JPWO2012026245A1 - Hard coat film, polarizing plate and liquid crystal display device - Google Patents

Abstract

An object of the present invention is to provide a hard coat film that has good adhesion to a base film and has high transparency even in a high temperature and high humidity environment. The hard coat film of the present invention is a hard coat film having a hard coat layer on a cellulose acetate film having an acetylation degree of 51.0% to 56.0%, the cellulose acetate film containing a sugar ester compound, The pencil hardness of the hard coat film is 2H or more and 7H or less (measured value based on JIS K5400).

Description

  The present invention relates to a novel hard coat film, a polarizing plate using the hard coat film, and a liquid crystal display device using the polarizing plate.

  Liquid crystal display devices are widely used in monitors for personal computers and portable devices, and for television applications because of their various advantages, such as low voltage and low power consumption, enabling miniaturization and thinning. Since liquid crystal display devices for television are expected to be viewed from various angles, there is a strong demand for viewing angle dependency, and an optical compensation film (retardation film) having an optically anisotropic layer is used. Yes. A film having a hard coat layer (hard coat film) is used on the outermost surface of the liquid crystal display device in order to prevent physical damage.

  In general, a panel of a liquid crystal display device has a structure in which a liquid crystal cell is sandwiched between two polarizing plates. The polarizing plate used on the surface side is oriented by stretching a polyvinyl alcohol (hereinafter abbreviated as PVA) film in which iodine or a dichroic dye is adsorbed and dyed between a hard coat film and a retardation film in a certain direction. It has a three-layer structure with a polarizing element (polarizing film) interposed therebetween. As the retardation film, a film containing a norbornene polymer is used because of high optical anisotropy (birefringence), uniformity of retardation, and small change in optical properties due to low moisture permeability (for example, patents) Reference 1).

  On the other hand, a polarizing plate is produced by laminating a hard coat film and a retardation film after saponification treatment with an alkaline aqueous solution, followed by washing with water and drying. However, because the film containing norbornene polymer has low moisture permeability and the hard coat layer also has low moisture permeability, moisture cannot be removed sufficiently by drying alone, and adhesiveness is insufficient due to the influence of the remaining moisture. There were problems such as unevenness in the film and warpage after bonding.

  For this reason, in order to improve the efficiency of moisture removal, a cellulose triacetate film having a degree of acetylation of 59.5% or more, which is generally used as a base film of a hard coat film, has a higher moisture permeability of 51.0%. When% to 56.0% cellulose acetate film was used, there was a problem that adhesion between the cellulose acetate film and the hard coat layer was difficult to take. In particular, after the weather resistance test assuming outdoor use such as digital signage, the above-mentioned problem was remarkable.

  A technique for improving the interlayer adhesion between the base film and the hard coat layer is disclosed in Patent Document 2, for example. Patent Document 2 discloses a hard coat layer cured with a component containing a polyfunctional (meth) acrylic monomer, a (meth) acrylic monomer having a hydroxyl group, a radical photopolymerization initiator, and a fluorine-containing compound having a polymerizable group. It is a hard coat film in which the surface free energy is 20 mN / m or less and the film thickness of the hard coat layer is controlled to 5 to 25 μm. In the technique of Patent Document 2, the interlayer adhesion before the weather resistance test is improved to some extent, but the interlayer adhesion after the weather resistance test is not improved, and the degree of acetylation is 51.0% as a base film having high moisture permeability. No mention or mention is made about interlayer adhesion with the hard coat layer when a cellulose acetate film of ˜56.0% is used.

JP 2008-31304 A JP 2009-263600 A

  The present invention has been made in view of the above problems, and even when a cellulose acetate film having a high moisture permeability and an acetylation degree of 51.0% to 56.0% is used, the hard coat layer, the cellulose acetate film, An object of the present invention is to provide a hard coat film having good interlayer adhesion, a production method thereof, and an excellent polarizing plate and a liquid crystal display device using the same.

  As a result of intensive studies, the present inventors have found that the above-mentioned problems can be solved by a hard coat film having the following configuration, and have further completed the present invention based on such findings.

  A hard coat film according to an embodiment of the present invention is a hard coat film having a hard coat layer on a cellulose acetate film having an acetylation degree of 51.0% to 56.0%, and the cellulose acetate film is a sugar ester compound. The hard coat film has a pencil hardness of 2H or more and 7H or less (measured value based on JIS K5400).

  With such a configuration, first, the internal stress (residual stress) of the hard coat film is optimized by controlling the hardness of the hard coat layer, thereby improving the adhesion between the cellulose acetate film and the hard coat layer. I think that. Furthermore, by including a sugar ester compound in a cellulose acetate film having an acetylation degree of 51.0% to 56.0%, compatibility between the cellulose acetate film and the hard coat layer is improved (affinity is increased), Adhesion is further improved.

  The hard coat film according to the present embodiment is more preferable because the pencil hardness is 4H or more and 7H or less because adhesion and weather resistance are further improved.

  In the hard coat film according to this embodiment, the sugar ester compound is preferably represented by the following general formula (1).

(In the formula, R _{1 to} R ₈ represent a substituted or unsubstituted alkylcarbonyl group having 2 to 22 carbon atoms or a substituted or unsubstituted arylcarbonyl group having 2 to 22 carbon atoms, and R _{1 to} R _8. May be the same or different.) Thereby, a hard coat film having excellent adhesion can be obtained.

  Furthermore, the total average substitution degree of the sugar ester compound represented by the general formula (1) is more preferably 5.0 to 6.9.

  Preferably, the hard coat layer contains reactive silica fine particles (Xa) surface-treated with an organic compound having a polymerizable unsaturated group.

Further, the arithmetic average roughness Ra of the hard coat layer is 4 to 20 nm, and the ratio between the arithmetic average roughness Ra of the hard coat layer and the uneven average interval Sm of the hard coat layer coating surface of the cellulose acetate film (Ra / Sm) is preferably 2 × 10 ^{−4 to} 6 × 10 ⁻³ .

  Moreover, it is also preferable that the hard coat layer is an antiglare layer, and the ratio of the scattered reflectance to the integrated reflectance of the antiglare layer is 2 to 60%.

  In that case, the ratio of the scattering reflectance is more preferably 20 to 50%.

  Furthermore, it is also preferable that the hard coat layer is composed of two or more layers and the hard coat layer in contact with the base film contains an ultraviolet absorber.

  Moreover, the polarizing plate according to another embodiment of the present invention is a polarizing plate comprising a polarizing element and a transparent protective film disposed on the surface of the polarizing element, wherein the transparent protective film is the hard coat. It is characterized by being a film. According to such a configuration, as a transparent protective film for a polarizing element, there is no unevenness even in a high temperature and high humidity environment, and the adhesion is high. For example, when applied to a liquid crystal display device, the image quality of the liquid crystal display device is improved. -A polarizing plate capable of realizing high durability can be obtained.

  The liquid crystal display device according to another embodiment of the present invention is a liquid crystal display device including a liquid crystal cell and two polarizing plates arranged so as to sandwich the liquid crystal cell, the two polarizing plates. At least one of the plates is the polarizing plate. According to such a configuration, since a polarizing plate having high adhesion without unevenness is used even in a high temperature and high humidity environment, it is possible to realize high image quality and high durability of the liquid crystal display device.

  According to the present invention, by controlling the hardness of the hard coat layer, the internal stress (residual stress) of the hard coat film is optimized, and the acetylation degree is 51.0% to 56.0% with high moisture permeability. It is possible to provide a hard coat film with improved interlayer adhesion between the cellulose acetate and the hard coat layer, a production method thereof, and a polarizing plate and a liquid crystal display device using the hard coat film. Therefore, according to the present invention, a hard coat film excellent in adhesion can be obtained even after a weather resistance test (heat shock test and UV exposure test). Furthermore, by using the hard coat film, a polarizing plate and a liquid crystal display device excellent in unevenness and visibility can be provided.

FIG. 1 is a schematic view of an apparatus used for the contrast test of Example 1. 2 shows a photograph of actual observation results in the contrast test of Example 1. FIG. FIG. 3 shows a schematic cross-sectional view of the polarizing plate 201 produced in Example 4.

  Hereinafter, although the form for implementing this invention is demonstrated in detail, this invention is not limited to these.

  The hard coat film according to this embodiment is a hard coat film having a hard coat layer on a cellulose acetate film having an acetylation degree of 51.0% to 56.0%, and the cellulose acetate film contains a sugar ester compound. And the pencil hardness of a hard coat film is 2H or more and 7H or less by the measured value based on JISK5400.

<Cellulose acetate film>
(Sugar ester compound)
In the hard coat film according to the present embodiment, a cellulose acetate film containing a sugar ester compound and having an acetylation degree of 51.0% to 56.0% is used.

  In the present embodiment, the sugar ester compound is a compound obtained by esterifying all or part of the OH group of a sugar such as the following monosaccharide, disaccharide, trisaccharide or oligosaccharide. Examples of the sugar include glucose, galactose, mannose, fructose, xylose, arabinose, lactose, sucrose, nystose, 1F-fructosyl nystose, stachyose, maltitol, lactitol, lactulose, cellobiose, maltose, cellotriose, maltotriose, raffinose And kestose. In addition, gentiobiose, gentiotriose, gentiotetraose, xylotriose, galactosyl sucrose, and the like are also included. Among these compounds, compounds having a furanose structure and / or a pyranose structure are particularly preferable. Among these, sucrose, kestose, nystose, 1F-fructosyl nystose, stachyose and the like are preferable, and sucrose is more preferable. As oligosaccharides, maltooligosaccharides, isomaltooligosaccharides, fructooligosaccharides, galactooligosaccharides, and xylo-oligosaccharides can also be preferably used.

  The monocarboxylic acid used for esterifying the sugar is not particularly limited, and known aliphatic monocarboxylic acid, alicyclic monocarboxylic acid, aromatic monocarboxylic acid and the like can be used. The carboxylic acid to be used may be one kind or a mixture of two or more kinds. Preferred aliphatic monocarboxylic 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 , Saturated fatty acids such as 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, melicic acid, and laccelic acid And unsaturated fatty acids such as undecylenic acid, oleic acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid and octenoic acid. Examples of preferred alicyclic monocarboxylic acids include cyclopentane carboxylic acid, cyclohexane carboxylic acid, cyclooctane carboxylic acid, or derivatives thereof. Examples of preferred aromatic monocarboxylic acids include benzoic acid, aromatic monocarboxylic acids having an alkyl group or alkoxy group introduced into the benzene ring of benzoic acid, cinnamic acid, benzylic acid, biphenylcarboxylic acid, naphthalenecarboxylic acid, tetralin An aromatic monocarboxylic acid having two or more benzene rings, such as carboxylic acid, or a derivative thereof can be mentioned, and more specifically, xylic acid, hemelic acid, mesitylene acid, planicylic acid, γ-isojurylic acid, Julylic acid, mesitic acid, α-isoduric acid, cumic acid, α-toluic acid, hydroatropic acid, atropic acid, hydrocinnamic acid, salicylic acid, o-, m, p-anisic acid, creosote acid, o-, m, p-homosalicylic acid, o-pyrocatechuic acid, β-resorcylic acid, vanillic acid, isovanillic acid, veratrum , O- veratric acid, gallic acid, asarone acid, mandelic acid, homoanisic acid, homovanillic acid, homoveratric acid, o- homoveratric acid, Futaron acid, can be mentioned p- coumaric acid, especially benzoic acid. Among the ester compounds esterified, an acetyl compound into which an acetyl group has been introduced by esterification is preferable.

Although the specific example of the sugar ester compound which can be used in this embodiment below is shown, it is not limited to these.
Compound 1:

Compound 2:

Compound 3:

Compound 4:

Compound 5:

Compound 6:

Compound 7:

Compound 8:

Compound 9:

Compound 10:

Compound 11:

Compound 12:

Compound 13:

  Furthermore, as a sugar ester compound part, the compound shown by General formula (1) from the point which exhibits the effect of this invention favorably is preferable. Below, the compound shown by General formula (1) is demonstrated.

(In the formula, R _{1 to} R ₈ represent a substituted or unsubstituted alkylcarbonyl group having 2 to 22 carbon atoms or a substituted or unsubstituted arylcarbonyl group having 2 to 22 carbon atoms, and R _{1 to} R _8. May be the same or different.)
Although the compound shown by General formula (1) below is shown more concretely (compound 1-1-compound 1-23), it is not limited to these.

  The compound represented by the general formula (1) can be obtained, for example, by the following method.

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) is charged, and the temperature is raised while bubbling nitrogen gas from a nitrogen gas introduction tube with stirring, and an esterification reaction is 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 are distilled off. Then, 1 L of toluene and 300 g of a 0.5% by mass aqueous sodium carbonate solution are added, and the mixture is stirred at 50 ° C. for 30 minutes and then allowed to stand to separate the toluene layer. Finally, 100 g of water was added to the collected toluene layer, and after washing with water at room temperature for 30 minutes, the toluene layer was collected, and toluene was distilled off at 60 ° C. under reduced pressure (4 × 10 ² Pa or less). A mixture of the following exemplary compounds A-1, A-2, A-3, A-4 and A-5 is obtained.

