JP2006096861A - Coating composition, optically functional layer, antireflection film, polarization plate and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating composition forming a uniform flat layer having a low refractive index without spoiling characteristics of the layer having the low refractive index of an antireflection film, an optically functional layer and the antireflection film using the coating composition, a polarization plate using the antireflection film and an image display device having the film or the polarization plate. <P>SOLUTION: The coating composition comprises (A) a compound polymerizable by heat or active energy irradiation, (B) a viscosity modifier and (C) a solvent, and forms a transparent film having ≤1.50 refractive index after curing and ≤2% haze when forming a film having 100 nm thickness. The optically functional layer and the antireflection film formed from the coating composition, the polarizing plate using the antireflection film and the image display device installed with these films of the polarization plate are also provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a coating composition for an optical functional layer, an optical functional layer, a method for producing the optical functional layer, an antireflection film, an optical functional layer, a polarizing plate using the antireflection film, and the optical functional layer and the antireflection film. The present invention also relates to an image display device and a liquid crystal display device using the polarizing plate.

  An antireflection film as an optical functional film is generally used to reflect external light 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 contrast degradation and image reflection due to the optical interference, 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 can be generally produced by forming a low refractive index layer with a film thickness of about 100 nm on the outermost layer of the film. A material having a refractive index as low as possible is desired for the low refractive index layer. In addition, since the antireflective film is used on the outermost surface of the display, the low refractive index layer, which is the outermost layer, requires not only the refractive index but also the characteristics of the film itself, such as high scratch resistance, antifouling properties and transparency. Many need to satisfy the characteristics.

  In recent years, with the trend toward thinner and larger displays, antireflection films have been required to have a uniform surface with a wider area. Conventionally, as a method of forming a low refractive index layer, a metal oxide film is formed by a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method, particularly a vacuum vapor deposition method or a sputtering method which is a kind of physical vapor deposition method. Has been done.

  However, a method for forming a transparent thin film of metal oxide by vapor deposition or sputtering is not suitable for mass production because of low productivity, and a wet film forming method with high productivity, particularly a method of forming by a coating method has been proposed.

  In general, after applying a coating composition consisting of a diluting solvent to a base material that is continuously transported, a solvent is removed by drying and cured by heat or active energy ray irradiation. This is a method of forming a film.

  With respect to the antireflection film, an improvement in productivity is required from the viewpoint of cost reduction, and an increase in coating speed is an essential technique. However, increasing the coating speed tends to cause film thickness unevenness due to accompanying air or drying air, and it becomes difficult to maintain the surface uniformity required for the antireflection film. The surface uniformity referred to here means that variations in optical performance, such as antireflection performance, and variations in film physical properties such as scratch resistance, and variations in reflection color by visual observation are small within the entire display area of the display. Say.

  In particular, since the low refractive index layer has a very thin dry film, a solid content concentration of the coating composition is low, and generally a solution having a low viscosity is used. When the viscosity is low, there is a problem that it is easily affected by the above-mentioned drying wind, and wind unevenness is likely to occur as the coating speed increases.

  In addition, if the viscosity is low, the coating thickness is likely to fluctuate due to disturbances such as device vibration during application. In order to form a low refractive index layer uniformly at high speed by the application method, the coating composition There is preferably a method of increasing the viscosity of the product to an appropriate viscosity.

  As a method for adjusting the viscosity, it is possible to use selection of a solvent composition, type of resin contained in the coating composition, molecular weight, and the like. However, when the solvent composition is changed, the drying speed, the dissolution of the resin, the dispersion state of the inorganic fine particles, and the like may change. Also, changing the type of resin, molecular weight, etc. may cause problems due to changes in the synthesis process, coating properties, stability of the coating composition over time, and the like. Therefore, it is preferable to have a method capable of adjusting the viscosity by independently adding a viscosity modifier.

  However, the low refractive index layer has a low solid content concentration, and when a viscosity modifier is added, the content of the viscosity modifier in the dry film increases, and various properties required for the low refractive index layer change greatly. Therefore, it was difficult to put it into practical use.

  In order to form a low refractive index layer at high speed, the coating method is also very important. As the coating method of the antireflection film, dip coating, micro gravure, reverse roll coating, etc. have been mainly used so far.

  However, in the dip coating method, vibration of the coating liquid in the liquid receiving tank is unavoidable, and stepped unevenness is likely to occur. Further, in the reverse roll coating method and the micro gravure method, stepped unevenness is likely to occur due to roll eccentricity and deflection related to coating. Furthermore, in the microgravure method, coating amount unevenness is likely to occur due to the production accuracy of the gravure roll and the temporal change of the roll and blade due to the contact between the blade and the gravure roll.

  Further, since these coating methods are post-measuring methods, it is relatively difficult to ensure a stable film thickness. Therefore, in these coating methods, it is difficult to increase the coating speed beyond a certain speed, and although the productivity is higher than the vapor deposition method or the like, the high productivity inherent in coating cannot be fully utilized.

  On the other hand, since the die coating method of Patent Document 1 is a pre-measuring coating method, it has an advantage of high film thickness stability. However, since coating is performed using a generally used die configuration, it is possible to realize only high speed comparable to the above-described various coating methods. Specifically, in a thin layer coating such as an antireflection layer, film thickness unevenness occurs in a direction perpendicular to and parallel to the transport direction of the transparent support, and it is difficult to maintain film thickness stability. .

  On the other hand, in the above-described die coating methods of Patent Documents 2 and 3, a thin layer can be applied with high accuracy by devising the configuration of the die. Therefore, by using this method, a thin layer such as an antireflection layer can be applied with high accuracy. However, depending on the type of liquid, it was difficult to apply at high speed, and sometimes it was impossible to apply itself.

  In particular, as described above, when the viscosity of the coating composition is increased, the coating limit speed of the coating film when the transport speed of the base during coating is increased may cause a problem.

The viscosity modifier is described in Non-Patent Documents 1 and 2, but no effective usage has been proposed for the low refractive index layer.
The thixotropy-imparting agent is described in Patent Documents 4 and 5, which are contents related to the antiglare layer having a thickness greater than that of the low refractive index layer, and are specific proposals for use in the low refractive index layer. Has not been made.

JP 7-151904 A JP 2003-200097 A JP 2003-211052 A JP-A-10-219136 JP 2002-196112 A Progress in coating technology General Technology Center Co., Ltd. Viscosity Adjustment Technology Technical Information Association

The present invention has been made in view of such circumstances, and a coating composition and a manufacturing method for manufacturing an antireflection film having productivity higher than that of a vapor deposition method and other coating methods and having high film thickness uniformity. The purpose is to provide. Another object of the present invention is to provide the coating composition, the optical functional layer prepared by the production method, and the antireflection film.
Another object of the present invention is to provide a polarizing plate using the antireflection film.
Still another object of the present invention is to provide an image display device comprising the antireflection film or the polarizing plate.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have added the viscosity modifier having specific characteristics to the coating composition used for coating, and the above-mentioned object by using a specific coating method. It has been found that it can be achieved, and the present invention has been completed.
That is, the object of the present invention is achieved by the following coating composition, optical functional layer, antireflection film, production method, polarizing plate, and image display device.

(1) (A) a film polymerizable by irradiation with heat or active energy rays, (B) a viscosity modifier and (C) a solvent, having a refractive index after curing of 1.50 or less, and a film having a thickness of 100 nm A coating composition capable of forming a transparent film having a haze of 2% or less when formed.
(2) (D) The coating composition as described in (1) above, which contains inorganic fine particles having an average particle diameter of 100 nm or less.
(3) The coating composition as described in (1) or (2) above, wherein the inorganic fine particles are hollow particles.
(4) The coating composition according to any one of (1) to (3) above, wherein the solid content concentration is 10% by mass or less.
(5) The coating composition according to any one of (1) to (4) above, wherein the content of the viscosity modifier (B) relative to the total solid content is 30% by mass or less.
(6) (B) The viscosity when the viscosity modifier is not added is 5 mPa · s (cp) or less, and even when the viscosity modifier is added at 5 mass% or less with respect to the total amount of the coating solution, the viscosity measured with the vibration viscometer is The coating composition according to any one of the above (1) to (5), which is increased by 1.3 times or more as compared to before addition.
(7) The coating composition according to any one of the above (1) to (6), wherein the refractive index of the coated film after curing does not increase by 0.05 or more due to the addition of the viscosity modifier (B).
(8) The water contact angle of the transparent film after curing is 90 ° or more, and (B) the water contact angle decrease due to the addition of the viscosity modifier is 5 ° or less, (1) to (7) ).
(9) The coating composition as described in any one of (1) to (8) above, wherein the viscosity modifier (B) has thixotropic properties.
(10) The coating composition as described in any one of (1) to (9) above, wherein the compound polymerizable by (A) heat or active energy ray irradiation is a fluorine-containing compound.
(11) The coating composition as described in any one of (1) to (10) above, wherein the solvent (C) comprises a ketone solvent.
(12) The coating composition as described in any one of (1) to (11) above, wherein an inorganic layered compound subjected to an organic treatment is dispersed as a viscosity modifier.
(13) The coating composition as described in (12) above, wherein the inorganic layered compound is synthetic smectite.
(14) The coating composition according to claim 12 or 13, wherein the organic treatment agent is represented by the following general formula (1).
General formula (1)
(N (R _a ) _4-n (R _b ) _n ) ⁺ A ⁻
In the formula, Ra is represented by (CH ₂ ) _m H or (CH ₂ ) _m R _c H or (CH ₂ Rc) _m H, m is an integer of 2 or more, and R _c may have any structure or may be absent. , R _b represents CH ₃ , and n represents 0 or an integer of 1 to 3. A ⁻ represents Cl ⁻ or Br ⁻ .
(15) The coating composition as described in any one of (12) to (14) above, wherein the average particle size after dispersion of the inorganic stratiform compound is 200 nm or less.
(16) The coating composition as described in any one of (1) to (11) above, wherein the (B) viscosity modifier is a polymer having no polymerizable group having a molecular weight of 100,000 or more.

