KR20190137805A - Optical laminated body, polarizing plate, and image display device - Google Patents

Abstract

The optical laminated body by which the function of the surface treatment layer was fully provided is provided. The optical laminated body of this invention contains a base film and the surface treatment layer formed in the one side of a base film, a base film contains acrylic resin and core-shell particles disperse | distributed to acrylic resin, and the elasticity modulus of a base film is 4.0 GPa As mentioned above, the ratio of the component of the acrylic resin eluted to the surface treatment layer among the components which comprise a depth position of 3.0 micrometers in the direction of a surface treatment layer from the base film side is less than 20%.

Description

Optical laminated body, polarizing plate, and image display device

The present invention relates to an optical laminate, a polarizing plate, and an image display device.

In recent years, the optical laminated body which provided functional layers (surface treatment layer), such as a hard-coat layer, an anti-glare layer, an antireflection layer, on one side of the base film which consists of acrylic resin is known (patent document 1). Such an optical laminate can be used, for example, as a protective film of a polarizer or as a front plate of an image display device.

Japanese Patent Laid-Open No. 2016-218478

However, the above conventional optical laminated body may not fully provide the function of a surface treatment layer.

This invention is made | formed in order to solve the said conventional subject, The main objective is the optical laminated body with which the function of the surface treatment layer was fully provided, the polarizing plate provided with such an optical laminated body, and the image display apparatus provided with such a polarizing plate. It is to offer.

The optical laminated body of this invention contains a base film and the surface treatment layer formed in the one side of the said base film, The said base film contains acrylic resin and core-shell particles disperse | distributed to the said acrylic resin, An elasticity modulus is 4.0 GPa or more, and the ratio of the component of the said acrylic resin eluted to the said surface treatment layer among the components which comprise a depth position of 3.0 micrometers in the direction of the said surface treatment layer is less than 20%.

In one embodiment, when the refractive index of the said base film is called R1, and the refractive index in the depth position of 3.0 micrometers from the said base film side in the direction of the said surface treatment layer is called R3, it is R3> 0.2R1 + 0.8R2 (Where R1 < R2).

In one embodiment, the thickness of the said surface treatment layer is 3 micrometers-20 micrometers.

In one embodiment, the said base film contains 5 weight part-20 weight part of the said core-shell particles with respect to 100 weight part of said acrylic resins.

In one embodiment, the said acrylic resin has at least 1 chosen from the group which consists of a glutarimide unit, a lactone ring unit, a maleic anhydride unit, a maleimide unit, and a glutaric anhydride unit.

In one embodiment, the said surface treatment layer is a hardened layer of resin apply | coated on the said base film.

In one embodiment, the said surface treatment layer is at least 1 chosen from the group which consists of a hard-coat layer, an anti-glare layer, and an antireflection layer.

According to another situation of this invention, a polarizing plate is provided. This polarizing plate contains a polarizer and the protective layer arrange | positioned at the one side of the said polarizer, and the said protective layer is the said optical laminated body.

According to another aspect of the present invention, an image display apparatus is provided. This image display apparatus is provided with the said polarizing plate.

(Effects of the Invention)

According to this invention, the elasticity modulus of a base film is 4.0 GPa or more, and the component of the acrylic resin eluted to the surface treatment layer among components which comprise a depth position of 3.0 micrometers in the direction of a surface treatment layer is less than 20%. Thus, the optical laminated body to which the function of a surface treatment layer is fully provided, the polarizing plate provided with such an optical laminated body, and the image display apparatus provided with such a polarizing plate can be provided.

1 is a schematic cross-sectional view of an optical laminate according to one embodiment of the present invention.

 EMBODIMENT OF THE INVENTION Hereinafter, although embodiment of this invention is described, this invention is not limited to these embodiment.

A. Overall construction of the optical laminate

1 is a schematic cross-sectional view of an optical laminate according to one embodiment of the present invention. The optical laminated body 100 contains the base film 10 and the surface treatment layer 20 formed in the one side of the base film 10. The base film 10 contains an acrylic resin and core-shell particles dispersed in the acrylic resin. The elasticity modulus of the base film 10 is 4.0 GPa or more. The ratio of the component of the acrylic resin eluted to the surface treatment layer among the components which comprise a 3.0 micrometers depth position from the base film side in the direction of a surface treatment layer is less than 20%. The depth position of 3.0 micrometers in the direction of a surface treatment layer from the base film side is a position typically 3.0 micrometers apart in the direction of the surface treatment layer side from the interface of the surface treatment layer of a base film. The ratio of the component of acrylic resin of the said "3 micrometer depth position" is typically derived by the following method.

Calculation position (position from the surface treatment side) = surface treatment layer thickness (PET base material hard coat thickness)-(3 micrometers) of acrylic resin component

For example, when (PET base material hard coat thickness) is 15 micrometers, the ratio of the acrylic resin component of a 12 micrometer position is measured from the surface treatment side. The surface treatment layer thickness (hard coat thickness) is typically derived in the following order. First, using a PET substrate (Toray Industries, Inc., trade name: U48-3, refractive index: 1.60) as the base film, by drying the heating temperature of the coating layer at 70 ℃ and UV curing, the hard coat layer This formed optical laminated body is obtained. The black acrylic plate (Mitsubishi Rayon Co., Ltd. make, thickness 2mm) was stuck to the base material layer side of the obtained optical laminated body through the acrylic adhesive of thickness 20micrometer. Next, the reflection spectrum of a hard coat layer is measured on condition of the following using an instantaneous multi-metering system (made by Otsuka Electronics Co., Ltd., brand name: MCPD3700). Since the composition for hard-coat layer formation does not penetrate into the PET base material used for these laminated bodies, the thickness of only a hard-coat layer is measured from the peak position of the FFT spectrum obtained from a laminated body.

Reflective spectrum measurement conditions

Reference: Mirror

Algorithm: FFT Method

Calculation Wavelength: 450nm to 850nm

Detection condition

Exposure time: 20ms

Lamp Gain: Normal

Number of integrations: 10

FFT method

Range of film thickness values: 2 ~ 15㎛

Film thickness resolution: 24 nm

When the said ratio is 20% or more, the function (surface resistance typically, when a surface treatment layer is a hard-coat layer typically) of a surface treatment layer may not be fully provided, and also the adhesiveness of a base film and a surface treatment layer falls. There is a case. The ratio of the component of the acrylic resin eluted to the surface treatment layer among the components constituting a depth position of 3.0 μm in the direction of the surface treatment layer 20 from the base film 10 side can be measured by, for example, the prism coupler method. Can be. Specifically, the refractive index of the base film is referred to as R1, the refractive index of the surface treatment layer is referred to as R2, and the refractive index at the depth position of 3.0 µm in the direction of the surface treatment layer from the substrate film side measured by the prism coupler method. When it is called R3, the ratio X (%) of the component of the acrylic resin eluted to the surface treatment layer among the components which comprise a 3.0 micrometers depth position from the base film side in the direction of a surface treatment layer is represented by the following formula | equation.

