KR101719819B1 - An anti-glare hard coat film and a polarizing plate using the same - Google Patents

Abstract

The present invention can change the inner haze value without largely changing the outer haze value, and it is easy to adjust the outer / inner haze value at the time of mass production of the film, and the desired 60 degree mirror polish degree and anti- Which is capable of obtaining a light-scattering hard coat film. As a means for solving the problem, there is proposed a method in which a surface of a transparent plastic film is coated with a coating liquid containing a mixture of (A) a polyfunctional (meth) acrylate monomer and / or a (meth) acrylate based prepolymer, and (b) (B) specific spherical organic fine particles having an average particle diameter of 1 to 10 占 퐉, (C) specific spherical silicon-containing fine particles having an average particle diameter of 0.5 to 10 占 퐉, and (D) (B) and (C), wherein the thickness of the hard coat layer is larger than that of each of the (B) component and the (C) component. The hard coat layer is formed by using a hard coat layer- .

Description

(AN ANTI-GLARE HARD COAT FILM AND A POLARIZING PLATE USING THE SAME)

The present invention relates to a light-scattering hard coat film and a polarizing plate using the same. More specifically, the present invention relates to an antireflective hard-coat film having a scratch resistance, in which a hard coat layer containing spherical organic fine particles and spherical silicon-containing fine particles is formed, and which can change the internal haze So that it is possible to easily adjust the outer / inner haze value when the film is mass-produced, to obtain a desired 60 ° specular gloss and light-shielding property without deteriorating the contrast, and a light- To a polarizing plate using a film.

In a display such as a cathode ray tube (CRT), a liquid crystal display (LCD), or a plasma display (PDP), light may be incident on the screen from the outside and the light may be reflected to make the display image invisible. It has become increasingly important to solve the above problem. One of means for solving this problem is to use a member having a flash-resistant hard coat layer.

In recent years, it has been required in the retardation film of the present invention to have an internal haze derived from the light diffusing property inside the film in order to reduce the glare in addition to the external haze due to the surface unevenness for the purpose of imparting the conventional anti- have.

This internal haze value can be exerted by containing fine particles having a refractive index difference from the binder resin in the hard coat layer. However, in the case of producing a light-scattering film using only one kind of fine particles having a refractive index difference from the binder resin, the fine particles must contribute to both of the outer / inner haze. Therefore, there has been a problem that it is difficult to adjust the outer / inner haze value at the time of production because both the outer and inner haze values of the anti-glare film vary depending on the type and amount of the filler.

In order to solve this problem, the inventors of the present invention have discovered a technique of adding a certain amount of one kind of organic fine particles (the internal haze is fixed) and adjusting the external haze value by the amount of the dispersing agent (surfactant) (Japanese Patent Application No. 2008-087295).

On the other hand, an antiglare film on which an antiglare layer composed of resin beads having a refractive index of 1.40 to 1.60 and an ionizing radiation curable composition is formed on a transparent substrate is proposed. For example, in Patent Document 1, an anti-glare film using an organic filler having a particle diameter equal to or greater than the thickness of a coating film (coating film) has been proposed in order to form irregularities that exhibit anti-glare properties. However, There is a problem that the haze value increases and the transmission sharpness decreases. In order to solve this problem, in Patent Document 2, by adding an organic filler having a particle diameter equal to or smaller than the film thickness of the coating film to reduce the addition amount of the organic filler having a particle diameter equal to or larger than the film thickness of the unevenness- Is proposed.

However, in reality, even if optical properties can be balanced by the above-described method, unevenness of the particle size of the used fine particles causes portions where there are no irregularities to appear, and the anti-scattering property can not be obtained on the whole surface. In addition, there is a problem that stable productivity is deteriorated due to a large fluctuation of the external haze value due to the film thickness. Also, in these systems, the film thickness is determined by the size of the fine particles, and it becomes difficult to adjust the physical properties in which the performance is changed by the film thickness such as the surface hardness.

Japanese Patent Application Laid-Open No. 6-18706 Japanese Patent No. 3515401

Disclosure of the Invention The present invention has been accomplished under such circumstances, and it is an object of the present invention to provide a light-scattering hard coat film in which a hard coat layer having scratch resistance is formed on the surface of a transparent plastic film and can change the internal haze value without greatly changing the external haze value, It is possible to easily adjust the outer / inner haze value at the time of mass production, to provide a desired hardness of 60 °, and to provide a desired polarizing plate using the hard-coat film of the present invention And the like.

The inventors of the present invention have conducted intensive studies in order to achieve the above object, and as a result, the following insights have been obtained.

As the hard coat layer, a hard coat layer forming material containing a specific spherical organic fine particle, a specific spherical silicon fine particle, and a surfactant having an average particle diameter in a desired range, and an active energy ray- And the thickness of the hard coat layer is made larger than the average particle diameter of each of the spherical organic fine particles and the spherical silicon fine particles to obtain a flash-resistant hard coat film which can be suitable for the above purpose Respectively.

Further, in the present anti-glare hard coat film, the difference between the refractive index of the cured product of the active energy beam-sensitive composition, the refractive index of the spherical organic fine particles and the refractive index of the spherical silicon-based fine particles is defined as a specific range , And that the hard coat layer forming material further contains a surfactant, so that it can be easily adapted to the purpose.

The present invention has been completed based on such insights.