(17) A film obtained by applying the coating composition according to any one of (1) to (16) above on a transparent substrate, removing the solvent by drying, and curing by heat or active energy ray irradiation. An optical functional layer characterized by being a layer having a thickness of 200 nm or less.
(18) The optical functional layer as described in (17) above, containing 30% by mass or less of the viscosity modifier defined in any one of (12) to (16) above.
(19) The optical functional layer as described in (17) or (18) above, wherein the refractive index is 1.45 or less.

(20) A hard coat layer containing resin beads is formed on a transparent support, and the optical functional layer according to any one of (17) to (19) is formed thereon. Antireflection film.
(21) The hard coat layer containing resin beads is formed by dispersing at least one kind of light-transmitting particles having an average particle diameter of 0.5 to 5 μm in a light-transmitting resin. (20), wherein the difference in refractive index from the resin is 0.02 to 0.2, and the translucent particles are contained in an amount of 3 to 30% by mass of the total solid content of the light scattering layer. The antireflection film as described in 1.
(22) An antireflective film having two or more thin film layers having a refractive index of 200 nm or less on a transparent support, wherein the low refractive index layer located on one surface of the transparent support is the above (17 ) To (19), wherein at least one high refractive index layer having a higher refractive index than that of the low refractive index layer is provided between the transparent support and the low refractive index layer. The low refractive index layer and the high refractive index layer both contain inorganic fine particles, and the average reflectance at a wavelength of 450 nm to 650 nm of the specular reflectance at 5 degrees is 1% or less. Anti-reflection film.
(23) The color of the specularly reflected light with respect to 5 ° incident light of the CIE standard light source D65 in the wavelength region of 380 nm to 780 nm indicates that the a ^* and b ^* values of the CIE1976L ^* a ^* b ^* color space are −8 ≦ a ^*, respectively ^. The antireflection film according to claim 20, which is in a range of ≦ 8 and −10 ≦ b ^* ≦ 10.

(24) After the land of the tip lip of the slot die is brought close to the surface of the web supported continuously by the backup roll and the coating composition is applied from the slot of the tip lip, the solvent is dried. An optical functional layer according to any one of (17) to (19) is formed by a method of curing with ionizing radiation or heat.
(25) When a slot die having a land length in the web traveling direction of the tip lip on the web traveling direction side of the slot die of 30 μm or more and 100 μm or less is used and the slot die is set at a coating position, The gap between the tip lip and the web opposite to the traveling direction is applied by using a coating apparatus installed so that the gap between the tip lip and the web on the web traveling direction side is 30 μm or more and 120 μm or less. The method for producing an optical functional layer as described in (24) above, wherein
(26) The method for producing an optical functional layer as described in (24) or (25) above, wherein the web conveyance speed during coating is 20 m / min or more.

(27) A polarizing plate in which two surface protective films are bonded to the front and back surfaces of a polarizer, and the antireflection film according to any one of the above (20) to (23) is applied to at least one surface protective film. A polarizing plate characterized by being used.
(28) The surface protective film itself located on the surface opposite to the surface to which the antireflection film as the surface protective film of the polarizing plate is bonded, and the position between the surface protective film and the polarizer. The polarizing plate as described in (27) above, wherein at least one of the films is an optical compensation film.
(29) An image display device having at least one of the antireflection film according to any one of (20) to (23) or the polarizing plate according to (27) or (28).
(30) A TN, STN, VA, IPS, or OCB mode transmissive, reflective, or transflective liquid crystal display device having at least one polarizing plate according to (27) or (28).

  The antireflection film of the present invention has a sufficient antireflection property, antifouling property, and scratch resistance, and is excellent in surface shape, has little unevenness, is excellent in coating suitability, and has high productivity. Furthermore, the image display device provided with the antireflection film and the image display device provided with the polarizing plate using the antireflection film of the present invention have little reflection of external light and reflection of the background, and no color unevenness. Very high visibility.

As an embodiment of the present invention, a basic configuration of an antireflection film which is a preferred embodiment of the optical functional film of the present invention will be described with reference to the drawings. In the present specification, the description “(numerical value 1) to (numerical value 2)” means “(numerical value 1) or more and (numerical value 2) or less”.
The cross-sectional view schematically shown in FIG. 1A is an example of the antireflection film of the present invention. The antireflection film 1 includes a transparent support 2, three types of functional layers (a hard coat layer 3, an antiglare layer). Layer structure of the functional hard coat layer 4 and the low refractive index layer 5). As the antiglare hard coat layer 4, mat particles 6 are dispersed in a translucent resin, and the refractive index of the material other than the mat particles 6 of the antiglare hard coat layer 4 is 1.50-2. The refractive index of the low refractive index layer 5 is preferably in the range of 1.35 to 1.49. The average particle diameter of at least one kind of matte particles is 0.5 to 5 μm, the difference in refractive index between the translucent particles and the translucent resin is 0.02 to 0.2, and It is desirable that the light particles are contained in an amount of 3 to 30% by mass based on the total solid content of the light scattering layer. In the present invention, the functional layer may be a hard coat layer having an antiglare property as described above, a hard coat layer not having an antiglare property, a light diffusion layer, a single layer, a plurality of layers, For example, it may be composed of 2 to 4 layers. When there is a hard coat layer having antiglare properties, the hard coat layer may not be provided as another layer. The low refractive index layer which is a functional layer is coated on the outermost layer.
Further, the low refractive index layer preferably satisfies the following formula (VII) from the viewpoint of reducing the reflectance.
Formula (VII)
(M / 4) × 0.7 <n ₁ d ₁ <(m / 4) × 1.3
In the formula, m is a positive odd number, n ₁ is the refractive index of the low refractive index layer, and d ₁ is the film thickness (nm) of the low refractive index layer. Further, λ is a wavelength, which is a value in the range of 500 to 550 nm.
In addition, satisfy | filling said numerical formula (VII) means that m (positive odd number, usually 1) which satisfy | fills numerical formula (VII) exists in the said wavelength range.

  The cross-sectional view schematically shown in FIG. 1 (b) is an example of the antireflection film of the present invention. The antireflection film 1 comprises a transparent support 2, each functional layer (hard coat layer 3, medium refractive index). Layer 7, high refractive index layer 8), low refractive index layer (outermost layer) 5. The transparent support 2, the medium refractive index layer 7, the high refractive index layer 8, and the low refractive index layer 5 have refractive indexes that satisfy the following relationship.

  Refractive index of high refractive index layer> refractive index of medium refractive index layer> refractive index of transparent support> refractive index of low refractive index layer

  In the layer structure as shown in FIG. 1B, as described in JP-A-59-50401, the medium refractive index layer is represented by the following mathematical formula (I), and the high refractive index layer is represented by the following mathematical formula (II). It is preferable that the low refractive index layer satisfies the following formula (III) in that an antireflection film having more excellent antireflection performance can be produced.

Formula (I)
(Hλ / 4) × 0.7 <n ₁ d ₁ <(hλ / 4) × 1.3

In the formula (I), h is a positive integer (generally 1, 2 or 3), n ₁ is the refractive index of the medium refractive index layer, and d ₁ is the layer thickness (nm) of the medium refractive index layer. It is. λ is the wavelength (nm) of visible light, and is a value in the range of 380 to 680 nm.

Formula (II)
(Iλ / 4) × 0.7 <n ₂ d ₂ <(iλ / 4) × 1.3

In formula (II), i is a positive integer (generally 1, 2 or 3), n ₂ is the refractive index of the high refractive index layer, and d ₂ is the layer thickness (nm) of the high refractive index layer. It is. λ is the wavelength (nm) of visible light, and is a value in the range of 380 to 680 nm.

Formula (III)
(Jλ / 4) × 0.7 <n ₃ d ₃ <(jλ / 4) × 1.3

In formula (III), j is a positive odd number (generally 1), n ₃ is the refractive index of the low refractive index layer, and d ₃ is the layer thickness (nm) of the low refractive index layer. λ is the wavelength (nm) of visible light, and is a value in the range of 380 to 680 nm.

  In the layer configuration as shown in FIG. 1B, the middle refractive index layer satisfies the following formula (IV), the high refractive index layer satisfies the following formula (V), and the low refractive index layer satisfies the following formula (VI). Is particularly preferred. Here, λ is 500 nm, h is 1, i is 2, and j is 1.

Formula (IV)
(Hλ / 4) × 0.80 <n ₁ d ₁ <(hλ / 4) × 1.00
Formula (V)
(Iλ / 4) × 0.75 <n ₂ d ₂ <(iλ / 4) × 0.95
Formula (VI)
(Jλ / 4) × 0.95 <n ₃ d ₃ <(jλ / 4) × 1.05

  The high refractive index, medium refractive index, and low refractive index described here refer to the relative refractive index between layers. Moreover, in FIG.1 (b), the high refractive index layer is used as a light interference layer, and the antireflection film which has the very outstanding antireflection performance can be produced.

  First, the optical functional film of the present invention, particularly the optical functional layer in the antireflection film will be described. Examples of the optical functional layer in the present invention include a low refractive index layer, a high refractive index layer, and a light diffusion layer.

  The optical functional layer in the antireflection film of the present invention is a coating composition for forming an optical functional layer, in particular, in order to ensure surface uniformity without coating unevenness, drying unevenness, point defects, etc. by high-speed coating. Contained in the product. This viscosity modifier is preferable because it has an effect of improving surface defects such as coating unevenness, drying unevenness, and point defects of the antireflection film.

  However, when the film thickness of the dry film is thin as in the low refractive index layer, the solid content concentration in the coating composition is preferably 1 to 20% by mass, and more preferably 1 to 15% by mass. Desirably, 1 to 10% by mass or less is further desirable, and 1 to 7% by mass or less is particularly desirable. If the solid content concentration is too high, the viscosity is low and the wet film thickness at the time of coating is low, and the applicability is deteriorated. If the solid content concentration is too low, the wet film thickness at the time of coating is high and drying unevenness occurs. Neither is preferred.

