TWI519826B - Antiglare hard coat film and polarizing plate using the film - Google Patents

Description

Anti-glare hard coating film and polarizing plate using the same

The present invention relates to an antiglare hard coating film and a polarizing plate using the hard coating film. More specifically, the present invention relates to an antiglare hard coating film and a polarizing plate using the same, which comprises a hard coat layer containing organic fine particles, wherein a hard coat layer is provided The total fog value and the "total fog value - internal fog value" are specified values, which can reduce fading and contrast reduction, and also have high image clarity and appropriate anti-glare.

In a display such as a cathode ray tube (CRT) or a liquid crystal display (LCD) or a plasma display (PDP), light is incident on the screen from the outside, and the light is reflected, which makes it difficult to see the display image, particularly with recent displays. The enlargement of the above problems has become an increasingly important issue. As a means for solving this problem, a member using an antiglare hard coat layer can be cited. Further, the method for forming the antiglare hard coat layer can be classified into the following three types: (1) a method of roughening a surface by physical means in forming a hard coat layer; (2) a method of forming a hard coat layer. A method of mixing a filler in a hard coating agent; (3) mixing two components which are immiscible in a hard coating agent for forming a hard coat layer, and using a phase separation method thereof. In these methods, fine irregularities are formed on the surface to suppress specular reflection of external light, and to prevent reflection of external light such as a fluorescent lamp. Among these methods, the mainstream method is (2) a method of mixing a filler in a hard coating agent. As the filler, inorganic fine particles typified by the original vermiculite are generally used. The reason why the vermiculite particles are used is exemplified by insufficient hardening of the hard coat layer, resulting in low abrasion resistance and the like.

On the other hand, using organic fine particles as a filler, for example, Patent Document 1 discloses an abrasion-resistant anti-glare film which is formed on a transparent substrate by a resin bead substantially having a refractive index of 1.40 to 1.60. And an anti-glare layer formed of an ionizing radiation-curable resin composition; and Patent Document 2 discloses an anti-glare film comprising a transparent base film and two kinds of translucent resin. The antiglare layer formed of the above-mentioned light-transmitting fine particles is configured such that the difference in refractive index between the light-transmitting fine particles and the light-transmitting resin is 0.03 or more and 0.20 or less, and the light-transmitting fine particles of the above two or more types are on the surface of the anti-glare layer. It is formed by forming a concave-convex shape.

However, it is disadvantageous to provide such an anti-glare hard coat layer for the purpose of clearly seeing the image reflected from the screen. The anti-glare hard coat layer has a property of transmitted light scattering due to unevenness of its surface, and as a result, there is a problem that image sharpness is lowered and visibility is lowered. In addition, since the whitish color called fading is reduced, the black density is lowered, thereby having a problem of lowering the contrast ratio; on the other hand, if the surface unevenness is reduced in order to improve the sharpness and fading of the image, it is impossible to prevent the fluorescent lamp and the external light. The problem of reflection.

On the other hand, an anti-glare hard coating film which is excellent in anti-glare property, prevents glare, and prevents whitening, and has excellent display contrast at a bright position, discloses an anti-glare hard coating film. An anti-glare hard coating film having an anti-glare hard coat layer containing fine particles on at least one surface of a transparent plastic film substrate, wherein the anti-glare hard coat layer has a concave-convex structure, and the total haze value ht is In the range of 40 to 70%, the relationship between the total haze value ht and the internal haze value hi caused by the internal scattering of the anti-glare hard coat layer is the total haze value ht The relationship of the internal haze value hi (refer to Patent Document 3).

[Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 6-18706

[Patent Document 2] Japanese Patent No. 3515401

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2007-334294

However, the technique described in the above Patent Document 3 defines the relationship between the total haze value ht and the internal haze value hi as "total haze value ht ≦ internal haze value hi" to prevent glare, and to prevent whitening and improve the bright position. The contrast is displayed, but the relationship between the total haze value ht and the internal haze value hi is defined in a high range in which the total haze value of the poor visibility is 40 to 70%.

The present invention has been made in view of such problems, and an object thereof is to provide an anti-glare hard coating film which can reduce fading and low contrast, and which has high image clarity and appropriate anti-glare property; And a polarizing plate using the antiglare hard coating film.

In order to achieve the above object, the present inventors have conducted intensive studies to find an anti-glare hard coating film which has an active energy ray-inducing composition and a spherical organic particle on the surface of a transparent plastic film. The hard coat layer forms a hard coat layer formed of a material, and the total haze value of the hard coat layer is less than a specific value, and the value of "total haze value - internal haze value" is formed in a specific range, thereby achieving the above object. The present invention has been completed based on this recognition.

That is, the present invention provides:

[1] An anti-glare hard coating film characterized in that a surface of a transparent plastic film has a hard coat layer formed using a hard coat forming material, and the hard coat layer forming material contains (A) an active energy ray-inductive type combination And (B) spherical organic fine particles, and the total haze value of the hard coat layer is 20% or less, and the value of "total haze value - internal haze value" is in the range of -10 to +1%;

[2] The anti-glare hard coating film according to [1], wherein the spherical organic fine particles of the component (B) have an average particle diameter of 1 to 10 μm;

[3] The antiglare hard coating film according to the above [1] or [2] wherein the specular gloss of 60° is 150 or less;

[4] The anti-glare hard coating film according to any one of [1] to [3] wherein the surface of the hard coat layer has an arithmetic mean roughness Ra of 0.02 to 0.30 μm;

[5] The antiglare hard coating film according to any one of the above [1], wherein the hard coat layer has a surface resistivity of 10 ¹³ Ω/□ or less;

[6] A polarizing plate which is formed by bonding a polarizing plate to a surface on a side opposite to a hard coat layer forming surface of the antiglare hard coating film according to any one of the above [1] to [5] .