  When the actually 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 mass%. Further, the obtained mixture is purified by column chromatography using silica gel to obtain exemplary compounds A-1, A-2, A-3, A-4 and A-5 having a purity of 100%, respectively. Can do.

  Among the compounds represented by the general formula (1), a compound having a total average substitution degree of 6.1 to 6.9 is preferable because the effects of the present invention are better exhibited even under more severe conditions. In the synthesis example shown above, the substitution degree distribution can be adjusted to the target substitution degree by adjusting the esterification reaction time or mixing compounds having different substitution degrees.

  When an ester compound composed of a monosaccharide or oligosaccharide is contained in a cellulose acetate film (hereinafter also simply referred to as a cellulose acetate film) having an acetylation degree of 51.0% to 56.0%, which will be described later, the acetylation degree is 51. It is preferable to contain 1 to 30% by mass, more preferably 5 to 25% by mass, and more preferably 5 to 20% by mass with respect to 0.0% to 56.0% cellulose acetate (hereinafter also simply referred to as cellulose acetate). % Content is particularly preferable.

(Cellulose acetate film substrate)
As the cellulose acetate film according to this embodiment, a film made of cellulose acetate having an acetylation degree X (%) satisfying the range of the following formula (III) is used from the viewpoint of permeability.

Formula (III) 51.0 ≦ X ≦ 56.0
A more preferable range of the acetylation degree X is 54.0 ≦ X ≦ 56.0.

The retardation R ₀ in the in-plane direction of the cellulose acetate film is defined by the following formula (I), preferably 30 nm or more, more preferably in the range of 30 to 200 nm, and in the range of 30 to 90 nm. Is more preferable. Retardation _{R th} in the thickness direction is defined by the following formula (II), preferably at 70nm or more, and more preferably in a range of 70 to 300 nm.

Formula (I) R _o = (nx−ny) × d
Formula (II) _Rth = {(nx + ny) / 2-nz} * d
(Where nx is the refractive index in the slow axis direction in the film plane, ny is the refractive index in the fast axis direction in the film plane, nz is the refractive index in the thickness direction of the film, and d is The thickness (nm) of the film.) The method of adjusting the retardation is not particularly limited, but a method of adjusting by stretching is common.

  The cellulose acetate in this embodiment can be synthesized by a known method. The cellulose as a raw material for cellulose acetate is not particularly limited, and examples thereof include cotton linters, wood pulp (derived from conifers and hardwoods), kenaf and the like. Moreover, the cellulose acetate obtained from them can be mixed and used in arbitrary ratios, respectively.

  Moreover, the cellulose acetate in this embodiment can also use a commercial item, and specifically, Daicel Corporation L20, L30, L40, L50, Eastman Chemical Co., Ltd. Ca398-3, Ca398-6, Ca398-10, Ca398. -30, Ca394-60S, etc. can be used.

  The cellulose acetate film according to this embodiment may be used in combination with other resins. Specifically, triacetyl cellulose, cellulose acetate propionate, cellulose acetate butyrate, polyethylene terephthalate, polyethylene naphthalate, polycarbonate resin, polyarylate resin, polysulfone (including polyethersulfone) resin, polyethylene resin, polypropylene resin, Cellophane, polyvinylidene chloride resin, polyvinyl alcohol, ethylene vinyl alcohol, syndiotactic polystyrene, norbornene resin, polymethylpentene, polyether ketone, polyether ketone imide, polyamide, fluororesin, nylon, cycloolefin, polymethyl methacrylate or acrylic However, it is not limited to these. As the resin that can be used in combination, cellulose acetate propionate is preferable from the viewpoint of compatibility. Specifically, when an acyl group having 2 to 4 carbon atoms is used as a substituent, the substitution degree of the acetyl group is X, and the substitution degree of the propionyl group is Y, the following formulas (I) and (II) are simultaneously What satisfies is preferable.

Formula (I) 1.9 ≦ X ≦ 2.5
Formula (II) 0.1 ≦ Y ≦ 0.9
In addition, the resin ratio when used in combination is not particularly limited as long as the objective effect of the present invention is obtained, but is preferably 100% by mass or less with respect to 100% by mass of the cellulose acetate according to the present invention.

The cellulose acetate film which concerns on this embodiment may contain the ester compound represented by following General formula (2) from the dimensional stability by an environmental change.
General formula (2) B- (GA) n-GB
(Wherein B is a hydroxy group or carboxylic acid residue, G is 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) , 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 1 or more.)
In the general formula (2), the alkylene glycol component having 2 to 12 carbon atoms includes ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 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-propanediol (neopentyl glycol), 2 , 2-diethyl-1,3-propanediol (3,3-dimethylolpentane), 2-n-butyl-2-ethyl-1,3-propanediol (3,3-dimethylolheptane), 3-methyl- 1,5-pentanediol 1,6-hexanediol, 2,2,4-trimethyl 1,3-pentanediol, 2-ethyl 1, -Hexanediol, 2-methyl 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecanediol, etc., and these glycols are one kind or two kinds or more Used as a mixture.

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

  Examples of the aryl glycol component having 6 to 12 carbon atoms include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol and the like, and these glycols can be used as one kind or a mixture of two or more kinds.

  Examples of the oxyalkylene glycol component having 4 to 12 carbon atoms include diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and tripropylene glycol. These glycols may be used alone or in combination of two or more. Can be used as a mixture.

  Examples of the alkylene dicarboxylic acid component having 4 to 12 carbon atoms include succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, and the like. Used as a mixture of two or more. 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.

  Although the specific example (compound 2-1-compound 2-23) of the ester compound represented by General formula (2) below is shown, it is not limited to this.

  In addition, when making the cellulose acetate film which concerns on this embodiment contain the ester compound represented by General formula (2), it is preferable to make it contain 1-50 mass% with respect to a cellulose acetate, 5-35 mass. % Is more preferable, and 5 to 25% by mass is particularly preferable.

(Other additives)
[Plasticizer]
The cellulose acetate film according to the present embodiment may contain a plasticizer as necessary.

  The plasticizer that can be used is not particularly limited, but polyvalent carboxylate plasticizer, glycolate plasticizer, phthalate ester plasticizer, fatty acid ester plasticizer, and polyhydric alcohol ester plasticizer, ester. And plasticizers such as acrylic plasticizers and acrylic plasticizers.

  The polyhydric alcohol ester plasticizer is a plasticizer comprising an ester of a divalent or higher aliphatic polyhydric alcohol and a monocarboxylic acid, and preferably has an aromatic ring or a cycloalkyl ring in the molecule. Preferably it is a 2-20 valent aliphatic polyhydric alcohol ester. Although the specific examples 1-35 of a polyhydric alcohol ester plasticizer are shown below, it is not limited to these.

  The glycolate plasticizer is not particularly limited, but alkylphthalylalkyl glycolates can be preferably used. Examples of alkyl phthalyl alkyl glycolates include methyl phthalyl methyl glycolate, ethyl phthalyl ethyl glycolate, propyl phthalyl propyl glycolate, butyl phthalyl butyl glycolate, octyl phthalyl octyl glycolate, methyl phthalyl ethyl Glycolate, ethyl phthalyl methyl glycolate, ethyl phthalyl propyl glycolate, methyl phthalyl butyl glycolate, ethyl phthalyl butyl glycolate, butyl phthalyl methyl glycolate, butyl phthalyl ethyl glycolate, propyl phthalyl butyl glycol Butyl phthalyl propyl glycolate, methyl phthalyl octyl glycolate, ethyl phthalyl octyl glycolate, octyl phthalyl methyl glycolate, octyl phthalate Ethyl glycolate, and the like.

  Examples of the phthalate ester plasticizer include diethyl phthalate, dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, dioctyl phthalate, dicyclohexyl phthalate, and dicyclohexyl terephthalate.

  Examples of the citrate plasticizer include acetyl trimethyl citrate, acetyl triethyl citrate, and acetyl tributyl citrate.

  Examples of fatty acid ester plasticizers include butyl oleate, methylacetyl ricinoleate, and dibutyl sebacate.

  Examples of the phosphate ester plasticizer include triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate and the like.

  The polyvalent carboxylic acid ester plasticizer is a compound composed of an ester of a divalent or higher, preferably a divalent to 20 valent polyvalent carboxylic acid and an alcohol.

  Specific examples of polyvalent carboxylic acid ester plasticizers include triethyl citrate, tributyl citrate, acetyl triethyl citrate (ATEC), acetyl tributyl citrate (ATBC), benzoyl tributyl citrate, acetyl triphenyl citrate, acetyl Examples include, but are not limited to, tribenzyl citrate, dibutyl tartrate, diacetyl dibutyl tartrate, tributyl trimellitic acid, tetrabutyl pyromellitic acid, and the like.

  In addition, when the plasticizer as described above is contained in the cellulose acetate film according to the present embodiment, the amount used is not uniform depending on the type of plasticizer, usage conditions, etc. The content is preferably 50% by mass, more preferably 5 to 35% by mass, and particularly preferably 5 to 25% by mass.

[Ultraviolet absorber]
The cellulose acetate film according to this embodiment may contain an ultraviolet absorber. Since the ultraviolet absorber absorbs ultraviolet rays of 400 nm or less, durability can be improved. In particular, the ultraviolet absorber preferably has a transmittance of 10% or less at a wavelength of 370 nm, more preferably 5% or less, and still more preferably 2% or less. Specific examples of the ultraviolet absorber are not particularly limited. For example, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, triazine compounds, nickel complex salts, inorganic powders. Examples include the body.

  More specifically, for example, 5-chloro-2- (3,5-di-sec-butyl-2-hydroxylphenyl) -2H-benzotriazole, (2-2H-benzotriazol-2-yl) -6 -(Linear and side chain dodecyl) -4-methylphenol, 2-hydroxy-4-benzyloxybenzophenone, 2,4-benzyloxybenzophenone, etc. can be used. Commercially available products may be used. For example, TINUVIN such as TINUVIN 109, TINUVIN 171, TINUVIN 234, TINUVIN 326, TINUVIN 327, and TINUVIN 328 manufactured by BASF Japan Ltd. can be preferably used.

  Preferred ultraviolet absorbers are benzotriazole ultraviolet absorbers, benzophenone ultraviolet absorbers, and triazine ultraviolet absorbers, and particularly preferred are benzotriazole ultraviolet absorbers and benzophenone ultraviolet 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.

  As the UV absorber, a polymer UV absorber can be preferably used, and a polymer type UV absorber is particularly preferably used.

  In addition, as a benzotriazole type ultraviolet absorber, TINUVIN 109 (octyl-3- [3-tert-butyl-4-hydroxy-5- (5-chloro-2H-benzoic acid) manufactured by BASF Japan KK is a commercially available product. A mixture of triazol-2-yl) phenyl] propionate and 2-ethylhexyl-3- [3-tert-butyl-4-hydroxy-5- (5-chloro-2H-benzotriazol-2-yl) phenyl] propionate), TINUVIN 928 (2- (2H-benzotriazol-2-yl) -6- (1-methyl-1-phenylethyl) -4- (1,1,3,3-tetramethylbutyl) phenol) is used. Can do.

  As the triazine-based ultraviolet absorber, TINUVIN 400 (2- (4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl) manufactured by BASF Japan Ltd., which is a commercial product, is used. ) -5-hydroxyphenyl and oxirane reaction product), TINUVIN 460 (2,4-bis [2-hydroxy-4-butoxyphenyl] -6- (2,4-dibutoxyphenyl) -1,3- 5-triazine), TINUVIN 405 (2- (2,4-dihydroxyphenyl) -4,6-bis- (2,4-dimethylphenyl) -1,3,5-triazine and (2-ethylhexyl) -glycidic acid Ester reaction products) and the like can be used.

  The ultraviolet absorber is added by dissolving the ultraviolet absorber in an alcohol, such as methanol, ethanol, butanol or the like, an organic solvent such as methylene chloride, methyl acetate, acetone, dioxolane, or a mixed solvent thereof, and then becomes a film substrate. It may be added to the resin solution (dope) or directly during the 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 acetate to disperse and then added to the dope.

  The amount of the UV absorber used is not uniform depending on the type of UV absorber, the operating conditions, etc., but when the dry film thickness of the cellulose acetate film is 30 to 200 μm, it is 0.5 to 10 with respect to the cellulose acetate film. % By mass is preferable, and 0.6 to 4% by mass is more preferable.

〔Antioxidant〕
The cellulose acetate film in the present embodiment may further contain an antioxidant (deterioration inhibitor).

  When a liquid crystal image display device or the like is placed in a high humidity and high temperature state, the cellulose acetate film may be deteriorated. The antioxidant has a role of delaying or preventing the cellulose acetate film from being decomposed by, for example, a residual solvent amount of halogen in the cellulose acetate film or phosphoric acid of a phosphoric acid plasticizer.

  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 10000 ppm, more preferably 10 to 1000 ppm in terms of mass ratio with respect to the cellulose acetate film.

