JP4900890B2 - Optical film, method for producing optical film, polarizing plate, and image display device using the same - Google Patents

Description

  The present invention relates to an optical film, in particular, an antireflection film, a polarizing plate, and an image display device.

Adds fine particles and binder to improve the scratch resistance, strength of cured products, and adhesion to other materials that come into contact with each other when used in applications such as adhesives, exterior paints, hard coats, and antireflection films. It is being considered.
When blending the fine particles and the binder, it is necessary that the fine particles do not cause unnecessary aggregation of the inorganic material. One of the commonly used methods is a method in which fine particles are dispersed in a solvent having affinity for the binder and then mixed with the binder to form a film. In order to obtain stable performance, it is important that the fine particles are stably dispersed in the solvent. Specifically, it is important to control hydrophilicity / hydrophobicity and steric hindrance on the surface of fine particles, and it is known that inorganic oxide fine particles are surface-treated with alkoxysilane. For example, Non-Patent Document 1 describes a method of dispersing inorganic particles in an organic solvent using a silane coupling agent.

  After the coating composition containing the fine particles and the binder has been stably prepared, the objective is to coat the composition on a support to achieve the desired performance. If the state of the fine particles in the coating film cannot be controlled, the performance such as the intended scratch resistance, the strength of the cured product, and the adhesion with other materials that have come into contact will vary. In particular, since the coating composition containing fine particles having a particle size of 1 micron or less has a large specific surface area, the interaction between the fine particles is large in the drying process of the organic solvent, and aggregation tends to occur. As a result, aggregation and phase separation may occur in the coating film, which may adversely affect the coating film performance.

  On the other hand, an antireflection film is generally used in a display device such as a cathode ray tube display (CRT), a plasma display (PDP), an electroluminescence display (ELD), or a liquid crystal display (LCD). In order to prevent reflection of light, it is arranged on the outermost surface of the display so as to reduce the reflectance by using the principle of optical interference.

  Such an antireflection film is prepared by forming a low refractive index layer having an appropriate thickness on the outermost surface, and optionally a high refractive index layer, a medium refractive index layer, a hard coat layer, etc. between the support and the support. it can. In order to realize a low reflectance, a material having a refractive index as low as possible is desired for the low refractive index layer. Further, since the antireflection film is used on the outermost surface, it is expected to function as a protective film for the display device. It is required that dirt and dust are difficult to adhere and that scratch resistance is strong. In order to realize high scratch resistance in a thin film having a thickness of around 100 nm, the strength of the coating itself and the adhesion to the lower layer are required.

  In order to lower the refractive index of the material, there are means of introducing fluorine atoms and lowering the density (introducing voids), but both are in the direction that the film strength and adhesion are impaired and the scratch resistance is lowered, and low Reconciling refractive index and high scratch resistance has been a difficult task.

In particular, a binder containing a fluorine atom has a problem that the binder is easily negatively charged, and when used on the display surface, dust in the environment tends to adhere.
As a technique for imparting dust resistance, it is described that a cationic or anionic material is added. However, when this material is used, there are problems such as separation in the coating solution, unevenness during coating, and deterioration of the scratch resistance of the film.
Further, Non-Patent Document 2 is known to provide a so-called antistatic layer containing conductive particles. This method has a problem that it is necessary to provide a new layer, and equipment and time load during production are large.

  On the other hand, Patent Document 1 describes that the scratch resistance is greatly improved by adding a silane coupling agent to a low refractive index layer material using a fluorine-containing polymer. However, the silane coupling agent having a low boiling point has a problem that it volatilizes in the coating and drying process, and requires an excessive amount of addition considering the volatilized content, and there is a problem that it is difficult to obtain stable performance.

  On the other hand, Non-Patent Document 2 and Patent Document 2 describe that an antifouling layer is overcoated in order to impart antifouling properties. However, these antifouling property-imparting compounds can be coated on a layer containing a hydrolyzed condensate of an organosilane compound as a main binder, but repels on generally used heat and ionizing radiation curable binders. It has problems such as being easy and causing unevenness.

The prior art according to the present invention is as follows.
JP 2003-222704 A JP 2002-277604 A Pigment dispersion technology, surface treatment and use of dispersants and evaluation of dispersibility (published in 1999 by Technical Information Association) Anti-reflective coating characteristics and optimum design / film fabrication technology

  An object of the present invention is to provide an optical film having a low reflectance and excellent scratch resistance and dust resistance. Furthermore, it is providing the optical film excellent in antifouling property. Furthermore, it is providing the polarizing plate and display apparatus which used such an antireflection film.

一般式（ＩＩ）において、Ｒ^１は、水素原子、メチル基、メトキシ基、アルコキシカルボニル基、シアノ基、フッ素原子または塩素原子を表す。Ｙは、単結合、エステル基、アミド基、エーテル基またはウレア基を表す。Ｌは、２価の連結鎖を表す。Ｒ^１０は、置換もしくは無置換のアルキル基、または置換もしくは無置換のアリール基を表す。Ｘは、水酸基または加水分解可能な基を表す。ｎは０または１を表す。Ｘが複数存在するとき、複数のＸはそれぞれ同じであっても異なっていてもよい。
一般式（ＩＶ） Ｃ _n Ｆ _2n+1― （ＣＨ ₂ ） _m― Ｓｉ（Ｒ） ₃
上記式中、ｎは１〜１０の整数、ｍは１〜５の整数を表す。Ｒは炭素数１〜５のアルコキシ基またはハロゲン原子を表す。 As a result of intensive studies, the present inventor has found that the effects of the present invention can be obtained by the following means.
(1) An optical film in which a thin film layer is formed by coating a composition containing fine particles and a binder on a support,
SP value [(B / A) × which is the ratio of the average particle filling rate (B) in the 30% film thickness on the upper layer side opposite to the support to the average particle filling rate (A) in the entire thin film layer 100]] is 105 % or more and 333% or less,
The fine particles are hollow silica particles ;
The surface of the fine particle is treated with a compound represented by the general formula (II) and a compound represented by the general formula ( IV ) that form a covalent bond with the fine particle,
An optical film characterized in that the binder is at least one photopolymerizable compound and contains a monomer having two or more ethylenically unsaturated groups, which is an ester of a polyhydric alcohol and (meth) acrylic acid. .
Formula (II)

In the general formula (II), 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. Y represents a single bond, an ester group, an amide group, an ether group or a urea group. L represents a divalent linking chain. R ¹⁰ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. X represents a hydroxyl group or a hydrolyzable group. n represents 0 or 1. When a plurality of X are present, the plurality of X may be the same or different.
Formula _{(IV) C n F 2n +} 1- (CH 2) m- Si (R) 3
In the above formula, n represents an integer of 1 to 10, and m represents an integer of 1 to 5. R represents an alkoxy group having 1 to 5 carbon atoms or a halogen atom.

(2 ) An optical film obtained by coating an antifouling layer on the optical film according to (1 ) .
( 3 ) The support is a transparent support, and is a multilayer antireflection film in which at least a hard coat layer and a low refractive index layer are laminated on the support (1) or (2) An optical film according to any one of the above.

( 4 ) In the production of the optical film according to any one of (1) to ( 3 ), the coating composition containing the fine particles and the binder is coated with at least two kinds of volatile solvents. A method for producing an optical film.
( 5 ) A polarizing plate comprising the optical film according to any one of (1) to ( 3 ) above.
( 6 ) An image display device comprising the optical film according to any one of (1) to ( 3 ).
The present invention relates to the above (1) to ( 6 ), but other matters are also described for reference.

The optical film of the present invention has a low reflectance, and is excellent in scratch resistance / dust resistance, and further in antifouling properties.
Further, the display device provided with the optical film of the present invention or the polarizing plate using the optical film of the present invention has very high visibility because there is little reflection of external light and reflection of the background.

  Hereinafter, the present invention will be described in detail. In the present specification, when a numerical value represents a physical property value, a characteristic value, etc., the description “(numerical value 1) to (numerical value 2)” means “(numerical value 1) or more and (numerical value 2) or less” .

[Distribution of particles in the layer]
In the optical film of the present invention, a thin film layer is formed by coating a composition containing fine particles and a binder on a support, and the average particle filling rate (A) in the entire thin film layer is as follows. SP value [(B / A) × 100] represented by the ratio of average particle filling rate (B) in 30% film thickness on the upper layer side opposite to the support is 90% or more and 333% or less. To do. The average particle filling rate (A) in the present invention was determined by the following method. The optical film was taken as a section having a thickness of 50 nm, and the cross section was photographed at 150,000 magnifications using five fields of view using a transmission electron microscope. The number of particles was counted over a width 50 times longer than the layer thickness, and the average particle filling rate (A) was calculated as the number of particles per unit area in the thin film layer on the cross-sectional photograph. The average particle filling rate (B) in the 30% film thickness on the upper layer side opposite to the support was also calculated in the same manner as the average particle filling rate (A). Further, for example, when the particles are partially contained in the upper 30% film in the thin film, the number of particles was calculated by multiplying the ratio of the area of the particles contained in the region on the cross-sectional photograph. That is, when 70% of the area of a certain particle is contained in a 30% film thickness on the upper layer side, it is counted as 0.7. In addition, in the case where particles were observed in a cross-sectional photograph of a section having a thickness of 50 nm, the overlapping amount was counted. In this case, the particle distribution in the layer does not have directionality in the layer surface direction, and the average particle filling rate can be obtained based on the count of particles of a specific cross section selected as an intercept.
The SP value range of the present invention is preferably 90 to 333%, more preferably 100 to 333%, and most preferably 150 to 280% from the viewpoint of dustproofness. Cross-sectional schematic diagrams of typical distributions in the thin film layer are shown in FIGS.

In the present invention, in the thin film layer containing the fine particles and the binder, the mass ratio between the fine particles and the total solid content is preferably 2 to 85%, more preferably 5 to 80%, and most preferably 20 to 75%. . If this ratio is too high, the film becomes brittle, and if it is too low, the purpose of containing the original fine particles cannot be exhibited. When the antifouling layer is further provided on the thin film layer of the present invention, the mass ratio of the fine particles to the total solid content is preferably 5 to 80%, most preferably 25% to 75%.
In the present invention, the thickness of the thin film layer is preferably 10 to 5000 nm, more preferably 10 to 500 nm, and most preferably 20 to 300 nm. A preferred layer is a low refractive index layer, and the binder preferably contains a compound containing at least a fluorocarbon or dimethylsiloxane moiety. For example, a coating composition containing a low refractive index binder and low refractive index fine particles is applied, and the low refractive index fine particles are segregated to the upper part by the particle fluidity in the coating film immediately after coating, so that it is originally a separate layer. It is also particularly preferable to perform the application requiring two layers in a single application.

Next, a process for improving the dispersibility of the fine particles in the thin film layer will be described. In the present invention, the fine particles are preferably inorganic fine particles, and particularly preferably inorganic oxide fine particles.
The inorganic oxide fine particles are treated for improving dispersibility by hydrolyzate of organosilane represented by the following general formula (I) and / or a partial condensate thereof. In the treatment for improving dispersibility, it is preferable to use an acid catalyst and / or the following metal chelate compound.
In the dispersibility improving treatment, organosilane, inorganic oxide fine particles, and water as necessary are brought into contact in the presence of at least one of a catalyst having a hydrolysis function and a metal chelate compound having a condensation function. Is done. The organosilane may be partially hydrolyzed or partially condensed. The organosilane undergoes partial condensation subsequent to hydrolysis, which modifies the surface of the inorganic oxide fine particles to improve the dispersibility and obtain a stable dispersion of inorganic oxide fine particles.

Formula (I)
_{^{(R 10) m- Si (X}} ) 4-m
(In the formula, R ¹⁰ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. X represents a hydroxyl group or a hydrolyzable group. M represents an integer of 1 to 3.)
Metal chelate compound An alcohol represented by a general formula R ³ OH (wherein R ³ represents an alkyl group having 1 to 10 carbon atoms) and a general formula R ⁴ COCH ₂ COR ⁵ (wherein R ⁴ is the number of carbon atoms) Zr, Ti, and Al having a ligand of a compound represented by 1 to 10 alkyl groups, R ⁴ represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms. At least one metal chelate compound having a metal selected from

[Organosilane compound]
The organosilane compound used in the present invention will be described in detail.
Formula (I)
(R ¹⁰ ) _m -Si (X) _4-m
In the general formula (I), 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, t-butyl, sec-butyl, hexyl, decyl, hexadecyl and the like. The alkyl group preferably has 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 a phenyl group and a naphthyl group, and a phenyl group is preferable.