That is,

(1) A method for producing a transparent plastic film, comprising the steps of: (1) coating a surface of a transparent plastic film with a coating liquid containing (A) a polyfunctional (meth) acrylate monomer and / or a (meth) acrylate based prepolymer, (B) at least one spherical organic resin selected from an acrylic resin having an average particle diameter of 1 to 10 占 퐉, an acryl-styrene resin, a melamine resin, a polycarbonate resin, a styrene resin and a vinyl chloride resin (C) at least one spherical silicon-based fine particle selected from a silicone resin having an average particle diameter of 0.5 to 10 탆, hollow silica and porous silica, and (D) a surfactant Wherein the hard coat layer has a hard coat layer formed using a hard coat layer forming material and the thickness of the hard coat layer is larger than the average particle diameter of each of the (B) component and the (C) component. ,

(2) The light-scattering hard coat film according to (1), wherein the silica-based fine particles (b) are fine silica particles having a group containing a (meth) acryloyl group as a surface functional group,

(1) or (2), wherein the refractive index difference between the cured product of the component (A) and the component (B) is less than 0.02 and the refractive index difference between the cured product of the component (A) The hard coat film of the present invention,

(4) A polarizing plate comprising a polarizing element bonded to a surface opposite to the hard coat layer-forming surface of the light-scattering hard coat film according to any one of claims 1 to 3.

According to the present invention, there is provided a light-scattering hard coat film having scratch resistance, in which a hard coat layer containing spherical organic fine particles and spherical silicon fine particles is formed, can change the internal haze without significantly changing the external haze value, A hard-coatable hard-coat film capable of easily adjusting outer / inner haze values at the time of mass production of a film, achieving a desired 60-degree specular gloss and antistatic property without deteriorating the contrast, and a polarizing plate Can be provided.

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

(A) a polyfunctional (meth) acrylate-based monomer and / or a (meth) acrylate-based prepolymer; and (b) a silica-based fine particle (B) Specific spherical organic fine particles shown below having an average particle diameter of 1 to 10 占 퐉, (C) Specific spherical silicon-based fine particles shown below having an average particle diameter of 0.5 to 10 占 퐉 , And (D) a hard coat layer formed by using a hard coat layer forming material containing a surfactant, and the thickness of the hard coat layer is larger than the average particle diameter of each of the components (B) and (C) It is characterized by large.

[Hard coat layer forming material]

The hard coat layer-forming material in the present invention contains (A) an active energy ray-sensitive composition, (B) spherical organic fine particles, (C) spherical silicon-based fine particles, and (D) a surfactant.

((A) an active energy ray-sensitive composition)

The active energy ray-sensitive composition used as the component (A) in the hard coat layer-forming material preferably contains (a) a multifunctional (meth) acrylate monomer and / or a (meth) acrylate Based prepolymer and (b) silica-based fine particles are contained as essential components.

In the present invention, the active energy ray refers to those having energy in the electromagnetic wave or charged particle beam, that is, ultraviolet rays, electron beams, and the like.

< (a) Active energy ray curable compound >

In the present invention, as the active energy ray curable compound (a), a multifunctional (meth) acrylate monomer and / or a (meth) acrylate based prepolymer is used.

Examples of the polyfunctional (meth) acrylate monomer include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) Acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, (Meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, isocyanurate di (meth) acrylate, , Propionic acid-modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide-modified trimethylolpropane tri (meth) (Meth) acrylate such as tris (acryloxyethyl) isocyanurate, propionic acid modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (metha) acrylate and caprolactone modified dipentaerythritol hexa (Meth) acrylate. 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 acrylate-based, epoxyacrylate-based, urethane acrylate-based, polyol acrylate-based and the like. Examples of the polyester acrylate-based prepolymer include a polyester oligomer obtained by esterification of a hydroxyl group of a polyester oligomer having a hydroxyl group at the end of its ends with (meth) acrylic acid obtained by condensation of a polyhydric carboxylic acid and a polyhydric alcohol, Can be obtained by esterifying the hydroxyl group at the terminal of the oligomer obtained by adding an alkylene oxide to (meth) acrylic acid.

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

< (b) Silica-based fine particles >

In the present invention, as the silica-based fine particles (b), fine silica particles having colloidal silica fine particles and / or surface functional groups can be used.

The colloidal silica fine particles have an average particle diameter of about 1 to 400 nm. As the silica fine particles having a surface functional group, for example, silica fine particles having a group containing a (meth) acryloyl group as a surface functional group Silica fine particles are sometimes referred to as silica fine particles).

The reactive silica fine particles can be obtained, for example, by reacting a silanol group on the surface of fine silica particles having an average particle size of about 0.005 to 1 탆 with a polymerizable unsaturated group-containing organic compound having a functional group capable of reacting with the silanol group have. The polymerizable unsaturated group includes, for example, a radical polymerizable (meth) acryloyl group.

Examples of the polymerizable unsaturated group-containing organic compound having a functional group reactive with the silanol group include acrylic acid, acrylic chloride, 2-hydroxyethyl acrylate, acryloyloxypropyltrimethoxysilane, and methacrylic acid derivatives corresponding to the acrylic acid derivatives thereof. These acrylic acid derivatives and methacrylic acid derivatives may be used alone or in combination of two or more.

The thus obtained fine silica particles to which the polymerizable unsaturated group-containing organic compound is bonded are crosslinked and cured by irradiation with an active energy ray as an active energy ray curing component.

These reactive silica fine particles have the effect of improving the scratch resistance of the obtained hard coat film.

Examples of the active energy ray-sensitive composition (A) containing a compound obtained by bonding an organic compound having a polymerizable unsaturated group to such silica fine particles include, for example, those available under the trade names "OPSTAR Z7530" "Obstar Z7524" and "Observer TU4086" are commercially available.

