperature is too high, the required pressure increases and the productivity deteriorates. A preferable heating temperature is 45 to 120 ° C, more preferably 60 to 110 ° C, and still more preferably 70 ° C to 105 ° C. The pressure is adjusted so that the solvent does not boil at the set temperature.

  Alternatively, a cooling dissolution method is also preferably used, whereby the cellulose ester can be dissolved in a solvent such as methyl acetate.

  Next, this cellulose ester solution is filtered using a suitable filter medium such as filter paper. As the filter medium, it is preferable that the absolute filtration accuracy is small in order to remove insoluble matters and the like. However, if the absolute filtration accuracy is too small, there is a problem that the filter medium is likely to be clogged. For this reason, a filter medium with an absolute filtration accuracy of 0.008 mm or less is preferable, a filter medium with 0.001 to 0.008 mm is more preferable, and a filter medium with 0.003 to 0.006 mm is still more preferable.

  There are no particular restrictions on the material of the filter medium, and ordinary filter media can be used. However, plastic filter media such as polypropylene and Teflon (registered trademark), and metal filter media such as stainless steel do not drop off fibers. preferable. It is preferable to remove and reduce impurities, particularly bright spot foreign matter, contained in the raw material cellulose ester by filtration.

A bright spot foreign material is when two polarizing plates are placed in a crossed Nicol state, a cellulose ester film is placed between them, light is applied from the side of one polarizing plate, and observed from the side of the other polarizing plate. It is a point (foreign matter) where light from the opposite side appears to leak, and the number of bright spots having a diameter of 0.01 mm or more is preferably 200 / cm ² or less. More preferably, it is 100 pieces / cm < ² > or less, More preferably, it is 50 pieces / m < ² > or less, More preferably, it is 0-10 pieces / cm < ² > or less. Further, it is preferable that the number of bright spots of 0.01 mm or less is small.

  The dope can be filtered by a normal method, but the method of filtering while heating at a temperature not lower than the boiling point of the solvent at normal pressure and in a range where the solvent does not boil under pressure is the filtration pressure before and after filtration. The increase in the difference (referred to as differential pressure) is small and preferable. A preferred temperature is 45 to 120 ° C, more preferably 45 to 70 ° C, and still more preferably 45 to 55 ° C.

  A smaller filtration pressure is preferred. The filtration pressure is preferably 1.6 MPa or less, more preferably 1.2 MPa or less, and further preferably 1.0 MPa or less.

  Here, the dope casting will be described.

  The metal support in the casting (casting) step preferably has a mirror-finished surface, and a stainless steel belt or a drum whose surface is plated with a casting is preferably used as the metal support. The cast width can be 1 to 4 m. The surface temperature of the metal support in the casting step is set to −50 ° C. to a temperature at which the solvent boils and does not foam. A higher temperature is preferable because the web can be dried faster, but if it is too high, the web may foam or the flatness may deteriorate. The preferable support temperature is appropriately determined at 0 to 100 ° C, and more preferably 5 to 30 ° C. Alternatively, it is also a preferable method that the web is gelled by cooling and peeled from the drum in a state containing a large amount of residual solvent. The method for controlling the temperature of the metal support is not particularly limited, and there are a method of blowing warm air or cold air, and a method of contacting hot water with the back side of the metal support. It is preferable to use warm water because heat transfer is performed efficiently, so that the time until the temperature of the metal support becomes constant is short. When using warm air, considering the temperature drop of the web due to the latent heat of vaporization of the solvent, while using warm air above the boiling point of the solvent, there may be cases where wind at a temperature higher than the target temperature is used while preventing foaming. . In particular, it is preferable to perform drying efficiently by changing the temperature of the support and the temperature of the drying air between casting and peeling.

  In order for the cellulose ester film to exhibit good flatness, the residual solvent amount when peeling the web from the metal support is preferably 10 to 150% by mass, more preferably 20 to 40% by mass or 60 to 130% by mass. Especially preferably, it is 20-30 mass% or 70-120 mass%. The temperature at the peeling position on the metal support is preferably −50 to 40 ° C., more preferably 10 to 40 ° C., and most preferably 15 to 30 ° C.

  In the present invention, the amount of residual solvent is defined by the following formula.

Residual solvent amount (% by mass) = {(MN) / N} × 100
Note that M is the mass of a sample collected during or after the production of the web or film, and N is the mass after heating M at 115 ° C. for 1 hour.

  Moreover, in the drying process of the cellulose ester film, the web is peeled off from the metal support, further dried, and dried until the residual solvent amount is 0.5% by mass or less.

  In the film drying process, generally, a roll drying method (a method in which a plurality of rolls arranged on the upper and lower sides are alternately passed through and dried) or a method of drying while transporting the web by a tenter method is adopted.

  When peeling from the metal support, the web is stretched in the longitudinal direction due to the peeling tension and the subsequent conveying tension. Therefore, in the present invention, when peeling the web from the casting support, the peeling and conveying tensions are reduced as much as possible. It is preferable to carry out in the state. Specifically, for example, it is effective to set it to 50 to 170 N / m or less. At that time, it is preferable to apply a cold air of 20 ° C. or less to fix the web rapidly.

  Next, the dried film is used as a raw film (raw film) according to the present invention, and is stretched at a desired angle by the above-described oblique stretching tenter according to the present invention to obtain a λ / 4 plate (retardation film). Can do.

<Manufacturing method of λ / 4 plate>
Various methods can be adopted as a method of manufacturing the λ / 4 plate of the present invention. For example, the method of the following aspect is preferable.

  As a preferred embodiment of the method for producing a λ / 4 plate of the present invention, a novel raw material that gives an in-plane slow axis at an arbitrary angle with respect to the extending direction of the film by obliquely stretching a long original film. It is a manufacturing method of a stretched film.

  Here, the “long” means a film having a length of at least about 5 times the width of the film, preferably a length of 10 times or more, specifically a roll shape. It has a length (film roll) that is wound around and stored or transported.

  In the manufacturing method of a long film, a film can be manufactured to desired arbitrary length by manufacturing a film continuously.

  In addition, the manufacturing method of a stretched film may be wound around the core once after film formation, and may be supplied to the oblique stretching step after forming the wound body, or the film may be formed without winding up the film after film formation. You may supply to the diagonal stretch process continuously from the process. It is preferable to continuously perform the film forming step and the oblique stretching step because the film forming conditions can be changed by feeding back the film thickness after stretching and the results of optical values to obtain a desired stretched film.

  In the method for producing a stretched film according to the present invention, a stretched film having a slow axis at an angle of more than 0 ° and less than 90 ° with respect to the extending direction of the film is produced. Here, the angle with respect to the extending direction of the film is an angle in the film plane. Since the slow axis is usually expressed in the stretching direction or a direction perpendicular to the stretching direction, in the production method according to the present invention, stretching is performed at an angle of more than 0 ° and less than 90 ° with respect to the extending direction of the film. Thus, a stretched film having such a slow axis can be produced.

  Angle formed by the extension direction of the film and the slow axis (the orientation angle θ can be arbitrarily set to a desired angle in the range of more than 0 ° and less than 90 °, more preferably 10 ° to 80 °. More preferably, the angle is 40 ° to 50 °, and a specific example is 45 °.

  The raw film can be obtained by a known method, for example, a solution cast molding method, an extrusion molding method, an inflation molding method, or the like. Among these, the solution cast molding method is excellent in the flatness and transparency of the film, and the extrusion molding method makes it easy to reduce Rt after oblique stretching, and the amount of residual volatile components is small, and the dimensional stability of the film is also excellent. Therefore, it is preferable. This raw film may be a single layer or a laminated film of two or more layers. The laminated film can be obtained by a known method such as a coextrusion molding method, a co-casting molding method, a film lamination method, or a coating method. Of these, the coextrusion molding method and the co-casting molding method are preferable.

  In the present invention, the thickness unevenness σm in the flow direction of a long original film subjected to stretching maintains a constant film take-up tension at the entrance of an oblique stretching tenter, which will be described later, and optical characteristics such as orientation angle and retardation. From the viewpoint of stabilizing the thickness, it is necessary to be less than 0.30 μm, preferably less than 0.25 μm, more preferably less than 0.20 μm.

  In order to keep the thickness unevenness σm in the flow direction of the long original film in the above range, in the case of the extrusion molding method, it is brought into close contact with a cooling drum as described in JP-A-2004-233604. This can be achieved by a method of keeping the molten thermoplastic resin in a stable state.

  Specifically, 1) A method in which a sheet-like thermoplastic resin extruded from a die is brought into close contact with a cooling drum under a pressure of 50 kPa or less when a raw film is produced by a melt extrusion method; When manufacturing the raw film by the extrusion method, the area from the die opening to the cooling drum that first adheres is covered with an enclosing member, and the distance from the enclosure member to the die opening or the first adhering cooling drum is 100 mm or less. Method: 3) Method of heating the temperature of the atmosphere within 10 mm to a specific temperature from the sheet-like thermoplastic resin extruded from the die opening when producing the raw film by the melt extrusion method; satisfying the relationship In this way, the sheet-like thermoplastic resin extruded from the die is taken into close contact with the cooling drum under a pressure of 50 kPa or less; 4) A raw film is produced by melt extrusion And the like; when, on the sheet-shaped thermoplastic resin extruded from the die opening, a method of speed difference between the take-up speed of the cooling drum to first contact blows following wind 0.2 m / s.

  Moreover, the film which has the gradient of the thickness of the width direction may be supplied as a raw film. The thickness gradient of the raw film so that the film thickness can be made the most uniform at the position where stretching has been completed is empirically determined by stretching films with varying thickness gradients experimentally. Can be requested. The gradient of the thickness of the raw film can be adjusted, for example, so that the thickness of the end portion on the thick side is about 0.5 to 3% thicker than the end portion on the thin side. it can.

  Although the width | variety of a raw film is not specifically limited, 500-4000 mm, Preferably it can be 1000-2000 mm. The total thickness of the film is not particularly limited, but is preferably in the range of 20 to 400 μm, preferably 20 to 200 μm.

  The preferred elastic modulus at the stretching temperature at the time of oblique stretching of the raw film is 0.01 to 5000 Mpa, more preferably expressed in terms of Young's modulus, from the viewpoint of the shrinkage rate during stretching and after stretching, the tension applied during stretching, and the like. 0.1 to 500 Mpa.

<Stretching with an oblique stretching tenter>
An oblique stretching apparatus (obliquely stretched tenter) is used for imparting orientation to the long original film subjected to stretching according to the present invention.

  The obliquely stretched tenter according to the present invention can freely set the orientation angle of the film by changing the rail pattern in various ways, and further orients the orientation axis of the film horizontally and evenly with high precision over the film width direction. It is preferable that the film stretching apparatus be capable of controlling the film thickness and retardation with high accuracy.

  FIG. 1 is a schematic view of a tenter capable of oblique stretching used in the method for producing a λ / 4 plate of the present invention. However, this is an example, and the present invention is not limited to this.

  The original film 1 whose direction is controlled by the guide roll 8-1 on the tenter entrance side is held at the position of the film holding start point 2-1 on the right side and the film holding start point 2-2 on the left side. The film is conveyed and stretched by the tenter 4 in the oblique direction indicated by the locus 3-1 of the right film holding means and the locus 3-2 of the left film holding means, and the right film holding end point 5- 1. Grasping is released by the film holding end point 5-2 on the left side, and conveyance is controlled by the guide roll 8-2 on the tenter outlet side, so that the obliquely stretched film 6 is formed. In the figure, the original fabric film is stretched obliquely at an angle (orientation angle θ) in the film stretching direction 9 with respect to the film feeding direction 7-1.

  In the present invention, the distance X1, X2 between the main shaft position of the guide roll 8-1 closest to the entrance of the obliquely stretched tenter and the gripping tool at the entrance of the obliquely stretched tenter needs to be 20 to 100 cm. By maintaining the distance, the plane of the film can be maintained when the film is gripped, and optical characteristics such as the longitudinal orientation angle θ and retardation can be stabilized. Preferably it is 20-60 cm, More preferably, it is 20-40 cm. Here, X1 is the distance between the main shaft position of the guide roll 8-1 and the gripping tool (clip gripping portion) at the film holding start point 2-1 on the right side, and X2 is the main shaft position of the guide roll 8-1. This is the distance of the gripping tool (clip gripping portion) at the film holding start point 2-2 on the left side.

  X1 and X2 may be either X1 = X2 or X1 ≠ X2, but preferably X1 = X2.

  In the present invention, X1 and X2 are preferably both in the range of 20 to 100 cm from the viewpoint of preventing variation in optical properties such as the orientation angle θ and retardation in the longitudinal direction of the stretched film.

  In order to set the distance between the main shaft position of the guide roll 8-1 closest to the entrance of the obliquely stretched tenter and the gripping tool of the obliquely stretched tenter to the above range, a mechanism capable of adjusting the position of the guide roll and the clip gripping part; The length of the gripping tool in the conveying direction is 1 to 5 inches (1 inch is 2.54 cm), and the diameter of the guide roll 8-1 closest to the entrance portion of the obliquely stretched tenter is 1 to 20 cm. And a mechanism that can further install a roll in the vicinity of the entrance of the obliquely stretched tenter.

  Production of the stretched film according to the present invention is performed using the tenter capable of oblique stretching, and this tenter is a long film that is moved in the advancing direction (middle point in the film width direction) in an oven heating environment. It is a device that widens in an oblique direction with respect to (direction). This tenter includes an oven, a pair of rails on the left and right on which a gripping tool for transporting the film travels, and a number of gripping tools that travel on the rails. Both ends of the film fed out from the film roll and sequentially supplied to the entrance portion of the tenter are gripped by a gripping tool, the film is guided into the oven, and the film is released from the gripping tool at the exit portion of the tenter. The film released from the gripping tool is wound around the core. Each of the pair of rails has an endless continuous track, and the gripping tool which has released the grip of the film at the exit portion of the tenter travels outside and is sequentially returned to the entrance portion.

  The rail shape of the tenter is asymmetrical on the left and right according to the orientation angle θ, the draw ratio, etc. given to the stretched film to be manufactured, and can be finely adjusted manually or automatically. In the present invention, a long thermoplastic resin film is stretched, and the orientation angle θ can be set to an arbitrary angle within a range of preferably 10 ° to 80 ° with respect to the winding direction after stretching. ing. In the present invention, the gripping tool of the tenter is configured to travel at a constant speed with a certain distance from the front and rear gripping tools.

  The traveling speed of the gripping tool can be selected as appropriate, but is usually 10 to 100 m / min. The difference in travel speed between the pair of left and right grippers is usually 1% or less, preferably 0.5% or less, more preferably 0.1% or less of the travel speed. This is because if there is a difference in the traveling speed between the left and right sides of the film at the exit of the stretching process, wrinkles and shifts will occur at the exit of the stretching process, so the speed difference between the right and left gripping tools is required to be substantially the same speed. Because.

  In general tenter devices, etc., there are speed irregularities that occur on the order of seconds or less depending on the period of the sprocket teeth that drive the chain, the frequency of the drive motor, etc. This does not correspond to the speed difference described in the invention.

Moreover, in the diagonally stretched tenter used in the present invention, it is preferable that the positions of the rail portions and the rail connecting portions can be freely set. Therefore, when an arbitrary entrance width and exit width are set, the stretch ratio corresponding to this is set. be able to. (The circled portion in FIG. 2 below is an example of a connecting portion.)
In the obliquely stretched tenter used in the present invention, a large bending rate is often required for the rail that regulates the trajectory of the gripping tool. In order to avoid interference between gripping tools due to sudden bending or local stress concentration, it is desirable that the trajectory of the gripping tool draws an arc at the bent portion.

  FIG. 2 shows a rail track (rail pattern) of a tenter used in the manufacturing method according to the present invention. The traveling direction DR1 at the tenter inlet of the unstretched film is different from the traveling direction DR2 at the tenter outlet side of the stretched film, and thus, even in a stretched film having a relatively large orientation angle θ, it is wide and uniform. Optical characteristics can be obtained. The feeding angle θi is an angle formed by the traveling direction D1 at the tenter entrance and the traveling direction DR2 on the tenter exit side of the stretched film. In the present invention, in order to produce a film having an orientation angle θ of preferably 10 ° to 80 ° as described above, the feeding angle θi is 10 ° <θi <60 °, preferably 15 ° <θi <50 °. Set by. By setting the feeding angle θi in the above range, the variation in the optical characteristics in the width direction of the obtained film becomes good (smaller).

  The long film is sequentially gripped at both ends (both sides) by the left and right grippers at the tenter entrance (position a), and travels as the grippers travel. The left and right grips CL, CR facing the direction of the film travel (DR1) at the tenter entrance (position a) run on the left-right asymmetric rail, preheating zone, stretching Pass through an oven with zones and cooling zones. Here, “substantially perpendicular” indicates that the angle formed by the straight line connecting the aforementioned gripping tools CL and CR and the film feeding direction DR1 is within 90 ± 1 °.

  The preheating zone refers to a section in which the vehicle travels while maintaining a constant interval between the gripping tools gripping both ends at the oven entrance. The stretching zone refers to an interval until the gap between the gripping tools gripping both ends starts to become constant again. In addition, the cooling zone refers to a section in which the temperature in the zone is set to be equal to or lower than the glass transition temperature Tg ° C. of the thermoplastic resin constituting the film during a period in which the interval between the gripping tools after the stretching zone becomes constant again. .