X represents a hydroxyl group or a hydrolyzable group. Examples of the hydrolyzable group include an alkoxy group (an alkoxy group having 1 to 5 carbon atoms, such as a methoxy group and an ethoxy group), a halogen atom (for example, Cl, Br, I and the like), and R ^2. COO groups (R ² is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Examples include CH ₃ COO groups and C ₂ H ₅ COO groups), preferably alkoxy groups, particularly preferably. Is a methoxy group or an ethoxy group.
m represents an integer of 1 to 3. When R ¹⁰ or X there are a plurality, a plurality of R ¹⁰ or X groups may be different, even the same, respectively. m is preferably 1 or 2, particularly preferably 1.

The substituent contained in R ₁₀ is not particularly limited, but is a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), hydroxyl group, mercapto group, carboxyl group, epoxy group, alkyl group (methyl group, ethyl group, i -Propyl group, propyl group, t-butyl group etc.), aryl group (phenyl group, naphthyl group etc.), aromatic heterocyclic group (furyl group, pyrazolyl group, pyridyl group etc.), alkoxy group (methoxy group, ethoxy group) , I-propoxy group, hexyloxy group, etc.), aryloxy group (phenoxy group, etc.), alkylthio group (methylthio group, ethylthio group, etc.), arylthio group (phenylthio group, etc.), alkenyl group (vinyl group, 1-propenyl group) ), Acyloxy group (acetoxy group, acryloyloxy group, methacryloyloxy group, etc.), alkoxycarbonyl group (methoxy) Sicarbonyl group, ethoxycarbonyl group, etc.), aryloxycarbonyl group (phenoxycarbonyl group, etc.), carbamoyl group (carbamoyl group, N-methylcarbamoyl group, N, N-dimethylcarbamoyl group, N-methyl-N-octylcarbamoyl group) Etc.), acylamino groups (acetylamino group, benzoylamino group, acrylamino group, methacrylamino group, etc.) and the like, and these substituents may be further substituted. In the present specification, even if a hydrogen atom is replaced by a single atom, it is treated as a substituent for convenience.
When there are a plurality of R ₁₀ , at least one is preferably a substituted alkyl group or a substituted aryl group. Among these, the substituted alkyl group or substituted aryl group preferably further has a vinyl polymerizable group. In this case, the compound represented by the general formula (I) is a vinyl polymerizable compound represented by the following general formula (II). It can be expressed as an organosilane compound having a substituent.

Formula (II)

In the general formula (II), 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. R ¹ is preferably a hydrogen atom, a methyl group, a methoxy group, a methoxycarbonyl group, a cyano group, a fluorine atom or a chlorine atom, more preferably a hydrogen atom, a methyl group, a methoxycarbonyl group, a fluorine atom or a chlorine atom, And methyl groups are particularly preferred.
Y represents a single bond, an ester group, an amide group, an ether group or a urea group. Single bonds, ester groups and amide groups are preferred, single bonds and ester groups are more preferred, and ester groups are particularly preferred.

  L is a divalent linking chain, specifically, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, and a linking group (for example, an ether group, an ester group, an amide group) inside. A substituted or unsubstituted alkylene group, or a substituted or unsubstituted arylene group having a linking group therein, among which a substituted or unsubstituted alkylene group having 2 to 10 carbon atoms, a substituted or unsubstituted carbon number 6 An alkylene group having 3 to 10 carbon atoms having a linking group therein and an unsubstituted alkylene group, an unsubstituted arylene group, and an alkylene group having an ether linking group or an ester linking group therein. An unsubstituted alkylene group and an alkylene group having an ether linking group or an ester linking group therein are 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.

n represents 0 or 1. When there are a plurality of Xs, the plurality of Xs may be the same or different. n is preferably 0.
R ¹⁰ has the same meaning as R ^{10 in} formula (I), preferably a substituted or unsubstituted alkyl group or an unsubstituted aryl group, and more preferably an unsubstituted alkyl group or an unsubstituted aryl group.
X has the same meaning as X in formula (I), preferably a halogen, a hydroxyl group or an unsubstituted alkoxy group, more preferably a chlorine, a hydroxyl group or an unsubstituted alkoxy group having 1 to 6 carbon atoms, a hydroxyl group or a carbon number. 1-3 alkoxy groups are more preferable, and a methoxy group is particularly preferable.

As the organosilane compound used in the present invention, those represented by the following general formula (III) are also preferred.
Formula ^{(III) (Rf-L 1} ) n- Si (R 11) n-4
In the above formula, Rf represents a linear, branched or cyclic fluorinated alkyl group having 1 to 20 carbon atoms or a fluorinated aromatic group having 6 to 14 carbon atoms. Rf is preferably a linear, branched or cyclic fluoroalkyl group having 3 to 10 carbon atoms, and more preferably a linear fluoroalkyl group having 4 to 8 carbon atoms. L ¹ represents a divalent linking group having 10 or less carbon atoms, preferably an alkylene group having 1 to 10 carbon atoms, more preferably an alkylene group having 1 to 5 carbon atoms. The alkylene group is a linear or branched, substituted or unsubstituted alkylene group that may have a linking group (for example, ether, ester, amide) inside. The alkylene group may have a substituent, and preferable substituents in that case include a halogen atom, a hydroxyl group, a mercapto group, a carboxyl group, an epoxy group, an alkyl group, and an aryl group. R ¹¹ represents a hydroxyl group or a hydrolyzable group, preferably an alkoxy group having 1 to 5 carbon atoms or a halogen atom, more preferably a methoxy group, an ethoxy group, or a chlorine atom. n represents an integer of 1 to 3.

Next, among the fluorine-containing silane coupling agent represented by the general formula (III), the fluorine-containing silane coupling agent represented by the following general formula (IV) is preferable.
Formula _{(IV) C n F 2n +} 1- (CH 2) m- Si (R) 3
In the above formula, n represents an integer of 1 to 10, and m represents an integer of 1 to 5. R represents an alkoxy group having 1 to 5 carbon atoms or a halogen atom. n is preferably 4 to 10, m is preferably 1 to 3, and R is preferably a methoxy group, an ethoxy group, or a chlorine atom.

Two or more kinds of the compounds represented by formula (I) may be used in combination.
Specific examples of the compound represented by formula (I) are shown below, but the present invention is not limited thereto.

Among these specific examples, (M-1), (M-2), (M-56), (M-57) and the like are particularly preferable. Further, the compounds of A, B, and C described in Reference Example of Japanese Patent No. 3474330 are also preferable because of excellent dispersion stability. In the present invention, the amount of the organosilane compound represented by the general formula (I) is not particularly limited, but is preferably 1% by mass to 300% by mass, more preferably 3% by mass to the inorganic oxide fine particles. 100% by mass, most preferably 5% by mass to 50% by mass. It is preferably 1 to 300 mol%, more preferably 5 to 300 mol%, and most preferably 10 to 200 mol% per normal concentration (Formol) based on hydroxyl groups on the surface of the inorganic oxide.
When the amount of the organosilane compound used is in the above range, a sufficient stabilizing effect of the dispersion can be obtained, and the film strength is also increased during coating film formation. It is also preferable to use a plurality of types of organosilane compounds in combination, and a plurality of types of compounds can be added simultaneously, or the addition time can be shifted for reaction. Also, it is preferable to add a plurality of types of compounds after making them into partial condensates in advance because the reaction control is easy.

In the present invention, the dispersibility of the inorganic oxide fine particles is improved by causing the hydrolyzate and / or partial condensate thereof to act on the surface of the inorganic oxide fine particles.
In the hydrolysis condensation reaction, 0.3 to 2.0 mol, preferably 0.5 to 1.0 mol of water is added to 1 mol of the hydrolyzable group (X), and the acid catalyst used in the present invention. Or it is preferable to carry out by stirring at 15-100 degreeC in presence of a metal chelate compound.

[Solvent for improving dispersibility]
The dispersibility improvement treatment with the hydrolyzate and / or condensation reaction product of organosilane can be performed in the absence of a solvent or in a solvent. When a solvent is used, the concentration of the hydrolyzate of organosilane and / or the partial condensate thereof can be appropriately determined. As the solvent, an organic solvent is preferably used in order to mix the components uniformly. For example, alcohols, aromatic hydrocarbons, ethers, ketones, esters and the like are preferable.
The solvent is preferably one that dissolves the hydrolyzate and / or condensation reaction product of the organosilane and the catalyst. In addition, it is preferable in the process that an organic solvent is used as a coating solution or a part of the coating solution, and those that do not impair the solubility or dispersibility when mixed with other materials such as a fluorine-containing polymer are preferable.

  Among these, examples of the alcohols include monohydric alcohols and dihydric alcohols. Among these, monohydric alcohols are preferably saturated aliphatic alcohols having 1 to 8 carbon atoms. Specific examples of these alcohols include methanol, ethanol, n-propyl alcohol, i-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, ethylene glycol, diethylene glycol, triethylene glycol, ethylene glycol. Examples thereof include monobutyl ether and ethylene glycol monoethyl ether acetate.

Specific examples of aromatic hydrocarbons include benzene, toluene and xylene, specific examples of ethers include tetrahydrofuran and dioxane, and specific examples of ketones include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Specific examples of esters such as diisobutylketone and the like include ethyl acetate, propyl acetate, butyl acetate, and propylene carbonate.
These organic solvents can be used alone or in combination of two or more. Although the density | concentration of the organosilane compound with respect to the solvent in this process is not specifically limited, Usually, it is the range of 0.1 mass%-70 mass%, Preferably it is the range of 1 mass%-50 mass%.
In the present invention, it is preferable to disperse the inorganic oxide fine particles with an alcohol solvent and then perform a dispersibility improvement treatment, and subsequently replace the dispersion solvent with an aromatic hydrocarbon solvent or a ketone solvent. Substitution with a ketone solvent is preferable from the viewpoint of improving the affinity with the binder used at the time of coating and the stability of the dispersion itself.

[Catalyst for improving dispersibility]
The treatment for improving the dispersibility by the hydrolyzate and / or condensation reaction product of organosilane is preferably performed 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 include organic bases such as pyridine; metal alkoxides such as triisopropoxyaluminum and tetrabutoxyzirconium. From the viewpoint of production stability and storage stability of the inorganic oxide fine particle liquid, an acid catalyst is used in the present invention. (Inorganic acids, organic acids) and / or metal chelate compounds are used. Inorganic acids such as hydrochloric acid and sulfuric acid, and organic acids preferably have an acid dissociation constant (pKa value (25 ° C.)) of 4.5 or less in water, and an acid dissociation constant in hydrochloric acid, sulfuric acid and water of 3.0 or less. More preferred is an organic acid having an acid dissociation constant of 2.5 or less in hydrochloric acid, sulfuric acid and water, more preferred is an organic acid having an acid dissociation constant of 2.5 or less in water, and methanesulfonic acid. Further, oxalic acid, phthalic acid, and malonic acid are more preferable, and oxalic acid is particularly preferable.

  When the hydrolyzable group of the organosilane is an alkoxy group and the acid catalyst is an organic acid, the amount of water added can be reduced because the carboxyl group or sulfo group of the organic acid supplies protons. The amount of water added to 1 mol of the alkoxide group of the organosilane is 0 to 2 mol, preferably 0 to 1.5 mol, more preferably 0 to 1 mol, and particularly preferably 0 to 0.5 mol. Further, when alcohol is used as a solvent, it is also preferable that water is not substantially added.

The amount of the acid catalyst used is 0.01 to 10 mol%, preferably 0.1 to 5 mol%, based on the hydrolyzable group when the acid catalyst is an inorganic acid, and the acid catalyst is an organic acid. However, when water is added, the optimal amount of use is 0.01 to 10 mol%, preferably 0.1 to 5 mol%, based on the hydrolyzable group. When substantially no water is added, it is 1 to 500 mol%, preferably 10 to 200 mol%, more preferably 20 to 200 mol%, still more preferably 50 to 50 mol% with respect to the hydrolyzable group. 150 mol%, particularly preferably 50 to 120 mol%.
The treatment is carried out by stirring at 15 to 100 ° C., but is preferably controlled by the reactivity of organosilane.

