JP2007041547A - Optical film, antireflection film, polarizing plate and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably provide an optical film and an antireflection film excellent in antiglare effect and giving well-defined black of a screen when applied to a display, and to provide a polarizing plate subjected to antireflective treatment by a proper means, and an image display device. <P>SOLUTION: The optical film has, on a transparent support, a light diffusion layer formed by applying and curing a coating composition for a light diffusion layer containing an ionizing radiation-curable monomer, at least two kinds of light transmissive resin particles different from each other in average particle diameter, and at least two organic solvents, wherein the light transmissive resin particles have particle species of which the average particle diameter is maximum and second particle species of which the average particle diameter is 30-90% of that of the maximum particle species, and the average particle diameter of the maximum particle species is in a range of 20-90% of the thickness of the light diffusion layer after curing. The polarizing plate and the image display device using the optical film are obtained. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical film, a polarizing plate using the same, and an image display device.

In recent years, liquid crystal display devices (LCDs) have been increased in screen size, and liquid crystal display devices provided with an optical film, for example, an antireflection film, have been increasing.
Optical films are used in various image display devices such as liquid crystal display devices (LCD), plasma display panels (PDP), electroluminescence displays (ELD), and cathode ray tube display devices (CRT) to reflect external light and reflect images. In order to prevent the contrast from being lowered due to the inclusion, it is arranged on the surface of the display. A light diffusing layer may be installed as one means for imparting antireflection ability to the optical film. By including translucent particles in this layer, anti-glare properties and the like are exhibited as one of the effects. The antiglare property greatly depends on the surface shape of the optical film, and the translucent particles contained in the light diffusion layer increase the surface unevenness, thereby scattering the reflected light and reducing the reflection of the image. In addition, the light diffusing layer may have a function to suppress the gradation reversal at the wide angle of the display and widen the viewing angle, and while exhibiting such a function, the resolution and darkness of the screen are not reduced. Thus, the material and optical characteristics of the light diffusion layer are adjusted.
For example, there are methods of using fine particles, a solvent-drying resin, and an ultraviolet curable resin in combination in the antiglare layer, and controlling the standard deviation of the fine particles. (Patent Document 1) or a method of defining a refractive index and a particle size between a layer binder and particles by containing a plurality of particles in a light diffusion layer is also known. (Patent Document 2)
However, particularly when attention is focused on improving the blackening of the screen, it is not sufficient to simply use a plurality of translucent particles and combine these usage methods, and further improvement of the usage methods has been desired.

On the other hand, a polarizing plate is an indispensable optical material in a liquid crystal display device, and generally has a structure in which a polarizing film is protected by two protective films.
If an antireflection function can be imparted to these protective films, significant cost reduction and thinning of the display device can be achieved.
Therefore, it is desired to solve the above problems in these protective films.
The protective film used for the polarizing plate needs to have sufficient adhesion to be bonded to the polarizing film. As a method for improving the adhesion to the polarizing film, it is common practice to saponify the protective film to hydrophilize the surface of the protective film.
Japanese Patent Laid-Open No. 10-20105 JP 2003-114304 A

  An object of the present invention is to stably provide an optical film and an antireflection film that are excellent in antiglare properties and have a good feeling of blackening on a screen when applied to a display, and are further subjected to antireflection treatment by appropriate means. It is providing a polarizing plate and an image display apparatus.

  The above-described problems have been achieved by an optical film, a polarizing plate, and an image display device having the following configuration.

(1) Post-curing after applying a coating composition for a light diffusing layer comprising an ionizing radiation curable monomer, at least two kinds of translucent resin particles having different average particle diameters, and at least two kinds of organic solvents on a transparent support. An optical film having a light diffusing layer, wherein, in the translucent resin particles, a particle type having a maximum average particle size and a second average particle size of 30 to 90% with respect to the maximum particle type An optical film characterized in that the average particle size of the largest particle type is in the range of 20 to 90% with respect to the thickness after curing of the light diffusion layer.
(2) In the translucent resin particles contained in the light diffusion layer, the average particle size of the particle type having the maximum average particle size is 2 to 20 μm. .
(3) Among the translucent resin particles contained in the light diffusion layer, the average particle size of the particle type having the maximum average particle size is 3 to 7 μm (1) or (2) The optical film described in 1.
(4) The value when the dispersity (V) of the total particle of the translucent resin particles contained in the light diffusion layer is expressed by the following formula A is V = 0.6 to 1.0. The optical film according to any one of (1) to (3).
Formula A
V = (90% volume cumulative particle diameter−10% volume cumulative particle diameter) / 50% volume cumulative particle diameter (5) The average value of the I / O values of the ionizing radiation-curable monomer, and the translucent resin particles The optical film according to any one of (1) to (4), wherein the difference from the average I / O value is 0.3 to 3.0.

(6) The optical system according to any one of (1) to (5), wherein the at least two organic solvents have at least one combination having a difference in I / O value of 0.25 or more. the film.
(7) The optical film as described in any one of (1) to (6), wherein a boiling point of at least one of the at least two organic solvents is 160 to 250 ° C.
(8) Any of (1) to (7), wherein the ionizing radiation curable monomer is at least two types, and at least one of them is a monomer having an I / O value of 1.2 or more. The optical film described in 1.
(9) The optical film as described in (8), wherein the ionizing radiation curable monomer having an I / O value of 1.2 or more is a monomer having an ethylene oxide group added thereto.
(10) A curable multi-branched polymer having a photo-curable and / or thermosetting reactive group at the terminal of the multi-branched polymer (HB), wherein the light diffusing layer cured after applying the coating composition for a light diffusing layer ( (RHB) is contained, The optical film in any one of (1)-(9) characterized by the above-mentioned.
(11) The optical film as described in (10), wherein the multi-branched polymer (HB) is at least one selected from the group consisting of a dendrimer, a hyperbranched polymer and a starburst polymer.
(12) The photocurable and thermosetting reactive group of the curable multi-branched polymer (RHB) is at least one selected from a radical polymerizable group, a cationic polymerizable group, and a hydrolyzable silyl group. (10) The optical film as described in (11) characterized by these.
(13) Polyester polyol dendrimer compound (a) having 6 or more hydroxyl groups in one molecule and ethylenically unsaturated in terms of solid content in the light diffusing layer cured after coating the light diffusing layer coating composition The optical film according to any one of (1) to (12), comprising an ethylenically unsaturated group-containing polyester dendrimer (A) that is a reaction product with the group-containing monocarboxylic acid (b).

(14) The above (1) to (13), wherein any layer on the transparent support contains at least one of an organosilane compound represented by the following general formula [A] and a derivative thereof. ).

Formula [A] (R ¹⁰ ) _a -Si (Z) _4-a

In the general formula [A], R ¹⁰ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. Z represents a hydroxyl group or a hydrolyzable group. a represents an integer of 1 to 3.
(15) The optical film as described in any one of (1) to (14) above, which has a low refractive index layer formed by crosslinking or polymerization reaction of a fluorine-containing compound represented by the following general formula 1. .

In General Formula 1, L represents a linking group having 1 to 10 carbon atoms, and b represents 0 or 1. X ¹ represents a hydrogen atom or a methyl group. A represents a polymerized unit of any vinyl monomer, and may be a single polymerized unit or a plurality of polymerized units. x1, y, and z each represent a mol% of each constituent polymerization unit, and represent values satisfying 30 ≦ x1 ≦ 60, 5 ≦ y ≦ 70, and 0 ≦ z ≦ 65.
(16) The optical film as described in (15) above, wherein the low refractive index layer contains hollow silica fine particles.
(17) An antireflection film, wherein a low refractive index layer is provided on the light diffusion layer of the optical film according to any one of (1) to (16).

(18) The optical film according to any one of (1) to (16) or the antireflection film according to (17) is used for at least one of two protective films of a polarizing film. A polarizing plate.
(19) The optical film according to any one of (1) to (16), the antireflection film according to (17), or the polarizing plate according to (18) is disposed on the image display surface. An image display device characterized by the above.
(20) The image display device according to (19), wherein the image display device is a TN, STN, IPS, VA, or OCB mode transmissive, reflective, or transflective liquid crystal display device. .

  The optical film and antireflection film of the present invention are excellent in antiglare properties and have a good feeling of darkness on the screen when applied to a display. In addition, the polarizing plate and the image display device of the present invention can obtain a high-quality image with excellent visibility due to the above effects.

In this specification, when a numerical value represents a physical property value, a characteristic value, or the like, the description “(numerical value I) to (numerical value II)” means “(numerical value I) to (numerical value II)”. The description “(meth) acryloyl” means “at least one of acryloyl and methacryloyl”. The same applies to “(meth) acrylate”, “(meth) acrylic acid” and the like.
Hereinafter, the present invention will be described in more detail.

(Layer structure)
For the optical film of the present invention, for example, the following known layer structures can be used.
For example, as a typical example, transparent support / light diffusion layer transparent support / light diffusion layer / low refractive index layer transparent support / hard coat layer / low refractive index layer transparent support / hard coat layer / medium refractive index Layer / high refractive index layer / low refractive index layer.
As a layer that may be provided between the transparent support and the surface layer, a light diffusing layer, an antistatic layer (when there is a request to reduce the surface resistance value from the display side, dusting on the surface, etc. becomes a problem. ), A hard coat layer (when the light diffusion layer alone is insufficient in hardness), a low refractive index layer, a moisture-proof layer, an adhesion improving layer, a rainbow unevenness (interference unevenness) preventing layer, and the like. Moreover, you may install the antifouling layer containing a slip agent etc. on a low refractive index layer. When the light diffusion layer is used on the transparent support and the hardness is insufficient only by the light diffusion layer, a hard coat layer may be provided between the transparent support and the light diffusion layer.
The antistatic layer is preferably in contact with the transparent support, but can be disposed at other positions.
By forming a low refractive index layer on the light diffusion layer with a film thickness of about ¼ of the wavelength of light, surface reflection can be reduced by the principle of thin film interference.
Further, the light diffusion layer can also have an antiglare function, and in the present invention, the light diffusion layer is mainly referred to as a layer in which both functions are integrated. The light diffusion layer preferably has a hard coat property and a high refractive index property in addition to the antiglare property and the light diffusibility. Although the light diffusion layer may be a single layer, it may be composed of a plurality of layers, for example, 2 to 4 layers. Moreover, although you may provide directly on a transparent support body, you may provide via other layers, such as an antistatic layer and a moisture-proof layer.
Further, the light diffusion layer may be, for example, the hard coat layer in the above example.
In the present invention, the layer farthest from the support may be referred to as the outermost layer. When the low refractive index layer is located at the outermost layer, the low refractive index layer is the outermost layer, and the antifouling layer is located at the outermost layer. The antifouling layer is the outermost layer.
The optical film of the present embodiment mainly includes, for example, a transparent support, a light diffusion layer formed on the transparent support, and a low refractive index layer formed on the light diffusion layer, in this order. In addition, there is a case where an antifouling layer for preventing the adhesion of dirt on the surface is provided outside the low refractive index layer. The light diffusion layer is mainly composed of a translucent resin and translucent fine particles dispersed in the translucent resin.
In the above example, the refractive index of each layer constituting the optical film preferably satisfies the following relationship.
Refractive index of (high) light diffusion layer> refractive index of transparent support> refractive index of low refractive index layer (low)

<Light diffusion layer>
The light diffusion layer is mainly composed of a light-transmitting polymer formed by curing monomers with ionizing radiation, etc., a curable multi-branched polymer (RHB), a light-transmitting resin particle, and a higher refractive index if necessary. Alternatively, it is formed from a fine inorganic filler for lowering the refractive index, preventing crosslinking shrinkage, and increasing the strength, and a polymer compound (B) described later.
The thickness of the light diffusion layer is usually about 0.5 μm to 30 μm, preferably 1 μm to 15 μm, and more preferably 3 μm to 10 μm. When the thickness is in the above range, there are no defects such as curling, haze value, and high cost, and it is easy to adjust the antiglare property and the light diffusion effect.

[binder]
The refractive index of the binder is preferably 1.40 to 2.00, more preferably 1.45 to 1.90, still more preferably 1.48 to 1.85, and particularly preferably 1.51. ~ 1.80. In addition, the refractive index of a binder is the value measured by remove | excluding translucent particle | grains from the component of the light-diffusion layer.
It is preferable to add the binder of a light-diffusion layer in 20-95 mass% with respect to the solid content of the coating composition of this layer.

[Main binder]
The main binder for forming the light diffusion layer is preferably a light-transmitting polymer having a saturated hydrocarbon chain or a polyether chain as the main chain after curing such as ionizing radiation, and a polymer having a saturated hydrocarbon chain as the main chain. More preferably it is. The cured main binder polymer preferably has a crosslinked structure.
As the binder polymer having a saturated hydrocarbon chain as a main chain after curing, a polymer of an ethylenically unsaturated monomer (binder precursor) is preferable. As the binder polymer having a saturated hydrocarbon chain as the main chain and having a crosslinked structure, a (co) polymer of monomers having two or more ethylenically unsaturated groups is preferable.
In order to obtain a high refractive index, the monomer structure preferably contains an aromatic ring or at least one atom selected from halogen atoms other than fluorine, sulfur atoms, phosphorus atoms, and nitrogen atoms.

Examples of the ionizing radiation curable monomer for forming the light diffusing layer include monomers having two or more ethylenically unsaturated groups. Examples of such monomers include polyhydric alcohol, (meth) acrylic acid, (Eg, ethylene glycol di (meth) acrylate, glycerin tri (meth) acrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetra (meth) acrylate), pentaerythritol tri (meth) acrylate, trimethylolpropane tri ( (Meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol Hexa (meth) acrylate, 1,2,3-chlorohexanetetramethacrylate, polyurethane polyacrylate, polyester polyacrylate), vinylbenzene and its derivatives (eg, 1,4-vinylbenzene, 4-vinylbenzoic acid-2-acryloyl) Examples include ethyl ester, 1,4-vinylcyclohexanone), vinyl sulfone (eg, divinyl sulfone), acrylamide (eg, methylene bisacrylamide) and methacrylamide.
Furthermore, resins having two or more ethylenically unsaturated groups, such as relatively low molecular weight polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins And oligomers or prepolymers of polyfunctional compounds such as polyhydric alcohols. Two or more of these monomers may be used in combination, and the resin having two or more ethylenically unsaturated groups is preferably contained in an amount of 10 to 70% based on the total amount of the binder.

  Specific examples of the high refractive index monomer include bis (4-methacryloylthiophenyl) sulfide, vinyl naphthalene, vinyl phenyl sulfide, 4-methacryloxyphenyl-4′-methoxyphenyl thioether, and the like. Two or more of these monomers may be used in combination.

In addition, the ionizing radiation curable monomer according to the present invention has a difference between the average value of the translucent resin particles and the I / O value of 0.3 to 0.3 as the average value of the total monomers in order to easily control the antiglare property. 3.0, more preferably 0.5 to 2.5 is more preferable.
The average value of the I / O values of the translucent resin particles was determined as the sum of the values obtained by multiplying the content of each particle type by the respective I / O values.
Thus, as a monomer for controlling the I / O value, a monomer having an I / O value of 1.2 or more, preferably 1.4 to 3.0 is used from the viewpoint of particle aggregation and post-curing film strength. It is preferable to contain 10 mass%-60 mass% with respect to all the monomers, It is more preferable to contain 20 mass%-55 mass%, It is more preferable to contain 30 mass%-50 mass%. If the amount used exceeds this range, the film strength after curing will deteriorate. Examples of such an I / O value controlling monomer include monomers obtained by adding an ethylene oxide group to the polyfunctional monomer. For example, for a monomer having an I / O value of 1 or less, the I / O value can be increased by increasing the amount of ethylene oxide group added.

The I / O value according to the present invention was determined by the method described in Satoshi Fujita “Organicity: Organic Concept by Inorganic Value”, Yoshio Koda “Organic Conceptual Diagram” Sankyo Publishing (1984), etc. Inorganic (I) / organic (O) "value. The I / O value is used as one of means for predicting various physicochemical properties of an organic compound. Organicity can be obtained by comparing the number of carbons, and inorganicity can be obtained by comparing the boiling points of hydrocarbons having the same number of carbons. For example, one (—CH ₂ —) (actually C) is determined to have an organic value of 20, and the inorganic property is determined to have an inorganic value of 100 from the influence of the hydroxyl group (—OH) on the boiling point. . What calculated | required the value of the other substituent (inorganic group) on the basis of the inorganic value 100 of this (-OH) is shown as an "inorganic group table."

[Curable multi-branched polymer (RHB)]
In the present invention, the light diffusing layer as a binder component is a curable multi-branched polymer (RHB) having a multi-branched polymer (HB) as a nucleus and a photo-curable and / or thermosetting reactive group at the end of the branched branch. It is preferable to include. Moreover, it is preferable to contain at least one of a curing agent, a curing accelerator and a polymerization initiator in combination with the main binder.
Furthermore, the photocurable and / or thermosetting reactive group contained in the curable multi-branched polymer (RHB) is selected from a radical polymerizable group, a cationic polymerizable group, and a hydrolyzable group-substituted silyl group. It is preferably a curable reactive group (hereinafter sometimes simply referred to as a curable group). It is preferable to further contain a polymerizable compound copolymerizable with these polymerizable groups and a polymerization initiator.

(Multi-branched polymer (HB))
A multibranched polymer (HB) serving as a nucleus is a compound that is bonded to a branched chain extension unit that is two or more regular dendritic branches with a polyvalent base nucleus as a center. The polyvalent group nucleus is a compound having at least two reactive groups (a) that form a linking group. The linking group is chemically bonded to the reactive group (a) of the compound serving as the group nucleus. A hyperbranched polymer having a structure extended by repeating a chemical reaction between one reactive group (b) that forms a compound and a compound having at least two reactive groups (a) (branched chain extension compound) Preferably there is.

The polyvalent group nucleus of the multi-branched polymer (HB) serving as the nucleus (core) is not particularly limited as long as it is a polyfunctional compound having an organic residue, a nitrogen atom, a silicon atom or a phosphorus atom as a nucleus. Examples of the organic residue include a heterocyclic structure having a monocyclic or polycyclic ring structure containing at least one heteroatom selected from a carbon atom, an aromatic hydrocarbon ring, oxygen, nitrogen, and sulfur. .

The multibranched polymer (HB) serving as a core is preferably a molecule prepared by a polycondensation cycle. Each cycle involves reacting all of the reactive functional groups of the core with one equivalent of a branched chain extending compound. Depending on the number of cycles (n), it is referred to as an “nth generation” hyperbranched molecule. In the present invention, the first to sixth generations are preferred. The second generation to the fourth generation are particularly preferable.
The multi-branched polymer (HB) preferably contains a cyclic structure selected from an alicyclic ring structure and an aromatic ring structure in the branched chain extension unit. Further, it preferably contains a cyclic structure (also referred to as a ring structure) and an alkylene chain structure composed of an alkylene group having 1 to 22 carbon atoms.

In the branched branch of the multi-branched polymer (HB), the reactive group (a) having reactivity with the branch extension compound has a terminal structure. Examples of the reactive group (a) at the branched branch end include a carboxyl group, a hydroxyl group, an amino group, an epoxy group, and a thiol group. In the present invention, a hydroxyl group is preferable from the viewpoint of dispersibility of the translucent resin fine particles. The core multi-branched polymer used in the present invention preferably has 6 to 128 groups of reactive groups (a) at the ends of the branched branches, and more preferably has 8 to 64 groups. .
The weight average molecular weight is generally about 1,000 to about 50,000, preferably about 1500 to about 20,000. Within this range, the curing reaction proceeds sufficiently and the film strength of the obtained cured film can be maintained.

  More specifically, the multi-branched polymer (HB) serving as a core is preferably composed of at least one selected from the group consisting of dendrimers, hyperbranched polymers, and starburst polymers.