[Fine particles]
In order to improve the handleability, the cellulose acetate film according to the present embodiment has, for example, silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, kaolin, talc, calcined calcium silicate, hydrated calcium silicate, silica It is preferable to contain matting agents such as inorganic fine particles such as aluminum oxide, magnesium silicate, and calcium phosphate, and a crosslinked polymer. Among these, silicon dioxide is preferably used because it can reduce the haze of the cellulose acetate film.

  The primary average particle diameter of the fine particles is preferably 20 nm or less, more preferably 5 to 16 nm, and particularly preferably 5 to 12 nm.

  These fine particles preferably form secondary particles having a particle size of 0.1 to 5 μm and are contained in the cellulose acetate film, and the more preferable average particle size is 0.1 to 2 μm, particularly preferably 0.2. ~ 0.6 μm. Thereby, the unevenness | corrugation about 0.1-1.0 micrometer high can be formed in the film surface, and this can give appropriate slipperiness to the film surface. The primary average particle diameter of the fine particles is measured by observing the particles with a transmission electron microscope (magnification of 500,000 to 2,000,000 times), observing 100 particles, measuring the particle diameter, and using the average value to obtain the primary value. The average particle size was taken.

  The apparent specific gravity of the fine particles is preferably 70 g / liter or more, more preferably 90 to 200 g / liter, and particularly preferably 100 to 200 g / liter. A higher apparent specific gravity is preferable because a high-concentration dispersion can be produced, and haze and aggregates are improved.

  Silicon dioxide which is a fine particle preferably used is commercially available under the trade names of, for example, Aerosil 200V and Aerosil R972V (manufactured by Nippon Aerosil Co., Ltd.), and these can be used.

  The apparent specific gravity described above is calculated by the following equation by taking a certain amount of silicon dioxide fine particles in a graduated cylinder and measuring the weight at this time.

Apparent specific gravity (g / liter) = silicon dioxide mass (g) / volume of silicon dioxide (liter)
《Distribution method》
Next, a method for dispersing fine particles will be described using silicon dioxide as an example. The concentration of silicon dioxide when the silicon dioxide fine particles are mixed with a solvent and dispersed is preferably 5% by mass to 30% by mass, more preferably 10% by mass to 25% by mass, and most preferably 15% by mass to 20% by mass. A higher dispersion concentration is preferable because liquid turbidity with respect to the added amount tends to be low, and haze and aggregates are improved.

  Examples of the solvent used include lower alcohols, and preferred specific examples include methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol and the like. Although it does not specifically limit as solvents other than a lower alcohol, It is preferable to use the same kind of solvent as the solvent used at the time of film formation of a cellulose acetate.

  The amount of fine particles added to the cellulose acetate film varies depending on the type of fine particles. For example, when silicon dioxide is taken as an example, the silicon dioxide fine particles are preferably 0.01 to 5.0% by mass with respect to cellulose acetate. 0.05-1.0 mass% is still more preferable, and 0.1-0.5 mass% is the most preferable. When the addition amount is large, the coefficient of dynamic friction is excellent, and when the addition amount is small, aggregates are reduced.

  For dispersion of the fine particles, a normal disperser such as a ball mill or a sand mill can be used.

  In addition, casting a dope containing fine particles so as to be in direct contact with the casting support is preferable because a film having high slip properties and low haze can be obtained.

  In the cellulose acetate film, the total amount of calcium and magnesium and the amount of acetic acid preferably satisfy the following relational expression (a).

Relational expression (a): 1 ≦ (acetic acid amount) / (total amount of calcium and magnesium) ≦ 30
Calcium and magnesium are contained in cellulose, which is a raw material for cellulose acetate film, but neutralize and stabilize the acid catalyst (especially sulfuric acid) added to the cellulose production process. It may be added as a metal salt (inorganic acid salt, organic acid salt). Moreover, you may add as a metal oxide, a metal hydroxide, and a metal salt (inorganic acid salt, organic acid salt) at the time of film formation of a cellulose acetate film. The total amount of calcium and magnesium refers to their total amount. The amount of acetic acid refers to the total amount of residual acetic acid and free acetic acid.

  After casting, the film is peeled off, dried and wound into a roll, and then a functional thin film such as a hard coat layer is provided. Until processing or shipment, packaging is usually performed in order to protect the product from dirt, static electricity, and the like.

  The packaging material is not particularly limited as long as the above purpose can be achieved, but a material that does not hinder volatilization of the residual solvent from the film is preferable. Specific examples include polyethylene, polyester, polypropylene, nylon, polystyrene, paper, various non-woven fabrics, and the like. Those in which the fibers are mesh cloth are more preferably used.

(Method for producing cellulose acetate film)
Next, the manufacturing method of the cellulose acetate film which concerns on this invention is demonstrated.

  The cellulose acetate film according to the present invention can be preferably used whether it is a film produced by a solution casting method or a film produced by a melt casting method.

  Manufacturing by the solution casting method involves preparing a dope by dissolving cellulose acetate and an additive in a solvent, casting a dope on an endless metal support that moves infinitely, and casting the cast dope into a web. As a drying process, a peeling process from a metal support, a stretching or width holding process, a further drying process, and a winding process of a finished film.

  The process for preparing the dope will be described. The concentration of cellulose acetate 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 acetate is too high, the load during filtration increases and the filtration accuracy is poor. Become. As a density | concentration which makes these compatible, 10-35 mass% is preferable, More preferably, it is 15-25 mass%.

  The solvent used in the dope may be used alone or in combination of two or more. However, it is preferable to use a mixture of a good solvent and a poor solvent of cellulose acetate in terms of production efficiency, and there are many good solvents. This is preferable from the viewpoint of solubility of cellulose acetate.

  The preferable range of the mixing ratio of the good solvent and the poor solvent is 70 to 98% by mass for the good solvent and 2 to 30% by mass for the poor solvent. With a good solvent and a poor solvent, what dissolve | melts the cellulose acetate to be used independently is defined as a good solvent, and what does not swell or dissolve independently is defined as a poor solvent.

  Therefore, a good solvent and a poor solvent change with the average acetylation degree (acetyl group substitution degree) of a cellulose acetate.

  The good solvent is not particularly limited, and examples thereof include organic halogen compounds such as methylene chloride, dioxolanes, acetone, methyl acetate, and methyl acetoacetate. Particularly preferred is methylene chloride or methyl acetate.

  Although it does not specifically limit as a poor solvent, For example, methanol, ethanol, n-butanol, cyclohexane, cyclohexanone etc. are used preferably. Moreover, it is preferable that 0.01-2 mass% of water contains in dope.

  Moreover, the solvent used for melt | dissolution of a cellulose acetate collect | recovers the solvent removed from the film by drying at the film-forming process, and uses this again.

  The recovery solvent may contain trace amounts of additives added to cellulose acetate, such as plasticizers, UV absorbers, polymers, monomer components, etc., but these are preferably reused even if they are included. Can be purified and reused if necessary.

  As a method for dissolving cellulose acetate when preparing the dope described above, a general method can be used. 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 mamacos.

  Further, a method in which cellulose acetate is mixed with a poor solvent and wetted or swollen, and then a good solvent is added and dissolved is also preferably used.

  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 cellulose acetate, 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 cellulose acetate can be dissolved in a solvent such as methyl acetate.

  Next, this cellulose acetate 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, but there is a problem that the filter medium is likely to be clogged if the absolute filtration accuracy is too small.

  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 acetate by filtration.

Bright spot foreign matter means that when two polarizing plates are placed in a crossed Nicol state, an optical film or the like is placed between them, light is applied from one polarizing plate side, and observation is performed from the other polarizing plate side. 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 / cm < 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. As the metal support, a stainless steel belt or a drum whose surface is plated with a casting is preferably used.

  The cast width can be 1 to 4 m. The surface temperature of the metal support in the casting step is −50 ° C. to a temperature lower than the boiling point of the solvent, and a higher temperature is preferable because the web can be dried faster. May deteriorate.

  A preferable support temperature is 0 to 55 ° C, and more preferably 25 to 50 ° 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 hot 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 warm air is used, wind at a temperature higher than the target temperature may be used.

  In order for the cellulose acetate 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 amount of residual solvent is defined by the following formula.

Residual solvent amount (% by mass) = {(MN) / N} × 100
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 step of the cellulose acetate film, the web is peeled off from the metal support, and further dried, and the residual solvent amount is preferably 1% by mass or less, more preferably 0.1% by mass or less, Especially preferably, it is 0-0.01 mass% or less.

  In casting, co-casting can be used, and the cellulose acetate film according to the present invention may be a film laminated in two or more layers by a production method such as co-casting.

  In the film drying step, generally, a roll drying method (a method in which webs are alternately passed through a plurality of rolls arranged above and below) and a method in which the web is dried while being conveyed by a tenter method are employed.

  In order to produce the cellulose acetate film according to the present invention, it is particularly preferable to perform stretching in the width direction (lateral direction) by a tenter method in which both ends of the web are held with clips or the like. Peeling is preferably performed at a peeling tension of 300 N / m or less.

  The means for drying the web is not particularly limited, and can be generally performed with hot air, infrared rays, a heating roll, microwave, or the like, but it is preferably performed with hot air in terms of simplicity.

  The drying temperature in the web drying step is preferably increased stepwise from 40 to 200 ° C.

  Although the film thickness of a cellulose acetate film is not specifically limited, 10-200 micrometers is used. In particular, the film thickness is particularly preferably 10 to 100 μm. More preferably, it is 20-60 micrometers.

  The cellulose acetate film according to the present invention has a width of 1 to 4 m. In particular, those having a width of 1.4 to 4 m are preferably used, and particularly preferably 1.6 to 3 m. If it exceeds 4 m, conveyance becomes difficult.

  In addition, the cellulose acetate film according to the present invention can be biaxially or uniaxially stretched sequentially or simultaneously with respect to the longitudinal direction (film forming direction) and the direction perpendicular to the film plane, that is, the width direction. The stretching ratio in the biaxial direction is preferably 0.8 to 1.5 times in the longitudinal direction and 1.1 to 2.5 times in the width direction, and 0.8 to 1.0 times in the longitudinal direction. More preferably, it is performed in the range of 1.2 to 2.0 times in the width direction. The stretching temperature is preferably 120 ° C. to 200 ° C., more preferably 150 ° C. to 200 ° C., and more preferably 150 ° C. to 190 ° C. or less. The residual solvent in the film is preferably 20 to 0%, more preferably 15 to 0%.

  Specifically, it is preferable that the residual solvent is stretched by 11% at 155 ° C., or the residual solvent is stretched by 2% at 155 ° C. Alternatively, it is preferable that the residual solvent is stretched at 11% at 160 ° C, or the residual solvent is stretched at less than 1% at 160 ° C.

  There is no particular limitation on the method of stretching the web. For example, a method in which a difference in peripheral speed is applied to a plurality of rolls, and the roll peripheral speed difference is used to stretch in the longitudinal direction between the rolls. And a method of stretching in the vertical direction, a method of stretching in the horizontal direction and stretching in the horizontal direction, a method of stretching in the vertical and horizontal directions and stretching in both the vertical and horizontal directions. Of course, these methods may be used in combination.

  In the case of the so-called tenter method, driving the clip portion by the linear drive method is preferable because smooth stretching can be performed and the risk of breakage and the like can be reduced.

  These width maintenance or lateral stretching in the film forming step is preferably performed by a tenter, and may be a pin tenter or a clip tenter.

  When the slow axis or the fast axis of the cellulose acetate film is present in the film plane and the angle formed with the film forming direction is θ1, θ1 is preferably −1 ° or more and + 1 ° or less, −0.5 ° More preferably, it is + 0.5 ° or less.

This θ1 can be defined as an orientation angle, and θ1 can be measured using an automatic birefringence meter KOBRA-21ADH (Oji Scientific Instruments). Each of θ1 satisfying the above relationship can contribute to obtaining high luminance in a display image, suppressing or preventing light leakage, and contributing to obtaining faithful color reproduction in a liquid crystal display device.
(Physical properties of cellulose acetate film)
The moisture permeability of the cellulose acetate film according to the present embodiment, 40 ° C., preferably 300~1800g ^/ m 2 · 24h at 90% RH, preferably more ^{400~1500g / m 2 · 24h, 40~1300g} / m 2 · 24h is particularly preferred. The moisture permeability can be measured according to the method described in JIS Z 0208. The cellulose acetate film according to this embodiment preferably has a breaking elongation of 10 to 80%, and more preferably 20 to 50%.

  The visible light transmittance of the cellulose acetate film according to this embodiment is preferably 90% or more, and more preferably 93% or more.

  The haze of the cellulose acetate film according to the present embodiment is preferably less than 1%, particularly preferably 0 to 0.1% per film.

  Moreover, you may obtain the retardation value over a wider range by apply | coating a liquid-crystal layer further to a cellulose acetate film.

<Hard coat film>
The hard coat film according to the present embodiment is composed of at least a hard coat layer and the cellulose acetate film described above, and the hard coat film has a pencil hardness of 2H or more and 7H or less. Preferably, the pencil hardness is 4H or more and 7H or less. By appropriately adjusting the composition of the hard coat layer (base resin, additives, blending ratio thereof, etc.) and film thickness so that the pencil hardness of the hard coat film is adjusted to the specific range as described above, The adhesion between the cellulose acetate film and the hard coat layer is very good. In this embodiment, the pencil hardness is conditioned at a temperature of 23 ° C. and a relative humidity of 55% for 2 hours or more, and then, using a test pencil defined by JIS S 6006, JIS K 5400 It is a value measured according to the pencil hardness test method specified.