X (%) = (R3-R2) × 100 / (R1-R2)

Therefore, as for the optical laminated body 100, regarding refractive index R1 of a base film, the refractive index R2 of a surface treatment layer, and the refractive index R3 in the depth position of 3.0 micrometers in the direction of a surface treatment layer from the base film side, Preferably it is the following. Satisfies the inequality of

R3> 0.2R1 + 0.8R2 (R1 <R2)

The thickness of the surface treatment layer is preferably 3 µm to 20 µm, and more preferably 5 µm to 15 µm. The base film 10 preferably contains 5 parts by weight to 20 parts by weight of the core-shell particles with respect to 100 parts by weight of the acrylic resin. The acrylic resin preferably has at least one selected from the group consisting of glutarimide units, lactone ring units, maleic anhydride units, maleimide units, and glutaric anhydride units. The surface treatment layer 20 is typically the cured layer of the resin composition applied on the base film 10. The surface treatment layer 20 is preferably at least one selected from the group consisting of a hard coat layer, an antiglare layer, and an antireflection layer. According to the said optical laminated body 100, the amount of elution to the surface treatment layer 20 of acrylic resin contained in the base film 10 is sufficiently small. Thereby, the fall of the functionality of the surface treatment layer by eluting acrylic resin to the surface treatment layer 20 can be suppressed. Specifically, when the surface treatment layer is a hard coat layer, a decrease in scratch resistance of the hard coat layer can be suppressed, and when the surface treatment layer is an antiglare layer, a decrease in the antiglare property of the antiglare layer can be suppressed, When the surface treatment layer is an antireflection layer, the antireflection of the antireflection layer can be suppressed. In addition, the adhesion between the base film 10 and the surface treatment layer 20 may be improved.

B. Base Film

B-1. Characteristics of the base film

As mentioned above, the base film contains an acrylic resin and core-shell particles dispersed in the acrylic resin. The thickness of a base film becomes like this. Preferably it is 5 micrometers-150 micrometers, More preferably, it is 10 micrometers-100 micrometers. The elasticity modulus of a base film is 4.0 kPa or more as mentioned above. When the base film forms the surface treatment layer mentioned later, an acrylic resin can elute to a surface treatment layer. The ratio of the component of acrylic resin in the component which comprises a depth position of 3.0 micrometers in the direction of a surface treatment layer from the base film side is less than 20%.

The base film is preferably substantially optically isotropic. In this specification, "it has substantially optically isotropy" means that in-plane phase difference Re (550) is 0 nm-10 nm, and phase difference Rth (550) of thickness direction is -10 nm-+10 nm. In-plane phase difference Re (550), More preferably, it is 0 nm-5 nm, More preferably, it is 0 nm-3 nm, Especially preferably, it is 0 nm-2 nm. The phase difference Rth 550 in the thickness direction is more preferably -5 nm to +5 nm, still more preferably -3 nm to +3 nm, and particularly preferably -2 nm to +2 nm. When Re (550) and Rth (550) of a base film are these ranges, the bad influence on a display characteristic can be prevented when an optical laminated body is applied to an image display apparatus. In addition, Re (550) is an in-plane phase difference of the film measured with the light of wavelength 550nm in 23 degreeC. Re (550) is obtained by the formula: Re (550) = (nx-ny) × d. Rth (550) is a phase difference of the thickness direction of the film measured with the light of wavelength 550nm in 23 degreeC. Rth (550) is obtained by the formula: Rth (550) = (nx-nz) x d. Where nx is the refractive index of the direction in which the in-plane refractive index is maximum (that is, the slow axis direction), ny is the refractive index of the direction orthogonal to the slow axis in the plane (ie, the fast axis direction), and nz is the thickness direction Refractive index, and d is the thickness of the film in nm.

It is more preferable that the light transmittance at 380 nm in 40 micrometers in thickness of a base film is high. Specifically, the light transmittance is preferably 85% or more, more preferably 88% or more, even more preferably 90% or more. If light transmittance is this range, desired transparency can be ensured. Light transmittance can be measured, for example by the method according to ASTM-D-1003.

The lower the haze of the base film, the lower the better. Specifically, the haze is preferably 5% or less, more preferably 3% or less, still more preferably 1.5% or less, particularly preferably 1% or less. If haze is 5% or less, a favorable clear feeling can be given to a film. Further, even when the optical laminate is used as a protective layer of the viewing side polarizing plate of the image display device, the display content can be visually recognized well.

YI in 40 micrometers in thickness of a base film becomes like this. Preferably it is 1.27 or less, More preferably, it is 1.25 or less, More preferably, it is 1.23 or less, Especially preferably, it is 1.20 or less. When YI exceeds 1.3, optical transparency may become inadequate. In addition, YI can be calculated | required by the following formula from the tristimulus value (X, Y, Z) of the color obtained by the measurement using the high-speed integrated sphere spectrophotometer (brand name DOT-3C: MURAKAMI COLOR RESEARCH LABORATORY), for example. .

YI = [(1.28X-1.06Z) / Y] × 100

The b value (measurement of the color according to the color system of Hunter) in the thickness of the substrate film is preferably less than 1.5, and more preferably 1.0 or less. When b value is 1.5 or more, unwanted color taste may come out. In addition, b value cut | disconnects a base film sample to 3 cm x 3 cm, for example, measures a color using a high-speed integrated sphere spectrophotometer (brand name DOT-3C: MURAKAMI COLOR RESEARCH LABORATORY), and measures the color Can be obtained by evaluation based on Hunter's color system.

The water vapor transmission rate of the base film is preferably 300 g / m 2 · 24 hr or less, more preferably 250 g / m 2 · 24 hr or less, more preferably 200 g / m 2 · 24 hr or less, particularly preferably 150 g / m 2 · 24 hr or less, most preferably Preferably it is 100 g / m <2> * 24hr or less. When the water vapor transmission rate of a base film is such a range, when using it as a protective layer of a polarizer, a polarizing plate excellent in durability and moisture resistance can be obtained.

The tensile strength of the base film is preferably 10 MPa or more and less than 100 MPa, more preferably 30 MPa or more and less than 100 MPa. In the case of less than 10 MPa, sufficient mechanical strength may not be expressed. When it exceeds 100 MPa, there is a fear that workability is insufficient. Tensile strength can be measured according to ASTM-D-882-61T, for example.

Tensile elongation of a base film becomes like this. Preferably it is 1.0% or more, More preferably, it is 3.0% or more, More preferably, it is 5.0% or more. The upper limit of tensile elongation is 100%, for example. If the tensile elongation is less than 1%, the toughness may be insufficient. Tensile elongation can be measured according to ASTM-D-882-61T, for example.

The tensile elasticity modulus of a base film is 4 GPa or more, Preferably it is 4.5 GPa or more. The upper limit of the tensile elasticity modulus is 20 GPa, for example. Tensile modulus can be measured according to ASTM-D-882-61T, for example.

The base film may contain arbitrary appropriate additives according to the objective. Specific examples of the additives include ultraviolet absorbers; Antioxidants such as hindered phenol, phosphorus and sulfur; Stabilizers such as light stabilizers, weather stabilizers, and heat stabilizers; Reinforcing materials such as glass fibers and carbon fibers; Near infrared absorbers; Flame retardants such as tris (dibromopropyl) phosphate, triallyl phosphate, and antimony oxide; Antistatic agents such as anionic, cationic and nonionic surfactants; Coloring agents such as inorganic pigments, organic pigments, and dyes; Organic fillers or inorganic fillers; Resin modifiers; Organic fillers and inorganic fillers; Plasticizers; slush; Etc. can be mentioned. An additive may be added at the time of superposition | polymerization of acrylic resin, and may be added at the time of film formation. The kind, number, combination, addition amount, etc. of the additive may be appropriately set according to the purpose.