  Specific examples of the multi-branched polymer (HB) include multi-branched polyurea, multi-branched polyurethane, multi-branched polyamide amine, multi-branched polyamide, multi-branched polyester, multi-branched polycarbonate, multi-branched polycarbosilane, multi-branched polycarbosiloxane, Examples include multi-branched polycarbosilazenes, multi-branched polyethers, multi-branched poly (ether ketones), multi-branched poly (propylene imines), multi-branched polyalkylamines, and copolymers thereof.

  Preferred examples include multi-branched polyamidoamines, multi-branched polyamides, multi-branched polyesters, multi-branched polycarbosilanes, multi-branched polycarbosiloxanes, multi-branched polyethers, multi-branched poly (ether ketones), and multi-branched polyalkylamines.

  Such multi-branched polymers are, for example, edited by Yasuhiko Okada, “Science and Function of Dendrimers” pp 29-31 (IPC Co., Ltd., 2000), ibid, Chapter 2, edited by Koji Ishizu, “ Nanotechnology "Chapter 6 (IPC Co., Ltd., 2000), COMPREHENSIVE SUPERMOLECULAR 10, Chapter 26 (PeramonPress, New York, 1995), and the like can be mentioned.

  Furthermore, D.C. A. Tomalia, et al., “Angew. Chem. Int. Ed. Engl.”, 29, 138 (1990); , “Advanceds in Polymer Science”, Volume 143, 1 (Springer, New York) (1999); C. Salamone, Ed. , “Polymeric Materials Encyclopedia,” Volume 30, page 4949 (CRC Press, published by New York (1996); Masaaki Enomoto, “Polymer”, Volume 47, page 804 (1998), and references cited in the above-mentioned books, etc. The contents described in.

As the multi-branched polymer (HB) as a core, for example, in the case of a polyamino-based multi-branched polymer, for example, a reaction in which butylene diamine and acrylonitrile are reacted and a terminal nitrile group is reduced to an amine is made one step, and this reaction is repeated. Propyleneimine-based multibranched polymer obtained by the above (WO093 / 14147, US5,530,092 specification, Japanese Examined Patent Publication No. 7-330631); ring-opening polymerization reaction using amine as a nucleophilic component and using a palladium catalyst Amine-based multibranched polymer {M. Suzuki, et al. , “Macromolecules”, Vol. 31, p. 1716 (1998)}; Michael addition of methyl acrylate to ammonia or ethylenediamine, and further introducing a secondary amino group at the terminal by ester amide exchange reaction as one step, if necessary And an amidoamine-based multibranched polymer obtained by repeated reaction (WO0884705, JP-B-6-70132); polyamide-based multibranched polymer {S. C. E. Backson, et al. , “Macromol. Symp.”, Vol. 77, page 1 (1994), JP-A 2000-86758, JP-A 2000-256459, etc.}; polyphenylene ester-based multibranched polymer {K. L. Wooley, et al. , “Polymer Journal”, Vol. 26, 187 (1994)}; polyetherketone-based multibranched polymers {C. J. et al. Hawker, “Macromolecules”, 29, 4370 (1996)}; polyurethane or polyurea based multibranched polymers {R. Spindler, “Macromolecules”, 26, 4809 (1993), A.M. Kumar, “Chem. Commun.”, 1629 (1998), etc.}; polyether-based multibranched polymers {V. Percec et al. “Macromolecules”, 27, 4441 (1994), C.I. J. et al. Hawker, et al. “J. Am. Chem. Soc.”, 112, 7638 (1990), JP-A-2001-206886, JP-A-2002-37823, etc.}; polyester-based multibranched polymer terminated with a hydroxyl group (US5) 418,301 specification, WO096 / 12754, JP 2003-522266, etc.); polyester-based multibranched polymer terminated with a carboxyl group (SR Turner, et al. “Macromolecules”, Vol. 27) 1611 (1994), JP-A-11-60540, etc.); polyester-based multibranched polymers terminated with a group containing an epoxy group (US Pat. No. 5,663,247, WO096 / 13558, etc.) it can.
Furthermore, “BOLTORN” (trade name, manufactured by Perstorp) of aliphatic polyester-based multi-branched polymers, “STARBURST” (polystyrene-based multi-branched polymers (manufactured by DSM), poly (amidoamine) multi-branched polymers ( Commercially available products such as “PAMAN” and “Dendrimer” (trade name, manufactured by Aldrich) can be used.

(Curable multi-branched polymer (RHB))
The curable multi-branched polymer (RHB) used in the present invention has a photo-curing property and a heat which can be involved in a crosslinking reaction by light and / or heat at least part of the branched end of the multi-branched polymer (HB). It contains a curable reactive group (hereinafter sometimes simply referred to as a curable group), has a multi-branched polymer (HB) as a core (core), and is 10 mol% to It is a highly “branched (dendritic)” macromolecule with 90% by mole of photo-curing and / or thermosetting reactive groups attached.

Examples of the curable group possessed by the curable multi-branched polymer (RHB) include a group having an active hydrogen atom (for example, hydroxyl group, carboxyl group, amino group, carbamoyl group, mercapto group, β-ketoester group, hydrosilyl group, silanol). Group), radical polymerizable group having an unsaturated double bond capable of radical polymerization (eg, acryloyl group, methacryloyl group, vinyl group, etc.), cationic polymerizable group (eg, epoxy group, oxetanyl group, etc.), Acid anhydride-containing groups, hydrolyzable silyl groups (eg alkoxysilyl groups, acyloxysilyl groups, etc.), groups that can be displaced by nucleophiles (active halogen atoms, sulfonate esters, etc.), isocyanate groups (protected It can be a block isocyanate group that generates an isocyanate group by heating. ), And the like.
In particular, it is preferably at least one selected from a radical polymerizable group, a cationic polymerizable group, and a hydrolyzable silyl group, and most preferably selected from radical polymerizable groups.

  10 mol% to 90 mol% of the total number of branches of the multi-branched polymer (HB) (hereinafter sometimes simply referred to as “core molecule”) as a core contains a curable group. preferable. Thereby, sufficient film strength is exhibited, and dispersibility of the translucent resin fine particles is ensured. More preferably, it is 50 mol%-90 mol%.

Further, the curable groups in the molecule may be the same or different and may contain, for example, at least one polymerizable group selected from a radical polymerizable group, a cationic polymerizable group, and a hydrolyzable silyl group. .
Further, it may be a structure in which a non-polymerizable hydrocarbon group is bonded to a part of all branched branches, that is, a structure chemically modified with another non-polymerizable linking group.

  The curable multi-branched polymer (RHB) used in the present invention synthesizes a multi-branched polymer as a core by a synthesis method such as a conventionally known stepwise synthesis method (Divergent method) or polycondensation reaction of an ABx type compound, This polar group terminal polar group can be obtained by modifying with a specific substituent according to a conventionally known synthesis method. Further, a curable multi-branched polymer (RHB) can also be obtained by a synthesis method according to the description in Japanese Patent No. 2574201.

  As the antireflection film of the optical film for image display, the curable multi-branched polymer (RHB) is preferably non-absorbing in the wavelength range of 400 nm to 650 nm from the viewpoint of maintaining transparency without being colored. . The light transmittance in the wavelength range of 400 nm to 650 nm as a film is preferably 85% or more and 100%, more preferably 90% or more and 100%.

As a more preferred example of the curable multi-branched polymer [RHB] used in the light diffusion coating composition constituting the light diffusion layer in the present invention, an ethylenically unsaturated group-containing polyester dendrimer (A) can be mentioned.
The ethylenically unsaturated group-containing polyester dendrimer (A) is obtained by reacting a polyester polyol dendrimer compound (a) having 6 or more hydroxyl groups in one molecule with an ethylenically unsaturated group-containing monocarboxylic acid (b). can get.

  The polyester polyol dendrimer compound having 6 or more hydroxyl groups in one molecule is not particularly limited as long as it is a polyester polyol having a molecular structure highly branched by an ester bond and most of the terminal groups are hydroxyl groups. Is a compound represented by the following general formula (1), and specifically, for example, BOLTORN H20, BOLTORN H30, BOLTORN H40, BOLTORN H2003, BOLTORN H2004, BOLTORN P1000 (all manufactured by Pelstorpor-Pae) can give.

[Wherein, X ₁ represents a dimethylolpropionic acid residue or a hydrogen atom, and c represents an integer of 1 to 10]

  Examples of ethylenically unsaturated group-containing monocarboxylic acids (b) include reaction products of acrylic acids, crotonic acid, α-cyanocinnamic acid, cinnamic acid, saturated or unsaturated dibasic acids and unsaturated group-containing monoglycidyl compounds Etc.

  Examples of the acrylic acids include acrylic acid, a dimer of acrylic acid, methacrylic acid, β-styrylacrylic acid, β-furfurylacrylic acid, saturated or unsaturated dibasic acid anhydride, and one per molecule. Half-esters which are equimolar reaction products with a (meth) acrylate derivative having a hydroxyl group, half-esters which are equimolar reaction products of saturated or unsaturated dibasic acid and monoglycidyl (meth) acrylate derivatives, etc. Preferably, acrylic acid is mentioned.

Half-esters which are equimolar reactants of a saturated or unsaturated dibasic acid anhydride and a (meth) acrylate derivative having one hydroxyl group in one molecule include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate or 1,4-butanediol mono (meth) acrylate and the like and dibasic acid anhydrides (for example, succinic anhydride, maleic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydro anhydride) And a half ester which is a reaction product with phthalic acid).
The half-esters which are equimolar reactants of a saturated or unsaturated dibasic acid and monoglycidyl (meth) acrylate derivatives include, for example, the dibasic acid in the reaction product of glycidyl methacrylate and (meth) acrylic acid. A product obtained by reacting an anhydride is also included.
Examples of the reaction product of a saturated or unsaturated dibasic acid and an unsaturated group-containing monoglycidyl compound include a phenyl diglycidyl ether compound, a bisphenol type epoxy compound, a hydrogenated bisphenol type epoxy compound, and an alicyclic diglycidyl ether compound. An aliphatic diglycidyl ether compound, a polysulfide type diglycidyl ether compound, a biphenol type epoxy compound, a bixylenol type epoxy compound, an epoxy compound having a halogenated bisphenol skeleton or an epoxy compound having a halogenated biphenol skeleton and (meth) acrylic acid, Examples of the product obtained by reacting the dibasic acid anhydride with the reaction product are also listed.
You may use these individually or in mixture of 2 or more types.

  The ethylenically unsaturated group-containing polyester dendrimer (A) preferably contained in the light diffusion layer used in the present invention comprises the polyester polyol dendrimer compound (a) and the ethylenically unsaturated group-containing monocarboxylic acid (b). Although it is obtained by reacting, it is preferably produced by a method in which (a) and (b) are subjected to dehydration condensation in the presence of an acid catalyst such as sulfuric acid, methanesulfonic acid, p-toluenesulfonic acid and the like.

  The content of the ethylenically unsaturated group-containing polyester dendrimer (A) in the light diffusion layer after curing is small in curl, and from the viewpoint of improving flexibility, 10% by mass to 80% by mass in the solid content of the layer is Preferably, 20 mass%-70 mass% is more preferable, and 30 mass%-60 mass% is further more preferable.

(Curing agent, curing accelerator and polymerization initiator)
It is preferable that at least one of a curing agent, a curing accelerator and a polymerization initiator is used in combination in the coating composition for a light diffusion layer containing the curable multi-branched polymer used in the present invention. These can be used by appropriately selecting conventionally known ones according to the curing reaction of the curable reactive group (a) in the curable multi-branched polymer (RHB).

  As such a curing agent and a curing accelerator, for example, Shinzo Yamashita, Tosuke Kaneko “Crosslinking Agent Handbook” published by Taiseisha (1981) “Polymer Data Handbook Fundamental” edited by Taiseisha (1986) Etc.) can be used. Also, for example, organic silane compounds, polyisocyanate compounds, polyol compounds, polyamine compounds, acid anhydride compounds, polyepoxy group-containing compounds, epoxy resins {eg, “New Epoxy Resins” written by Hiroshi Horiuchi (Published in 1985), “epoxy resins” written by Kuniyuki Hashimoto, published by Nikkan Kogyo Shimbun (1969), etc., melamine resins {eg, “Yulia Melamine Resin” edited by Ichiro Miwa and Hideo Matsunaga, Nikkan Kogyo Shimbun (Compounds described in (1969)) and poly (meth) acrylate compounds {for example, Nobu Okawara, Takeo Saegusa, Toshinobu Higashimura "Oligomer" Kodansha (1976), Eizo Omori "Functional acrylics" Resins "compounds described in Techno System (published in 1985), etc.}.

For example, as the curing agent used when the curable group of the curable multi-branched polymer (RHB) is a group having an active hydrogen such as a hydroxyl group or an amino group, for example, a polyisocyanate type, aminoplast, polybasic acid or its An anhydride etc. can be mentioned.
When the curable group of the curable multi-branched polymer (RHB) is an epoxy group or an oxetanyl group, a reactive group having an active hydrogen (for example, a hydroxyl group, a carboxyl group, an amino group, a mercapto group, etc.) or a cyclic acid anhydride is contained. It can be cured by a chemical reaction with a compound having a group.

  These curing agents are preferably added in an amount of 0.5 to 300 parts by mass per 100 parts by mass of the curable multibranched polymer (RHB), and in particular, 5 parts by mass per 100 parts by mass of the curable multibranched polymer (RHB). The addition amount is preferably from 0 to 100 parts by mass.

As the curing accelerator that accelerates the curing, a known acid, base catalyst, or metal chelate compound can be used as a reaction catalyst. As the acid, Bronsted acid such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid or the like, or organic acid such as acetic acid, formic acid, methanesulfonic acid, trifluoromethanesulfonic acid, paratoluenesulfonic acid, dibutyltin dilaurate, Examples thereof include Lewis acids such as dibutyltin diacetate, dibutyltin dioctate, triisopropoxyaluminum, tetrabutoxyzirconium, and tetrabutoxytitanate.
The amount of the curing accelerator used varies depending on the type of compound and the difference in the curing reactive site, but is generally preferably 0.1 to 15% by mass, more preferably based on the total solid content of the curable composition. 0.5-5 mass%.
As the polymerization initiator, those described below can be used.

[Polymer Compound (B)]
The light diffusion layer according to the present invention preferably contains a polymer compound other than the above (hereinafter also referred to as polymer compound (B)). The polymer compound (B) has already formed a polymer at the time of addition to the coating composition, and the viscosity adjustment of the coating composition mainly related to the dispersion stability (aggregation property, sedimentation speed) of the translucent particles, It is contained for the purpose of changing the aggregation behavior of the translucent particles by controlling the polarity of the residue in the drying process or reducing drying unevenness in the drying process.
Examples of the polymer compound (B) for this purpose include, for example, methyl methacrylate / methyl acrylate copolymer, methyl methacrylate / ethyl acrylate copolymer, methyl methacrylate / butyl acrylate copolymer, methyl methacrylate / (Meth) acrylic resins such as butyl methacrylate copolymer, methyl methacrylate / styrene copolymer, methyl methacrylate / methacrylic acid copolymer, and polymethyl methacrylate.
Examples thereof include cellulose resins such as cellulose triacetate, cellulose diacetate, cellulose acetate butyrate, hydroxypropyl cellulose, hydroxyethyl methacrylate, and hydroxyethyl cellulose.

  As a product of the polymer compound (B), for example, poly (methacrylic acid ester), poly (methyl methacrylate / ethyl acrylate) molecular weight 101,000, poly (methyl methacrylate / butyl methacrylate) molecular weight 75,000 , Polymethyl methacrylate molecular weight 120,000, 15,000, 350,000, 996,000 (all manufactured by Sigma-Aldrich Japan), polybutyl methacrylate (molecular weight 300,000, manufactured by Kanto Chemical Co., Ltd.), Acripet MD, VH, MF, V (Mitsubishi Rayon Co., Ltd.), Sumipex LG21, LG, EX, MH (Sumitomo Chemical Co., Ltd.), Parapet GF, G, GH-S, HR-L, GR (Manufactured by Kuraray Co., Ltd.).

The polymer compound (B) is preferably 3% by mass to 40% by mass with respect to the total binder contained in the light diffusion layer, from the viewpoint of expressing the viscosity increasing effect of the coating composition and maintaining the film strength of the containing layer. Preferably, it is contained in a range of 5 to 30% by mass, more preferably 8 to 25% by mass. 3 mass% or more is preferable at the point of the viscosity increase effect of a coating composition, and 40 mass% or less is preferable at the point of the film | membrane intensity | strength maintenance of a content layer.
The molecular weight of the polymer compound (B) is preferably from 30,000 to 400,000 in terms of mass average, more preferably from 50,000 to 300,000, and even more preferably from 50,000 to 200,000. When the molecular weight is within this range, the effect of increasing the viscosity of the coating composition is sufficiently exhibited, the dissolution time is short, and there are few insolubles.
In addition, the viscosity of the coating composition containing the polymer compound (B) is preferably in the range of 4 mPa · s to 30 mPa · s, mainly from the viewpoint of antiglare property control and coating surface shape, and 6 mPa · s to 20 mPa · s. Is more preferable, and 7 mPa · s to 15 mPa · s is most preferable.

[Polymerization initiator]
Polymerization of the monomer having an ethylenically unsaturated group can be carried out by irradiation with ionizing radiation or heating in the presence of a photo radical initiator or a thermal radical initiator.
Accordingly, a cured composition containing a monomer having an ethylenically unsaturated group, a photo radical initiator or a thermal radical initiator, mat particles and an inorganic filler, and other additives is prepared, and the cured composition is placed on a transparent support. After coating, the film is cured by ionizing radiation or a polymerization reaction by heat to form an optical film. It is also preferable to perform ionizing radiation curing and thermal curing together.

Photo radical polymerization initiators include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds , Fluoroamine compounds, aromatic sulfoniums, lophine dimers, onium salts, borate salts, active esters, active halogens, inorganic complexes, coumarins and the like.
Examples of acetophenones include 2,2-dimethoxyacetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxy-dimethylphenylketone, 1-hydroxy-dimethyl-p-isopropylphenylketone, 1-hydroxy Cyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-morpholinopropiophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone, 4-phenoxydichloroacetophenone, 4-t- Butyl-dichloroacetophenone.
Examples of benzoins include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl dimethyl ketal, benzoin benzene sulfonate, benzoin toluene sulfonate, benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether It is.
Examples of benzophenones include benzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 2,4-dichlorobenzophenone, 4,4-dichlorobenzophenone and p-chlorobenzophenone, 4,4'-dimethylaminobenzophenone (Michler's ketone), 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone and the like.

Examples of phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide.
Examples of active esters include 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], sulfonic acid esters, cyclic active ester compounds, and the like.
Examples of the onium salts include aromatic diazonium salts, aromatic iodonium salts, and aromatic sulfonium salts.
Examples of borate salts include ion complexes with cationic dyes.
Examples of active halogens are S-triazine and oxathiazole compounds. 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) ) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-styrylphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (3-Br-4-di ( Ethyl acetate) amino) phenyl) -4,6-bis (trichloromethyl) -s-triazine, 2-trihalomethyl-5- (p-methoxyphenyl) -1,3,4-oxadiazole.
Examples of inorganic complexes include bis (η ⁵ -2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium.
Examples of coumarins include 3-ketocoumarin.
These initiators may be used alone or in combination.