  As viscosity modifiers, polymethylmethacrylate, polyethylmethacrylate, polybutylmethacrylate, cellulose-based high molecular weight polymers, inorganic fine particles typified by silica, and inorganics that thicken by strengthening the interaction between inorganic fine particles As long as it has a property of thickening in an organic solvent, such as a surface treatment agent for fine particles, it can be used without particular limitation as long as the performance of the coating film is not deteriorated.

  The structure of the high molecular weight polymer that can be used in the present invention is not limited. Polyester, polyamide, polyimides obtained by polycondensation reaction, polymers obtained by addition polymerization reaction of ethylenically unsaturated monomers, and polymers obtained by polyaddition reaction, addition condensation reaction, ring-opening polymerization may be used. I can do it.

  In the case of using a high molecular weight polymer, in order to increase the viscosity with a small addition amount, a larger molecular weight is desirable, a mass average molecular weight is preferably 100,000 or more, more preferably 500,000 or more, and particularly preferably 1,000,000 or more. The mass average molecular weight values described in the present invention were measured using a TPCgel GMHxL, TSKgel G4000HxL, and TSKgel G2000HxL columns (both manufactured by Tosoh Corporation) using a tetrahydrofuran (THF) as a solvent. , Molecular weight expressed in terms of polystyrene by differential refractometer detection. In the present invention, the polymer having a mass average molecular weight of 100,000 or more means a polymer having a mass average molecular weight of 100,000 or more as a result of measurement by the measurement method.

  When such a high molecular weight polymer is used, the compatibility with the resin component contained in the coating composition needs to be good. In particular, when a high molecular weight polymer is used as the resin component of the low refractive index layer, the polymer of the high molecular weight polymer and the resin composition for the low refractive index layer may cause phase separation during the drying and curing process. It is necessary to take measures such as using a highly compatible viscosity modifier or reducing the molecular weight of the resin composition for the low refractive index layer.

  In order to solve the above phase separation problem, it is desirable to use inorganic fine particles having a thickening effect in a dispersed state in an organic solvent as a viscosity modifier. The average particle size of the inorganic fine particles needs to be 200 nm or less from the viewpoint of suppressing the haze of the coating film, preferably 150 nm or less, more preferably 120 nm or less, and particularly preferably 100 nm or less. The average particle diameter here is a particle diameter when dispersed in a solvent used in the coating composition to be used, and shows a value measured with a Coulter counter regardless of the shape of the particles.

  As the kind of inorganic fine particles, it is preferable to use inorganic fine particles having a low refractive index when used in a low refractive index layer, and inorganic fine particles having a high refractive index when used in a high refractive index layer. As the inorganic fine particles having a low refractive index, inorganic fine particles mainly composed of silica and magnesium fluoride are preferable, and inorganic fine particles mainly composed of silica are particularly preferable. On the other hand, the inorganic fine particles of the high refractive index layer are preferably oxide fine particles containing a metal such as Al, Zr, Ti, In, and Sn.

  In consideration of applicability when the viscosity modifier is added, it is particularly preferable to use a viscosity modifier having thixotropic properties. Thixotropic imparting agent shows good applicability with low viscosity at the time of high shearing force when applying the coating composition in a thin film on the base, and becomes high viscosity at subsequent low shear, good applicability and drying Satisfy both unevenness suppression. It is also effective against fluctuations in the thickness of the coating film due to disturbances such as apparatus vibration during application.

  Examples of the thixotropic agent include high molecular weight polymers such as ethyl cellulose and polyacrylic acid, inorganic fine particles such as silica and alumina (manufactured by Nippon Aerosil, various hydrophilic AEROSIL and hydrophobic Aerosil), inorganic layered compounds (mica, kaolinite, talc, Smectite, vermiculite) and the like, and so long as they do not affect the properties of each layer, there is no particular limitation. From the standpoint of thixotropic expression, dispersibility, etc., inorganic layered compounds are preferred. Smectite is desirable from the viewpoint of haze reduction by diameter and thixotropy, and synthetic smectite is desirable from the viewpoint of no coloration. Examples of the synthetic smectite include, but are not particularly limited to, an example in which Lucentite manufactured by Coop Chemical is preferably used.

  In order to use an inorganic layered compound in an organic solvent, it is necessary to improve the dispersibility in the organic solvent by performing an organic treatment. Inorganic layered compounds have exchangeable cations between crystal layers, and ion exchange with a cationic quaternary ammonium salt creates a complex of smectite and organic matter, making it easier to swell in organic solvents and improving dispersibility. To do.

  Although there is no limitation in particular about the quaternary ammonium salt used for an organic treatment, 0-3 are preferable, 0-2 are preferable, and 0-1 are especially preferable shown by General formula (1). When n is large, the dispersibility deteriorates, which is not preferable. Regarding Ra, all groups may have the same structure or different structures. m is 2 or more, and at least one group in Ra is particularly preferably 4 or more, more preferably 8 or more, and particularly preferably 8 to 30. The larger m is, the better the dispersibility, but it is not preferred, if it is too large, the ratio of the organic matter to the inorganic layered compound becomes too large.

It is also preferable from the viewpoint of thixotropy that Ra has a structure in which interaction between molecules is large. Examples of the structure that increases the interaction between molecules include —OH, —CH ₂ CH ₂ O—, —CHO (CH) ₃ —, and the like. Examples of the quaternary ammonium salt used in the organic treatment include dimethyldioctadecylammonium bromide, trimethyloctadecylammonium chloride, benzyltrimethylammonium chloride, dimethylbenzyloctadecylammonium bromide, trioctylmethylammonium chloride, polyoxypropylenetrimethylammonium chloride, di ( Polyoxypropylene) dimethylammonium chloride, di (polyoxyethylene) dodecylmethylammonium chloride, tri (polyoxypropylene) methylammonium chloride, tri (polyoxypropylene) methylammonium bromide and the like.

  The viscosity of the coating composition used in the present invention is preferably 5 mPa · s or less, particularly preferably 3.5 mPa · s or less, in the state where no viscosity modifier is added, from the viewpoint of the solid content concentration and the solvent composition. The following are particularly preferably used.

From the standpoint of viscosity increase or thixotropy of the viscosity modifier, it is desirable that the viscosity be increased to 1.3 times or more before addition by adding an amount within 5% by mass with respect to the total amount of the coating solution. . More preferably, it is added 2 times or more, particularly preferably 4 times or more, and most preferably 6 times or more. The viscosity here indicates the viscosity specified by the vibration viscometer. The addition amount of the viscosity modifier needs to be 5% by mass or less, preferably 3% by mass or less, more preferably 1% by mass or less, and more preferably 0.5% by mass or less with respect to the total amount of the coating solution. It is particularly preferred that
The total solid content needs to be 30% by mass or less, preferably 20% by mass or less, more preferably 10% by mass or less, and particularly preferably 5% by mass or less. Although there is no restriction | limiting in particular in a minimum, From a viewpoint of the thickening effect, 1 mass% or more is preferable and 3 mass% or more is especially desirable.

  The thixotropy may be difficult to measure when the concentration of the viscosity modifier is low. In the present invention, the viscosity of the coating composition with respect to the viscosity at a shear rate of 1000 (1 / s) when the addition amount of the viscosity modifier is 1% by mass is used. The viscosity ratio at a shear rate of 0.1 (1 / s) is defined. The viscosity ratio is preferably 10 or more, more preferably 50 or more, and particularly preferably 100 or more.

  If the performance of the coating film is changed by adding a viscosity modifier, it does not have desirable properties as an antireflection film, which is a problem. Particularly for the low refractive index layer, the influence on important properties such as scratch resistance, refractive index, and antifouling properties is important. Naturally, it is necessary that the scratch resistance does not deteriorate significantly due to the addition of the viscosity modifier, but the change in the refractive index needs to be 0.1 or less, preferably 0.05 or less. 0.02 or less is more preferable, and 0.01 or less is particularly preferable.

  The antifouling property is defined as a change in the contact angle of water on the coating surface as an index. In general, the contact angle of water is preferably 90 degrees or more, more preferably 95 degrees or more, and particularly preferably 100 degrees or more. Due to the addition of the viscosity modifier, the decrease in water contact angle is preferably 5 degrees or less, more preferably 2 degrees or less, and particularly preferably 1 degree or less.

  Solvents used in the coating solution for forming functional layers (antiglare hard coat layer, light diffusion layer, high refractive index layer, hard coat layer, etc.) and low refractive index layer) in the antireflection film of the present invention are as follows: explain.

  Examples of the coating solvent include hexane (boiling point: 68.7 ° C .; hereinafter, “° C.” is omitted), heptane (98.4), cyclohexane (80.7), benzene (80 .1) hydrocarbons, dichloromethane (39.8), chloroform (61.2), carbon tetrachloride (76.8), 1,2-dichloroethane (83.5), trichloroethylene (87.2), etc. Halogenated hydrocarbons, diethyl ether (34.6), diisopropyl ether (68.5), dipropyl ether (90.5), ethers such as tetrahydrofuran (66), ethyl formate (54.2), acetic acid Esters such as methyl (57.8), ethyl acetate (77.1), isopropyl acetate (89), acetone (56.1), 2-tanone (= methyl ethyl) Ketones, ketones such as 79.6), alcohols such as methanol (64.5), ethanol (78.3), 2-propanol (82.4), 1-propanol (97.2), acetonitrile (81 .6), cyano compounds such as propionitrile (97.4), carbon disulfide (46.2), and the like.