B-2. Acrylic resin

B-2-1. Composition of Acrylic Resin

Arbitrary suitable acrylic resin can be employ | adopted as acrylic resin. Acrylic resin typically contains an alkyl (meth) acrylate as a main component as a monomer unit. In this specification, "(meth) acryl" means an acryl and / or methacryl. As an alkyl (meth) acrylate which comprises the main skeleton of acrylic resin, the C1-C18 thing of a linear or branched alkyl group can be illustrated. These may be used alone or in combination. Moreover, you may introduce arbitrary appropriate copolymerization monomers into copolymerization by acrylic resin. The kind, number, copolymerization ratio, etc. of such a copolymerization monomer may be appropriately set according to the purpose. The structural component (monomer unit) of the main skeleton of acrylic resin is mentioned later, referring General formula (2).

The acrylic resin preferably has at least one selected from glutarimide units, lactone ring units, maleic anhydride units, maleimide units, and glutaric anhydride units. Acrylic resin which has a lactone ring unit is described, for example in Unexamined-Japanese-Patent No. 2008-181078, The description of the said publication is integrated in this specification as a reference. The glutarimide unit is preferably represented by the following general formula (1):

In general formula (1), R <^1> and R <^2> represents a hydrogen atom or a C1-C8 alkyl group each independently, R <^3> represents a hydrogen atom, a C1-C18 alkyl group, a C3-C12 cycloalkyl group, Or an aryl group having 6 to 10 carbon atoms. In General formula (1), Preferably, R <^1> and R <^2> are respectively independently a hydrogen atom or a methyl group, and R <^3> is a hydrogen atom, a methyl group, a butyl group, or a cyclohexyl group. More preferably, R ¹ is a methyl group, R ² is a hydrogen atom, and R ³ is a methyl group.

The alkyl (meth) acrylate is typically represented by the following general formula (2):

In general formula (2), R <^4> represents a hydrogen atom or a methyl group, R <^5> represents a hydrogen atom or the C1-C6 aliphatic or alicyclic hydrocarbon group which may be substituted. As a substituent, a halogen and a hydroxyl group are mentioned, for example. Specific examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, and (meth) acrylate -Hexyl, cyclohexyl (meth) acrylate, chloromethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, (meth) acrylic acid 2,3,4,5,6-pentahydroxyhexyl and (meth) acrylic acid 2,3,4,5-tetrahydroxypentyl are mentioned. In General Formula (2), R ⁵ is preferably a hydrogen atom or a methyl group. Thus, particularly preferred alkyl (meth) acrylates are methyl acrylate or methyl methacrylate.

The said acryl-type resin may contain only the single glutarimide unit, and R <^1> , R <^2> and R <^{3> in the} said General formula (1) may contain the some glutarimide unit from another.

The content rate of the glutarimide unit in the said acrylic resin becomes like this. Preferably it is 2 mol%-50 mol%, More preferably, 2 mol%-45 mol%, More preferably, 2 mol%-40 mol%, Especially preferably, 2 mol% 35 mol%, most preferably 3 mol%-30 mol%. When the content ratio is less than 2 mol%, there is a fear that the effects (for example, high optical properties, high mechanical strength, excellent adhesion to the polarizer, and thinning) derived from the glutarimide unit may not be sufficiently exhibited. If the content ratio exceeds 50 mol%, there is a fear that heat resistance and transparency are insufficient, for example.

The said acrylic resin may contain only a single alkyl (meth) acrylate unit, and R <^4> and R <^5> in the said General formula (2) may contain the some some alkyl (meth) acrylate unit different.

The content rate of the alkyl (meth) acrylate unit in the said acrylic resin becomes like this. Preferably it is 50 mol%-98 mol%, More preferably, 55 mol%-98 mol%, More preferably, 60 mol%-98 mol%, Especially preferably, Is 65 mol% to 98 mol%, most preferably 70 mol% to 97 mol%. When the content ratio is less than 50 mol%, there is a fear that the effect (for example, high heat resistance and high transparency) derived from the alkyl (meth) acrylate unit is not sufficiently exhibited. When the said content rate is more than 98 mol%, resin will fall back and it will be easy to be damaged, high mechanical strength cannot fully be exhibited and there exists a possibility that productivity may be inferior.

The said acrylic resin may contain units other than a glutarimide unit and an alkyl (meth) acrylate unit.

In one embodiment, acrylic resin can contain 0-10 weight% of unsaturated carboxylic acid units which do not participate in the intramolecular imidation reaction mentioned later, for example. The content rate of an unsaturated carboxylic acid unit becomes like this. Preferably it is 0 to 5 weight%, More preferably, it is 0 to 1 weight%. If content is such a range, transparency, retention stability, and moisture resistance can be maintained.

In one embodiment, acrylic resin can contain the copolymerizable vinylic monomer unit (other vinylic monomeric unit) of that excepting the above. As other vinylic monomers, for example, acrylonitrile, methacrylonitrile, ethacrylonitrile, allyl glycidyl ether, maleic anhydride, itaconic anhydride, N-methylmaleimide, N-ethylmaleimide, N Cyclohexylmaleimide, aminoethyl acrylate, propylaminoethyl acrylate, dimethylaminoethyl methacrylate, ethylaminopropyl methacrylate, cyclohexylaminoethyl methacrylate, N-vinyldiethylamine, N-acetylvinylamine, Allylamine, methalylamine, N-methylallylamine, 2-isopropenyl-oxazoline, 2-vinyl-oxazoline, 2-acryloyl-oxazoline, N-phenylmaleimide, phenylaminoethyl methacrylate , Styrene, α-methylstyrene, p-glycidyl styrene, p-amino styrene, 2-styryl-oxazoline and the like. These may be used independently and may be used together. Preferably, they are styrene monomers, such as styrene and (alpha) -methylstyrene. The content rate of another vinylic monomer unit becomes like this. Preferably it is 0 to 1 weight%, More preferably, it is 0 to 0.1 weight%. If it is such range, the expression of unwanted phase difference and the fall of transparency can be suppressed.

The imidation ratio in the said acrylic resin becomes like this. Preferably it is 2.5%-20.0%. If the imidation ratio is within this range, a resin excellent in heat resistance, transparency and molding processability can be obtained, and generation of crushing during film molding and reduction of mechanical strength can be prevented. In the said acrylic resin, the imidation ratio is represented by the ratio of a glutarimide unit and an alkyl (meth) acrylate unit. This ratio can be obtained, for example, from an NMR spectrum, an IR spectrum, or the like of an acrylic resin. In this embodiment, the imidation ratio can be calculated | required by ¹ H-NMR measurement of resin using ¹ HNMR BRUKER Avance III (400 MHz). More specifically, the peak area derived from O-CH ₃ protons of alkyl (meth) acrylate near 3.5 to 3.8 ppm is referred to as A, and the peak derived from N-CH ₃ protons of glutarimide near 3.0 to 3.3 ppm is determined. Assuming that the area is B, it is obtained by the following equation.