“Latest UV Curing Technology”, Technical Information Association, 1991, p. Various examples are also described in 159 and are useful in the present invention.
Commercially available photocleavable photoradical polymerization initiators include Irgacure (651, 184, 819, 907, 1870 (CGI-403 / Irg184 = 7/3 mixed initiator, 500) manufactured by Ciba Specialty Chemicals Co., Ltd. , 369, 1173, 2959, 4265, 4263), OXE, etc., Kayacure (DETX-S, BP-100, BDMK, CTX, BMS, 2-EAQ, ABQ, CPTX, EPD, manufactured by Nippon Kayaku Co., Ltd., Preferred examples include Esacure (KIP100F, KB1, EB3, BP, X33, KT046, KT37, KIP150, TZT) manufactured by Sartomer, etc.
It is preferable to use a photoinitiator in the range of 0.1-15 mass parts with respect to 100 mass parts of polyfunctional monomers, More preferably, it is the range of 1-10 mass parts.
In addition to the photopolymerization initiator, a photosensitizer may be used. Specific examples of the photosensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, Michler's ketone and thioxanthone.
Furthermore, one or more auxiliary agents such as an azide compound, a thiourea compound, and a mercapto compound may be used in combination.

Examples of commercially available photosensitizers include Kayacure (DMBI, EPA) manufactured by Nippon Kayaku Co., Ltd.
As the thermal radical initiator, organic or inorganic peroxides, organic azo, diazo compounds, and the like can be used.
Specifically, benzoyl peroxide, halogen benzoyl peroxide, lauroyl peroxide, acetyl peroxide, dibutyl peroxide, cumene hydroperoxide, butyl hydroperoxide as organic peroxides, hydrogen peroxide, peroxides as inorganic peroxides. Diazo compounds such as ammonium sulfate, potassium persulfate and the like, 2,2′-azobis (isobutyronitrile), 2,2′-azobis (propionitrile), 1,1′-azobis (cyclohexanecarbonitrile), etc. And diazoaminobenzene, p-nitrobenzenediazonium and the like.

When a polymer having a polyether as a main chain is used as a binder, a ring-opening polymer of a polyfunctional epoxy compound is preferable. The ring-opening polymerization of the polyfunctional epoxy compound can be performed by irradiation with ionizing radiation or heating in the presence of a photoacid generator or a thermal acid generator.
Therefore, a coating solution containing a polyfunctional epoxy compound, a photoacid generator or a thermal acid generator, translucent particles and an inorganic filler is prepared, and the coating solution is applied onto a transparent support and then polymerized by ionizing radiation or heat. It can be cured by reaction to form an optical film.

[Organic solvent]
The coating composition for a light diffusion layer used in the present invention contains at least two kinds of organic solvents.
The at least two organic solvents preferably have at least one combination in which the difference in I / O value between the organic solvents is 0.25 or more. At least two kinds of organic solvents having a difference in I / O value have relatively hydrophilic and hydrophobic properties, respectively. Generally, hydrophilic organic solvents are mainly used for surface irregularities of layers that affect antiglare properties. The hydrophobic organic solvent has the effect of enhancing the cohesiveness of the particles involved, and the effect of increasing the dissolution stability of the monomers and the dispersion stability of the resin particles.
The at least two organic solvents preferably have a difference in I / O value between the organic solvents of 0.25 or more, more preferably 0.4 or more, and even more preferably 0.6 or more. . It is preferable to have at least one combination of organic solvents having an I / O value difference within this range.
For example, the relatively hydrophilic organic solvent preferably has an I / O value of 1.0 or more. (In the present invention, for the sake of distinction, such an organic solvent is referred to as a hydrophilic organic solvent.)
The I / O value of the hydrophilic organic solvent is preferably 1.0 or more, more preferably 1.5 or more, and further preferably 2.0 or more. The upper limit is not particularly limited, but is preferably about 8.
The hydrophilic organic solvent is preferably contained in an amount of 3% by mass to 30% by mass with respect to the total organic solvent in the coating composition from the viewpoint of being effective for aggregation and not accelerating the aggregation too much. The content is more preferably 20% by mass, and most preferably 7% by mass to 15% by mass.

Specific examples of the hydrophilic organic solvent include, for example, ketones, acetone, diacetone alcohol, acetonyl acetone, etc.
In the alcohol system, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, 1-pentanol, isoamyl alcohol, etc.
In the ester system, methyl acetate, ethyl acetate, methyl propionate, methyl acetoacetate, ethyl acetoacetate, nbutyl lactate, isobutyl lactate, diethyl oxalate, etc.
For polyhydric alcohols and their derivatives, ethylene glycol, ethylene glycol monoacetate, diethylene glycol, propylene glycol, dipropylene glycol, butanediol, ethylene glycol diacetate, diethylene glycol monomethyl ether, propylene glycol monoacetate, dipropylene glycol, trimethylene glycol Hexylene glycol, 1,5-pentadiol, 1,2,6-hexanetriol, etc.
In the fatty acid system, formic acid, acetic acid, propionic acid, entangling acid, isoentangled acid, valeric acid, isovaleric acid, lactic acid, etc.
In the nitrogen compound system, formamide, acetamide, acetonitrile, etc.
Examples of the sulfur compound system include dimethyl sulfoxide.
Examples of other solvents include ethylene carbonate.

Among the hydrophilic organic solvents, the boiling point is preferably relatively high, the boiling point is preferably 160 ° C to 250 ° C, more preferably 170 ° C to 240 ° C, and further preferably 180 ° C to 230 ° C.
In the present invention, these particularly preferred hydrophilic solvents are referred to as hydrophilic high-boiling solvents.
Particularly preferred hydrophilic solvents are hydrophilic high-boiling solvents, among the specific examples of the hydrophilic organic solvent, those having a hydroxyl group in their molecular structure (preferably those having two or more hydroxyl groups), sulfur atoms Alternatively, those having a nitrogen atom or fatty acids are preferred, and specifically, ethylene glycol, propylene glycol, butanediol, ethylene glycol monoacetate, dimethyl sulfoxide, 1,2,6-hexanetriol, and lactic acid are preferred, and ethylene glycol , Propylene glycol, butanediol, and ethylene glycol monoacetate are more preferable.
Two or more hydrophilic high-boiling organic solvents may be used in combination.

  The hydrophilic high boiling point organic solvent may be contained in a trace amount as a residual solvent in either the light diffusion layer or the optical film. A trace amount of residual solvent has an effect of delaying whitening of the film due to precipitation of additives. Residual solvent can be quantified by gas chromatography.

Moreover, the coating composition which forms a light-diffusion layer contains the relatively hydrophobic organic solvent other than the said hydrophilic organic solvent. Such a hydrophobic organic solvent preferably has an I / O value of less than 1.0. (In the present invention, these relatively hydrophobic organic solvents are referred to as hydrophobic organic solvents for distinction.)
The I / O value of the hydrophobic organic solvent is preferably less than 1.0 to 0, more preferably 0.9 to 0, and still more preferably 0.8 to 0.
The boiling point of the hydrophobic organic solvent is preferably less than 160 ° C to 30 ° C, more preferably 150 ° C to 40 ° C, and further preferably 140 ° C to 50 ° C.
The hydrophobic organic solvent has good solubility of the monomer, the above-described polymer compound (B), other additives, and the like, and can maintain good dispersion stability of the resin particles and the like. Such an organic solvent is preferably vaporized at the initial stage of the drying step.

As such a hydrophobic organic solvent, an organic solvent widely used in the industry as a solvent can be used, and specific examples thereof include, for example, ketone-based solvents such as methyl isobutyl ketone, methyl ethyl ketone, diethyl ketone, and cyclohexanone.
In the alcohol system, n-hexanol, methyl amyl alcohol, etc.
In ether and acetal systems, 1,4 dioxane, tetrahydrofuran, 2-methylfuran, tetrahydropyran, diethyl acetal, etc.
In the ester system, n-propyl acetate, isopropyl acetate, isobutyl acetate, n-butyl acetate, isoamyl acetate, n-amyl acetate, ethyl propionate, methyl butyrate, ethyl butyrate, etc.
For hydrocarbons, hexane, heptane, octane, isooctane, ligroin, cyclohexane, methylcyclohexane, toluene, xylene, ethylbenzene, styrene, divinylbenzene, etc.
For halogenated hydrocarbons, carbon tetrachloride, chloroform, methylene chloride, ethylene chloride, 1,1,1-trichloroethane, 1,1,2-trichloroethane, trichloroethylene, tetrachloroethylene, 1,1,1,2 -Tetrachloroethane is preferred.
Among these, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, toluene, xylene and the like are particularly preferable.
Two or more hydrophobic organic solvents may be used.

The hydrophobic organic solvent is preferably contained in the total organic solvent in the coating composition in an amount of 70% by mass to 97% by mass, more preferably 80% by mass to 95% by mass, and more preferably 85% by mass to 93% by mass. Most preferably.
As the organic solvent of the coating composition according to the present invention, it is preferable to use a mixture of a hydrophilic organic solvent and a hydrophobic organic solvent as appropriate, and use two or more kinds.

[Translucent resin particles]
The light diffusion layer contains at least two kinds of translucent resin particles. Each of the two kinds of translucent resin particles preferably has an average particle size larger than that of the fine inorganic filler particles described later, and the average particle size of each species is preferably 0.5 μm to 25 μm, preferably 1 μm to It is more preferably 20 μm, and particularly preferably 3 μm to 7 μm. The average particle size of the first resin particle type having the largest average particle size among at least two types of particles is preferably 2 μm to 20 μm, and more preferably 3 μm to 15 μm.
The average particle size of the second particle type having the largest average particle size after the first resin particle type having the largest average particle size among the at least two types of particles is the first particle size in the present invention. It is 30% to 90% with respect to the average particle diameter of the particles, preferably 40% to 85%, and more preferably 40% to 80%.
When the third and subsequent particle types are used, the average particle size is preferably in the range of the preferable average particle size of the second particle type.

In the present invention, the relationship between the particle diameter of the translucent resin particles and the film thickness of the light diffusing layer is such that the average particle diameter of the particle type having the maximum average particle diameter is 20 times the thickness after curing of the light diffusing layer. % To 90%, preferably 30% to 85%, and most preferably 35% to 80%. When the average particle size is within this range, the screen is excellent in blackness and anti-glare properties.
In the present invention, when the average particle size of the second particle type is set between 40% and 85% with respect to the average particle size of the first particle, the first resin particle type having the largest average particle size Is preferably 30% to 85%, and most preferably 35% to 80% of the thickness of the light diffusion layer after curing. Furthermore, when the average particle size of the second particle type is set between 40% and 80% with respect to the average particle size of the first particle, the average particle size of the first resin particle type having the largest average particle size The diameter is preferably 35% to 80% of the thickness of the light diffusion layer after curing. By setting in this way, the screen is further excellent in blackness and anti-glare properties.

These uses are effective for increasing the feeling of blackening on the screen while scattering and weakening the external light reflected on the display surface and expanding the viewing angle (particularly the downward viewing angle) of the liquid crystal display device. If the average particle size is in the above range, the feeling of roughness does not occur.
The difference in refractive index between the translucent resin particles and the binder resin is preferably 0 to 0.30 in each average refractive index from the viewpoint that the film does not become cloudy and obtains a sufficient light diffusion effect. Particularly preferred is 0.03 to 0.20.
From the same viewpoint, the preferable amount of the translucent resin particles added to the light diffusion layer is determined. The total content of the light-transmitting resin particles in the preferred layer is 3% by mass to 40% by mass, and particularly preferably 5% by mass to 25% by mass in the total solid content of the light diffusion layer.
The coating amount of the translucent particles is preferably 10 mg / m ^{2 to} 10,000 mg / m ² , more preferably 50 mg / m ^{2 to} 4000 mg / m ² , most preferably 100 mg / m ^{2 in} terms of the amount of particles in the formed light diffusion layer. It is contained in the light diffusion layer so as to be m ^{2 to} 1500 mg / m ² .
The particle size distribution of the particles according to the present invention is measured by a light diffraction method. As the average particle size, the particle size corresponding to 50% by volume of the volume integration curve was used.

  The particle size distribution of the translucent resin particles according to the present invention is the degree of dispersion in terms of the efficient use of particles contributing to the formation of surface irregularities in the total number of plural types of translucent resin particles contained in the light diffusion layer. The value when (V) is expressed by the following mathematical formula A is preferably V = 0.6 to 1.0, and more preferably 0.7 to 0.9.

Formula A
V = (90% volume cumulative particle size−10% volume cumulative particle size) / 50% volume cumulative particle size

The particle size distribution was determined from the diameter of 500 particles photographed using a scanning electron microscope with the powder particles fixed to an adhesive tape. The measured particle diameter was divided into 0.2 μm from the smallest one to determine the frequency of each class, and the volume integrated particle diameter was determined from the integrated volume.
Optical diffraction particle size distribution measuring device 0.6 or more is preferable from the viewpoint of the effect of improving blackening, and 1.0 or less is preferable from the viewpoint that the roughness is small and no increase is required to exhibit the blackening effect.

As the translucent resin particles, translucent resin particles having two or more different average particle diameters are used in combination. The refractive index between two or more kinds of resin particles may be different or the same.
Specific examples of the translucent resin particles include polymethyl (meth) acrylate particles, crosslinked polymethyl (meth) acrylate particles, crosslinked methyl (meth) acrylate-styrene copolymer particles, and crosslinked methyl (meth) acrylate-acrylic acid copolymer. Preferred examples include resin particles such as polymer particles, crosslinked methyl methacrylate-acrylate copolymer particles, crosslinked polystyrene particles, melamine resin particles, benzoguanamine resin particles, polycarbonate particles, and polyvinyl chloride particles. Of these, crosslinked styrene particles, crosslinked polymethyl (meth) acrylate particles, and crosslinked methyl (meth) acrylate-styrene copolymer particles are preferable.
Of the translucent resin particles used in at least two kinds, the individual particle size distribution is preferably monodisperse particles in view of haze value, controllability of diffusibility, and uniformity of the coated surface. For example, when a particle having a particle size of 20% or more than the average particle size in a certain type of particle is defined as a coarse particle, the proportion of the coarse particle is preferably 1% or less of the total number of particles, more preferably 0. .1% or less, more preferably 0.01% or less. Particles having such a particle size distribution are obtained by classification after a normal synthesis reaction, and particles having a more preferable distribution can be obtained by increasing the number of classifications or increasing the degree of classification.

  Examples of the method for producing the translucent resin particles include a suspension polymerization method, an emulsion polymerization method, a soap-free emulsion polymerization method, a dispersion polymerization method, a seed polymerization method, and the like, and any method may be used. These production methods are described in, for example, “Experimental Methods for Polymer Synthesis” (Takayuki Otsu and Masaaki Kinoshita, Chemical Dojinsha), pages 130 and 146 to 147, “Synthetic Polymers”, Vol. 246-290, 3rd volume, p. 1 to 108, etc., and Japanese Patent Nos. 2543503, 3508304, 2746275, 3521560, 3580320, and Japanese Patent Laid-Open No. 10-1561. Reference can be made to methods described in JP-A No. 7-2908, JP-A No. 5-297506, JP-A No. 2002-145919, and the like.

The average value of the I / O value of the translucent resin particles is preferably 0 to 1.5, more preferably 0.05 to 1.3. The method for calculating the average I / O value of the translucent resin particles is as described above.
In addition, as described above, the ionizing radiation curable monomer according to the present invention is the difference between the average value of the translucent resin particles and the I / O value as the average value of the total monomers in order to easily control the antiglare property. Is 0.3 to 3.0, more preferably 0.5 to 2.5.

[Filler additive material]
In order to increase the refractive index of the light diffusion layer, the light diffusion layer is oxidized with at least one metal selected from titanium, zirconium, aluminum, indium, zinc, tin, and antimony in addition to the above-described translucent resin particles. It is preferable that a very fine inorganic filler is contained which has an average primary particle size of 0.2 μm or less, preferably 0.1 μm or less, more preferably 0.06 μm or less.
Conversely, in a light diffusion layer using translucent resin particles having a high refractive index, the refractive index of the binder must be lowered in order to increase the difference in refractive index from the particles. For this purpose, it is also preferable to use silica fine particles and hollow silica fine particles. The preferred particle size is the same as that of the above-mentioned high refractive index fine inorganic filler.
Specific examples of the fine inorganic filler used for the light diffusion layer include TiO ₂ , ZrO ₂ , Al ₂ O ₃ , In ₂ O ₃ , ZnO, SnO ₂ , Sb ₂ O ₃ , ITO and SiO ₂ . TiO ₂ and ZrO ₂ are particularly preferable in terms of increasing the refractive index. The surface of the inorganic filler is preferably subjected to a silane coupling treatment or a titanium coupling treatment, and a surface treatment agent having a functional group capable of reacting with a binder species on the filler surface is preferably used.
The addition amount of these fine inorganic fillers is preferably 10 to 90% of the total mass of the light diffusion layer, more preferably 20 to 80%, and particularly preferably 30 to 75%.
The fine inorganic filler does not scatter because the particle size is sufficiently shorter than the wavelength of light, and the dispersion in which the filler is dispersed in the binder polymer has the property of an optically uniform substance.

[Fluorine surface conditioner]
The light diffusing layer used in the present invention is not limited to the surface property improver of either fluorine or silicone, or both, in order to ensure surface uniformity such as coating unevenness, drying unevenness, and point defects. It is preferably contained in the coating composition for forming the diffusion layer. In particular, a fluorine-based surface conditioner is preferably used because an effect of improving surface defects such as coating unevenness, drying unevenness, and point defects of the optical film of the present invention appears with a smaller addition amount.
The purpose is to increase productivity by giving high-speed coating suitability while improving the surface uniformity.

  Preferable examples of the fluorine-based planarity improver include fluoroaliphatic group-containing copolymers (sometimes abbreviated as “fluorine polymer”), and the fluorine polymer is a monomer of the following (i): An acrylic resin, a methacrylic resin, and a vinyl monomer copolymerizable therewith, characterized by containing a repeating unit corresponding to Are useful.

(I) Fluoroaliphatic group-containing monomer represented by the following general formula

In the general formula A, R ¹¹ represents a hydrogen atom or a methyl group, X represents an oxygen atom, a sulfur atom or —N (R ¹² ) —, m is an integer of 1-6, and n is an integer of 2-4. To express. R ¹² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, specifically a methyl group, an ethyl group, a propyl group, or a butyl group, preferably a hydrogen atom or a methyl group. X is preferably an oxygen atom.

(Ii) a monomer represented by the following general formula (b) copolymerizable with (i) above

In the general formula B, R ¹³ represents a hydrogen atom or a methyl group, Y represents an oxygen atom, a sulfur atom or —N (R ¹⁵ ) —, R ¹⁵ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, specifically Specifically, it represents a methyl group, an ethyl group, a propyl group, or a butyl group, preferably a hydrogen atom or a methyl group. Y is an oxygen atom, -N (H) -, and -N (CH ₃₎ - are preferred.
R ¹⁴ represents a linear, branched or cyclic alkyl group having 4 to 20 carbon atoms which may have a substituent. Examples of the substituent for the alkyl group of R ¹⁴ include a hydroxyl group, an alkylcarbonyl group, an arylcarbonyl group, a carboxyl group, an alkyl ether group, an aryl ether group, a halogen atom such as a fluorine atom, a chlorine atom, and a bromine atom, a nitro group, and a cyano group. , Amino groups and the like, but not limited thereto. Examples of the linear, branched or cyclic alkyl group having 4 to 20 carbon atoms include a butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group and undecyl group which may be linear or branched. , Dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, octadecyl group, eicosanyl group, etc., and monocyclic cycloalkyl groups such as cyclohexyl group, cycloheptyl group and bicycloheptyl group, bicyclodecyl group, tricycloundecyl group, A polycyclic cycloalkyl group such as a tetracyclododecyl group, an adamantyl group, a norbornyl group, a tetracyclodecyl group, or the like is preferably used.

The amount of the fluoroaliphatic group-containing monomer represented by the general formula (a) used in the fluoropolymer used in the present invention is 10 mol% or more based on each monomer of the fluoropolymer, preferably Is 15 to 70 mol%, more preferably in the range of 20 to 60 mol%.
The preferred weight average molecular weight of the fluoropolymer is preferably 3000 to 100,000, more preferably 5,000 to 80,000.
Furthermore, the preferable addition amount of a fluorine-type polymer is the range of 0.001-5 mass% with respect to a coating liquid, Preferably it is the range of 0.005-3 mass%, More preferably, it is 0.01-1. It is the range of mass%. If the addition amount of the fluorine-based polymer is less than 0.001% by mass, the effect is insufficient, and if it exceeds 5% by mass, the coating film may not be sufficiently dried or the performance as a coating film (for example, reflectance) Adversely affect the scratch resistance).