[Metal chelate compounds]
The metal chelate compound is an alcohol represented by a general formula R ³ OH (wherein R ³ represents an alkyl group having 1 to 10 carbon atoms) and / or a general formula R ⁴ COCH ₂ COR ⁵ (wherein R ⁴ Is an alkyl group having 1 to 10 carbon atoms, R ⁵ is an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms.) Any metal having a central metal selected from Ti or Al can be suitably used without 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 ³ ) p ¹ (R ⁴ COCHCOR ⁵ ) p ² ,
Ti (OR ³ ) q ¹ (R ⁴ COCHCOR ⁵ ) q ² and Al (OR ³ ) r ¹ (R ⁴ COCHCOR ⁵ ) r ²
Those selected from the group of compounds represented by the formula (1) are preferred, and these act to promote the condensation reaction of the organosilane compound.
R ³ and R ⁴ in the metal chelate compound may be the same or different and each has 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, a sec-butyl group, a t-butyl group, an n-pentyl group, a 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. ^{Further, p 1, p 2, q} 1, q 2 2, r 1 and r ² in the metal chelate compound is an integer which is determined to be 4 or 6-coordinated.

Specific examples of these metal chelate compounds include tri-n-butoxyethylacetoacetate zirconium, di-n-butoxybis (ethylacetoacetate) zirconium, n-butoxytris (ethylacetoacetate) zirconium, tetrakis (n-propylacetate). Zirconium chelate compounds such as acetate) zirconium, tetrakis (acetylacetoacetate) zirconium, tetrakis (ethylacetoacetate) zirconium; diisopropoxy bis (ethylacetoacetate) titanium, diisopropoxy bis (acetylacetate) titanium, diiso Titanium chelate compounds such as propoxy bis (acetylacetone) titanium; diisopropoxyethyl acetoacetate aluminum, diisopropoxy Cetylacetonate aluminum, isopropoxybis (ethylacetoacetate) aluminum, isopropoxybis (acetylacetonate) aluminum, tris (ethylacetoacetate) aluminum, tris (acetylacetonato) aluminum, monoacetylacetonate bis (ethylacetate) And aluminum chelate compounds such as acetate) aluminum.
Among these metal chelate compounds, tri-n-butoxyethyl acetoacetate zirconium, diisopropoxybis (acetylacetonato) titanium, diisopropoxyethyl acetoacetate aluminum, and tris (ethyl acetoacetate) aluminum are preferable. 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.

  The metal chelate compound of the present invention is preferably 0.01 to 50% by mass, more preferably 0.1 to 50%, based on the organosilane, from the viewpoint of the speed of the condensation reaction and the film strength when formed into a coating film. It is used in a proportion of 0.5% by mass, more preferably 0.5 to 10% by mass.

[Dispersion stabilization additive]
In addition to the organosilane, acid catalyst and / or chelate compound, the following component (c) is preferably added to the dispersion or coating composition used in the present invention.
Hereinafter, the component (c) will be further described. The component (c) used in the present invention is a β-diketone compound and / or β-ketoester compound represented by the general formula R ⁴ COCH ₂ COR ⁵ , and is used for the dispersion or coating composition used in the present invention. It acts as a stability improver. That is, by coordinating to a metal atom in the metal chelate compound (zirconium, titanium and / or aluminum compound), the action of promoting the condensation reaction of organosilane and metal chelate component by these metal chelate compounds is suppressed, It is considered that it acts to improve the storage stability of the resulting composition. (C) constituting the component R4 and R5 are the same as R ⁴ and R ⁵ constituting the metal chelate compound.

  Specific examples of the (c) component β-diketone compound and / or β-ketoester compound include acetylacetone, methyl acetoacetate, ethyl acetoacetate, acetoacetate-n-propyl, acetoacetate-i-propyl, acetoacetate- n-butyl, acetoacetate-sec-butyl, acetoacetate-t-butyl, 2,4-hexane-dione, 2,4-heptane-dione, 3,5-heptane-dione, 2,4-octane-dione, Examples include 2,4-nonane-dione, 5-methyl-hexane-dione, and the like. Of these, ethyl acetoacetate and acetylacetone are preferred, and acetylacetone is particularly preferred. These β-diketone compounds and / or β-ketoester compounds may be used alone or in combination of two or more. In the present invention, the β-diketone compound and / or β-ketoester compound as the component (c) is preferably used in an amount of 2 mol or more, more preferably 3 to 20 mol, per 1 mol of the metal chelate compound. If it is less than 2 mol, the storage stability of the resulting composition may be inferior, which is not preferable.

[Inorganic oxide fine particles]
Next, inorganic oxide fine particles that can be used in the present invention will be described.
The inorganic oxide particles are at least one selected from the group consisting of silicon, aluminum, zirconium, titanium, zinc, germanium, indium, tin, antimony and cerium from the viewpoint of the colorlessness of the cured film of the resulting curable composition. Elemental oxide particles are preferred.

  Examples of these inorganic oxide particles include particles of silica, alumina, zirconia, titanium oxide, zinc oxide, germanium oxide, indium oxide, tin oxide, indium tin oxide (ITO), antimony oxide, cerium oxide, and the like. be able to. Of these, particles of silica, alumina, zirconia and antimony oxide are preferred from the viewpoint of high hardness. These may be used alone or in combination of two or more. Furthermore, the inorganic oxide particles are preferably used as an organic solvent dispersion. When used as an organic solvent dispersion, the dispersion medium is preferably an organic solvent from the viewpoint of compatibility with other components and dispersibility. Examples of such an organic solvent include alcohols such as methanol, ethanol, isopropanol, butanol, and octanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ethyl acetate, butyl acetate, ethyl lactate, and γ-butyrolactone. , Esters such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; ethers such as ethylene glycol monomethyl ether and diethylene glycol monobutyl ether; aromatic hydrocarbons such as benzene, toluene and xylene; dimethylformamide, dimethylacetamide, Examples thereof include amides such as N-methylpyrrolidone. Of these, methanol, isopropanol, butanol, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, toluene and xylene are preferred.

  The number average particle diameter of the oxide particles is preferably 1 nm to 2000 nm, more preferably 3 nm to 200 nm, and particularly preferably 5 nm to 100 nm. When the number average particle diameter exceeds 2000 μm, the transparency when cured is reduced, and the surface state when coated is liable to deteriorate. Various surfactants and amines may be added to improve the dispersibility of the particles.

  Examples of products that are commercially available as silicon oxide particle dispersions (for example, silica particles) include colloidal silica, methanol silica sol manufactured by Nissan Chemical Industries, Ltd., MA-ST-MS, IPA-ST, IPA- ST-MS, IPA-ST-L, IPA-ST-ZL, IPA-ST-UP, EG-ST, NPC-ST-30, MEK-ST, MEK-ST-L, MIBK-ST, NBA-ST, XBA-ST, DMAC-ST, ST-UP, ST-OUP, ST-20, ST-40, ST-C, ST-N, ST-O, ST-50, ST-OL, etc. ) Hollow silica CS60-IPA and the like. As powder silica, Aerosil 130, Aerosil 300, Aerosil 380, Aerosil TT600, Aerosil OX50, Silex H31, H32, H51, H52, H121, H122, Asahi Glass Co., Ltd. Examples include E220A and E220 manufactured by Fuji Electric, SYLYSIA470 manufactured by Fuji Silysia Co., Ltd., SG flake manufactured by Nippon Sheet Glass Co., Ltd., and the like.

Moreover, as an aqueous dispersion product of alumina, Nissan Chemical Industries, Ltd. alumina sol-100, -200, -520; As an alumina isopropanol dispersion product, Sumitomo Osaka Cement Co., Ltd. AS-150I; AS-150T manufactured by Sumitomo Osaka Cement Co., Ltd .; HXU-110JC manufactured by Sumitomo Osaka Cement Co., Ltd. as a toluene dispersion of zirconia; Nissan Chemical Industries, Ltd. as an aqueous dispersion of zinc antimonate powder ) Celnax; Alumina, Titanium oxide, Tin oxide, Indium oxide, Zinc oxide, etc. Powder and solvent dispersion products are nanotech made by CI Kasei Co., Ltd .; Antimony-doped tin oxide water dispersion sol is Ishihara Sangyo ( SN-100D, manufactured by Mitsubishi Materials Corporation, and ITO The aqueous dispersion, mention may be made of Taki Chemical Co., Ltd. Nidoraru like.

The oxide particles have a spherical shape, a hollow shape, a porous shape, a rod shape, a plate shape, a fiber shape, or an indefinite shape, preferably a spherical shape or a hollow shape. The hollow silica particles will be described later. The specific surface area of oxide particles (by BET method using nitrogen) is preferably at 10 to 1000 m ² / g, more preferably from 20 to 500 m ² / g, most preferably 50 to 300 m ² / g. These inorganic oxide particles can be obtained by dispersing powder in a dry state in an organic solvent. For example, a dispersion of fine oxide particles known in the art as a solvent dispersion sol of the above oxide is directly used. Can be used.

[Distribution method]
In the present invention, a dispersant may be used to prepare the inorganic oxide fine particles by dispersing them from a powder in a solvent. In the present invention, it is preferable to use a dispersant having an anionic group.
As the anionic group, a group having an acidic proton such as a carboxyl group, a sulfonic acid group (sulfo), a phosphoric acid group (phosphono), a sulfonamide group, or a salt thereof is effective, and in particular, a carboxyl group, a sulfonic acid group, A phosphoric acid group or a salt thereof is preferable, and a carboxyl group and a phosphoric acid group are particularly preferable. A plurality of anionic groups may be contained for the purpose of further improving dispersibility. The average number is preferably 2 or more, more preferably 5 or more, and particularly preferably 10 or more. Moreover, the anionic group contained in a dispersing agent may contain multiple types in 1 molecule.
The dispersant may further contain a crosslinking or polymerizable functional group. Crosslinkable or polymerizable functional groups include ethylenically unsaturated groups (for example, (meth) acryloyl groups, allyl groups, styryl groups, vinyloxy groups, etc.) that can undergo addition reactions and polymerization reactions with radical species, and cationic polymerizable groups (epoxies). Groups, oxatanyl groups, vinyloxy groups, etc.), polycondensation reactive groups (hydrolyzable silyl groups, etc., N-methylol groups) and the like, and functional groups having an ethylenically unsaturated group are preferred.
In the present invention, a disperser can be used to grind inorganic oxide particles. Examples of dispersers include sand grinder mills (eg, pinned bead mills), high speed impeller mills, pebble mills, roller mills, attritors and colloid mills. A sand grinder mill and a high-speed impeller mill are particularly preferred. Further, preliminary dispersion processing may be performed. Examples of the disperser used for the preliminary dispersion treatment include a ball mill, a three-roll mill, a kneader, and an extruder.

[Coating solvent]
The organic oxide dispersion of inorganic oxide fine particles according to the present invention described above is used as a fine particle component and combined with a binder to form a coating composition, and each layer of the optical film can be formed from this composition. Although there is no restriction | limiting in the solvent of a coating composition, It is preferable to contain at least 2 type of volatile solvent. For example, it is preferable to use a combination of at least two selected from alcohol and derivatives thereof, ethers, ketones, hydrocarbons, and esters. A solvent can be selected from the viewpoint of the solubility of the binder component, the stability of the inorganic fine particles, and the adjustment of the viscosity of the coating liquid. By using a combination of two or more solvents, the fine particles can be arranged in the film in a controlled manner so that the SP value and SA value of the present invention are obtained. The boiling point of the solvent used in the present invention is preferably 50 ° C. or higher and 250 ° C. or lower, more preferably 65 ° C. or higher and 200 ° C. or lower. Further, the preferable dielectric constant is preferably 1 or more and 50 or less, more preferably 5 or more and 30 or less at 20 ° C. It is preferable in terms of dispersion stability that a solvent having a dielectric constant of 10 or more is contained in an amount of 10% by mass or more based on the inorganic fine particles.