Further, as a preferred aspect of the antiglare hard coating film of the present invention, there are mentioned:

(a) an anti-glare hard coating film having a total image sharpness of 5 or more slits of 300 or more;

(b) (B) the content of the spherical organic fine particles is 0.1 to 30 parts by mass of the anti-glare hard coating film with respect to 100 parts by mass of the solid substance of the (A) active energy ray-sensitive composition;

(c) (A) an active energy ray-sensitive composition comprising an anti-glare hard coating film of a compound containing a quaternary ammonium base;

(d) An anti-glare hard coating film having a difference between the refractive index of the cured product of the active energy ray-sensitive composition and the refractive index of the spherical organic fine particles of 0.01 to 0.05 in absolute value.

According to the present invention, there is provided an antiglare hard coating film and a polarizing plate using the antiglare hard coating film, wherein the hard coating film is an antiglare hard coating film formed by providing a hard coat layer containing spherical organic fine particles, The total haze value of the hard coat layer and the "total haze value - internal haze value" are specific values, which can reduce fading or contrast reduction, and also have high image clarity and appropriate anti-glare property.

In the antiglare hard coating film of the present invention, when a hard coat layer provided on at least one surface of the transparent plastic film is formed, a hard coat layer forming material having the following composition is used.

[hard coating forming material]

The hard coat layer forming material in the present invention comprises (A) an active energy ray-sensitive composition and (B) spherical organic fine particles.

((A) Active energy ray-sensitive composition)

In the above-mentioned hard coat layer forming material, as the active energy ray-sensitive composition used as the component (A), it is preferred to use (a) a polyfunctional (meth) acrylate monomer and/or (A) A material based on an acrylate prepolymer and (b) vermiculite particles used as needed.

Further, in the present invention, the active energy ray means an electromagnetic wave or a charged particle beam having an energy sub-particle, that is, an ultraviolet ray, an electron beam, or the like.

<(a) Polyfunctional (meth) acrylate monomer and/or (meth) acrylate prepolymer>

In the present invention, as the (A) active energy ray-sensitive composition, a polyfunctional (meth) acrylate monomer and/or a (meth) acrylate prepolymer (hereinafter sometimes referred to as As an active energy ray-curable compound).

Examples of the polyfunctional (meth)acrylate monomer include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol (meth)acrylate, and neopenta-2. Alcohol di(meth)acrylate, polyethylene glycol di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, dicyclopentyl di(meth)acrylate, Caprolactone-modified dicyclopentene di(meth)acrylate, ethylene oxide-modified di(meth)acrylate, allylated cyclohexyl di(meth)acrylate, isocyanide Urea di(meth)acrylate, trimethylolpropane tri(meth)acrylate, diquaternary pentaerythritol tri(meth)acrylate, propionic acid modified diquaternary pentaerythritol III (Meth) acrylate, quaternary pentylene glycol tri(meth) acrylate, propylene oxide modified trimethylolpropane tri(meth) acrylate, tris(propylene decyloxyethyl) isocyanate Urea, propionic acid modified ditetrapentaerythritol penta(meth)acrylate, diquaternary pentaerythritol hexa(meth)acrylate, caprolactone modified diquaternary pentaerythritol Polyfunctional (methyl) acrylate Enoate. These monomers may be used alone or in combination of two or more.

On the other hand, examples of the (meth) acrylate-based prepolymer include polyester acrylates, epoxy acrylates, urethane acrylates, and polyol acrylates. Wherein, as the polyester acrylate-based prepolymer, for example, a hydroxyl group of a polyester oligomer having a hydroxyl group at both terminals obtained by condensing a polyvalent carboxylic acid and a polyhydric alcohol may be esterified with (meth) acrylate; or The hydroxyl group at the terminal of the oligomer obtained by adding an alkylene oxide to a polyvalent carboxylic acid is obtained by esterification with (meth)acrylic acid.

The epoxy acrylate-based prepolymer can be obtained, for example, by reacting an oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or a novolac type epoxy resin with (meth)acrylic acid to obtain an esterification. The urethane acrylate prepolymer can be obtained, for example, by esterification of a polyurethane oligomer obtained by reacting a polyester polyol or a polyester polyol with a polyisocyanate with (meth)acrylic acid. Further, the polyol acrylate prepolymer can be obtained by esterifying a hydroxyl group and a (meth) acrylate of a polyether polyol. These prepolymers may be used alone or in combination of two or more, or may be used together with the above polyfunctional (meth)acrylate monomers.

<(b) Vermiculite particles>

In the present invention, gel-like vermiculite particles and/or vermiculite particles having surface functional groups may be used as the (b) vermiculite-based fine particles to be used.

The gelatin-like vermiculite particles have an average particle diameter of about 1 to 400 nm, and examples of the vermiculite particles having a surface functional group include vermiculite particles having a group containing a (meth)acryl fluorenyl group as a surface functional group. (hereinafter, referred to as reactive vermiculite particles).