In the present invention, the content of the silica-based fine particles in the component (b) is usually about 5 to 90% by mass, and preferably 10 to 70% by mass, based on the solid content of the active energy ray-

The average particle diameter of the silica particles in the silica-based fine particles of the component (b) can be measured by a laser diffraction / scattering method. In this method, an average particle diameter is measured by a change in the intensity of light diffracted and scattered when laser light is applied to a liquid in which particles are dispersed.

((B) spherical organic fine particles)

Examples of the spherical organic fine particles used as the component (B) in the hard coat layer-forming material in the present invention include acrylic resins, acrylic-styrene resins, melamine resins, Based resin, a polycarbonate-based resin, a styrene-based resin, and a vinyl chloride-based resin. On the other hand, when the average particle diameter of the spherical organic fine particles is less than 1 탆, the occurrence of the scattering property becomes insufficient. On the other hand, when the average particle diameter exceeds 10 탆, the particle diameter of the spherical organic fine particles and the thickness of the hard coat layer The amount of floating of the spherical organic fine particles from the surface of the transparent plastic film is so small that the spherical organic fine particles are strongly influenced by the unevenness of the particle diameter or the dispersibility of the spherical organic fine particles at the time of coating becomes insufficient, Unevenness may occur in the unevenness of the coat layer. The preferred average particle diameter is 2 to 8 占 퐉. The average particle diameter is a measurement value based on the Coulter counter method. It is preferable that the particle size distribution has a weight fraction of 70% or more within a range of 占 2 占 퐉 of the average particle size measured by the Coulter counter method.

In the present invention, the spherical organic fine particles of the component (B) may be used alone, or two or more kinds may be used in combination. In addition, from the viewpoint of the antiglare performance, Is preferably 0.5 to 30 parts by mass, more preferably 1 to 20 parts by mass, and particularly preferably 3 to 15 parts by mass, based on 100 parts by mass of the solid content of the active energy beam-sensitive composition.

In the present invention, the cured product of the active energy beam-sensitive composition as the component (A) and the spherical organic fine particles as the component (B) are preferably less than 0.02 from the viewpoint of suppressing an increase in the internal haze , And more preferably 0.01 or less. These spherical organic fine particles are mainly used for adjustment of external haze value. The refractive index of the spherical organic fine particles is a measurement value according to the method B of JIS K 7142. The refractive index of the cured product of the active energy ray-sensitive composition is a measurement value according to Method A of JIS K 7142.

((C) spherical silicon-based fine particles)

In the hard coat layer-forming material of the present invention, the spherical silicon-based fine particles to be used as the component (C) are preferably selected from silicone resins, hollow silica and porous silica having an average particle diameter of 0.5 to 10 탆 At least one of them may be mentioned. When the average particle diameter of the spherical silicon-based fine particles is less than 0.5 mu m, the effect of acting on the inner haze is insufficient, while when it exceeds 10 mu m, the difference from the film thickness of the hard coat layer formed becomes small, The external haze value may be influenced by unevenness of the particle size of the fine particles. The average particle diameter is preferably 1 to 8 탆, particularly preferably 2 to 6 탆. The average particle diameter is a measurement value based on the Coulter counter method. It is preferable that the particle size distribution has a weight fraction of not less than 70% in the range of not more than +/- 2 mu m of the average particle size measured by the Coulter counter method.

In the present invention, the spherical silicon-containing fine particles of component (C) may be used singly or in combination of two or more kinds. In addition, from the viewpoint of the anti-glare performance, Is preferably from 0.5 to 30 parts by mass, more preferably from 1 to 20 parts by mass, and particularly preferably from 2 to 15 parts by mass, based on 100 parts by mass of the solid content of the active energy beam-sensitive composition as the component (A).

In the present invention, the cured product of the active energy beam-sensitive composition as the component (A) and the spherical silicon-based fine particles as the component (C) described above preferably have a refractive index difference of 0.02 to 0.2 , And more preferably 0.04 to 0.1. If the refractive index difference is less than 0.02, the effect on the internal haze value may be insufficient. If the refractive index difference is more than 0.2, there is a fear that the transmission sharpness and the like are adversely affected. The refractive index of the spherical silicon-based fine particles is a measurement value according to the method B of JIS K 7142.

((D) a surfactant)

In the hard coat layer-forming material of the present invention, a surfactant is used as the component (D). This surfactant suppresses the sedimentation of the spherical organic fine particles in the hard coat layer whose film thickness is larger than the average particle diameter of the spherical organic fine particles (C), and a large number of such fine particles are present in the vicinity of the surface of the hard coat layer , And has an action to improve the anti-glare performance, and there is no particular limitation on its kind.

Examples of such a surfactant include those having a polar group derived from an N, N-dialkylamino group having 1 to 8 carbon atoms in the alkyl group in the molecule. From the viewpoint of availability, it is particularly preferable to have a polar group derived from an N, N-dialkylaminoalkanol having 2 to 6 carbon atoms.

Specific examples of the N, N-dialkylamino alkanol include N, N-dimethylamino ethanol, N, N-diethylamino ethanol, N, N-dipropylamino ethanol, N, N-dipentylaminoethanol, N, N-dihexylaminoethanol and the like, and compounds obtained by replacing the ethanol moiety in these compounds with propanol or butanol. The two alkyl groups of the dialkyl moiety may be the same or different.

Examples of the surfactant having a polar group derived from an N, N-dialkylaminoalkanol include N, N-dialkylaminoalcohol-modified polyoxyalkylene glycols.

In the present invention, the surfactant of component (D) may be used singly or in combination of two or more kinds. The blending amount is preferably in the range of from 100 parts by mass to 100 parts by mass of the solid content of the active energy ray-sensitive composition as the above-mentioned component (A) from the viewpoint of balancing of the hard coat layer resistance to scattering, scratch resistance, Is 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass.