Although the solvent which can be used for this invention below is mentioned, it is not limited to these.
Alcohol and its derivatives (methanol, ethanol, n-propanol, isopropyl alcohol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec amyl alcohol, 3-pentanol , Tertiary amyl alcohol, n-hexanol, methyl amyl alcohol, 2-ethylbutanol, n-heptanol, 2-heptanol, 3-heptanol, n-octanol, 2-octanol, 2-ethylhexanol, 3,5,5- Trimethylhexanol, nonanol, benzyl alcohol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether, ethylene glycol Diethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol isopropyl ether, ethylene glycol monobutyl ether, ethylene glycol dibutyl ether, ethylene glycol monobutyl ether acetate, ethylene glycol isoamyl ether, methoxymethoxyethanol, methoxypropanol, butoxyethanol, ethylene glycol Monoacetate, ethylene glycol diacetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol Mono butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether)

・ Ethers (isopropyl ether, n-butyl ether, diisoamyl ether, methylphenyl ether, ethylphenyl ether)
Ketones (acetone, methylacetone, methylethylketone, methyl-n-propylketone, methyl-n-butyl, methylisobutylketone, methyl-n-amylketone, methyl-n-hexylketone, diethylketone, ethyl-n-butylketone, Di-n-propyl ketone, diisobutyl ketone, acetonyl acetone, diacetone alcohol, cyclohexanone, methylcyclohexanone)

Hydrocarbons (n-hexane, isohexane, n-heptane, n-octane, isooctane, n-decane, toluene, xylene, ethylbenzene, diethylbenzene, isopropylbenzene, amylbenzene)
Esters (propyl formate, n-butyl formate, isobutyl formate, amyl formate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, n-amyl acetate) , Isoamyl acetate, methyl isoamyl acetate, methoxybutyl acetate, secondary hexyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, methyl cyclohexyl acetate, benzyl acetate, methyl propionate, ethyl propionate , N-butyl propionate, isoamyl propionate, methyl butyrate, ethyl butyrate, n-butyl butyrate, isoamyl butyrate, ethyl oxyisobutyrate, methyl acetoacetate, ethyl acetoacetate, isoamyl isovalerate, methyl lactate, ethyl lactate, Lactic acid-n-butyl, isobutyl lactate, milk -n- amyl lactate, isoamyl, methyl benzoate, diethyl oxalate)

  A particularly preferred combination is the use of at least two, more preferably three, of alcohol and its derivatives, ketones and esters. As preferable examples, for example, two or three of methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 2-methoxypropanol, 2-butoxyethanol, isopropyl alcohol, and toluene can be used in combination.

  In the present invention, in order to control and arrange the inorganic fine particles in the layer, the binder is composed of at least one polymerizable composition having a weight average molecular weight of 5000 or more and at least one polymerizable compound having a weight average molecular weight of less than 5000. It is preferred that Specific examples of the composition having a weight average molecular weight exceeding 5000 are preferably a copolymer having a (meth) acryloyl group in the side chain and a high molecular weight compound containing a fluorocarbon or dimethylsiloxane. Moreover, as a compound with a weight average molecular weight of less than 5000, the polyfunctional acrylate monomer, the partial condensate of the compound of general formula (II) which has a (meth) acryloyl group, etc. are preferable. Detailed compounds are described in the section of film forming binder and low refractive index material.

[Layer structure of optical film]
The optical film of the present invention has a hard coat layer, which will be described later, on a transparent substrate, if necessary, and the refractive index, the film thickness, the number of layers so that the reflectance is reduced by optical interference on the optical film. The layers are stacked in consideration of the layer order. The simplest configuration of the low reflection laminate is a configuration in which only a low refractive index layer is coated on a substrate. In order to further reduce the reflectance, the antireflection layer is preferably constituted by combining a high refractive index layer having a higher refractive index than that of the base material and a low refractive index layer having a lower refractive index than that of the base material. Examples of configurations include two layers of a high refractive index layer / low refractive index layer from the base material side, and three layers having different refractive indices, a medium refractive index layer (having a higher refractive index than the base material or the hard coat layer , A layer having a refractive index lower than that of a high refractive index layer) / a layer having a high refractive index / a layer having a low refractive index, and the like. Especially, it is preferable to apply | coat in order of a middle refractive index layer / high refractive index layer / low refractive index layer on the base material which has a hard-coat layer from durability, an optical characteristic, cost, productivity, etc.

Examples of preferred layer configurations of the low reflection laminate of the present invention are shown below. In the following configuration, the base film refers to a support composed of a film.
・ Base film / low refractive index layer,
・ Base film / Antistatic layer / Low refractive index layer,
・ Base film / Anti-glare layer / Low refractive index layer,
Base film / antiglare layer / antistatic layer / low refractive index layer,
・ Base film / hard coat layer / antiglare layer / low refractive index layer,
・ Base film / hard coat layer / antiglare layer / antistatic layer / low refractive index layer,
・ Base film / hard coat layer / antistatic layer / antiglare layer / low refractive index layer,
・ Base film / hard coat layer / high refractive index layer / low refractive index layer,
・ Base film / hard coat layer / antistatic layer / high refractive index layer / low refractive index layer,
Base film / hard coat layer / medium refractive index layer / high refractive index layer / low refractive index layer,
Base film / antiglare layer / high refractive index layer / low refractive index layer,
Base film / antiglare layer / medium refractive index layer / high refractive index layer / low refractive index layer,
Base film / antistatic layer / hard coat layer / medium refractive index layer / high refractive index layer / low refractive index layer,
Antistatic layer / base film / hard coat layer / medium refractive index layer / high refractive index layer / low refractive index layer,
Base film / antistatic layer / antiglare layer / medium refractive index layer / high refractive index layer / low refractive index layer,
Antistatic layer / base film / antiglare layer / medium refractive index layer / high refractive index layer / low refractive index layer,
Antistatic layer / base film / antiglare layer / high refractive index layer / low refractive index layer / high refractive index layer / low refractive index layer.
The layer configuration is not particularly limited to these layer configurations as long as the reflectance can be reduced by optical interference. The high refractive index layer may be a light diffusing layer having no antiglare property.
The antistatic layer is preferably a layer containing conductive polymer particles or metal oxide fine particles (for example, ATO, ITO), and can be provided by coating or atmospheric pressure plasma treatment. When providing an antifouling layer, it can be provided in the uppermost layer of the above-mentioned configuration.

[Film-forming binder]
In the present invention, it is preferable to use a compound having an ethylenically unsaturated group as a main film-forming binder component of the film-forming composition in terms of film strength, coating solution stability, and coating film productivity. The main film-forming binder refers to one that accounts for 10% by mass or more of the film-forming components excluding inorganic particles. Preferably, they are 20 mass% or more and 100 mass% or less, More preferably, they are 30 mass% or more and 95% or less.
A polymer having a saturated hydrocarbon chain or a polyether chain as a main chain is preferable, and a polymer having a saturated hydrocarbon chain as a main chain is more 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 monomer having two or more ethylenically unsaturated groups include esters of polyhydric alcohol and (meth) acrylic acid (eg, ethylene glycol di (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, di Pentaerythritol hexa (meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3-cyclohexanetetramethacrylate, polyurethane polyacrylate, polyester polymer Acrylate), vinylbenzene and its derivatives (eg, 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1,4-divinylcyclohexanone), vinylsulfone (eg, divinylsulfone), acrylamide (eg, , Methylenebisacrylamide) and methacrylamide. Two or more of these monomers may be used in combination. In the present specification, “(meth) acrylate” represents “acrylate or methacrylate”.

  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 the present invention, an organosilane compound, a hydrolyzate of an organosilane compound and / or a partial condensate thereof from the viewpoints of improving the film strength, enhancing the bondability with other layers, and improving the surface condition when applying an antifouling layer. Is preferably added. Preferred examples of the organosilane compound include the compounds described in the page of the surface treatment of the inorganic compound. The amount of these compounds used is preferably 0.5 to 500% by mass, more preferably 1 to 300% by mass, and most preferably 5 to 100% by mass with respect to the film-forming binder.

  Polymerization of the monomer having an ethylenically unsaturated group can be performed by irradiation with ionizing radiation or heating in the presence of a photo radical initiator or a thermal radical initiator.

  As radical photopolymerization initiators, 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.
Specifically, Examples 1 to 21 described in JP-A No. 2000-80068 are particularly preferable.
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. Specifically, p. 14 to p. 30 in JP-A-58-15503, p. 6 to p. 10 in JP-A 55-77742, No. 1 to No. 8 in p. 287 in JP-B 60-27673, Compounds such as Nos. 1 to 17 of p443 to p444 of JP-A-60-239736 and Nos. 1 to 19 of US-4701399 are particularly preferable.
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.
The polymerization initiator is “Latest UV Curing Technology”, Technical Information Association, 1991, p. 159 and “UV Curing System” written by Kiyotsugu Kato, published by the General Technology Center, 1989, p. 65-148, are useful for 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, etc.), OXE01), etc., and Kayacure (DETX-S, BP-100, BDMK, CTX, BMS, 2-EAQ, ABQ, CPTX, EPD, manufactured by Nippon Kayaku Co., Ltd. , ITX, QTX, BTC, MCA, etc.), Esacure (KIP100F, KB1, EB3, BP, X33, KT046, KT37, KIP150, TZT) manufactured by Sartomer, and combinations thereof are preferable examples.

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 2,2′-azobis (isobutyronitrile), 2,2′-azobis (propionitrile), 1,1′-azobis (cyclohexanecarbonitrile) as azo compounds such as ammonium sulfate and potassium persulfate And diazoaminobenzene, p-nitrobenzenediazonium and the like.

  In the present invention, a polymer having a polyether as a main chain can also be used. A ring-opening polymer of a polyfunctional epoxy compound is preferred. 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.

Instead of or in addition to a monomer having two or more ethylenically unsaturated groups, a monomer having a crosslinkable functional group is used to introduce a crosslinkable functional group into the polymer, and by reaction of this crosslinkable functional group, A crosslinked structure may be introduced into the binder polymer.
Examples of the crosslinkable functional group include isocyanate group, epoxy group, aziridine group, oxazoline group, aldehyde group, carbonyl group, hydrazine group, carboxyl group, methylol group and active methylene group. Vinylsulfonic acid, acid anhydride, cyanoacrylate derivative, melamine, etherified methylol, ester and urethane, and metal alkoxide such as tetramethoxysilane can also be used as a monomer for introducing a crosslinked structure. A functional group that exhibits crosslinkability as a result of the decomposition reaction, such as a block isocyanate group, may be used. That is, in the present invention, the crosslinkable functional group may not react immediately but may exhibit reactivity as a result of decomposition.
These binder polymers having a crosslinkable functional group can form a crosslinked structure by heating after coating.

[Material for low refractive index layer]
As the binder that can be used in the low refractive index layer, those described in the above-mentioned page of the film-forming binder can be used. For example, a fluorine-containing polymer having a low refractive index of the binder itself or a fluorine-containing sol-gel material can be used. It is preferable to use it. The fluorine-containing polymer or fluorine-containing sol-gel is a material that has a dynamic friction coefficient of 0.03 to 0.15 on the surface of the low refractive index layer formed by crosslinking with heat or ionizing radiation and a contact angle of 90 to 120 ° with water. Is preferred.

[Fluoropolymer]
Examples of the fluorine-containing polymer used in the low refractive index layer include hydrolysis and dehydration condensate of perfluoroalkyl group-containing silane compounds (for example, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane). And a fluorine-containing copolymer having a fluorine-containing monomer unit and a structural unit for imparting crosslinking reactivity as structural components.

  Specific examples of the fluorine-containing monomer unit include, for example, fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole, etc.), (meta ) A part of acrylic acid or a fully fluorinated alkyl ester derivative (for example, Biscoat 6FM (manufactured by Osaka Organic Chemical) or M-2020 (manufactured by Daikin)), a complete or partially fluorinated vinyl ether, and the like. From the viewpoint of refractive index, solubility, transparency, availability, etc., hexafluoropropylene is particularly preferred.

Examples of the structural unit for imparting crosslinking reactivity 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 or glycidyl vinyl ether, (B): a carboxyl group, a hydroxy group, an amino group, or a sulfo group A structural unit obtained by polymerization of monomers having, 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 groups (A) and (B) in the molecule and a structural unit of the above (A) and (B). The resulting structural unit (for example, a structural unit that can be synthesized by a technique such as allowing acrylic acid chloride to act on a hydroxyl group),
Is mentioned.

  In the constitutional unit (C), particularly in the present invention, the crosslinkable functional group is preferably a photopolymerizable group. Here, 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 addition to the above-mentioned fluorine-containing monomer units and structural units for imparting crosslinking reactivity, monomers not containing fluorine atoms can be copolymerized as appropriate from the viewpoints of solubility in solvents and film transparency. There are no particular limitations on the monomer units that can be used in combination. For example, olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic esters (methyl acrylate, methyl acrylate, ethyl acrylate, acrylic acid 2) -Ethylhexyl), methacrylates (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, vinyl toluene, α-methylstyrene, etc.), vinyl ethers (methyl) Vinyl ether, ethyl vinyl ether, cyclohexyl vinyl ether, etc.), vinyl esters (vinyl acetate, vinyl propionate, vinyl cinnamate etc.), acrylamides (N-tertbutylacrylamide, N-silane) B hexyl acrylamide), methacrylamides, and acrylonitrile derivatives.