The reactive vermiculite fine particles can be obtained, for example, by reacting a stanol group on the surface of vermiculite particles having an average particle diameter of about 0.005 to 1 μm with an organic compound containing a polymerizable unsaturated group having a functional group reactive with the stanol group. . The polymerizable unsaturated group may, for example, be a radically polymerizable (meth) acrylonitrile group.

As the organic compound containing a polymerizable unsaturated group having a functional group reactive with the above stanol group, for example, acrylic acid, acrylonitrile chloride, ethyl 2-isocyanate, glycerin acrylate, acrylic acid 2, 3 are preferably used. - iminopropyl acrylate, 2-hydroxyethyl acrylate, propylene methoxy propyl trimethoxy decane, and the like, and methacrylic acid derivatives corresponding to these acrylic acid derivatives. These acrylic acid derivatives or methacrylic acid derivatives may be used singly or in combination of two or more.

The vermiculite particles obtained by combining the organic compound containing a polymerizable unsaturated group thus obtained are used as an active energy ray-curable compound, and are crosslinked and hardened by irradiation with an active energy ray.

Such a reactive vermiculite particle has an effect of improving the abrasion resistance of the obtained hard coating film.

As the active energy ray-sensitive composition (A) containing a compound formed by binding an organic compound having a polymerizable unsaturated group to such vermiculite particles, for example, the product name "Opstar" manufactured by JSR Co., Ltd. is commercially available. Z7530", "Opstar Z7524", "Opstar TU4086", etc.

In the present invention, the content of the vermiculite-based fine particles of the component (b) is usually from 5 to 90% by mass, preferably from 10 to 90% by mass in the solid content of the active energy ray-sensitive composition of the component (A). 70% by mass or so.

Further, the average particle diameter of the vermiculite particles in the vermiculite particles of the component (b) can be measured by a laser diffraction-scattering method. In this method, the average particle diameter is determined by the intensity change of the diffracted and scattered light when the laser is contacted in the liquid in which the particles are dispersed.

((B) spherical organic particles)

In the hard coat layer forming material of the present invention, the spherical organic fine particles used as the component (B) include, for example, anthrone-based fine particles, melamine-based fine particles, and acrylic fine particles (for example, polymethacrylic acid can be cited) Ester fine particles (hereinafter sometimes referred to as PMMA-based fine particles), acrylic acid-styrene copolymer fine particles, polycarbonate fine particles, polyethylene fine particles, polystyrene fine particles, benzoguanamine resin fine particles, and the like .

In the present invention, organic fine particles are used in order to uniformize the light scattering state of the spherical fine particles from the viewpoint of quality stability of the antiglare performance. The average particle diameter of the spherical organic fine particles is preferably from 1 to 10 μm; if the average particle diameter is less than 1 μm, fading or the like may occur, and if it exceeds 10 μm, the antiglare property may be insufficient. From this point of view, the average particle diameter is particularly preferably 2 to 8 μm.

In the present invention, the spherical organic fine particles of the component (B) may be used singly or in combination of two or more kinds thereof, and the amount of the mixture may be used as the above (A) with respect to 100 parts by mass from the viewpoint of antiglare performance. The solid content of the active energy ray-sensitive composition of the component is preferably from 0.1 to 30 parts by mass, more preferably from 1 to 20 parts by mass.

Further, in order to make the total haze value to be described later 20% or less, the value of "total haze value - internal haze value" is in the range of -10 to +1%, and the refractive index of the cured product of the active energy ray-sensitive composition is The difference in refractive index of the spherical organic fine particles is preferably 0.01 to 0.05 in terms of an absolute value. Thereby, it is possible to obtain an anti-glare hard coating film having high transmission clarity without fading or the like while having sufficient anti-glare performance.

In the antiglare hard coating film of the present invention, when the hard coat layer is required to have antistatic properties, it is preferred to add a quaternary ammonium base-containing compound to the (A) active energy ray-sensitive composition. The quaternary ammonium base-containing compound may contain (1) an active energy ray-curable compound capable of copolymerizing with an active energy ray-curable compound in the composition by applying an active energy ray, that is, a quaternary ammonium-containing compound. Monomer; or (2) a polymer containing a quaternary ammonium base.

The quaternary ammonium base-containing monomer of the above (1) may, for example, be a compound represented by the formula (1).

In the formula, R represents a hydrogen atom or a methyl group.

In the present invention, the quaternary ammonium base-containing monomer may be used singly or in combination of two or more.

By including the quaternary ammonium base-containing monomer in the active energy ray-sensitive composition of the component (A), the active energy ray-curable compound and the above-mentioned four contained in the composition can be applied by applying an active energy ray. The monomer of the ammonium chloride is copolymerized, and a quaternary ammonium base is introduced into the obtained hardened resin.

On the other hand, as the quaternary ammonium base-containing polymer of the above (2), for example, a polymer having a quaternary ammonium base represented by the formula (2) in a molecule is preferable.

(wherein R ¹ and R ² each independently or differently represent an alkyl group having 1 to 10 carbon atoms, and R ³ represents an alkyl group having 1 to 10 carbon atoms or an aralkyl group having 7 to 10 carbon atoms; Base, X ^n- represents an n-valent anion, and n represents an integer from 1 to 4)

In the above formula (2), the alkyl group represented by R ¹ and R ^{2 and} the alkyl group in R ³ are preferably an alkyl group having 1 to 6 carbon atoms, particularly 1 to 4 carbon atoms. Further, as the aralkyl group in R ³ , a benzyl group is preferred. Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a secondary butyl group, and a tertiary butyl group.