(Hard coat layer)
Next, the hard coat layer composition for forming the hard coat layer will be described. In the present embodiment, the hard coat layer composition for forming the hard coat layer is not particularly limited as long as the pencil hardness of the hard coat film is 2H or more and 7H or less.

  The hardness of the hard coat film is determined by the composition of the hard coat composition for forming the hard coat layer (base resin, additives, blending ratio thereof, etc.), the manufacturing method of the hard coat layer, the thickness of the hard coat layer, etc. It can adjust by adjusting suitably.

  Hereinafter, the configuration and manufacturing method of the hard coat layer according to the present embodiment will be described in more detail with preferred specific examples.

[Active energy ray-curable resin]
Since the hard coat layer of the hard coat film according to this embodiment is preferably composed of, for example, an active energy ray curable resin, the hard coat layer composition in this embodiment includes an active energy ray curable resin. It is preferred that The active energy ray curable type refers to a resin that is cured through a crosslinking reaction or the like by irradiation with active rays such as ultraviolet rays or electron beams, and specifically, a resin having an ethylenically unsaturated group. More specifically, an ultraviolet curable urethane acrylate resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, an ultraviolet curable epoxy resin, or the like is preferably used. Of these, ultraviolet curable acrylate resins are preferred.

  As the ultraviolet curable acrylate resin, a polyfunctional acrylate is preferable. The polyfunctional acrylate is preferably selected from the group consisting of pentaerythritol polyfunctional acrylate, dipentaerythritol polyfunctional acrylate, pentaerythritol polyfunctional methacrylate, and dipentaerythritol polyfunctional methacrylate. Here, the polyfunctional acrylate is a compound having two or more acryloyloxy groups or methacryloyloxy groups in the molecule.

  Examples of the polyfunctional acrylate monomer include ethylene glycol diacrylate, diethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, and tetramethylolmethane triacrylate. , Tetramethylolmethane tetraacrylate, pentaglycerol triacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, glycerol triacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol Lithol hexaacrylate, tris (acryloyloxyethyl) isocyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, Tetramethylol methane trimethacrylate, tetramethylol methane tetramethacrylate, pentaglycerol trimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, glycerol trimethacrylate, dipentaerythritol trimethacrylate, dipentaerythritol tetramethacrylate Acrylate, dipentaerythritol penta methacrylate, dipentaerythritol hexa methacrylate, etc. isocyanurate derivatives of the active energy ray-curable are preferably exemplified. Commercially available products may be used as these polyfunctional acrylates, such as pentaerythritol tri / tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., A-TMM-3L), pentaerythritol triacrylate (manufactured by Kyoeisha Chemical Co., Ltd., PE-3A). Etc. can be obtained. In addition, these compounds are used individually or in mixture of 2 or more types, respectively.

  The isocyanurate derivative of the active energy ray-curable resin is not particularly limited as long as it has a structure in which one or more ethylenically unsaturated groups are bonded to the isocyanuric acid skeleton, but there are three in the same molecule. Compounds having the above ethylenically unsaturated groups and one or more isocyanurate rings are preferred.

  A commercial item can also be used as such an isocyanuric acid triacrylate compound, for example, Shin-Nakamura Chemical Co., Ltd. A-9300 etc. are mentioned. As a commercial item of an isocyanuric acid diacrylate compound, Toagosei Co., Ltd. Aronix M-215 etc. are mentioned, for example. Examples of the mixture of the isocyanuric acid triacrylate compound and the isocyanuric acid diacrylate compound include Aronix M-315 and Aronix M-313 manufactured by Toagosei Co., Ltd. As the ε-caprolactone-modified active energy ray-curable isocyanurate derivative, A-9300-1CL manufactured by Shin-Nakamura Chemical Co., Ltd., which is ε-caprolactone-modified tris- (acryloxyethyl) isocyanurate, manufactured by Toagosei Co., Ltd. Examples include Aronix M-327, but are not limited thereto.

  A monofunctional acrylate may be used as the active energy ray-curable resin. Monofunctional acrylates include isobornyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, isostearyl acrylate, benzyl acrylate, ethyl carbitol acrylate, phenoxyethyl acrylate, lauryl acrylate, isooctyl acrylate, tetrahydrofurfuryl acrylate, behenyl Examples include acrylate, 4-hydroxybutyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and cyclohexyl acrylate. Monofunctional acrylates can be obtained from Shin Nakamura Chemical Co., Ltd., Osaka Organic Chemical Industry Co., Ltd., and the like. These compounds are used alone or in admixture of two or more. Moreover, oligomers, such as a dimer and a trimer of the said monomer, may be sufficient.

  Further, urethane acrylate may be used as the active energy ray curable resin. As urethane acrylate, for example, commercially available products such as Beam Set 575CB manufactured by Arakawa Chemical Industries, Ltd. and UA-306H manufactured by Kyoeisha Chemical Co., Ltd. can be used.

  The viscosity of the polyfunctional acrylate as described above is preferably 3000 mPa · s or less, more preferably 1500 mPa · s or less, at 25 ° C. Particularly preferably, it is 1000 mPa · s or less. Examples of such low viscosity resins include glycerin triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate and the like. In addition, the said viscosity is the value measured on 25 degreeC conditions using the E-type viscosity meter.

  The compounding amount of the active energy ray-curable resin in the hard coat layer composition is usually 10 to 99 parts by mass, preferably 35 to 99 parts by mass when the entire composition is 100 parts by mass. When the blending amount of the active energy ray-curable resin is small, it is difficult to sufficiently obtain the film strength of the hard coat layer. Moreover, when there are many compounding quantities, since malfunctions, such as a film thickness uniformity at the time of apply | coating with the well-known coating method mentioned later and an application | coating stripe | line | muscle generate | occur | produce, it is unpreferable.

[Cationically polymerizable compound]
The hard coat layer may further contain a cationically polymerizable compound, and any cationic polymerizable compound can be used as long as it undergoes cationic polymerization by energy active ray irradiation or heat to form a resin. Specific examples include an epoxy group, a cyclic ether group, a cyclic acetal group, a cyclic lactone group, a cyclic thioether group, a spiro orthoester compound, and a vinyloxo group. Among them, a compound having a functional group such as an epoxy group or a vinyl ether group is preferably used in the present invention. Examples of the cationically polymerizable compound having an epoxy group or a vinyl ether group include phenyl glycidyl ether, ethylene glycol diglycidyl ether, glycerin diglycidyl ether, vinylcyclohexene dioxide, limonene dioxide, 3,4-epoxycyclohexylmethyl-3 ′. , 4'-epoxycyclohexanecarboxylate, bis- (6-methyl-3,4-epoxycyclohexyl) adipate, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, diethylene glycol divinyl ether, polyethylene glycol divinyl ether, 1 , 4-cyclohexanedimethanol divinyl ether and the like. Moreover, a polymer compound can also be used as an epoxy compound.

  When the cationic polymerizable compound is contained in the hard coat layer composition, the amount of the cationic polymerizable compound in the hard coat layer composition is usually 1 to 90 parts by mass when the entire composition is 100 parts by mass. The amount is preferably 1 to 50 parts by mass.

[Fine particles]
The hard coat layer may contain fine particles. Examples of the fine particles include inorganic fine particles and organic fine particles. As inorganic particles, silica, titanium oxide, aluminum oxide, tin oxide, indium oxide, ITO, zinc oxide, zirconium oxide, magnesium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated Mention may be made of calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate. As organic particles, polymethacrylic acid methyl acrylate resin powder, acrylic styrene resin powder, polymethyl methacrylate resin powder, silicon resin powder, polystyrene resin powder, polycarbonate resin powder, benzoguanamine resin powder, melamine resin powder, Examples thereof include polyolefin resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, and polyfluorinated ethylene resin powder. The average particle diameter of these fine particles is preferably 30 nm to 200 nm from the stability and clearness of the hard coat layer coating composition. The hard coat layer may contain two or more kinds of fine particles having different particle sizes. From the viewpoint of easily achieving the pencil hardness, the hard coat layer preferably contains silica fine particles.

  Moreover, it is preferable to make the hard coat layer contain reactive silica fine particles (Xa) surface-treated with an organic compound having a polymerizable unsaturated group, from the viewpoint of better exhibiting the effects of the present invention. Hereinafter, the reactive silica fine particles (Xa) surface-treated with an organic compound having a polymerizable unsaturated group will be described.

<< Reactive Silica Fine Particles (Xa) >>
Known silica fine particles can be used. The shape may be spherical or irregular, and is not limited to normal colloidal silica, and may be hollow particles, porous particles, core / shell particles, etc., but the pH is 2.0-6. .5 colloidal silica is preferred.

  The dispersion medium of the silica fine particles is preferably water or an organic solvent. Examples of organic solvents include alcohols such as methanol, isopropyl alcohol, ethylene glycol, butanol and ethylene glycol monopropyl ether; ketones such as methyl ethyl ketone and methyl isobutyl ketone; aromatic hydrocarbons such as toluene and xylene; dimethylformamide and dimethyl Examples include amides such as acetamide and N-methylpyrrolidone; esters such as ethyl acetate, butyl acetate and γ-butyrolactone; and organic solvents such as ethers such as tetrahydrofuran and 1,4-dioxane. Of these, alcohols and ketones are preferred. These organic solvents can be used alone or in combination as a dispersion medium. As a commercial item, Nissan Chemical Industry Co., Ltd. MEK-ST-L, MEK-ST-MS, IPA-ST-L, IPA-ST-ZL etc. can be mentioned as colloidal silica, for example.

  The reactive silica fine particles (Xa) are obtained by surface-treating the colloidal silica as described above with an organic compound having a polymerizable unsaturated group (hereinafter referred to as “organic compound (X)”). The organic compound (X) has a polymerizable unsaturated group, preferably an ethylenically unsaturated group, and further has a group represented by the following general formula (a) and a compound having a silanol group in the molecule or a silanol group by hydrolysis. It is preferable that it is a compound to be formed.

  Specifically, [—U—C (═V) —NH—] includes [—O—C (═O) —NH—], [—O—C (═S) —NH—], [— S—C (═O) —NH—], [—NH—C (═O) —NH—], [—NH—C (═S) —NH—], and [—S—C (═S). -NH-]. These groups can be used alone or in combination of two or more. Among these, from the viewpoint of thermal stability, a [—O—C (═O) —NH—] group and a [—O—C (═S) —NH—] group or [—S—C (═O) — It is preferable to use in combination with at least one of the NH— groups.

  Although there is no restriction | limiting in particular as an ethylenically unsaturated group contained in organic compound (X), For example, an acryloyl group, a methacryloyl group, and a vinyl group can be mentioned as a suitable example. This ethylenically unsaturated group is a structural unit that undergoes addition polymerization with active radical species.

  Examples of the compound that generates a silanol group include compounds in which an alkoxy group, an aryloxy group, an acetoxy group, an amino group, a halogen atom, and the like are bonded to a silicon atom, but an alkoxy group or an aryloxy group is bonded to a silicon atom. The compound thus obtained, that is, an alkoxysilyl group-containing compound or an aryloxysilyl group-containing compound is preferred. Specific examples include compounds represented by the following general formula (b).

In the general formula (b), R ²¹ and R ²² may be the same or different, and are a hydrogen atom, an alkyl group having 1 to 8 carbon atoms or an aryl group, for example, methyl, ethyl, propyl, butyl, octyl , Phenyl, xylyl group and the like. Here, j is an integer of 1 to 3.

Examples of the group represented by [(R ²¹ O) _j R ²² _3-j Si—] include a trimethoxysilyl group, a triethoxysilyl group, a triphenoxysilyl group, a methyldimethoxysilyl group, and a dimethylmethoxysilyl group. Can be mentioned. Of these groups, a trimethoxysilyl group or a triethoxysilyl group is preferable.

R ²³ is a divalent organic group having an aliphatic or aromatic structure having 1 to 12 carbon atoms, and may include a chain, branched, or cyclic structure. Specific examples include methylene, ethylene, propylene, butylene, hexamethylene, cyclohexylene, phenylene, xylylene, dodecamethylene and the like.

R ²⁴ is a divalent organic group, and is usually selected from divalent organic groups having a molecular weight of 14 to 10,000, preferably a molecular weight of 76 to 500. Specific examples include a chain polyalkylene group such as hexamethylene, octamethylene, and dodecamethylene; an alicyclic or polycyclic divalent organic group such as cyclohexylene and norbornylene; and 2 such as phenylene, naphthylene, biphenylene, and polyphenylene. Valent aromatic group; and these alkyl group-substituted and aryl group-substituted products. These divalent organic groups may contain an atomic group containing an element other than carbon and hydrogen atoms, and may contain a polyether bond, a polyester bond, a polyamide bond, and a polycarbonate bond.