In the present invention, by containing the surfactant (D) in the hard coat layer-forming material, the lipophilic portion of the surfactant (B) is adsorbed on the surface of the spherical organic fine particles, and the hydrophilic portion of the adsorbed surfactant ) Spherical organic fine particles are hydrophilized, and (B) the spherical organic fine particles (B) are floated (surfaced) on the surface in the process of forming a hard coat layer comprising a lipophilic active energy ray- ). Therefore, by exerting a surfactant (D) on the spherical organic fine particles (B), the external haze can be mainly expressed. On the other hand, (C) the spherical silicon-based fine particles are adsorbed on the hydrophilic part of the surfactant (D) because they have a silanol group on the surface, and (D) ) Is believed to inhibit the surface of the spherical silicon-based fine particles from lipidation in the process of forming a hard coat layer containing the same lipophilic active energy ray-sensitive composition as the main component. Therefore, (C) the spherical silicon-based fine particles can mainly express only the internal haze by acting with (D) a surfactant.

(Photopolymerization initiator)

The hard coat layer forming material in the present invention may contain a photopolymerization initiator as desired. Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2 , 2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenyl Methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 4- (2-hydroxyethoxy) phenyl- ) Ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methyl anthraquinone, 2-ethyl anthraquinone, 2- Aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethylketal, acetophenone Dimethyl ketal, p-dimethylamino benzoic acid And the like.

These compounds may be used alone or in combination of two or more. The compounding amount is selected in the range of usually 0.2 to 10 parts by mass with respect to 100 parts by mass of the total active energy ray-curable compound. Here, the total active energy ray curable compound (b), when used as the silica-based fine particles, contains the reactive silica fine particles.

(Preparation of hard coat layer forming material)

The hardcoat layer-forming material used in the present invention may contain, if necessary, an active energy ray-sensitive composition of component (A), spherical organic fine particles of component (B), spherical A silicon-based fine particle, a surfactant of component (D), a photopolymerization initiator to be used in accordance with a desired state, and further various additives such as antioxidants, ultraviolet absorbers, silane coupling agents, light stabilizers, leveling agents, defoaming agents, And then dissolving or dispersing them in a predetermined ratio.

Examples of the solvent include aliphatic hydrocarbons such as hexane and heptane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and ethylene chloride, alcohols such as methanol, ethanol, propanol and butanol, acetone, , Ketones such as 2-pentanone, isophorone and cyclohexanone, esters such as ethyl acetate and butyl acetate, and cellosolve solvents such as ethyl cellosolve.

The concentration and viscosity of the hard coat layer-forming material prepared in this manner are not particularly limited and can be suitably selected in accordance with the circumstances as long as they can be coated.

[Transparent plastic film]

In the antiglare hard coat film of the present invention, a hard coat layer is formed on at least one side of the transparent plastic film by using the hard coat layer forming material prepared as described above.

The above-mentioned transparent plastic film is not particularly limited, and can be suitably selected from among plastic films known as a base material of a conventional optical hard coat film. Examples of such plastic films include polyester films such as polyethylene terephthalate (sometimes referred to as &quot; PET &quot;), polybutylene terephthalate and polyethylene naphthalate, polyethylene films, polypropylene films, A cellulose acetate film, a cellulose film, a triacetylcellulose film (sometimes referred to as a &quot; TAC film &quot;), an acetylcellulose butylate film, a polyvinyl chloride film, a polyvinylidene chloride film, a polyvinyl alcohol film, an ethylene- A polyimide film, a fluororesin film, a polyamide film, an acrylic resin film, a norbornene-based film, a polyimide film, a polycarbonate film, a polymethylpentene film, a polysulfone film, a polyetheretherketone film, a polyether sulfone film, Plastics such as resin films and cycloolefin resin films It may include ticks film.

In addition, when the light-scattering hard coat film of the present invention is used for a polarizing plate protective film, a TAC film is more preferable as a transparent plastic film for reasons such as excellent optical isotropy.

These plastic films may be either transparent or semitransparent, and may be colored or non-colored, and may be appropriately selected depending on the application. For example, when it is used for protection of a liquid crystal display, a colorless transparent film is very suitable.

The thickness of these plastic films is not particularly limited and may be appropriately selected according to circumstances, but is usually in the range of 15 to 300 占 퐉, preferably 30 to 200 占 퐉. The plastic film can be subjected to surface treatment on one side or both sides by an oxidation method, a concavo-convex method or the like, if desired, for the purpose of improving the adhesion with the layer formed on the surface. Examples of the oxidation method include a corona discharge treatment, a plasma treatment, a chromic acid treatment (wet), a flame treatment, a hot air treatment, an ozone / ultraviolet ray irradiation treatment and the like. Examples of the irregularity include sandblasting, And a solvent treatment method. These surface treatment methods are appropriately selected depending on the kind of the plastic film, but generally, the corona discharge treatment method is preferably used in view of effects and operability. In addition, a primer layer may be formed.

[Formation of hard coat layer]

The hard coat layer forming material is applied to 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 die coating method, a gravure coating method, A hard coat layer is formed by applying a coating film to form a coating film, drying the coating film, and irradiating it with an active energy ray to cure the coating film.

Examples of the active energy ray include ultraviolet rays and electron rays. The ultraviolet rays are obtained by a high-pressure mercury lamp, an electrodeless lamp, a metal halide lamp, a xenon lamp and the like, and the irradiation amount is usually 100 to 50 O mJ / cm 2 while the electron beam is obtained by an electron beam accelerator or the like, 150 to 350 kV. Of these active energy rays, ultraviolet rays are particularly suitable. When an electron beam is used, a cured product can be obtained without adding a photopolymerization initiator.