Imidation ratio Im (%) = {B / (A + B)} × 100

The acid value of the said acrylic resin becomes like this. Preferably it is 0.10 mmol / g-0.50 mmol / g. If the acid value is in this range, a resin having excellent balance of heat resistance, mechanical properties and molding processability can be obtained. If the acid value is too small, problems may arise such as an increase in cost due to the use of a modifier for adjusting to a desired acid value and generation of gelled material due to the remaining of the modifier. If the acid value is too large, foaming at the time of film molding (for example, melt extrusion) tends to occur, and the productivity of the molded article tends to be lowered. In the said acrylic resin, an acid value is content of the carboxylic acid unit and carboxylic anhydride unit in the said acrylic resin. In this embodiment, an acid value can be computed by the titration method as described, for example in WO2005 / 054311 or Unexamined-Japanese-Patent No. 2005-23272.

The weight average molecular weight of the said acrylic resin becomes like this. Preferably it is 1000-2 million, More preferably, it is 5000-1000000, More preferably, it is 10000-500000, Especially preferably, it is 50000-500000, Most preferably, it is 60000-150000. A weight average molecular weight can be calculated | required by polystyrene conversion using gel permeation chromatography (GPC system, the TOSOH CORPORATION make), for example. In addition, tetrahydrofuran can be used as a solvent.

The acrylic resin preferably has a Tg (glass transition temperature) of 110 ° C or more, more preferably 115 ° C or more, even more preferably 120 ° C or more, particularly preferably 125 ° C or more, and most preferably 130 ° C or more. to be. If Tg is 110 degreeC or more, the polarizing plate containing the base film obtained from such resin will become easy to be excellent in durability. Preferably the upper limit of Tg is 300 degrees C or less, More preferably, it is 290 degrees C or less, More preferably, it is 285 degrees C or less, Especially preferably, it is 200 degrees C or less, Most preferably, it is 160 degrees C or less. If Tg is such a range, moldability can be excellent.

B-2-2. Polymerization of Acrylic Resin

The said acrylic resin can be manufactured by the following method, for example. This method copolymerizes (I) an alkyl (meth) acrylate monomer corresponding to the alkyl (meth) acrylate unit represented by General formula (2), an unsaturated carboxylic acid monomer, and / or its precursor monomer, and copolymerizes a copolymer ( to obtain a); And (II) treating the copolymer (a) with an imidating agent to thereby obtain an intramolecular image of the alkyl (meth) acrylate monomer unit and the unsaturated carboxylic acid monomer and / or its precursor monomer unit in the copolymer (a). Conducting a deoxidation reaction and introducing a glutarimide unit represented by the general formula (1) into the copolymer;

As an unsaturated carboxylic acid monomer, acrylic acid, methacrylic acid, crotonic acid, (alpha)-substituted acrylic acid, (alpha)-substituted methacrylic acid is mentioned, for example. As this precursor monomer, acrylamide, methacrylamide, etc. are mentioned, for example. These may be used independently and may be used together. Preferred unsaturated carboxylic acid monomers are acrylic acid or methacrylic acid and preferred precursor monomers are acrylamides.

Arbitrary suitable methods can be used as a method of processing a copolymer (a) with an imidating agent. As a specific example, the method of using an extruder and the method of using a batch reactor (pressure vessel) are mentioned. The method of using an extruder includes heat-melting copolymer (a) using an extruder and treating this with an imidating agent. In this case, any suitable extruder can be used as an extruder. As a specific example, a single screw extruder, a twin screw extruder, and a multi screw extruder are mentioned. In the method of using a batch reactor (pressure vessel), any suitable batch reactor (pressure vessel) can be used.

As an imidation agent, arbitrary appropriate compounds can be used as long as it can produce the glutarimide unit represented by the said General formula (1). Specific examples of the imidizing agent include aliphatic hydrocarbon group-containing amines such as methylamine, ethylamine, n-propylamine, i-propylamine, n-butylamine, i-butylamine, tert-butylamine and n-hexylamine, and aniline And alicyclic hydrocarbon group-containing amines such as aromatic hydrocarbon group-containing amines such as benzylamine, toluidine, trichloroaniline, and cyclohexylamine. In addition, for example, a urea compound which generates such an amine by heating may be used. Examples of the urea compound include urea, 1,3-dimethyl urea, 1,3-diethyl urea and 1,3-dipropyl urea. The imidating agent is preferably methylamine, ammonia, cyclohexylamine, and more preferably methylamine.

In imidation, in addition to the said imidation agent, you may add a ring closure promoter as needed.

The usage-amount of the imidation agent in imidation becomes like this. Preferably it is 0.5 weight part-10 weight part with respect to 100 weight part of copolymers (a), More preferably, it is 0.5 weight part-6 weight part. When the usage-amount of an imidation agent is less than 0.5 weight part, a desired imidation ratio is not achieved in many cases. As a result, the heat resistance of resin obtained becomes very inadequate and may cause an external appearance defect, such as a press after shaping | molding. When the usage-amount of an imidation agent exceeds 10 weight part, the imidation agent will remain in resin, and the said imidation agent may cause appearance defects, such as pressing after molding, and foaming.

The manufacturing method of this embodiment can include the process by an esterifying agent in addition to the said imidation as needed.

As esterification agent, For example, dimethyl carbonate, 2, 2- dimethoxy propane, dimethyl sulfoxide, triethyl orthoformate, trimethyl ortho acetate, trimethyl ortho formate, diphenyl carbonate, dimethyl sulfate, methyl toluene sulfonate, Methyltrifluoromethanesulfonate, methyl acetate, methanol, ethanol, methyl isocyanate, p-chlorophenyl isocyanate, dimethyl carbodiimide, dimethyl-t-butylsilyl chloride, isopropenyl acetate, dimethylurea, tetramethylammonium hydroxide , Dimethyl diethoxysilane, tetra-N-butoxysilane, dimethyl (trimethylsilane) phosphite, trimethyl phosphite, trimethyl phosphate, tricresyl phosphate, diazomethane, ethylene oxide, propylene oxide, cyclohexene oxide, 2- Ethylhexylglycidyl ether, phenylglycidyl There may be mentioned a hotel, benzyl glycidyl ether. Among these, dimethyl carbonate is preferable from the viewpoint of cost and reactivity.

The addition amount of the esterifying agent can be set so that the acid value of the acrylic resin becomes a desired value.

B-2-3. Use of other resin

In embodiment of this invention, you may use together the said acrylic resin and another resin. That is, you may copolymerize the monomer component which comprises acrylic resin, and the monomer component which comprises another resin, and may provide the said copolymer for film formation mentioned later in B-4; Blends of acrylic resins and other resins may be used for film formation. As other resin, for example, styrene resin, polyethylene, polypropylene, polyamide, polyphenylene sulfide, polyether ether ketone, polyester, polysulfone, polyphenylene oxide, polyacetal, polyimide, polyetherimide, etc. And other thermosetting resins such as phenol resins, melamine resins, polyester resins, silicone resins, and epoxy resins. The kind and compounding quantity of resin used together can be suitably set according to the objective and the characteristic desired for the film obtained. For example, styrene resin (preferably acrylonitrile-styrene copolymer) can be used together as a phase difference controlling agent.

When using acrylic resin and another resin together, content of acrylic resin in the blend of acrylic resin and another resin becomes like this. Preferably it is 50 weight%-100 weight%, More preferably, 60 weight%-100 weight%, Furthermore, Preferably it is 70 to 100 weight%, Especially preferably, it is 80 to 100 weight%. When content is less than 50 weight%, there exists a possibility that the high heat resistance and high transparency which an acrylic resin originally has cannot fully be reflected.