  The temperature of each zone is set to Tg to Tg + 30 ° C., the temperature of the stretching zone is set to Tg to Tg + 30 ° C., and the temperature of the cooling zone is set to Tg−30 to Tg ° C. with respect to the glass transition temperature Tg of the thermoplastic resin. It is preferable to do.

  In order to control the thickness unevenness in the width direction, a temperature difference may be given in the width direction in the stretching zone. In order to create a temperature difference in the width direction in the stretching zone, a method of adjusting the opening degree of the nozzle for sending warm air into the temperature-controlled room so as to make a difference in the width direction, or controlling the heating by arranging the heaters in the width direction is known. Can be used. The length of the preheating zone, the stretching zone and the cooling zone can be appropriately selected. The length of the preheating zone is usually 100 to 150% and the length of the fixed zone is usually 50 to 100% with respect to the length of the stretching zone. .

  Furthermore, wrinkles and cells of the stretched film can be used. As the load cell, a known tensile or compression type can be used. A load cell is a device that detects a load acting on an applied point by converting it into an electrical signal using a strain gauge attached to the strain generating body.

  The load cell is installed on the left and right bearings of the guide roll closest to the entrance of the obliquely stretched tenter, so that the force that the running film exerts on the roll, that is, the tension in the film traveling direction that is generated near both side edges of the film Are detected independently on the left and right. Note that a strain gauge may be directly attached to a support that constitutes the bearing portion of the roll, and the load, that is, the film tension may be detected based on the strain generated in the support. The relationship between the generated strain and the film tension is measured in advance and is known.

  The film tension detection device as described above is provided so that the tension in the vicinity of both side edges of the film in the guide roll closest to the entrance of the oblique stretching tenter is detected because the position and direction of the film is the same as that of the film stretching device. If there is a deviation with respect to the position and direction of the entrance, depending on the amount of deviation, there will be a difference in the tension in the vicinity of both side edges of the film in the guide roll closest to the entrance of the obliquely stretched tenter. This is because the degree of deviation is determined by detecting this tension difference.

  If the position and direction of the film are appropriate in relation to the position and direction of the inlet portion of the film stretching apparatus, the load acting on the roll will be roughly equal on the left and right, and if the positions are misaligned, There is a difference in film tension.

  In order to solve the occurrence of the shift, it is also preferable to maintain the support of the film at the time of stretching, lower the volatile content rate while shrinking after stretching in a state where the volatile content rate is 5% by volume or more. To maintain the support of the film means to grip both side edges without impairing the film property of the film. As for the volatile content, the state of 5% by volume or more may always be maintained in the stretching operation process, and the state of the volatile content is maintained at 5% by volume or more only in a part of the stretching operation process. May be. In the latter case, it is preferable that the entrance position is a starting point, and that the section of 50% or more of the entire stretching section and the volatile content rate are 12% by volume or more. In any case, it is preferable to have a volatile content of 12% by volume or more before stretching. Here, the volatile fraction (unit: volume%) represents the volume of the volatile component contained per unit volume of the film, and is a value obtained by dividing the volatile component volume by the film volume.

  The draw ratio R (W / W0) in the drawing step is preferably 1.3 to 3.0, more preferably 1.5 to 2.5. When the draw ratio is within this range, thickness unevenness in the width direction is reduced, which is preferable. In the stretching zone of the oblique stretching tenter, if the stretching temperature is made different in the width direction, the thickness unevenness in the width direction can be further improved. W0 represents the width of the film before stretching, and W represents the width of the film after stretching.

  The guide roll closest to the entrance of the tenter is a follower roll that guides the travel of the film, and is rotatably supported by bearings (not shown). A known material can be used for the roll, but it is preferable to reduce the weight by applying a ceramic coat to prevent the film from being damaged or by applying chrome plating to a light metal such as aluminum. . This roll is provided in order to stabilize the track when the film travels.

  Moreover, it is preferable that one of the rolls on the upstream side of the roll is nipped by pressing the rubber roll. This is because such a nip roll can suppress fluctuations in the drawing tension in the film flow direction.

  A pair of bearing portions at both ends (left and right) of the guide roll closest to the entrance of the tenter are provided with a first tension detecting device and a second film tension detecting device for detecting the tension generated in the film in the roll. It has been.

  Therefore, if the film position and angle are adjusted appropriately so that the difference in film tension between the left and right sides of the guide roll closest to the entrance of the oblique stretching tenter is equal, gripping by the gripping tool at the entrance of the film stretching apparatus is stable. In addition, the occurrence of obstacles such as removal of the gripping tool can be reduced, and the physical properties in the width direction of the film after oblique stretching by the film stretching apparatus can be stabilized.

  In order to cope with fine adjustment of the orientation angle and product variations, it is necessary to adjust the angle formed by the film traveling direction at the entrance of the oblique stretching tenter and the film traveling direction at the exit of the oblique stretching tenter. In that case, it is preferable from a viewpoint of productivity or a yield to perform film forming and diagonal stretch continuously. When the film forming process, the oblique stretching process, and the winding process are successively performed, it is preferable that the film traveling direction in the film forming process and the winding process coincide with each other in that the width of the process can be reduced. For such a process, in order to change the film transport direction in order to guide the formed film to the oblique stretching tenter inlet and / or to return the film exiting from the oblique stretching tenter outlet to the winder direction. A method for changing the film transport direction is required. As a device for changing the film transport direction, a known method such as an air flow roll can be used. It is preferable that the apparatus (winder apparatus, accumulator apparatus, drive apparatus, etc.) after the obliquely extending tenter exit is slidable in the lateral direction.

  FIGS. 3 and 4 show manufacturing patterns of the oblique stretching according to the various inventions described above.

  In the drawing, a film feeding device 10, a transport direction changing device 11, a winding device 12, and a film forming device 13 are shown.

  The film feeding device 10 is slidable and pivotable so that the film can be fed at a predetermined angle with respect to the obliquely stretched tenter entrance, or the film feeding device 10 is slidable, and the transport direction changing device 11, it is preferable that the film can be sent out to the entrance of the obliquely stretched tenter. By configuring the film feeding device and the transport direction changing device as described above, it becomes possible to further narrow the width of the entire manufacturing apparatus, and to finely control the film feeding position and angle, It becomes possible to obtain a stretched film with small variations in film thickness and optical value. Further, by making the film feeding device and the transport direction changing device movable, it is possible to effectively prevent the left and right clips from being caught in the film.

  By forming the winding device 12 so that the film can be pulled at a predetermined angle with respect to the outlet of the obliquely stretched tenter, it is possible to finely control the film take-up position and angle, and there are variations in film thickness and optical value. A small stretched film can be obtained. Therefore, the generation of wrinkles in the film can be effectively prevented, and the winding property of the film is improved, so that the film can be wound up in a long length.

  In the present invention, the take-up tension T (N / m) of the film after stretching is 100 N / m <T <300 N / from the viewpoints of preventing sagging and wrinkling of the film and preventing variation in the orientation angle in the width direction. m, preferably 150 N / m <T <250 N / m.

  In the present invention, from the viewpoint of preventing variations in the optical characteristics in the width direction and the flow direction, it is preferable to control the fluctuation of the take-up tension T with an accuracy of less than ± 5%, preferably less than ± 3%.

  As a method for controlling the fluctuation of the take-up tension T within the above range, general PID control is performed so that the load applied to the first roll at the tenter outlet, that is, the film tension is measured and the value is kept constant. A method of controlling the rotation speed of the take-up roll by a method is mentioned. Examples of the method for measuring the load include a method in which a load cell is attached to a bearing portion of a roll and a load applied to the roll, that is, a film tension is measured. As the load cell, a known tensile type or compression type can be used.

  The stretched film is released from the tenter outlet after being gripped by the gripper, trimmed at both ends (both sides) of the film, and then wound around a winding core (winding roll) to wind the stretched film. It can be turned around.

  Moreover, you may trim the both ends of the film currently hold | gripped with the holding tool of a tenter before winding up to a winding roll as needed. In addition, before winding, for the purpose of preventing blocking between the films, the masking film may be overlapped and wound up at the same time, or at least one of the stretched films, preferably wound up with tape or the like attached to both ends. Also good. The masking film is not particularly limited as long as it can protect the film, and examples thereof include a polyethylene terephthalate film, a polyethylene film, and a polypropylene film.

  The stretched film obtained by the production method according to the present invention has an orientation angle θ that is inclined in a range of, for example, 10 ° to 80 ° with respect to the winding direction. The variation of the inner retardation Ro is 4 nm or less, and the variation of the orientation angle θ is 1.0 ° or less.

  The variation of the in-plane retardation Ro of the λ / 4 plate of the present invention is 4 nm or less, preferably 3 nm or less, at least 1300 mm in the width direction.

  By setting the variation of the in-plane retardation Ro within the above range, the display quality can be improved when used as a retardation film for a liquid crystal display device.

  The variation in the orientation angle θ of the stretched film according to the present invention is 1.0 ° or less, preferably 0.80 ° or less, at least 1300 mm in the width direction, from the viewpoint of preventing contrast reduction due to light leakage.

For the in-plane retardation Ro of the λ / 4 plate of the present invention, an optimum value is selected according to the design of the display device used. Incidentally, the Ro-plane slow axis direction of the refractive indices n _x and plane by a value obtained by multiplying the average thickness d of the film to the difference between the refractive index n _y in the direction perpendicular to the slow axis (Ro = (Nx-ny) * d).

  The average thickness of the λ / 4 plate of the present invention is preferably 20 to 80 μm, more preferably 30 to 60 μm, and particularly preferably 30 to 40 μm from the viewpoint of mechanical strength and the like.

  Moreover, since the thickness unevenness in the width direction affects the availability of winding, it is preferably 3 μm or less, and more preferably 2 μm or less.

  The production method of the λ / 4 plate of the present invention is a production method of an embodiment having a step of curving the conveyance direction while first contracting the raw film in the width direction and then contracting in the direction perpendicular to the stretching axis. Is also preferable.

(Surface processed layer)
The λ / 4 plate of the present invention is characterized in that a hard coat layer is provided on the surface thereof.

  In the present invention, functional layers such as an antistatic layer, a backcoat layer, an antireflection layer, a slippery layer, an adhesive layer, an antiglare layer, and a barrier layer can be provided as the surface treatment layer.

<Hard coat layer>
The λ / 4 plate of the present invention preferably has a hard coat layer on its surface. The hard coat layer is preferably either a clear hard coat layer or an antiglare hard coat layer.

  As an embodiment of the present invention, it is preferable that the hard coat layer is a hard coat layer formed using a resin containing an active energy ray-curable resin from the viewpoint of manifesting the effects of the present invention. Furthermore, it is preferable that the hard coat layer is formed using a coating solution containing an acrylate ester having three or four acryloyl groups.

  When the hard coat layer is formed using a coating solution, the amount of solvent contained in the coating solution is preferably less than 10% by mass. Moreover, it is preferable that the solvent which the said coating liquid contains is ethanol or methanol. On the other hand, it is also preferable that the coating liquid does not contain water and an organic solvent.

  The hard coat layer used in the present invention is provided on at least one surface of the λ / 4 plate. In the present invention, it is also preferable that an antireflection layer including at least a low refractive index layer is provided on the hard coat layer. In particular, in the case of in-vehicle car navigation, in order to further improve the visibility, it is preferable to provide an antireflection layer on the antiglare hard coat layer.

  When the hard coat layer used in the present invention is anti-glare, it has a fine uneven shape on the surface. The fine uneven shape is formed by containing fine particles in the hard coat layer, and is as follows. It can be formed by containing fine particles having an average particle size of 0.01 to 4 μm in the hard coat layer. Further, as will be described later, as the surface roughness of the outermost surface of the antireflection layer provided on the antiglare hard coat layer, the centerline average roughness (Ra) defined by JIS B 0601 is 0.08. It is preferable to adjust to a range of ˜0.5 μm.

  In the case of the clear hard coat layer, it is a clear hard coat layer having a center line average roughness (Ra) defined by JIS B 0601 of 0.001 to 0.1 μm, and Ra is 0.002 to 0.05 μm. It is preferable. The center line average roughness (Ra) is preferably measured by an optical interference type surface roughness measuring instrument, and can be measured, for example, using a non-contact surface fine shape measuring device WYKO NT-2000 manufactured by WYKO.

  As particles contained in the antiglare hard coat layer used in the present invention, for example, inorganic or organic fine particles are used.

  Examples of the inorganic fine particles include silicon oxide, titanium oxide, aluminum oxide, tin oxide, zinc oxide, calcium carbonate, barium sulfate, talc, kaolin, and calcium sulfate.

  The organic fine particles include polymethyl methacrylate methyl acrylate resin fine particles, acrylic styrene resin fine particles, polymethyl methacrylate resin fine particles, silicone resin fine particles, polystyrene resin fine particles, polycarbonate resin fine particles, benzoguanamine resin fine particles, and melamine resin. Examples thereof include fine particles, polyolefin resin fine particles, polyester resin fine particles, polyamide resin fine particles, polyimide resin fine particles, and polyfluoroethylene resin fine particles.

  In the present invention, silicon oxide fine particles or polystyrene resin fine particles are particularly preferable.

  The inorganic or organic fine particles described above are preferably used in addition to a coating composition containing a resin or the like used for producing an antiglare hard coat layer.

  In order to impart anti-glare properties to the anti-glare hard coat layer used in the present invention, the content of the inorganic or organic fine particles is set to 0.100 parts by mass with respect to 100 parts by mass of the resin for preparing the anti-glare hard coat layer. 1 mass part-30 mass parts are preferable, More preferably, it is mix | blending so that it may become 0.1 mass part-20 mass parts. In order to give a more preferable antiglare effect, it is preferable to use 1 part by mass to 15 parts by mass of fine particles having an average particle size of 0.1 μm to 1 μm with respect to 100 parts by mass of the resin for preparing the antiglare hard coat layer. . It is also preferable to use two or more kinds of fine particles having different average particle diameters.

The antiglare hard coat layer used in the present invention preferably contains an antistatic agent, and examples of the antistatic agent include Sn, Ti, In, Al, Zn, Si, Mg, Ba, Mo, A conductive material containing at least one element selected from the group consisting of W and V as a main component and having a volume resistivity of 10 ⁷ Ω · cm or less is preferable.

  Examples of the antistatic agent include metal oxides and composite oxides having the above elements.

Examples of metal oxides are preferably ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , In ₂ O ₃ , SiO ₂ , MgO, BaO, MoO ₂ , V ₂ O ₅ , or a composite oxide thereof. In particular, ZnO, In ₂ O ₃ , TiO ₂ and SnO ₂ are preferred. Examples of containing different atoms include, for example, addition of Al, In, etc. to ZnO, addition of Nb, Ta, etc. to TiO ₂ , and addition of Sb, Nb, halogen elements, etc. to SnO ₂ . Addition is effective. The amount of these different atoms added is preferably in the range of 0.01 to 25 mol%, particularly preferably in the range of 0.1 to 15 mol%.

In addition, the volume resistivity of these metal oxide powders having conductivity is 10 ⁷ Ω · cm or less, particularly 10 ⁵ Ω · cm or less.

  From the viewpoint of imparting sufficient durability and impact resistance, the film thickness of the clear hard coat layer or the antiglare hard coat layer is preferably in the range of 0.5 to 15 μm, more preferably 1.0 to 7 μm. .

(Active energy ray curable resin)
The hard coat layer used in the present invention preferably contains an active energy ray-curable resin that is cured by irradiation with active energy rays such as ultraviolet rays.

  The active energy ray-curable resin is a resin that is cured through a crosslinking reaction or the like by irradiation with active energy rays such as ultraviolet rays or electron beams. Typical examples of the active energy ray curable resin include an ultraviolet curable resin and an electron beam curable resin, but a resin that is cured by irradiation with an active energy ray other than an ultraviolet ray or an electron beam may be used.

  Examples of the ultraviolet curable resin include an ultraviolet curable acrylic urethane resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, and an ultraviolet curable epoxy resin. be able to.

  UV curable acrylic urethane resins generally include 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate (hereinafter referred to as methacrylates) in products obtained by reacting polyester polyols with isocyanate monomers or prepolymers. Only acrylates are displayed as such), and can be easily obtained by reacting an acrylate monomer having a hydroxyl group (hydroxyl group) such as 2-hydroxypropyl acrylate. For example, a mixture of 100 parts Unidic 17-806 (manufactured by DIC Corporation) and 1 part of Coronate L (manufactured by Nippon Polyurethane Corporation) described in JP-A-59-151110 is preferably used.

  The UV curable polyester acrylate resin can be easily obtained by reacting a monomer such as 2-hydroxyethyl acrylate, glycidyl acrylate, or acrylic acid with a hydroxyl group (hydroxyl group) or a carboxyl group at the end of the polyester. JP, 59-151112, A).

  The ultraviolet curable epoxy acrylate resin is obtained by reacting a terminal hydroxyl group (hydroxyl group) of an epoxy resin with a monomer such as acrylic acid, acrylic acid chloride, or glycidyl acrylate.