On the other hand, X ^n- may be any of an inorganic anion or an organic anion, and examples thereof include halogen anions of F ^- , Cl ^- , Br ^- , and I ^- NO ₃ ^- , ClO ₄ ^- , and BF _{4 .} ^{- an} inorganic anion such as CO ₃ ^2- or SO ₄ ^2- , CH ₃ OSO ₃ ^- , C ₂ H ₅ OSO ₃ ^- , and from acetic acid, malonic acid, succinic acid, maleic acid, fumaric acid, p-toluene An organic anion formed by residues of an organic acid such as sulfonic acid or trifluoroacetic acid.

Examples of such a quaternary ammonium base-containing polymer include compounds exemplified below, that is, polyvinylbenzyl type [(a)], poly(meth)acrylate type [(b)], and benzene. Ethylene-(meth)acrylate copolymer type [(c)], styrene-maleimide copolymer type [(d)], methacrylate-methacrylimide copolymer type [( e)] and so on. Further, in the types of copolymers of (c), (d) and (e), it may be any of a random copolymer type and a block copolymer type.

In the present invention, the quaternary ammonium base-containing polymer may be used singly or in combination of two or more.

The content of the quaternary ammonium base in the hard coat layer is not particularly limited, and may be appropriately selected so that the surface resistivity of the hard coat layer is a desired value.

It is presumed that by containing the above-mentioned monomer or polymer having a quaternary ammonium base (a compound containing a quaternary ammonium base) in the hard coat layer forming material, the monomer or polymer functions similarly to the cationic surfactant. When the hard coat layer forming material is applied to the surface of the transparent plastic to form a wet coating film, it is presumed that the dispersibility of the spherical organic fine particles in the wet coating film is improved, whereby the obtained antiglare hard coating film exhibits good adhesion. Anti-glare and high image clarity.

(photopolymerization initiator)

In the hard coat layer forming material of the present invention, a photopolymerization initiator may be contained as desired. Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, and benzoin isobutyl ether. , acetophenone, dimethylaminoethyl benzene, 2,2-dimethoxy-2-phenyl acetophenone, 2,2-diethoxy-2-phenyl acetophenone, 2- Hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholine -propan-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)one, benzophenone, p-phenylbenzophenone, 4,4' -diethylaminobenzophenone, dichlorobenzophenone, 2-methyloxime, 2-ethylhydrazine, 2-tributylphosphonium, 2-aminopurine, 2 -methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethyl A ketal, an acetophenone ketal, a p-dimethylamino benzoate or the like.

These may be used alone or in combination of two or more. Further, the compounding amount thereof is usually selected in the range of 0.2 to 10 parts by mass based on 100 parts by mass of the total active energy ray-curable compound.

(Preparation of hard coat forming material)

The hard coat layer forming material used in the present invention is added to the active energy ray-sensitive composition of the above component (A), the organic fine particles of the component (B), and, if desired, in a predetermined ratio in a suitable solvent. The photopolymerization initiator to be used and various additives such as an antioxidant, an ultraviolet absorber, a decane coupling agent, a light stabilizer, a leveling agent, a defoaming agent, and the like are dissolved or dispersed to prepare.

Examples of the solvent to be used in this case include aliphatic hydrocarbons such as hexane and heptane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as dichloromethane and dichloroethane, methanol, ethanol, propanol and butanol. An alcohol such as propylene glycol monomethyl ether, a ketone such as acetone, methyl ethyl ketone, 2-pentanone, isophorone or cyclohexanone; an ester such as ethyl acetate or butyl acetate; and a cellosolve solvent such as ethyl cellosolve. Wait.

The concentration and viscosity of the hard coat layer forming material thus prepared are not particularly limited as long as they can be applied, and may be appropriately selected depending on the case.

[Transparent plastic film]

In the antiglare hard coating film of the present invention, the hard coat layer forming material prepared as described above is formed on at least one surface of the transparent plastic film to form a hard coat layer.

The transparent plastic film is not particularly limited, and can be suitably selected from plastic films known as substrates for optical hard coating films. Examples of such a plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyethylene film, polypropylene film, and cellophane. a diacetyl cellulose film, a triethylene glycol cellulose film (hereinafter sometimes referred to as "TAC film"), an ethylene glycol cellulose butyrate film, a polyvinyl chloride film, a polyvinylidene chloride film, Polyvinyl alcohol film, ethylene-vinyl acetate copolymer film, polystyrene film, polycarbonate film, polymethylpentene film, polyfluorene film, polyetheretherketone film, polyether enamel film, polyether enamel A plastic film such as an amine film, a polyimide film, a fluororesin film, a polyamide film, an acrylic film, a norbornane resin film, or a cycloolefin resin film.

These plastic films are preferably transparent films.

The thickness of these plastic films is not particularly limited and may be appropriately selected depending on the case, and is usually in the range of 15 to 300 μm, preferably 30 to 200 μm. Further, the plastic film is subjected to surface treatment on one or both sides by an oxidation method, an unevenness method, or the like for the purpose of improving the adhesion of the antiglare hard coat layer. Examples of the oxidation method include corona discharge treatment, plasma treatment, chromic acid treatment (wet method), flame treatment, hot air treatment, ozone ‧ ultraviolet irradiation treatment, and the like. In addition, examples of the embossing method include a sand blast method, a solvent treatment method, and the like. These surface treatment methods are appropriately selected depending on the type of the plastic film. In general, the corona discharge treatment method is preferably used in terms of effects and operability. In addition, you can also set the bottom layer.