B-3. Core Shell Type Particles

In the base film, the core-shell particles are preferably 5 parts by weight to 20 parts by weight, more preferably 5 parts by weight to 13 parts by weight with respect to 100 parts by weight of the acrylic resin. Thereby, the base film which has a desired elastic modulus and suppressed the elution to the surface treatment layer of acrylic resin can be obtained. As a result, the fall of the functionality of the surface treatment layer at the time of forming a surface treatment layer in a base film can be suppressed, and the adhesiveness of a base film and a surface treatment layer can be improved.

The core-shell particles typically have a core composed of a rubbery polymer and a coating layer composed of a glassy polymer to cover the core. The core-shell particles may have at least one layer composed of a glassy polymer as an innermost layer or an intermediate layer.

Tg of the rubbery polymer constituting the core is preferably 20 ° C or lower, more preferably -60 ° C to 20 ° C, and still more preferably -60 ° C to 10 ° C. When Tg of the rubbery polymer which comprises a core exceeds 20 degreeC, there exists a possibility that the improvement of the mechanical strength of acrylic resin may not be enough. Tg of the glassy polymer (hard polymer) which comprises a coating layer becomes like this. Preferably it is 50 degreeC or more, More preferably, it is 50 degreeC-140 degreeC, More preferably, it is 60 degreeC-130 degreeC. When Tg of the glassy polymer which comprises a coating layer is lower than 50 degreeC, there exists a possibility that the heat resistance of acrylic resin may fall.

The content ratio of the core in the core-shell particles is preferably 30% by weight to 95% by weight, more preferably 50% by weight to 90% by weight. The proportion of the glassy polymer layer in the core is 0 to 60% by weight, preferably 0 to 45% by weight, more preferably 10 to 40% by weight relative to 100% by weight of the total amount of the core. The content rate of the coating layer in core-shell particle | grains becomes like this. Preferably it is 5 weight%-70 weight%, More preferably, it is 10 weight%-50 weight%.

In one embodiment, the core-shell particles dispersed in the acrylic resin may have a flat shape. The core-shell particles may be flattened by the stretching described later in section B-4. The length / thickness ratio of the flattened core-shell particles is 7.0 or less. The ratio of length / thickness becomes like this. Preferably it is 6.5 or less, More preferably, it is 6.3 or less. On the other hand, length / thickness ratio becomes like this. Preferably it is 4.0 or more, More preferably, it is 4.5 or more, More preferably, it is 5.0 or more. In this specification, the "ratio of length / thickness" means the ratio of the representative length and the thickness of the shape in the plan view of the core-shell particles. Here, the "representative length" means the diameter when the shape in a plane is circular, the length of the diagonal when it is a long diameter, the rectangle or the polygon when an ellipse is a shape. The said ratio can be calculated | required in the following order, for example. The obtained film cross section was photographed with a transmission electron microscope (for example, acceleration voltage of 80 kPa, RuO ₄ dyeing ultra thin sectioning method), and the longest among the core-shell particles present in the obtained photograph (the cross section close to the representative length can be obtained). The ratio can be obtained by extracting 30 pieces in order from () and calculating (average value of length) / (average value of thickness).

The details of the rubbery polymer constituting the core of the core-shell particles, the glassy polymer (hard polymer) constituting the coating layer, the polymerization method thereof, and other constitutions are described in, for example, Japanese Patent Application Laid-Open No. 2016-33552. have. The description of this publication is incorporated herein by reference.

B-4. Formation of Base Film

The base film by embodiment of this invention is typically by the method containing film forming the composition containing the said acrylic resin (when using other resin together with the said other resin) and core-shell particle | grains. Can be formed. In addition, the method of forming a base film may include extending | stretching the said film.

The average particle diameter of the core-shell particles used for film formation is preferably 1 nm to 500 nm. The average particle diameter of a core becomes like this. Preferably it is 50 nm-300 nm, More preferably, it is 70 nm-300 nm.

Arbitrary appropriate methods can be employ | adopted as a method of forming a film. As a specific example, the cast coating method (for example, casting method), the extrusion molding method, the injection molding method, the compression molding method, the transfer molding method, the blow molding method, the powder molding method, the FRP molding method, the calender molding method, and the hot press method are mentioned. Preferably, it is an extrusion molding method or a cast coating method. It is because the smoothness of the film obtained can be raised and favorable optical uniformity can be obtained. Especially preferably, it is an extrusion molding method. It is because it is not necessary to consider the problem by the residual solvent. Especially, the extrusion method using a T die is preferable from a viewpoint of the productivity of a film and the ease of subsequent extending | stretching process. Molding conditions can be suitably set according to the composition and the kind of resin used, the characteristic desired for the film obtained, etc.

As the stretching method, any suitable stretching method and stretching conditions (for example, stretching temperature, stretching ratio, stretching speed, stretching direction) may be adopted. Specific examples of the stretching method include free end stretching, fixed end stretching, free end contraction, and fixed end contraction. These may be used independently, may be used simultaneously, and may be used in sequence. By extending | stretching the film in which the compounding quantity of the core-shell particle | grains with respect to acrylic resin suitably was adjusted on suitable extending | stretching conditions, the base film which has desired elastic modulus and suppressed the elution of the acrylic resin to the surface treatment layer can be obtained. As a result, the fall of the functionality of the surface treatment layer at the time of forming a surface treatment layer in a base film can be suppressed, and the adhesiveness of a base film and a surface treatment layer can be improved.

As the stretching direction, an appropriate direction may be adopted depending on the purpose. Specifically, a longitudinal direction, a width direction, a thickness direction, and an inclination direction are mentioned. The stretching direction may be one direction (uniaxial stretching), two directions (biaxial stretching), or three or more directions. In embodiment of this invention, uniaxial stretching of the longitudinal direction, simultaneous biaxial stretching of the longitudinal direction and the width direction, and sequential biaxial stretching of the longitudinal direction and the width direction can be employ | adopted. Preferably it is biaxial stretching (simultaneous or sequential). This is because control of the in-plane retardation is easy and optical isotropy is easily realized.

The stretching temperature may vary depending on the optical properties, mechanical properties and thickness desired for the base film, the type of resin used, the thickness of the film used, the stretching method (uniaxial stretching or biaxial stretching), the stretching ratio, the stretching speed, and the like. have. Specifically, the stretching temperature is preferably Tg to Tg + 50 ° C, more preferably Tg + 15 ° C to Tg + 50 ° C, and most preferably Tg + 35 ° C to Tg + 50 ° C. By extending | stretching at such temperature, the base film which has a suitable characteristic can be obtained. Specific drawing temperature is 110 degreeC-200 degreeC, for example, Preferably it is 120 degreeC-190 degreeC. If extending | stretching temperature is such a range, by adjusting draw ratio and draw rate appropriately, the base film which has desired elastic modulus and the elution to the surface treatment layer of acrylic resin can be obtained. As a result, the fall of the functionality of the surface treatment layer at the time of forming a surface treatment layer in a base film can be suppressed, and the adhesiveness of a base film and a surface treatment layer can be improved.