  Examples of ultraviolet curable polyol acrylate resins include ethylene glycol (meth) acrylate, polyethylene glycol di (meth) acrylate, glycerin tri (meth) acrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipenta. Examples include erythritol pentaacrylate, dipentaerythritol hexaacrylate, and alkyl-modified dipentaerythritol pentaacrylate.

  As examples of the ultraviolet curable epoxy acrylate resin and the ultraviolet curable epoxy resin, useful epoxy-based active energy ray reactive compounds are shown.

(A) Glycidyl ether of bisphenol A (this compound is obtained as a mixture having different degrees of polymerization by reaction of epichlorohydrin and bisphenol A)
(B) a compound having a glycidyl ether group by reacting epichlorohydrin, ethylene oxide and / or propylene oxide with a compound having two phenolic OHs such as bisphenol A (c) glycidyl ether of 4,4'-methylenebisphenol (D) Epoxy compound of phenol formaldehyde resin of novolak resin or resol resin (e) Compound having alicyclic epoxide, for example, bis (3,4-epoxycyclohexylmethyl) oxalate, bis (3,4-epoxycyclohexylmethyl) ) Adipate, bis (3,4-epoxy-6-cyclohexylmethyl) adipate, bis (3,4-epoxycyclohexylmethyl pimelate), 3,4-epoxycyclohexylmethyl-3,4-epoxycyclo Xanthcarboxylate, 3,4-epoxy-1-methylcyclohexylmethyl-3 ', 4'-epoxycyclohexanecarboxylate, 3,4-epoxy-1-methyl-cyclohexylmethyl-3', 4'-epoxy-1 ' -Methylcyclohexanecarboxylate, 3,4-epoxy-6-methyl-cyclohexylmethyl-3 ', 4'-epoxy-6'-methyl-1'-cyclohexanecarboxylate, 2- (3,4-epoxycyclohexyl-5 ', 5'-spiro-3 ", 4" -epoxy) cyclohexane-meta-dioxane (f) diglycidyl ethers of dibasic acids such as diglycidyl oxalate, diglycidyl adipate, diglycidyl tetrahydrophthalate, diglycidyl Hexahydrophthalate, diglycidylf (G) Diglycidyl ether of glycol, for example, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, copoly (ethylene glycol-propylene glycol) di Glycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether (h) Glycidyl ester of polymer acid, for example, polyglycidyl ester of polyacrylic acid, polyester diglycidyl ester (i) Polyhydric alcohol Glycidyl ethers such as glycerin triglycidyl ether, trimethylolpropane triglycidyl Ether, pentaerythritol diglycidyl ether, pentaerythritol triglycidyl ether, pentaerythritol tetraglycidyl ether, glucose triglycidyl ether (j) As the diglycidyl ether of 2-fluoroalkyl-1,2-diol, Similar to the compound examples given for the fluorine-containing epoxy compound of the fluorine-containing resin (k) As the fluorine-containing alkane-terminated diol glycidyl ether, the fluorine-containing epoxy compound of the fluorine-containing resin of the low refractive index substance can be exemplified. .

  The molecular weight of the said epoxy compound is 2000 or less as an average molecular weight, Preferably it is 1000 or less.

  In the case where the above epoxy compound is cured with active energy rays, it is effective to use a compound having a polyfunctional epoxy group (h) or (i) in order to increase the hardness.

  The photopolymerization initiator or photosensitizer for cationically polymerizing an epoxy-based active energy ray-reactive compound is a compound capable of releasing a cationic polymerization initiator by irradiation with active energy rays, and particularly preferably a cation by irradiation. It is a group of double salts of onium salts that release Lewis acids capable of initiating polymerization.

  The active energy ray-reactive compound epoxy resin forms a polymerized, crosslinked structure or network structure not by radical polymerization but by cationic polymerization. Unlike radical polymerization, it is not affected by oxygen in the reaction system, and is therefore a preferred active energy ray reactive resin.

  The active energy ray-reactive epoxy resin useful in the present invention is polymerized by a photopolymerization initiator or a photosensitizer that releases a substance that initiates cationic polymerization upon irradiation with active energy rays. As the photopolymerization initiator, a group of double salts of onium salts that release a Lewis acid that initiates cationic polymerization by light irradiation is particularly preferable.

  A typical example is a compound represented by the following general formula (a).

General formula (a): [(R ¹ ) _a (R ² ) _b (R ³ ) _c (R ⁴ ) _d Z] ^{w +} [MeX _v ] ^w−
Wherein cation is onium, Z is S, Se, Te, P, As, Sb, Bi, O, halogen (eg, I, Br, Cl), or N = N (diazo), R ¹ , R ² , R ³ and R ⁴ are organic groups which may be the same or different. a, b, c, and d are each an integer of 0 to 3, and a + b + c + d is equal to the valence of Z. Me is a metal or metalloid which is a central atom of a halide complex, and B, P, As, Sb, Fe, Sn, Bi, Al, Ca, In, Ti, Zn, Sc, V, Cr, Mn, Co, etc. X is halogen, w is the net charge of the halogenated complex ion, and v is the number of halogen atoms in the halogenated complex ion.

Specific examples of the anion [MeX _v ] ^w− of the general formula (a) include tetrafluoroborate (BF ₄ ⁻ ), tetrafluorophosphate (PF ₄ ⁻ ), tetrafluoroantimonate (SbF ₄ ⁻ ), tetra Examples thereof include fluoroarsenate (AsF ₄ ⁻ ) and tetrachloroantimonate (SbCl ₄ ⁻ ).

Other anions include perchlorate ion (ClO ₄ ⁻ ), trifluoromethyl sulfite ion (CF ₃ SO ₃ ⁻ ), fluorosulfonate ion (FSO ₃ ⁻ ), toluenesulfonate ion, and trinitrobenzene acid anion. An ion etc. can be mentioned.

  Among these onium salts, it is particularly effective to use an aromatic onium salt as a cationic polymerization initiator. Among them, aromatic halonium salts described in JP-A Nos. 50-151996 and 50-158680 are particularly useful. VIA group aromatic onium salts described in Kaikai 50-151997, 52-30899, 59-55420, 55-125105, JP-A-56-8428, 56-149402, Preference is given to oxosulfoxonium salts described in 57-192429 and the like, aromatic diazonium salts described in JP-B-49-17040, thiopyridium salts described in US Pat. No. 4,139,655 and the like. Moreover, an aluminum complex, a photodegradable silicon compound type | system | group polymerization initiator, etc. can be mentioned. The cationic polymerization initiator can be used in combination with a photosensitizer such as benzophenone, benzoin isopropyl ether, or thioxanthone.

  In the case of an active energy ray-reactive compound having an epoxy acrylate group, a photosensitizer such as n-butylamine, triethylamine, or tri-n-butylphosphine can be used. The photosensitizer and photoinitiator used for the active energy ray-reactive compound are sufficient to initiate the photoreaction at 0.1 to 15 parts by mass with respect to 100 parts by mass of the ultraviolet-reactive compound, and preferably Is 1 to 10 parts by mass. The sensitizer preferably has an absorption maximum from the near ultraviolet region to the visible light region.

  In the active energy ray-curable resin composition useful in the present invention, the polymerization initiator is generally used in an amount of 0.1 to 15 parts by mass with respect to 100 parts by mass of the active energy ray-curable epoxy resin (prepolymer). More preferably, addition in the range of 1 to 10 parts by mass is preferable.

  An epoxy resin can be used in combination with the urethane acrylate type resin, polyether acrylate type resin, or the like. In this case, it is preferable to use an active energy ray radical polymerization initiator and an active energy ray cationic polymerization initiator in combination.

  Moreover, an oxetane compound can also be used for the hard-coat layer used for this invention. The oxetane compound used is a compound having a three-membered oxetane ring containing oxygen or sulfur. Among them, a compound having an oxetane ring containing oxygen is preferable. The oxetane ring may be substituted with a halogen atom, a haloalkyl group, an arylalkyl group, an alkoxyl group, an allyloxy group, or an acetoxy group. Specifically, 3,3-bis (chloromethyl) oxetane, 3,3-bis (iodomethyl) oxetane, 3,3-bis (methoxymethyl) oxetane, 3,3-bis (phenoxymethyl) oxetane, 3-methyl -3 chloromethyloxetane, 3,3-bis (acetoxymethyl) oxetane, 3,3-bis (fluoromethyl) oxetane, 3,3-bis (bromomethyl) oxetane, 3,3-dimethyloxetane and the like. In the present invention, any of a monomer, an oligomer and a polymer may be used.

  As an embodiment of the present invention, it is preferable that the hard coat layer is a hard coat layer formed using a resin containing an active energy ray-curable resin from the viewpoint of manifesting the effects of the present invention. Furthermore, it is preferable that the hard coat layer is formed using a coating solution containing an acrylate ester having three or four acryloyl groups.

  When the hard coat layer used in the present invention contains an active energy ray-curable resin, the active energy ray irradiation method includes an antiglare hard coat layer and an antireflection layer (medium to high refractive index layer) on a support. In addition, the active energy ray may be irradiated after the coating of the low refractive index layer or the like, but the active energy ray is preferably irradiated when the hard coat layer is coated.

The active energy ray used in the present invention can be used without limitation as long as it is an energy source that activates a compound such as ultraviolet ray, electron beam, γ ray, etc., but ultraviolet ray and electron beam are preferable, especially easy handling and high energy. UV rays are preferred in that they can be easily obtained. As the ultraviolet light source for photopolymerizing the ultraviolet reactive compound, any light source that generates ultraviolet light can be used. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used. An ArF excimer laser, a KrF excimer laser, an excimer lamp, synchrotron radiation, or the like can also be used. The irradiation conditions vary depending on individual lamps, but the amount of light irradiated is preferably 20 mJ / cm ² or more, more preferably, a 50~10000mJ / cm ^2, particularly preferably 50~2000mJ / cm ^2.

  The ultraviolet irradiation may be performed every time one layer is provided for each of a plurality of layers (medium refractive index layer, high refractive index layer, low refractive index layer) constituting the hard coat layer and the antireflection layer described later. The film may be irradiated after lamination. Or you may irradiate combining these. From the viewpoint of productivity, it is preferable to irradiate ultraviolet rays after laminating multiple layers.

  Moreover, an electron beam can be used similarly. As an electron beam, 50 to 1000 keV, preferably 100 to 100, emitted from various electron beam accelerators such as a cockroft Walton type, a bandegraph type, a resonance transformation type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type. An electron beam having an energy of 300 keV can be given.

  In order to initiate the photopolymerization or photocrosslinking reaction of the active energy ray-reactive compound used in the present invention, the active energy ray-reactive compound alone is initiated, but the polymerization induction period is long or the polymerization start is slow. Therefore, it is preferable to use a photosensitizer or a photoinitiator, which can accelerate the polymerization.

  When the hard coat layer used in the present invention contains an active energy ray-curable resin, a photoreaction initiator and a photosensitizer can be used during irradiation with active energy rays.

  Specific examples include acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and derivatives thereof. Moreover, when using a photoreactant for the synthesis | combination of an epoxy acrylate-type resin, sensitizers, such as n-butylamine, a triethylamine, tri-n-butylphosphine, can be used. The amount of the photoreaction initiator and / or photosensitizer contained in the ultraviolet curable resin composition excluding the solvent component that volatilizes after coating and drying is preferably 1 to 10% by mass, particularly preferably 2%. .5 to 6% by mass.

  Moreover, when using ultraviolet curable resin as active energy ray curable resin, you may include the ultraviolet absorber mentioned later in the ultraviolet curable resin composition to such an extent that the photocuring of the said ultraviolet curable resin is not prevented.

  In order to increase the heat resistance of the hard coat layer, an antioxidant that does not inhibit the photocuring reaction can be selected and used. Examples include hindered phenol derivatives, thiopropionic acid derivatives, phosphite derivatives, and the like. Specifically, for example, 4,4′-thiobis (6-tert-3-methylphenol), 4,4′-butylidenebis (6-tert-butyl-3-methylphenol), 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) mesitylene, di-octadecyl-4- Examples thereof include hydroxy-3,5-di-tert-butylbenzyl phosphate.

  Examples of the ultraviolet curable resin include ADEKA OPTMER KR, BY series KR-400, KR-410, KR-550, KR-566, KR-567, BY-320B (above, manufactured by ADEKA Corporation), Koeihard A-101-KK, A-101-WS, C-302, C-401-N, C-501, M-101, M-102, T-102, D-102, NS-101, FT -102Q8, MAG-1-P20, AG-106, M-101-C (manufactured by Guangei Chemical Industry Co., Ltd.), Seika Beam PHC2210 (S), PHCX-9 (K-3), PHC2213, DP- 10, DP-20, DP-30, P1000, P1100, P1200, P1300, P1400, P1500, P1600, SCR900 )), KRM7033, KRM7039, KRM7130, KRM7131, UVECRYL29201, UVECRYL29202 (above, Daicel UC Corporation), RC-5015, RC-5016, RC-5020, RC-5031, RC-5100, RC-5102 RC-5120, RC-5122, RC-5152, RC-5171, RC-5180, RC-5181 (manufactured by DIC Corporation), Aulex No. 340 clear (manufactured by China Paint Co., Ltd.), Sun Rad H-601 (manufactured by Sanyo Chemical Industries, Ltd.), SP-1509, SP-1507 (above, Showa Polymer Co., Ltd.), RCC-15C (Grace Japan Co., Ltd.), Aronix M-6100, M-8030, M-8060 (manufactured by Toagosei Co., Ltd.), or other commercially available products can be used as appropriate.

  The coating composition containing the active energy ray-curable resin preferably has a solid content concentration of 10 to 95% by mass, and an appropriate concentration is selected depending on the coating method.

  The hard coat layer and antireflection layer used in the present invention also preferably contain a surfactant, and the surfactant is preferably a silicone-based or fluorine-based surfactant.

  As the silicone-based surfactant, a nonionic surfactant having a hydrophobic group composed of dimethylpolysiloxane and a hydrophilic group composed of polyoxyalkylene is preferable.

  A nonionic surfactant is a generic term for a system surfactant that does not have a group capable of dissociating into ions in an aqueous solution. In addition to a hydrophobic group, a hydroxyl group (hydroxyl group) of a polyhydric alcohol is used as a hydrophilic group. It has an oxyalkylene chain (polyoxyethylene) or the like as a hydrophilic group. The hydrophilicity increases as the number of alcoholic hydroxyl groups (hydroxyl groups) increases and as the polyoxyalkylene chain (polyoxyethylene chain) becomes longer. The nonionic surfactant according to the present invention is characterized by having dimethylpolysiloxane as a hydrophobic group.

  When a nonionic surfactant composed of a dimethylpolysiloxane having a hydrophobic group and a polyoxyalkylene having a hydrophilic group is used, unevenness of the antiglare hard coat layer and the low refractive index layer and antifouling property of the film surface are improved. It is thought that the hydrophobic group made of polymethylsiloxane is oriented on the surface and forms a film surface that is not easily soiled. This effect cannot be obtained by using other surfactants.

  Specific examples of these nonionic surfactants include, for example, Nippon Unicar Co., Ltd., silicone surfactants SILWET L-77, L-720, L-7001, L-7002, L-7604, Y-7006, FZ-2101, FZ-2104, FZ-2105, FZ-2110, FZ-2118, FZ-2120, FZ-2122, FZ-2123, FZ-2130, FZ-2154, FZ-2161, FZ-2162, FZ- 2163, FZ-2164, FZ-2166, FZ-2191 and the like.

  Moreover, SUPERSILWET SS-2801, SS-2802, SS-2803, SS-2804, SS-2805, etc. are mentioned.

  In addition, as a preferable structure of the nonionic surfactant in which the hydrophobic group is composed of dimethylpolysiloxane and the hydrophilic group is composed of polyoxyalkylene, a dimethylpolysiloxane structure portion and a polyoxyalkylene chain are alternately and repeatedly bonded. It is preferably a linear block copolymer. Since the main chain skeleton has a long chain length and a linear structure, it is excellent. This is considered to be due to the fact that one activator molecule can be adsorbed on the surface of the silica fine particle so as to cover the surface of the silica fine particle at a plurality of locations by being a block copolymer in which hydrophilic groups and hydrophobic groups are alternately repeated.

  Specific examples thereof include, for example, silicone surfactants ABN SILWET FZ-2203, FZ-2207, FZ-2208 and the like manufactured by Nippon Unicar Co., Ltd.

  As the fluorine-based surfactant, a surfactant having a hydrophobic group having a perfluorocarbon chain can be used. As types, fluoroalkylcarboxylic acid, N-perfluorooctanesulfonyl glutamate disodium, sodium 3- (fluoroalkyloxy) -1-alkylsulfonate, 3- (ω-fluoroalkanoyl-N-ethylamino) -1- Sodium propanesulfonate, N- (3-perfluorooctanesulfonamido) propyl-N, N-dimethyl-N-carboxymethyleneammonium betaine, perfluoroalkylcarboxylic acid, perfluorooctanesulfonic acid diethanolamide, perfluoroalkylsulfonic acid Salt, N-propyl-N- (2-hydroxyethyl) perfluorooctanesulfonamide, perfluoroalkylsulfonamidopropyltrimethylammonium salt, perfluoroalkyl-N-ethyl Ruhonirugurishin salts, phosphoric acid bis (N- perfluorooctylsulfonyl -N- ethylamino ethyl) and the like. In the present invention, nonionic surfactants are preferred.