Examples of the solvent having a boiling point exceeding 100 ° C. include octane (125.7), toluene (110.6), xylene (138), tetrachloroethylene (121.2), chlorobenzene (131.7), and dioxane (101.3). ), Dibutyl ether (142.4), isobutyl acetate (118), cyclohexanone (155.7), 2-methyl-4-pentanone (same as MIBK, 115.9), 1-pentanol (117.7), N, N-methylformamide (153), N, N-methylacetamide (166), dimethyl sulfoxide (189) and the like. Preferred solvents are cyclohexanone and 2-methyl-4-pentanone.
The solvent is preferably such that the main component of the solvent used in the coating solution has a boiling point of 115 ° C. or lower and a dielectric constant of 22 or lower. If the boiling point is too high, drying tends to be difficult, and if the dielectric constant is too high, problems such as difficulty in dissolving the polymer tend to occur.
As a kind of solvent, ketones, aromatic hydrocarbons, and esters are preferable, and ketones are particularly preferable. Of the ketones, methyl ethyl ketone is particularly preferred.
When a ketone solvent is used, either a single solvent or a mixture may be used. When mixing, the content of the ketone solvent is preferably 10% by mass or more of the total solvent contained in the coating composition. Preferably it is 30 mass% or more, More preferably, it is 60 mass% or more.

In the antireflection film of the present invention, a functional layer and a low refractive index layer component are diluted with a solvent having the above-mentioned composition to prepare a coating solution for these layers. The concentration of the coating solution is preferably adjusted as appropriate in consideration of the viscosity of the coating solution and the specific gravity of the layer material, but is preferably 0.1 to 80% by mass, and more preferably 1 to 60% by mass.
Moreover, the solvent of each functional layer may be the same composition, and may differ.

Below, each functional layer of this invention is demonstrated.
[Anti-glare hard coat layer]
The antiglare hard coat layer according to the present invention will be described below.
The antiglare hard coat layer is formed of a binder for imparting hard coat properties and mat particles for imparting antiglare properties. An inorganic filler for increasing the refractive index, preventing crosslinking shrinkage, and increasing the strength can also be used by dispersing in a binder.
The binder is preferably a polymer having a saturated hydrocarbon chain or a polyether chain as the main chain, and more preferably a polymer having a saturated hydrocarbon chain as the main chain. The binder polymer preferably has a crosslinked structure.
As the binder polymer having a saturated hydrocarbon chain as a main chain, a polymer of an ethylenically unsaturated monomer (binder precursor) is preferable. As the binder polymer having a saturated hydrocarbon chain as the main chain and having a crosslinked structure, a (co) polymer of monomers having two or more ethylenically unsaturated groups is preferable.
In order to obtain a high refractive index, the monomer structure preferably contains an aromatic ring or at least one atom selected from a halogen atom other than fluorine, a sulfur atom, a phosphorus atom, and a nitrogen atom.

  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-chlorohexane tetramethacrylate, polyurethane polyacrylate, polyester poly Acrylate), vinylbenzene and derivatives thereof (eg, 1,4-vinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1,4-vinylcyclohexanone), 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”, “(meth) acryloyl”, and “(meth) acrylic acid” are “acrylate or methacrylate”, “acryloyl or methacryloyl”, “acrylic acid or methacrylic acid”, respectively. ".

  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.

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.
Accordingly, a coating liquid containing a monomer having an ethylenically unsaturated group, a photo radical initiator or a thermal radical initiator, mat particles, and an inorganic filler is prepared, and the coating liquid is applied on a transparent support and then ionizing radiation or heat is applied. It can be cured by a polymerization reaction to form an antireflection film.

As radical photopolymerization initiators, acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-alkyldione compounds, disulfide compounds , Fluoroamine compounds and aromatic sulfoniums. Examples of acetophenones include 2,2-ethoxyacetophenone, p-methylacetophenone, 1-hydroxydimethylphenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-morpholinopropiophenone and 2- Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone is included. Examples of benzoins include benzoin benzene sulfonate, benzoin toluene sulfonate, benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether. Examples of the benzophenones include benzophenone, 2,4-chlorobenzophenone, 4,4-dichlorobenzophenone and p-chlorobenzophenone. Examples of phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide.
Various examples are described in the latest UV curing technology (P.159, issuer; Kazuhiro Takasato, publisher; Technical Information Association, Inc., published in 1991), and are useful for the present invention.
Preferable examples of commercially available photocleavable photoradical polymerization initiators include Irgacure (651, 184, 907) manufactured by Ciba Specialty Chemicals.
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.

As the thermal radical initiator, organic or inorganic peroxides, organic azo, diazo compounds, and the like can be used.
Specifically, benzoyl peroxide, halogen benzoyl peroxide, lauroyl peroxide, acetyl peroxide, dibutyl peroxide, cumene hydroperoxide, butyl hydroperoxide as organic peroxides, hydrogen peroxide, peroxides as inorganic peroxides. Diazo compounds such as ammonium sulfate, potassium persulfate and the like, 2,2′-azobis (isobutyronitrile), 2,2′-azobis (propionitrile), 1,1′-azobis (cyclohexanecarbonitrile), etc. And diazoaminobenzene, p-nitrobenzenediazonium and the like.

The polymer having a polyether as the main chain is preferably a ring-opening polymer of a polyfunctional epoxy compound. 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.
Accordingly, a coating liquid containing a polyfunctional epoxy compound, a photoacid generator or a thermal acid generator, matte particles and an inorganic filler is prepared, and the coating liquid is applied onto a transparent support and then subjected to a polymerization reaction by ionizing radiation or heat. It can be cured to form an antireflective film.

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 anhydrides, cyanoacrylate derivatives, melamine, etherified methylol, esters and urethanes, and metal alkoxides such as tetramethoxysilane can also be used as monomers for introducing a crosslinked structure. Moreover, you may use the functional group which shows crosslinkability as a result of a decomposition reaction like the blocked isocyanate group. 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.

  The binder of the antiglare hard coat layer is added in an amount of 20 to 95% by mass based on the solid content of the coating composition of the layer.

For the purpose of imparting antiglare properties, the antiglare hard coat layer is larger than filler particles and has an average particle size of 0.5 to 10 μm, preferably 1 to 5 μm, more preferably 1.5 to 4 μm, For example, inorganic compound particles or resin particles are contained.
Specific examples of the mat particles include particles of inorganic compounds such as silica particles and TiO ₂ particles, acrylic particles, crosslinked acrylic particles, polystyrene particles, crosslinked styrene particles, melamine resin particles, benzoguanamine resin particles, or these resin particles. The resin particle containing 2 or more types of components of these is preferably mentioned. Of these, particles mainly composed of crosslinked styrene, crosslinked acryl and silica are preferred.
The shape of the mat particles can be either a true sphere or an indefinite shape.

  Two or more kinds of mat particles having different particle diameters may be used in combination. It is possible to impart anti-glare properties with mat particles having a larger particle size and to impart other optical characteristics with mat particles having a smaller particle size.

  When an antireflection film is attached to a high-definition display of 133 ppi or higher, 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. Further, by adjusting the refractive index and the particle diameter with one kind of particles, it is possible to achieve both antiglare property and improvement in glare.

  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 particles having a particle size of 20% or more than the average particle size are defined as coarse particles, the proportion of coarse particles is preferably 1% or less of the total number of particles, more preferably 0.1%. 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 anti-glare hard coat layer so that the amount of the mat particles in the formed anti-glare hard coat layer is preferably 10 to 2000 mg / m ² , more preferably 100 to 1400 mg / m ^2. Is done.
The particle size distribution of the mat particles is measured by a Coulter counter method, and the measured distribution is converted into a particle number distribution.

In order to increase the refractive index of the antiglare hard coat layer, in addition to the above mat particles, at least one metal selected from titanium, zirconium, aluminum, indium, zinc, tin, and antimony is used. An inorganic filler made of an 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 can also be contained.
Conversely, in order to increase the difference in refractive index from the mat particles, an anti-glare hard coat layer using high refractive index mat particles uses silicon oxide to keep the refractive index of the layer low. Is also preferable. The preferred particle size is the same as that of the aforementioned inorganic filler.
Specific examples of the inorganic filler for use in the antiglare hard coat _{layer, TiO 2, ZrO 2, Al} 2 O 3, In 2 O 3, ZnO, SnO 2, Sb 2 O 3, ITO and SiO ₂ or the like can be mentioned It is done. TiO ₂ and ZrO ₂ are particularly preferable in terms of increasing the refractive index. The surface of the inorganic filler is preferably subjected to a silane coupling treatment or a titanium coupling treatment, and a surface treatment agent having a functional group capable of reacting with a binder species on the filler surface is preferably used.
The amount of these inorganic fillers added is preferably 10 to 90% of the total mass of the antiglare hard coat layer, more preferably 20 to 80%, and particularly preferably 30 to 75%.
In addition, since such a filler has a particle size sufficiently smaller than the wavelength of light, scattering does not occur, 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 antiglare 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 film thickness of the antiglare hard coat layer is preferably 1 to 10 μm, and more preferably 1.2 to 8 μm.

[Light diffusion layer]
The purpose of the light diffusing layer in the optical functional film of the present invention is to enlarge the viewing angle (particularly the downward viewing angle) of the liquid crystal display device and to reduce contrast, gradation or black-and-white reversal, even if the viewing angle in the viewing direction changes. It is to suppress the hue change.
The present inventors have confirmed that the intensity distribution of scattered light measured with a goniophotometer correlates with the viewing angle improvement effect. That is, as the light emitted from the backlight is diffused by the effect of internal scattering of the translucent fine particles contained in the light diffusion film installed on the surface of the polarizing plate on the viewing side, the viewing angle characteristics are improved. However, if it is diffused too much, backscattering will increase and the front luminance will decrease, or the scattering will be too great and the image clarity will deteriorate. Therefore, it is necessary to control the scattered light intensity distribution within a certain range. Therefore, as a result of intensive studies, in order to achieve the desired visual characteristics, the scattered light intensity at 30 °, which correlates particularly with the visual angle improvement effect, is 0.01 with respect to the light intensity at the output angle 0 ° of the scattered light profile. % To 0.2% is preferable, 0.02% to 0.15% is more preferable, and 0.03% to 0.1% is particularly preferable.
The scattered light profile can be measured using the automatic variable angle photometer GP-5 manufactured by Murakami Color Research Laboratory Co., Ltd. for the created light scattering film.