The draw ratio is also changed according to the optical properties, mechanical properties and thickness, the type of resin used, the thickness of the film used, the stretching method (uniaxial stretching or biaxial stretching), the stretching temperature, the stretching speed, and the like as the stretching temperature. Can be. When adopting biaxial stretching, ratio (TD / MD) of the draw ratio of the width direction TD and the draw ratio of the longitudinal direction MD becomes like this. Preferably it is 1.0-1.5, More preferably, it is 1.0-1.4 More preferably, it is 1.0-1.3. In addition, the surface magnification (the product of the draw ratio in the longitudinal direction and the draw ratio in the width direction) in the case of employing biaxial stretching is preferably 2.0 to 6.0, more preferably 3.0 to 5.5, still more preferably 3.5 to 5.2. If the draw ratio is within this range, by appropriately adjusting the draw temperature and the draw speed, the base film having the desired elastic modulus and the elution of the acrylic resin to the surface treatment layer can be obtained. As a result, the fall of the functionality of the surface treatment layer at the time of forming a surface treatment layer in a base film can be suppressed, and the adhesiveness of a base film and a surface treatment layer can be improved.

Similar to the stretching temperature, the stretching speed also varies depending on the optical properties, mechanical properties and thickness, the type of resin used, the thickness of the film used, the stretching method (uniaxial stretching or biaxial stretching), the stretching temperature, the stretching ratio, and the like. Can be. The stretching speed is preferably 3% / second to 20% / second, more preferably 3% / second to 15% / second, and still more preferably 3% / second to 10% / second. When adopting biaxial stretching, the stretching speed in one direction and the stretching speed in another direction may be the same or different. If the extending | stretching speed is such a range, by adjusting draw temperature and a draw ratio suitably, the base film which has a desired elastic modulus and the elution to the surface treatment layer of acrylic resin can be obtained. As a result, the fall of the functionality of the surface treatment layer at the time of forming a surface treatment layer in a base film can be suppressed, and the adhesiveness of a base film and a surface treatment layer can be improved.

As described above, the base film can be formed.

C. Surface Treatment Layer

The surface treatment layer is any suitable functional layer formed on one side of the base film according to the function required for the optical laminate. Specific examples of the surface treatment layer include a hard coat layer, an antiglare layer, an antireflection layer, and the like. The thickness of the surface treatment layer is preferably 3 µm to 20 µm, and more preferably 5 µm to 15 µm.

The surface treatment layer is typically a cured layer of a resin composition formed on a base film. The step of forming the surface treatment layer may include applying a resin composition for forming a surface treatment layer on a base film to form an application layer, and drying and curing the application layer to form a surface treatment layer. Drying and curing the coating layer may include heating the coating layer.

Arbitrary appropriate methods can be employ | adopted as a coating method of a resin composition. For example, the bar coat method, the roll coat method, the gravure coat method, the rod coat method, the slot orifice coat method, the curtain coat method, the fountain coat method, the comma coat method are mentioned. From a viewpoint of making application easy, it is preferable that a resin composition contains the dilution solvent.

The heating temperature of the coating layer is set to any appropriate temperature according to the composition of the resin composition, and preferably, is set below the glass transition temperature of the acrylic resin contained in the base film. When heated to the temperature below the glass transition temperature of acrylic resin contained in a base film, the optical laminated body by which the deformation | transformation by heating was suppressed can be obtained. The heating temperature of an application layer is 50 degreeC-140 degreeC, for example, Preferably it is 60 degreeC-100 degreeC. By heating at such a heating temperature, the optical laminated body excellent in the adhesiveness of a base film and a surface treatment layer can be obtained.

C-1. Hard coat layer

A hard coat layer is a layer which provides scratch resistance, chemical resistance, etc. to the surface of a base film. The hard coat layer preferably has a hardness of at least H, more preferably at least 3H in a pencil hardness test. Pencil hardness test can be measured according to JIS K 5400. The resin composition for hard coat layer formation may contain the curable compound which can be hardened by heat, light (ultraviolet rays, etc.), an electron beam, etc., for example. The detail of the resin composition for hard-coat layer and hard-coat layer formation is described, for example in Unexamined-Japanese-Patent No. 2014-240955. This publication is incorporated herein by reference in its entirety.

C-2. Antiglare layer

An anti-glare layer is a layer for preventing glare of external light by scattering and reflecting light. The resin composition for forming an antiglare layer may include a curable compound that can be cured by heat, light (such as ultraviolet rays) or an electron beam, for example. The antiglare layer typically has a fine concavo-convex shape on its surface. As a method of forming such a fine uneven | corrugated shape, the method of containing microparticles | fine-particles in the said curable compound is mentioned, for example. The detail of the antiglare layer and the resin composition for antiglare layer formation is described, for example in Unexamined-Japanese-Patent No. 2017-32711. This publication is incorporated herein by reference in its entirety.

C-3. Antireflection layer

The antireflection layer is a layer for preventing reflection of external light. The resin composition for antireflection layer formation may contain, for example, a curable compound that can be cured by heat, light (such as ultraviolet rays) or an electron beam. The antireflection layer may be a single layer composed of only one layer or a plurality of layers composed of two or more layers. The detail of the resin composition for antireflection layer and antireflection layer formation is described, for example in Unexamined-Japanese-Patent No. 2012-155050. This publication is incorporated herein by reference in its entirety.

D. Polarizer

The optical laminate according to the above A to C can be applied to the polarizing plate. Therefore, this invention also includes the polarizing plate which used such an optical laminated body. Typically, a polarizing plate has a polarizer and the optical laminated body of this invention arrange | positioned at the one side of a polarizer. The base film side of an optical laminated body sticks with a polarizer, and can function as a protective layer of a polarizer.

Arbitrary suitable polarizers can be employ | adopted as a polarizer. For example, the resin film which forms a polarizer may be a single-layered resin film, and may be a laminated body of two or more layers.

As a specific example of the polarizer comprised from the single-layered resin film, Iodine, a dichroic dye, etc. are used for hydrophilic polymer films, such as a polyvinyl alcohol (PVA) type film, a partially formalized PVA type film, and the ethylene vinyl acetate copolymerization type partial saponification film. And polyene oriented films such as those subjected to dyeing treatment and stretching treatment with a dichroic substance, and dehydration treatment products of PVA and dehydrochlorination treatment products of polyvinyl chloride. Preferably, the polarizer obtained by dyeing a PVA system with iodine and extending | stretching uniaxially from the point which is excellent in an optical characteristic is used.

Dyeing by the said iodine is performed by immersing a PVA system film in aqueous solution of iodine, for example. The draw ratio of the uniaxial stretching is preferably 3 to 7 times. Stretching may be performed after the dyeing treatment or may be performed while dyeing. Moreover, you may dye after extending | stretching. As needed, a swelling process, a crosslinking process, a washing process, a drying process, etc. are given to a PVA system film. For example, by immersing the PVA-based film in water prior to dyeing and washing with water, not only the contamination of the surface of the PVA-based film and the blocking agent can be washed, but also the swelling of the PVA-based film can prevent dyeing unevenness.