The thickness of the hard coat layer thus formed needs to be larger than the average particle diameter of each of the spherical organic fine particles of component (B) and the spherical silicon-based fine particles of component (C) used in the present invention, The lower limit is about 3 mu m, and the upper limit is about 20 mu m from the viewpoint of preventing the hard coat film from curling due to curing shrinkage of the hard coat layer. The preferred thickness is in the range of 5 to 15 mu m.

[Bang-hyeong hard coat film]

(Optical characteristics)

The optical characteristics of the thus-formed anti-glare hard coat film of the present invention may differ depending on the type thereof.

In the case of the high contrast type, the internal haze value is usually 0 to 10%. Since high contrast can be achieved even if the inner haze value is in this range, even if glare occurs, it can be sufficiently applied depending on the kind of display (design idea). When the internal haze value exceeds 10%, high contrast can not be obtained (general-purpose type). In the case of the general-purpose type, the internal haze value is usually 5 to 40%. When the internal haze value is less than 5%, the performance for suppressing glare is insufficient, and when it exceeds 40%, the visibility deteriorates. The preferable haze value of the general-purpose type of the light-scattering hard coat film is usually 10 to 30%, and preferably 15 to 25%.

The external haze value is preferably 20% or less from the viewpoint of visibility of both the high contrast type and the general type, and preferably 1% or more from the viewpoint of the dispersibility. Also, the internal haze value represents a haze due to only internal light scattering, and the external haze value represents a haze value caused only by the light scattering due to the unevenness of the surface, and the total haze value represents the total of the internal haze value and the external haze value. The total haze value is calculated by subtracting the haze value in accordance with JIS K 7136 of a transparent plastic film as a component of the light-scattering hard coat film from the haze value according to JIS K 7136 of the light- Value.

Hereinafter, a method of calculating the internal haze value, the external haze value, and the total haze value will be described.

<Calculation of Internal Haze Value, External Haze Value, and Total Haze Value of Hard Coat Layer>

First, in accordance with JIS K 7136, the haze value of the light-scattering hard-coat film of the present invention and the haze value of the transparent plastic film as a whole are measured.

The value obtained by subtracting the haze value of the transparent plastic film from the haze value of the non-reflective hard coat film is taken as the total haze value.

Next, a transparent pressure-sensitive adhesive sheet having a thickness of 20 占 퐉 was stuck to the hard coat layer side of the light-scattering hard coat film and used as a sample for calculating the internal haze value. The haze value of the transparent pressure-sensitive adhesive sheet and the haze value of the sample for calculating the internal haze value are measured according to JIS K7136.

The value obtained by subtracting the haze value of the transparent pressure sensitive adhesive sheet and the haze value of the transparent plastic film alone from the haze value of the sample for calculating the internal haze value is defined as the internal haze value of the hard coat layer of the optical film.

Finally, a value obtained by subtracting the internal haze value from the total haze value is defined as an external haze value.

Further, since the haze value of the above-mentioned transparent pressure sensitive adhesive sheet is not affected by the internal haze value, the external haze value and the total haze value, as it is subtracted in the calculation process as described above, there is no particular limitation, It is preferable to use a haze value of less than 5%.

In addition, it is preferable that the 60 ° mirror surface gloss is 20 to 130 in both the high-contrast type and the general-purpose type. 60 ° When the mirror polish degree exceeds 130, the surface gloss is large (the reflection of light is large), which adversely affects the antireflection property. 60 deg. When the mirror gloss (gross) is less than 20, fading occurs well. Further, the total light transmittance of the light-scattering hard coat film is preferably 88% or more, and more preferably 90% or more. When the total light transmittance is less than 88%, transparency may be insufficient.

The 60 占 specular glossiness is a measurement value according to JIS K 7105, and the total light transmittance is a measurement value according to JIS K 7136.

(effect)

The hard coat film of the present invention has a hard coat layer containing spherical organic fine particles and spherical silicon fine particles and has an antiscratching property and is capable of changing the internal haze value without significantly changing the external haze value So that adjustment of the outer / inner haze value at the time of mass production of the film is easy, and the desired 60 占 specular gloss and anti-scattering property can be obtained without deteriorating the contrast.

(Other function layer)

In the antiglare hard coat film of the present invention, an antireflection layer, for example, a siloxane coating film, a fluorine coating film, or the like can be formed for the purpose of imparting antireflection property to the uppermost layer, if necessary. In this case, the thickness of the antireflection layer is preferably about 0.05 to 1 mu m. By forming the antireflection layer, the screen reflection caused by the reflection by sunlight, fluorescent lamp or the like is eliminated, and the reflectance of the surface is suppressed, whereby the total light transmittance is increased and the transparency is improved. Further, depending on the kind of the antireflection layer, the antistatic property can be improved.

(Pressure-sensitive adhesive layer)

In the antiglare hard coat film of the present invention, a pressure-sensitive adhesive layer for adhering to an adherend such as a liquid crystal display can be formed on the side of the plastic film opposite to the hard coat layer. As the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer, for example, acrylic pressure-sensitive adhesives, urethane pressure-sensitive adhesives and silicone pressure-sensitive adhesives, which are suitable for optical applications, are preferably used. The thickness of the pressure-sensitive adhesive layer is usually 5 to 100 占 퐉, preferably 10 to 60 占 퐉.

Further, a release sheet can be formed on the pressure-sensitive adhesive layer, if necessary. Examples of the peeling sheet include those obtained by applying a releasing agent such as a silicone resin to various plastic films such as polyethylene terephthalate and polypropylene. The thickness of the release sheet is not particularly limited, but is usually about 20 to 150 mu m.