  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-A-2004-45462.

  Moreover, it is preferable that the polysiloxane structure is introduce | transduced in the fluorine-containing polymer of this invention in order to provide antifouling property. There is no limitation on the method for introducing the polysiloxane structure, but for example, as described in JP-A-11-189621, JP-A-11-228631, and JP-A-2000-313709, a polysiloxane block using a silicone macroazo initiator is used. A method of introducing a copolymer component 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 are preferred. These polysiloxane components are preferably 0.5 to 10% by mass, particularly preferably 1 to 5% by mass in the polymer.

  In addition to the above, reactive group-containing polysiloxanes (for example, KF-100T, X-22-169AS, KF-102, X-22-3701IE, X-22-164B, X-22- 5002, X-22-173B, X-22-174D, X-22-167B, X-22-161AS (above trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), AK-5, AK-30, AK-32 (above A product name, manufactured by Toa Gosei Co., Ltd.), Silaplane FM0275, Silaplane FM0721 (manufactured by Chisso), etc.) is also preferred. In addition, silicone compounds described in Tables 2 and 3 of JP-A No. 2003-112383 can also be preferably used. In this case, these polysiloxanes are preferably added in the range of 0.5 to 10% by mass of the total solid content of the low refractive index layer, and particularly preferably 1 to 5% by mass.

  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 coating surface condition and scratch resistance.

  As described in JP-A-10-25388 and JP-A-10-147739, a curing agent may be suitably used in combination with the above polymer. A combination with a compound having a fluorine-containing polyfunctional polymerizable unsaturated group is also preferred as described in JP-A Nos. 2000-17028 and 2002-145952. Preferable examples include the polyfunctional monomers described in the hard coat layer.

[Fluorine-containing silane compounds]
In the low refractive index layer using the hollow silica of the present invention, a hydrolyzate of an organosilane compound having a high affinity for silica and / or a condensate thereof may be used as a binder. Specific examples of the binder include those described in JP-A-2002-79616, JP-A-2002-265866, JP-A-2002-317152, and the like.

[Anti-fouling layer]
In the present invention, it is preferable to provide an antifouling layer as the uppermost layer of the optical film. As the material for the antifouling layer, silicone-containing compounds and fluorine-containing compounds can be used, but organosilane compounds having a fluoroalkyl group at the terminal are preferred. Specific examples of preferred compounds and synthesis methods are described in JP-A-4-338901, JP-B-6-29332, JP-A-7-16940, JP-A-9-61605, JP-A-10-279900, and JP-A-2002-2002. No. 277604, or [Non-Patent Document 2] Characteristics of antireflection film and optimum design / film production technology (issued in 2001 by the Technical Information Association).
It is also preferable to saponify the surface on which the antifouling layer is provided from the viewpoint of improving the surface shape and antifouling durability.

In the present invention, inorganic particles that can be preferably used for the low refractive index layer of the antireflection film will be described.
The coating 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 the appearance such as black tightening and the integrated reflectance are deteriorated. Since the inorganic fine particles are contained in the low refractive index layer, it is desirable that the inorganic fine particles have a low refractive index.
Specifically, inorganic oxide particles or hollow inorganic oxide particles that have been subjected to a treatment for improving the dispersibility dispersed in the organic solvent dispersion described above and that have a low refractive index are preferably used.

Next, hollow silica particles that can be used in the low refractive index layer of the present invention will be described below.
The hollow silica fine particles preferably have a refractive index of 1.15 to 1.40, more preferably 1.17 to 1.35, and most preferably 1.17 to 1.30. The refractive index here represents the refractive index of the entire particle, and does not represent the refractive index of only the outer shell silica forming the hollow silica particles. At this time, if the radius of the cavity in the particle is a and the radius of the particle shell is b, the porosity x expressed by the following formula (VIII) is (Formula VIII)
^{x = (4πa 3/3)} / (4πb 3/3) × 100
Preferably it is 10-60%, More preferably, it is 20-60%, Most preferably, it is 30-60%. If the hollow silica particles are made to have a lower refractive index and a higher porosity, the thickness of the outer shell becomes thinner and the strength of the particles becomes weaker. From the viewpoint of scratch resistance, the low refractive index is less than 1.15. Rate particles are not preferred.
The method for producing hollow silica is described in, for example, JP-A Nos. 2001-233611 and 2002-79616. In particular, particles having cavities inside the shell and having fine pores in the shell are particularly preferred. The refractive index of these hollow silica particles can be calculated by the method described in JP-A No. 2002-79616.

The average particle diameter of the hollow silica is preferably 30% to 150% of the thickness of the low refractive index layer, more preferably 35% to 80%, and still more preferably 40% to 60%. That is, if the thickness of the low refractive index layer is 100 nm, the particle size of the hollow silica is preferably 30 nm to 150 nm, more preferably 35 nm to 100 nm, and still more preferably 40 nm to 65 nm.
If the particle size of the silica particles is too small, the proportion of cavities will decrease and a decrease in refractive index cannot be expected.If it is too large, fine irregularities will be formed on the surface of the low refractive index layer, and the appearance such as black tightening and integrated reflectance will be reduced. Getting worse. The silica fine particles may be either crystalline or amorphous, and monodisperse particles are preferred. The shape is most preferably a spherical diameter, but there is no problem even if the shape is indefinite.
Further, two or more kinds of hollow silica having different particle average particle sizes can be used in combination. Here, the average particle diameter of the hollow silica can be determined from an electron micrograph.
The specific surface area of the hollow silica in the present invention is preferably from 20 to 300 m ² / g, more preferably 30~120m ² / g, most preferably 40~90m ² / g. The surface area can be obtained by the BET method using nitrogen.

In the present invention, silica particles having no voids can be used in combination with hollow silica. The preferred particle size of silica without voids is 30 nm to 150 nm, more preferably 35 nm to 100 nm, and most preferably 40 nm to 80 nm.
In addition, at least one kind of silica fine particles having an average particle size of less than 25% of the thickness of the low refractive index layer (referred to as “silica fine particles with small size particle size”) is used as silica fine particles with the above particle size (“large size particles”). It can also be used in combination with "silica fine particles having a diameter".
Since the fine silica particles having a small size can be present in the gaps between the fine silica particles having a large size, the fine particles can contribute as a retaining agent for the fine silica particles having a large size.
The average particle diameter of the silica fine particles having a small size 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 silica fine particles is preferable in terms of raw material costs and a retaining agent effect.

  Silica fine particles are treated by 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 to the binder component. Chemical surface treatment with a surfactant, a coupling agent, or the like may be performed. A preferred surface treatment method is carried out in accordance with the method described in the above-mentioned surface treatment of inorganic fine particles.

[Material for high refractive index layer]
In the present invention, it is preferable to provide a high refractive index layer. The high refractive index layer can be formed from a binder, mat particles for imparting antiglare properties, and an inorganic filler for increasing the refractive index, preventing crosslinking shrinkage, and increasing the strength.

For the purpose of imparting antiglare properties, the high refractive index layer has a matte particle having an average particle size of 0.1 to 5.0 μm, preferably 1.5 to 3.5 μm, for example, inorganic compound particles. Alternatively, resin particles can be contained. If the difference in refractive index between the matte particles and the binder is too large, the film becomes cloudy, and if it is too small, a sufficient light diffusion effect cannot be obtained, so 0.02 to 0.20 is preferable, and 0.04 to Particularly preferred is 0.10. Similarly to the refractive index, the addition amount of the matting particles with respect to the binder is too large, the film becomes cloudy, and if it is too small, a sufficient light diffusion effect cannot be obtained. A percentage is particularly preferred.
Specific examples of the matting particles include inorganic particles such as silica particles and TiO2 particles; and resin particles such as acrylic particles, crosslinked acrylic particles, polystyrene particles, crosslinked styrene particles, melamine resin particles, and benzoguanamine resin particles. It is done. Of these, crosslinked styrene particles, crosslinked acrylic particles, and silica particles are preferred.
As the shape of the mat particle, either a true sphere or an indefinite shape can be used.

Two or more different kinds of mat particles may be used in combination. When two or more kinds of mat particles are used, the difference in refractive index is 0.0 to effectively exert the refractive index control by mixing the two.
It is preferably 2 or more and 0.10 or less, and particularly preferably 0.03 or more and 0.07 or less. Further, it is possible to impart an antiglare property with mat particles having a larger particle size and to impart another optical characteristic with mat particles having a smaller particle size. For example, when an optical film is attached to a high-definition display of 133 ppi or more, it is required that there is no problem in optical performance called glare. Glare originates from the fact that the pixels are enlarged or reduced due to unevenness existing on the film surface (contributing to anti-glare properties) and lose uniformity of brightness, but with a particle size smaller than that of mat particles that provide anti-glare properties. It can be greatly improved by using mat particles having a different refractive index from the binder.

Furthermore, the particle size distribution of the mat particles is most preferably monodisperse, and the particle sizes of the particles are preferably closer to each other. For example, when a particle having a particle size of 20% or more than the average particle size is defined as a coarse particle, the proportion of the coarse particle is preferably 1% or less, more preferably 0.1% of the total number of particles. Or less, more preferably 0.01% or less. Matt particles having such a particle size distribution are obtained by classification after a normal synthesis reaction, and a matting agent having a more preferable distribution can be obtained by increasing the number of classifications or increasing the degree of classification.

The mat particles are contained in the hard coat layer so that the amount of the mat particles in the formed hard coat layer is preferably 10 to 1000 mg / m ² , more preferably 100 to 700 mg / m ² .
The particle size distribution of the matte particles is measured by a Coulter counter method, and the measured distribution is converted into a particle number distribution.

The hard coat layer has at least one selected from titanium, zirconium, aluminum, indium, zinc, tin, and antimony, in addition to the above mat particles, in order to increase the refractive index of the layer and to reduce cure shrinkage. It is preferable to contain an inorganic filler made of one kind of metal oxide and having an average particle size of 0.2 μm or less, preferably 0.1 μm or less, more preferably 0.06 μm or less.
In order to increase the difference in refractive index from the mat particles, it is also preferable to use a silicon oxide in order to keep the refractive index of the hard coat layer using the high refractive index mat particles low. The preferred particle size is the same as that of the aforementioned inorganic filler.
Specific examples of the inorganic filler used for the hard coat 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 from the viewpoint 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 amount of these inorganic fillers added is preferably 10 to 90% of the total mass of the hard coat layer, more preferably 20 to 80%, and particularly preferably 30 to 70%.
Such a filler does not scatter because the particle size is sufficiently smaller than the wavelength of light, and a dispersion in which the filler is dispersed in a binder polymer behaves as an optically uniform substance.

  The bulk refractive index of the mixture of binder and inorganic filler in the hard coat layer of the present invention is preferably 1.48 to 2.00, more preferably 1.50 to 1.80. In order to make the refractive index within the above range, the kind and amount ratio of the binder and the inorganic filler may be appropriately selected. How to select can be easily known experimentally in advance.

The optical film of the present invention thus formed has a haze value of 3 to 70%, preferably 4 to 60%, and an average reflectance of 450 nm to 650 nm is 3.0% or less, preferably 2.5% or less.
When the optical film of the present invention has a haze value and an average reflectance in the above ranges, good antiglare properties and antireflection properties can be obtained without causing deterioration of the transmitted image.

[Support]
A plastic film is preferably used as the transparent support of the optical film of the present invention. Examples of polymers forming the plastic film include cellulose esters (eg, triacetyl cellulose, diacetyl cellulose, typically TAC-TD80U, TD80UF, etc. manufactured by Fuji Photo Film), polyamides, polycarbonates, polyesters (eg, polyethylene terephthalate, polyethylene). Naphthalate), polystyrene, polyolefin, norbornene resin (Arton: trade name, manufactured by JSR), amorphous polyolefin (ZEONEX: trade name, manufactured by Nippon Zeon), and the like. Of these, triacetyl cellulose, polyethylene terephthalate, and polyethylene naphthalate are preferable, and triacetyl cellulose is particularly preferable. In addition, the cellulose acylate film substantially free of halogenated hydrocarbons such as dichloromethane and the process for producing the same are disclosed in the JIII Journal of Technical Disclosure (Publication No. 2001-1745, published on March 15, 2001; The cellulose acylate described here can also be preferably used in the present invention.