As a specific example of the polarizer obtained using a laminated body, the laminated body of a resin base material and the PVA system resin layer (PVA system resin film) laminated | stacked on the said resin base material, or the laminated body of the resin base material and the PVA system resin layer apply | coated and formed in the said resin base material. The polarizer obtained using is mentioned. The polarizer obtained using the laminated body of the resin base material and the PVA-type resin layer apply | coated to the said resin base material apply | coats a PVA-type resin solution to a resin base material, it dries, and forms a PVA-type resin layer on a resin base material, for example, Obtaining a laminate of a resin substrate and a PVA resin layer; The laminate may be stretched and dyed to produce a PVA resin layer as a polarizer. In this embodiment, extending | stretching typically includes extending | stretching and immersing a laminated body in boric-acid aqueous solution. In addition, extending | stretching may further include carrying out air extension of a laminated body at high temperature (for example, 95 degreeC or more) before extending | stretching in boric-acid aqueous solution as needed. The obtained laminate of the resin substrate / polarizer may be used as it is (that is, the resin substrate may be used as a protective layer of the polarizer), the resin substrate is peeled from the laminate of the resin substrate / polarizer, and any desired purpose is applied to the peeling surface. An appropriate protective layer of may be laminated. The detail of the manufacturing method of such a polarizer is described, for example in Unexamined-Japanese-Patent No. 2012-73580. This publication is incorporated herein by reference in its entirety.

The thickness of a polarizer is 1 micrometer-80 micrometers, for example. In one embodiment, the thickness of a polarizer becomes like this. Preferably it is 2 micrometers-30 micrometers, More preferably, it is 3 micrometers-25 micrometers.

E. Image Display Device

The polarizing plate described in the above section D can be applied to an image display device. Therefore, the present invention also includes an image display device using such a polarizing plate. Representative examples of the image display device include a liquid crystal display device and an organic electroluminescent (EL) display device. Since the image display apparatus employs a structure well known in the art, details are omitted.

Example

Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by these Examples. The measuring method of each characteristic is as follows. In addition, "part" and "%" in an Example are a basis of weight unless there is particular notice.

(1) The ratio of the component of the acrylic resin eluted to the surface treatment layer

The ratio of the component of the acrylic resin eluted to the surface treatment layer was measured by the method of using the three-dimensional optical refractive index and film thickness measuring device prism coupler (Metricon, Metricon 2010 / M). The refractive index measurement using the prism coupler was performed on condition of the following.

·Measuring conditions

Light source: 594nm

Mode: TE

Scan: 300 ~ -300

(1-1) Refractive Index R1 of the Base Film

Measurement type: Bulk / Substrate

The mode (called "Knee") was detected by the measurement of a base film. The refractive index obtained by the measurement was set to R1.

(1-2) Refractive Index R2 of the Surface Treatment Layer

Measurement type: Single Film (Prism Couple)

Except having made the heating temperature of an application layer into 60 degreeC using PET base material (made by Toray Industries, Inc., brand name: U48-3, refractive index: 1.60) as a base film, it carried out similarly to each Example similarly to each Example. The laminated body of thickness was obtained. The plurality of modes were detected by measuring this laminate in the Single Film mode. The refractive index obtained by the measurement was set to R2.

(1-3) Refractive index R3 in the depth position of 3.0 micrometers in the direction of a surface treatment layer from the base film side

Measurement type: Single Film (Prism Couple)

Analysis Method: Index gradient

When the refractive index changes in the depth direction in the optical laminate, the change in the refractive index in the depth direction can be quantitatively obtained by the method using the prism coupler.

The several modes were detected by the measurement of an optical laminated body, and the refractive index change with respect to the depth direction was computed by Index gradient analysis. From the base film side, in the direction of a surface treatment layer, the "3.0 micrometer depth position" was determined based on the following formula, and the refractive index obtained was made into R3.

"Depth position of 3.0 micrometers" (position from the surface treatment side) = surface treatment layer thickness (PET base material hard coat thickness)-(3 micrometers)

(1-4) The ratio X of the component of the acrylic resin eluted to the surface treatment layer among the components which comprise a depth position of 3.0 micrometers from the base film side in the direction of a surface treatment layer.

From the following formula | equation, the ratio X (%) of the component of the acrylic resin eluted to the surface treatment layer among the components which comprise a 3.0 micrometers depth position in the direction of a surface treatment layer from the base film side was computed.

X (%) = (R3-R2) × 100 / (R1-R2)

(2) elastic modulus of the base film

TI900 TriboIndenter (manufactured by Hysitron) was used for measuring the elastic modulus of the base film. The base film was cut into the size of 10 mm x 10 mm, and it fixed to the support body equipped with TriboIndenter, and the compressive elastic modulus was measured by the nano indentation method. At that time, the position was adjusted so as to press-in the vicinity of the center of the transparent layer. Measurement conditions are shown below.

Indenter: Berkovich

Measurement Method: Single Indentation Measurement

Measuring temperature: 25 ℃

Indentation Depth: 500 nm

Indentation Speed: 100nm / s

(3) Functional evaluation of the surface treatment layer

The optical laminated body obtained by the Example and the comparative example was cut | disconnected to the magnitude | size of width 11mm and length 100mm, and the base film was put down and placed on the glass plate. Subsequently, on the surface treatment layer (hard coat layer) side surface of the said optical laminated body, steel wool # 0000 affixed to the cross section of the cylinder of diameter 11mm was reciprocated 10 times by the load of 800g or 600g, 100mm / sec. The hard-coat layer side surface after that was visually observed, and the following references | standards evaluated.

○: no scratch at all

△: There was a little wound

X: a wound is remarkable

(4) adhesion evaluation

The adhesiveness with respect to the base film of a surface treatment layer was evaluated based on the checkerboard scale peeling test (checkerboard number: 100 pieces) of JISK-5400, and was determined by the following indicators.

○: 0 checkerboard peelings

×: 1 or more checkerboard peeling number

<Example 1>

1. Production of base film

MS resin (MS-200; copolymer of methyl methacrylate / styrene (molar ratio) = 80/20, manufactured by Nippon Steel Chemical Co., Ltd.) was imidized (imidization rate: 5%) in monomethylamine. . The obtained imidized MS resin is a glutarimide unit represented by General Formula (1) (R ¹ and R ³ are methyl groups, R ² is a hydrogen atom), and a (meth) acrylic acid ester unit represented by General Formula (2) ( R ⁴ and R ⁵ are methyl groups) and styrene units. In addition, the said imidation used the interlocking coaxial rotary twin screw extruder of diameter 15mm. MS resin was supplied at 2.0 kg / hr by setting the set temperature of each temperature control zone of the extruder to 230 degreeC, and 150 rpm of screw rotations, and the supply amount of monomethylamine was 2 weight part with respect to 100 weight part of MS resin. MS resin was thrown in from the hopper, the resin was melted and filled with a kneading block, and then monomethylamine was injected from the nozzle. Sealing was put at the end of the reaction zone to fill the resin. The by-product after reaction and excess methylamine were devolatilized by reducing the pressure of the vent port to -0.08 MPa. The resin which came out as a strand from the dice | dies installed at the exit of the extruder was cooled in the water tank, and then pelletized with the pelletizer. The imidation ratio of the obtained imidation MS resin was 5.0%, and the acid value was 0.5 mmol / g.

100 parts by weight of the imidized MS resin and 5 parts by weight of the core-shell particles obtained above were introduced into a single screw extruder, melt mixed, and a film was formed through a T die to obtain an extruded film. The obtained extruded film was simultaneously biaxially stretched twice in the longitudinal direction and the width direction at the stretching temperature of 140 ° C. The stretching speed was 10% / second in both the longitudinal direction and the width direction.

Thus, the base film A of thickness 30micrometer was produced.