  The light diffusing layer of the present invention is formed from a binder, an inorganic filler, and translucent fine particles, and the binder and the inorganic filler can be the same as those described above for the antiglare hard coat layer. The same is used.

  The binder of the light diffusing layer is added in an amount of 5 to 80% by mass based on the solid content of the coating composition of the layer.

  The light diffusion layer may be provided as a layer separate from the antiglare hard coat layer, but it is generally desirable that one layer has both functions.

[High refractive index layer]
In the antireflection film of the present invention, a high refractive index layer can be preferably used in order to impart better antireflection performance.

<Inorganic fine particles mainly composed of titanium dioxide>
The high refractive index layer of the present invention contains inorganic fine particles mainly composed of titanium dioxide containing at least one element selected from cobalt, aluminum, and zirconium. The main component means a component having the largest content (mass%) among the components constituting the particles.
The refractive index of the high refractive index layer of the present invention is a refractive index of 1.55 to 2.40, which is a so-called high refractive index layer or a medium refractive index layer. The layer may be collectively referred to as a high refractive index layer.
The inorganic fine particles mainly composed of titanium dioxide in the present invention preferably have a refractive index of 1.90 to 2.80, more preferably 2.10 to 2.80, and 2.20 to 2.80. 80 is most preferred.
The mass average diameter of primary particles of inorganic fine particles mainly composed of titanium dioxide is preferably 1 to 200 nm, more preferably 1 to 150 nm, still more preferably 1 to 100 nm, and particularly preferably 1 to 80 nm.

The particle diameter of the inorganic fine particles can be measured by a light scattering method or an electron micrograph. The specific surface area of the inorganic fine particles is preferably 10 to 400 m ² / g, more preferably from 20 to 200 m ² / g, and most preferably from 30 to 150 m ² / g.
The crystal structure of the inorganic fine particles containing titanium dioxide as the main component is preferably a rutile, rutile / anatase mixed crystal, anatase or amorphous structure, particularly preferably a rutile structure. The main component means a component having the largest content (mass%) among the components constituting the particles.

By incorporating at least one element selected from Co, Al and Zr into inorganic fine particles mainly composed of titanium dioxide, the photocatalytic activity of titanium dioxide can be suppressed, and the weather resistance of the high refractive index layer of the present invention. Can be improved.
In particular, the preferred element is Co. It is also preferable to use two or more types in combination.
The content of Co, Al or Zr with respect to Ti is preferably 0.05 to 30% by mass, more preferably 0.1 to 10% by mass, and still more preferably 0.2 to 7% by mass with respect to Ti. %, Particularly preferably 0.3 to 5% by mass, most preferably 0.5 to 3% by mass.
Co, Al, and Zr can be present in at least one of the inside and the surface of the inorganic fine particles mainly composed of titanium dioxide, but are preferably present inside the inorganic fine particles mainly composed of titanium dioxide, Most preferably it is present both inside and on the surface.
There are various methods for causing Co, Al, and Zr to exist (for example, dope) in the inorganic fine particles mainly composed of titanium dioxide. For example, ion implantation (Vol.18, No.5, pp.262-268, 1998; Yasushi Aoki), JP-A-11-263620, JP-A-11-512336, European Patent Application Publication No. 0335773. And the method described in JP-A-5-330825.
Techniques for introducing Co, Al, and Zr in the process of forming inorganic fine particles containing titanium dioxide as a main component (for example, Japanese Patent Application Laid-Open No. 11-512336, European Patent Application Publication No. 0335773, Japanese Patent Application Laid-Open No. Hei 5- No. 330308) is particularly preferable.
Co, Al, and Zr are also preferably present as oxides.
The inorganic fine particles containing titanium dioxide as the main component can further contain other elements depending on the purpose. Other elements may be included as impurities. Examples of other elements include Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Mg, Si, P, and S.

The inorganic fine particles mainly composed of titanium dioxide used in the present invention may be surface-treated. The surface treatment is performed using an inorganic compound or an organic compound. Examples of inorganic compounds used for the surface treatment include inorganic compounds containing cobalt (CoO ₂ , Co ₂ O ₃ , Co ₃ O _4, etc.) and inorganic compounds containing aluminum (Al ₂ O ₃ , Al (OH) ₃ Etc.), inorganic compounds containing zirconium (ZrO ₂ , Zr (OH) ₄ etc.), inorganic compounds containing silicon (SiO ₂ etc.), inorganic compounds containing iron (Fe ₂ O ₃ etc.), etc. .
An inorganic compound containing cobalt, an inorganic compound containing aluminum, and an inorganic compound containing zirconium are particularly preferable, and an inorganic compound containing cobalt, Al (OH) _{3, and} Zr (OH) ₄ are most preferable.
Examples of organic compounds used for the surface treatment include polyols, alkanolamines, stearic acid, silane coupling agents, and titanate coupling agents. Of these, silane coupling agents are most preferred. In particular, the surface treatment is preferably performed with at least one of a silane coupling agent (organosilane compound) represented by the following general formula 5, a partial hydrolyzate thereof, and a condensate thereof. The silane coupling agent represented by the general formula 5 will be described in detail later.

Examples of titanate coupling agents include metal alkoxides such as tetraisopropoxytitanium such as tetramethoxytitanium and tetraethoxytitanium, and preneact (KR-TTS, KR-46B, KR-55, KR-41B, etc .; Ajinomoto Co., Inc.) Manufactured).
Examples of the organic compound used for the surface treatment include polyols, alkanolamines, and other organic compounds having an anionic group, and particularly preferable are organic compounds having a carboxyl group, a sulfonic acid group, or a phosphoric acid group. is there.
As the organic compound having a carboxyl group, stearic acid, lauric acid, oleic acid, linoleic acid, linolenic acid and the like can be preferably used.
The organic compound used for the surface treatment preferably further has a crosslinked or polymerizable functional group. Crosslinkable or polymerizable functional groups include ethylenically unsaturated groups (for example, (meth) acrylic groups, allyl groups, styryl groups, vinyloxy groups, etc.) that can undergo addition reactions and polymerization reactions with radical species, cationic polymerizable groups (Epoxy groups, oxatanyl groups, vinyloxy groups, etc.), polycondensation reactive groups (hydrolyzable silyl groups, etc., N-methylol groups) and the like can be mentioned, and groups having an ethylenically unsaturated group are preferred.

Two or more kinds of these surface treatments can be used in combination. It is particularly preferable to use an inorganic compound containing aluminum and an inorganic compound containing zirconium in combination.
The inorganic fine particles mainly composed of titanium dioxide of the present invention may have a core / shell structure by surface treatment as described in JP-A No. 2001-166104.

  The shape of the inorganic fine particles mainly composed of titanium dioxide contained in the high refractive index layer is preferably a rice grain shape, a spherical shape, a cubic shape, a spindle shape or an indefinite shape, and particularly preferably an indefinite shape or a spindle shape. is there.

<Dispersant>
A dispersant can be used to disperse the inorganic fine particles mainly composed of titanium dioxide used in the high refractive index layer of the present invention.
It is particularly preferable to use a dispersant having an anionic group for dispersing the inorganic fine particles mainly composed of titanium dioxide of the present invention.
As the anionic group, a group having an acidic proton such as a carboxyl group, a sulfonic acid group (and a sulfo group), a phosphoric acid group (and a phosphono group), or a sulfonamide group, or a salt thereof is effective. A sulfonic acid group, a phosphoric acid group and a salt thereof are preferable, and a carboxyl group and a phosphoric acid group are particularly preferable. The number of anionic groups contained in the dispersant per molecule may be one or more.
A plurality of anionic groups may be contained for the purpose of further improving the dispersibility of the inorganic fine particles. 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 preferably further contains a crosslinkable 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 (epoxy 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.
A preferred dispersant used for dispersion of inorganic fine particles mainly composed of titanium dioxide used in the high refractive index layer of the present invention has an anionic group and a crosslinkable or polymerizable functional group, and the crosslinkable or polymerizable functional group. In the side chain.
The weight average molecular weight (Mw) of the dispersant having an anionic group and a crosslinkable or polymerizable functional group and having the crosslinkable or polymerizable functional group in the side chain is not particularly limited, but is preferably 1000 or more. . The more preferable weight average molecular weight (Mw) of the dispersant is 2,000 to 1,000,000, more preferably 5,000 to 200,000, and particularly preferably 10,000 to 100,000.

  As the anionic group, a group having an acidic proton such as a carboxyl group, a sulfonic acid group (and a sulfo group), a phosphoric acid group (and a phosphono group), or a sulfonamide group, or a salt thereof is effective. A sulfonic acid group, a phosphoric acid group or a salt thereof is preferred, and a carboxyl group and a phosphoric acid group are particularly preferred. The average number of anionic groups contained in the dispersant per molecule 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 having an anionic group and a crosslinkable or polymerizable functional group and having the crosslinkable or polymerizable functional group in the side chain has the anionic group in the side chain or terminal.
Particularly preferred dispersants are those having an anionic group in the side chain. In the dispersant having an anionic group in the side chain, the composition of the anionic group-containing repeating unit is in the range of 10 ^{−4 to} 100 mol%, preferably 1 to 50 mol%, particularly preferably 5 in the total repeating units. ˜20 mol%.

  Examples of the cross-linkable or polymerizable functional group include ethylenically unsaturated groups (for example, (meth) acryl group, allyl group, styryl group, vinyloxy group, etc.) capable of addition reaction / polymerization reaction with radical species, cationic polymerizable group (epoxy) Groups, oxatanyl groups, vinyloxy groups, etc.), polycondensation reactive groups (hydrolyzable silyl groups, etc., N-methylol groups), and the like. Preferred are groups having an ethylenically unsaturated group.