  Examples of the specific structure of the fluoropolymer composed of the fluoroaliphatic group-containing monomer represented by the general formula (i) are shown below, but this is not restrictive. In addition, the number in a formula shows the molar ratio of each monomer component. Mw represents a mass average molecular weight.

The surface energy of the light diffusion layer is preferably effective to ^{20mN · m -1 ~50mN · m -1} , more preferably controlled to ^{30mN · m -1 ~40mN · m -1} . In order to realize the surface energy as described above, F / C, which is a ratio of a peak derived from a fluorine atom and a peak derived from a carbon atom, measured by X-ray photoelectron spectroscopy is usually 0.1 to 1.5. .

  When a further upper layer is applied on the light diffusion layer, it is preferable to select a fluorine-based polymer that can be extracted by a solvent for forming the upper layer. Examples of such a material include a fluoro fat represented by the following general formula C It is a copolymer of an acrylic resin, a methacrylic resin, and a vinyl monomer copolymerizable therewith, which contain a repeating unit corresponding to a group-containing monomer.

(Iii) A fluoroaliphatic group-containing monomer represented by the following general formula C

In the general formula C, R ²¹ represents a hydrogen atom, a halogen atom or a methyl group, and more preferably a hydrogen atom or a methyl group. X ² represents an oxygen atom, a sulfur atom or —N (R ²² ) —, more preferably an oxygen atom or —N (R ²² ) —, and still more preferably an oxygen atom. m is an integer from 1 to 6 (more preferably from 1 to 3, more preferably 1), and n is an integer from 1 to 18 (more preferably from 4 to 12, and even more preferably from 6 to 8). Represents. R ²² represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms which may have a substituent, more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and further preferably a hydrogen atom or a methyl group. X is preferably an oxygen atom.
In addition, two or more kinds of fluoroaliphatic group-containing monomers represented by the general formula C may be contained in the fluorine-based polymer as constituent components.

(Iv) a monomer represented by the following general formula D copolymerizable with the above (iii)

In the general formula D, R ²³ represents a hydrogen atom, a halogen atom or a methyl group, more preferably a hydrogen atom or a methyl group. Y ² represents an oxygen atom, a sulfur atom or —N (R ²⁵ ) —, more preferably an oxygen atom or —N (R ²⁵ ) —, and still more preferably an oxygen atom. R ²⁵ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
R ²⁴ is an optionally substituted linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, an alkyl group containing a poly (alkyleneoxy) group, and an optionally substituted aromatic group. (For example, a phenyl group or a naphthyl group). A linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms or an aromatic group having 6 to 18 carbon atoms is preferable.

  Hereinafter, examples of specific structures of fluoropolymers containing a repeating unit corresponding to the fluoroaliphatic group-containing monomer represented by formula (c) are shown, but the present invention is not limited thereto. In addition, the number in a formula shows the molar ratio of each monomer component. Mw represents a mass average molecular weight.

  Further, if the surface energy is prevented from being lowered when the low refractive index layer is overcoated on the light diffusion layer, the deterioration of the antireflection performance can be prevented. The surface energy of the light diffusing layer before coating the low refractive index layer is controlled within the above range by preventing the surface free energy from decreasing by applying corona treatment, UV treatment, heat treatment, saponification treatment, solvent treatment, etc. after coating the light diffusing layer. can do.

  Moreover, you may add a thixotropic agent in the coating composition for forming a light-diffusion layer. Examples of the thixotropic agent include silica and mica of 0.1 μm or less. In general, the content of these additives is preferably about 1 to 10 parts by mass with respect to 100 parts by mass of the ultraviolet curable resin.

<Low refractive index layer>
[Low refractive index layer material]
The low refractive index layer usually contains fine particles and a binder for dispersing and fixing the fine particles. As the binder, the binder described in the light diffusion layer can be used, but it is preferable to use a fluorine-containing polymer having a low refractive index or a fluorine-containing sol-gel material. The fluorine-containing polymer or fluorine-containing sol-gel is a material that has a dynamic friction coefficient of 0.03 to 0.30 on the surface of the low refractive index layer formed by crosslinking by heat or ionizing radiation and a contact angle of 85 to 120 ° with water. Is preferred.

The refractive index of the low refractive index layer is preferably 1.20 to 1.46, more preferably 1.25 to 1.46, and particularly preferably 1.30 to 1.46.
The thickness of the low refractive index layer is preferably 50 to 200 nm, and more preferably 70 to 100 nm. The haze of the low refractive index layer is preferably 3% or less, more preferably 2% or less, and most preferably 1% or less. The specific strength of the low refractive index layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher in a pencil hardness test under a 500 g load.
In order to improve the antifouling performance of the optical film, it is preferable that the contact angle of the surface with respect to water is 90 degrees or more. More preferably, it is 95 degrees or more, and particularly preferably 100 degrees or more.

  Further, the low refractive index layer preferably satisfies the following formula (I) from the viewpoint of reducing the reflectance.

Formula (I)
(M / 4) × 0.7 <n1 × d1 <(m / 4) × 1.3

In Formula (I), m is a positive odd number, n1 is the refractive index of the low refractive index layer, and d1 is the film thickness (nm) of the low refractive index layer. Further, λ is a wavelength and is a value in the range of 500 to 550 nm.
In addition, satisfy | filling said numerical formula (I) means that m (positive odd number, usually 1) which satisfy | fills numerical formula (I) exists in the said wavelength range.

[Fluoropolymer for low refractive index layer]
The polymer preferably used for the low refractive index layer used in the present invention will be described below.
Examples of the fluorine-containing vinyl monomer include fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, etc.), (meth) acrylic acid moieties or fully fluorinated alkyl ester derivatives (for example, biscoat 6FM (trade name) , Osaka Organic Chemical Co., Ltd.) and R-2020 (trade name, manufactured by Daikin Co., Ltd.), fully or partially fluorinated vinyl ethers, and the like. Preferred are perfluoroolefins, refractive index, solubility, and transparency. From the viewpoint of availability, hexafluoropropylene is particularly preferable. Increasing the composition ratio of these fluorinated vinyl monomers can lower the refractive index but lowers the film strength. In the present invention, it is preferable to introduce the fluorine-containing vinyl monomer so that the fluorine content of the polymer is 20 to 60% by mass, more preferably 25 to 55% by mass, and particularly preferably 30 to 50% by mass. This is the case.

Examples of the structural unit for imparting crosslinking reactivity mainly include units represented by the following (A), (B), and (C).
(A): a structural unit obtained by polymerization of a monomer having a self-crosslinkable functional group in the molecule in advance such as glycidyl (meth) acrylate and glycidyl vinyl ether,
(B): a monomer having a carboxyl group, a hydroxy group, an amino group, a sulfo group, etc. (for example, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether) , Maleic acid, crotonic acid, etc.)
(C): a group having a crosslinkable functional group separately from a group that reacts with the functional group of (A) or (B) in the molecule and a structural unit of (A) or (B) above. Examples of the structural unit to be obtained include (for example, a structural unit that can be synthesized by a technique such as allowing acrylic acid chloride to act on a hydroxyl group).

  In the constitutional unit (C), particularly in the present invention, the crosslinkable functional group is preferably a photopolymerizable group. Examples of the photopolymerizable group include (meth) acryloyl group, alkenyl group, cinnamoyl group, cinnamylideneacetyl group, benzalacetophenone group, styrylpyridine group, α-phenylmaleimide group, phenylazide group, sulfonylazide. Group, carbonyl azide group, diazo group, o-quinonediazide group, furylacryloyl group, coumarin group, pyrone group, anthracene group, benzophenone group, stilbene group, dithiocarbamate group, xanthate group, 1,2,3-thiadiazole group, cyclo A propene group, an azadioxabicyclo group, etc. can be mentioned, These may be not only 1 type but 2 or more types. Of these, a (meth) acryloyl group and a cinnamoyl group are preferable, and a (meth) acryloyl group is particularly preferable.

Specific methods for preparing the photopolymerizable group-containing copolymer include, but are not limited to, the following methods.
(1) A method of esterifying a crosslinkable functional group-containing copolymer containing a hydroxyl group by reacting (meth) acrylic acid chloride,
(2) A method of urethanizing a crosslinkable functional group-containing copolymer containing a hydroxyl group with a (meth) acrylic acid ester containing an isocyanate group,
(3) A method of esterifying by reacting (meth) acrylic acid with a crosslinkable functional group-containing copolymer containing an epoxy group,
(4) A method in which a crosslinkable functional group-containing copolymer containing a carboxyl group is esterified by reacting a containing (meth) acrylic acid ester containing an epoxy group.
The amount of the photopolymerizable group introduced can be arbitrarily adjusted. From the viewpoint of surface stability of the coating film, reduction of surface failure when coexisting with inorganic fine particles, and improvement of film strength, carboxyl group, hydroxyl group, etc. It is also preferable to leave a certain amount.

  In the copolymer useful for the present invention, in addition to the repeating unit derived from the above-mentioned fluorine-containing vinyl monomer and the repeating unit having a (meth) acryloyl group in the side chain, it contributes to adhesion to the substrate and Tg of the polymer (film hardness). And other vinyl monomers can be copolymerized as appropriate from various viewpoints such as solubility in a solvent, transparency, slipperiness, dust resistance and antifouling properties. A plurality of these vinyl monomers may be combined depending on the purpose, and are preferably introduced in the range of 0 to 65 mol% in the copolymer in total, and in the range of 0 to 40 mol%. More preferably, it is particularly preferably in the range of 0 to 30 mol%.

  The vinyl monomer unit that can be used in combination is not particularly limited. For example, olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic esters (methyl acrylate, methyl acrylate, ethyl acrylate, acrylic acid) 2-ethylhexyl, 2-hydroxyethyl acrylate), methacrylic acid esters (methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-hydroxyethyl methacrylate, etc.), styrene derivatives (styrene, p-hydroxymethylstyrene, p -Methoxystyrene, etc.), vinyl ethers (methyl vinyl ether, ethyl vinyl ether, cyclohexyl vinyl ether, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, etc.), vinyl esters (vinyl acetate) Vinyl propionate, vinyl cinnamate, etc.), unsaturated carboxylic acids (acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, etc.), acrylamides (N, N-dimethylacrylamide, N-tert-butylacrylamide, N -Cyclohexyl acrylamide, etc.), methacrylamides (N, N-dimethylmethacrylamide), acrylonitrile and the like.

  The fluorine-containing polymer particularly useful in the present invention is a random copolymer of perfluoroolefin and vinyl ethers or vinyl esters. In particular, it preferably has a group capable of undergoing a crosslinking reaction alone (a radical reactive group such as a (meth) acryloyl group, a ring-opening polymerizable group such as an epoxy group or an oxetanyl group). These crosslinkable group-containing polymerized units preferably occupy 5 to 70 mol% of the total polymerized units of the polymer, particularly preferably 30 to 60 mol%. Regarding preferred polymers, JP-A-2002-243907, JP-A-2002-372601, JP-A-2003-26732, JP-A-2003-222702, JP-A-2003-294911, JP-A-2003-329804, JP-A-2004. -4444 and JP, 2004-45462, A can be mentioned.

  Moreover, it is preferable that the polysiloxane structure is introduce | transduced in the fluorine-containing polymer used for this invention in order to provide antifouling property. There is no limitation on the method of introducing the polysiloxane structure, but for example, as described in JP-A-6-93100, JP-A-11-189621, JP-A-11-228631 and JP-A-2000-313709, the initiation of silicone macroazo A method of introducing a polysiloxane block copolymer component using an agent, and a method of introducing a polysiloxane graft copolymer component using a silicone macromer as described in JP-A-2-251555 and JP-A-2-308806. preferable. Particularly preferred compounds include the polymers of Examples 1, 2, and 3 of JP-A-11-189621, and the copolymers A-2 and A-3 of JP-A-2-251555. These polysiloxane components are preferably 0.5 to 10% by mass, particularly preferably 1 to 5% by mass in the polymer.

  A preferred form of the fluorine-containing polymer for the low refractive index layer used in the present invention is a copolymer represented by the general formula 1.

In General Formula 1, L represents a linking group having 1 to 10 carbon atoms, more preferably a linking group having 1 to 6 carbon atoms, particularly preferably a linking group having 2 to 4 carbon atoms, It may have a branched structure, may have a ring structure, or may have a heteroatom selected from O, N and S.
Preferred examples include * — (CH ₂ ) ₂ —O — **, * — (CH ₂ ) ₂ —NH — **, * — (CH ₂ ) ₄ —O — **, * — (CH ₂ ). _{6 -O - **, * - (} CH 2) 2 -O- (CH 2) 2 -O - **, * - CONH- (CH 2) 3 -O - **, * -CH 2 CH (OH ) CH ₂ —O — **, * —CH ₂ CH ₂ OCONH (CH ₂ ) ₃ —O — ** (* represents the connecting site on the polymer main chain side, and ** represents the connecting on the (meth) acryloyl group side) Represents a part). b represents 0 or 1;

In General Formula 1, X ¹ represents a hydrogen atom or a methyl group. From the viewpoint of curing reactivity, a hydrogen atom is more preferable.
In the general formula 1, A represents a repeating unit derived from an arbitrary vinyl monomer, and is not particularly limited as long as it is a constituent component of a monomer copolymerizable with hexafluoropropylene. Tg (contributes to film hardness), solubility in solvents, transparency, slipperiness, dustproof / antifouling properties, etc., can be selected as appropriate. It may be configured.

  Preferred examples include methyl vinyl ether, ethyl vinyl ether, t-butyl vinyl ether, cyclohexyl vinyl ether, isopropyl vinyl ether, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, glycidyl vinyl ether, vinyl ethers such as allyl vinyl ether, vinyl acetate, vinyl propionate, butyric acid. (Meth) such as vinyl esters such as vinyl, methyl (meth) acrylate, ethyl (meth) acrylate, hydroxyethyl (meth) acrylate, glycidyl methacrylate, allyl (meth) acrylate, (meth) acryloyloxypropyltrimethoxysilane Acrylates, styrene, styrene derivatives such as p-hydroxymethylstyrene, crotonic acid, maleic acid, itaconic acid Can be mentioned unsaturated carboxylic acids and derivatives thereof, more preferably ether derivatives, vinyl ester derivatives, particularly preferably a vinyl ether derivative.

x1, y and z represent the mol% of each constituent component, and 30 ≦ x1 ≦ 60, 5 ≦ y ≦ 70, and 0 ≦ z ≦ 65 are preferable, and 35 ≦ x1 ≦ 55 and 30 ≦ y ≦ are more preferable. 60, 0 ≦ z ≦ 20, particularly preferably 40 ≦ x1 ≦ 55, 40 ≦ y ≦ 55, and 0 ≦ z ≦ 10. However, x1 + y + z = 100.
A particularly preferred form of the copolymer used in the present invention is General Formula 2.

In General Formula 2, X ¹ represents the same meaning as in General Formula 1, and the preferred range is also the same.
e represents an integer of 2 ≦ e ≦ 10, preferably 2 ≦ e ≦ 6, and particularly preferably 2 ≦ e ≦ 4.
B represents a unit of a repeating unit derived from an arbitrary vinyl monomer, and may be composed of a single composition or a plurality of compositions. As an example, what was demonstrated as an example of A in the said General formula 1 is applicable.
x1, y, z1 and z2 represent mol% of each repeating unit, and x1 and y preferably satisfy 30 ≦ x1 ≦ 60 and 5 ≦ y ≦ 70, respectively, more preferably 35 ≦ x1 ≦ 55. 30 ≦ y ≦ 60, particularly preferably 40 ≦ x1 ≦ 55 and 40 ≦ y ≦ 55. z1 and z2 preferably satisfy 0 ≦ z1 ≦ 65 and 0 ≦ z2 ≦ 65, more preferably 0 ≦ z1 ≦ 30 and 0 ≦ z2 ≦ 10, and 0 ≦ z1 ≦ 10, 0 It is particularly preferable that ≦ z2 ≦ 5. However, x1 + y + z1 + z2 = 100.
The copolymer represented by the general formula 1 or 2 is obtained, for example, by introducing a (meth) acryloyl group into a copolymer comprising a hexafluoropropylene component and a hydroxyalkyl vinyl ether component by any of the above-described methods. Can be synthesized. As the reprecipitation solvent used at this time, isopropanol, hexane, methanol and the like are preferable.
Preferable specific examples of the copolymer represented by the general formula 1 or 2 include those described in [0035] to [0047] of JP-A-2004-45462, and the method described in the publication Can be synthesized.

  The preferred molecular weight of the polymer that can be preferably used in the present invention is a mass average molecular weight of 5,000 or more, preferably 10,000 to 500,000, most preferably 15,000 to 200,000. By using polymers having different average molecular weights in combination, it is possible to improve the surface state of the coating film and the scratch resistance.

  As described in JP-A-10-25388 and JP-A-2000-17028, a curing agent having a polymerizable unsaturated group may be used in combination with the above polymer. Moreover, combined use with the compound which has a fluorine-containing polyfunctional polymerizable unsaturated group as described in Unexamined-Japanese-Patent No. 2002-145952 is also preferable. Examples of the compound having a polyfunctional polymerizable unsaturated group include the polyfunctional monomers described in the hard coat layer. These compounds are particularly preferred because they have a large combined effect for improving scratch resistance, particularly when a compound having a polymerizable unsaturated group is used in the polymer body.

  When the polymer itself does not have sufficient curability, necessary curability can be imparted by blending a crosslinkable compound. For example, when the polymer body contains a hydroxyl group, various amino compounds are preferably used as the curing agent. The amino compound used as the crosslinkable compound is, for example, a compound containing one or both of a hydroxyalkylamino group and an alkoxyalkylamino group in total, specifically, for example, a melamine compound, Examples include urea compounds, benzoguanamine compounds, glycoluril compounds, and the like.

  Melamine compounds are generally known as compounds having a skeleton in which a nitrogen atom is bonded to a triazine ring, and specific examples include melamine, alkylated melamine, methylol melamine, alkoxylated methyl melamine, and the like. However, it is preferable to have one or both of a methylol group and an alkoxylated methyl group in one molecule in total. Specifically, methylolated melamine, alkoxylated methylmelamine, or a derivative thereof obtained by reacting melamine and formaldehyde under basic conditions is preferable, and good storage stability is obtained particularly for the curable resin composition. Alkoxylated methyl melamine is preferable in that it can be obtained and good reactivity can be obtained. There are no particular restrictions on the methylolated melamine and the alkoxylated methylmelamine used as the crosslinkable compound. For example, the methylolated melamine and the alkoxylated methylmelamine can be obtained by the method described in the document “Plastic Materials Course [8] Urea Melamine Resin” (Nikkan Kogyo Shimbun). Various resinous materials can be used.

  In addition to urea, examples of the urea compound include polymethylolated urea, alkoxylated methylurea which is a derivative thereof, methylolated uron having a uron ring, and alkoxylated methyluron. And also about compounds, such as a urea derivative, the use of the various resinous materials described in said literature is possible.

In the low refractive index layer used in the present invention, a compound that generates radicals or acids upon irradiation with ionizing radiation or heat can be used.
As the photo radical initiator and the thermal radical initiator, the compounds described in the page of the light diffusion layer can be used.