[Saponification]
When the optical film of the present invention is used in a liquid crystal display device, it is disposed on the outermost surface of the display by providing an adhesive layer on one side. When the transparent support is triacetyl cellulose, triacetyl cellulose is used as a protective film for protecting the polarizing layer of the polarizing plate. Therefore, it is preferable in terms of cost to use the optical film of the present invention as it is for the protective film.

When the optical film of the present invention is disposed on the outermost surface of a display by providing an adhesive layer on one side or used as it is as a protective film for a polarizing plate, the optical film on the transparent support is sufficient for adhesion. It is preferable to perform a saponification treatment after forming an outermost layer mainly composed of a fluorine-containing polymer. The saponification treatment is performed by a known method, for example, by immersing the film in an alkali solution for an appropriate time. After being immersed in the alkaline solution, it is preferable to sufficiently wash with water or neutralize the alkaline component by dipping in a dilute acid so that the alkaline component does not remain in the film.
By saponification treatment, the surface of the transparent support opposite to the side having the outermost layer is hydrophilized.
The hydrophilized surface is particularly effective for improving the adhesion with a deflection film containing polyvinyl alcohol as a main component. In addition, the hydrophilic surface makes it difficult for dust in the air to adhere to it, making it difficult for dust to enter between the deflection film and the optical film when bonded to the deflection film, and is effective in preventing point defects due to dust. It is.
The saponification treatment is preferably carried out so that the contact angle of water on the surface of the transparent support opposite to the side having the outermost layer is 40 ° or less. More preferably, it is 30 ° or less, particularly preferably 20 ° or less.

Specific means for the alkali saponification treatment can be selected from the following two means (1) and (2). (1) is superior in that it can be processed in the same process as a general-purpose triacetylcellulose film, but since the surface of the antireflection film is saponified, the surface is alkali-hydrolyzed and the film deteriorates. The point that it becomes dirty when the liquid remains can be a problem. In that case, although it becomes a special process, (2) is excellent.
(1) After the antireflection layer is formed on the transparent support, the back surface of the film is saponified by immersing it in an alkaline solution at least once.
(2) Before or after forming the antireflection layer on the transparent support, an alkaline solution is applied to the surface of the optical film opposite to the surface on which the optical film is formed, and is heated, washed and / or neutralized. Thus, only the back surface of the film is saponified.

[Coating method]
The optical film of the present invention can be formed by the following method, but is not limited to this method.
First, a coating solution containing components for forming each layer is prepared. The coating solution is applied onto a transparent support by dip coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating or extrusion coating (see US Pat. No. 2,681,294). Heat and dry. Among these coating methods, it is preferable to apply the gravure coating method because a coating solution with a small coating amount such as each layer of the antireflection film can be applied with high film thickness uniformity. Among the gravure coating methods, the micro gravure method has a high film thickness uniformity and is more preferable.
In addition, a coating solution with a small coating amount can be applied with high film thickness uniformity even by using a die coating method. Further, since the die coating method is a pre-measuring method, film thickness control is relatively easy, and the solvent in the coating part Is preferred because of less transpiration. Two or more layers may be applied simultaneously. The methods for simultaneous application are described in US Pat. Nos. 2,761,791, 2,941,898, 3,508,947, and 3,526,528 and Yuji Harasaki, Coating Engineering, page 253, Asakura Shoten (1973).

[Polarizer]
The polarizing plate is mainly composed of two protective films that sandwich the polarizing film from both sides. The optical film of the present invention is preferably used for at least one of the two protective films sandwiching the polarizing film from both sides. The manufacturing cost of a polarizing plate can be reduced because the optical film of the present invention also serves as a protective film. In addition, by using the optical film of the present invention as the outermost layer, reflection of external light and the like can be prevented, and a polarizing plate having excellent scratch resistance, antifouling property and the like can be obtained.

As the polarizing film, a known polarizing film or a polarizing film cut out from a long polarizing film whose absorption axis is neither parallel nor perpendicular to the longitudinal direction may be used. A long polarizing film whose absorption axis is neither parallel nor perpendicular to the longitudinal direction is produced by the following method.
That is, a polarizing film stretched by applying tension while holding both ends of a continuously supplied polymer film by a holding means, stretched at least 1.1 to 20.0 times in the film width direction, The progress of the film is such that the difference between the moving speeds in the longitudinal direction of the holding device is within 3%, and the angle formed by the moving direction of the film at the exit of the step of holding both ends of the film and the substantial stretching direction of the film is inclined by 20 to 70 degrees. The film can be produced by a stretching method in which the direction is bent while holding both ends of the film. In particular, those inclined by 45 degrees are preferably used from the viewpoint of productivity.

  The method for stretching the polymer film is described in detail in paragraphs 0020 to 0030 of JP-A-2002-86554.

  When the optical film of the present invention is used as one side of a surface protective film of a polarizing film, twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), in-plane switching (IPS), optically It can be preferably used for a transmissive, reflective, or transflective liquid crystal display device in a mode such as a compensated bend cell (OCB).

The VA mode liquid crystal cell includes (1) a narrowly defined VA mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied, and substantially horizontally when a voltage is applied (Japanese Patent Laid-Open No. Hei 2-). (2) In addition to (2) Liquid crystal cell (SID97, Digest of tech. Papers (Preliminary Collection) 28 (1997) 845 in which the VA mode is converted into a multi-domain (MVA mode) for viewing angle expansion ), (3) A liquid crystal cell in a mode (n-ASM mode) in which rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied and twisted multi-domain alignment is applied when a voltage is applied (Preliminary collections 58-59 of the Japan Liquid Crystal Society) (1998)) and (4) SURVAVAL mode liquid crystal cells (announced at LCD International 98).
For a VA mode liquid crystal cell, a polarizing plate prepared by combining a triacetyl cellulose film stretched biaxially with the optical film of the present invention is preferably used. As for the method for producing a biaxially stretched triacetyl cellulose film, for example, the methods described in JP-A Nos. 2001-249223 and 2003-170492 are preferably used.

  The OCB mode liquid crystal cell is a liquid crystal display device using a bend alignment mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned in a substantially opposite direction (symmetrically) between the upper part and the lower part of the liquid crystal cell. It is disclosed in the specifications of Japanese Patent Nos. 45882525 and 5410422. Since the rod-like liquid crystal molecules are symmetrically aligned at the upper and lower portions of the liquid crystal cell, the bend alignment mode liquid crystal cell has a self-optical compensation function. Therefore, this liquid crystal mode is also called an OCB (Optically Compensatory Bend) liquid crystal mode. The bend alignment mode liquid crystal display device has an advantage of high response speed.

  In an ECB mode liquid crystal cell, rod-like liquid crystal molecules are substantially horizontally aligned when no voltage is applied, and is most frequently used as a color TFT liquid crystal display device, and is described in many documents. For example, it is described in “EL, PDP, LCD display” published by Toray Research Center (2001).

  In particular, for TN mode and IPS mode liquid crystal display devices, as described in JP-A-2001-100043, an optical compensation film having an effect of widening a viewing angle is used as a protective film having two polarizing films on both sides. Among them, by using it on the surface opposite to the optical film of the present invention, a polarizing plate having an antireflection effect and a viewing angle expansion effect can be obtained with the thickness of one polarizing plate, which is particularly preferable.

EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to this. Unless otherwise specified, “part” and “%” are based on mass.
Sample No. 102, 103, 108, 111 , 509 and 510 shall be read as “reference examples”.

(Preparation of sol solution a)
A stirrer, a reactor equipped with a reflux condenser, 120 parts of methyl ethyl ketone, 100 parts of acryloyloxypropyltrimethoxysilane (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.), 3 parts of diisopropoxyaluminum ethyl acetoacetate were added and mixed. Thereafter, 30 parts of ion-exchanged water was added and reacted at 60 ° C. for 4 hours, and then cooled to room temperature to obtain sol solution 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% within the measurement error range. Further, from the gas chromatography analysis, the raw material acryloyloxypropyltrimethoxysilane did not remain at all. Sol solution a was adjusted with methyl ethyl ketone so that the solid content was 29%.

(Preparation of silica dispersion A)
Hollow silica fine particle sol (Isopropyl alcohol silica sol, average particle diameter 40 nm, shell thickness 6 nm, silica concentration 20% by mass, silica particle refractive index 1.30, prepared by changing the size according to Preparation Example 4 of JP-A-2002-79616 ) 500 parts, 8 parts acryloyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.), 2 parts tridecafluorooctyltrimethoxysilane (manufactured by GE Toshiba Silicone Co., Ltd.), and diisopropoxyaluminum ethyl acetate 1 After adding 5 parts and mixing, 9 parts of ion-exchanged water was added. 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 cyclohexanone to 500 g of this dispersion so that the silica content was almost constant, solvent substitution was performed by distillation under reduced pressure at a pressure of 20 kPa. There was no generation of foreign matter in the dispersion, and the viscosity when adjusted to a solid content concentration of 22% by mass with cyclohexanone was 9 mPa · s at 25 ° C. When the residual amount of isopropyl alcohol in the obtained dispersion A was analyzed by gas chromatography, it was 1.0%.

(Preparation of hard coat layer paint (HC-1))
A mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate PETA (manufactured by Nippon Kayaku Co., Ltd.) 50.0 parts by mass, polymerization initiator Irgacure 184 (manufactured by Nippon Ciba Geigy Co., Ltd.) 2.0 parts by mass, the following fluorine A system surface improver (FP-1) 0.30 parts by mass, an organosilane compound KBM-5103 (manufactured by Shin-Etsu Chemical Co., Ltd.) 10.0 parts by mass, and toluene 38.5 parts by mass were added and stirred. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.51.

  Further, a 30% by weight toluene dispersion 1.7 of crosslinked polystyrene particles SX-350 (refractive index 1.60, manufactured by Soken Chemical Co., Ltd.) having an average particle size of 3.5 μm dispersed in this solution at 10,000 rpm with a polytron disperser 1.7. 13.3 parts by mass of a 30% by mass toluene dispersion of a mass part and a crosslinked acrylic-styrene particle having an average particle size of 3.5 μm (refractive index: 1.55, manufactured by Soken Chemical Co., Ltd.) dispersed at 10,000 rpm with a polytron disperser. Part was added and stirred. Subsequently, it filtered with the polypropylene filter with a hole diameter of 30 micrometers, and prepared the coating material (HC-1) for glare-proof hard-coat layers. The refractive index of the coating film made of this paint was 1.51. The surface tension of the obtained antiglare hard coat layer coating material (HC-1) was 32 mN / m.

(Preparation of coating solution for low refractive index layer (Ln-1))
93.0 parts by mass of fluorine-containing copolymer P-3 (weight average molecular weight 50000) described in JP-A-2004-45462, and terminal methacrylate group-containing silicone RMS-033 (Gelest Co., Ltd.) with respect to 200 parts by mass of methyl ethyl ketone 4) parts by mass) and 3 parts by mass of photoradical generator Irgacure OXE01 (manufactured by Ciba Specialty Chemicals) were dissolved. The coating liquid (Ln-1) was prepared by diluting with cyclohexanone and methyl ethyl ketone so that the solid content concentration of the entire coating liquid was 6% by mass and the ratio of cyclohexane and methyl ethyl ketone was 20:80.

(Preparation of coating solution for low refractive index layer (Ln-2))
With respect to 200 parts by mass of methyl ethyl ketone, 54.0 parts by mass of fluorine-containing copolymer P-3 (weight average molecular weight 50000) described in JP-A-2004-45462, terminal methacrylate group-containing silicone RMS-033 (Gelest Co., Ltd.) 4) parts by mass) and 2 parts by mass of the photoradical generator Irgacure OXE01 (Ciba Specialty Chemicals Co., Ltd.) were dissolved. Further, 136.4 parts by mass of silica dispersion A (33 parts by mass as a solid content of hollow silica + surface treatment agent) and 34.5 parts by mass of sol liquid a (10 parts by mass as a solid part) were added and dissolved. A coating solution (Ln-2) was prepared by diluting with cyclohexanone and methyl ethyl ketone so that the solid content concentration of the entire coating solution was 6% by mass and the ratio of cyclohexane and methyl ethyl ketone was 20:80.