[Formation of hard coating]

Coating the hard coat layer on at least one surface of the transparent plastic film by a conventionally known method such as a bar coating method, a knife coating method, a roll coating method, a blade coating method, a slit die coating method, a gravure coating method, or the like. The material is formed into a coating film, and after drying, it is irradiated with an active energy ray to harden the coating film to form a hard coat layer.

Examples of the active energy ray include ultraviolet rays, electron beams, and the like. The ultraviolet rays are obtained by a high-pressure mercury lamp, an electrodeless lamp, a metal halide lamp, a xenon lamp, or the like, and the irradiation amount is usually 100 to 500 mJ/cm ² . On the other hand, the electron beam is obtained by an electron beam accelerator or the like, and the irradiation amount is usually 150 to 350 kV. . Among the active energy rays, ultraviolet rays are particularly suitable. Further, when an electron beam is used, a cured film can be obtained without adding a photopolymerization initiator.

The thickness of the hard coat layer thus formed is usually from about 3 to 15 μm, preferably from 3 to 10 μm, from the viewpoints of the particle diameter of the spherical organic fine particles and the prevention of warpage.

[Anti-glare hard coating film]

The antiglare hard coating film of the present invention thus obtained has the following optical properties.

(haze value)

The total haze value of the hard coat layer is 20% or less, and the value of "total haze value - internal haze value" (that is, external haze value) is -10 to +1%, preferably -5 to +1%. As long as the values of the total haze value and the "total haze value - internal haze value" are in the above range, fading and reduction in contrast can be reduced, and at the same time, high image sharpness and appropriate anti-glare property can be achieved.

Further, the haze value was measured in accordance with JIS K 7136, and the internal haze value and the total haze value were values measured according to the following methods.

<Measurement of internal fog value and total fog value>

The haze value of the antiglare hard coating film and the individual haze value of the transparent plastic film were measured in accordance with JIS K 7136.

The value of the haze value of the transparent plastic film alone is subtracted from the haze value of the above-mentioned antiglare hard coating film as the total haze value.

Next, a transparent adhesive sheet having an adhesive layer having a thickness of 20 μm on a transparent film having a thickness of 50 μm was attached to the hard coat layer side of the antiglare hard coating film to prepare a sample for internal haze value calculation. The haze value of the transparent adhesive sheet and the haze value of the sample for calculating the internal haze value were measured in accordance with JIS K 7136.

Further, the value obtained by subtracting the haze value of the transparent adhesive sheet and the haze value of the transparent plastic film from the haze value of the internal haze value calculation sample is used as the internal haze value of the hard coat layer of the antiglare hard coating film. .

Further, since the haze value of the transparent adhesive sheet is subtracted in the above calculation process and does not directly affect the internal haze value and the total haze value, it is not particularly limited, and from the viewpoint of improving the measurement accuracy, it is preferable to use the haze value insufficiently. 15%. Further, based on the same viewpoint, the total light transmittance of the transparent adhesive sheet is preferably 85% or more.

(60° specular gloss)

Using a gloss meter, the 60° specular gloss measured according to JIS K 7105 is usually 150 or less, preferably 80 to 150, more preferably 100 to 150.

In addition, the surface average roughness Ra of the hard coat layer of the anti-glare hard coating film of the present invention is usually about 0.02 to 0.30 μm, preferably 0.04 to 0.20 μm when measured in JIS B 0601-1994.

Further, the surface resistivity of the hard coat layer is preferably 10 ¹³ Ω/□ or less, more preferably 10 ¹² Ω/□ or less, and the antistatic property can be imparted.

(other functional layers)

In the anti-glare hard-coated film of the present invention, an antireflection layer such as a siloxane-based coating film or a fluorine-based coating film may be provided on the uppermost layer for the purpose of imparting antireflection properties and the like as necessary. At this time, the thickness of the antireflection layer is suitably about 0.05 to 1 μm. By providing the antireflection layer, it is possible to eliminate the reflection of a screen caused by reflection of sunlight, a fluorescent lamp, etc., and by suppressing the reflectance of the surface, the total light transmittance can be improved and the transparency can be improved. Further, by changing the type of the antireflection layer, the antistatic property can be improved.

(adhesive layer)

In the antiglare hard coating film of the present invention, an adhesive layer for bonding to an adherend such as a liquid crystal display body is formed on a surface opposite to the hard coat layer of the plastic film. As the binder constituting the binder layer, it is preferably used for optical applications such as an acrylic adhesive, a polyurethane adhesive, and an organic silicone adhesive. The thickness of the adhesive layer is usually in the range of 5 to 100 μm, preferably 10 to 60 μm.

Further, a release sheet may be provided on the adhesive layer as needed, and examples of the release sheet include a release agent such as an organic silicone resin coated on various plastic films such as polyethylene terephthalate or polypropylene. Peeling pieces, etc. The thickness of the release sheet is not particularly limited, but is usually about 20 to 150 μm.

The anti-glare hard coating film in which the adhesive layer is formed is suitably used as a member for imparting anti-glare properties, abrasion resistance, and the like to displays such as CRTs, LCDs, and PDPs, and is particularly suitable for being laminated as a polarizing plate in an LCD or the like. use.

[Polarizer]

The present invention also provides a polarizing plate formed by laminating the above-described antiglare hard coating film of the present invention onto a polarizing plate.