[Thermal acid generator]
Specific examples of the thermal acid generator include various aliphatic sulfonic acids and salts thereof, various aliphatic carboxylic acids and salts thereof such as citric acid, acetic acid and maleic acid, and various aromatic carboxylic acids such as benzoic acid and phthalic acid. Examples thereof include acids and salts thereof, alkylbenzenesulfonic acids and ammonium salts thereof, amine salts, various metal salts, phosphoric acid and phosphoric acid esters of organic acids, and the like.
Examples of commercially available materials include catalyst 4040, catalyst 4050, catalyst 600, catalyst 602, catalyst 500, catalyst 296-9, and more made by Nippon Cytec Industries, Inc., and NACURE series 155, 1051, 5076, 4054J and its block type NACURE series 2500, 5225, X49-110, 3525, 4167 or more manufactured by King Corporation, and the like.
The use ratio of the thermal acid generator is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the binder. When the addition amount is within this range, the storage stability of the binder is good and the scratch resistance of the coating film is also good.

[Photosensitive acid generator]
Examples of the photosensitive acid generator include (1) various onium salts such as iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, ammonium salts, pyridinium salts; (2) β-ketoesters, β-sulfonylsulfones and these. sulfone compounds such as α-diazo compounds; (3) sulfonic acid esters such as alkyl sulfonic acid esters, haloalkyl sulfonic acid esters, aryl sulfonic acid esters, and imino sulfonates; (4) sulfonimide compounds; and (5) diazomethane compounds. Can be mentioned. The use ratio of the photosensitive acid generator is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the binder.

  The cured composition for a low refractive index layer preferably contains (A) the above-mentioned fluoropolymer, (B) inorganic fine particles, and (C) an organosilane compound described later.

[Inorganic fine particles for low refractive index layer]
As the low refractive index layer, it is also preferable to use a layer formed by using inorganic or organic fine particles and forming micro voids between or within the fine particles. The average particle diameter of the fine particles is preferably from 0.5 to 200 mm, more preferably from 1 to 100 nm, further preferably from 3 to 70 nm, and most preferably from 5 to 40 nm. The particle diameter of the fine particles is preferably as uniform (monodispersed) as possible.

  The inorganic fine particles are preferably amorphous. The inorganic fine particles are preferably made of a metal oxide, nitride, sulfide or halide, more preferably a metal oxide or metal halide, and most preferably a metal oxide or metal fluoride. . As metal atoms, Na, K, Mg, Ca, Ba, Al, Zn, Fe, Cu, Ti, Sn, In, W, Y, Sb, Mn, Ga, V, Nb, Ta, Ag, Si, B Bi, Mo, Ce, Cd, Be, Pb and Ni are preferred, and Mg, Ca, B and Si are more preferred. An inorganic compound containing two kinds of metals may be used. A particularly preferred inorganic compound is silicon dioxide, ie silica.

The microvoids in the inorganic fine particles can be formed, for example, by crosslinking silica molecules forming the particles. Crosslinking silica molecules reduces the volume and makes the particles porous. (Porous) inorganic fine particles having microvoids are described in the sol-gel method (described in JP-A Nos. 53-112732 and 57-9051) or the precipitation method (APPLIED OPTICS, 27, page 3356 (1988)). ) Can be directly synthesized as a dispersion.
Further, the powder obtained by the drying / precipitation method can be mechanically pulverized to obtain a dispersion. Commercially available porous inorganic fine particles (for example, silicon dioxide sol) may be used. The inorganic fine particles having microvoids are preferably used in a state of being dispersed in a suitable medium in order to form a low refractive index layer. As the dispersion medium, water, alcohol (eg, methanol, ethanol, isopropyl alcohol) and ketone (eg, methyl ethyl ketone, methyl isobutyl ketone) are preferable.
Microvoids between particles can be formed by stacking at least two fine particles.

  The low refractive index layer preferably contains a binder in an amount of 5 to 50% by weight. The binder has a function of adhering fine particles and maintaining the structure of the low refractive index layer including voids. The usage-amount of a binder is adjusted so that the intensity | strength of a low refractive index layer can be maintained, without filling a space | gap.

  The fine particles (particularly inorganic fine particles) are preferably subjected to a surface treatment to improve the affinity with the binder. The surface treatment can be classified into physical surface treatment such as plasma discharge treatment and corona discharge treatment, and chemical surface treatment using a coupling agent. It is preferable to carry out only chemical surface treatment or a combination of physical surface treatment and chemical surface treatment. As the coupling agent, an organoalkoxy metal compound (eg, titanium coupling agent, silane coupling agent) is preferably used. When the fine particles are made of silicon dioxide, surface treatment with a silane coupling agent can be carried out particularly effectively. The surface treatment with the coupling agent can be carried out by adding the coupling agent to the fine particle dispersion and leaving the dispersion at a temperature from room temperature to 60 ° C. for several hours to 10 days. In order to accelerate the surface treatment reaction, an inorganic acid, an organic acid, or a salt thereof (eg, metal salt, ammonium salt) may be added to the dispersion.

It is also preferable to form a shell with a polymer on the surface of the fine particles subjected to the surface treatment.
The polymer forming the shell is preferably a polymer having a saturated hydrocarbon as the main chain. A polymer containing a fluorine atom in the main chain or side chain is preferred, and a polymer containing a fluorine atom in the side chain is more preferred. Polyacrylic acid esters or polymethacrylic acid esters are preferred, and esters of fluorine-substituted alcohols with polyacrylic acid or polymethacrylic acid are most preferred.

The amount of the inorganic fine particles is preferably ^{1mg / m 2 ~100mg / m 2} , more preferably ^{5mg / m 2 ~80mg / m 2} , more preferably from ^{10mg / m 2 ~60mg / m 2} . If the amount is too small, the effect of improving the scratch resistance is reduced. If the amount is too large, fine irregularities are formed on the surface of the low refractive index layer, and black tightening may be deteriorated.
The average particle diameter of the inorganic fine particles is preferably 30% or more and 100% or less, more preferably 35% or more and 80% or less, and still more preferably 40% or more and 60% or less of the thickness of the low refractive index layer.
The inorganic fine particles may be either crystalline or amorphous, and may be monodispersed particles or aggregated particles as long as a predetermined particle size is satisfied. The shape is most preferably a spherical diameter, but there is no problem even if the shape is indefinite.
The average particle diameter of the inorganic fine particles is measured by a Coulter counter.

  In order to further reduce the increase in the refractive index of the low refractive index layer, the inorganic fine particles preferably have a hollow structure, and the refractive index of the inorganic fine particles is preferably 1.17 to 1.40, more preferably 1.17 to 1.35, more preferably 1.17 to 1.30. The refractive index here represents not only the shell but also the refractive index of the entire particle having a hollow. At this time, when the radius of the cavity in the particle is a and the radius of the particle outer shell is b in the formula (II), the porosity x expressed by the following formula (II) is

(Formula II)
^{x = (4πa 3/3)} / (4πb 3/3) × 100

Preferably it is 10 to 60%, More preferably, it is 20 to 60%, Most preferably, it is 30 to 60%.
The refractive index of the inorganic fine particles was measured with an Abbe refractometer (manufactured by Atago Co., Ltd.).

Further, at least one kind of inorganic fine particles (hereinafter referred to as “small-size inorganic fine particles”) having an average particle size of less than 25% of the thickness of the low refractive index layer is referred to as “inorganic fine particles (hereinafter“ It may be used in combination with “large-size inorganic fine particles”.
Since the small-sized inorganic fine particles can exist in the gaps between the large-sized inorganic fine particles, they can contribute as a retaining agent for the large-sized inorganic fine particles.
When the low refractive index layer is 100 nm, the average particle size of the small-sized inorganic fine particles is preferably 1 nm to 20 nm, more preferably 5 nm to 15 nm, and particularly preferably 10 nm to 15 nm. Use of such inorganic fine particles is preferable in terms of raw material costs and a retaining agent effect.
As described above, the inorganic fine particles have an average particle diameter of 30 to 100% of the thickness of the low refractive index layer as described above, have a hollow structure, and have a refractive index of 1.17 to 1. What is 40 is used especially preferably.

Inorganic fine particles are treated with physical surface treatment such as plasma discharge treatment or corona discharge treatment in order to stabilize dispersion in the dispersion or coating solution, or to improve the affinity and binding properties with the binder component. Chemical surface treatment with a surfactant, a coupling agent, or the like may be performed. Of these, the use of a coupling agent is particularly preferred. As the coupling agent, an alkoxy metal compound (eg, titanium coupling agent, silane coupling agent) is preferably used. Of these, silane coupling treatment is particularly effective.
The coupling agent is used as a surface treatment agent for the inorganic fine particles of the low refractive index layer in advance for surface treatment prior to the preparation of the layer coating solution, and is further added as an additive during preparation of the layer coating solution. It is preferable to make it contain in a layer.
The inorganic fine particles are preferably dispersed in the medium in advance before the surface treatment in order to reduce the load of the surface treatment.

The low refractive index layer according to the present invention may contain amorphous organic fine particles. The organic fine particles are preferably polymer fine particles synthesized by polymerization reaction of monomers (for example, emulsion polymerization method). The organic fine particle polymer preferably contains a fluorine atom. The proportion of fluorine atoms in the polymer is preferably 35 to 80% by weight, and more preferably 45 to 75% by weight. It is also preferable to form microvoids in the organic fine particles by, for example, cross-linking the polymer forming the particles and reducing the volume.
The monomer used for the synthesis of the organic fine particles includes a fluorine atom used for synthesizing the fluorine-containing polymer. Examples of monomers include fluorination of fluoroolefins (eg, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole), acrylic acid or methacrylic acid Examples include alkyl esters and fluorinated vinyl ethers. A copolymer of a monomer containing a fluorine atom and a monomer not containing a fluorine atom may be used.
Examples of monomers that do not contain fluorine atoms include olefins, acrylic esters, methacrylic esters, styrenes, vinyl ethers, vinyl esters, acrylamides, methacrylamides, and acrylonitriles. Examples of polyfunctional monomers include dienes, esters of polyhydric alcohol and acrylic acid, esters of polyhydric alcohol and methacrylic acid, divinyl compounds, divinyl sulfone, bisacrylamides, and bismethacrylamides.

[Other substances contained in curable composition for low refractive index layer]
The curable composition is preferably the above-mentioned (A) fluorine-containing polymer, (B) inorganic fine particles and the (C) organosilane compound described below, if necessary, various additives and the above-mentioned radical polymerization initiator, It is prepared by adding a cationic polymerization initiator and further dissolving them in a suitable solvent. At this time, the concentration of the solid content is appropriately selected according to the use, but is generally about 0.01 to 60% by mass, preferably 0.5 to 50% by mass, particularly preferably 1% to 20% by mass. %.

  Curing agents such as polyfunctional (meth) acrylate compounds, polyfunctional epoxy compounds, polyisocyanate compounds, aminoplasts, polybasic acids or anhydrides thereof from the viewpoint of interfacial adhesion with the lower layer directly in contact with the low refractive index layer Can also be added in small amounts. When adding these, it is preferable to set it as the range of 30 mass% or less with respect to the total solid of a low refractive index layer film | membrane, It is more preferable to set it as the range of 20 mass% or less, The range of 10 mass% or less It is particularly preferable that

  In addition, for the purpose of imparting properties such as antifouling properties, water resistance, chemical resistance, and slipping properties, a known silicone compound or fluorine compound antifouling agent, slipping agent, and the like may be appropriately added. When these additives are added, it is preferably added in the range of 0.01 to 20% by mass of the total solid content of the low refractive index layer, more preferably in the range of 0.05 to 10% by mass. Particularly preferred is 0.1 to 5% by mass.

  Preferable examples of the silicone compound include those having a substituent at the terminal and / or side chain of a compound chain containing a plurality of dimethylsilyloxy units as repeating units. The compound chain containing dimethylsilyloxy as a repeating unit may contain a structural unit other than dimethylsilyloxy. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, fluoroalkyl group, polyoxyalkylene group, carboxyl group, amino group and the like. It is done. Although there is no restriction | limiting in particular in molecular weight, It is preferable that it is 100,000 or less, It is especially preferable that it is 50,000 or less, It is most preferable that it is 3000-30000. Although there is no restriction | limiting in particular in silicone atom content of a silicone type compound, it is preferable that it is 18.0 mass% or more, it is especially preferable that it is 25.0-37.8 mass%, and 30.0-37.0. Most preferably, it is mass%. Examples of preferred silicone compounds are X-22-174DX, X-22-2426, X-22-164B, X22-164C, X-22-170DX, X-22-176D, X, manufactured by Shin-Etsu Chemical Co., Ltd. -22-1821 (named above), manufactured by Chisso Corporation, FM-0725, FM-7725, FM-4421, FM-5521, FM6621, FM-1121, Gelest DMS-U22, RMS-033, RMS- 083, UMS-182, DMS-H21, DMS-H31, HMS-301, FMS121, FMS123, FMS131, FMS141, FMS221 (named above) but not limited thereto.

As the fluorine compound, a compound having a fluoroalkyl group is preferable. The fluoroalkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and a straight chain (for example, —CF ₂ CF ₃ , —CH ₂ (CF ₂ ) ₄ H, —CH ₂ (CF ₂ ) ₈ CF ₃ , —CH ₂ CH ₂ (CF ₂ ) ₄ H, etc.), even branched structures (eg, —CH (CF ₃ ) ₂ , —CH ₂ CF (CF ₃ ) ₂ , —CH (CH ₃ ) CF ₂ CF ₃ , —CH (CH ₃ ) (CF ₂ ) ₅ CF ₂ H, etc.), but alicyclic structures (preferably 5-membered or 6-membered rings such as perfluorocyclohexyl groups) , A perfluorocyclopentyl group or an alkyl group substituted with these, and may have an ether bond (for example, —CH ₂ OCH ₂ CF ₂ CF ₃ , —CH ₂ CH ₂ OCH ₂ C). ₄ F ₈ H, —CH ₂ CH ₂ OCH ₂ CH ₂ C ₈ F ₁₇ , —CH ₂ C H ₂ OCF ₂ CF ₂ OCF ₂ CF ₂ H, etc.). A plurality of the fluoroalkyl groups may be contained in the same molecule.
It is preferable that the fluorine-based compound further has a substituent that contributes to bond formation or compatibility with the low refractive index layer film. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, polyoxyalkylene group, carboxyl group, amino group and the like. The fluorine-based compound may be a polymer or an oligomer with a compound not containing a fluorine atom, and the molecular weight is not particularly limited. Although there is no restriction | limiting in particular in fluorine atom content of a fluorine-type compound, It is preferable that it is 20 mass% or more, It is especially preferable that it is 30-70 mass%, It is most preferable that it is 40-70 mass%. Examples of preferred fluorine-based compounds include Daikin Chemical Industries, Ltd., R-2020, M-2020, R-3833, M-3833 (named above), Dainippon Ink Co., Ltd., Megafac F-171. , F-172, F-179A, defender MCF-300 (trade name), etc., but are not limited thereto.

  For the purpose of imparting properties such as dust resistance and antistatic properties, a known cationic surfactant or a dustproof agent such as a polyoxyalkylene compound, an antistatic agent, or the like can be appropriately added. These dustproofing agent and antistatic agent may contain the structural unit as a part of the function in the above-mentioned silicone compound or fluorine compound. When these are added as additives, it is preferably added in the range of 0.01 to 20% by mass of the total solid content of the low refractive index layer, more preferably in the range of 0.05 to 10% by mass. Particularly preferred is 0.1 to 5% by mass. Examples of preferred compounds include, but are not limited to, Dainippon Ink Co., Ltd., Megafac F-150 (trade name), Toray Dow Corning Co., Ltd., SH-3748 (trade name), and the like. Do not mean.

[Solvent for low refractive index layer]
As the solvent used in the coating composition for forming the low refractive index layer used in the present invention, it is possible to dissolve or disperse each component, to easily form a uniform surface in the coating process and the drying process, Various solvents selected from the viewpoints of ensuring storage stability and having an appropriate saturated vapor pressure can be used. From the viewpoint of the drying load, it is preferable that a solvent having a boiling point of 100 ° C. or lower at normal pressure and room temperature as a main component and a small amount of a solvent having a boiling point of 100 ° C. or higher for adjusting the drying speed.
Examples of the solvent having a boiling point of 100 ° C. or lower include hydrocarbons such as hexane (boiling point 68.7 ° C.), heptane (98.4 ° C.), cyclohexane (80.7 ° C.), benzene (80.1 ° C.), Halogenated carbonization such as dichloromethane (39.8 ° C), chloroform (61.2 ° C), carbon tetrachloride (76.8 ° C), 1,2-dichloroethane (83.5 ° C), trichloroethylene (87.2 ° C) Hydrogens, diethyl ether (34.6 ° C), diisopropyl ether (68.5 ° C), dipropyl ether (90.5 ° C), ethers such as tetrahydrofuran (66 ° C), ethyl formate (54.2 ° C), Esters such as methyl acetate (57.8 ° C.), ethyl acetate (77.1 ° C.), isopropyl acetate (89 ° C.), acetone (56.1 ° C.), 2-butanone (methyl ethyl) Ketones such as Luketone, 79.6 ° C, methanol (64.5 ° C), ethanol (78.3 ° C), 2-propanol (82.4 ° C), 1-propanol (97.2 ° C), etc. Alcohols, cyano compounds such as acetonitrile (81.6 ° C.), propionitrile (97.4 ° C.), carbon disulfide (46.2 ° C.), and the like. Of these, ketones and esters are preferable, and ketones are particularly preferable. Among the ketones, 2-butanone is particularly preferable.
Examples of the solvent having a boiling point of 100 ° C. or more include, for example, octane (125.7 ° C.), toluene (110.6 ° C.), xylene (138 ° C.), tetrachloroethylene (121.2 ° C.), and chlorobenzene (131.7 ° C.). , Dioxane (101.3 ° C.), dibutyl ether (142.4 ° C.), isobutyl acetate (118 ° C.), cyclohexanone (155.7 ° C.), 2-methyl-4-pentanone (same as MIBK, 115.9 ° C.) 1-butanol (117.7 ° C.), N, N-dimethylformamide (153 ° C.), N, N-dimethylacetamide (166 ° C.), dimethyl sulfoxide (189 ° C.) and the like. Cyclohexanone and 2-methyl-4-pentanone are preferable.

[Low refractive index layer using sol-gel method]
Various sol-gel materials can also be used as the material for the low refractive index layer. As such a sol-gel material, metal alcoholates (alcohols such as silane, titanium, aluminum, and zirconium), organoalkoxy metal compounds, and hydrolysates thereof can be used. In particular, alkoxysilane, organoalkoxysilane and its hydrolyzate are preferable. Examples of these include tetraalkoxysilane (tetramethoxysilane, tetraethoxysilane, etc.), alkyltrialkoxysilane (methyltrimethoxysilane, ethyltrimethoxysilane, etc.), aryltrialkoxysilane (phenyltrimethoxysilane, etc.), dialkyl. Examples thereof include dialkoxysilane and diaryl dialkoxysilane. In addition, organoalkoxysilanes having various functional groups (vinyl trialkoxysilane, methylvinyl dialkoxysilane, γ-glycidyloxypropyltrialkoxysilane, γ-glycidyloxypropylmethyl dialkoxysilane, β- (3,4-epoxy) Dicyclohexyl) ethyltrialkoxysilane, γ-methacryloyloxypropyltrialkoxysilane, γ-aminopropyltrialkoxysilane, γ-mercaptopropyltrialkoxysilane, γ-chloropropyltrialkoxysilane, etc.), perfluoroalkyl group-containing silane compounds ( For example, it is also preferable to use (heptadecafluoro-1,1,2,2-tetradecyl) triethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, etc.). In particular, the use of a fluorine-containing silane compound is preferable in terms of lowering the refractive index of the layer and imparting water and oil repellency.

<Antistatic layer>
The optical film of the present invention preferably uses an antistatic layer in order to prevent dust (dust etc.) from adhering to the surface. The dust resistance is expressed by lowering the surface resistance value of the surface. The surface resistance value is preferably 1 × 10 ¹³ Ω / □ or less, more preferably 1 × 10 ¹² Ω / □ or less, and further preferably 1 × 10 ¹⁰ Ω / □ or less.
The antistatic layer is preferably provided between the light diffusion layer and the low refractive index layer, or between the transparent support and the light diffusion layer.