2. Fabrication of Optical Laminates

On one side of the base film A, 16 parts by weight of a UV curable resin (4-HBA (manufactured by Osaka Organic Chemical Industry Ltd.)), NK oligo UA-53H-80BK (Shin-Nakamura Chemical Co. , Ltd.) 32 parts by weight, Bis coat # 300 (manufactured by Osaka Organic Chemical Industry Ltd.) 48 parts by weight, 4 parts by weight of A-GLY-9E (manufactured by Shin-Nakamura Chemical Co., Ltd.), IRGACURE 907 2.4 parts by weight of BASF) were mixed, and diluted with a solvent of MIBK: PGM = 50: 50, respectively, so as to have a solid content concentration of 42.0%). Subsequently, the said coating layer was dried at 70 degreeC, and also UV hardened | cured, and the optical laminated body 1 in which the hard-coat layer was formed in the one side of the base film A was obtained. The said optical laminated body 1 was provided for each evaluation. The results are shown in Table 1.

<Example 2>

1. Production of base film

The base film B was produced like Example 1 except having set the compounding quantity of a core-shell particle into 10 weight part, and extending | stretching temperature of the extruded film into 150 degreeC.

2. Fabrication of Optical Laminates

Except having used the said base film B, the optical laminated body 2 in which the hard-coat layer was formed in the one side of the base film B similarly to Example 1 was obtained. The said optical laminated body 2 was provided for each evaluation. The results are shown in Table 1.

<Example 3>

1. Production of base film

The base film C was produced like Example 1 except having set the compounding quantity of a core-shell particle into 10 weight part, and extending | stretching temperature of the extruded film into 160 degreeC.

2. Fabrication of Optical Laminates

Except having used the said base film C, the optical laminated body 3 in which the hard-coat layer was formed in the one side of the base film C similarly to Example 1 was obtained. The said optical laminated body 3 was provided for each evaluation. The results are shown in Table 1.

<Example 4>

1. Production of base film

Substrate film D was produced in the same manner as in Example 1 except that the blending amount of the core-shell particles was 13 parts by weight, and the stretching temperature of the extruded film was 152 ° C.

2. Fabrication of Optical Laminates

Except having used the said base film D, it carried out similarly to Example 1, and obtained the optical laminated body 4 in which the hard-coat layer was formed in the one side of the base film D. The said optical laminated body 4 was provided for each evaluation. The results are shown in Table 1.

Comparative Example 1

1. Production of base film

100 parts by weight of the imidized MS resin and 15 parts by weight of the core-shell particles obtained above were introduced into a single screw extruder, melt mixed, and a film was formed through a T die to obtain an extruded film. The obtained extruded film was simultaneously biaxially stretched twice in the longitudinal direction and the width direction at the stretching temperature of 152 ° C. The stretching speed was 10% / second in both the longitudinal direction and the width direction.

Thus, the base film E of thickness 40micrometer was produced.

2. Fabrication of Optical Laminates

Except having used the said base film E, the optical laminated body 5 in which the hard-coat layer was formed in the one side of the base film E similarly to Example 1 was obtained. The said optical laminated body 5 was provided for each evaluation. The results are shown in Table 1.

Comparative Example 2

1. Production of base film

100 parts by weight of the imidized MS resin and 23 parts by weight of the core-shell particles obtained above were introduced into a single screw extruder, melt-mixed, and a film was formed through a T die to obtain an extruded film. The obtained extruded film was simultaneously biaxially stretched twice in the longitudinal direction and the width direction at the stretching temperature of 137 ° C. The stretching speed was 10% / second in both the longitudinal direction and the width direction.

Thus, the base film F of thickness 40micrometer was produced.

2. Fabrication of Optical Laminates

Except having used the said base film F, the optical laminated body 6 in which the hard-coat layer was formed in the one side of the base film F similarly to Example 1 was obtained. The said optical laminated body 6 was provided for each evaluation. The results are shown in Table 1.

Comparative Example 3

1. Production of base film

The base film G was produced like Example 1 except not having mix | blended core shell type particle | grains, and extending | stretching temperature of the extruded film being 130 degreeC.

2. Fabrication of Optical Laminates

Except having used the said base film G, the optical laminated body 7 in which the hard-coat layer was formed in the one side of the base film G similarly to Example 1 was obtained. The said optical laminated body 7 was provided for each evaluation. The results are shown in Table 1.

As is apparent from Table 1, the proportion of the component of the acrylic resin eluted to the surface treatment layer among the components constituting a depth position of 3.0 µm in the direction of the surface treatment layer having a modulus of elasticity of 4 GPa or more is 20%. The optical laminated bodies of Examples 1-4 using less than the base film were excellent in scratch resistance and adhesiveness.

(Industrial availability)

The optical laminated body of this invention is used suitably as a protective layer of a polarizer. The polarizing plate which has the optical laminated body of this invention as a protective layer is used suitably for an image display apparatus. Such an image display apparatus includes a portable device such as a portable information terminal (PDA), a smartphone, a cellular phone, a clock, a digital camera, a portable game machine, and the like; OA devices such as PC monitors, notebooks, and copiers; Household electrical appliances such as video cameras, televisions, and microwave ovens; On-vehicle devices such as a back monitor, a car navigation system monitor, and car audio; Display devices such as digital signage and information monitors for commercial stores; Security devices such as monitoring monitors; Nursing care and medical devices such as nursing monitors and medical monitors; It can be used for various uses such as.

10 base film
20 surface treatment layer
100 optical stack

Claims (9)

A base film and a surface treatment layer formed on one side of the base film,
The base film includes an acrylic resin and core-shell particles dispersed in the acrylic resin,
The elasticity modulus of the said base film is 4.0 GPa or more,
The optical laminated body whose ratio of the component of the said acrylic resin eluted to the said surface treatment layer among the components which comprises a depth position of 3.0 micrometers in the direction of the said surface treatment layer from the said base film side is less than 20%. The method of claim 1,
When the refractive index of the said base film is called R1, the refractive index of the said surface treatment layer is called R2, and the refractive index in the depth position of 3.0 micrometers from the said base film side in the direction of the said surface treatment layer is set to R3,
Optical laminated body which satisfy | fills R3> 0.2R1 + 0.8R2 (it is called R1 <R2). The method according to claim 1 or 2,
The optical laminated body whose thickness of the said surface treatment layer is 3 micrometers-20 micrometers. The method according to any one of claims 1 to 3,
The said base film contains 5 weight part-20 weight part of the said core-shell particles with respect to 100 weight part of said acrylic resins. The method according to any one of claims 1 to 4,
The optical laminated body which has at least 1 chosen from the group which the said acrylic resin consists of a glutarimide unit, a lactone ring unit, a maleic anhydride unit, a maleimide unit, and a glutaric anhydride unit. The method according to any one of claims 1 to 5,
The optical laminated body whose said surface treatment layer is a hardened layer of resin apply | coated on the said base film. The method according to any one of claims 1 to 6,
The optical laminated body whose said surface treatment layer is at least 1 chosen from the group which consists of a hard-coat layer, an anti-glare layer, and an antireflection layer. It includes a polarizer and a protective layer disposed on one side of the polarizer,
The polarizing plate whose said protective layer is the optical laminated body in any one of Claims 1-7. An image display apparatus provided with the polarizing plate of Claim 8.

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