The light-scattering hard-coat film having such a pressure-sensitive adhesive layer is suitably used as a member for imparting an anti-glazing performance or scratch-resistant performance to a display such as a CRT, LCD, or PDP, For example.

[Polarizer]

The present invention also provides a polarizing plate formed by bonding the above-mentioned hard-coatable film of the present invention to a polarizer.

In a liquid crystal cell in an LCD, two transparent electrode substrates, on which an alignment layer is formed, are arranged in such a manner as to have a predetermined gap therebetween by using a spacer with the alignment layer as an inner side, And a polarizer is disposed on the outer surface of the two transparent electrode substrates via a pressure-sensitive adhesive layer.

1 is a perspective view showing an example of the structure of the polarizing plate. As shown in this figure, the polarizing plate 10 is generally composed of a polyvinyl alcohol-based polarizer 1 and a polarizing plate 2 having a triacetyl cellulose (TAC) film 2 and a polarizing plate 3 ' Sensitive adhesive layer 3 for adhering to an optical component such as a liquid crystal cell is formed on the surface of the adhesive layer 3 and a release sheet 4 is adhered to the pressure sensitive adhesive layer 3 have. On the surface of the polarizing plate opposite to the pressure-sensitive adhesive layer 3, a surface protective film 5 is usually formed.

The polarizing plate of the present invention is one in which a hard coat layer according to the present invention is formed on one of the TAC films 2 and 2 'formed on both sides of the polarizer 1. In the case where the pressure sensitive adhesive layer 3, the release sheet 4 and the surface protective film 5 are formed on the polarizing plate, the hard coat of the present invention, particularly the side of the TAC film 2 ' Layer is formed.

As a method for producing the polarizing plate of the present invention, for example, the following operations can be carried out.

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

First, a hard coat layer 13 according to the present invention is formed on one side of a transparent plastic film of a substrate using a film 12 'having no optically anisotropy such as a TAC film, and a light-shielding hard coat film 14 ). Next, the TAC film 12 on which the hard coat layer 13 is not formed on one side of the polarizer 11 is laminated on the opposite side to the above-mentioned flash-resistant hard coat film 14 with the adhesive layers 15 and 15 ' ). In the case of using a TAC film for a transparent plastic film, saponification treatment and the like can be carried out in addition to the above-mentioned surface treatment in order to improve adhesion by lamination with an adhesive.

Thus, the polarizing plate 20 having excellent anti-glare performance and scratch-resistant performance can be obtained. The polarizing plate 20 may also be provided on the surface of the hard coat layer 13 on which the peelable surface protective film 5 shown in Fig. 1 or an optical component such as a liquid crystal cell The pressure-sensitive adhesive layer 16 or the release sheet 17 may be formed.

The polarizing plate of the present invention can be used for a liquid crystal cell in an LCD, a light amount adjusting device, a polarization interference applying device, an optical defect detector, and the like.

<Examples>

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

The average particle diameter and refractive index of the organic fine particles and silicon-containing fine particles, the refractive index of the cured product of the active energy ray-sensitive composition and the performance of the hard coat film were determined by the following methods.

&Lt; Spherical organic fine particles and spherical silicon-based fine particles >

(1) average particle diameter

The measurement is carried out at 25 캜 by a Coulter counter method using a dispersion of 0.5% ion-exchanged water using a Coulter counter (product name: "Multisizer 3", manufactured by Beckman Coulter).

(2) Refractive index

The specimen was placed on a slide glass, the refractive index standard solution was dropped onto the specimen, and the specimen was covered with the cover glass. The sample is observed under a microscope in accordance with the method B of JIS K 7142, and the refractive index of the standard refractive index standard liquid in which the outline of the microparticles is most invisible is defined as the refractive index of the microparticle.

<Active Energy Line Sensing Composition>

(3) The refractive index of the cured product

In each preparation example, a coating agent comprising an active energy ray-sensitive composition (A), a photopolymerization initiator and a diluting solvent is prepared. This was applied to a TAC film (product name: "TAC80TD80ULH", product of Fuji Film Co., Ltd.) in the same manner as in Example to obtain a hard coat film for measuring the refractive index of a cured product. Based on the method A of JIS K 7142, the refractive index of the hard coat layer was determined using Abbe Refractometer manufactured by Atago Co., Ltd., and the refractive index was determined as the refractive index of the cured product of the active energy beam-sensitive composition.

<Hard Coat Film>

(4) Total light transmittance

Using a haze meter "NDH-2000" manufactured by Nippon Denshoku Kogyo Co., Ltd., the total light transmittance was measured for the non-light-sensitive hard coat film prepared in Examples and Comparative Examples in accordance with JIS K 7136.

(5) Internal haze value, external haze value, and total haze value of the hard coat layer

(Manufactured by Nippon Denshoku Chemical Co., Ltd.) using a haze meter &quot; NDH-2000 &quot; in accordance with JIS K 7136, a light-scattering hard coat film prepared in Examples and Comparative Examples, and a transparent plastic film film The haze value is measured.

The haze value of the transparent plastic film is subtracted from the haze value of the non-reflective hard coat film obtained by the above measurement to calculate the total haze value of the hard coat layer of the non-reflective hard coat film.