  When the antistatic layer is formed by coating, an antistatic layer may be formed by incorporating a conductive material (electroconductive particles, electron conductive organic compounds, etc.) in a binder (binder, etc.). preferable. In particular, an electron conductive type conductive material is preferable in that it is less susceptible to environmental changes and has stable conductive performance, so that it exhibits good conductive performance even in a low humidity environment.

  Preferred conductive materials used for the antistatic layer include tin oxide, antimony-doped tin oxide (ATO), indium oxide, tin-doped indium oxide (ITO), zinc oxide, aluminum-doped zinc oxide, and the like. Can be mentioned.

(About other coating layers)
In the optical film of the present invention, it is also preferable to provide a hard coat layer between the transparent support and the outermost layer in order to impart physical strength.
The hard coat layer is preferably formed by a crosslinking or polymerization reaction of an ionizing radiation curable compound. For example, a coating containing ionizing radiation-curable polyfunctional monomers or polyfunctional oligomers such as (meth) acryloyl group, vinyl group, styryl group, allyl group, etc. is applied on a transparent support and formed by crosslinking or polymerization reaction. can do.

  Specific examples of the photopolymerizable polyfunctional monomer having a photopolymerizable functional group include those exemplified for the light diffusion layer, and it is preferable to perform polymerization using a photopolymerization initiator and a photosensitizer. The photopolymerization reaction is preferably performed by ultraviolet irradiation after the hard coat layer is applied and dried.

The film thickness of the hard coat layer is preferably 1 to 10 μm, more preferably 2 to 7 μm, and particularly preferably 3 to 5 μm.
The strength of the hard coat layer is preferably H or more, more preferably 2H or more, and most preferably 3H or more in a pencil hardness test according to JIS K5400. Moreover, in the Taber test according to JIS K5400, the smaller the amount of wear of the test piece before and after the test, the better.

Resin, dispersant, surfactant, antistatic agent, silane coupling agent, thickener, anti-coloring agent, coloring agent (pigment, dye), antifoaming agent, leveling agent, flame retardant, UV Absorbers, adhesion promoters, polymerization inhibitors, antioxidants, surface modifiers, and the like can also be added. In addition, for the purpose of increasing the hardness of the hard coat layer, suppressing curing shrinkage, and controlling the refractive index, inorganic fine particles having an average primary particle diameter of 1 to 200 nm described later can be added.
Furthermore, for the purpose of imparting an antiglare function and a viewing angle expansion function of a liquid crystal display device, the hard coat layer can be made into an antiglare or scattering hard coat layer by containing particles having an average particle size of 0.2 to 10 μm. .

<Transparent support>
The transparent support is preferably a plastic film. As the plastic film, cellulose ester (eg, triacetyl cellulose, diacetyl cellulose, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose, nitrocellulose), polyamide, polycarbonate, polyester (eg, polyethylene terephthalate, polyethylene naphthalate, poly-1, 4-cyclohexanedimethylene terephthalate, polyethylene-1,2-diphenoxyethane-4,4′-dicarboxylate, polybutylene terephthalate), polystyrene (eg, syndiotactic polystyrene), polyolefin (eg, polypropylene, polyethylene, poly Methylpentene), polysulfone, polyethersulfone, polyarylate, polyetherimide, polymethylmethacrylate And polyether ketones. Triacetyl cellulose, polycarbonate, polyethylene terephthalate and polyethylene naphthalate are preferred, and triacetyl cellulose is particularly preferred when used in a liquid crystal display device.

  When the transparent support is a triacetyl cellulose film, a triacetyl cellulose dope prepared by dissolving triacetyl cellulose in a solvent is prepared by a single layer casting method or a multi-layer co-casting method. A cellulose film is preferred.

In particular, from the viewpoint of environmental conservation, a triacetyl cellulose film prepared using a triacetyl cellulose dope prepared by dissolving triacetyl cellulose in a solvent substantially free of dichloromethane by a low temperature dissolution method or a high temperature dissolution method is preferable. .
The triacetylcellulose film preferably used in the present invention is exemplified in the Japan Society for Invention and Innovation (public technical number 2001-1745).

The film thickness of the transparent support is not particularly limited, but the film thickness is preferably 1 to 300 μm, preferably 30 to 150 μm, particularly preferably 40 to 120 μm, and most preferably 40 to 100 μm.
The light transmittance of the transparent support is preferably 80% or more, and more preferably 86% or more.
The haze of the transparent support is preferably low. It is preferably 2.0% or less, and more preferably 1.0% or less.
The refractive index of the transparent support is preferably 1.40 to 1.70.

An infrared absorber or an ultraviolet absorber may be added to the transparent support. The addition amount of the infrared absorber is preferably 0.01 to 20% by mass of the transparent support, and more preferably 0.05 to 10% by mass.
In addition, an inert inorganic compound particle may be added to the transparent support as a slipping agent. Examples of the inorganic _{compound, SiO 2, TiO 2, BaSO} 4, CaCO 3, talc and kaolin.

  A surface treatment may be performed on the transparent support. Examples of the surface treatment include chemical treatment, mechanical treatment, corona discharge treatment, flame treatment, ultraviolet irradiation treatment, high frequency treatment, glow discharge treatment, active plasma treatment, laser treatment, mixed acid treatment and ozone oxidation treatment. Glow discharge treatment, ultraviolet irradiation treatment, corona discharge treatment and flame treatment are preferred, and glow discharge treatment and corona discharge treatment are particularly preferred.

<< organosilane compound >>
The organosilane compound that can be particularly preferably used for each layer of the optical film according to the present invention will be described.
At least one compound selected from organosilane compounds and derivatives thereof in terms of improving the physical strength of the film (such as scratch resistance) and the adhesion between the film and the layer adjacent to the film, such as hydrolysates of organosilane compounds and / Or the inclusion of a partial condensate thereof (hereinafter, the obtained reaction solution is also referred to as “sol component”) in terms of scratch resistance, particularly in terms of achieving both antireflection ability and scratch resistance. ,preferable.
This sol component is added to the coating composition, and after coating the coating composition, it is condensed by a drying and heating process to form a cured product, thereby functioning as a binder for the low refractive index layer. Moreover, in this invention, when it has the said fluorine-containing polymer, the binder which has a three-dimensional structure is formed by irradiation of actinic light.
The organosilane compound is preferably represented by the following general formula [A].

Formula [A]
(R ¹⁰ ) _a -Si (Z) _4-a

In the general formula [A], R ¹⁰ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, hexyl, decyl, hexadecyl and the like. The alkyl group is preferably an alkyl group having 1 to 30 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 6 carbon atoms. Examples of the aryl group include phenyl and naphthyl, and a phenyl group is preferable.
Z represents a hydroxyl group or a hydrolyzable group, for example, an alkoxy group (preferably an alkoxy group having 1 to 5 carbon atoms, such as a methoxy group or an ethoxy group), a halogen atom (for example, Cl, Br, I or the like). ), And R ² COO (R ² is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, such as CH ₃ COO, C ₂ H ₅ COO, etc.), preferably An alkoxy group, particularly preferably a methoxy group or an ethoxy group.
a represents an integer of 1 to 3, preferably 1 or 2, and particularly preferably 1.

When R ¹⁰ or Z there are a plurality, it may be different even multiple R ¹⁰ or Z respectively the same.
The substituent contained in R ¹⁰ is not particularly limited, but a halogen atom (fluorine, chlorine, bromine, etc.), hydroxyl group, mercapto group, carboxyl group, epoxy group, alkyl group (methyl, ethyl, i-propyl, propyl, t-butyl etc.), aryl groups (phenyl, naphthyl etc.), aromatic heterocyclic groups (furyl, pyrazolyl, pyridyl etc.), alkoxy groups (methoxy, ethoxy, i-propoxy, hexyloxy etc.), aryloxy (phenoxy etc.) ), Alkylthio groups (methylthio, ethylthio, etc.), arylthio groups (phenylthio, etc.), alkenyl groups (vinyl, 1-propenyl, etc.), acyloxy groups (acetoxy, acryloyloxy, methacryloyloxy, etc.), alkoxycarbonyl groups (methoxycarbonyl, ethoxy) Carbonyl, etc.), aryloxy Carbonyl groups (phenoxycarbonyl, etc.), carbamoyl groups (carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N-methyl-N-octylcarbamoyl, etc.), acylamino groups (acetylamino, benzoylamino, acrylicamino, methacrylamino) Etc.), and these substituents may be further substituted.

When there are a plurality of R ^{10 s} , at least one is preferably a substituted alkyl group or a substituted aryl group.
Among the organosilane compounds represented by the general formula [A], an organosilane compound having a vinyl polymerizable substituent represented by the following general formula [B] is preferable.

In the general formula [B], R ₁ represents a hydrogen atom, a methyl group, a methoxy group, an alkoxycarbonyl group, a cyano group, a fluorine atom, or a chlorine atom. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group. A hydrogen atom, a methyl group, a methoxy group, a methoxycarbonyl group, a cyano group, a fluorine atom, and a chlorine atom are preferable, a hydrogen atom, a methyl group, a methoxycarbonyl group, a fluorine atom, and a chlorine atom are more preferable, and a hydrogen atom and a methyl group Is particularly preferred.
Y ₁ represents a single bond or * -COO-**, * -CONH-** or * -O-**, preferably a single bond, * -COO-** or * -CONH-**. And * -COO-** are more preferred, and * -COO-** is particularly preferred. * Represents a position bonded to ═C (R ₁ ) —, and ** represents a position bonded to L ₁ .

L ₁ represents a divalent linking chain. Specifically, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted alkylene group having a linking group (for example, ether, ester, amide, etc.) inside, and a linking group inside. A substituted or unsubstituted arylene group, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, and an alkylene group having a linking group therein are preferred. An unsubstituted alkylene group and an unsubstituted arylene group Further, an alkylene group having an ether or ester linking group inside is more preferred, an unsubstituted alkylene group, and an alkylene group having an ether or ester linking group inside is particularly preferred. Examples of the substituent include a halogen, a hydroxyl group, a mercapto group, a carboxyl group, an epoxy group, an alkyl group, and an aryl group, and these substituents may be further substituted.

d represents 0 or 1; When a plurality of Zs are present, the plurality of Zs may be the same or different. d is preferably 0.
R ¹⁰ has the same meaning as in formula [A], preferably a substituted or unsubstituted alkyl group or an unsubstituted aryl group, and more preferably an unsubstituted alkyl group or an unsubstituted aryl group.
Z is synonymous with the general formula [A], preferably a halogen atom, a hydroxyl group or an unsubstituted alkoxy group, more preferably a chlorine atom, a hydroxyl group or an unsubstituted alkoxy group having 1 to 6 carbon atoms, a hydroxyl group or a carbon number of 1 -3 alkoxy groups are more preferred, and methoxy groups are particularly preferred.

  Two or more compounds of the general formula [A] and general formula [B] may be used in combination. Although the specific example of a compound represented by general formula [A] and general formula [B] is shown below, it is not limited.

  Of these, (M-1), (M-2), and (M-5) are particularly preferable.

  The hydrolyzate and / or partial condensate of the organosilane compound is generally produced by treating the organosilane compound in the presence of a catalyst. Catalysts include inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid; organic acids such as oxalic acid, acetic acid, formic acid, methanesulfonic acid and toluenesulfonic acid; inorganic bases such as sodium hydroxide, potassium hydroxide and ammonia; triethylamine, Examples thereof include organic bases such as pyridine; metal alkoxides such as triisopropoxyaluminum and tetrabutoxyzirconium; metal chelate compounds having a metal such as Zr, Ti or Al as a central metal. In the present invention, it is preferable to use a metal chelate compound, an acid catalyst of inorganic acids and organic acids. Inorganic acids are preferably hydrochloric acid and sulfuric acid, and organic acids are preferably those having an acid dissociation constant (pKa value (25 ° C.)) of 4.5 or less in water, and further, acid dissociation constants in hydrochloric acid, sulfuric acid and water. Is preferably an organic acid having an acid dissociation constant of 2.5 or less in hydrochloric acid, sulfuric acid or water, specifically methanesulfonic acid, oxalic acid, phthalic acid, malon. Acid is more preferred, and oxalic acid is particularly preferred.

As the metal chelate compound, an alcohol represented by a general formula R ⁶ OH (wherein R ⁶ represents an alkyl group having 1 to 10 carbon atoms) and R ⁴ COCH ₂ COR ⁵ (where R ⁴ is the number of carbon atoms) 1 to 10 alkyl groups, R ⁵ is an alkyl group having 1 to 10 carbon atoms or a compound represented by an alkoxy group having 1 to 10 carbon atoms) and selected from Zr, Ti, and Al. Any metal having a central metal as the metal can be used without any particular limitation. Within this category, two or more metal chelate compounds may be used in combination. The metal chelate compound used in the present invention has the general formula Zr (OR ⁶ ) _p1 (R ⁴ COCHCOR ⁵ ) _p2 , Ti (OR ⁶ ) _q1 (R ⁴ COCHCOR ⁵ ) _q2 , and Al (OR ⁶ ) _r1 (R ⁴ Those selected from the group of compounds represented by COCHCOR ⁵ ) _r2 are preferred and serve to promote the condensation reaction of the hydrolyzate and / or partial condensate of the organosilane compound.
R ⁶ and R ⁴ in the metal chelate compound may be the same or different and each is an alkyl group having 1 to 10 carbon atoms, specifically, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, sec -Butyl group, t-butyl group, n-pentyl group, phenyl group and the like. R ⁵ represents an alkyl group having 1 to 10 carbon atoms as described above, or an alkoxy group having 1 to 10 carbon atoms such as a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, and n-butoxy. Group, sec-butoxy group, t-butoxy group and the like. Moreover, p1, p2, q1, q2, r1, and r2 in the metal chelate compound represent integers determined so as to be p1 + p2 = 4, q1 + q2 = 4, and r1 + r2 = 3, respectively.

  Specific examples of these metal chelate compounds include tri-n-butoxyethyl acetoacetate zirconium, diisopropoxybis (acetylacetonato) titanium, diisopropoxyethyl acetoacetate aluminum, tris (ethyl acetoacetate) aluminum and the like. It is done. These metal chelate compounds can be used individually by 1 type or in mixture of 2 or more types. Moreover, the partial hydrolyzate of these metal chelate compounds can also be used.

  In the present invention, it is preferable that a β-diketone compound and / or a β-ketoester compound is further added to the curable composition. This will be further described below.

The β-diketone compound and / or β-ketoester compound represented by the general formula R ⁴ COCH ₂ COR ⁵ is preferably used in the present invention, and the stability of the curable composition used in the present invention is improved. It acts as an agent. Here, R ⁴ represents an alkyl group having 1 to 10 carbon atoms, and R ⁵ represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms. R ⁴ and R ⁵ constituting the β- diketone compound and / or β- ketoester compound are the same as R ⁴ and R ⁵ constituting the metal chelate compound.

  Specific examples of the β-diketone compound and / or β-ketoester compound include acetylacetone, methyl acetoacetate, ethyl acetoacetate, acetoacetate-n-propyl, acetoacetate-i-propyl, acetoacetate-n-butyl, acetoacetate. Acetic acid-sec-butyl, acetoacetic acid-t-butyl, 2,4-hexane-dione, 2,4-heptane-dione, 3,5-heptane-dione, 2,4-octane-dione, 2,4-nonane -Dione, 5-methyl-hexane-dione and the like can be mentioned. Of these, ethyl acetoacetate and acetylacetone are preferred, and acetylacetone is particularly preferred.

The compounding amount of the organosilane compound is preferably 0.1 to 50% by mass, more preferably 0.5 to 20% by mass, and most preferably 1 to 10% by mass based on the total solid content of the content layer.
The organosilane compound may be directly added to the curable composition (coating liquid for antiglare layer, low refractive index layer, etc.), but the hydrolyzate and / or partial condensate of the organosilane compound and A composition containing a metal chelate compound is prepared, and a liquid obtained by adding a β-diketone compound and / or a β-ketoester compound thereto is contained in at least one coating liquid of an antiglare layer or a low refractive index layer. It is preferable to apply at least.

  5-100 mass% is preferable, as for the usage-amount of the sol component of the organosilane with respect to a binder in a content layer, 5-40 mass% is more preferable, 8-35 mass% is still more preferable, and 10-30 mass% is especially preferable. . If the amount used is small, it is difficult to obtain the effect of the present invention, and if it is too large, the refractive index increases or the shape / surface shape of the film deteriorates.

  Preferred layers for adding the organosilane compound are an antistatic layer, a hard coat layer, an antiglare layer, a light diffusion layer, a high refractive index layer, a low refractive index layer, and an outermost layer, more preferably a hard coat layer. , An antiglare layer, a light diffusion layer, a low refractive index layer, and an outermost layer, particularly preferably an outermost layer and an adjacent layer of the outermost layer.

<Optical film formation method>
In the present invention, each layer constituting the optical film is preferably prepared by a coating method. When formed by coating, each layer is formed by dip coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating, micro gravure coating or extrusion coating (US Pat. No. 2,681, 294 specification) or a die coating method (described in Japanese Patent Application Laid-Open Nos. 2003-20097, 2003-211052, 2003-236434, 2003-260400, 2003-260402, etc.). . Two or more layers may be applied simultaneously. For the simultaneous application method, US Pat. Nos. 2,761,791, 2,941,898, 3,508,947, 3,526,528 and Yuji Harasaki, “Coating Engineering ", page 253, Asakura Shoten (1973). Wire bar coating, gravure coating, micro gravure coating and die coating are preferred. In particular, a micro gravure coating method and a die coating method are preferable.

The micro gravure coating method is usually a gravure roll having a diameter of about 10 to 100 mm, preferably about 20 to 50 mm and having a gravure pattern engraved on the entire circumference, below the support and in the direction of conveyance of the support. In this coating method, the roll is rotated in the reverse direction, the excess coating liquid is scraped off from the surface of the gravure roll by a doctor blade, and a fixed amount of coating liquid is transferred to a support.
In the micro gravure coating method, the number of lines of the gravure pattern engraved on the gravure roll is preferably 50 to 800 lines / inch, more preferably 100 to 300 lines / inch. The depth of the gravure pattern is preferably 1 to 600 μm, more preferably 5 to 200 μm. The rotation speed of the gravure roll is preferably 3 to 800 rpm, more preferably 5 to 200 rpm. It is preferable that the conveyance speed of a support body is 0.5-100 m / min, More preferably, it is 1-50 m / min.

  In the die coating method, a coating film is formed on a web by coating the web continuously running supported by a backup roller from a slot die in which pockets are formed. By appropriately adjusting the distance between the tip of the slot die and the web on the upstream side and the downstream side of the slot member with respect to the web traveling direction, it is possible to accurately apply a wet film thickness of several tens of μm or less.

<< Physical performance of optical film >>
The optical film according to the present invention preferably has a dynamic friction coefficient of 0.25 or less on the surface having the coated outermost layer in order to improve physical strength (such as scratch resistance). The coefficient of dynamic friction is as follows. When a load of 0.98 N is applied to a stainless hard sphere having a diameter of 5 mm and the surface having the outermost layer is moved at a speed of 60 cm / min, the surface having the outermost layer and the stainless hard sphere having a diameter of 5 mm The coefficient of dynamic friction between Preferably it is 0.17 or less, Most preferably, it is 0.15 or less.
Further, in order to improve the antifouling performance, the optical film preferably has a contact angle with water of the surface having the outermost layer of 80 ° or more. More preferably, it is 90 ° or more, and particularly preferably 100 ° or more.
Furthermore, the haze of the film is preferably 0.5 to 60%, more preferably 1 to 50%, and most preferably 1 to 40%.
Furthermore, the reflectance of the film is preferably as low as possible, preferably 3.0% or less, more preferably 2.5% or less, still more preferably 2.0% or less, and particularly preferably 1.5% or less.