  These fluorosurfactants are commercially available under the trade names such as Megafac, F-Top, Surflon, Footagen, Unidyne, Florard, Zonyl and the like.

  A preferable addition amount is 0.01 to 3.0%, more preferably 0.02 to 1.0% per solid content contained in the coating liquid of the hard coat layer and the antireflection layer.

  Other surfactants can be used in combination. For example, anionic surfactants such as sulfonates, sulfates, phosphates, etc., and ethers having polyoxyethylene chain hydrophilic groups Type, ether ester type nonionic surfactants and the like may be used in combination.

  As the solvent for coating the hard coat layer according to the present invention, various solvents conventionally used for coating the hard coat layer can be used. In the present invention, a particularly preferred solvent is ethanol or methanol.

  The amount of solvent is preferably less than 10% by mass. More preferably, it is in the range of 5 to 8% by mass, or it is also preferred that no solvent is used and no solvent is used.

  When a monomer having 5 or more acrylic groups is used as the hard coat layer, streaks on the surface of the obliquely stretched λ / 4 plate (retardation film) are further emphasized. In addition, using a nonpolar solvent such as acetone, PGME (propylene glycol monomethyl ether), or ethyl acetate increases the residual stress in the oblique direction that remains on the obliquely stretched λ / 4 plate (retardation film) and To induce streaks. Alternatively, when a wet heat durability test is performed on a film provided with a coat layer, if a monomer having 5 or more acrylic groups or a nonpolar solvent as described above is used, the fluctuation value of the in-plane retardation Ro (maximum value−minimum) Value) is wide and larger than 10 nm. This significantly deteriorates the display quality when the produced film is provided in a display device.

  As a coating method of the hard coat layer composition coating solution, a known method such as a gravure coater, a spinner coater, a wire bar coater, a roll coater, a reverse coater, an extrusion coater, an air doctor coater, a spray coat, an ink jet method can be used. . The coating amount is suitably 5 to 30 μm, preferably 10 to 20 μm in terms of wet film thickness. The coating speed is preferably 10 to 200 m / min.

  The hard coat layer composition is preferably applied and dried, and then irradiated with an active energy ray such as an ultraviolet ray or an electron beam and cured, but the irradiation time of the active energy ray is preferably 0.5 seconds to 5 minutes. More preferably, it is 3 seconds to 2 minutes in view of the curing efficiency, work efficiency, etc. of the ultraviolet curable resin.

<Antireflection layer>
The antireflection layer used in the present invention may have a single-layer structure composed of only a low refractive index layer, but it is also preferable to provide a multilayer refractive index layer. Have a hard coat layer on a λ / 4 plate (retardation film) and laminate on the surface in consideration of the refractive index, film thickness, number of layers, layer order, etc. so that the reflectivity decreases due to optical interference it can. The antireflection layer is composed of a combination of a high refractive index layer having a higher refractive index than that of the support and a low refractive index layer having a lower refractive index than that of the support, and particularly preferably from three or more refractive index layers. An anti-reflection layer comprising three layers having different refractive indexes from the support side, a medium refractive index layer (having a higher refractive index than the support or the antiglare hard coat layer, and having a higher refractive index than the high refractive index layer). It is preferable that the layers are laminated in the order of (low layer) / high refractive index layer / low refractive index layer.

  Alternatively, an antireflection layer having a layer structure of four or more layers in which two or more high refractive index layers and two or more low refractive index layers are alternately laminated is also preferably used.

  Examples of preferred layer structures of the antireflection layer used in the present invention are shown below. Here, / indicates that the layers are arranged in layers.

(Λ / 4 plate) / Clear hard coat layer / Low refractive index layer (λ / 4 plate) / Clear hard coat layer / High refractive index layer / Low refractive index layer (λ / 4 plate) / Clear hard coat layer / Medium Refractive index layer / High refractive index layer / Low refractive index layer (λ / 4 plate) / Anti-glare hard coat layer / Low refractive index layer (λ / 4 plate) / Anti-glare hard coat layer / High refractive index layer / Low refractive index layer (λ / 4 plate) / Anti-glare hard coat layer / Medium refractive index layer / High refractive index layer / Low refractive index layer Low refractive index on the outermost surface so that dirt and fingerprints can be easily wiped off An antifouling layer can also be provided on the layer. As the antifouling layer, fluorine-containing organic compounds are preferably used.

As long as the reflectance can be reduced by optical interference, it is not limited to these layer configurations. In the above layer structure, an intermediate layer may be provided as appropriate. For example, an antistatic layer containing conductive polymer fine particles (for example, crosslinked cation fine particles) or metal oxide fine particles (for example, SnO ₂ , ITO) is preferable.

<Low refractive index layer>
In the low refractive index layer used in the present invention, the following hollow spherical silica-based fine particles are preferably used.

(Hollow spherical silica-based fine particles)
The hollow spherical fine particles are: (I) composite particles comprising porous particles and a coating layer provided on the surface of the porous particles, or (II) having a cavity inside, and the content is a solvent, gas or porous Cavity particles filled with a substance. Note that the low refractive index layer only needs to contain either (I) composite particles or (II) hollow particles, or both.

  The hollow particles are particles having cavities inside, and the cavities are surrounded by particle walls. The cavity is filled with contents such as a solvent, a gas, or a porous material used at the time of preparation. It is desirable that the average particle diameter of such hollow spherical fine particles is in the range of 5 to 300 nm, preferably 10 to 200 nm. The hollow spherical fine particles used are appropriately selected according to the thickness of the transparent film to be formed, and are in the range of 2/3 to 1/10 of the film thickness of the transparent film such as the low refractive index layer to be formed. Is desirable. These hollow spherical fine particles are preferably used in a state of being dispersed in an appropriate medium in order to form a low refractive index layer. As the dispersion medium, water, alcohol (for example, methanol, ethanol, isopropyl alcohol), ketone (for example, methyl ethyl ketone, methyl isobutyl ketone), and ketone alcohol (for example, diacetone alcohol) are preferable.

  The thickness of the coating layer of the composite particles or the thickness of the particle walls of the hollow particles is desirably in the range of 1 to 20 nm, preferably 2 to 15 nm. In the case of composite particles, if the thickness of the coating layer is less than 1 nm, the particles may not be completely covered, and it is easy to use a silicate monomer or oligomer having a low polymerization degree, which is a coating liquid component described later. The inside of the composite particles may enter and the internal porosity may decrease, and the low refractive index effect may not be sufficiently obtained. When the thickness of the coating layer exceeds 20 nm, the silicic acid monomer and oligomer do not enter the inside, but the porosity (pore volume) of the composite particles is lowered and the effect of low refractive index is sufficiently obtained. It may not be possible. In the case of hollow particles, if the particle wall thickness is less than 1 nm, the particle shape may not be maintained, and even if the thickness exceeds 20 nm, the effect of low refractive index may not be sufficiently exhibited. .

The coating layer of the composite particles or the particle wall of the hollow particles is preferably composed mainly of silica. Moreover, components other than silica may be contained, and specifically, Al ₂ O ₃ , B ₂ O ₃ , TiO ₂ , ZrO ₂ , SnO ₂ , CeO ₂ , P ₂ O ₃ , Sb ₂ O _3. , MoO ₃ , ZnO ₂ , WO _{3 and the} like. Examples of the porous particles constituting the composite particles include those made of silica, those made of silica and an inorganic compound other than silica, and those made of CaF ₂ , NaF, NaAlF ₆ , MgF, and the like. Among these, porous particles made of a composite oxide of silica and an inorganic compound other than silica are particularly preferable. Examples of inorganic compounds other than silica include Al ₂ O ₃ , B ₂ O ₃ , TiO ₂ , ZrO ₂ , SnO ₂ , CeO ₂ , P ₂ O ₃ , Sb ₂ O ₃ , MoO ₃ , ZnO ₂ and WO _3. 1 type or 2 types or more can be mentioned. In such porous particles, the molar ratio MO _X / SiO ₂ when the silica is expressed by SiO ₂ and the inorganic compound other than silica is expressed in terms of oxide (MO _X ) is 0.0001 to 1.0, Preferably it is in the range of 0.001 to 0.3. It is difficult to obtain a porous particle having a molar ratio MO _X / SiO ₂ of less than 0.0001. Even if it is obtained, a pore volume is small and particles having a low refractive index cannot be obtained. In addition, when the molar ratio MO _X / SiO _{2 of} the porous particles exceeds 1.0, the ratio of silica decreases, so that the pore volume increases and it is difficult to obtain a material having a lower refractive index. is there.

  The pore volume of such porous particles is desirably in the range of 0.1 to 1.5 ml / g, preferably 0.2 to 1.5 ml / g. If the pore volume is less than 0.1 ml / g, particles having a sufficiently reduced refractive index cannot be obtained. If the pore volume exceeds 1.5 ml / g, the strength of the fine particles is lowered, and the strength of the resulting coating may be lowered. is there.

  In addition, the pore volume of such porous particles can be determined by a mercury intrusion method. Examples of the contents of the hollow particles include a solvent, a gas, and a porous substance used at the time of preparing the particles. The solvent may contain an unreacted particle precursor used when preparing the hollow particles, the catalyst used, and the like. Examples of the porous substance include those composed of the compounds exemplified for the porous particles. These contents may be composed of a single component or may be a mixture of a plurality of components.

  As a method for producing such hollow spherical fine particles, for example, the method for preparing complex oxide colloidal particles disclosed in paragraphs [0010] to [0033] of JP-A-7-133105 is suitably employed. Specifically, when the composite particles are composed of silica and an inorganic compound other than silica, hollow spherical fine particles are produced from the following first to third steps.

First Step: Preparation of Porous Particle Precursor In the first step, an alkali aqueous solution of a silica raw material and an inorganic compound raw material other than silica is separately prepared in advance, or a silica raw material and an inorganic compound raw material other than silica are prepared in advance. A mixed aqueous solution is prepared, and this aqueous solution is gradually added to an aqueous alkaline solution having a pH of 10 or more while stirring according to the composite ratio of the target composite oxide to prepare a porous particle precursor.

  As the silica raw material, alkali metal, ammonium or organic base silicate is used. Sodium silicate (water glass) or potassium silicate is used as the alkali metal silicate. Examples of the organic base include quaternary ammonium salts such as tetraethylammonium salt, and amines such as monoethanolamine, diethanolamine, and triethanolamine. The ammonium silicate or organic base silicate includes an alkaline solution obtained by adding ammonia, a quaternary ammonium hydroxide, an amine compound, or the like to a silicate solution.

  In addition, alkali-soluble inorganic compounds are used as raw materials for inorganic compounds other than silica. Specifically, an oxo acid of an element selected from Al, B, Ti, Zr, Sn, Ce, P, Sb, Mo, Zn, W, etc., an alkali metal salt or alkaline earth metal salt of the oxo acid, ammonium And salts and quaternary ammonium salts. More specifically, sodium aluminate, sodium tetraborate, zirconyl ammonium carbonate, potassium antimonate, potassium stannate, sodium aluminosilicate, sodium molybdate, cerium ammonium nitrate, and sodium phosphate are suitable.

Although the pH value of the mixed aqueous solution changes simultaneously with the addition of these aqueous solutions, an operation for controlling the pH value within a predetermined range is not particularly required. The aqueous solution finally has a pH value determined by the type of inorganic oxide and the mixing ratio thereof. There is no restriction | limiting in particular in the addition rate of the aqueous solution at this time. Further, in the production of composite oxide particles, a dispersion of seed particles can be used as a starting material. The seed particles are not particularly limited, but inorganic oxides such as SiO ₂ , Al ₂ O ₃ , TiO ₂ or ZrO ₂ or fine particles of these composite oxides are used. Usually, these sols are used. Can do. Furthermore, the porous particle precursor dispersion obtained by the above production method may be used as a seed particle dispersion. When using the seed particle dispersion, the pH of the seed particle dispersion is adjusted to 10 or more, and then the aqueous solution of the compound is added to the alkaline aqueous solution with stirring. Also in this case, it is not always necessary to control the pH of the dispersion. When seed particles are used in this way, it is easy to control the particle size of the porous particles to be prepared, and particles with uniform particle sizes can be obtained.

  The silica raw material and the inorganic compound raw material described above have high solubility on the alkali side. However, when both are mixed in this highly soluble pH region, the solubility of oxo acid ions such as silicate ions and aluminate ions decreases, and these composites precipitate and grow into fine particles, or seed particles. It grows on the top and particle growth occurs. Therefore, it is not always necessary to perform pH control as in the conventional method for precipitation and growth of fine particles.

The composite ratio of silica and an inorganic compound other than silica in the first step is that the inorganic compound relative to silica is converted to an oxide (MO _X ), and the molar ratio of MO _X / SiO ₂ is 0.05 to 2.0, Preferably it is in the range of 0.2-2.0. Within this range, the pore volume of the porous particles increases as the proportion of silica decreases. However, even when the molar ratio exceeds 2.0, the pore volume of the porous particles hardly increases. On the other hand, when the molar ratio is less than 0.05, the pore volume becomes small. When preparing the hollow particles, the molar ratio of MO _X / SiO ₂ is preferably in the range of 0.25 to 2.0.

Second step: Removal of inorganic compound other than silica from porous particles In the second step, inorganic compounds other than silica (elements other than silicon and oxygen) are obtained from the porous particle precursor obtained in the first step. At least a portion is selectively removed. As a specific removal method, the inorganic compound in the porous particle precursor is dissolved and removed using a mineral acid or an organic acid, or is contacted with a cation exchange resin for ion exchange removal.

  The porous particle precursor obtained in the first step is a particle having a network structure in which silicon and an inorganic compound constituent element are bonded through oxygen. By removing the inorganic compound (elements other than silicon and oxygen) from the porous particle precursor in this way, porous particles having a larger porosity and a larger pore volume can be obtained. Further, if the amount of removing the inorganic oxide (elements other than silicon and oxygen) from the porous particle precursor is increased, the hollow particles can be prepared.

  In addition, prior to removing inorganic compounds other than silica from the porous particle precursor, fluorine-substituted, obtained by dealkalizing an alkali metal salt of silica into the porous particle precursor dispersion obtained in the first step. It is preferable to add a silicic acid solution containing an alkyl group-containing silane compound or a hydrolyzable organosilicon compound to form a silica protective film. The thickness of the silica protective film may be 0.5 to 15 nm. Even if the silica protective film is formed, the protective film in this step is porous and thin, so that it is possible to remove inorganic compounds other than silica described above from the porous particle precursor.

  By forming such a silica protective film, inorganic compounds other than silica described above can be removed from the porous particle precursor while maintaining the particle shape. Further, when forming the silica coating layer described later, the pores of the porous particles are not blocked by the coating layer, and therefore the silica coating layer described later is formed without reducing the pore volume. Can do. Note that when the amount of the inorganic compound to be removed is small, the particles are not broken, and thus it is not always necessary to form a protective film.

  Further, when preparing hollow particles, it is desirable to form this silica protective film. When preparing the hollow particles, the inorganic compound is removed to obtain a hollow particle precursor comprising a silica protective film, a solvent in the silica protective film, and an undissolved porous solid, and the hollow particles When a coating layer to be described later is formed on the precursor, the formed coating layer becomes a particle wall to form hollow particles.

The amount of the silica source added for forming the silica protective film is preferably small as long as the particle shape can be maintained. If the amount of the silica source is too large, the silica protective film becomes too thick, and it may be difficult to remove inorganic compounds other than silica from the porous particle precursor. The hydrolyzable organic silicon compound used for the silica protective film formed of the general formula _{R n Si (OR ') 4} -n [R, R': an alkyl group, an aryl group, a vinyl group, such as acrylic group An alkoxysilane represented by a hydrocarbon group, n = 0, 1, 2, or 3] can be used. In particular, tetraalkoxysilanes such as fluorine-substituted tetramethoxysilane, tetraethoxysilane, and tetraisopropoxysilane are preferably used.

  As an addition method, a solution obtained by adding a small amount of alkali or acid as a catalyst to a mixed solution of these alkoxysilane, pure water, and alcohol is added to the dispersion of the porous particles, and the alkoxysilane is hydrolyzed. The produced silicic acid polymer is deposited on the surface of the inorganic oxide particles. At this time, alkoxysilane, alcohol, and catalyst may be simultaneously added to the dispersion. As the alkali catalyst, ammonia, an alkali metal hydroxide, or an amine can be used. As the acid catalyst, various inorganic acids and organic acids can be used.

  When the dispersion medium of the porous particle precursor is water alone or the ratio of water to the organic solvent is high, it is possible to form a silica protective film using a silicic acid solution. When a silicic acid solution is used, a predetermined amount of the silicic acid solution is added to the dispersion, and at the same time an alkali is added to deposit the silicic acid solution on the surface of the porous particles. In addition, you may produce a silica protective film together using a silicic acid liquid and the said alkoxysilane.

Third step: Formation of silica coating layer In the third step, the porous particle dispersion prepared in the second step (in the case of hollow particles, the hollow particle precursor dispersion) contains a fluorine-substituted alkyl group-containing silane compound. By adding a hydrolyzable organosilicon compound or silicic acid solution, the surface of the particles is coated with a polymer such as a hydrolyzable organosilicon compound or silicic acid solution to form a silica coating layer.