The liquid crystal cell in the LCD is generally configured such that two transparent electrode substrates on which the alignment layer is formed are disposed on the inner side of the alignment layer, and are formed by forming a predetermined gap through the spacer, sealing the periphery thereof, and sandwiching the gap. In the liquid crystal material, a polarizing plate is disposed on the outer surface of each of the two transparent electrode substrates through an adhesive layer.

Fig. 1 is a perspective view showing a configuration of an example of the above polarizing plate. As shown in the figure, the polarizing plate 10 is generally formed on both sides of a polyvinyl alcohol-based polarizing film 1, and is laminated with a triacetyl cellulose (TAC) film 2 and 2' to form a substrate having a three-layer structure. Further, an adhesive layer 3 for bonding to an optical member such as a liquid crystal cell is formed on one surface thereof, and then the release sheet 4 is bonded to the adhesive layer 3. Further, a surface protective film 5 is usually provided on the surface of the polarizing plate opposite to the adhesive layer 3.

The polarizing plate of the present invention is provided with the above-described hard coat layer of the present invention on one TAC film in the TAC films 2, 2' provided on both faces of the polarizing plate 1. When the adhesive layer 3, the release sheet 4, and the surface protective film 5 are provided on the polarizing plate, the hard coat layer of the present invention is provided particularly on the side of the TAC film 2' on the side of the surface protective film 5.

The method of producing the polarizing plate of the present invention can be carried out, for example, by the operation shown below.

In addition, FIG. 2 is a schematic cross-sectional view showing a configuration of an example of a polarizing plate of the present invention.

First, a transparent plastic film of a non-optical anisotropic film 12' such as a TAC film is used as a base material, and the hard coat layer 13 of the present invention is formed on one surface thereof to form an anti-glare hard coat film 14. Then, the TAC film 12 on which the hard coat layer 13 is not formed is laminated on one surface of the polarizer 11 and the anti-glare hard coat film 14 is laminated on the opposite surface, using the adhesive layers 15 and 15'. When the TAC film is used for the transparent plastic film, saponification treatment other than the above surface treatment may be performed in order to improve the adhesion at the time of laminating the adhesive.

Thereby, the polarizing plate 20 excellent in anti-glare performance and abrasion resistance is obtained. The polarizing plate 20 is also provided with the peelable surface protection film 5 shown in Fig. 1 on the surface on which the hard coat layer 13 is provided, or is provided on the opposite surface for bonding to an optical member such as a liquid crystal cell. Adhesive layer 16 or release sheet 17.

The polarizing plate of the present invention can be used as a light amount adjusting application typified by a liquid crystal cell use in an LCD, a use of a polarized interference application device, an optical defect detector, or the like.

[Examples]

Next, the present invention will be described in more detail by way of examples, but the invention is not limited by these examples.

Further, the average particle diameter and refractive index of the spherical organic fine particles, the refractive index of the cured product of the active energy ray-inductive composition, and the properties of the hard coating film were determined by the following methods.

<spherical organic particles> (1) Refractive index

The spherical organic fine particles of the measurement object were placed on a glass slide, and the refractive index standard solution was dropped on the fine particles, and then the cover glass was covered to prepare a sample. This sample was based on the B method of JIS K 7142, and the refractive index of the refractive index standard solution in which the outline of the fine particles was the most invisible was observed by a microscope as the refractive index of the fine particles.

<Active energy ray-sensitive composition> (2) Refractive index of the cured product

In each of the preparation examples, a coating agent formed of the active energy ray-sensitive composition (A), a photopolymerization initiator, and a diluent solvent was produced. In the same manner as in the Example, it was applied to a TAC film [manufactured by Fujifilm Co., Ltd., trade name "TAC80TD80ULH"), and cured by ultraviolet irradiation to obtain a hard coating film for refractive index measurement of the cured product. Based on the A method of JIS K 7142, the refractive index of the hard coat layer was determined using an Abbe refractometer manufactured by ATAGO Co., Ltd. as the refractive index of the cured product of the active energy ray-sensitive composition.

<hard coated film> (3) Total light transmittance

The total light transmittance of the antiglare hard coat film produced in the examples and the comparative examples was measured in accordance with JIS K 7361-1 using an atomizer "NDH-2000" manufactured by Nippon Denshoku Industries Co., Ltd.

(4) Internal haze value, total haze value and "total haze value - internal haze value" of the hard coating layer

The anti-glare hard-coated film produced in the examples and the comparative examples and the transparent plastic film as a constituent material of the film were measured according to JIS K 7136 using a haze meter "NDH-2000" manufactured by Nippon Denshoku Industries Co., Ltd. The individual fog value.

The haze value of the antiglare hard coating film obtained by the above measurement was subtracted from the haze value of the transparent plastic film to calculate the total haze value of the hard coat layer of the antiglare hard coating film.

Next, 2 parts by mass of an isocyanate crosslinking agent (manufactured by Toyo Ink Co., Ltd., trade name "BHS-8515") and 100 mass were added to 100 parts by mass of an acrylic adhesive [manufactured by Japan CARBIDE Co., Ltd., trade name "PE-121"]. A portion of toluene was used to make a binder solution.

Next, a binder solution was applied to a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., trade name "A4300") having a thickness of 50 μm as a transparent film so that the thickness of the adhesive layer after drying was 20 μm. Drying at 100 ° C for 3 minutes to produce a transparent adhesive sheet.

The produced transparent adhesive sheet was bonded to the hard coat side of the anti-glare hard-coated film as a sample for calculating the internal haze value. The various haze values of the transparent adhesive sheet and the internal haze value calculation sample were measured in accordance with JIS K 7136 in the same manner as described above.