  The average number of cross-linkable or polymerizable functional groups contained in the dispersant per molecule is preferably 2 or more, more preferably 5 or more, and particularly preferably 10 or more. Moreover, the crosslinking or polymerizable functional group contained in the dispersant may contain a plurality of types in one molecule.

In the preferred dispersant for use in the present invention, examples of the repeating unit having an ethylenically unsaturated group in the side chain include poly-1,2-butadiene and poly-1,2-isoprene structures or (meth) acrylic acid. An ester or amide repeating unit to which a specific residue (the R group of —COOR or —CONHR) is bonded can be used. Examples of the specific residue (R _{group), - (CH 2) n} -CR 21 = CR 22 R 23, - (CH 2 O) n-CH 2 CR 21 = CR 22 R 23, - (CH _{2 CH 2 O) n-CH} 2 CR 21 = CR 22 R 23, - (CH 2) n-NH-CO-O-CH 2 CR 21 = CR 22 R 23, - (CH 2) nO-CO- CR ²¹ = CR ²² R ²³ and — (CH ₂ CH ₂ O) ₂ —X (R ^{21 to} R ²³ are each a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, an alkoxy group, An aryloxy group, R ²¹ and R ²² or R ²³ may be bonded to each other to form a ring, n is an integer of 1 to 10, and X is a dicyclopentadienyl residue) Can be mentioned. Specific examples of R of the ester residue include —CH ₂ CH═CH ₂ (corresponding to an allyl (meth) acrylate polymer described in JP-A No. 64-17047), —CH ₂ CH ₂ O—CH ₂ CH _{= CH 2, -CH 2 CH 2} OCOCH = CH 2, -CH 2 CH 2 OCOC (CH 3) = CH 2, -CH 2 C (CH 3) = CH 2, -CH 2 CH = CH-C 6 H _{5, -CH 2 CH 2 OCOCH =} CH-C 6 H 5, -CH 2 CH 2 -NHCOO-CH 2 CH = CH 2 and -CH ₂ CH ₂ OX (X is a dicyclopentadienyl residue) is included It is. Specific examples of R of the amide residue include —CH ₂ CH═CH ₂ , —CH ₂ CH ₂ —Y (Y is a 1-cyclohexenyl residue) and —CH ₂ CH ₂ —OCO—CH═CH ₂ , _{-CH 2 CH 2 -OCO-C (} CH 3) = CH 2 are included.

  In the dispersant having an ethylenically unsaturated group, a free radical (a polymerization initiation radical or a growth radical of a polymerization process of a polymerizable compound) is added to the unsaturated bond group, and the polymer compound is directly or between molecules. Addition polymerization is carried out through the polymerization chain, and a crosslink is formed between the molecules to cure. Alternatively, atoms in the molecule (for example, hydrogen atoms on carbon atoms adjacent to the unsaturated bond group) are extracted by free radicals to form polymer radicals that are bonded together to form a bridge between the molecules. Harden.

The cross-linkable or polymerizable functional group-containing unit may constitute all repeating units other than the anionic group-containing repeating unit, preferably 5 to 50 mol% of all cross-linked or repeating units, particularly Preferably it is 5-30 mol%.
A preferable dispersant of the present invention may be a copolymer with a suitable monomer other than a monomer having a crosslinkable or polymerizable functional group or an anionic group. Although it does not specifically limit regarding a copolymerization component, It selects from various viewpoints, such as dispersion stability, compatibility with another monomer component, and the intensity | strength of a formed film. Preferable examples include methyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, cyclohexyl (meth) acrylate, styrene and the like.
The preferred dispersant form of the present invention is not particularly limited, but is preferably a block copolymer or a random copolymer, and particularly preferably a random copolymer from the viewpoint of cost and synthetic ease.

  Specific examples of the dispersant preferably used in the present invention are shown below, but the dispersant for the present invention is not limited thereto. Unless otherwise specified, it represents a random copolymer.

  The amount of the dispersant used relative to the inorganic fine particles is preferably in the range of 1 to 50% by mass, more preferably in the range of 5 to 30% by mass, and most preferably 5 to 20% by mass. Two or more dispersants may be used in combination.

<High refractive index layer and formation method thereof>
The inorganic fine particles mainly composed of titanium dioxide used for the high refractive index layer are used for forming the high refractive index layer in a dispersion state.
In the dispersion of the inorganic fine particles, it is dispersed in a dispersion medium in the presence of the dispersant.
As the dispersion medium, a liquid having a boiling point of 60 to 170 ° C. is preferably used. Examples of dispersion media include water, alcohol (eg, methanol, ethanol, isopropanol, butanol, benzyl alcohol), ketone (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), ester (eg, methyl acetate, ethyl acetate, Propyl acetate, butyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate), aliphatic hydrocarbons (eg, hexane, cyclohexane), halogenated hydrocarbons (eg, methylene chloride, chloroform, carbon tetrachloride), aromatic Hydrocarbon (eg, benzene, toluene, xylene), amide (eg, dimethylformamide, dimethylacetamide, n-methylpyrrolidone), ether (eg, diethyl ether, dioxane, tetrahydrofuran), ether alcohol (eg, 1-methyl) Carboxymethyl-2-propanol) are included. Toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and butanol are preferred.
Particularly preferred dispersion media are methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and toluene.

The inorganic fine particles are dispersed using a disperser. 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.
The inorganic fine particles are preferably made as fine as possible in the dispersion medium, and the mass average diameter is 1 to 200 nm. Preferably it is 5-150 nm, More preferably, it is 10-100 nm, Most preferably, it is 10-80 nm.
By refining the inorganic fine particles to 200 nm or less, a high refractive index layer that does not impair the transparency can be formed.

  The high-refractive index layer used in the present invention is preferably added to the dispersion liquid in which the inorganic fine particles are dispersed in the dispersion medium as described above, preferably a binder precursor necessary for matrix formation (of the antiglare hard coat layer described above). The same as the binder precursor), a photopolymerization initiator, etc. are added to form a coating composition for forming a high refractive index layer, and the coating composition for forming a high refractive index layer is coated on a transparent support, and ionized. It is preferably formed by curing by a crosslinking reaction or a polymerization reaction of a radiation curable compound (for example, a polyfunctional monomer or a polyfunctional oligomer).

Further, it is preferable to cause the binder of the high refractive index layer to undergo a crosslinking reaction or a polymerization reaction with the dispersant simultaneously with or after the application of the layer.
The binder of the high refractive index layer thus prepared is, for example, the above-mentioned preferred dispersant and an ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer cross-linked or polymerized, and the binder is anionic. The base is incorporated. Furthermore, the binder of the high refractive index layer has a function in which the anionic group maintains the dispersed state of the inorganic fine particles, and the cross-linked or polymerized structure imparts a film forming ability to the binder to contain the inorganic fine particles. Improves physical strength, chemical resistance, and weather resistance.

It is preferable to use a photopolymerization initiator for the polymerization reaction of the photopolymerizable polyfunctional monomer. As the photopolymerization initiator, a photoradical polymerization initiator and a photocationic polymerization initiator are preferable, and a photoradical polymerization initiator is particularly preferable.
As the radical photopolymerization initiator, the same antiglare hard coat layer as described above can be used.

In the high refractive index layer, the binder preferably further has a silanol group. When the binder further has a silanol group, the physical strength, chemical resistance, and weather resistance of the high refractive index layer are further improved.
The silanol group is, for example, a silanol compound represented by the following general formula 5 having a crosslinked or polymerizable functional group, particularly a silane coupling agent, a partial hydrolyzate thereof, or a condensate thereof for forming the above high refractive index layer The coating composition is coated on a transparent support, and the above-mentioned dispersant, polyfunctional monomer or polyfunctional oligomer, a silane coupling agent represented by the general formula 5 described later, and its partial hydrolysis The decomposition product or the condensate thereof can be introduced into the binder by crosslinking reaction or polymerization reaction.

In the high refractive index layer, the binder preferably has an amino group or a quaternary ammonium group.
For the binder of the high refractive index layer having an amino group or quaternary ammonium group, for example, a monomer having a crosslinkable or polymerizable functional group and an amino group or quaternary ammonium group is added to the coating composition for forming the above high refractive index layer. And it can form by apply | coating a coating composition on a transparent support body, carrying out a crosslinking reaction or a polymerization reaction with said dispersing agent, a polyfunctional monomer, or a polyfunctional oligomer.

  A monomer having an amino group or a quaternary ammonium group functions as a dispersion aid for inorganic fine particles in the coating composition. Furthermore, after coating, a dispersant, a polyfunctional monomer or a polyfunctional oligomer is crosslinked or polymerized to form a binder, thereby maintaining good dispersibility of the inorganic fine particles in the high refractive index layer, physical strength, resistance A high refractive index layer excellent in chemical properties and weather resistance can be produced.

Preferred monomers having an amino group or quaternary ammonium group include N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, hydroxypropyltrimethylammonium chloride (meth) acrylate, dimethyl And allyl ammonium chloride.
It is preferable that the usage-amount with respect to the dispersing agent of the monomer which has an amino group or a quaternary ammonium group is 1-40 mass%, More preferably, it is 3-30 mass%, Most preferably, it is 3-20 mass%. If the binder is formed by crosslinking or polymerization reaction simultaneously with or after the application of the high refractive index layer, these monomers can be effectively functioned before the application of the high refractive index layer.

  The crosslinked or polymerized binder has a structure in which the main chain of the polymer is crosslinked or polymerized. Examples of the polymer main chain include polyolefin (saturated hydrocarbon), polyether, polyurea, polyurethane, polyester, polyamine, polyamide and melamine resin. A polyolefin main chain, a polyether main chain and a polyurea main chain are preferable, a polyolefin main chain and a polyether main chain are more preferable, and a polyolefin main chain is most preferable.