The hydrolyzable organic silicon compound used for the silica coating layer formed, the above-mentioned such general formula _{R n Si (OR ') 4} -n [R, R': an alkyl group, an aryl group, a vinyl group, An alkoxysilane represented by a hydrocarbon group such as an acryl group, n = 0, 1, 2, or 3] can be used. In particular, tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, and tetraisopropoxysilane are preferably used.

  As an addition method, a solution obtained by adding a small amount of alkali or acid as a catalyst to a mixed solution of these alkoxysilanes, pure water, and alcohol is used as a dispersion of the porous particles (in the case of hollow particles, hollow particle precursor). In addition, the silicic acid polymer produced by hydrolyzing alkoxysilane is deposited on the surface of the porous particles (in the case of hollow particles, hollow particle precursors). At this time, alkoxysilane, alcohol, and catalyst may be simultaneously added to the dispersion. As the alkali catalyst, ammonia, an alkali metal hydroxide, or an amine can be used. As the acid catalyst, various inorganic acids and organic acids can be used.

  When the dispersion medium of the porous particles (cavity particle precursor in the case of hollow particles) is water alone or a mixed solvent with an organic solvent and the mixed solvent has a high ratio of water to the organic solvent, a silicate solution You may form a coating layer using. The silicic acid solution is an aqueous solution of a low silicic acid polymer obtained by dealkalizing an aqueous solution of an alkali metal silicate such as water glass by ion exchange treatment.

  The silicic acid solution is added to the dispersion of porous particles (in the case of hollow particles, hollow particle precursors), and at the same time, alkali is added to make the low-silicic acid polymer into porous particles (in the case of hollow particles, hollow particle precursors). ) Deposit on the surface. In addition, you may use a silicic acid liquid for the coating layer formation in combination with the said alkoxysilane. The addition amount of the organosilicon compound or silicic acid solution used for forming the coating layer only needs to be sufficient to cover the surface of the colloidal particles, and the silica coating layer finally obtained has a thickness of 1 to 20 nm. In such an amount, it is added in a dispersion of porous particles (in the case of hollow particles, hollow particle precursor) in a dispersion. When the silica protective film is formed, the organosilicon compound or the silicate solution is added in such an amount that the total thickness of the silica protective film and the silica coating layer is in the range of 1 to 20 nm.

  Next, the dispersion liquid of the particles on which the coating layer is formed is heat-treated. By the heat treatment, in the case of porous particles, the silica coating layer covering the surface of the porous particles is densified, and a dispersion of composite particles in which the porous particles are coated with the silica coating layer is obtained. In the case of the hollow particle precursor, the formed coating layer is densified to form hollow particle walls, and a dispersion of hollow particles having cavities filled with a solvent, gas, or porous solid content is obtained.

  The heat treatment temperature at this time is not particularly limited as long as it can close the fine pores of the silica coating layer, and is preferably in the range of 80 to 300 ° C. When the heat treatment temperature is less than 80 ° C., the fine pores of the silica coating layer may not be completely closed and densified, and the treatment time may take a long time. Further, when the heat treatment temperature exceeds 300 ° C. for a long time, fine particles may be formed, and the effect of low refractive index may not be obtained.

  The refractive index of the inorganic fine particles thus obtained is as low as less than 1.42. Such inorganic fine particles are presumed to have a low refractive index because the porosity inside the porous particles is maintained or the inside is hollow. The refractive index of the low refractive index layer used in the present invention is preferably 1.30 to 1.50, and more preferably 1.35 to 1.44.

In the present invention, the commercially available SiO ₂ fine particles can be used. Specific examples of commercially available particles include P-4 manufactured by Catalytic Chemical Industry Co., Ltd.

  The content (mass) of the hollow spherical silica-based fine particles A having an outer shell layer and having a porous or hollow interior in the low refractive index layer coating solution is preferably 10 to 80% by mass, and more preferably 20 to 60% by mass. % By mass.

(Tetraalkoxysilane compound or hydrolyzate thereof)
The low refractive index layer used in the present invention preferably contains a tetraalkoxysilane compound or a hydrolyzate thereof as a sol-gel material.

  As a material for the low refractive index layer used in the present invention, it is also preferable to use a silicon oxide having an organic group in addition to the inorganic silicon oxide. These are generally called sol-gel materials, but metal alcoholates, organoalkoxy metal compounds and hydrolysates thereof can be used. In particular, alkoxysilane, organoalkoxysilane and its hydrolyzate are preferable. Examples of these include tetraalkoxysilane (tetramethoxysilane, tetraethoxysilane, etc.), alkyltrialkoxysilane (methyltrimethoxysilane, ethyltrimethoxysilane, etc.), aryltrialkoxysilane (phenyltrimethoxysilane, etc.), dialkyl. Examples thereof include dialkoxysilane and diaryl dialkoxysilane. Tetraalkoxysilane and its hydrolyzate are particularly preferable.

  In addition, organoalkoxysilanes having various functional groups (vinyl trialkoxysilane, methylvinyl dialkoxysilane, γ-glycidyloxypropyltrialkoxysilane, γ-glycidyloxypropylmethyl dialkoxysilane, β- (3,4-epoxy) Dicyclohexyl) ethyltrialkoxysilane, γ-methacryloyloxypropyltrialkoxysilane, γ-aminopropyltrialkoxysilane, γ-mercaptopropyltrialkoxysilane, γ-chloropropyltrialkoxysilane, etc.), perfluoroalkyl group-containing silane compounds ( For example, it is also preferable to use (heptadecafluoro-1,1,2,2-tetradecyl) triethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, etc.). In particular, the use of a fluorine-containing silane compound is preferable in terms of lowering the refractive index of the layer and imparting water and oil repellency.

  When hydrolyzing the tetraalkoxysilane, it is preferable to mix the inorganic fine particles in order to increase the film strength.

  The low refractive index layer used in the present invention preferably contains the silicon oxide and the following silane coupling agent.

  Specific examples of the silane coupling agent include methyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxyethoxysilane, methyltriacetoxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane. Methoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, γ-chloropropyltriacetoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxy Propyltriethoxysilane, γ- (β-glycidyloxyethoxy) propyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, γ-acryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, Examples include N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane and β-cyanoethyltriethoxysilane.

  Examples of silane coupling agents having a disubstituted alkyl group with respect to silicon include dimethyldimethoxysilane, phenylmethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyldiethoxysilane, and γ-glycidyloxypropylmethyldiethoxysilane. Γ-glycidyloxypropylmethyldimethoxysilane, γ-glycidyloxypropylphenyldiethoxysilane, γ-chloropropylmethyldiethoxysilane, dimethyldiacetoxysilane, γ-acryloyloxypropylmethyldimethoxysilane, γ-acryloyloxypropylmethyldi Ethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, γ-methacryloyloxypropylmethyldiethoxysilane, γ-mercaptopropylmethyldimeth Shishiran, .gamma.-mercaptopropyl methyl diethoxy silane, .gamma.-aminopropyl methyl dimethoxy silane, .gamma.-aminopropyl methyl diethoxy silane, methyl vinyl dimethoxy silane, and methyl vinyl diethoxy silane.

  Among these, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, γ-acryloyloxypropyltrimethoxysilane and γ-methacryloyloxypropyltrimethoxysilane having a double bond in the molecule. Γ-acryloyloxypropylmethyldimethoxysilane, γ-acryloyloxypropylmethyldiethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, and γ-methacryloyloxypropylmethyldiethoxy having a disubstituted alkyl group with respect to silicon Silane, methylvinyldimethoxysilane and methylvinyldiethoxysilane are preferred, and γ-acryloyloxypropyltrimethoxysilane and γ-methacryloyloxyp Particularly preferred are propyltrimethoxysilane, γ-acryloyloxypropylmethyldimethoxysilane, γ-acryloyloxypropylmethyldiethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane and γ-methacryloyloxypropylmethyldiethoxysilane.

  Specific examples of the silane coupling agent include: Shin-Etsu Chemical Co., Ltd. KBM-303, KBM-403, KBM-402, KBM-403, KBM-1403, KBM-502, KBM-503, KBE-502, KBE- 503, KBM-603, KBE-603, KBM-903, KBE-903, KBE-9103, KBM-802, KBM-803 and the like.

  Two or more coupling agents may be used in combination. In addition to the silane coupling agents shown above, other silane coupling agents may be used. Other silane coupling agents include alkyl esters of orthosilicate (eg, methyl orthosilicate, ethyl orthosilicate, n-propyl orthosilicate, i-propyl orthosilicate, n-butyl orthosilicate, sec-butyl orthosilicate, orthosilicate). Acid t-butyl) and its hydrolyzate.

  A specific method of surface treatment with a coupling agent is shown below.

  These silane coupling agents are preferably hydrolyzed with a necessary amount of water in advance. When the silane coupling agent is hydrolyzed, the above-described silicon oxide particles and the surface of the silicon oxide having an organic group easily react, and a stronger film is formed. Moreover, you may add the hydrolyzed silane coupling agent in a coating liquid previously.

  The low refractive index layer can also contain a polymer in an amount of 5 to 50% by weight. The polymer has a function of adhering fine particles and maintaining the structure of a low refractive index layer including voids. The amount of the polymer used is adjusted so that the strength of the low refractive index layer can be maintained without filling the voids. The amount of the polymer is preferably 10 to 30% by mass of the total amount of the low refractive index layer. In order to adhere the fine particles with the polymer, (1) the polymer is bonded to the surface treatment agent of the fine particles, (2) the fine particles are used as a core, and a polymer shell is formed around the fine particles. It is preferable to use a polymer as the binder. The polymer to be bonded to the surface treating agent (1) is preferably the shell polymer (2) or the binder polymer (3). The polymer (2) is preferably formed around the fine particles by a polymerization reaction before preparing the coating solution for the low refractive index layer. The polymer (3) is preferably formed by adding a monomer to the coating solution for the low refractive index layer, and by polymerization reaction simultaneously with or after the coating of the low refractive index layer. It is preferable to carry out by combining two or all of the above (1) to (3), and to carry out by combining (1) and (3) or (1) to (3) all combinations. Particularly preferred. (1) Surface treatment, (2) shell, and (3) binder will be described sequentially.

(1) Surface treatment It is preferable that the fine particles (particularly inorganic fine particles) are subjected to a surface treatment to improve the affinity with the polymer. The surface treatment can be classified into physical surface treatment such as plasma discharge treatment and corona discharge treatment, and chemical surface treatment using a coupling agent. It is preferable to carry out by chemical surface treatment alone or a combination of physical surface treatment and chemical surface treatment. As the coupling agent, an organoalkoxy metal compound (eg, titanium coupling agent, silane coupling agent) is preferably used. When the fine particles are made of SiO _{2, the} surface treatment with the above-described silane coupling agent can be carried out particularly effectively.

  The surface treatment with the coupling agent can be carried out by adding the coupling agent to the dispersion of fine particles and leaving the dispersion at a temperature from room temperature to 60 ° C. for several hours to 10 days. In order to accelerate the surface treatment reaction, inorganic acids (for example, sulfuric acid, hydrochloric acid, nitric acid, chromic acid, hypochlorous acid, boric acid, orthosilicic acid, phosphoric acid, carbonic acid), organic acids (for example, acetic acid, polyacrylic acid, Benzenesulfonic acid, phenol, polyglutamic acid), or salts thereof (eg, metal salts, ammonium salts) may be added to the dispersion.

(2) Shell The polymer forming the shell is preferably a polymer having a saturated hydrocarbon as the main chain. A polymer containing a fluorine atom in the main chain or side chain is preferred, and a polymer containing a fluorine atom in the side chain is more preferred. Polyacrylic acid esters or polymethacrylic acid esters are preferred, and esters of fluorine-substituted alcohols with polyacrylic acid or polymethacrylic acid are most preferred. The refractive index of the shell polymer decreases as the content of fluorine atoms in the polymer increases. In order to lower the refractive index of the low refractive index layer, the shell polymer preferably contains 35 to 80% by mass of fluorine atoms, and more preferably contains 45 to 75% by mass of fluorine atoms. The polymer containing a fluorine atom is preferably synthesized by a polymerization reaction of an ethylenically unsaturated monomer containing a fluorine atom. Examples of ethylenically unsaturated monomers containing fluorine atoms include fluoroolefins (eg, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole), Examples thereof include esters of fluorinated vinyl ethers and fluorine-substituted alcohols with acrylic acid or methacrylic acid.

  The polymer forming the shell may be a copolymer composed of a repeating unit containing a fluorine atom and a repeating unit not containing a fluorine atom. The repeating unit containing no fluorine atom is preferably obtained by a polymerization reaction of an ethylenically unsaturated monomer containing no fluorine atom. Examples of ethylenically unsaturated monomers that do not contain fluorine atoms include olefins (eg, ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride), acrylic acid esters (eg, methyl acrylate, ethyl acrylate, acrylic acid 2- Ethyl hexyl), methacrylic acid esters (for example, methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate), styrene and its derivatives (for example, styrene, divinylbenzene, vinyltoluene, α-methylstyrene), vinyl ether ( For example, methyl vinyl ether), vinyl esters (for example, vinyl acetate, vinyl propionate, vinyl cinnamate), acrylamide (for example, N-tertbutylacrylamide, N-cyclohexylacrylic) Amides), methacrylamide and acrylonitrile.

  When the binder polymer (3) described later is used in combination, a crosslinkable functional group may be introduced into the shell polymer to chemically bond the shell polymer and the binder polymer by crosslinking. The shell polymer may have crystallinity. When the glass transition temperature (Tg) of the shell polymer is higher than the temperature at the time of forming the low refractive index layer, it is easy to maintain microvoids in the low refractive index layer. However, if Tg is higher than the temperature at which the low refractive index layer is formed, the fine particles are not fused, and the low refractive index layer may not be formed as a continuous layer (resulting in a decrease in strength). In that case, it is desirable to use a binder polymer (3) described later in combination, and form the low refractive index layer as a continuous layer with the binder polymer. By forming a polymer shell around the fine particles, core-shell fine particles are obtained. The core-shell fine particles preferably contain 5 to 90% by volume of a core composed of inorganic fine particles, and more preferably 15 to 80% by volume. Two or more kinds of core-shell fine particles may be used in combination. Further, inorganic fine particles having no shell and core-shell particles may be used in combination.

(3) Binder The binder polymer is preferably a polymer having a saturated hydrocarbon or polyether as the main chain, and more preferably a polymer having a saturated hydrocarbon as the main chain. The binder polymer is preferably crosslinked. The polymer having a saturated hydrocarbon as the main chain is preferably obtained by a polymerization reaction of an ethylenically unsaturated monomer. In order to obtain a crosslinked binder polymer, it is preferable to use a monomer having two or more ethylenically unsaturated groups. Examples of monomers having two or more ethylenically unsaturated groups include esters of polyhydric alcohol and (meth) acrylic acid (for example, ethylene glycol di (meth) acrylate, 1,4-dichlorohexane diacrylate, pentaerythritol). Tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, Pentaerythritol hexa (meth) acrylate, 1,2,3-cyclohexanetetramethacrylate, polyurethane polyacrylate, polyester polyacrylate), vinylbenzene and its derivatives For example, 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloyl ethyl ester, 1,4-divinylcyclohexanone), vinyl sulfone (eg, divinyl sulfone), acrylamide (eg, methylene bisacrylamide) and methacrylamide Can be mentioned. The polymer having a polyether as the main chain is preferably synthesized by a ring-opening polymerization reaction of a polyfunctional epoxy compound. Instead of or in addition to the monomer having two or more ethylenically unsaturated groups, a crosslinked structure may be introduced into the binder polymer by the reaction of a crosslinkable group. Examples of crosslinkable functional groups include isocyanate groups, epoxy groups, aziridine groups, oxazoline groups, aldehyde groups, carbonyl groups, hydrazine groups, carboxyl groups, methylol groups, and active methylene groups. Vinylsulfonic acid, acid anhydride, cyanoacrylate derivative, melamine, etherified methylol, ester and urethane can also be used as a monomer for introducing a crosslinked structure. A functional group that exhibits crosslinkability as a result of the decomposition reaction, such as a block isocyanate group, may be used. The cross-linking group is not limited to the above compound, and may be one that exhibits reactivity as a result of decomposition of the functional group. As the polymerization initiator used for the polymerization reaction and the crosslinking reaction of the binder polymer, a thermal polymerization initiator or a photopolymerization initiator is used, and the photopolymerization initiator is more preferable. Examples of photopolymerization initiators include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds , Fluoroamine compounds and aromatic sulfoniums. Examples of acetophenones include 2,2-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxydimethylphenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-morpholinopropiophenone and 2 -Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone. Examples of benzoins include benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether. Examples of benzophenones include benzophenone, 2,4-dichlorobenzophenone, 4,4-dichlorobenzophenone and p-chlorobenzophenone. Examples of phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

  The binder polymer is preferably formed by adding a monomer to the coating solution for the low refractive index layer, and at the same time as or after the coating of the low refractive index layer, by a polymerization reaction (further crosslinking reaction if necessary). Even if a small amount of polymer (for example, polyvinyl alcohol, polyoxyethylene, polymethyl methacrylate, polymethyl acrylate, diacetyl cellulose, triacetyl cellulose, nitrocellulose, polyester, alkyd resin) is added to the coating solution for the low refractive index layer Good.