Then, the haze value of the sample for calculating the internal haze value was subtracted from the haze value of the transparent adhesive sheet and the haze value of the transparent plastic film, and the internal haze value of the hard coat layer of the antiglare hard coating film was calculated.

Finally, the "total haze value - internal haze value" of the hard coat layer of the antiglare hard coating film was calculated by subtracting the internal haze value from the above total haze value.

(5) Evaluation of anti-glare

The hard coating film was bonded with an acrylic adhesive on an acrylic resin blackboard [manufactured by Mitsubishi Rayon Co., Ltd.], and the formed sample was visually observed under a fluorescent lamp, and the anti-glare property was evaluated based on the following criteria.

○: The fluorescent lamp is fully prevented from being reflected, and there is no fading.

×: Prevents the reflection of the fluorescent lamp from being insufficient, or prevents the fluorescent lamp from being reflected, but the fading is obvious and the visibility is poor.

(6) 60° specular gloss

The gloss meter "VG2000" manufactured by Nippon Denshoku Industries Co., Ltd. was used and measured in accordance with JIS K 7105.

(7) Image clarity

The imageability measuring instrument "ICM-10P" manufactured by Suga Test Machine Co., Ltd. was used in accordance with JIS K 7374. The total value of the five slits (slit width: 0.125 mm, 0.25 mm, 0.5 mm, 1 mm, and 2 mm) was recorded as image sharpness.

(8) Thickness of hard coating

An anti-glare hard coating film produced in the examples and the comparative examples, a TAC (triethyl fluorene-based cellulose) film and a PET (polyethylene terephthalate) which are transparent plastic films used in the production of the anti-glare hard coating film. The diester) film was each measured for thickness by a constant pressure thickness meter [manufactured by Nikon Corporation, trade name "MH-15M"], and the thickness of the hard coat layer was calculated by taking the difference.

Preparation Example 1 Coating Agent for Hard Coating 1

50 parts by mass of a hard coating agent containing an antistatic agent (a compound containing a quaternary ammonium base) as the (A) active energy ray-sensitive composition [manufactured by Nippon Kasei Co., Ltd., trade name "L80313", solid content concentration 70% by mass, propylene glycol monomethyl ether 30% by mass] and 35 parts by mass of a hard coating agent containing no antistatic agent [manufactured by Dairi Seiki Co., Ltd., trade name "SEIKA-BEAM EXF-01L (NS)" , the solid content concentration is 100% by mass, the active energy ray-curable compound containing the reactive monomer and the polyfunctional acrylate is 95% by mass, and the photopolymerization initiator is 5% by mass, and 4 parts by mass of the (B) spherical organic fine particles. Polystyrene-polymethyl methacrylate (PSt-PMMA) fine particles (manufactured by Sekisui Chemicals Co., Ltd., average particle diameter: 2.5 μm, refractive index: 1.555), and 90 parts by mass of toluene as a diluent solvent were uniformly mixed to produce a solid. The coating agent 1 for hard coat layer was about 41% by mass. Further, the cured product of the active energy ray-sensitive composition had a refractive index of 1.525.

Preparation Example 2 Coating Agent for Hard Coating 2

In addition to 4 parts by mass of polymethyl methacrylate (PMMA) fine particles as (B) spherical organic fine particles [manufactured by Kyowa Chemical Co., Ltd., average particle diameter 3 μm, refractive index 1.49], 90 parts by mass of propylene glycol as a diluent solvent A coating agent 2 for a hard coat layer having a solid content of about 41% by mass was prepared in the same manner as in Production Example 1 except for the monomethyl ether.

Preparation Example 3 Coating Agent for Hard Coating 3

A solid content of about 41% by mass was prepared in the same manner as in Preparation Example 1 except that 4 parts by mass of PMMA fine particles (manufactured by Sekisui Chemicals Co., Ltd., average particle diameter: 5 μm, refractive index: 1.49) were added in an amount of 4 parts by mass. The coating agent 3 for the hard coat layer.

Preparation Example 4 Coating Agent for Hard Coating 4

In addition to 4 parts by mass of polystyrene (PSt) fine particles as (B) spherical organic fine particles [manufactured by Kyowa Chemical Co., Ltd., average particle diameter: 1.3 μm, refractive index: 1.59], 36 parts by mass of methyl ethyl ketone and 54 as a diluent solvent A coating agent 4 for a hard coat layer having a solid content of about 41% by mass was prepared in the same manner as in Production Example 1 except that the propylene glycol monomethyl ether was used.

Preparation Example 5 Coating Agent for Hard Coating 5

A solid content of about 41 was prepared in the same manner as in Preparation Example 2, except that 4 parts by mass of PSt-PMMA fine particles (manufactured by Sekisui Chemicals Co., Ltd., average particle diameter: 2 μm, refractive index: 1.555) as a (B) spherical organic fine particle were added. % by mass of coating agent 5 for hard coat.

Preparation Example 6 Coating Agent for Hard Coating Layer 6

100 parts by mass of a hard coating agent containing an antistatic agent (a quaternary ammonium base-containing compound) as the (A) active energy ray-sensitive composition [manufactured by Nippon Kasei Co., Ltd., trade name "L80313", solid content concentration 70% by mass, propylene glycol monomethyl ether 30% by mass], 35 parts by mass of methyl ethyl ketone as a diluent solvent, and 35 parts by mass of propylene glycol monomethyl ether were uniformly mixed to prepare a coating agent 6 for a hard coat layer having a solid content of about 41% by mass.