<< Protective film for polarizing plate >>
The optical film of the present invention can be used as a protective film for a polarizing film (protective film for polarizing plate). In this case, the contact angle with respect to water of the surface of the transparent support opposite to the side having the outermost layer, that is, the surface to be bonded to the polarizing film is preferably 40 ° or less. More preferably, it is 30 ° or less, and particularly preferably 25 ° or less. Setting the contact angle to 40 ° or less is effective in improving the adhesion with a polarizing film containing polyvinyl alcohol as a main component. This contact angle can be adjusted by the following saponification treatment conditions.

  As the transparent support of the antireflection film used as the protective film for polarizing plate, it is particularly preferable to use a triacetyl cellulose film.

Examples of the method for producing the protective film for polarizing plate in the present invention include the following two methods.
(1) Apply each of the above layers (eg, antistatic layer, hard coat layer, antiglare layer, low refractive index layer, high refractive index layer, outermost layer, etc.) on one surface of the saponified transparent support. Technique.
(2) After coating each of the above layers (eg, antistatic layer, hard coat layer, antiglare layer, low refractive index layer, outermost layer, etc.) on one surface of the transparent support, the side to be bonded to the polarizing film Saponification treatment method.

In the method (1), when only one surface of the transparent support is saponified, each layer is coated on the side not saponified. When both surfaces of the transparent support are saponified, the surface of the saponified transparent support on the side where each layer is applied is surface-treated by a technique such as corona discharge treatment, glow discharge treatment, flame treatment, etc. It is preferable to coat each layer.
In said (2), it is preferable to immerse the whole optical film in a saponification liquid. In this case, the surface of the optical film having the respective layers can be protected with a protective film and immersed in a saponification solution, and the surface of the transparent support to be bonded to the polarizing film can be saponified.
Furthermore, a saponification treatment solution can be applied to the surface of the transparent support to be bonded to the polarizing film of the optical film, and the saponification treatment can be performed on the side to be bonded to the polarizing film.
The saponification treatment is carried out after antireflection performance is imparted on the protective film, whereby the cost can be further reduced, and the method (2) is particularly preferable in that the protective film for polarizing plate can be produced at a low cost.

Protective films for polarizing plates have optical performance (low reflection performance, antiglare performance, etc.), physical performance (such as scratch resistance), chemical resistance, antifouling performance (contamination resistance, etc.), and weather resistance (moisture and heat resistance, light resistance). ) And dustproof performance, it is preferable to satisfy the performance described as the optical film of the present invention.
Accordingly, the surface resistance value of the surface having the outermost layer is preferably 1 × 10 ¹³ Ω / □ or less, more preferably 1 × 10 ¹² Ω / □ or less, and 1 × 10 ¹⁰ Ω / □. More preferably, it is as follows.
The coefficient of dynamic friction on the surface having the outermost layer is preferably 0.25 or less. Preferably it is 0.17 or less, Most preferably, it is 0.15 or less.
Further, the contact angle with respect to water on the surface having the outermost layer is preferably 90 ° or more. More preferably, it is 95 ° or more, and particularly preferably 100 ° or more.

(Saponification treatment)
The saponification treatment is preferably carried out by a known method, for example, by immersing the transparent support or the optical film in an alkali solution for an appropriate time.
The alkaline liquid is preferably a potassium hydroxide aqueous solution and / or a sodium hydroxide aqueous solution. A preferred concentration is 0.5 to 3 mol / l, particularly preferably 1 to 2 mol / l. The liquid temperature of a preferable alkali liquid is 30-70 degreeC, Most preferably, it is 40-60 degreeC.
After being immersed in the alkaline solution, it is preferable to sufficiently wash with water or neutralize the alkaline component by immersing in a dilute acid so that the alkaline component does not remain in the film.

By saponification treatment, the surface of the transparent support is hydrophilized. The protective film for polarizing plate is used by adhering the hydrophilic surface of the transparent support to the polarizing film.
The hydrophilized surface is effective for improving the adhesion with a polarizing film containing polyvinyl alcohol as a main component.
The saponification treatment is preferably carried out so that the contact angle with water on the surface of the transparent support opposite to the side having the antiglare layer or the low refractive index layer is 40 ° or less. More preferably, it is 30 ° or less, particularly preferably 25 ° or less.

"Polarizer"
The polarizing plate of this invention has the optical film of this invention in at least one of the protective film (protective film for polarizing plates) of a deflection | deviation film | membrane. As described above, the polarizing plate protective film has a water contact angle of 40 ° or less on the surface of the transparent support opposite to the side having the outermost layer, that is, the surface to be bonded to the polarizing film. preferable.

By using the optical film of the present invention as a protective film for a polarizing plate, a polarizing plate having an antireflection function can be produced, and the cost can be greatly reduced and the display device can be thinned.
Further, the polarizing plate using the optical film of the present invention as one of the two protective films and the optical compensation film having optical anisotropy described later as the other is further provided with a contrast in a bright room of a liquid crystal display device. This is preferable because the viewing angle in the vertical and horizontal directions can be greatly widened.

<Optical compensation film>
The optical compensation film (retardation film) can improve viewing angle characteristics of a liquid crystal display screen.
As the optical compensation film, a known film can be used, but in terms of widening the viewing angle, an optically anisotropic layer made of a compound having a discotic structural unit described in JP-A-2001-100042 is disclosed. An optical compensation film characterized in that the angle formed by the discotic compound and the film surface changes in the depth direction of the optically anisotropic layer is preferable. That is, the orientation state of the compound having a discotic structural unit is preferably, for example, a hybrid orientation, a bent orientation, a twist orientation, a homogeneous orientation, a homeotropic orientation, or the like, and particularly preferably a hybrid orientation. The angle is preferably increased as the distance from the support surface side of the optical compensation film increases in the optically anisotropic layer.
When the optical compensation film is used as a protective film for the polarizing film, the surface on the side to be bonded to the polarizing film is preferably saponified, and is preferably performed according to the saponifying process.

  Also, an embodiment in which the optically anisotropic layer further contains a cellulose ester, an embodiment in which an alignment layer is formed between the optically anisotropic layer and the transparent support of the optical compensation film, and the optically anisotropic layer An embodiment in which the transparent support of the optical compensation film has an optically negative uniaxial property and an optical axis in the normal direction of the surface of the transparent support, and an embodiment satisfying the following formula (III) is also preferable. .

Formula (III)
20 ≦ {(nx + ny) / 2−nz} × d ≦ 400

In formula (III), nx is the in-plane slow axis direction refractive index (in-plane maximum refractive index), ny
Is the refractive index in the direction perpendicular to the in-plane slow axis, and nz is the refractive index in the direction perpendicular to the surface. D is the thickness (nm) of the optically anisotropic layer.

<Image display device>
The optical film can be applied to an image display device such as a liquid crystal display device (LCD), a plasma display panel (PDP), an electroluminescence display (ELD), or a cathode ray tube display device (CRT). The optical film preferably has the transparent support side of the optical film adhered to the image display surface of the image display device.
The optical film and polarizing plate used in the present invention are twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), in-plane switching (IPS), optically compensated bend cell (OCB), etc. This mode can be preferably used for a transmissive, reflective, or transflective liquid crystal display device. Especially for a TN mode or IPS mode liquid crystal display device, as described in JP-A-2001-100043, etc., a polarizing plate having the optical compensation film and the optical film as a protective film is used. The viewing angle characteristic and the antireflection characteristic can be greatly improved.
Further, by using in combination with a commercially available brightness enhancement film (a polarized light separation film having a polarization selection layer, such as D-BEF manufactured by Sumitomo 3M Co., Ltd.), in a transmissive or transflective liquid crystal display device, Furthermore, a display device with high visibility can be obtained.
Further, by combining with a λ / 4 plate, it can be used to reduce reflected light from the surface and the inside as a polarizing plate for reflective liquid crystal or a surface protective plate for organic EL display.

In order to describe the present invention in detail, examples will be described below, but the present invention is not limited thereto.
(Synthesis of perfluoroolefin copolymer PF-1)

A stainless steel autoclave equipped with a stirrer was charged with 40 parts by mass of ethyl acetate, 14.7 parts by mass of hydroxyethyl vinyl ether, and 0.55 parts by mass of dilauroyl peroxide, and the system was deaerated and replaced with nitrogen gas. Further, 25 parts by mass of hexafluoropropylene (HFP) was introduced into the autoclave and the temperature was raised to 65 ° C. The pressure when the temperature in the autoclave reached 65 ° C. was 5.4 kg / cm ² (529 kPa). The reaction was continued for 8 hours while maintaining the temperature, and when the pressure reached 3.2 kg / cm ² (314 kPa), the heating was stopped and the mixture was allowed to cool. When the internal temperature dropped to room temperature, unreacted monomers were driven out, the autoclave was opened, and the reaction solution was taken out.
The obtained reaction solution was poured into a large excess of hexane, and the polymer was precipitated by removing the solvent by decantation. Further, this polymer was dissolved in a small amount of ethyl acetate and reprecipitated twice from hexane to completely remove the residual monomer. After drying, 28 parts by mass of the polymer product was obtained.
Next, 20 parts by mass of the polymer product was dissolved in 100 parts by mass of N, N-dimethylacetamide, and 11.4 parts by mass of acrylic acid chloride was added dropwise under ice cooling, followed by stirring at room temperature for 10 hours. Ethyl acetate was added to the reaction solution and washed with water. The organic layer was extracted and concentrated, and the obtained polymer was reprecipitated with hexane to obtain 19 parts by mass of the perfluoroolefin copolymer PF-1. The obtained perfluoroolefin copolymer had a refractive index of 1.421.
The perfluoroolefin copolymer PF-1 was dissolved in methyl ethyl ketone to obtain a solution having a solid content concentration of 30%.

(Preparation of organosilane compound A solution)
A reactor equipped with a stirrer and a reflux condenser, 120 parts by mass of methyl ethyl ketone, 100 parts by mass of 3-acryloxypropyltrimethoxysilane (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.), 3 parts by mass of diisopropoxyaluminum ethyl acetoacetate After adding a part and mixing, 30 mass parts of ion-exchange water was added, and it was made to react at 60 degreeC for 4 hours. The solution was cooled to room temperature to obtain a solution of organosilane compound A. The mass average molecular weight was 1600, and among the components higher than the oligomer component, the component having a molecular weight of 1000 to 20000 was 100%. Further, when analyzed by gas chromatography, the raw material 3-acryloxypropyltrimethoxysilane hardly remained.

(Preparation of curable multi-branched polymer [RHB-1]) 0.1 mol of 1,3,5-cyclohexanetricarboxylic acid was heated to 120 ° C. while stirring and replacing with nitrogen. To this, 0.9 mol of 5- (2-hydroxyethoxy) benzene-1,3-dicarboxylic acid and 1.2 mmol of methanesulfonic acid were added and reacted at 140 ° C. for 2 hours while removing generated water. Then, it was made to react for 30 minutes, depressurizing at a pressure reduction degree of 2.5 kPa, and multibranched polymer [HB-1] was prepared.
Next, 1.2 mol of 2-hydroxyethyl methacrylate and 1.0 part by mass of t-butylhydroquinone were added to the obtained multi-branched polymer [HB-1] and reacted at 60 ° C. for 3 hours. The reaction product was cooled, dissolved in chloroform, washed with alkaline water, washed with 1% hydrochloric acid, washed with water and dried to obtain a curable multi-branched polymer [RHB-1].

Preparation of (Curable Multibranched Polymer [RHB-2]) Polyester type dendrimer “BOLTORN (RTG) 2G” (having 16 surface hydroxyl groups; manufactured by Perstorp) 10 parts by mass and tetrahydrofuran 23 parts by mass While stirring at room temperature, 3.5 parts by mass of sodium hydride was added. Next, a mixed liquid of 19 parts by mass of epibromohydrin and 45 parts by mass of tetrahydrofuran was added dropwise over 1 hour, heated to 50 ° C. and stirred for 6 hours. After stirring, the mixture was cooled to room temperature, the reaction product was poured into 1 liter of water, extracted with 600 ml of toluene, washed, and dried. Toluene in the extract was removed under reduced pressure to obtain a curable multi-branched polymer [RHB-2].

(Preparation of light diffusion layer coating composition A-1)
To 47.0 parts by mass of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (KAYARAD PET-30, manufactured by Nippon Kayaku Co., Ltd.), 22.5 parts by mass of toluene was added and stirred. To this, 2.0 parts by mass of a polymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.), 0.05 parts by mass of a fluorine-based surface improver (FP-149), an organosilane compound (KBM-5103, 10.0 parts by mass of Shin-Etsu Chemical Co., Ltd.) and 16.0 parts by mass of a 30% toluene solution of polymethyl methacrylate (molecular weight 120,000) were added and stirred and dissolved. After applying this solution, the refractive index of the coating film obtained by ultraviolet curing was 1.51.
Furthermore, 20.0 parts by mass of a 30% toluene dispersion of crosslinked poly (acryl-styrene) particles having an average particle diameter of 3.5 μm (refractive index of 1.536) dispersed in this solution for 20 minutes at 10,000 rpm with a polytron disperser, and After adding 13.3 parts by mass of a 30% toluene dispersion of crosslinked poly (acryl-styrene) particles (refractive index 1.536) having an average particle diameter of 2.5 μm dispersed under the same conditions, propylene glycol 3.8 was further added. The mass part was added and it stirred for 10 minutes with the air disper.
The mixed solution was filtered through a polypropylene filter having a pore size of 30 μm to prepare a light diffusion layer coating composition A-1.

(Preparation of coating composition A-2 for light diffusion layer)
A mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku Co., Ltd.) 25.6 parts by mass was diluted with 46.3 parts by mass of methyl isobutyl ketone. Furthermore, 1.3 parts by mass of a polymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) was added and mixed and stirred. Subsequently, 0.04 parts by mass of a fluorine-based surface improver (FP-149), 5.2 parts by mass of a silane coupling agent (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.), and a cellulose having a molecular weight of 40,000. 0.50 part by mass of acetate butyrate (CAB-531-1, Eastman Chemical Co., Ltd.) was added and stirred for 120 minutes with an air disper to completely dissolve the solute. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.52.
Further, 12.6 of a 30% methyl isobutyl ketone dispersion of crosslinked poly (acryl-styrene) particles having an average particle size of 3.5 μm (refractive index of 1.536) dispersed in this solution for 20 minutes at 10,000 rpm with a Polytron disperser. After adding 8.4 parts by mass of a 30% methyl isobutyl ketone dispersion of crosslinked poly (acryl-styrene) particles (refractive index of 1.536) having an average particle diameter of 2.5 μm dispersed under the same conditions as those by mass, 4.8 parts by mass of glycol was added and stirred with an air disperser for 10 minutes.
The mixed solution was filtered through a polypropylene filter having a pore diameter of 30 μm to prepare a light diffusion layer coating composition A-2.

(Preparation of coating composition A-3 to A-20 for light diffusion layer)
Except that the composition of light-transmitting resin particles, the average particle diameter, the hydrophilic high boiling point solvent species, and the monomer species are changed as shown in Table 1 with respect to the coating composition A-2 for the light diffusion layer. Light diffusion layer coating compositions A-3 to A-20 were prepared in exactly the same manner as coating liquid A-2.

(Preparation of coating compositions for light diffusion layer for comparison)
The coating composition except that the composition of the translucent resin particles, the combination of the particles, and the amount of the hydrophilic high-boiling solvent were changed as shown in Table 1 with respect to the coating composition A-2 for the light diffusion layer. Comparative light diffusion layer coating compositions 1 to 2 were prepared in exactly the same manner as A-2.
In addition, when the amount of translucent resin particles is reduced, in order to make the total content of the translucent resin particles the same as A-2, the other translucent particle amount equivalent to the reduced amount is used. Increased the amount. Further, when the amount of the hydrophilic high-boiling solvent was reduced, the remaining amount of the low-boiling solvent equivalent to the reduced amount was increased in order to make the total content of the solvent the same as A-2.

(Preparation of coating composition for light diffusion layer for comparison)
The light diffusion layer for comparison was the same as the coating liquid A-1, except that the hydrophilic high boiling point solvent amount was changed as shown in Table 1 with respect to the coating composition A-1 for the light diffusion layer. A coating composition for use was prepared.

(Preparation to a light diffusing layer coating composition for comparison)
Except for changing the composition of the solvent to methyl ethyl ketone without changing the total amount of the organic solvent to the coating composition A-2 for the light diffusing layer, the coating solution A-2 is exactly the same. Thus, a comparative light diffusion layer coating composition was prepared.

1) Particle composition: P1 = crosslinked poly (styrene / methyl methacrylate) = 50/50 (I / O value = 0.49)
P2 = Cross-linked polystyrene (I / O value = 0.09)
2) Hydrophilic organic solvent: PG = propylene glycol (I / O value = 3.3)
EG = ethylene glycol (I / O value = 5.0)
DMF = N, N-dimethylformamide (I / O value = 2.3)
3) Hydrophobic organic solvent: Toluene (I / O = 0.11)
MIBK = methyl isobutyl ketone (I / O value = 0.59)
MEK = methyl ethyl ketone (I / O value = 0.81)
MIBK / MEK = Methyl isobutyl ketone / Methyl ethyl ketone (7/3) (I / O value = 0.59 / 0.81)
4) Monomer type: PETA = KAYARAD PET-30 (Nippon Kayaku) (I / O value = 1.16)
DPHA = KAYARAD DPHA (Nippon Kayaku) (I / O value = 1.04)
EO-TMP (1) = Ethylene oxide-added trimethylolpropane triacrylate (EO average 3.5 groups / 1 molecule) (I / O value = 1.22)
EO-TMP (2) = Ethylene oxide-added trimethylolpropane triacrylate (EO average 6 groups / 1 molecule) (I / O value = 1.73)

(Preparation of coating composition L-1 for low refractive index layer)
13.0 parts by mass of heat-crosslinkable fluorine-containing polymer having a refractive index of 1.42 (JN7228A, solid content concentration 6%, manufactured by JSR Corporation), MEK dispersion of silica fine particles (MEK-ST-L, average particle diameter) 45 nm, solid content concentration 30%, manufactured by Nissan Chemical Industries, Ltd.) 1.3 parts by mass, the above organosilane compound A solution 0.6 parts by mass, methyl ethyl ketone 5.0 parts by mass and cyclohexanone 0.6 parts by mass were added. And stirred. The mixture was filtered through a polypropylene filter having a pore diameter of 1 μm to prepare a coating composition L-1 for a low refractive index layer. The refractive index of the coating film formed from this paint was 1.42.

(Preparation of coating composition L-2 for low refractive index layer)
In 15.0 parts by mass of a heat-crosslinkable fluorine-containing polymer having a refractive index of 1.42 (JN7228A, solid content concentration 6%, manufactured by JSR Corporation), a MEK dispersion of silica fine particles (MEK-ST, average particle size 15 nm, Solid content concentration 30%, manufactured by Nissan Chemical Industries, Ltd.) 0.6 parts by mass, silica fine particle MEK dispersion (MEK-ST-L, average particle size 45 nm, solid content concentration 30%, Nissan Chemical Industries, Ltd.) (Product) 0.8 parts by mass, 0.4 parts by mass of the organosilane compound A solution, 3.0 parts by mass of methyl ethyl ketone, and 0.6 parts by mass of cyclohexanone were added and stirred. The mixture was filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating composition L-2 for a low refractive index layer. The refractive index of the coating film formed from this paint was 1.42.