  Further, even if the low refractive index layer used in the present invention is a low refractive index layer formed by crosslinking a fluorine-containing resin that is crosslinked by heat or ionizing radiation (hereinafter also referred to as “fluorine-containing resin before crosslinking”). Good.

  Preferred examples of the fluorine-containing resin before crosslinking include a fluorine-containing copolymer formed from a fluorine-containing vinyl monomer and a monomer for imparting a crosslinkable group. Specific examples of the fluorine-containing vinyl monomer unit include, for example, fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3 -Dioxoles, etc.), (meth) acrylic acid partial or fully fluorinated alkyl ester derivatives (for example, Biscoat 6FM (manufactured by Osaka Organic Chemicals) and M-2020 (manufactured by Daikin)), fully or partially fluorinated vinyl ethers, etc. Is mentioned. As monomers for imparting a crosslinkable group, glycidyl methacrylate, vinyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, vinyl glycidyl ether, and other vinyl monomers having a crosslinkable functional group in advance in the molecule. , Vinyl monomers having a carboxyl group, hydroxyl group, amino group, sulfonic acid group, etc. (for example, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, hydroxyalkyl vinyl ether, hydroxyalkyl allyl) Ether, etc.). In the latter case, it is possible to introduce a crosslinked structure by adding a compound having a group that reacts with a functional group in the polymer and one or more reactive groups after copolymerization. -147739. Examples of the crosslinkable group include acryloyl, methacryloyl, isocyanate, epoxy, aziridine, oxazoline, aldehyde, carbonyl, hydrazine, carboxyl, methylol, and active methylene group. When the fluorine-containing copolymer is crosslinked by heating with a crosslinking group that reacts by heating, or a combination of an ethylenically unsaturated group and a thermal radical generator or an epoxy group and a thermal acid generator, it is a thermosetting type. In the case of crosslinking by irradiation with light (preferably ultraviolet rays, electron beams, etc.) by a combination of an ethylenically unsaturated group and a photo radical generator, or an epoxy group and a photo acid generator, the ionizing radiation curable type is used.

  In addition to the above monomers, a fluorine-containing copolymer formed by using a monomer other than the fluorine-containing vinyl monomer and the monomer for imparting a crosslinkable group may be used as the fluorine-containing resin before crosslinking. The monomer that can be used in combination is not particularly limited. For example, olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic esters (methyl acrylate, methyl acrylate, ethyl acrylate, 2-acrylic acid 2- Ethyl hexyl), methacrylates (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, vinyl toluene, α-methylstyrene, etc.), vinyl ethers (methyl vinyl ether) Etc.), vinyl esters (vinyl acetate, vinyl propionate, vinyl cinnamate, etc.), acrylamides (N-tertbutylacrylamide, N-cyclohexylacrylamide, etc.), methacrylamides, Ronitoriru derivatives and the like. Moreover, it is also preferable to introduce a polyorganosiloxane skeleton or a perfluoropolyether skeleton into the fluorinated copolymer in order to impart slipperiness and antifouling properties. For example, polyorganosiloxane or perfluoropolyether having an acrylic group, methacrylic group, vinyl ether group, styryl group or the like at the terminal is polymerized with the above monomer, and polyorganosiloxane or perfluoro having a radical generating group at the terminal. It can be obtained by polymerization of the above monomer with a polyether, reaction of a polyorganosiloxane or perfluoropolyether having a functional group with a fluorine-containing copolymer, or the like.

  About the usage-amount of each said monomer used in order to form the fluorine-containing copolymer before bridge | crosslinking, a fluorine-containing vinyl monomer becomes like this. Preferably it is 20-70 mol%, More preferably, it is a ratio of 40-70 mol%. . The monomer for imparting a crosslinkable group is preferably 1 to 20 mol%, more preferably 5 to 20 mol%. Furthermore, the other monomer used together is preferably 10 to 70 mol%, more preferably 10 to 50 mol%.

  The fluorine-containing copolymer can be obtained by polymerizing these monomers in the presence of a radical polymerization initiator by means such as solution polymerization, bulk polymerization, emulsion polymerization, suspension polymerization.

  The fluorine-containing resin before crosslinking is commercially available and can be used. Examples of commercially available fluorine-containing resins before cross-linking include Cytop (Asahi Glass), Teflon (registered trademark) AF (DuPont), polyvinylidene fluoride, Lumiflon (Asahi Glass), Opstar (JSR), etc. Can be mentioned.

  The low refractive index layer containing a cross-linked fluororesin as a constituent component preferably has a dynamic friction coefficient in the range of 0.03 to 0.15 and a contact angle with water in the range of 90 to 120 degrees.

  The low refractive index layer used in the present invention is applied by dip coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating or extrusion coating (US Pat. No. 2,681,294). Can be formed. Two or more layers may be applied simultaneously. For the method of simultaneous application, US Pat. Nos. 2,761,791, 2,941,898, 3,508,947, 3,526,528 and Yuji Harasaki, Coating Engineering, page 253, It is described in Asakura Shoten (1973).

  The film thickness of the low refractive index layer used in the present invention is preferably 50 to 200 nm, and more preferably 60 to 150 nm.

<High refractive index layer and medium refractive index layer>
In the present invention, it is preferable to provide a high refractive index layer between the hard coat layer and the low refractive index layer in order to reduce the reflectance. Alternatively, it is more preferable to provide a middle refractive index layer between the docoat layer and the high refractive index layer. The refractive index of the high refractive index layer is preferably 1.55 to 2.30, and more preferably 1.57 to 2.20. The refractive index of the middle refractive index layer is adjusted to be an intermediate value between the refractive index of the support and the refractive index of the high refractive index layer. The refractive index of the middle refractive index layer is preferably 1.55-1.80. The thickness of the high refractive index layer and the middle refractive index layer is preferably 5 nm to 1 μm, more preferably 10 nm to 0.2 μm, and most preferably 30 nm to 100 nm. The haze of the high refractive index layer and the medium refractive index layer is preferably 5% or less, more preferably 3% or less, and most preferably 1% or less. The strength of the high refractive index layer and the medium refractive index layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher, with a pencil hardness of 1 kg.

  The refractive index formed by applying and drying a coating solution containing a monomer, oligomer or hydrolyzate of an organotitanium compound represented by the following general formula (9) in the high refractive index layer used in the present invention. A layer having a rate of 1.55 to 2.5 is preferred.

General formula (9): Ti (OR ₁ ) ₄
In the formula, R ₁ is preferably an aliphatic hydrocarbon group having 1 to 8 carbon atoms, preferably an aliphatic hydrocarbon group having 1 to 4 carbon atoms. Moreover, the monomer, oligomer, or hydrolyzate thereof of an organic titanium compound reacts like -Ti-O-Ti- when an alkoxide group is hydrolyzed to form a crosslinked structure, thereby forming a cured layer.

Examples of the monomer or oligomer of the organic titanium compound used in the present invention include Ti (OCH ₃ ) ₄ , Ti (OC ₂ H ₅ ) ₄ , Ti (On-C ₃ H ₇ ) ₄ , and Ti (Oi−). C ₃ H ₇ ) ₄ , Ti (On-C ₄ H ₉ ) ₄ , Ti (On-C ₃ H ₇ ) ₄ dimer to 10-mer, Ti (Oi-C ₃ H ₇ ) Preferred examples include ₄ to 10 mer of ₄ and 2 to 10 mer of Ti (On-C ₄ H ₉ ) ₄ . These can be used alone or in combination of two or more. Of these _{Ti (O-n-C 3} H 7) 4, Ti (O-i-C 3 H 7) 4, Ti (O-n-C 4 H 9) 4, Ti (O-n-C 3 H 7 ) ₄ 2-10 mer, 2-10 mer _{Ti (O-n-C 4} H 9) 4 are particularly preferred.

  Among the coating solutions for the high refractive index layer used in the present invention, it is preferable to add the organic titanium compound to a solution in which water and an organic solvent described later are sequentially added. When water is added later, hydrolysis / polymerization does not proceed uniformly, and white turbidity occurs or film strength decreases. After the water and the organic solvent are added, it is preferable that they are stirred and mixed and dissolved in order to mix well.

  Further, as another method, it is also a preferred embodiment that an organic titanium compound and an organic solvent are mixed and this mixed solution is added to the mixed and stirred solution of water and the organic solvent.

  Moreover, it is preferable that the quantity of water is the range of 0.25-3 mol with respect to 1 mol of organic titanium compounds from viewpoints, such as a hydrolysis and progress of superposition | polymerization. Therefore, the amount of water needs to be adjusted within the above range.

  Moreover, it is preferable that the content rate of water is less than 10 mass% with respect to the coating liquid total amount from a viewpoint of the temporal stability of a coating liquid.

  The organic solvent used in the present invention is preferably a water-miscible organic solvent. Examples of the water-miscible organic solvent include alcohols (eg, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, tertiary butanol, pentanol, hexanol, cyclohexanol, benzyl alcohol, etc.), many Monohydric alcohols (for example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, thiodiglycol, etc.), polyvalent Alcohol ethers (eg, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether) , Ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, ethylene glycol mono Phenyl ether, propylene glycol monophenyl ether, etc.), amines (eg, ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine) , Triethylenetetramine, tetraethylenepentamine, polyethyleneimine, pentamethyldiethylenetriamine, tetramethylpropylenediamine, etc.), amides (eg, formamide, N, N-dimethylformamide, N, N-dimethylacetamide, etc.), heterocyclic rings (For example, 2-pyrrolidone, N-methyl-2-pyrrolidone, cyclohexyl pyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, etc.), sulfoxides (for example, dimethyl sulfoxide, etc.), sulfones (for example, , Sulfolane and the like), urea, acetonitrile, acetone and the like, and alcohols, polyhydric alcohols, and polyhydric alcohol ethers are particularly preferable. The amount of these organic solvents used may be adjusted as described above so that the water content is less than 10% by mass with respect to the total amount of the coating solution.

  The organic titanium compound monomer, oligomer or hydrolyzate thereof used in the present invention preferably accounts for 50 to 98% by mass in the solid content contained in the coating solution. The solid content ratio is more preferably 50 to 90% by mass, and further preferably 55 to 90% by mass. In addition, it is also preferable to add to the coating composition a polymer of an organic titanium compound (a product obtained by crosslinking the organic titanium compound in advance by hydrolysis) or titanium oxide fine particles.

  The high refractive index layer and medium refractive index layer used in the present invention preferably contain metal oxide particles as fine particles, and further contain a binder polymer.

  When the organic titanium compound hydrolyzed / polymerized by the coating liquid preparation method and the metal oxide particles are combined, the metal oxide particles and the hydrolyzed / polymerized organic titanium compound are firmly bonded, and the hardness and uniform film of the particles It is possible to obtain a strong coating film having both flexibility.

The metal oxide particles used for the high refractive index layer and the medium refractive index layer preferably have a refractive index of 1.80 to 2.80, and more preferably 1.90 to 2.80. The weight average diameter of the primary particles of the metal oxide particles is preferably 1 to 150 nm, more preferably 1 to 100 nm, and most preferably 1 to 80 nm. The weight average diameter of the metal oxide particles in the layer is preferably 1 to 200 nm, more preferably 5 to 150 nm, still more preferably 10 to 100 nm, and more preferably 10 to 80 nm. Most preferred. The average particle diameter of the metal oxide particles is measured by a light scattering method if it is 20-30 nm or more, and by an electron micrograph if it is 20-30 nm or less. The specific surface area of metal oxide particles, as measured values by the BET method is preferably from 10 to 400 m ² / g, more preferably from 20 to 200 m ² / g, with 30 to 150 m ² / g Most preferably it is.

  Examples of the metal oxide particles include at least one selected from Ti, Zr, Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Al, Mg, Si, P, and S. Specific examples of the metal oxide include titanium dioxide (eg, rutile, rutile / anatase mixed crystal, anatase, amorphous structure), tin oxide, indium oxide, zinc oxide, and zirconium oxide. Of these, titanium oxide, tin oxide, and indium oxide are particularly preferable. The metal oxide particles are mainly composed of oxides of these metals and can further contain other elements. The main component means a component having the largest content (mass%) among the components constituting the particles. Examples of other elements include Ti, Zr, Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Al, Mg, Si, P, and S.

  The metal oxide particles are preferably surface-treated. The surface treatment can be performed using an inorganic compound or an organic compound. Examples of inorganic compounds used for the surface treatment include alumina, silica, zirconium oxide and iron oxide. Of these, alumina and silica are preferable. Examples of the organic compound used for the surface treatment include polyols, alkanolamines, stearic acid, silane coupling agents, and titanate coupling agents. Among these, the silane coupling agent is most preferable.

  Two or more types of coupling agents may be used in combination, and in addition to the silane coupling agent, other silane coupling agents may be used. Other silane coupling agents include alkyl esters of orthosilicate (eg, methyl orthosilicate, ethyl orthosilicate, n-propyl orthosilicate, i-propyl orthosilicate, n-butyl orthosilicate, sec-butyl orthosilicate, orthosilicate). Acid t-butyl) and its hydrolyzate.

  The surface treatment with the coupling agent can be carried out by adding the coupling agent to the dispersion of fine particles and leaving the dispersion at a temperature from room temperature to 60 ° C. for several hours to 10 days. In order to accelerate the surface treatment reaction, inorganic acids (for example, sulfuric acid, hydrochloric acid, nitric acid, chromic acid, hypochlorous acid, boric acid, orthosilicic acid, phosphoric acid, carbonic acid), organic acids (for example, acetic acid, polyacrylic acid, Benzenesulfonic acid, phenol, polyglutamic acid), or salts thereof (eg, metal salts, ammonium salts) may be added to the dispersion.

  These silane coupling agents are preferably hydrolyzed with a necessary amount of water in advance. When the silane coupling agent is hydrolyzed, the surfaces of the organic titanium compound and the metal oxide particles described above are easy to react and a stronger film is formed. It is also preferable to add a hydrolyzed silane coupling agent to the coating solution in advance. The water used for this hydrolysis can also be used for the hydrolysis / polymerization of the organic titanium compound.

  In this invention, you may process by combining 2 or more types of surface treatment. The shape of the metal oxide particles is preferably a rice grain shape, a spherical shape, a cubic shape, a spindle shape or an indefinite shape. Two or more kinds of metal oxide particles may be used in combination in the high refractive index layer and the middle refractive index layer.

  The ratio of the metal oxide particles in the high refractive index layer and the medium refractive index layer is preferably 5 to 65% by volume, more preferably 10 to 60% by volume, and still more preferably 20 to 55% by volume. is there.

  The metal oxide particles are supplied to a coating solution for forming a high refractive index layer and a medium refractive index layer in a dispersion state dispersed in a medium. As a dispersion medium for metal oxide particles, it is preferable to use a liquid having a boiling point of 60 to 170 ° C. Specific examples of the dispersion solvent include water, alcohol (eg, methanol, ethanol, isopropanol, butanol, benzyl alcohol), ketone (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), ester (eg, methyl acetate, ethyl acetate). , Propyl acetate, butyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate), aliphatic hydrocarbons (eg, hexane, cyclohexane), halogenated hydrocarbons (eg, methylene chloride, chloroform, carbon tetrachloride), aromatic Group hydrocarbon (eg, benzene, toluene, xylene), amide (eg, dimethylformamide, dimethylacetamide, n-methylpyrrolidone), ether (eg, diethyl ether, dioxane, tetrahydrofuran), ether alcohol (eg, 1-methoxy-2-propanol). Of these, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and butanol are particularly preferable.

  The metal oxide particles can be dispersed in the medium using a disperser. Examples of the disperser include a sand grinder mill (eg, a bead mill with pins), a high-speed impeller mill, a pebble mill, a roller mill, an attritor, and a colloid mill. A sand grinder mill and a high-speed impeller mill are particularly preferred. Further, preliminary dispersion processing may be performed. Examples of the disperser used for the preliminary dispersion treatment include a ball mill, a three-roll mill, a kneader, and an extruder.

  The high refractive index layer and medium refractive index layer used in the present invention preferably use a polymer having a crosslinked structure (hereinafter also referred to as a crosslinked polymer) as a binder polymer. Examples of crosslinked polymers include polymers having saturated hydrocarbon chains such as polyolefin (hereinafter collectively referred to as “polyolefins”), crosslinked products such as polyethers, polyureas, polyurethanes, polyesters, polyamines, polyamides, and melamine resins. . Among them, a crosslinked product of polyolefin, polyether and polyurethane is preferred, a crosslinked product of polyolefin and polyether is more preferred, and a crosslinked product of polyolefin is most preferred. Further, it is further preferable that the crosslinked polymer has an anionic group. The anionic group has a function of maintaining the dispersion state of the inorganic fine particles, and the crosslinked structure has a function of imparting a film forming ability to the polymer and strengthening the film. The anionic group may be directly bonded to the polymer chain or may be bonded to the polymer chain via a linking group, but is bonded to the main chain as a side chain via the linking group. Is preferred.