Example 1

The coating agent 1 obtained in Preparation Example 1 was coated on a surface of a triacetyl cellulose (TAC) film (manufactured by Fujifilm Co., Ltd.) having a thickness of 80 μm by a Meyer bar so that the cured film thickness was about 5 μm. After drying in an oven at 70 ° C for 1 minute, ultraviolet rays of 300 mJ/cm ² were irradiated by a high pressure mercury lamp to produce an antiglare hard coating film.

The properties of the hard coating film are shown in Table 1.

Example 2

An anti-glare hard coating film was produced in the same manner as in Example 1 except that the coating agent 2 obtained in Preparation Example 2 was applied by a Meyer bar to have a cured film thickness of about 5 μm.

The properties of the hard coating film are shown in Table 1.

Example 3

An anti-glare hard coating film was produced in the same manner as in Example 1 except that the coating agent 3 obtained in Preparation Example 3 was applied by a Meyer bar to have a cured film thickness of about 5 μm.

The properties of the hard coating film are shown in Table 1.

Example 4

The coating agent 3 obtained in Preparation Example 3 was coated with a Meyer bar in addition to a polyethylene terephthalate (PET) film (manufactured by Toyobo Co., Ltd.) having a thickness of 188 μm so that the cured film thickness was about 5 μm. An anti-glare hard coating film was produced in the same manner as in Example 1.

The properties of the hard coating film are shown in Table 1.

Comparative example 1

An anti-glare hard coating film was produced in the same manner as in Example 1 except that the coating agent 4 obtained in Preparation Example 4 was applied by a Meyer bar to have a cured film thickness of about 4 μm.

The properties of the hard coating film are shown in Table 1.

Comparative example 2

An anti-glare hard coating film was produced in the same manner as in Example 4 except that the coating agent 4 obtained in Preparation Example 4 was applied by a Meyer bar to have a cured film thickness of about 4 μm.

The properties of the hard coating film are shown in Table 1.

Comparative example 3

An anti-glare hard coating film was produced in the same manner as in Example 1 except that the coating agent 5 obtained in Preparation Example 5 was applied by a Meyer bar to have a cured film thickness of about 5 μm.

The properties of the hard coating film are shown in Table 1.

Comparative example 4

An anti-glare hard coating film was produced in the same manner as in Example 1 except that the coating agent 6 obtained in Preparation Example 6 was applied by a Meyer bar to have a cured film thickness of about 5 μm.

The properties of the hard coating film are shown in Table 1.

[Note]

PSt-PMMA: polystyrene-polymethyl methacrylate particles

PMMA: Polymethyl methacrylate particles

PSt: polystyrene particles

PGM: propylene glycol monomethyl ether

MEK: methyl ethyl ketone

TAC: triethylene fluorene fiber film

PET: polyethylene terephthalate

Industrial applicability

The anti-glare hard coating film of the present invention has a hard coat layer containing spherical organic fine particles, and by reducing the total haze value of the hard coat layer and the "total haze value - internal haze value" to a predetermined value, fading and contrast can be reduced. Moreover, it has high image clarity and appropriate anti-glare properties, so it is suitable for use as a component for imparting anti-glare properties and wear resistance to displays such as CRTs, LCDs, and PDPs, and is particularly suitable as a polarizing plate for LCDs and the like. Suitable for use.

1. . . Polyvinyl alcohol polarizer

2. . . TAC film

2'. . . TAC film

3. . . Adhesive layer

4. . . Peeling piece

5. . . Surface protection film

10. . . Polarizer

11. . . Polarizer

12. . . TAC film

12’. . . TAC film

13. . . Hard coating

14. . . Anti-glare hard coating

15’. . . Adhesive layer

16. . . Adhesive layer

17. . . Peeling piece

20. . . Polarizer

Fig. 1 is a perspective view showing a configuration of an example of a polarizing plate.

Fig. 2 is a schematic cross-sectional view showing the structure of an example of a polarizing plate of the present invention.

11. . . Polarizer

12. . . TAC film

12’. . . TAC film

13. . . Hard coating

14. . . Anti-glare hard coating

15’. . . Adhesive layer

16. . . Adhesive layer

17. . . Peeling piece

20. . . Polarizer

Claims (5)

An anti-glare hard coating film characterized in that a surface of a transparent plastic film has a hard coat layer formed using a hard coat forming material, and the hard coat layer forming material contains (A) an active energy ray-sensitive composition, B) spherical organic fine particles and a compound containing a quaternary ammonium base, and the total haze value of the hard coat layer is 20% or less, and the value of "total haze value - internal haze value" is in the range of -10 to +1%, The surface resistivity of the hard coat layer is 10 ¹³ Ω/□ or less. An anti-glare hard coating film according to the first aspect of the invention, wherein the spherical organic fine particles of the component (B) have an average particle diameter of 1 to 10 μm. An anti-glare hard coating film according to claim 1 or 2, wherein the specular gloss of 60° is 150 or less. An anti-glare hard coating film according to claim 1 or 2, wherein the surface of the hard coat layer has an arithmetic mean roughness Ra of 0.02 to 0.30 μm. A polarizing plate which is formed by laminating a surface on the opposite side of the hard coat layer forming surface of the antiglare hard coating film according to any one of claims 1 to 4 toward the polarizer.