R ²⁵ is a (k + 1) -valent organic group, and is preferably selected from a chain, branched or cyclic saturated hydrocarbon group and unsaturated hydrocarbon group.

  Z represents a monovalent organic group having a polymerizable unsaturated group in the molecule that undergoes an intermolecular crosslinking reaction in the presence of an active radical species. K is preferably an integer of 1 to 20, more preferably an integer of 1 to 10, and particularly preferably an integer of 1 to 5.

  The organic compound (X) is, for example, one or more compounds selected from a hydrolyzable silane, a polyisocyanate compound, a polythioisocyanate compound, and a compound having both an isocyanate group and a thioisocyanate group, and an isocyanate group or a thioisocyanate. It can be carried out by direct addition reaction of the active hydrogen-containing polymerizable unsaturated compound having an active hydrogen atom that causes an addition reaction with the group.

  Preferably, mercaptopropyltrimethoxysilane and isophorone diisocyanate are mixed in the presence of dibutyltin dilaurate and reacted at 60 to 70 ° C. for several hours, then pentaerythritol triacrylate is added, and further at 60 to 70 ° C. for several hours. React to a certain extent.

  Next, the obtained organic compound (X) is mixed with silica fine particles, hydrolyzed, and the two are combined to produce reactive silica fine particles (Xa).

  The amount of the organic compound (X) bonded to the silica fine particles is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, particularly preferably 1% by mass or more, based on 100% by mass of the silica fine particles. It is.

  If it is the said range, the dispersibility of the reactive silica fine particle (Xa) in a composition will be favorable. Moreover, the compounding ratio of the silica fine particles in the raw material during the production of the reactive silica fine particles (Xa) is preferably 5 to 99% by mass, and more preferably 10 to 98% by mass. The content of the reactive silica fine particles (Xa) in the hard coat layer coating composition is preferably 5 to 80% by mass, and preferably 10 to 80% by mass when the total solid content in the composition is 100% by mass. % Is more preferable. By using in such a range, it exists stably in a hard-coat coating composition.

  The hard coat layer preferably contains the above-mentioned active energy ray-curable resin and fine particles, and the active energy ray-curable resin: fine particles = 90: 10 to 20:80 in terms of the mass ratio.

[Other additives, manufacturing method of hard coat layer]
The hard coat layer preferably further contains a photopolymerization initiator in order to accelerate the curing of the active energy ray-curable resin. As a compounding quantity of a photoinitiator, it is preferable to contain by mass ratio with photoinitiator: active energy ray hardening-type resin = 20: 100-0.01: 100.

  Specific examples of the photopolymerization initiator include alkylphenone series, acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and derivatives thereof, but are not particularly limited thereto. It is not a thing. Commercially available products may be used, and preferred examples include Irgacure 184, Irgacure 907, and Irgacure 651 manufactured by BASF Japan.

  Moreover, it is preferable that the hard-coat layer contains the ultraviolet absorber similar to the ultraviolet absorber contained in the above-mentioned cellulose acetate film.

  Furthermore, the hard coat layer is composed of two or more layers, and the hard coat layer in contact with the base film contains an ultraviolet absorber, so that the object effect of the present invention can be satisfactorily exhibited, and the film of the hard coat layer This is preferable from the viewpoint of obtaining good strength (abrasion resistance) and pencil hardness. As content, it is preferable to contain by mass ratio, ultraviolet absorber: hard-coat layer composition = 0.01: 100-10: 100.

  When two or more hard coat layers are provided, the thickness of the hard coat layer in contact with the base film is preferably in the range of 0.05 to 2 μm. Two or more layers may be formed as a simultaneous multilayer. The simultaneous multi-layer is to form a hard coat layer by applying two or more hard coat layers on a base material without going through a drying step. In order to laminate the second hard coat layer on the first hard coat layer without a drying process, the layers are stacked one after another by an extrusion coater or simultaneously by a slot die having a plurality of slits. Can be done.

  In addition, as a method for preparing the hard coat layer, a hard coat layer coating composition diluted with a solvent that swells or partially dissolves the cellulose acetate film is applied, dried and cured on the cellulose acetate film by the following method. The method is preferable from the viewpoint that interlayer adhesion between the hard coat layer and the cellulose acetate film is easily obtained.

  As the solvent for swelling or partially dissolving the cellulose acetate film, a solvent containing a ketone and / or acetate is preferable. Specifically, examples of the ketone include methyl ethyl ketone, acetone, and cyclohexanone. Examples of the acetate ester include ethyl acetate, methyl acetate, and butyl acetate. The hard coat layer coating composition may contain an alcohol solvent as another solvent.

  The coating amount is preferably from 0.1 to 40 μm, more preferably from 0.5 to 30 μm, as the wet film thickness. The dry film thickness is preferably about 5 to 20 μm, and preferably 7 to 12 μm.

  The hard coat layer is a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die (extrusion) coater, a hard coat coating composition that forms a hard coat layer is applied using a known coating method such as an inkjet method, After application, the film can be dried, irradiated with actinic radiation (also referred to as UV curing treatment), and further subjected to heat treatment after UV curing as necessary. The heat treatment temperature after UV curing is preferably 80 ° C. or higher, more preferably 100 ° C. or higher, and particularly preferably 120 ° C. or higher. By performing the heat treatment after UV curing at such a high temperature, the mechanical strength (rubbing resistance, pencil hardness) of the hard coat layer becomes better.

  Drying is preferably performed by high-temperature treatment in which the temperature of the decreasing rate drying section is 80 ° C. or higher. More preferably, the temperature in the decreasing rate drying section is 95 ° C. or higher and 130 ° C. or lower. By setting the temperature of the rate-decreasing drying section to a high temperature treatment, convection occurs in the coating resin during the formation of the hard coat layer. As a result, fine surface roughness tends to appear on the hard coat layer surface, and the arithmetic described later The average roughness Ra is also preferable because it is easy to obtain.

  In general, it is known that the drying process changes from a constant state to a gradually decreasing state when drying starts. The decreasing section is called the decreasing rate drying section. In the constant rate drying section, the amount of heat flowing in is all consumed for solvent evaporation on the coating film surface, and when the solvent on the coating film surface decreases, the evaporation surface moves from the surface to the inside and enters the decreasing rate drying section. Thereafter, the temperature of the coating film surface rises and approaches the hot air temperature, so that the temperature of the ultraviolet curable resin composition rises, the resin viscosity decreases, and the fluidity increases.

  As a light source for UV curing treatment, any light source that generates ultraviolet rays can be used without limitation. 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.

Irradiation conditions vary depending on each lamp, but the irradiation amount of active rays is usually 50 to 1000 mJ / cm ² , preferably 50 to 300 mJ / cm ² .

  Moreover, when irradiating actinic radiation, it is preferable to carry out while applying tension | tensile_strength in the conveyance direction of a film, More preferably, it is performing applying tension | tensile_strength also in the width direction. The tension to be applied is usually 30 to 500 N / m, preferably 30 to 300 N / m. The method for applying tension is not particularly limited, and tension may be applied in the transport direction on the back roll, or tension may be applied in the width direction or biaxial direction by a tenter. Thereby, a film having further excellent flatness can be obtained.

  The hard coat layer may contain a conductive agent in order to impart antistatic properties, and preferred conductive agents include metal oxide particles or π-conjugated conductive polymers. An ionic liquid is also preferably used as the conductive compound.

  The fluorine-siloxane graft polymer refers to a copolymer polymer obtained by grafting polysiloxane containing siloxane and / or organosiloxane alone and / or organopolysiloxane to at least a fluorine-based resin. Examples of commercially available products include ZX-022H, ZX-007C, ZX-049, and ZX-047-D manufactured by Fuji Kasei Kogyo Co., Ltd.

  The silicone-based surfactant is a surfactant obtained by substituting a part of the methyl group of the silicone oil with a hydrophilic group. Examples of the hydrophilic group include polyether, polyglycerin, pyrrolidone, betaine, sulfate, phosphate, and quaternary salt. Specific products of silicone surfactants include, for example, SH200, BY16-873, PRX413 (dimethylsilicone oil; manufactured by Toray Dow Corning Silicone Co., Ltd.), SH203, SH230, SF8416 (alkyl-modified silicone oil; Toray Dow Corning Silicone Co., Ltd.), SF8417, BY16-208, BY16-209, BY16-849, BY16-872, FZ-2222, FZ-2207 (dimethylpolysiloxane / polyethylene oxide linear block copolymer; Japan) Unicar Co., Ltd. FZ series), KF-101, KF-102, KF-105 (epoxy-modified silicone oil; manufactured by Shin-Etsu Chemical Co., Ltd.), BYK-UV3500, BYK-UV3510, BYK-333, BYK- 31, BYK-337 (polyether-modified silicone oil, Bikkukemi - Japan Ltd.), but like without limitation.

  Moreover, it is preferable to add these components in 0.01-5 mass% with respect to the solid content component in a coating liquid.

(Surface shape of hard coat layer)
The hard coat layer surface according to the present invention preferably has an arithmetic average roughness Ra of 4 to 20 nm from the viewpoint of excellent anti-blocking effect when wound with a long film and adhesion with a cellulose acetate film.

  The arithmetic average roughness Ra is a value measured with an optical interference type surface roughness meter (RST / PLUS, manufactured by WYKO) based on the provisions of JIS B0601: 1994.

Moreover, as for uneven | corrugated average space | interval Sm, 3-40 micrometers is preferable. Further, the ratio (Ra / Sm) between the arithmetic average roughness Ra of the hard coat layer and the uneven average interval Sm of the hard coat layer-coated surface of the cellulose acetate film is 2 × 10 ^{−4 to} 6 × 10 ⁻³ . Preferably there is.

  Sm can be measured with an optical interference type surface roughness meter (RST / PLUS, manufactured by WYKO) based on the provisions of JIS B0601: 1994, similarly to the arithmetic average roughness Ra.

  In order to set the arithmetic average roughness Ra within the above range, a method of forming protrusions on the surface by pressing a mold, a method of forming surface irregularities by mixing resins having different SP values (solubility parameters), spinodal decomposition, A method of forming protrusions by nucleation or the like can be used.

  In addition, as the mold roll used for forming the protrusions, it is possible to appropriately select and apply a fine unevenness to a rough one, and a pattern, mat shape, lenticular lens shape, and spherical unevenness are regularly or randomly arranged. Can be used.

  Further, the haze value of the hard coat film of the present invention is preferably 1% or less from the viewpoint of clearness in that sufficient brightness and high contrast can be obtained.

<Functional layer>
In addition to the hard coat layer, the hard coat film of the present invention can be provided with functional layers such as a back coat layer, an antireflection layer, and an antiglare layer.

(Back coat layer)
The hard coat film according to the present invention may be provided with a back coat layer on the surface opposite to the side on which the hard coat layer of the cellulose acetate film is provided in order to prevent curling and blocking.

  In terms of curling and blocking prevention, the back coat layer includes silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, tin oxide, indium oxide, Particles such as zinc oxide, ITO, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate can be added.

  The particles contained in the backcoat layer are preferably 0.1 to 50% by mass with respect to the binder. When the back coat layer is provided, the increase in haze is preferably 0.5% or less, and particularly preferably 0.1% or less. As the binder, a cellulose ester resin is preferable. The coating composition for forming the backcoat layer preferably contains a solvent for alcohols, ketones and / or acetate ester sugars.

(Antireflection layer)
The hard coat film according to the present invention can be used as an antireflection film having an antireflection function for external light by coating an antireflection layer on the hard coat layer.

  The antireflection layer is preferably laminated in consideration of the refractive index, the film thickness, the number of layers, the layer order, and the like so that the reflectance is reduced by optical interference. The antireflection layer is composed of a low refractive index layer having a lower refractive index than the protective film as the support, or a combination of a high refractive index layer and a low refractive index layer having a higher refractive index than the protective film as the support. Preferably it is. Particularly preferably, it is an antireflection layer composed of three or more refractive index layers, and three layers having different refractive indexes from the support side are divided into medium refractive index layers (high refractive index layers having a higher refractive index than the support). Are preferably laminated in the order of a layer having a lower refractive index) / a high refractive index layer / a 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.

  As the layer structure of the antireflection film, the following structure is conceivable, but is not limited thereto.

Cellulose acetate film / hard coat layer / low refractive index layer Cellulose acetate film / hard coat layer / medium refractive index layer / low refractive index layer Cellulose acetate film / hard coat layer / medium refractive index layer / high refractive index layer / low refractive index Layer Cellulose acetate film / hard coat layer / high refractive index layer (conductive layer) / low refractive index layer Cellulose acetate film / hard coat layer / antiglare layer / low refractive index layer (low refractive index layer)
The low refractive index layer preferably contains silica-based fine particles, and the refractive index is preferably in the range of 1.30 to 1.45 when measured at 23 ° C. and a wavelength of 550 nm.

  The film thickness of the low refractive index layer is preferably 5 nm to 0.5 μm, more preferably 10 nm to 0.3 μm, and most preferably 30 nm to 0.2 μm.

  The composition for forming a low refractive index layer preferably contains at least one kind of particles having an outer shell layer and porous or hollow inside as silica-based fine particles. In particular, the particles having the outer shell layer and having a porous or hollow interior are preferably hollow silica-based fine particles.