Next, 2 parts by mass of an isocyanato crosslinking agent (product of Toyo Ink Company, trade name: BHS-8515) and 100 parts by mass of toluene were added to 100 parts by mass of an acrylic pressure-sensitive adhesive (product of Nippon- To prepare a pressure sensitive adhesive solution. A pressure-sensitive adhesive sheet was prepared by applying a pressure-sensitive adhesive solution to a polyethylene terephthalate film having a thickness of 50 占 퐉 (trade name "A4300" manufactured by Toyobo Co., Ltd.) so that the thickness after drying was 20 占 퐉 and drying at 100 占 폚 for 3 minutes.

The prepared transparent pressure-sensitive adhesive sheet was stuck to the hard coat layer side of the light-shielding hard coat film and used as a sample for calculating the internal haze value. The haze value of each of the transparent pressure-sensitive adhesive sheet and the sample for calculating the internal haze value is measured in accordance with JIS K 7136 as described above.

Then, the haze value of the transparent pressure sensitive adhesive sheet and the haze value of the transparent plastic film are subtracted from the haze value of the sample for calculating the internal haze value, thereby calculating the internal haze value of the hard coat layer of the light-

Finally, the external haze value of the hard coat layer of the light-scattering hard coat film is calculated by subtracting the internal haze value from the total haze value.

(6) Evaluation of flammability

A sample in which a hard coat film was stuck to an acrylic resin blackboard (manufactured by Sumitomo Chemical Co., Ltd.) with an acrylic pressure-sensitive adhesive interposed therebetween was visually observed under a fluorescent lamp, and the flicker resistance was evaluated according to the following criteria.

?: Sufficient antireflection property of fluorescent lamp, and no fading

?: The antireflection property of the fluorescent lamp is slightly lowered or slightly fading is observed

C: Insufficient antireflective property of a fluorescent lamp or sufficient antireflection property of a fluorescent lamp, but exhibited a large discoloration and poor visibility

(7) 60 ° specular gloss

The measurement is carried out in accordance with JIS K 7105 using a gloss meter &quot; VG2000 &quot; manufactured by Nippon Denshoku Kogyo Co.,

(8) Thickness of hard coat layer

For each of the anti-glare hard coat film produced in Examples and Comparative Examples and the TAC (triacetyl cellulose) film which is a transparent plastic film used for producing the anti-glare hard coat film, a static pressure gauge (manufactured by Nikon Corporation, Quot; MH-15M &quot;), and the thickness of the hard coat layer is calculated by taking the difference therebetween.

&Lt; Preparation Example 1 Hard coat layer coat >

(A) an active energy beam-sensitive composition comprising a total active energy ray-curable type composition containing a hard coat agent [trade name: "Obstar Z7524", solid content concentration: 70 mass% 100 parts by mass of a compound (65% by mass, photopolymerization initiator: 5% by mass, methyl ethyl ketone: 30% by mass, refractive index of a cured product: 1.50), polymethylmethacrylate microparticles PMMA fine particles ") 7.5 parts by mass (product name: MX500, average particle diameter 5 μm, refractive index: 1.49, product of Soken Chemical Co., Ltd.), (C) silicone resin fine particles 2 parts by mass of an average particle diameter of 2 占 퐉 and a refractive index of 1.43], (D) a caprolactone-polyethylene glycol-caprolactone- Dibutyl 1 part by mass of a propylene glycol monomethyl ether copolymer (product name: "disperbyk103", product of Big Chemie Japan, diluted with 40% by mass of methoxypropyl acetate) and 90 parts by mass of propylene glycol monomethyl ether as a diluting solvent were uniformly mixed, About 40% by mass of a hard coat layer was prepared.

&Lt; Preparation Example 2 Hard coat layer coat >

(C) A hard coat layer coat (2) having a solid content of about 40% by mass was prepared by carrying out the same operations as in Preparation Example 1 except that 4 parts by mass of "Tosulfur 120" was used as the spherical silicon-base fine particles.

Preparation Example 3 Hard coat layer coat Third:

(C) Spherical silicon-based fine particles were prepared in the same manner as in Preparation Example 1 (1) except for using silicon-based fine particles (product of Momentive Performance Materials Co., Ltd., trade name: TOPSPLE 145, average particle diameter 4.5 탆, refractive index 1.43) , A hard coat layer coat No. 3 having a solid content of about 40% by mass was prepared.

&Lt; Preparation Example 4 Hard coat layer coat >

(C) Four parts by mass of hollow silica fine particles (manufactured by ABC NANOTECH Co., Ltd., product name: SI-130, average particle diameter 3 μm, refractive index: 1.46) were used as spherical silicon-based fine particles. , And a hard coat layer coat No. 4 having a solid content of about 40% by weight.

&Lt; Preparation Example 5 Hard coat layer coat >

(C) Four parts by mass of porous silica fine particles [product of ABC NANOTECH, product name: SI-230, average particle diameter 3 μm, refractive index 1.46] were used as spherical silicon-based fine particles. , And a hard coat layer coat No. 5 having a solid content of about 40% by weight.

&Lt; Preparation Example 6 Hard coat layer coat 6 >

(C) Hard coat layer coat No. 6 having a solid content of about 40% by mass was prepared by carrying out the same operations as in Preparation Example 1 except that spherical silicon-based particles were not used.

&Lt; Preparation Example 7 Hard coat layer coat 7 >

(C) spherical silicon-based fine particles and (D) a surfactant were not used, a hard coat layer coating 7 having a solid content of about 40% by mass was prepared.

&Lt; Preparation Example 8 Hard coat layer coat 8 >

A hard coat layer coat No. 8 having a solid content of about 40% by mass was prepared by carrying out the same operations as in Preparation Example 2, except that (D) a surfactant was not used.

&Lt; Preparation Example 9 Hard coat layer coat >

A hard coat layer coat No. 9 having a solid content of about 40% by mass was prepared by carrying out the same operations as in Preparation Example 3 except that (D) a surfactant was not used.