(Preparation of MEK dispersion of hollow silica fine particles)
Hollow silica fine particle sol (Isopropyl alcohol silica sol, manufactured by Catalyst Chemical Industry Co., Ltd., average particle diameter 60 nm, shell thickness 10 nm, silica concentration 20 mass%, silica particle refractive index 1.31, Preparation Example 4 of JP-A-2002-79616 500 parts by weight, 30 parts acryloyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.), and diisopropoxyaluminum ethyl acetate (trade names: Kerope EP-12, Hope Pharmaceutical ( 9 parts of ion-exchanged water was added after adding and mixing 1.5 parts). After reacting at 60 ° C. for 8 hours, the mixture was cooled to room temperature, and 1.8 parts of acetylacetone was added. While adding methyl ethyl ketone so that the content of silica was almost constant in 500 g of this dispersion, solvent substitution by vacuum distillation was performed at a pressure of 20 kPa. There was no generation of foreign matter in the dispersion, and the viscosity when the solid content concentration was adjusted to 20% by mass with methyl ethyl ketone was 5 mPa · s at 25 ° C. When the residual amount of isopropyl alcohol in the obtained dispersion A-1 was analyzed by gas chromatography, it was 1.5%.

(Preparation of coating composition L-3 for low refractive index layer)
13.0 parts by mass of a heat-crosslinkable fluorine-containing polymer having a refractive index of 1.42 (JN7228A, solid content concentration 6%, manufactured by JSR Corporation) was added to the MEK dispersion of the above-described hollow silica fine particles (refractive index 1.31, 1.95 parts by mass (average particle size 60 nm, solid content concentration 20%), 0.6 parts by mass of the organosilane compound A solution, 4.35 parts by mass of methyl ethyl ketone, and 0.6 parts by mass of cyclohexanone were added and stirred. The mixture was filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating composition L-3 for a low refractive index layer. The refractive index of the coating film formed from this paint was 1.40.

(Preparation of coating composition L-4 for low refractive index layer)
To a mixed solvent of isopropyl alcohol / methyl ethyl ketone = 1/1 (mass ratio), 1 mol of tetramethoxysilane and 2 mol of 0.1N hydrochloric acid were added. A hydrolysis reaction was performed by stirring at room temperature for 2 hours to prepare a hydrolyzate solution of tetramethoxysilane.
Isopropyl alcohol / methyl ethyl ketone = 1/1 (mass ratio), tetramethoxysilane hydrolyzate 9.0 parts by mass, pentaerythritol triacrylate 1.0 part by mass, polymerization initiator (Irgacure 907, Ciba Specialty Chemicals ( Co., Ltd.) 0.5 parts by mass, and the solid content concentration was added to 4.5% by mass and stirred. The mixture was filtered through a polypropylene filter having a pore diameter of 1 μm to prepare a coating composition L-4 for a low refractive index layer. The refractive index of the coating film made of this paint was 1.45.

(Preparation of coating composition L-5 for low refractive index layer)
A polysiloxane compound having an acryloyl group (X-22-164C, manufactured by Shin-Etsu Chemical Co., Ltd.) is added to 15.0 parts by mass of the above-mentioned perfluoroolefin copolymer PF-1 (solid content concentration: 30%). 15 parts by mass, 0.23 parts by mass of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Specialty Chemicals Co., Ltd.), 81.8 parts by mass of methyl ethyl ketone and 2.8 parts by mass of cyclohexanone were added and stirred. The mixture was filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating composition L-6 for a low refractive index layer. The refractive index of the coating film formed from this paint was 1.43.

(Preparation of coating composition L-6 for low refractive index layer)
In 10.5 parts by mass of the above-mentioned perfluoroolefin copolymer PF-1 (solid content concentration 30%), MEK dispersion of silica fine particles (MEK-ST-L, average particle size 45 nm, solid content concentration 30%, Nissan Chemical Industries, Ltd.) 4.5 parts by mass, polysiloxane compound having an acryloyl group (X-22-164C, Shin-Etsu Chemical Co., Ltd.) 0.15 parts by mass, photopolymerization initiator (Irgacure 907, Ciba Specialty Chemicals Co., Ltd.) 0.23 parts by mass, 2.0 parts by mass of the organosilane compound A solution, 81.2 parts by mass of methyl ethyl ketone, and 2.8 parts by mass of cyclohexanone were added and stirred. The mixture was filtered through a polypropylene filter having a pore diameter of 1 μm to prepare a coating composition L-6 for a low refractive index layer. The refractive index of the coating film formed from this paint was 1.44.

(Preparation of coating composition L-7 for low refractive index layer)
In 10.5 parts by mass of the above-mentioned perfluoroolefin copolymer PF-1 (solid content concentration 30%), hollow silica fine particle MEK dispersion (refractive index 1.31, average particle size 60 nm, solid content concentration 20). %) 6.75 parts by mass, polysiloxane compound having an acryloyl group (X-22-164C, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.15 parts by mass, photopolymerization initiator (Irgacure 907, Ciba Specialty Chemicals ( 0.23 parts by mass, 0.2 parts by mass of the organosilane compound A solution, 81.2 parts by mass of methyl ethyl ketone, and 2.8 parts by mass of cyclohexanone were added and stirred. The mixture was filtered through a polypropylene filter having a pore diameter of 1 μm to prepare a coating composition L-7 for a low refractive index layer. The refractive index of the coating film made of this paint was 1.41.

(Preparation of coating composition L-8 for low refractive index layer)
A mixture (DPHA, Nippon Kayaku Co., Ltd.) of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate was added to 13.5 parts by mass of the above-mentioned perfluoroolefin copolymer PF-1 (solid content concentration 30%). 0.45 parts by mass, polysiloxane compound having an acryloyl group (X-22-164C, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.15 parts by mass, photopolymerization initiator (Irgacure 907, Ciba Specialty Chemicals Co., Ltd.) 0.23 parts by mass, 81.2 parts by mass of methyl ethyl ketone, and 2.8 parts by mass of cyclohexanone were added and stirred. The mixture was filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating composition L-8 for a low refractive index layer. The refractive index of the coating film formed from this paint was 1.44.

[Example 1]
On a triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Photo Film Co., Ltd.) having a film thickness of 80 μm and a width of 1340 mm, a light diffusion layer coating composition (A-1 to A-20, i to ho) is a slot die. It apply | coated on conditions with a conveyance speed of 25 m / min by the apply | coating system.
After drying at 100 ° C. for 25 seconds, using a 160 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) with nitrogen purge (oxygen concentration of 0.5% or less), irradiation is 400 mW / cm ² , irradiation The coating layer was cured by irradiating an ultraviolet ray with a quantity of 110 mJ / cm ² to produce a film with a light diffusion layer.

On the said light-diffusion layer, the coating composition (L-1 to L-8) for low refractive index layers was apply | coated by the slot die application | coating method on the conditions of the conveyance speed of 25 m / min.
Thereafter, the drying and curing conditions for L-1 to L-3 were as follows.
After drying at 120 ° C. for 150 seconds and further drying at 140 ° C. for 8 minutes, a 240 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) is used while purging with nitrogen (oxygen concentration 0.5% or less). Then, the coating layer was cured by irradiating ultraviolet rays having an illuminance of 400 mW / cm ² and an irradiation amount of 900 mJ / cm ² to form a low refractive index layer (outermost layer).
The drying and curing conditions for L-4 were as follows.
After drying at 120 ° C. for 150 seconds, the coating layer was cured by heat treatment at 140 ° C. for 20 minutes to form a low refractive index layer (outermost layer).
The drying and curing conditions for L-5 to L-8 were performed as follows.
After drying at 90 ° C. for 30 seconds, using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) with a nitrogen purge (oxygen concentration of 0.5% or less), an illuminance of 600 mW / cm ² and an irradiation amount The coating layer was cured by irradiating 600 mJ / cm ² of ultraviolet rays to form a low refractive index layer (outermost layer).

  The coating combination of the light diffusion layer and the low refractive index layer of the optical film sample according to the present invention was performed as described in Table 2.

(Evaluation of optical film)
About the obtained optical film sample, the following items were evaluated. The results are shown in Table 3.

(1) Evaluation of anti-glare property An exposed fluorescent lamp (8000 cd / cm ² ) without a louver was projected on the produced optical film, and the degree of blur of the reflected image was evaluated according to the following criteria.
It is preferable that the anti-glare property is blurred from the extent that the outline of the light source can be easily seen to the extent that the outline is not understood in the range where the entire screen does not become whitish.
A: The outline of the fluorescent lamp is hardly understood.
○: The outline of the fluorescent lamp is blurred and can be easily understood.
Δ: The outline of the fluorescent lamp is slightly blurred, but it can be seen (within the allowable range)
× ₍₁₎ : The outline of the fluorescent lamp can be clearly seen.
× ₍₂₎ : The outline of the fluorescent lamp is not known at all, and the whole looks quite whitish.
(2) Evaluation of average reflectance Using a spectrophotometer (manufactured by JASCO Corporation; V-550), in the wavelength region of 380 to 780 nm, using a integrating sphere, the spectral reflectance at an incident angle of 5 ° is calculated. It was measured. In the evaluation of the spectral reflectance, an average reflectance of 450 to 650 nm was used.

(3) Evaluation of blackness About the produced optical film, incident angle 60 degrees and reflection angles are 10 degrees-80 degrees using automatic variable angle photometer GP-5 (made by Murakami Color Research Laboratory Co., Ltd.). The reflected light was measured and determined as the reflectance with respect to the reference plate. The obtained reflectance value was converted into a density value, and a value of a reflection angle of 45 ° was adopted as a black value. A larger value indicates that the blackness is strong and there is a feeling of darkening.

  From the results of Table 3, the coated sample (sample Nos. 101 to 127) of the present invention containing two types of translucent resin particles of the light diffusion layer within the particle size definition of the present invention is one type of translucent particles. Even if two kinds are contained, the particle size range deviates from the present invention, or the blackness is increased as compared with the comparative coated sample (sample No. 128 to 133) using only one kind of organic solvent. I understand that. It is clear that this effect is due to the present invention.

[Example 2]
(Evaluation of image display device)
Sample No. 1 of Example 1 101 to 127 optical films can be used for image display devices (transmission type, reflection type or transflective type liquid crystal display devices in TN, STN, IPS, VA, or OCB modes, plasma display panels (PDP), electro A luminescence display (ELD) and a cathode ray tube display (CRT) were mounted on the display surface. The image display device using the optical film of the present invention was excellent in antireflection properties and blackening properties.
Furthermore, there is no recess with a cut surface area of 100 μm ² or more, and the pixel size is 100 p.
There was no glare failure in the image display device at pi (100 pixels / inch: 100 pixels per inch length).

[Example 3]
(Preparation of protective film for polarizing plate)
A saponification solution in which a 1.5 N sodium hydroxide aqueous solution was kept at 50 ° C. was prepared. Further, a 0.01N dilute sulfuric acid aqueous solution was prepared.
Sample No. 1 of Example 1 In the optical films of 101 to 127, the surface of the transparent support opposite to the side having the low refractive index layer (outermost layer) was saponified using the saponification solution.
The sodium hydroxide aqueous solution on the surface of the saponified transparent support is thoroughly washed with water, then washed with the above diluted sulfuric acid aqueous solution, and further, the diluted sulfuric acid aqueous solution is thoroughly washed with water and sufficiently dried at 100 ° C. I let you.
When the contact angle of the surface of the saponified transparent support on the side opposite to the side having the low refractive index layer (outermost layer) of the optical film was evaluated, it was 40 ° or less. Thus, the protective film for polarizing plates was produced.

(Preparation of polarizing plate)
An optical film (protective film for polarizing plate) of the present invention is prepared by using a 3% aqueous solution of PVA (manufactured by Kuraray Co., Ltd., PVA-117H) as an adhesive on one surface of the deflection film described in JP-A-2002-86554. ) Saponified triacetyl cellulose surface was attached. Further, a triacetyl cellulose film (Fuji Photo Film Co., Ltd., Fujitac, retardation value 3.0 nm) saponified in the same manner as above was bonded to the other surface of the polarizing film using the same adhesive. . Thus, the polarizing plate of this invention was produced.

(Evaluation of image display device)
The TN, STN, IPS, VA, OCB mode transmission type, reflection type, or transflective type liquid crystal display device equipped with the polarizing plate of the present invention thus manufactured has anti-reflection properties, particularly black. Excellent tightness.
Similar results were obtained with polarizing plates produced in the same manner as described above using various known deflection films.

[Example 4]
(Preparation of polarizing plate)
The surface of the optical compensation film (Wide View Film SA 12B, manufactured by Fuji Photo Film Co., Ltd.) opposite to the side having the optically anisotropic layer was saponified under the same conditions as in Example 3.
Sample No. 2 prepared in Example 3 was used. Instead of the saponified triacetyl cellulose film of the polarizing plate using the optical films 101 to 127, the optical compensation film prepared above (Wide View Film SA 12B, manufactured by Fuji Photo Film Co., Ltd.) Laminated with the same adhesive.
This polarizing plate is used as a polarizing plate on the viewing side of the transmission type TN liquid crystal cell (the viewing angle widening film is on the liquid crystal cell side), and as the polarizing plate on the backlight side, a viewing angle widening film and a triacetyl cellulose film are used as protective films. A liquid crystal display device using a polarizing plate (the viewing angle expansion film is on the liquid crystal cell side) was fabricated and evaluated visually. As a result, a clear image with little reflection of the background illumination was obtained, and the top, bottom, left and right fields of view were obtained. A liquid crystal display device having a very wide corner and high display quality was obtained.

  Similar results were obtained with polarizing plates produced in the same manner as described above using various known deflection films.

[Example 5]
(Evaluation of image display device)
Sample No. 1 of Example 1 When the 101 to 127 optical films were mounted on an organic EL display device, the antireflection property and the feeling of darkening were excellent.
Further, a polarizing plate protective film prepared in Example 3 on one side of the polarizing film and a polarizing plate having a λ / 4 plate on the other side were prepared in the same manner as in Example 3. When the above polarizing plate was mounted on an organic EL display device, reflection of light from the glass surface on which the polarizing plate was attached was also cut, and a display device with extremely high visibility was obtained.

[Example 6]
50 wt% of the mixture of dipentaerythritol pentaacrylate and dipentaacrylate hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) to be added to the coating composition A-2 for the light diffusion layer of the sample 102 in Example 1 above, Sample 201 was prepared in the same manner as Sample 102 except that the polyester acrylate dendrimer (A) described in Kaikai 2005-76005 and Synthesis Example 1 was used. As a result of the evaluation, an optical film having a resin composition with low curl and no cracks was obtained.
Sample 201 had an antiglare property of ◯, a reflectance of 2.7%, and a blackness of 4.3.

[Example 7]
40 wt% of a mixture of dipentaerythritol pentaacrylate and dipentaacrylate hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) to be added to the coating composition A-2 for the light diffusion layer of the sample 102 in Example 1 above, A sample 202 was produced in the same manner as the sample 102 except that the curable multi-branched polymer [RHB-1] prepared in the example was used. As a result of the evaluation, an optical film having a resin composition with low curl and no cracks was obtained.
This sample 202 had an antiglare property of ◯, a reflectance of 2.7%, and a blackness of 4.4.

[Example 8]
50 wt% of a mixture of dipentaerythritol pentaacrylate and dipentaacrylate hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) to be added to the coating composition A-2 for the light diffusion layer of the sample 102 in Example 1 It replaced with the curable multibranched polymer [RHB-1] prepared in the Example. Further, the amount of the polymerization initiator (Irgacure 184) was reduced to 0.65 parts by mass, and the same as Sample 102 except that 0.65 parts by mass of Rhodesyl Photoinitiator 2074 (manufactured by RHODIA) was added instead as a cationic polymerization initiator. Thus, a sample 203 was produced.
As a result of the evaluation, this sample was also an optical film having a resin composition with low curl and no cracks.
This sample 203 had an antiglare property of ◯, a reflectance of 2.6%, and a blackness of 4.3.

[Example 9]
A sample 301 was prepared in the same manner as the sample 102 except that the following coating composition L-11 was prepared and used instead of the coating composition L-1 for the low refractive index layer of the sample 102 in Example 1. .
(Coating composition L-11 for low refractive index layer)
80 parts by mass of the fluorine-containing thermosetting polymer described in Example 1 of JP-A-11-189621, 20 parts by mass of Cymel 303 (manufactured by Nippon Cytec Industries Co., Ltd.), and catalyst 4050 (manufactured by Nippon Cytec Industries Co., Ltd.) 2.0 parts by mass was dissolved in methyl ethyl ketone to give a solid content concentration of 6% by mass.
As a result of performing the same evaluation as in Example 1, a good optical film was obtained with antiglare property ◯, reflectance 2.7%, and blackness 4.4.

Claims (17)

  Light diffusion cured after applying a coating composition for a light diffusing layer comprising an ionizing radiation curable monomer, at least two kinds of translucent resin particles having different average particle diameters, and at least two kinds of organic solvents on a transparent support An optical film having a layer, wherein in the translucent resin particles, a particle type having a maximum average particle size and a second particle type having an average particle size of 30 to 90% with respect to the maximum particle type And an average particle diameter of the largest particle type is in the range of 20 to 90% with respect to the thickness after curing of the light diffusion layer.   2. The optical film according to claim 1, wherein the translucent resin particles contained in the light diffusion layer have an average particle diameter of 2 to 20 μm of the particle type having the largest average particle diameter.   3. The optical film according to claim 1, wherein among the translucent resin particles contained in the light diffusion layer, the average particle size of the particle type having the maximum average particle size is 3 to 7 μm. . The dispersity (V) of the total particles of the translucent resin particles contained in the light diffusion layer is represented by the following formula A, and the value is V = 0.6 to 1.0. The optical film according to claim 1.
Formula A
V = (90% volume cumulative particle size−10% volume cumulative particle size) / 50% volume cumulative particle size   The difference between the average value of the I / O value of the ionizing radiation curable monomer and the average value of the I / O value of the translucent resin particles is 0.3 to 3.0. The optical film in any one of 1-4.   The optical film according to claim 1, wherein the at least two organic solvents have at least one combination having a difference in I / O value of 0.25 or more.   The optical film according to claim 1, wherein a boiling point of at least one of the at least two organic solvents is 160 to 250 ° C.   8. The optical film according to claim 1, wherein the ionizing radiation curable monomer is at least two types, and at least one of them is a monomer having an I / O value of 1.2 or more. .   The optical film according to claim 8, wherein the ionizing radiation curable monomer having an I / O value of 1.2 or more is a monomer having an ethylene oxide group added thereto.   A curable multi-branched polymer (RHB) in which a light diffusing layer cured after applying the coating composition for a light diffusing layer has a photocurable and / or thermosetting reactive group at a branched end of the multibranched polymer (HB). The optical film according to claim 1, further comprising:   The optical film according to claim 10, wherein the multi-branched polymer (HB) is at least one selected from the group consisting of a dendrimer, a hyperbranched polymer, and a starburst polymer.   The photocurable and / or thermosetting reactive group of the curable multi-branched polymer (RHB) is at least one selected from a radical polymerizable group, a cationic polymerizable group, and a hydrolyzable silyl group. The optical film according to claim 10, wherein the optical film is a film.   A polyester polyol dendrimer compound (a) having 6 or more hydroxyl groups in one molecule and an ethylenically unsaturated group-containing monoester in terms of solid content in the light diffusion layer cured after coating the coating composition for light diffusion layer. The optical film according to claim 1, comprising an ethylenically unsaturated group-containing polyester dendrimer (A) which is a reaction product with the carboxylic acid (b).   An antireflection film comprising a low refractive index layer on a light diffusion layer of the optical film according to claim 1.   A polarizing plate, wherein the optical film according to claim 1 or the antireflection film according to claim 14 is used for at least one of two protective films of a polarizing film.   An optical display according to any one of claims 1 to 13, an antireflection film according to claim 14, or a polarizing plate according to claim 15 is disposed on an image display surface.   The image display device according to claim 16, wherein the image display device is a TN, STN, IPS, VA, or OCB mode transmissive, reflective, or transflective liquid crystal display device.