  The composition for forming a low refractive index layer may contain an organosilicon compound represented by the following general formula (OSi-1), a hydrolyzate thereof, or a polycondensate thereof.

General formula (OSi-1): Si (OR) ₄
In the organic silicon compound represented by the general formula, R represents an alkyl group having 1 to 4 carbon atoms. Specifically, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane and the like are preferably used.

  In addition, a silane coupling agent, a curing agent, a surfactant and the like may be added as necessary. Moreover, you may contain the compound which has a thermosetting and / or photocurability which mainly contains the fluorine atom which contains a fluorine atom in 35-80 mass%, and contains a crosslinkable or polymeric functional group. Specifically, a fluorine-containing polymer or a fluorine-containing sol-gel compound is used. As the fluorine-containing polymer, for example, a hydrofluorinated monomer in addition to a hydrolyzate or dehydration condensate of a perfluoroalkyl group-containing silane compound [eg (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane] Examples thereof include fluorine-containing copolymers having units and cross-linking reactive units as constituent units. In addition, you may add a solvent, a silane coupling agent, a hardening | curing agent, surfactant, etc. as needed.

(High refractive index layer)
The refractive index of the high refractive index layer is preferably adjusted to a refractive index in the range of 1.4 to 2.2 by measuring at 23 ° C. and a wavelength of 550 nm. The thickness of the high refractive index layer is preferably 5 nm to 1 μm, more preferably 10 nm to 0.2 μm, and most preferably 30 nm to 0.1 μm. The means for adjusting the refractive index can be achieved by adding metal oxide fine particles and the like. Metal oxide The metal oxide fine particles used preferably have a refractive index of 1.80 to 2.60, more preferably 1.85 to 2.50.

  The kind of metal oxide fine particles is not particularly limited, and Ti, Zr, Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Al, Mg, Si, P and S A metal oxide having at least one element selected from the group consisting of Al, In, Sn, Sb, Nb, a halogen element, Ta and the like is doped with a minute amount of atoms. May be. A mixture of these may also be used. In the present invention, at least one metal oxide fine particle selected from zirconium oxide, antimony oxide, tin oxide, zinc oxide, indium tin oxide (ITO), antimony doped tin oxide (ATO), and zinc antimonate is used. It is particularly preferable to use it as the main component. In particular, it is preferable to contain zinc antimonate particles.

  The average particle diameter of the primary particles of these metal oxide fine particles is in the range of 10 nm to 200 nm, particularly preferably 10 to 150 nm. The average particle diameter of the metal oxide fine particles can be measured from an electron micrograph taken with a scanning electron microscope (SEM) or the like. You may measure by the particle size distribution meter etc. which utilize a dynamic light scattering method, a static light scattering method, etc. If the particle size is too small, aggregation tends to occur and the dispersibility deteriorates. If the particle size is too large, the haze is remarkably increased, which is not preferable. The shape of the metal oxide fine particles is preferably a rice grain shape, a spherical shape, a cubic shape, a spindle shape, a needle shape, or an indefinite shape.

  The metal oxide fine particles may be surface-treated with an organic compound. By modifying the surface of the metal oxide fine particles with an organic compound, the dispersion stability in an organic solvent is improved, the dispersion particle size can be easily controlled, and aggregation and sedimentation over time can be suppressed. . For this reason, the surface modification amount with a preferable organic compound is 0.1 mass%-5 mass% with respect to metal oxide particle, More preferably, it is 0.5 mass%-3 mass%. Examples of the organic compound used for the surface treatment include polyols, alkanolamines, stearic acid, silane coupling agents, and titanate coupling agents. Of these, silane coupling agents are preferred. Two or more kinds of surface treatments may be combined. The high refractive index layer may contain a π-conjugated conductive polymer. The π-conjugated conductive polymer can be used as long as it is an organic polymer having a main chain composed of a π-conjugated system. Examples thereof include polythiophenes, polypyrroles, polyanilines, polyphenylenes, polyacetylenes, polyphenylene vinylenes, polyacenes, polythiophene vinylenes, and copolymers thereof. From the viewpoint of ease of polymerization and stability, polythiophenes, polyanilines, and polyacetylenes are preferable.

  The π-conjugated conductive polymer can provide sufficient conductivity and solubility in a binder resin even if it is not substituted, but in order to further improve conductivity and solubility, an alkyl group, a carboxy group, a sulfo group, an alkoxy group. A functional group such as a group, a hydroxy group, or a cyano group may be introduced.

Moreover, you may contain an ionic compound. Examples of the ionic compound include imidazolium-based, pyridium-based, alicyclic amine-based, aliphatic amine-based, aliphatic phosphonium-based cations and inorganic ion-based compounds such as BF ₄ -and PF _6- , CF ₃ SO _2-, and the like. , (CF ₃ SO ₂ ) ₂ N—, and a compound comprising a fluorine-based anion such as CF ₃ CO ₂ —. The ratio of the polymer to the binder is preferably 10 to 400 parts by mass of the binder with respect to 100 parts by mass of the polymer, and particularly preferably 100 to 200 parts by mass of the binder with respect to 100 parts by mass of the polymer.

(Anti-glare layer)
The antiglare layer reduces the visibility of the reflected image by blurring the outline of the image reflected on the film surface, so that the reflected image is reflected when using an image display device such as a liquid crystal display, an organic EL display, or a plasma display. Specifically, it is a layer that does not bother the inclusion, and specifically, the arithmetic average of the surface of the layer by adding fine particles etc. to the hard coat layer and by forming a projection on the surface by pressing the mold A layer in which the roughness Ra is adjusted to 0.1 to 1 μm is preferable.

  Moreover, it is preferable that the ratio (scattering reflection ratio) of the scattering reflectance which occupies for the integral reflectance of the said glare-proof layer is 2 to 60%. By controlling the scattering reflection ratio within the above range using fine particles or the like, the interlayer adhesion between the cellulose acetate film having a high acetylation degree as described above and the antiglare layer can be improved. More preferably, if the ratio of the scattering reflection ratio is in the range of 20 to 50%, the adhesion can be improved.

  The scattering reflectance ratio is SCI (integrated reflectance) and SCE (scattering reflectance) using a spectrocolorimeter CM-2500d manufactured by Konica Minolta Co., Ltd. under the conditions of a measurement diameter of 8 mm and an observation field of view of 2 °. Can be determined by measuring.

<Polarizing plate>
A polarizing plate using the hard coat film of the present invention will be described. The polarizing plate can be produced by a general method.

  For example, a completely saponified polyvinyl alcohol aqueous solution is applied to at least one surface of a polarizing film prepared by subjecting the back side of the hard coat film of the present invention to an alkali saponification treatment and immersing and stretching the treated hard coat film in an iodine solution. It is preferable to use and bond together.

  The other surface may be the hard coat film or the cellulose acetate film described above. KC8UX2MW, KC4UX, KC5UX, KC4UY, KC8UY, KC12UR, KC4UEW, KC8UCR-3, KC8UCR-4, KC8UCR-5, KC4FR-1, KC4FR-2, KC8UE, KC4UE, KC4UE May be used. In other commercially available products, it is preferable to use Arton Film (manufactured by JSR Corporation) and Zeonore Film (manufactured by Nippon Zeon Corporation).

  The polarizing film, which is the main component of the polarizing plate, is an element that transmits only light having a polarization plane in a certain direction. A typical polarizing film known at present is a polyvinyl alcohol polarizing film, which is a polyvinyl alcohol film. There are those in which iodine is dyed on a system film and those in which dichroic dye is dyed, but it is not limited to this.

  As the polarizing film, a polyvinyl alcohol aqueous solution is formed and dyed by uniaxially stretching or dyed, or uniaxially stretched after dyeing, and then preferably subjected to a durability treatment with a boron compound. A polarizing film having a thickness of 5 to 30 μm, preferably 8 to 15 μm, is preferably used.

  On the surface of the polarizing film, one side of the hard coat film according to the present invention is bonded to form a polarizing plate. It is preferably bonded with an aqueous adhesive mainly composed of completely saponified polyvinyl alcohol or the like.

(Adhesive layer)
The pressure-sensitive adhesive layer used on one side of the film to be bonded to the substrate of the liquid crystal cell is preferably optically transparent and exhibits moderate viscoelasticity and adhesive properties.

  Specific examples of the adhesive layer include adhesives or adhesives such as acrylic copolymers, epoxy resins, polyurethane, silicone polymers, polyethers, butyral resins, polyamide resins, polyvinyl alcohol resins, and synthetic rubbers. A film such as a drying method, a chemical curing method, a thermal curing method, a thermal melting method, a photocuring method, or the like can be formed and cured using a polymer such as the above. Among them, the acrylic copolymer can be preferably used because it is most easy to control the physical properties of the adhesive and is excellent in transparency, weather resistance, durability and the like.

<Liquid crystal display device>
By incorporating the polarizing plate of the present invention produced using the hard coat film of the present invention into a display device, an image display device having various visibility and high durability can be produced.

  The hard coat film of the present invention is incorporated in a polarizing plate, and is a reflection type, transmission type, transflective liquid crystal display device or TN type, STN type, OCB type, HAN type, VA type (PVA type, MVA type), IPS type. It is preferably used in liquid crystal display devices of various driving systems such as OCB type.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not limited to these.

Example 1
<Production of Cellulose Acetate Film 101>
<Fine particle dispersion 1>
・ Silica fine particles (Aerosil R972V manufactured by Nippon Aerosil Co., Ltd.)
11 parts by mass / ethanol 89 parts by mass 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.
・ 99 parts by mass of methylene chloride ・ 5 parts by mass of fine particle dispersion 1 <Main dope solution>
A main dope solution having the following composition was prepared. First, methylene chloride and ethanol were added to the pressure dissolution tank. Next, cellulose acetate was added to the pressurized dissolution tank containing the solvent while stirring. This was completely dissolved with heating and stirring. This was designated as Azumi Filter Paper No. The main dope solution was prepared by filtration using 244.
-Methylene chloride 340 parts by mass-Ethanol 64 parts by mass-Acetylation degree 55% cellulose acetate (manufactured by Eastman Kodak Company)
100 parts by mass / ester compound 2-16 6.0 parts by mass / additive (described in Table 1) 6.0 parts by mass / particulate additive solution 1 1 part by mass A dope solution was prepared. Next, using an endless belt casting apparatus, the dope solution was uniformly cast on a stainless steel belt support at a temperature of 33 ° C. and a width of 1500 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 was 75%, and then peeled off from the stainless steel belt support with a peeling tension of 130 N / m.

  The peeled cellulose acetate film was stretched 36% 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. After drying, it was slit into a width of 1.5 m, a knurling process having a width of 10 mm and a height of 10 μm was applied to both ends of the film, and wound into a roll to obtain a cellulose acetate film 101 having a dry film thickness of 40 μm. The winding length was 5200 m.

<Production of Cellulose Acetate Films 102 to 104>
Cellulose acetate films 102 to 104 were produced in the same manner as the cellulose acetate film 101 except that the additives were changed as shown in Table 1.

<Production of Cellulose Acetate Film 105>
Cellulose acetate film 105 was produced in the same manner except that cellulose acetate having an acetylation degree of 55% was changed to cellulose acetate having an acetylation degree of 51%.

<Production of Cellulose Acetate Film 106>
A cellulose acetate film 106 was produced in the same manner except that the additive was changed to biphenyl diphenyl phosphate in the production of the cellulose acetate film 105.

[Preparation of Hard Coat Film 1]
On the cellulose acetate film 101 prepared above, the following hard coat layer composition 1 filtered through a polypropylene filter having a pore size of 0.4 μm was applied using an extrusion coater, dried at a temperature of 80 ° C., and then oxygenated. While purging with nitrogen so that the atmosphere has a concentration of 1.0% by volume or less, the illuminance of the irradiated part is 100 mW / cm ² using an ultraviolet lamp, the irradiation amount is 0.25 J / cm ² , and the coating layer is cured. A hard coat layer 1 having a dry film thickness of 3 μm was formed and wound to prepare a roll-shaped hard coat film 1.

<< Hard Coat Layer Composition 1 >>
The following materials were stirred and mixed to obtain hard coat layer coating composition 1.
・ Pentaerythritol tri / tetraacrylate 50 parts by mass (NK ester A-TMM-3L, manufactured by Shin-Nakamura Chemical Co., Ltd.)
-50 parts by mass of urethane acrylate (Beamset 575CB, manufactured by Arakawa Chemical Co., Ltd.)-2 parts by mass of Irgacure 184 (manufactured by BASF Japan)-Polyether-modified polydimethylsiloxane (BYK-UV3510, Big Chemie Japan, Inc.) 1) parts by mass, 10 parts by mass of cyclohexanone, 93 parts by mass of methyl ethyl ketone [Preparation of hard coat film 2]
In the production of the hard coat film 1, the hard coat film 2 was produced in the same manner except that the dry film thickness of the hard coat layer was changed to 5 μm.

[Preparation of Hard Coat Film 3]
In the production of the hard coat film 1, a hard coat film 3 was produced in the same manner except that the dry film thickness of the hard coat layer was changed to 10 μm.