&Lt; Preparation Example 10 Hard coat layer coat >

(B) The same procedure as in Preparation Example 2 was carried out except that spherical organic fine particles were not used, to thereby prepare a hard coat layer coating 10 having a solid content of about 40% by mass.

<Preparation Example 11 Hard coat layer coat No. 11>

(B) The same procedure as in Preparation Example 3 was carried out except that spherical organic fine particles were not used, to thereby prepare a hard coat layer coat No. 11 having a solid content of about 40% by mass.

&Lt; Preparation Example 12 Hard Coat Layer Coat No. 12 >

(B) The same procedure as in Preparation Example 4 was carried out except that spherical organic fine particles were not used, to prepare a hard coat layer coating 12 having a solid content of about 40% by mass.

&Lt; Preparation Example 13 Hard Coat Layer Coat No. 13 >

(B) The same procedure as in Preparation Example 5 was carried out except that spherical organic fine particles were not used, to prepare Coat No. 13 for hard coat layer having a solid content of about 40% by mass.

Table 1 shows the properties of the hard coat layer coatings 1 to 13 obtained in Preparation Examples 1 to 13.

Example 1

First coat of the hard coat layer obtained in Preparation Example 1 was applied to the surface of a TAC film (trade name: "TAC80TD80ULH", product of Fuji Film Co., Ltd.) having a thickness of 80 μm to give a cured film thickness of about 10 μm. Dried in an oven at 70 deg. C for 1 minute, and then irradiated with ultraviolet light having a light intensity of 30 mJ / cm &lt; 2 &gt; with a high-pressure mercury lamp to form a hard coat layer to produce a flash-resistant hard coat film.

The performance of this hard coat film is shown in Table 2.

Examples 2 to 5, Comparative Examples 1 to 7 and Reference Example 1

The same operations as in Example 1 were carried out except that the hard coat layer coating agents of the kind shown in Table 2 were used in place of the hard coat layer first coat in Example 1 to produce various types of hard- Respectively.

Table 2 shows the performance of each hard coat film.

In the above Tables 1 and 2, the following can be known.

The antiglare hard coat film of the present invention obtained in Examples 1 to 3 is a film in which the inner haze value is changed mainly even when the content of the spherical silicon fine particles of component (C), which is hardly affected by the surfactant (D) , The external haze value does not change much. In Examples 4 and 5, even when porous silicon or hollow silica is used as the spherical silicon-based fine particles of the component (C), the effect of imparting anti-glare properties is excellently exerted.

In Reference Example 1, since the refractive index difference between the cured product of the component (A) and spherical organic fine particles of the component (B) is small, the internal haze is small. On the other hand, Examples 1 to 3 contain silicon-containing fine particles of the component (C) having a difference in refractive index from the cured component (A), thereby exhibiting internal haze. In Comparative Examples 1 to 3, since the surface active agent is not contained, the film thickness (10 μm) of the hard coat layer larger than the average particle diameter has insufficient flicker resistance.

As in Comparative Examples 4 to 7, the spherical silicon-based fine particles of the component (C) which are not influenced by the surfactant are insufficient in the retardation in the film thickness of the hard coat layer larger than the average particle diameter of the particles.

The hard coat film of the present invention has a hard coat layer containing spherical organic fine particles and spherical silicon fine particles and has antiscratching property and is capable of changing the internal haze value without significantly changing the external haze value So that the adjustment of the external / internal haze value at the time of film production can be easily performed, and the desired antiglare property can be obtained without deteriorating the contrast. The anti-glare hard-coat film of the present invention is particularly suitable as a polarizing plate.

1: Polyvinyl alcohol polarizer 2, 2 ', 12, 12': TAC film
3, 16: pressure-sensitive adhesive layer 4, 17: peeling sheet
5: surface protective film 10, 20: polarizer
11: polarizer 13: hard coat layer
14: repellent hard coat film 15, 15 ': adhesive layer

Claims (6)

A method for producing a transparent plastic film, comprising the steps of: (A) applying an active energy beam-sensitive composition containing (a) a polyfunctional (meth) acrylate monomer and / or a (meth) acrylate- (B) at least one spherical organic fine particle selected from an acrylic resin having an average particle diameter of 1 to 10 μm, an acrylic-styrene resin, a melamine resin, a polycarbonate resin, a styrene resin and a vinyl chloride resin, C) at least one spherical silicon-based fine particle selected from a silicone resin having an average particle size of 0.5 to 10 μm, hollow silica and porous silica, and (D) a surfactant, Wherein the component (D) is a N, N-dialkylaminoalcohol-modified polyoxyalkylene glycol, and the thickness of the hard coat layer is in the range of from 0.1 to 10 parts by weight, (C) &lt; / RTI &gt; Wherein the hard coat film has an average grain size larger than that of the hard coat film. The method according to claim 1,
(b) a silica-based fine particle is a silica fine particle having a group containing a (meth) acryloyl group as a surface functional group. 3. The method according to claim 1 or 2,
Wherein the refractive index difference between the cured product of the component (A) and the component (B) is less than 0.02, and the refractive index difference between the cured product of the component (A) and the component (C) . A polarizing plate characterized in that the opposite side of the hard coat layer forming surface of the light-scattering hard coat film described in claim 1 or 2 is bonded to a polarizer. A polarizing plate characterized in that the opposite side of the hard coat layer formation side of the light-scattering hard coat film according to claim 3 is bonded to a polarizer. The method according to claim 1,
, The average particle diameter of the component (B) is 2 to 8 占 퐉, and the average particle diameter of the component (C) is 2 to 6 占 퐉.

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