  Examples of the anionic group include a carboxylic acid group (carboxyl), a sulfonic acid group (sulfo), and a phosphoric acid group (phosphono). Of these, sulfonic acid groups and phosphoric acid groups are preferred. Here, the anionic group may be in a salt state. The cation that forms a salt with the anionic group is preferably an alkali metal ion. Moreover, the proton of the anionic group may be dissociated. The linking group that binds the anionic group and the polymer chain is preferably a divalent group selected from —CO—, —O—, an alkylene group, an arylene group, and combinations thereof. The crosslinked polymer which is a preferable binder polymer is preferably a copolymer having a repeating unit having an anionic group and a repeating unit having a crosslinked structure. In this case, the ratio of the repeating unit having an anionic group in the copolymer is preferably 2 to 96% by mass, more preferably 4 to 94% by mass, and most preferably 6 to 92% by mass. preferable. The repeating unit may have two or more anionic groups.

  The crosslinked polymer having an anionic group may contain other repeating units (a repeating unit having neither an anionic group nor a crosslinked structure). Other repeating units are preferably a repeating unit having an amino group or a quaternary ammonium group and a repeating unit having a benzene ring. The amino group or the quaternary ammonium group has a function of maintaining the dispersed state of the inorganic fine particles, like the anionic group. The benzene ring has a function of increasing the refractive index of the high refractive index layer. The amino group, the quaternary ammonium group, and the benzene ring can obtain the same effect even if they are contained in a repeating unit having an anionic group or a repeating unit having a crosslinked structure.

  In the crosslinked polymer containing a repeating unit having an amino group or a quaternary ammonium group as a constituent unit, the amino group or quaternary ammonium group may be directly bonded to the polymer chain, or may be a side chain via a linking group. May be bonded to the polymer chain, but the latter is more preferred. The amino group or quaternary ammonium group is preferably a secondary amino group, a tertiary amino group or a quaternary ammonium group, and more preferably a tertiary amino group or a quaternary ammonium group. The group bonded to the nitrogen atom of the secondary amino group, tertiary amino group or quaternary ammonium group is preferably an alkyl group, more preferably an alkyl group having 1 to 12 carbon atoms, still more preferably a carbon number. 1 to 6 alkyl groups. The counter ion of the quaternary ammonium group is preferably a halide ion. The linking group that connects the amino group or quaternary ammonium group to the polymer chain is a divalent group selected from —CO—, —NH—, —O—, an alkylene group, an arylene group, and combinations thereof. Is preferred. When the crosslinked polymer includes a repeating unit having an amino group or a quaternary ammonium group, the ratio is preferably 0.06 to 32% by mass, more preferably 0.08 to 30% by mass, Most preferably, it is 0.1-28 mass%.

  The cross-linked polymer is prepared by a polymerization reaction at the same time as or after application of the coating solution by preparing a coating solution for forming a high refractive index layer and a medium refractive index layer by blending a monomer for generating a crosslinked polymer. Is preferred. Each layer is formed with the production of the crosslinked polymer. The monomer having an anionic group functions as a dispersant for inorganic fine particles in the coating solution. The monomer having an anionic group is preferably used in an amount of 1 to 50% by mass, more preferably 5 to 40% by mass, and still more preferably 10 to 30% by mass with respect to the inorganic fine particles. The monomer having an amino group or a quaternary ammonium group functions as a dispersion aid in the coating solution. The monomer having an amino group or a quaternary ammonium group is preferably used in an amount of 3 to 33% by mass based on the monomer having an anionic group. These monomers can be made to function effectively before application of the coating liquid by a method of forming a crosslinked polymer by polymerization reaction simultaneously with or after application of the coating liquid.

  As the monomer used in the present invention, a monomer having two or more ethylenically unsaturated groups is most preferable, and examples thereof include esters of polyhydric alcohol and (meth) acrylic acid (eg, ethylene glycol di ( (Meth) acrylate, 1,4-dichlorohexanediacrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol Tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3-cyclohexanetetramethacrylate, polyurethane polyacrylate, polyester Terpolyacrylate), vinylbenzene and its derivatives (eg, 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1,4-divinylcyclohexanone), vinylsulfone (eg, divinylsulfone), acrylamide (E.g., methylenebisacrylamide) and methacrylamide. Commercially available monomers may be used as the monomer having an anionic group and the monomer having an amino group or a quaternary ammonium group. As a commercially available monomer having a commercially available anionic group, KAYAMAPMPM-21, PM-2 (manufactured by Nippon Kayaku Co., Ltd.), Antox MS-60, MS-2N, MS-NH4 (manufactured by Nippon Emulsifier Co., Ltd.) , Aronix M-5000, M-6000, M-8000 series (manufactured by Toagosei Co., Ltd.), Biscote # 2000 series (manufactured by Osaka Organic Chemical Industry Co., Ltd.), New Frontier GX-8289 (Daiichi Kogyo Seiyaku Co., Ltd.) ) Ester, NK ester CB-1, A-SA (manufactured by Shin-Nakamura Chemical Co., Ltd.), AR-100, MR-100, MR-200 (manufactured by Eighth Chemical Industry Co., Ltd.) and the like. Examples of commercially available monomers having a commercially available amino group or quaternary ammonium group include DMAA (manufactured by Osaka Organic Chemical Industry Co., Ltd.), DMAEA, DMAPAA (manufactured by Kojin Co., Ltd.), and Bremer QA (Nippon Yushi Co., Ltd.). ) And New Frontier C-1615 (Daiichi Kogyo Seiyaku Co., Ltd.).

  For the polymerization reaction of the polymer, a photopolymerization reaction or a thermal polymerization reaction can be used. A photopolymerization reaction is particularly preferable. A polymerization initiator is preferably used for the polymerization reaction. For example, the thermal polymerization initiator mentioned later used in order to form the binder polymer of an anti-glare hard-coat layer, and a photoinitiator are mentioned.

  A commercially available polymerization initiator may be used as the polymerization initiator. In addition to the polymerization initiator, a polymerization accelerator may be used. The addition amount of the polymerization initiator and the polymerization accelerator is preferably in the range of 0.2 to 10% by mass of the total amount of monomers. The coating liquid (dispersion of inorganic fine particles containing monomer) may be heated to promote polymerization of the monomer (or oligomer). Moreover, it may heat after the photopolymerization reaction after application | coating, and may additionally process the thermosetting reaction of the formed polymer.

  For the medium refractive index layer and the high refractive index layer, it is preferable to use a polymer having a relatively high refractive index. Examples of the polymer having a high refractive index include polystyrene, styrene copolymer, polycarbonate, melamine resin, phenol resin, epoxy resin, and polyurethane obtained by reaction of cyclic (alicyclic or aromatic) isocyanate and polyol. . Polymers having other cyclic (aromatic, heterocyclic, and alicyclic) groups and polymers having halogen atoms other than fluorine as substituents can also be used with a high refractive index.

  In addition to the above-described components (metal oxide particles, polymer, dispersion medium, polymerization initiator, polymerization accelerator), each layer of the antireflection layer or coating liquid thereof includes a polymerization inhibitor, a leveling agent, a thickener, and an anti-coloring agent. An agent, an ultraviolet absorber, a silane coupling agent, an antistatic agent or an adhesion promoter may be added.

  In order to promote hydrolysis or hardening of the composition containing a metal alkoxide after coating of the medium to high refractive index layer and the low refractive index layer used in the present invention, it is preferable to irradiate active energy rays. More preferably, the active energy ray is irradiated every time each layer is coated.

The active energy ray used in the present invention can be used without limitation as long as it is an energy source that activates a compound such as ultraviolet ray, electron beam, and γ ray, but ultraviolet ray and electron beam are preferable, and handling is particularly simple and high energy. Ultraviolet rays are preferred because they can be easily obtained. As the ultraviolet light source for photopolymerizing the ultraviolet reactive compound, any light source that generates ultraviolet light can be used. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used. An ArF excimer laser, a KrF excimer laser, an excimer lamp, synchrotron radiation, or the like can also be used. Irradiation conditions vary depending on each lamp, but the amount of irradiation light is preferably ²⁰ to 10,000 mJ / cm ² , more preferably 100 to 2,000 mJ / cm ² , and particularly preferably 400 to 2,000 mJ / cm 2. ² .

  When ultraviolet rays are used, the multilayer antireflection layer may be irradiated one by one, or may be irradiated after lamination. From the viewpoint of productivity, it is preferable to irradiate ultraviolet rays after laminating multiple layers.

  Moreover, an electron beam can be used similarly. As an electron beam, 50 to 1000 keV, preferably 100 to 100, emitted from various electron beam accelerators such as a cockroft Walton type, a bandegraph type, a resonance transformation type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type. An electron beam having an energy of 300 keV can be given.

(Antireflection layer thickness)
The thickness of each refractive index layer constituting the antireflection layer is preferably in the range of 1 to 200 nm, more preferably 5 to 150 nm, but each film has an appropriate thickness depending on the refractive index of each layer. It is preferable to select.

(Reflectivity of antireflection layer)
The antireflection layer used in the present invention preferably has an average reflectance at 450 to 650 nm of 1% or less, particularly preferably 0.5% or less. Further, the minimum reflectance in this range is particularly preferably from 0.0 to 0.3%.

  The refractive index and film thickness of the antireflection layer can be calculated and calculated by measuring the spectral reflectance. Moreover, the reflective optical characteristic of the produced low reflection film can measure a reflectance on the conditions of a 5-degree regular reflection using a spectrophotometer. In this measurement method, after roughening the substrate surface on which the antireflection layer is not applied, a light absorption treatment is performed using a black spray to prevent reflection of light on the back surface of the film and reflectivity. Is measured.

  In the measurement, the transmittance at a transmittance of 550 nm is measured using a spectrophotometer with reference to air.

<Polarizing plate>
In the present invention, it is preferable to use a long λ / 4 plate (stretched film) as a long polarizing plate formed by laminating at least one surface of a long polarizer.

  The polarizing plate according to the present invention uses a stretched polyvinyl alcohol doped with iodine or a dichroic dye as a polarizer, and is a λ / 4 plate (stretched film) of the present invention. It can bond and manufacture by the structure of a child / retardation film.

  In addition, when using the polarizing plate which concerns on this invention for the liquid crystal display device which is a stereoscopic video display apparatus, the said (lambda) / 4 board is bonded by the visual recognition side.

  The λ / 4 plate (retardation film) is preferably a polymer film, and is preferably easy to manufacture, optically uniform, and optically transparent. Any of these may be used, for example, cellulose ester film, polyester film, polycarbonate film, polyarylate film, polysulfone (including polyethersulfone) film, polyethylene terephthalate, polyethylene naphthalate. Polyester film, polyethylene film, polypropylene film, cellophane, cellulose diacetate film, cellulose acetate butyrate film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film, syndiotactic polystyrene film, polycarbonate film, norbornene resin Film, polymethylpentene film, polyetherketone film, Polyether ketone imide film, a polyamide film, a fluororesin film, a nylon film, a cycloolefin polymer film, a polyvinyl acetal resin film, there may be mentioned polymethyl methacrylate film, or an acrylic film or the like, but are not limited to.

  In the case of a cellulose ester film, cellulose acetate, plasticizer, ultraviolet absorber, antioxidant, retardation adjusting agent, matting agent, deterioration inhibitor, peeling aid used in the above-mentioned retardation film (stretched film), A surfactant or the like can be preferably used.

  Retardation films Ro and Rt defined by the above formula are 20 to 150 nm and 70 to 70 respectively for retardation films bonded to the surface opposite to the surface on which the λ / 4 plate is bonded to the polarizer. It is preferable that the retardation film is 400 nm, or 0 nm ≦ Ro ≦ 2 nm and −15 nm ≦ Rt ≦ 15 nm.

  As the retardation film, for example, a method of supporting a discotic liquid crystalline compound, which is a compound having negative uniaxiality, on a support (for example, see JP-A-7-325221), positive optical anisotropy. A method of supporting a nematic polymer liquid crystal compound having a hybrid orientation in which a pretilt angle of liquid crystal molecules changes in the depth direction on a support (see, for example, JP-A-10-186356), A nematic liquid crystal compound having positive optical anisotropy is formed into a two-layer structure on a support, and the orientation direction of each layer is set to approximately 90 ° to give pseudo-uniaxially similar optical characteristics. In place of a retardation film provided with an optically anisotropic layer on a support or a conventional TAC film (for example, see JP-A-8-15681) A retardation film having a retardation film function by stretching a cellulose derivative film, saponifying the cellulose derivative film, and laminating a PVA polarizer (see, for example, JP-A-2003-270442). In addition, an optical compensation film by a method of adding a retardation adjusting agent to a cellulose ester film to obtain a retardation film (see, for example, JP 2000-275434 A and JP 2003-344655 A) can be mentioned. It is not limited to these.

  For example, as a commercially available cellulose ester film, Konica Minoltak KC8UX, KC4UX, KC5UX, KC8UCR3, KC8UCR4, KC8UCR5, KC8UY, KC4UY, KC12UR, KC16UR, KC4UE, KC4UE, KC4FR, KC4FR-1 And the like) are also preferably used.

  The film thickness of the polarizer is 5 to 40 μm, preferably 5 to 30 μm, and particularly preferably 5 to 20 μm.

  The polarizing plate can be produced by a general method. The stretched film according to the present invention subjected to alkali saponification treatment is preferably bonded to at least one surface of a polarizer produced by immersing and stretching a polyvinyl alcohol film in an iodine solution by using a completely saponified polyvinyl alcohol aqueous solution. . It is preferable to paste the retardation film on the other surface.

  The polarizing plate can be constructed by further bonding a protective film on one surface of the polarizing plate and a separate film on the other surface. The protective film and the separate film are used for the purpose of protecting the polarizing plate at the time of shipping the polarizing plate and at the time of product inspection.

<Liquid crystal display device>
In the present invention, a sheet-like film formed by cutting a long retardation film (stretched film), and a sheet-like polarizing plate formed by cutting the long polarizing plate are provided. It can be set as the liquid crystal display device of an aspect. For example, the liquid crystal display device according to the present invention can be manufactured by using the liquid crystal display device in which the polarizing plate according to the present invention is bonded to the surface on the viewing side of the liquid crystal cell.

  The polarizing plate according to the present invention is a reflective, transmissive, transflective LCD, super twisted nematic (STN) mode, twisted nematic (TN) mode, in-plane switching (IPS) mode, vertical alignment (VA) mode, bend. It is preferably used for a liquid crystal display device in a nematic (OCB: Optically Aligned Birefringence) mode and a hybrid alignment (HAN: Hybrid Aligned Nematic) mode.

  In the present invention, in particular, the liquid crystal display device is preferably a stereoscopic image display device. That is, the λ / 4 plate which is the retardation film (stretched film) according to the present invention can be used in various modes in a stereoscopic image display device. For example, a stereoscopic image display device comprising a liquid crystal display device and liquid crystal shutter glasses, wherein the liquid crystal shutter glasses are provided with (1) a λ / 4 plate, a liquid crystal cell, and a polarizer in this order (FIG. 5). ), Or (2) a λ / 4 plate, a polarizer, a liquid crystal cell, and a polarizer are provided in this order (FIG. 6). Can do.

  In any case, the front polarizing plate of the liquid crystal display device has a configuration in which a λ / 4 plate, a polarizer, a retardation film, a cell, and a polarizer are provided in this order.

  In the present invention, with the above-described aspect and configuration, crosstalk or luminance reduction and color change when tilting the head when viewing a stereoscopic (3D) image can be reduced, and excellent visibility with respect to the use environment can be maintained. Therefore, a stereoscopic image display device with higher durability against the use environment can be obtained.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

<Example>
<Preparation of film 1>
<Preparation of raw fabric (roll-shaped long film)>
(Preparation of polyester compound B)
In a nitrogen atmosphere, 4.85 g of dimethyl terephthalate, 4.4 g of 1,2-propylene glycol, 6.8 g of p-toluic acid, and 10 mg of tetraisopropyl titanate were mixed and stirred at 140 ° C. for 2 hours. Stirring was carried out at ° C for 16 hours. Next, the temperature was lowered to 170 ° C., and unreacted 1,2-propylene glycol was distilled off under reduced pressure to obtain comparative polyester compound B.

Acid value: 0.1
Number average molecular weight: 490
Dispersity: 1.4
Component content of molecular weight 300-1800: 90%
Hydroxyl (hydroxyl) value: 0.1
Hydroxyl group (hydroxyl group) content: 0.04%
In addition, since the polyester compound B uses the monocarboxylic acid 2 times mole with respect to dicarboxylic acid, the terminal is toluic acid ester.

<Fine particle dispersion 1>
Fine particles (Aerosil R812 manufactured by Nippon Aerosil Co., Ltd.) 11 parts by weight Ethanol 89 parts by weight The above was stirred and mixed with a dissolver for 50 minutes, and then dispersed with Manton Gorin.

<Fine particle addition liquid 1>
The fine particle dispersion 1 was slowly added to the dissolution tank containing methylene chloride with sufficient stirring. Further, the particles were dispersed by an attritor so that the secondary particles had a predetermined particle size. This was filtered through Finemet NF manufactured by Nippon Seisen Co., Ltd. to prepare a fine particle additive solution 1.

Methylene chloride 50 parts by mass Fine particle dispersion 1 50 parts by mass A main dope solution having the following composition was prepared. First, methylene chloride and ethanol were added to the pressure dissolution tank. Cellulose ester, carboxylic acid sugar ester compound, polyester, TINUVIN 928, and fine particle additive solution 1 were added to a pressure dissolution tank containing a solvent while stirring. This is completely dissolved with heating and stirring. This was designated as Azumi Filter Paper No. The main dope solution was prepared by filtration using 244.