[Preparation of Hard Coat Film 4]
In the production of the hard coat film 1, the hard coat film coating composition 1 was changed to the following hard coat layer coating composition 2, and the hard coat film was similarly changed except that the dry film thickness of the hard coat layer was changed to 10 μm. 4 was produced.

<< Hard Coat Layer Coating Composition 2 >>
The following materials were stirred and mixed to obtain hard coat layer coating composition 2.
・ Pentaerythritol tri / tetraacrylate 25 parts by mass (NK ester A-TMM-3L, manufactured by Shin-Nakamura Chemical Co., Ltd.)
・ 25 parts by mass of urethane acrylate (Beamset 575CB, manufactured by Arakawa Chemical Industries) ・ 2 parts by mass of Irgacure 184 (manufactured by BASF Japan) ・ Polyether-modified polydimethylsiloxane (BYK-UV3510, BYK Chemie Japan) 1) parts by mass / silica fine particle dispersion (silica concentration 35%, average particle size 20 nm, MEK-ST-MS sol manufactured by Nissan Chemical Industries) 143 parts by mass / cyclohexanone 10 parts by mass [Preparation of Hard Coat Film 5]
In the production of the hard coat film 4, the hard coat film 5 was produced in the same manner except that the dry film thickness of the hard coat layer was changed to 20 μm.

[Preparation of Hard Coat Film 6]
In the production of the hard coat film 4, the hard coat film 6 was produced in the same manner except that the dry film thickness of the hard coat layer was changed to 24 μm.

[Preparation of Hard Coat Film 7]
A hard coat film 7 was produced in the same manner except that the cellulose acetate film was changed from 101 to 102 in the production of the hard coat film 4.

[Preparation of Hard Coat Film 8]
A hard coat film 8 was prepared in the same manner except that the cellulose acetate film was changed from 101 to 103 in the production of the hard coat film 4.

[Preparation of Hard Coat Film 9]
A hard coat film 9 was produced in the same manner except that the cellulose acetate film was changed from 101 to 104 in the production of the hard coat film 4.

[Preparation of Hard Coat Film 10]
A hard coat film 10 was produced in the same manner except that the cellulose acetate film was changed from 101 to 105 in the production of the hard coat film 1.

[Preparation of Hard Coat Film 11]
A hard coat film 11 was produced in the same manner except that the cellulose acetate film was changed from 101 to 105 in the production of the hard coat film 4.

[Preparation of Hard Coat Film 12]
A hard coat film 12 was produced in the same manner except that the cellulose acetate film was changed from 101 to 105 in the production of the hard coat film 6.

[Preparation of Hard Coat Film 13]
A hard coat film 13 was produced in the same manner except that the cellulose acetate film was changed from 101 to 106 in the production of the hard coat film 4.

[Preparation of Hard Coat Film 14]
In the preparation of the hard coat film 2, the hard coat layer coating composition 1 was prepared with reference to Example 1 of JP-A-2009-263600, except that the hard coat layer coating composition 3 was changed to the following hard coat layer coating composition 3. A hard coat film 14 was produced.

<< Hard Coat Layer Composition 3 >>
The following materials were stirred and mixed to obtain hard coat layer coating composition 3.
-Urethane acrylate: 80 parts by mass of UA-306H (Kyoeisha Chemical)-Acrylic monomer: PE-3A (pentaerythritol triacrylate, Kyoeisha Chemical) 10 parts by mass-Initiator: Irgacure 184 (manufactured by BASF Japan) 1.5 parts by mass・ Fluorine-based additive: Optool DAC (Daikin Industries) 0.5 mass part ・ Solvent: Ethyl acetate 100 mass part << Evaluation >>
The produced hard coat films 1 to 14 were evaluated by the following tests. The obtained results are shown in Table 1.

  In addition, the hard coat films 2-5, 9 and 11 are hard coat films according to the present invention, and the hard coat films 1, 6-8, 10 and 12-14 are hard coat films for comparison.

<Weather resistance test>
Samples each 10 cm × 10 cm in size were cut out from the roll-shaped hard coat films 1 to 14 prepared above, and heat shock test (−40 ° C./30 minutes, then 85 ° C./30 minutes, assuming outdoor use) After alternating 550 cycles, light was irradiated for 168 hours with a light resistance tester (Isuper UV tester, manufactured by Iwasaki Electric Co., Ltd.).

a. Pencil hardness test About the hard coat films 1-14 after a weather resistance test, the hardness was confirmed by the pencil hardness test. Using the test pencil specified by JIS-S6006, according to the pencil hardness evaluation method specified by JIS-K5400, the hard coat layer surfaces of the hard coat films 1 to 14 are applied 5 times with a pencil of each hardness using a 500 g weight. Scratching was repeated, and the hardness of up to one scratch was measured.

b. Adhesion evaluation Each hard coat film 1-14 after the weather resistance test was conditioned in an atmosphere of 23 ° C. and 55% RH for 12 hours, and in accordance with JISK5400, 11 cuts were made vertically and horizontally at intervals of 1 mm. 100 square grids of 1 mm square were prepared, cellophane tape was applied and peeled off quickly at an angle of 90 degrees, and the number of grids remaining without peeling was counted. Evaluation was made according to the following criteria.

A: Not peeled at all ○: The peeled area ratio was less than 5% Δ: The peeled area ratio was less than 10% ×: The peeled area ratio was 10% or more The results obtained are shown in Table 1.

  As is clear from the results in Table 1, in a hard coat film having a hard coat layer on a cellulose acetate film having an acetylation degree of 51.0% to 56.0%, the cellulose acetate film contains a sugar ester compound, and If the pencil hardness of the hard coat film is 2H or more and 7H or less (measured value based on JIS K5400), it can be seen that the adhesion after the weather resistance test is excellent. In particular, it can be seen that the hard coat film of the present invention having a pencil hardness of 4H or more and 7H or less is particularly excellent in adhesion after a weather resistance test.

Example 2
<Production of cellulose acetate films 107-113>
Cellulose acetate films 107 to 113 were produced in the same manner as the cellulose acetate film 101 except that the additives were changed as shown in Table 2.

[Preparation of hard coat films 15 to 21]
In the production of the hard coat film 4, hard coat films 15 to 21 were produced in the same manner except that the cellulose acetate film 101 was changed to the cellulose acetate films 107 to 113, respectively.

<Evaluation>
About the produced hard coat films 15-21 and the hard coat film 4, pencil hardness and adhesiveness were evaluated like Example 1 except having changed the conditions of the weather resistance test into the following. The obtained results are shown in Table 2.

<Weather resistance test>
Samples of 10 cm × 10 cm size were cut out from each of the hard coat films 15 to 21 and hard coat film 4 produced above, and cycled for 750 cycles in a cycle thermo (40 ° C., 30 minutes left, then 85 ° C., 30 minutes left alternately) After the charging, the sample was irradiated with light for 240 hours using a light resistance tester (Isuper UV tester, manufactured by Iwasaki Electric Co., Ltd.).

  As can be seen from the results in Table 2, the cellulose acetate film contains a compound represented by the general formula (1) and having a total average substitution degree of 5.0 to 6.9, whereby a more severe light resistance test. In the mechanical test, it was revealed that excellent adhesion was exhibited.

Example 3
[Preparation of Hard Coat Film 22]
In the production of the hard coat film 4, a hard coat film 22 was produced in the same manner except that the hard coat layer coating composition 2 was changed to the following hard coat layer coating composition 4.

<< Hard Coat Layer Composition 4 >>
<Preparation of reactive silica particles (Xa)>
(Preparation of organic compound (X) having a polymerizable unsaturated group)
While stirring 60 parts by mass of isophorone diisocyanate in a solution consisting of 23 parts by mass of mercaptopropyltrimethoxysilane and 0.5 parts by mass of dibutyltin dilaurate, the mixture was added dropwise at 50 ° C. over 1 hour and then stirred at 70 ° C. for 3 hours. To this was added 202 parts by mass of NK ester A-TMM-3L made by Shin-Nakamura Chemical at 30 ° C. over 1 hour, and then the mixture was heated and stirred at 60 ° C. for 3 hours to obtain the specific organic compound (S1). In the infrared absorption spectrum of the product, the absorption peak at 2550 cm −1 characteristic for the mercapto group in the raw material and the absorption peak at 2260 cm −1 characteristic for the isocyanate group disappeared, and [−O—C (= A peak at 1660 cm −1 characteristic for the carbonyl and a peak at 1720 cm −1 characteristic for the acryloyl group in the O) —NH—] and [—S—C (═O) —NH—] groups are observed. And a specific organic compound having both an acryloyl group as a polymerizable unsaturated group, a [—S—C (═O) —NH—] group, and a [—O—C (═O) —NH—] group is formed. Showed that.

  9.36 parts by mass of the prepared composition (including 7.28 parts by mass of the organic compound (X) having a polymerizable unsaturated group), silica particle dispersion (silica concentration: 31%, Nissan Chemical MEK sol) After stirring a mixed solution of 07 parts by mass, 0.13 parts by mass of ion-exchanged water and 0.01 parts by mass of p-hydroxyphenyl monomethyl ether at 60 ° C. for 4 hours, 1.45 parts by mass of methyl orthoformate was added. Further, a dispersion of reactive silica particles (Xa) was obtained by stirring with heating at the same temperature for 1 hour. 2 g of this dispersion was weighed on an aluminum dish, dried on a hot plate at 175 ° C. for 1 hour, and weighed to determine the solid content, which was 35.7%. The average particle size of the silica particles was 40 nm. Here, the average particle diameter was measured with a transmission electron microscope.

And the following material was stirred and mixed and it was set as the hard-coat layer coating composition 4.
・ Pentaerythritol tri / tetraacrylate 25 parts by mass (NK ester A-TMM-3L, manufactured by Shin-Nakamura Chemical Co., Ltd.)
-25 parts by mass of urethane acrylate (Beamset 575CB, manufactured by Arakawa Chemical Co., Ltd.)-2 parts by mass of Irgacure 184 (manufactured by BASF Japan)-Polyether-modified polydimethylsiloxane (BYK-UV53510,
1 mass part / reactive silica particle dispersion (reactive silica particles (Xa) 35.7%)
140 parts by mass / cyclohexanone 10 parts by mass [Preparation of hard coat film 23]
On the cellulose acetate film 101, the following hard coat layer coating composition 5 is filtered through a polypropylene filter having a pore size of 0.4 μm to prepare a hard coat layer coating solution, which is applied using an extrusion coater, and dried at 80 ° C. Thereafter, using a UV lamp, the irradiance of the irradiated portion was 80 mW / cm ² and the irradiation amount was 50 mJ / cm ² to cure the coating layer to form a hard coat layer 1 having a dry film thickness of 1 μm. Continuously, the hard coat layer coating composition 4 is applied onto the hard coat layer 1 by an extrusion coater, dried at 80 ° C., and purged with nitrogen so that the atmosphere has an oxygen concentration of 1.0 vol% or less. While using an ultraviolet lamp, the illuminance of the irradiated part was 100 mW / cm ² , the irradiation amount was 0.25 J / cm ² , the coating layer was cured, and the hard coat layer 2 having a dry film thickness of 9 μm was formed and wound up. A hard coat film 23 was produced.

<< Hard Coat Layer Coating Composition 5 >>
The following materials were stirred and mixed to obtain hard coat layer coating composition 5.
・ Pentaerythritol tri / tetraacrylate 50 parts by mass (NK ester A-TMM-3L, manufactured by Shin-Nakamura Chemical Co., Ltd.)
・ 50 parts by mass of urethane acrylate (Beam Set 575CB, manufactured by Arakawa Chemical Co., Ltd.) ・ 3 parts by mass of UV absorber (TINUVIN 109)

・ Irgacure 184 (manufactured by BASF Japan) 2 parts by mass ・ Polyether-modified polydimethylsiloxane (BYK-UV3510, manufactured by BYK Japan KK) 1 part by mass ・ 10 parts by mass of cyclohexanone ・ 93 parts by mass of methyl ethyl ketone [hard coat Production of Film 24]
A hard coat film 24 was prepared in the same manner as in the preparation of the hard coat film 21 except that the hard coat layer coating composition 5 was changed to the hard coat layer coating composition 6.

<< Hard Coat Layer Coating Composition 6 >>
The following materials were stirred and mixed to obtain hard coat layer coating composition 6.
・ Pentaerythritol tri / tetraacrylate 50 parts by mass (NK ester A-TMM-3L, manufactured by Shin-Nakamura Chemical Co., Ltd.)
・ 50 parts by mass of urethane acrylate (Beam Set 575CB, manufactured by Arakawa Chemical Co., Ltd.) ・ 3 parts by mass of UV absorber (TINUVIN 405)

-Irgacure 184 (manufactured by BASF Japan) 2 parts by mass-Polyether-modified polydimethylsiloxane (BYK-UV3510, manufactured by Big Chemie Japan) 1 part by mass-10 parts by mass of cyclohexanone-93 parts by mass of methyl ethyl ketone << Evaluation >>
About the produced hard coat films 22-24 and the hard coat film 4, pencil hardness and adhesiveness were evaluated like Example 1 except having changed the conditions of the weather resistance test into the following. The obtained results are shown in Table 3.