  The polyolefin main chain is composed of a saturated hydrocarbon. The polyolefin main chain is obtained, for example, by an addition polymerization reaction of an unsaturated polymerizable group. The polyether main chain has repeating units bonded by an ether bond (—O—). The polyether main chain is obtained, for example, by a ring-opening polymerization reaction of an epoxy group. In the polyurea main chain, repeating units are bonded by a urea bond (—NH—CO—NH—). The polyurea main chain is obtained, for example, by a condensation polymerization reaction between an isocyanate group and an amino group. The polyurethane main chain has repeating units bonded by urethane bonds (—NH—CO—O—). The polyurethane main chain is obtained, for example, by a polycondensation reaction between an isocyanate group and a hydroxyl group (including an N-methylol group). The polyester main chain has repeating units bonded by an ester bond (—CO—O—). The polyester main chain is obtained, for example, by a polycondensation reaction between a carboxyl group (including an acid halide group) and a hydroxyl group (including an N-methylol group). In the polyamine main chain, repeating units are bonded by an imino bond (—NH—). The polyamine main chain is obtained, for example, by a ring-opening polymerization reaction of an ethyleneimine group. The polyamide main chain has repeating units bonded by an amide bond (—NH—CO—). The polyamide main chain is obtained, for example, by a reaction between an isocyanate group and a carboxyl group (including an acid halide group). The melamine resin main chain is obtained, for example, by a polycondensation reaction between a triazine group (eg, melamine) and an aldehyde (eg, formaldehyde). In the melamine resin, the main chain itself has a crosslinked or polymerized structure.

The anionic group is preferably bonded to the main chain as a side chain of the binder via a linking group.
The linking group that binds the anionic group and the main chain of the binder is preferably a divalent group selected from —CO—, —O—, an alkylene group, an arylene group, and combinations thereof. The crosslinked or polymerized structure chemically bonds (preferably covalently bonds) two or more main chains. In the crosslinked or polymerized structure, it is preferable to covalently bond three or more main chains. The crosslinked or polymerized structure is preferably composed of a divalent or higher valent group selected from —CO—, —O—, —S—, a nitrogen atom, a phosphorus atom, an aliphatic residue, an aromatic residue, and combinations thereof. .

  The binder is preferably a copolymer having a repeating unit having an anionic group and a repeating unit having a crosslinked or polymerized structure. The proportion of the repeating unit having an anionic group in the copolymer is preferably 2 to 96 mol%, more preferably 4 to 94 mol%, and most preferably 6 to 92 mol%. The repeating unit may have two or more anionic groups. The proportion of the repeating unit having a crosslinked or polymerized structure in the copolymer is preferably 4 to 98 mol%, more preferably 6 to 96 mol%, and most preferably 8 to 94 mol%.

The repeating unit of the binder may have both an anionic group and a crosslinked or polymerized structure. The binder may contain other repeating units (repeating units having neither an anionic group nor a crosslinked or polymerized structure).
Other repeating units are preferably repeating units having a silanol group, an amino group or a quaternary ammonium group.

  In the repeating unit having a silanol group, the silanol group is directly bonded to the main chain of the binder or is bonded to the main chain via a linking group. The silanol group is preferably bonded to the main chain as a side chain via a linking group. The linking group that connects the silanol group and the main chain of the binder is preferably a divalent group selected from —CO—, —O—, an alkylene group, an arylene group, and combinations thereof. When the binder contains a repeating unit having a silanol group, the ratio is preferably 2 to 98 mol%, more preferably 4 to 96 mol%, and most preferably 6 to 94 mol%.

  In the repeating unit having an amino group or a quaternary ammonium group, the amino group or quaternary ammonium group is directly bonded to the main chain of the binder or bonded to the main chain via a linking group. The amino group or quaternary ammonium group is preferably bonded to the main chain as a side chain via a linking group. The amino group or quaternary ammonium group is preferably a secondary amino group, a tertiary amino group or a quaternary ammonium group, more preferably a tertiary amino group or a quaternary ammonium group. The group bonded to the nitrogen atom of the secondary amino group, tertiary amino group or quaternary ammonium group is preferably an alkyl group, preferably an alkyl group having 1 to 12 carbon atoms, Is more preferably an alkyl group of 1 to 6. The counter ion of the quaternary ammonium group is preferably a halide ion. The linking group that connects the amino group or the quaternary ammonium group to the main chain of the binder is a divalent group selected from —CO—, —NH—, —O—, an alkylene group, an arylene group, and combinations thereof. Preferably there is. When the binder includes a repeating unit having an amino group or a quaternary ammonium group, the ratio is preferably 0.1 to 32 mol%, more preferably 0.5 to 30 mol%, and more preferably 1 to 28 mol. % Is most preferred.

In addition, even if the silanol group, amino group, and quaternary ammonium group are contained in a repeating unit having an anionic group or a repeating unit having a crosslinked or polymerized structure, the same effect can be obtained.
The binder that has been crosslinked or polymerized is preferably formed by coating a coating composition for forming a high refractive index layer on a transparent support, and by crosslinking or polymerization reaction simultaneously with or after coating.

  The binder of the high refractive index layer is added in an amount of 5 to 80% by mass based on the solid content of the coating composition of the layer.

The inorganic fine particles have a function of controlling the refractive index of the high refractive index layer and a function of suppressing curing shrinkage.
In the high refractive index layer, the inorganic fine particles are preferably dispersed as finely as possible, and the mass average diameter is 1 to 200 nm. The mass average diameter of the inorganic fine particles in the high refractive index layer is preferably 5 to 150 nm, more preferably 10 to 100 nm, and most preferably 10 to 80 nm.
By refining the inorganic fine particles to 200 nm or less, a high refractive index layer that does not impair the transparency can be formed.

The content of the inorganic fine particles in the high refractive index layer is preferably 10 to 90% by mass, more preferably 15 to 80% by mass, and particularly preferably 15 to 75% by mass with respect to the mass of the high refractive index layer. . Two or more inorganic fine particles may be used in combination in the high refractive index layer.
When the low refractive index layer is provided on the high refractive index layer, the refractive index of the high refractive index layer is preferably higher than the refractive index of the transparent support.
The high refractive index layer contains an ionizing radiation curable compound containing an aromatic ring, an ionizing radiation curable compound containing a halogenated element other than fluorine (for example, Br, I, Cl, etc.), and atoms such as S, N, P, etc. A binder obtained by a crosslinking or polymerization reaction such as an ionizing radiation curable compound can also be preferably used.
In order to construct an antireflection film by constructing a low refractive index layer on a high refractive index layer, the refractive index of the high refractive index layer is preferably 1.55 to 2.40, more preferably It is 1.60 to 2.20, more preferably 1.65 to 2.10, and most preferably 1.80 to 2.00.

For the high refractive index layer, in addition to the above components (inorganic fine particles, polymerization initiator, photosensitizer, etc.), resin, surfactant, antistatic agent, coupling agent, viscosity modifier, anti-coloring agent, coloring Agents (pigments, dyes), antifoaming agents, leveling agents, flame retardants, ultraviolet absorbers, infrared absorbers, adhesion promoters, polymerization inhibitors, antioxidants, surface modifiers, conductive metal fine particles, etc. It can also be added.
The film thickness of the high refractive index layer can be appropriately designed depending on the application. When using a high refractive index layer as an optical interference layer described later, the thickness is preferably 30 to 200 nm, more preferably 50 to 170 nm, and particularly preferably 60 to 150 nm.

In the present invention, the crosslinking reaction or polymerization reaction of the ionizing radiation curable compound is preferably performed in an atmosphere having an oxygen concentration of 10% by volume or less. This is not limited to the formation of the high refractive index layer, but is common to the antiglare hard coat layer and the light diffusing layer.
By forming the high refractive index layer in an atmosphere having an oxygen concentration of 10% by volume or less, the physical strength, chemical resistance, and weather resistance of the high refractive index layer, and further, the high refractive index layer and the high refractive index layer are adjacent to each other. Adhesion with the layer can be improved.
Preferably, it is formed by a crosslinking reaction or polymerization reaction of an ionizing radiation curable compound in an atmosphere having an oxygen concentration of 6% by volume or less, more preferably an oxygen concentration of 4% by volume or less, particularly preferably an oxygen concentration of 2 Volume% or less, most preferably 1 volume% or less.
As a method of reducing the oxygen concentration to 10% by volume or less, it is preferable to replace the atmosphere (nitrogen concentration of about 79% by volume, oxygen concentration of about 21% by volume) with another gas, particularly preferably replacement with nitrogen (nitrogen purge). It is to be.

The strength of the high refractive index layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher in a pencil hardness test according to JIS K5400.
Further, in the Taber test according to JIS K5400, the smaller the wear amount of the test piece before and after the test, the better.
The haze of the high refractive index layer is preferably as low as possible when it does not contain particles that impart an antiglare function. It is preferably 5% or less, more preferably 3% or less, and particularly preferably 1% or less.
The high refractive index layer is preferably constructed directly on the transparent support or via another layer.
The medium refractive index layer can be constructed in the same manner as the high refractive index layer by adjusting the kind and addition amount of the binder and inorganic fine particles described in the high refractive index layer.

[Hard coat layer]
The hard coat layer may be a hard coat layer that also serves as an antiglare layer or a light diffusing layer, but for the purpose of achieving good optical performance and physical performance by functional separation, an antireflection film is used as the hard coat layer A so-called smooth hard coat layer that is not anti-glare is also preferably used in order to impart physical strength. In this case, it is provided on the surface of the transparent support. In particular, the transparent support and the antiglare hard coat layer, the transparent support and the light diffusion layer, and the transparent support and the high refractive index layer are preferably provided.
The hard coat layer is preferably formed by a crosslinking reaction or a polymerization reaction of an ionizing radiation curable compound. For example, it may be formed by applying a coating composition containing an ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer on a transparent support and subjecting the polyfunctional monomer or polyfunctional oligomer to a crosslinking reaction or a polymerization reaction. it can.
The functional group of the ionizing radiation-curable polyfunctional monomer or polyfunctional oligomer is preferably a light, electron beam, or radiation polymerizable group, and among them, a photopolymerizable functional group is preferable.
Examples of the photopolymerizable functional group include unsaturated polymerizable functional groups such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group. Among them, a (meth) acryloyl group is preferable. Specific examples of the ionizing radiation-curable polyfunctional monomer and polyfunctional oligomer are the same as those described for the antiglare hard coat layer.