<Composition of main dope solution>
Methylene chloride 340 parts by weight Ethanol 64 parts by weight Cellulose ester (cellulose acetate propionate: acetyl group substitution degree 1.5, propionyl group 0.9, total substitution degree 2.4; weight average molecular weight 190,000) 100 parts by weight carboxylic acid Sugar ester compound A (see Table 3) 10.0 parts by weight Polyester compound B (see Table 3) 2.5 parts by weight TINUVIN 928 (manufactured by BASF Japan) 1.5 parts by weight Fine particle additive solution 1 3.5 parts by weight The dope solution was prepared by putting in a sealed container and dissolving with stirring. Next, an endless belt casting apparatus was used to uniformly cast the dope solution on a stainless steel belt support at a temperature of 33 ° C. and a width of 2000 mm. The temperature of the stainless steel belt was controlled at 30 ° C.

  On the stainless steel belt support, the solvent was evaporated until the residual solvent amount in the cast (cast) film became 75%, and then peeled off from the stainless steel belt support with a peeling tension of 110 N / m.

  The peeled cellulose ester film was stretched 1% in the width direction using a tenter while applying heat at 160 ° C. The residual solvent at the start of stretching was 15%.

  Next, drying was terminated while the drying zone was conveyed by a number of rolls. The drying temperature was 130 ° C. and the transport tension was 100 N / m.

  As described above, a roll-shaped long film 1 having a dry film thickness of 102 μm was obtained.

<Example 1>
The roll-shaped long original fabric film 1 was set in a slidable feeding device of the apparatus shown in FIG. 3 (a-2) and supplied to an oblique stretching machine. At that time, the distance between the main shaft of the guide roll closest to the inlet of the oblique stretching apparatus and the gripping tool (clip gripping part) of the oblique stretching apparatus was 80 cm. A clip with a length of 2 inches in the conveying direction was used, and a guide roll with a diameter of 10 cm was used. The tenter was stretched in the transverse direction at a stretching temperature of 190 ° C. and a stretching ratio of 1.8 times, and then contracted 0.71 times in the direction perpendicular to the stretching when the rail was bent 45 °. The stretched film was controlled so that the fluctuation in the take-up tension was less than 3% by performing feedback control in which the change in the tension measured with the first roll on the outlet side of the obliquely stretched tenter was reflected in the take-up motor rotation speed. Thereafter, both ends of the film are trimmed, the conveyance direction is changed by a conveyance direction changing device composed of an airflow roll, the film is wound by a slidable winding device, and a roll-like long stretched retardation film 1 having a width of 2000 mm is obtained. Obtained.

  Moreover, it extended | stretched using the heating apparatus for temperature control over the width direction of a film. The heating device controlled the temperature so that the thickness of the film in the film width direction after stretching was approximately the same as the thickness direction film thickness distribution before stretching.

  The obtained long retardation film (λ / 4 plate) 1 was uniform in the longitudinal direction of the film. Properties of the obtained retardation film (λ / 4 plate) 1 (appearance, width yield, retardation, orientation angle, wavelength dispersion, haze, ultraviolet transmittance, deterioration of polarizer fading, squeak value, oil resistance, heat shrinkage Are shown in Tables 1 and 2.

  On the surface of the obtained retardation film (λ / 4 plate) 1, the following hard coat layer was provided, and thermal wrinkles, adhesion, and pencil hardness were evaluated. It shows in Table 1 and Table 2. The results are also shown in Tables 1 and 2.

<Application of hard coat layer>
The following hard coat layer coating solution 1 was die coated, dried at 80 ° C., and then irradiated with 120 mJ / cm ² of ultraviolet light with a high pressure mercury lamp to provide a clear hard coat layer so that the film thickness after curing was 6 μm.

(Coating solution 1 for hard coat layer)
Ethanol 100 parts by mass Pentaerythritol triacrylate 100 parts by mass 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by BASF Japan Ltd.) 5 parts by mass 2-methyl-1- [4- (methylthio) phenyl] -2-monoforino -1-one (Irgacure 907, manufactured by BASF Japan) 3 parts by weight BYK-331 (silicone surfactant, manufactured by Big Chemie Japan Co., Ltd.)
5 parts by mass Example films 2 to 11 were prepared by changing the film thickness of the film 1, the amount and type of additives, the stretching temperature and the magnification as shown in Tables 1 and 2. Table 3 shows additive types.

  Further, Comparative Films 12 to 15 were produced by the following method.

<Preparation of film 12>
The film 12 was produced by the method of Example 1 of Unexamined-Japanese-Patent No. 2009-214441.

<Preparation of film 13>
A film 13 was produced with reference to the examples of JP 2010-173261 A. The stretching temperature was 145 ° C.

<Preparation of film 14>
The film 14 was produced by the method of Example 1 of Japanese Patent No. 03734211.

<Preparation of film 15>
A film 15 was produced with reference to Example 1 of JP2009-48204A. However, after casting, it is dried without stretching. Then, it extended | stretched on the same conditions as the film 3 with the diagonal extending | stretching machine of Fig.3 (a-2).

<Evaluation>
(1) Appearance (twill, wrinkles)
A wide film of 1 m or more was placed on a black base, visually confirmed and wrinkled, and evaluated based on the following criteria.
○: No creases or wrinkles are observed at all ×: creases or wrinkles are observed (2) Width yield In the film transport line after stretching, using an infrared film thickness meter (manufactured by Kurabo Industries, RX-100) The traverse measurement was performed at a pitch of 5 mm in the width direction, and for each position, 100 points of data were obtained at intervals of 50 mm in the width direction and at intervals of 5 m in the flow direction.

  With respect to the obtained data, an average value and a standard deviation σ of 100 points in the flow direction at each width position were calculated. A width having a standard deviation σ of 0.3 μm or less was defined as an effective range, and the width yield was defined as follows.

Width yield = hand length effective ÷ width after stretching x 100 (%)
(3) Orientation angle θ, in-plane retardation Ro, wavelength dispersion Using a phase difference measuring device (manufactured by Oji Scientific Co., Ltd., KOBRA-WXK), the orientation angle θ of the slow axis and Ro at 550 nm were determined. Further, Ro was measured at 480 to 630 nm, and chromatic dispersion was defined as follows.

Chromatic dispersion = Ro (Ro (480)) at 480 nm ÷ Ro (Ro (630)) at 630 nm
(4) Haze (all haze)
It measured using the haze meter (1001DP type, Nippon Denshoku Industries Co., Ltd. product).
(Internal haze)
From a haze value measured in a state where two drops of glycerin were dropped on the surface of the film and sandwiched from both sides by two glass plates with a thickness of 1.3 mm (MICRO SLIDE GLASS part number S9213, manufactured by MATSANAMI), between the sheets The value obtained by subtracting the haze measured with several drops of glycerin.
(5) Ultraviolet transmittance The spectral absorption spectrum of the film was measured with Spectrophotometer U-3200 (manufactured by Hitachi, Ltd.), and the transmittance at 380 nm was determined.
(6) Polarizer fading deterioration (preparation of polarizing plate)
A 120 μm thick polyvinyl alcohol film was immersed in 100 kg of an aqueous solution containing 1 kg of iodine and 4 kg of boric acid and stretched 6 times at 50 ° C. to form a polarizing film. Using this polarizing film as a polarizer, a sample film having been subjected to the following alkali saponification treatment on both sides was attached to the polarizer using a completely saponified polyvinyl alcohol 5% aqueous solution as an adhesive so as to sandwich the polarizer. A laminated polarizing plate was produced.

<Alkali saponification treatment>
Saponification step 2N-NaOH 50 ° C. 90 seconds water washing step Water 30 ° C. 45 seconds neutralization step 10 mass% HCl 30 ° C. 45 seconds water washing step Water 30 ° C. 45 seconds Water saponification, water washing, neutralization, water washing And then dried at 80 ° C.
(Damp heat durability)
For the polarizing plate produced by the above method, first, the parallel transmittance and the direct transmittance were measured, and the degree of polarization was calculated according to the following formula. Thereafter, each polarizing plate was forcedly deteriorated at 80 ° C. and 90% for 300 hours, and then the parallel transmittance and the direct transmittance were measured again, and the degree of polarization was calculated according to the following formula. The amount of change in polarization degree was determined by the following formula.
Polarization degree P = ((H0−H90) / (H0 + H90)) 1/2 × 100
Polarization degree change = P0−P300
H0: parallel transmittance H90: direct transmittance P0: degree of polarization before forced degradation P300: degree of polarization after 300 hours of forced degradation (light resistance)
Using the same measurement method as described above, the amount of change in polarization after light irradiation for 250 hours was determined by the following formula using a weather resistance tester (Isuper UV tester, manufactured by Iwasaki Electric Co., Ltd.).
Polarization degree P = ((H0−H90) / (H0 + H90)) 1/2 × 100
Polarization degree change = P0−P250H
P250: Degree of polarization after 250 hours of light irradiation (7) Squeaking value The dynamic friction coefficient between the film surface and the back surface is cut out so that the front and back surfaces of the film are in contact with each other according to JIS-K-7125 (1987), and the weight is 200 g. The weight was pulled horizontally under the conditions of a sample moving speed of 100 mm / min and a contact area of 80 mm × 200 mm, the average load (F) while the weight was moving was measured, and the squeak value (μ) was determined from the following formula.
Squeaking value (μ) = F (g) / weight of weight (g)
(8) Oil resistance About 2-3 drops of limonene detergent is dropped on the film and left for 3 hours. Thereafter, the sample was wiped off with a soft cloth, visually checked for dropping marks, and evaluated based on the following criteria.
○: No dripping traces are observed at all ×: Dripping traces are observed (9) Heat shrinkage 4 hours in a room where the film is cut out in the width direction 12 cm × longitudinal direction 12 cm and conditioned at a temperature of 23 ° C. and a relative humidity of 55%. After humidity adjustment, marks were marked with a cutter at intervals of about 10 cm in the width and length, and the distance (L1) was measured. Next, the film is stored in an oven at 140 ° C. for 45 minutes. The film was again conditioned for 4 hours in a room conditioned at a temperature of 23 ° C. and a relative humidity of 55%, and the distance (L2) between the marks was measured. The dimensional change rate was obtained by the following formula, and the average value of the width direction dimensional change rate and the longitudinal direction dimensional change rate was used as a measure of heat shrinkage. The smaller the dimensional change rate, the greater the thermal shrinkage.
Dimensional change rate (%) = {(L2-L1) / L1} × 100
Thermal shrinkage = (width direction dimensional change rate + longitudinal direction dimensional change rate) / 2
(10) Thermal wrinkles at the time of application The presence or absence of wrinkles on the back surface of the film was visually observed after coating with a green lamp in a dark room.
○: Wrinkles are not seen at all Δ: Wrinkles are barely visible ×: Wrinkles are clearly seen XX: Wrinkles are visible even in white light in a bright room (11) Hard coat adhesion, light-resistant adhesion, wet heat durability adhesion (immediate adhesion)
In accordance with JIS K 5400, make 11 cuts vertically and horizontally at intervals of 1 mm, make 1 mm square, 100 grids, apply cellophane tape, peel off quickly at an angle of 90 degrees, and do not peel off I counted the number of grids remaining in the board.

  The greater the number, the better the adhesion.

(Light resistance)
With the hard coat surface facing up, the sample was irradiated with light for 250 hours with a weather resistance tester (eye super UV tester, manufactured by Iwasaki Electric Co., Ltd.), and then measured by the same method as that for immediate contact.

(Damp heat durability)
After forced degradation for 300 hours under the condition of 80 ° C. and 90%, measurement was performed by the same method as that for immediate contact.
(12) Pencil Hardness According to the pencil hardness evaluation method specified by JIS K 5400, scratching was repeated 5 times with a pencil of each hardness using a 1 kg weight, and the hardness of up to one scratch was measured. The higher the number, the higher the hardness.

  The contents and evaluation results of each film (λ / 4) are shown in Tables 1 to 3.

  As is apparent from the results shown in Tables 1 to 3, it can be seen that the film (λ / 4 plate) according to the present invention is excellent in film properties, surface processing suitability, and the like.

  In addition, although the film ((lambda) / 4 board) based on this invention was bonded to the panel side of SONY 3D glasses TDG-BR100, and the stripe at the time of 3D image viewing was observed about the produced liquid crystal display device, the film based on this invention It was found that the liquid crystal display device using (λ / 4 plate) is excellent without any streak failure.

  The liquid crystal display device peels off the pre-bonded front plate of the 60-type display BRAVIA LX900 made by SONY, removes the filler between the polarizing plate on the front surface of the panel and the front plate, and the front side of the panel previously bonded The polarizing plate was peeled off, and the prepared polarizing plates were each bonded to the front surface of the glass surface of the liquid crystal cell. At that time, the direction of bonding of the polarizing plate is absorbed so that the surface of the film (λ / 4 plate) of the present invention is on the viewing side and in the same direction as the polarizing plate previously bonded. The liquid crystal display devices were each manufactured in such a manner that the axes were directed.

DESCRIPTION OF SYMBOLS 1 Original film 2-1 Right film holding start point 2-2 Left film holding start point 3-1 Trajectory of right film holding means 3-2 Trajectory of left film holding means 4 Tenter 5-1 Right film Holding end point 5-2 Left film holding end point 6 Obliquely stretched film 7-1 Film feeding direction 8-1 Tenter inlet side guide roll 8-2 Tenter outlet side guide roll 9 Film stretching direction DR1 Feeding direction DR2 Winding direction θi Feeding angle (angle formed by feeding direction and winding direction)
CR, CL Gripping device Wo Width of film before stretching W Width of film after stretching A Liquid crystal shutter glasses A1, A4 Polarizer A2 Liquid crystal cell A3 λ / 4 plate B Liquid crystal display device (for example, television (TV))
C polarizing plate C1 λ / 4 plate C2 polarizer C3 retardation film C4 polarizer protective film D liquid crystal cell E polarizing plate F backlight HC hard coat layer AR antireflection layer a absorption axis b slow axis

Claims (12)

A λ / 4 plate containing a compound represented by the following general formula (PEI) and a cellulose ester resin, which is stretched in a direction oblique to the longitudinal direction, and has a temperature of 23 ° C. and a relative humidity of 55% RH. The λ / 4 plate is characterized in that the in-plane retardation Ro (550) measured at a measurement wavelength of 550 nm is in the range of 100 to 160 nm and the orientation angle θ is in the range of 40 to 50 °.
Formula (PEI): B- (GA) _n -GB
(B represents a benzene monocarboxylic acid residue. G represents an alkylene glycol residue having 2 to 12 carbon atoms, an aryl glycol residue having 6 to 12 carbon atoms, or an oxyalkylene glycol residue having 4 to 12 carbon atoms. And A represents an alkylene dicarboxylic acid residue having 4 to 12 carbon atoms or an aryl dicarboxylic acid residue having 6 to 12 carbon atoms, and n represents an integer of 0 or more.)   the log P value is 6.0 or less and the SP value in the Fedors method is in the range of 8.0 to 12.0, or the log P value is in the range of 6.1 to 12.0, And a λ / 4 plate containing a compound having an SP value in the range of 8.0 to 10.0 by the Fedors method and a cellulose ester resin, and is stretched in a direction oblique to the longitudinal direction. In-plane retardation Ro (550) measured at a measurement wavelength of 550 nm at a temperature of 23 ° C. and a relative humidity of 55% RH is in the range of 100 to 160 nm, and the orientation angle θ is in the range of 40 to 50 °. A λ / 4 plate characterized by the above.   The λ / 4 plate according to claim 1 or 2, which comprises a compound having a 1,3,5-triazine ring. The acetyl group substitution degree of the cellulose ester resin is X and the propionyl group substitution degree is Y, and X and Y satisfy the following formulas (1) and (2). The λ / 4 plate according to any one of 3 to 3.
Formula (1): 2.0 ≦ (X + Y) ≦ 2.8
Formula (2): 0 ≦ Y ≦ 1.0 The cellulose ester resin in which the cellulose ester resin satisfying the formula (1) and the formula (2) contains a cellulose ester resin satisfying the following formula (1a) and the formula (2) and a cellulose ester resin satisfying the following formula (1b). The λ / 4 plate according to claim 4, which is a resin.
Formula (1a): 2.0 ≦ (X + Y) <2.5
Formula (1b): 2.5 ≦ (X + Y) ≦ 2.8   The λ / 4 plate according to any one of claims 1 to 5, wherein a transmittance of light having a wavelength of 380 nm is 10% or less.   The λ / 4 plate according to any one of claims 1 to 6, wherein the surface has a clear hard coat layer or an antiglare hard coat layer.   The λ / 4 plate according to claim 7, wherein the antiglare hard coat layer does not contain fine particles.   A λ / 4 plate manufacturing method for manufacturing the λ / 4 plate according to any one of claims 1 to 8, wherein the original film is first stretched in the lateral direction, A method of manufacturing a λ / 4 plate, comprising a step of curving the conveying direction while contracting in the vertical direction.   A λ / 4 plate according to any one of claims 1 to 8, comprising a λ / 4 plate.   A liquid crystal display device comprising the λ / 4 plate according to any one of claims 1 to 8.   A stereoscopic image display device comprising the λ / 4 plate according to any one of claims 1 to 8.

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