<Weather resistance test>
Samples each having a size of 10 cm × 10 cm were cut out from the roll-shaped hard coat films 22 to 24 and the hard coat film 4 produced above, and a heat shock test (alternating between −40 ° C. for 30 minutes and then 85 ° C. for 30 minutes) After 1000 cycles, the sample was irradiated with light for 500 hours with a light resistance tester (eye super UV tester, Iwasaki Electric Co., Ltd.).

  As can be seen from the results in Table 3, the hard coat layer contains reactive silica fine particles, or the hard coat layer is composed of two or more layers, and the hard coat layer in contact with the base film contains an ultraviolet absorber. The hard coat film of the invention is preferable because it has excellent adhesion even in a more severe light resistance tester test.

Example 4
Polarizing plate preparation:
<Preparation of norbornene polymer film>
First, a norbornene polymer was synthesized by the following method to prepare a norbornene polymer film.

(Synthesis of norbornene polymer 1)
NBOAc: 5-norbornen-2-yl acetate (bicyclo [2.2.1] hept-5-en-2-yl acetate)
Norbornene (NB): norbornylene or bicyclo [2.2.1] hept-5-ene) was purchased from Aldrich.

  150 parts by mass of toluene and 152 parts by mass of NBOAc were placed in a reaction vessel. Next, 0.018 parts by mass of allyl palladium chloride dimer (manufactured by Tokyo Chemical Industry Co., Ltd.) dissolved in 10 parts by mass of toluene, 0.028 parts by mass of tricyclohexylphosphine (manufactured by Strem Co.), and dimethylaniline dissolved in 5 parts by mass of methylene chloride. A reaction vessel was charged with 0.12 parts by mass of nium tetrakispentafluorophenylborate (manufactured by Strem) and 0.33 parts by mass of allyltributyltin (manufactured by Aldrich) dissolved in 10 parts by mass of toluene. When heating was started and the temperature reached 90 ° C., 130 parts by mass of NB dissolved in 20 parts by mass of toluene was added dropwise over 1 hour. The mixture was reacted at 90-100 ° C. for 6 hours. During this time, toluene was added as appropriate with an increase in the viscosity of the reaction solution. 10 parts by mass of 1-hexene (manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise, and further reacted for 1 hour. The obtained reaction solution was put into excess methanol to precipitate a polymer. The precipitate was collected, washed with methanol, and vacuum dried at 110 ° C. for 6 hours. The obtained polymer (norbornene polymer 1) was dissolved in tetrahydrofuran, and the molecular weight was measured by gel permeation chromatography. When the mass average molecular weight (Mw) was measured, the number average molecular weight (Mn) was 100200, the mass average molecular weight (Mw) was 256300, and the molecular weight distribution (Mw / Mn) was 2.56.

(Preparation of dope solution NB)
The following materials were sequentially put into a sealed container, the temperature in the container was raised from 20 ° C. to 80 ° C., and the mixture was stirred for 3 hours while maintaining the temperature at 80 ° C. to completely remove the norbornene polymer 1 Dissolved in. The silicon oxide fine particles were added dispersed in a solution of a solvent to be added in advance and a small amount of cellulose ester. This dope was filtered using filter paper (Azumi filter paper No. 244, manufactured by Azumi Filter Paper Co., Ltd.) to obtain a dope solution D.

(Dope solution NB)
-Norbornene polymer 1 100 parts by mass-Silicon oxide fine particles 0.1 part by mass (Aerosil R972V, manufactured by Nippon Aerosil Co., Ltd.)
-Methylene chloride 400 parts by mass-Ethanol 40 parts by mass-Butanol 5 parts by mass The above materials are mixed to prepare a dope solution D, and the resulting dope solution D is kept at a temperature of 35 ° C from a casting die. A web was formed by casting on a support made of an endless belt made at a temperature of 35 ° C. Next, the web was dried on the support, and the web was peeled from the support with a peeling roll when the residual solvent amount of the web reached 100% by mass.

  Next, the web is transported while being dried with a drying air of 110 ° C. in a drying process of transport by a plurality of rolls arranged on the top and bottom, and subsequently grips both ends of the web with a tenter, and then in the width direction (TD) at 150 ° C. It extended | stretched so that it might become 1.4 times before extending | stretching. After stretching with a tenter, the web was dried with a drying air of 155 ° C. in a transport drying process using a plurality of rolls arranged vertically. After drying, a knurling process having a width of 10 mm and an average height of 10 μm was applied to both ends, and wound up to prepare a norbornene polymer film (NB) having a width of 1.5 m, a film thickness of 80 μm, and a length of 3900 m. The retardation of the norbornene polymer film was Ro = 73 nm and Rt = 224 nm. The retardation is a value measured at a wavelength of 590 nm using an automatic birefringence meter KOBRA-21ADH (Oji Scientific Instruments) after humidity adjustment to 23 ° C. and 55% RH.

<Preparation of Polarizing Plate 201>
(Alkaline saponification treatment)
Next, the polarizing plate 201 was produced using the hard coat film 1 and the norbornene polymer film obtained above.

(A) Production of Polarizing Film What was impregnated with 10 parts by mass of glycerin and 170 parts by mass of water in 100 parts by mass of polyvinyl alcohol (hereinafter abbreviated as PVA) having a saponification degree of 99.95 mol% and a polymerization degree of 2400. After melt-kneading and defoaming, it was melt-extruded from a T-die onto a metal roll to form a film. Thereafter, the PVA film obtained by drying had an average thickness of 25 μm, a moisture content of 4.4%, and a film width of 3 m.

  Next, the obtained PVA film was continuously processed in the order of preliminary swelling, dyeing, uniaxial stretching by a wet method, fixing treatment, drying, and heat treatment to prepare a polarizing film. That is, the PVA film was preliminarily swollen in water at a temperature of 30 ° C. for 30 seconds, and immersed in an aqueous solution having an iodine concentration of 0.4 g / liter and a potassium iodide concentration of 40 g / liter at a temperature of 35 ° C. for 3 minutes. Subsequently, the film was uniaxially stretched 6 times in a 50% aqueous solution with a boric acid concentration of 4% under the condition that the tension applied to the film was 700 N / m, and the potassium iodide concentration was 40 g / liter and the boric acid concentration was 40 g / liter. Then, it was immersed in an aqueous solution having a zinc chloride concentration of 10 g / liter and a temperature of 30 ° C. for 5 minutes for fixing. Thereafter, the PVA film was taken out, dried with hot air at a temperature of 40 ° C., and further heat-treated at a temperature of 100 ° C. for 5 minutes. The obtained polarizing film had an average thickness of 13 μm, a polarizing performance of a transmittance of 43.0%, a polarization degree of 99.5%, and a dichroic ratio of 40.1.

(B) Production of Polarizing Plate A polarizing plate 101 was produced by bonding the polarizing film, the hard coat film 1 and the norbornene polymer film according to the following steps 1 to 4.

  Process 1: The above-mentioned polarizing film was immersed for 1 to 2 seconds in the storage tank of the polyvinyl alcohol adhesive agent solution of 2 mass% of solid content.

  Step 2: Alkali saponification treatment was performed on the hard coat film 1 obtained by attaching a peelable protective film (PET) to the norbornene polymer film and the hard coat layer under the following conditions. Next, excess adhesive adhered to the polarizing film immersed in the polyvinyl alcohol adhesive solution in Step 1 is gently removed, and the norbornene polymer film and the hard coat film 1 are sandwiched between the polarizing films as shown in FIG. And laminated.

(Alkaline saponification treatment)
Saponification step 2.5M-KOH 60 ° C. 120 seconds Water washing step Water 30 ° C. 60 seconds Neutralization step 10 parts HCl 30 ° C. 45 seconds Water washing step Water 30 ° C. 60 seconds After saponification treatment, water washing, neutralization, water washing in this order And then dried at 100 ° C.

Step 3: The laminate was bonded at a speed of about 2 m / min at a pressure of ^{20 to} 30 N / cm ² with two rotating rollers. At this time, it was carried out with care to prevent bubbles from entering.

  Step 4: The sample prepared in Step 3 was dried in a dryer at a temperature of 100 ° C. for 5 minutes to prepare a polarizing plate.

  Step 5: Apply a commercially available acrylic pressure-sensitive adhesive to the norbornene polymer film of the polarizing plate prepared in Step 4 so that the thickness after drying is 25 μm, and dry in an oven at 110 ° C. for 5 minutes to form an adhesive layer. Then, a peelable protective film was attached to the adhesive layer to produce a polarizing plate 201.

<Preparation of polarizing plates 202 to 214>
Polarizers 202 to 214 were produced in the same manner except that the hard coat film 1 was changed to the hard coat films 2 to 14 in the production of the polarizer 201.

<Production of Liquid Crystal Display Device 301>
Of two pairs of polarizing plates installed with a liquid crystal layer sandwiched in a 40-inch liquid crystal display device (manufactured by Sharp Corporation) using a VA type liquid crystal cell, the polarizing plate on one side on the viewer side is peeled off, and the above The produced polarizing plate 201 was bonded to the liquid crystal cell glass so that the hard coat layer was on the viewing side. The liquid crystal display device 301 was manufactured by arranging the transmission axis of the polarizing plate on the observer side and the transmission axis of the polarizing plate on the backlight side to be orthogonal to each other.

<Production of Liquid Crystal Display Devices 302 to 314>
Liquid crystal display devices 302 to 314 were similarly manufactured except that the polarizing plate 201 was changed to the polarizing plates 202 to 214 in the preparation of the liquid crystal display device 301. Next, the following evaluation was performed about the produced liquid crystal display devices 301 to 314.

<Evaluation>
a. Evaluation of Unevenness Each of the liquid crystal display devices produced above was allowed to stand for 100 hours at 60 ° C. and 90% RH, and then returned to 23 ° C. and 55% RH. Next, the visibility was evaluated according to the following criteria.

A: Unevenness is not recognized at all O: Slight unevenness is observed Δ: Fine unevenness is observed X: Unevenness is recognized

b. Visibility evaluation Each liquid crystal display device manufactured above is placed on a desk 80 cm high from the floor, and a daylight direct fluorescent lamp (FLR40S • D / MX Matsushita is placed on the ceiling 3 m high from the floor. 10 sets are arranged at intervals of 1.5 m with 40W × 2 as one set. In this case, when the evaluator is in front of the display surface of the liquid crystal display panel, the fluorescent lamp is arranged so that the fluorescent lamp comes to the back from above the evaluator's head, and the flatness is evaluated according to the following criteria.

◎: Fluorescent lamp looks straight ○: Fluorescent lamp appears to be bent slightly △: Fluorescent lamp appears to be bent ×: Fluorescent lamp appears to be greatly bent

  The above evaluation results are shown in Table 4.

  As can be seen from the results shown in Table 4, the liquid crystal display device using the polarizing plate of the present invention was excellent in unevenness and visibility, and when it was viewed for a long time, there was no eye fatigue or the like, which was very excellent. .

Claims (11)

A hard coat film having a hard coat layer on a cellulose acetate film having an acetylation degree of 51.0% to 56.0%, wherein the cellulose acetate film contains a sugar ester compound, and the pencil hardness of the hard coat film is 2H. Above, the hard coat film which is below 7H. The hard coat film according to claim 1, wherein the pencil hardness is 4H or more and 7H or less. The hard coat film according to claim 1, wherein the sugar ester compound is represented by the following general formula (1).

(In the formula, R _{1 to} R ₈ represent a substituted or unsubstituted alkylcarbonyl group having 2 to 22 carbon atoms or a substituted or unsubstituted arylcarbonyl group having 2 to 22 carbon atoms, and R _{1 to} R _8. May be the same or different.) The hard coat film according to any one of claims 1 to 3, wherein the total average substitution degree of the compound represented by the general formula (1) is 5.0 to 6.9. The hard coat according to any one of claims 1 to 4, wherein the hard coat layer contains reactive silica fine particles (Xa) surface-treated with an organic compound having a polymerizable unsaturated group. the film. The arithmetic average roughness Ra of the hard coat layer is 4 to 20 nm, and the ratio between the arithmetic average roughness Ra of the hard coat layer and the uneven average interval Sm of the hard coat layer-coated surface of the cellulose acetate film (Ra / Sm) is 2 * 10 < ^-4 > -6 * 10 < ^-3 >, The hard coat film of any one of Claims 1-5 characterized by the above-mentioned. The hard coat layer is an anti-glare layer, and the ratio of the scattering reflectance to the integrated reflectance of the anti-glare layer is 2 to 60%. Hard coat film as described in 2. The hard coat film according to claim 7, wherein a ratio of the scattering reflectance is 20 to 50%. The hard coat film according to any one of claims 1 to 8, wherein the hard coat layer is composed of two or more layers, and the hard coat layer in contact with the base film contains an ultraviolet absorber. . A polarizing plate comprising the hard coat film according to claim 1 on one surface. A liquid crystal display device using the hard coat film according to claim 1 or the polarizing plate according to claim 10.