(Preparation of coating solution for low refractive index layer (Ln-3))
In preparing the coating liquid for low refractive index layer (Ln-2), instead of silica dispersion A, MEK-ST-L (silica sol, MEK-ST particle size difference, average particle size 45 nm, solid content concentration 30%, A coating solution (Ln-3) was prepared in the same manner except that 106.7 parts by mass (solvent MEK, manufactured by Nissan Chemical Co., Ltd.) was added (33 parts by mass as silica solid content).

(Preparation of coating solution for low refractive index layer (Ln-4))
93.0 parts by mass of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA), 4 parts by mass of a terminal methacrylate group-containing silicone RMS-033 (manufactured by Gelest Co.), 200 parts by mass of methyl ethyl ketone, light 3 parts by mass of radical generator Irgacure OXE01 (manufactured by Ciba Specialty Chemicals Co., Ltd.) was dissolved. A coating solution (Ln-4) was prepared by diluting with cyclohexanone and methyl ethyl ketone so that the solid content concentration of the entire coating solution was 6% by mass and the ratio of cyclohexane and methyl ethyl ketone was 20:80.

(Preparation of coating solution for low refractive index layer (Ln-5))
2200 parts by mass of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA), 4 parts by mass of terminal methacrylate group-containing silicone RMS-033 (manufactured by Gelest Co., Ltd.), 200 parts by mass of methyl ethyl ketone 2 parts by mass of the radical generator Irgacure OXE01 (manufactured by Ciba Specialty Chemicals) was dissolved. Further, 250 parts by mass of silica dispersion A (55 parts by mass as a solid content of hollow silica + surface treatment agent) and 34.5 parts by mass of sol liquid a (10 parts by mass as a solid part) were added and dissolved. The coating liquid (Ln-5) was prepared by diluting with cyclohexanone and methyl ethyl ketone so that the solid content concentration of the entire coating liquid was 6% by mass and the ratio of cyclohexane and methyl ethyl ketone was 20:80.

(Preparation of coating solution for low refractive index layer (Ln-6))
82.0 parts by mass of the fluorine-containing copolymer P-3 (weight average molecular weight 50000) described in JP-A-2004-45462, 200 parts by mass of methyl ethyl ketone, dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate Mixture (DPHA) 15.0 parts by mass, terminal methacrylate group-containing silicone RMS-033 (manufactured by Gelest Co., Ltd.) 4 parts by mass, photoradical generator Irgacure OXE01 (manufactured by Ciba Specialty Chemicals Co., Ltd.) 3 parts by mass Dissolved. The coating liquid (Ln-6) was prepared by diluting with cyclohexanone and methyl ethyl ketone so that the solid content concentration of the entire coating liquid was 6% by mass and the ratio of cyclohexane and methyl ethyl ketone was 20:80.

(Preparation of coating solution for low refractive index layer (Ln-7))
46.0 parts by mass of fluorine-containing copolymer P-3 (weight average molecular weight 50000) described in JP-A-2004-45462, 200 parts by mass of methyl ethyl ketone, dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate 8.0 parts by weight of the mixture (DPHA), 4 parts by weight of the terminal methacrylate group-containing silicone RMS-033 (manufactured by Gelest Co., Ltd.), 2 parts by weight of the photoradical generator Irgacure OXE01 (manufactured by Ciba Specialty Chemicals Co., Ltd.) Dissolved. Further, 136.4 parts by mass of silica dispersion A (33 parts by mass as a solid content of hollow silica + surface treatment agent) and 34.5 parts by mass of sol liquid a (10 parts by mass as a solid part) were added and dissolved. A coating solution (Ln-7) was prepared by diluting with cyclohexanone and methyl ethyl ketone so that the solid content concentration of the entire coating solution was 6% by mass and the ratio of cyclohexane and methyl ethyl ketone was 20:80.

(Preparation of coating solution for low refractive index layer (Ln-8))
In the preparation of the coating solution for low refractive index layer (Ln-7), instead of silica dispersion A, MEK-ST-L (silica sol, MEK-ST particle size difference, average particle size 45 nm, solid content concentration 30%, A coating solution (Ln-8) was prepared in the same manner except that 106.7 parts by mass (solvent MEK, manufactured by Nissan Chemical Co., Ltd.) was added (33 parts by mass as silica solid content).

(Preparation of coating solution for low refractive index layer (Ln-9))
In the preparation of the coating solution for low refractive index layer (Ln-6), instead of the fluorinated copolymer P-3, the fluorinated copolymer P-3 (weight average molecular weight) described in JP-A No. 2004-45462 is used. 51000) was used in the same manner except that the same mass part was used to prepare a coating solution (Ln-9).

(Preparation of coating solution for low refractive index layer (Ln-10))
In the preparation of the coating solution for low refractive index layer (Ln-7), instead of the fluorinated copolymer P-3, the fluorinated copolymer P-3 (weight average molecular weight) described in JP-A No. 2004-45462 is used. A coating solution (Ln-10) was prepared in the same manner except that the same mass part of 51000) was used.

(Preparation of coating solution for low refractive index layer (Ln-11))
In the preparation of the coating solution for low refractive index layer (Ln-10), instead of silica dispersion A, MEK-ST-L (silica sol, MEK-ST particle size difference, average particle size 45 nm, solid content concentration 30%, A coating solution (Ln-11) was prepared in the same manner except that 106.7 parts by mass (solvent MEK, manufactured by Nissan Chemical Co., Ltd.) was added (33 parts by mass as the silica solid content).

(Preparation of antireflection film (101))
On a triacetyl cellulose film “TAC-TD80U” {manufactured by Fuji Photo Film Co., Ltd.} having a thickness of 80 μm and a width of 1340 mm, a hard coat layer coating (HC-1) is applied by a microgravure coating method at a conveyance speed of 30 m / After applying for 150 minutes and drying at 60 ° C. for 150 seconds, using a 160 W / cm air-cooled metal halide lamp {made by Eye Graphics Co., Ltd.) while purging with nitrogen (oxygen concentration 0.5% or less), The coating layer was cured by irradiating with ultraviolet rays having an irradiance of 400 mW / cm ² and an irradiation energy amount of 120 mJ / cm ² to prepare a hard coat layer having an antiglare thickness of 6 μm.

On the hard coat layer thus obtained, a sample 101 was prepared by adjusting the film thickness of the low refractive index layer to 90 nm using the coating liquid for low refractive index layer (Ln-1). . The low refractive index layer was dried at 90 ° C. for 150 seconds, and the ultraviolet curing condition was 240 W / cm air-cooled metal halide lamp (eye graphics The amount of irradiation was 120 mW / cm ² and the irradiation energy amount was 240 mJ / cm ² . The refractive index of the low refractive index layer after curing was 1.44.
Samples 102 to 111 were produced in the same manner as the sample 101 except that the coating solution for the low refractive index layer was changed to (Ln-2) to (Ln-11) for the sample 101 thus obtained. .

(Evaluation of antireflection film)
The obtained film was evaluated for the following items.
(Evaluation 1) Average reflectance After the back surface of the antireflection film was roughened, it was subjected to light absorption treatment with black ink (transmittance at 380 to 780 nm was less than 10%). Using a spectrophotometer (manufactured by JASCO Corporation), the spectral reflectance at an incident angle of 5 ° was measured in a wavelength region of 380 to 780 nm. The average reflectance of 450-650 nm was used for the result.

(Evaluation 2) Bias of particle filling rate in film (SP value)
A 50 nm thick section of each sample was prepared and observed with a transmission electron microscope at 150,000 times, and a photograph was taken. Ratio SP value of average particle filling rate (B) in 30% film thickness of upper layer opposite to support relative to average particle content (A) in all layers of low refractive index layer [(B / A) × 100] was calculated. In the calculation of the particle content in the upper layer 30% film thickness as described above, when a part of the particles were included in the upper layer 30% film, the content rate was calculated by the ratio of the area on the cross-sectional photograph.

(Evaluation 3) Dust-proof evaluation An anti-reflection film was attached to the monitor, and dust (futon, fiber waste from clothes) was sprinkled on the monitor surface. The dust was wiped off with a cleaning cloth, the dust removal property was examined, and the following four grades were evaluated.
○: Dust completely removed by wiping within 3 times.
○ △: Dust can be removed completely, but wiping 4 to 6 times is required.
Δ: Some dust remains after wiping 6 times.
×: Dust remains considerably.

(Evaluation 4) Evaluation of scratch resistance A rubbing test was performed under the following conditions using a rubbing tester.
Evaluation environmental conditions: 25 ° C., 60% RH
Rub material: Steel wool (No. 0000, manufactured by Nippon Steel Wool Co., Ltd.) was wound around the rubbing tip (1 cm × 1 cm) of a tester in contact with the sample, and the band was fixed so as not to move. Then, the reciprocating rubbing motion under the following conditions was given.
Moving distance (one way): 13 cm, rubbing speed: 13 cm / second,
Load: 500 g / cm ³ , tip contact area: 1 cm × 1 cm,
Number of rubs: 10 round trips.
An oil-based black ink was applied to the back side of the rubbed sample and visually observed with reflected light, and scratches on the rubbed portion were evaluated according to the following criteria.
○: Even when viewed very carefully, no scratches are visible.
○ △: Slightly weak scratches are visible when viewed very carefully.
Δ: A weak scratch is visible.
Δ ×: moderate scratches are visible.
X: There are scratches that can be seen at first glance.
The evaluation results are shown in Table 1.

From the results shown in Table 1, the following is clear.
Those containing fine particles and having an SP value in the range of the present invention are excellent in dust resistance and steel wool scratch resistance. Furthermore, it turns out that the fall of a reflectance is recognized by using a hollow silica. Further, it can be seen that these performances are further improved in a sample using a combination of a compound (DPHA, sol liquid a) having an average molecular weight of 5000 or less and a binder (P3, P25) having an average molecular weight of 5000 or more.

A multilayer antireflection film shown below was prepared.
(Preparation of hard coat layer coating solution (HC-2))
The following composition was put into a mixing tank and stirred to obtain a hard coat layer coating solution.
750.0 parts by mass of trimethylolpropane triacrylate (TMPTA, Nippon Kayaku Co., Ltd.), 270.0 parts by mass of poly (glycidyl methacrylate) having a weight average molecular weight of 15000, 730.0 parts by mass of methyl ethyl ketone, 500.0 cyclohexanone Mass parts, 25.0 parts by mass of a cationic photopolymerization initiator (Lordsil 2074) and 50.0 parts by mass of a photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals) were added and stirred.
It filtered with the polypropylene filter with the hole diameter of 0.4 micrometer, and prepared the coating liquid (HC-2) for hard-coat layers.

(Preparation of titanium dioxide fine particle dispersion)
As titanium dioxide fine particles, titanium dioxide fine particles (MPT-129C, manufactured by Ishihara Sangyo Co., Ltd., TiO ₂ : Co ₃ O ₄ : containing cobalt and subjected to surface treatment using aluminum hydroxide and zirconium hydroxide: Al ₂ O ₃ : ZrO ₂ = 90.5: 3.0: 4.0: 0.5 mass ratio) was used.
The following dispersant (41.1 parts by mass) and cyclohexanone (701.8 parts by mass) were added to 257.1 parts by mass of the particles and dispersed by dynomill to prepare a titanium dioxide dispersion having a mass average diameter of 70 nm.

(Preparation of coating solution for medium refractive index layer)
In 99.1 parts by mass of the above titanium dioxide dispersion, 68.0 parts by mass of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA), 3.6 parts by mass of a photopolymerization initiator (Irgacure 907), light A sensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 1.2 parts by mass, 279.6 parts by mass of methyl ethyl ketone and 1049.0 parts by mass of cyclohexanone were added and stirred. After sufficiently stirring, the solution was filtered through a polypropylene filter having a pore size of 0.4 μm to prepare a coating solution for a medium refractive index layer.

(Preparation of coating solution for high refractive index layer)
To 469.8 parts by mass of the above titanium dioxide dispersion, 40.0 parts by mass of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku Co., Ltd.), a photopolymerization initiator (Irgacure 907) 3.3 parts by mass, manufactured by Ciba Specialty Chemicals Co., Ltd., 1.1 parts by mass of photosensitizer (Kayacure-DETX, manufactured by Nippon Kayaku Co., Ltd.), 526.2 parts by mass of methyl ethyl ketone, and cyclohexanone 459 .6 parts by mass was added and stirred. The solution was filtered through a polypropylene filter having a pore size of 0.4 μm to prepare a coating solution for a high refractive index layer.

(Preparation of antireflection film (201))
The hard coat layer coating solution was applied on a triacetyl cellulose film (TD80UF, manufactured by Fuji Photo Film Co., Ltd.) having a thickness of 80 μm using a gravure coater. After drying at 100 ° C., using a 160 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) while purging with nitrogen so that the atmosphere has an oxygen concentration of 1.0 vol% or less, an irradiance of 400 mW / The coated layer was cured by irradiating ultraviolet rays having a cm ² and an irradiation energy amount of 300 mJ / cm ² to form a hard coat layer having a thickness of 8 μm.
On the hard coat layer, a medium refractive index layer coating solution, a high refractive index layer coating solution, and a low refractive index layer coating solution Ln-1 were successively applied using a gravure coater having three coating stations. .

The medium refractive index layer was dried at 90 ° C. for 30 seconds, and the ultraviolet curing condition was 180 W / cm air-cooled metal halide lamp (eye graphics) while purging with nitrogen so that the atmosphere had an oxygen concentration of 1.0% by volume or less. The amount of irradiation was 400 mW / cm ² and the irradiation energy was 400 mJ / cm ² . The medium refractive index layer after curing had a refractive index of 1.630 and a film thickness of 67 nm.

The drying condition of the high refractive index layer is 90 ° C. for 30 seconds, and the ultraviolet curing condition is 240 W / cm air-cooled metal halide lamp (eye graphics The amount of irradiation was 600 mW / cm ² and the amount of irradiation energy was 400 mJ / cm ² .
The cured high refractive index layer had a refractive index of 1.905 and a film thickness of 107 nm.

The low refractive index layer was dried at 90 ° C. for 15 seconds, and the ultraviolet curing condition was 240 W / cm air-cooled metal halide lamp (eye graphics) while purging with nitrogen so that the atmosphere had an oxygen concentration of 0.03% by volume or less. The amount of irradiation was 600 mW / cm ² and the irradiation energy was 600 mJ / cm ² .
The low refractive index layer after curing had a refractive index of 1.44 and a film thickness of 85 nm.

Samples 202 to 211 were produced in the same manner as the sample 201 except that the coating solution for the low refractive index layer was changed to (Ln-2) to (Ln-11) for the sample 201 thus obtained. .
As a result of evaluation according to Example 1, the reflectance of each sample was greatly reduced by providing the middle refractive index layer and the high refractive index layer. The low refractive index layer containing the inorganic fine particles exhibits an SP value in the range specified in the present invention, and it was found that according to the present invention, an antireflection film having low reflection and excellent dust resistance and scratch resistance can be obtained.

(Preparation of hard coat layer coating solution (HC-3))
Desolite Z7404 (zirconia fine particle-containing hard coat composition, manufactured by JSR Corporation) 100 parts by mass, DPHA (UV curable resin, manufactured by Nippon Kayaku Co., Ltd.) 31 parts by mass, KBM-5103 (silane coupling agent, Shin-Etsu) Chemical Industry Co., Ltd.) 10 parts by mass, KE-P150 (1.5 μm silica particles, Nippon Shokubai Co., Ltd.) 8.9 parts by mass, MXS-300 (3 μm crosslinked PMMA particles, manufactured by Soken Chemical Co., Ltd.) 3.4 parts by mass, MEK 29 parts by mass and MIBK 13 parts by mass were charged into a mixing tank and stirred to prepare a hard coat layer coating solution.

(Preparation of antireflection film)
A triacetyl cellulose film (TD80U, manufactured by Fuji Photo Film Co., Ltd.) as a support is unrolled in a roll form, and the above coating liquid for hard coat layer has a diameter of 135 lines / inch and a gravure pattern with a depth of 60 μm. Using a 50 mm micro gravure roll and a doctor blade, the coating was carried out under conditions of a conveyance speed of 10 m / min, dried at 60 ° C. for 150 seconds, and further under a nitrogen purge, an air-cooled metal halide lamp (Igraphics Corporation) )), The coating layer was cured by irradiating with ultraviolet rays having an irradiance of 400 mW / cm ² and an irradiation energy amount of 250 mJ / cm ² to form a hard coat layer and wound up. The hard coat 301 was produced by adjusting the rotation speed of the gravure roll so that the thickness of the hard coat layer after curing was 4.0 μm. The surface roughness of the hard coat layer 301 thus obtained was Ra = 0.02 μm, RMS = 0.03 μm, Rz = 0.25 μm (Ra (center line average roughness), RMS (root mean square roughness), Rz (n-point average roughness) was measured with a scanning probe microscope system SPI3800, manufactured by Seiko Instruments Inc.).

  On the hard coat 301, the coating solutions (Ln-1) to (Ln-11) for the low refractive index layer of Example 1 were applied and cured to prepare samples 301 to 311. An antireflection film sample was prepared by performing the following saponification treatment and processing a polarizing plate. As a result of evaluating these samples according to Example 1, it was found that according to the present invention, an antireflection film having low reflection and excellent dust resistance and scratch resistance can be obtained.

(Saponification treatment of antireflection film)
A 1.5 mol / l aqueous sodium hydroxide solution was prepared and kept at 55 ° C. A 0.005 mol / lN dilute sulfuric acid aqueous solution was prepared and kept at 35 ° C. The prepared antireflection film was immersed in the aqueous sodium hydroxide solution for 2 minutes, and then immersed in water to sufficiently wash away the aqueous sodium hydroxide solution. Subsequently, after being immersed in the above-mentioned dilute sulfuric acid aqueous solution for 1 minute, it was immersed in water to sufficiently wash away the dilute sulfuric acid aqueous solution. Finally, the sample was thoroughly dried at 120 ° C.
In this way, a saponified antireflection film was produced.

(Preparation of polarizing plate with antireflection film)
A polarizing film was prepared by adsorbing iodine to a stretched polyvinyl alcohol film. A saponified antireflection film was attached to one side of the polarizing film using a polyvinyl alcohol adhesive so that the support side (triacetyl cellulose) of the antireflection film was the polarizing film side. Further, the disc surface of the discotic structural unit is inclined with respect to the transparent support surface, and the angle formed by the disc surface of the discotic structural unit and the transparent support surface changes in the depth direction of the optical anisotropic layer. The viewing angle widening film (Wide View Film SA, manufactured by Fuji Photo Film Co., Ltd.) having the optical compensation layer is saponified and attached to the other side of the polarizing film using a polyvinyl alcohol adhesive. . In this way, an antireflection polarizing plate was produced.

(Preparation of hard coat layer coating solution (HC-4))
90 parts by mass of MEK, 10 parts by mass of cyclohexanone, 85 parts by mass of partially caprolactone-modified polyfunctional acrylate (DPCA-20, manufactured by Nippon Kayaku Co., Ltd.), KBM-5103 (silane coupling agent: Shin-Etsu Chemical Co., Ltd.) 10 parts by mass) and 5 parts by mass of a photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) were added and stirred. A hard coat layer coating solution (HC-4) was prepared by filtration through a polypropylene filter having a pore size of 0.4 μm.

(Preparation and evaluation of antireflection film)
The coating liquid HC-4 for hard coat layer was applied and cured according to Example 3 on a triacetyl cellulose film as a support. At that time, the hard coat 401 was prepared by adjusting the rotation speed of the gravure roll so that the thickness of the hard coat layer after curing was 4.5 μm.
The coating liquids (Ln-1) to (Ln-11) of Example 1 were applied and cured on the hard coat 401 to prepare samples 401 to 411. These samples were subjected to a saponification treatment as described in Example 3 to prepare polarizing plates. As a result of evaluating these polarizing plate samples according to Example 1, it was found that according to the present invention, an antireflection film having low reflection and excellent dust resistance and scratch resistance can be obtained.

(Preparation of antireflection film (501))
On a sample 104 of Example 1, an antifouling layer coating solution _{(C 3 F 7 - (OC} 3 F 6) 24 -O- (CF 2) 2 -C 2 H 4 -O-CH 2 Si (OCH ₃ ) The perfluoropolyether group-containing silane coupling agent consisting of ₃ was diluted with perfluorohexane to 0.5% by mass). A coating film was formed by drying at 120 ° C. for 1 minute. The coating amount was set so that the theoretical coating amount after drying was 5 nm on the assumption that the coating was uniformly performed.

(Preparation of antireflection film (502))
The saponification treatment described in Example 3 was performed on the sample 104 of Example 1. On the sample after saponification treatment, the antifouling layer coating solution was applied and dried in the same manner as in the antireflection film (501) to prepare an antireflection film (502).

(Preparation of antireflection films (503) to (510))
Samples that were not subjected to saponification treatment on samples 105, 109, 110, and 111 of Example 1 were prepared. The antifouling layer coating solution was applied and dried on each of them in the same manner as the antireflection film 501 to prepare antireflection films (503) to (510).

Each antireflection film was evaluated as follows.
(Evaluation 5) Evaluation of coating surface condition After the back surface of the antireflection film was roughened, it was subjected to light absorption treatment with black ink (transmittance at 380 to 780 nm was less than 10%). The surface condition of the coated surface of the sample before and after the application of the antifouling layer was evaluated according to the following criteria.
○: No difference is observed between before and after applying the antifouling layer.
Δ: A slight difference is observed before and after application of the antifouling layer, but there is no problem in practical use.
Δ: A difference is observed before and after application of the antifouling layer.
X: A difference was observed before and after application of the antifouling layer, and whiteness increased.

(Evaluation 6) Antifouling Evaluation Magic Ink No. A 700 cm (M700-T1 black) extra fine was used to draw a circle with a diameter of 1 cm on the sample. After being allowed to stand for 24 hours, it was rubbed with Bencot (manufactured by Asahi Kasei Co., Ltd.) to evaluate whether the magic could be wiped off according to the following criteria.
○: Even if you look very carefully, you can not see any magic marks.
Δ: A slight trace of magic is visible.
X: A trace that does not disappear is detected.
Evaluation environmental conditions: 25 ° C., 60% RH
The results are shown in Table 2 together with the results of the samples not coated with the antifouling layer.

  From the results shown in Table 2, it can be seen that the sample including the inorganic fine particles and having the antifouling layer on the sample satisfying the SP value in the range defined by the present invention is excellent in the coated surface state and antifouling property. In addition, a saponification treatment is applied before applying the antifouling layer, and the effect of improving the coated surface shape is observed (comparison between samples 509 and 510).

It is an example of the thin film layer of the optical film of this invention. It is an example of the thin film layer of the optical film of this invention. It is an example of the thin film layer of the optical film for a comparison.

Explanation of symbols

  1 Fine particles

Claims (6)

An optical film in which a thin film layer is formed by coating a composition containing fine particles and a binder on a support,
SP value [(B / A) × which is the ratio of the average particle filling rate (B) in the 30% film thickness on the upper layer side opposite to the support to the average particle filling rate (A) in the entire thin film layer 100]] is 105 % or more and 333% or less,
The fine particles are hollow silica particles ;
The surface of the fine particle is treated with a compound represented by the general formula (II) and a compound represented by the general formula ( IV ) that form a covalent bond with the fine particle,
An optical film characterized in that the binder is at least one photopolymerizable compound and contains a monomer having two or more ethylenically unsaturated groups, which is an ester of a polyhydric alcohol and (meth) acrylic acid. .
Formula (II)

In the general formula (II), 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. Y represents a single bond, an ester group, an amide group, an ether group or a urea group. L represents a divalent linking chain. R ¹⁰ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. X represents a hydroxyl group or a hydrolyzable group. n represents 0 or 1. When a plurality of X are present, the plurality of X may be the same or different.
Formula _{(IV) C n F 2n +} 1- (CH 2) m- Si (R) 3
In the above formula, n represents an integer of 1 to 10, and m represents an integer of 1 to 5. R represents an alkoxy group having 1 to 5 carbon atoms or a halogen atom. An optical film obtained by coating an antifouling layer on the optical film according to claim 1 . 3. The optical film according to claim 1, wherein the support is a transparent support, and at least a hard coat layer and a low refractive index layer are laminated on the support. . The optical film according to any one of claims 1 to 3 , wherein at least two kinds of volatile solvents are contained in the coating composition containing fine particles and a binder, and the optical film is coated. A method for producing a film. A polarizing plate comprising the optical film according to any one of claims 1-3. It has an optical film as described in any one of Claims 1-3 , The image display apparatus characterized by the above-mentioned.

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