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

  The binder of the hard coat layer is added in an amount of 30 to 95% by mass based on the solid content of the coating composition of the layer.

The hard coat layer preferably contains inorganic fine particles having an average primary particle size of 200 nm or less. The average particle diameter here is a mass average diameter. By setting the average particle size of the primary particles to 200 nm or less, a hard coat layer that does not impair transparency can be formed.
The inorganic fine particles have functions of increasing the hardness of the hard coat layer and suppressing curing shrinkage of the coating layer. It is also added for the purpose of controlling the refractive index of the hard coat layer.
As inorganic fine particles, in addition to the inorganic fine particles exemplified in the high refractive index layer, silicon dioxide, aluminum oxide, calcium carbonate, barium sulfate, talc, kaolin, calcium sulfate, titanium dioxide, zirconium oxide, tin oxide, ITO, zinc oxide, etc. Fine particles. Silicon dioxide, titanium dioxide, zirconium oxide, aluminum oxide, tin oxide, ITO, and zinc oxide are preferable.

The preferable average particle diameter of the primary particles of the inorganic fine particles is 5 to 200 nm, more preferably 10 to 150 nm, still more preferably 20 to 100 nm, and particularly preferably 20 to 50 nm.
In the hard coat layer, the inorganic fine particles are preferably dispersed as finely as possible.
The particle size of the inorganic fine particles in the hard coat layer is preferably 5 to 300 nm, more preferably 10 to 200 nm, more preferably 20 to 150 nm, and particularly preferably 20 to 80 nm in terms of average particle diameter.

  The content of the inorganic fine particles in the hard coat layer is preferably 10 to 90% by mass, more preferably 15 to 80% by mass, and particularly preferably 15 to 75% by mass with respect to the total mass of the hard coat layer.

  The film thickness of the hard coat layer can be appropriately designed depending on the application. The film thickness of the hard coat layer is preferably 0.2 to 10 μm, more preferably 0.5 to 7 μm, and particularly preferably 0.7 to 5 μm.

The strength of the hard coat layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher in a pencil hardness test according to JIS K5400.
Further, in the Taber test according to JIS K5400, the smaller the wear amount of the test piece before and after the test, the better.
In the formation of the hard coat layer, when formed by a crosslinking reaction or a polymerization reaction of an ionizing radiation curable compound, the crosslinking reaction or the polymerization reaction is preferably performed in an atmosphere having an oxygen concentration of 10% by volume or less. . By forming in an atmosphere having an oxygen concentration of 10% by volume or less, a hard coat layer excellent in physical strength and chemical resistance can be formed.
Preferably, it is formed by a crosslinking reaction or polymerization reaction of an ionizing radiation curable compound in an atmosphere having an oxygen concentration of 6% by volume or less, more preferably an oxygen concentration of 4% by volume or less, particularly preferably an oxygen concentration of 2 Volume% or less, most preferably 1 volume% or less.

As a method of reducing the oxygen concentration to 10% by volume or less, it is preferable to replace the atmosphere (nitrogen concentration of about 79% by volume, oxygen concentration of about 21% by volume) with another gas, particularly preferably replacement with nitrogen (nitrogen purge). It is to be.
The hard coat layer is preferably formed by applying a coating composition for forming a hard coat layer on the surface of the transparent support.

[Low refractive index layer]
The refractive index of the low refractive index layer of the antireflection film of the present invention is 1.20 to 1.49, preferably 1.30 to 1.44.

The material for forming the low refractive index layer will be described below.
The low refractive index layer of the present invention preferably contains a fluorine-containing polymer as a low refractive index binder. The fluoropolymer is preferably a fluoropolymer that is crosslinked by heat or ionizing radiation having a coefficient of dynamic friction of 0.03 to 0.15 and a contact angle with water of 90 to 120 °. As described above, an inorganic filler for improving the film strength can be used in the low refractive index layer of the present invention.

  Examples of the fluorine-containing polymer preferably used for the low refractive index layer include hydrolysis and dehydration condensates of perfluoroalkyl group-containing silane compounds (for example, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane). In addition, a fluorine-containing copolymer having a fluorine-containing monomer unit and a structural unit for imparting crosslinking reactivity as structural components may be mentioned.

  Specific examples of the fluorine-containing monomer unit include, for example, fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, perfluorooctylethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole. Etc.), partially (meth) acrylic acid or fully fluorinated alkyl ester derivatives (for example, Biscoat 6FM (manufactured by Osaka Organic Chemical), M-2020 (manufactured by Daikin), etc.), fully or partially fluorinated vinyl ethers, etc. However, perfluoroolefins are preferred, and hexafluoropropylene is particularly preferred from the viewpoints of refractive index, solubility, transparency, availability, and the like.

  As structural units for imparting crosslinking reactivity, structural units obtained by polymerization of monomers having a self-crosslinkable functional group in advance in the molecule such as glycidyl (meth) acrylate and glycidyl vinyl ether, carboxyl groups, hydroxy groups, amino groups , Obtained by polymerization of a monomer having a sulfo group or the like (for example, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, maleic acid, crotonic acid, etc.) And a structural unit obtained by introducing a crosslinking reactive group such as a (meth) acryloyl group into these structural units by a polymer reaction (for example, it can be introduced by a technique such as allowing acrylic acid chloride to act on a hydroxy group) And the like.

  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, vinyltoluene, 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.

  As described in JP-A-10-25388 and JP-A-10-147739, a curing agent may be appropriately used in combination with the above polymer.

  A particularly useful fluorine-containing polymer used in the low refractive index layer 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 cross-linking reactive group-containing polymer units preferably occupy 5 to 70 mol%, particularly preferably 30 to 60 mol% of the total polymer units of the polymer.

  As a preferable form of the copolymer used for the low refractive index layer, one of general formula 1 can be mentioned.

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

  In general formula 1, X represents a hydrogen atom or a methyl group. From the viewpoint of curing reactivity, a hydrogen atom is more preferable.

  In the general formula 1, A represents a repeating unit derived from an arbitrary vinyl monomer, and is not particularly limited as long as it is a constituent component of a monomer copolymerizable with hexafluoropropylene. Tg (contributes to film hardness), solubility in solvents, transparency, slipperiness, dust / antifouling properties, etc., can be selected as appropriate, depending on the purpose, depending on the single or multiple vinyl monomers It may be configured.

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

  x, y, and z represent mol% of each constituent component, and represent values satisfying 30 ≦ x ≦ 60, 5 ≦ y ≦ 70, and 0 ≦ z ≦ 65. Preferably, 35 ≦ x ≦ 55, 30 ≦ y ≦ 60, and 0 ≦ z ≦ 20, and particularly preferably 40 ≦ x ≦ 55, 40 ≦ y ≦ 55, and 0 ≦ z ≦ 10.

  As a particularly preferred form of the copolymer used for the low refractive index layer, the general formula 4 may be mentioned.

Formula 4

In the general formula 4, X, x, and y have the same meanings as X, x, and y in the general formula 1, and preferred ranges are also the same.
n represents an integer of 2 ≦ n ≦ 10, preferably 2 ≦ n ≦ 6, and particularly preferably 2 ≦ n ≦ 4.
B represents a repeating unit derived from an arbitrary vinyl monomer, and may be composed of a single composition or a plurality of compositions. As an example, what was demonstrated as an example of A in the said General formula 1 is applicable.
z1 and z2 represent mol% of each repeating unit, and represent values satisfying 0 ≦ z1 ≦ 65 and 0 ≦ z2 ≦ 65. It is preferable that 0 ≦ z1 ≦ 30 and 0 ≦ z2 ≦ 10 respectively, and it is particularly preferable that 0 ≦ z1 ≦ 10 and 0 ≦ z2 ≦ 5.

  For the copolymer represented by the general formula 1 or 4, for example, a (meth) acryloyl group is introduced into a copolymer comprising a hexafluoropropylene component and a hydroxyalkyl vinyl ether component by any one of the methods described above. Can be synthesized.

  Although the preferable example of the copolymer useful by this invention is shown below, this invention is not limited to these.

  The copolymer used for the low refractive index layer is synthesized by synthesizing precursors such as a hydroxyl group-containing polymer by various polymerization methods such as solution polymerization, precipitation polymerization, suspension polymerization, precipitation polymerization, bulk polymerization, and emulsion polymerization. Then, it can be carried out by introducing a (meth) acryloyl group by the polymer reaction. The polymerization reaction can be performed by a known operation such as a batch system, a semi-continuous system, or a continuous system.

  The polymerization initiation method includes a method using a radical initiator, a method of irradiating light or radiation, and the like. These polymerization methods and polymerization initiation methods are, for example, the revised version of Tsuruta Junji “Polymer Synthesis Method” (published by Nikkan Kogyo Shimbun, 1971), Takatsu Otsu, Masato Kinoshita, “Experimental Methods for Polymer Synthesis” It is described in pp. 47-154 published in 1972.

Among the above polymerization methods, a solution polymerization method using a radical initiator is particularly preferable. Solvents used in the solution polymerization method include, for example, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, tetrahydrofuran, dioxane, N, N-dimethylformamide, N, N-dimethylacetamide, benzene, toluene, acetonitrile, A single organic solvent such as methylene chloride, chloroform, dichloroethane, methanol, ethanol, 1-propanol, 2-propanol, and 1-butanol, or a mixture of two or more thereof may be used, or a mixed solvent with water may be used.
The method for synthesizing the copolymer of the present invention is described in detail in JP-A No. 2004-45462.

  The polymerization temperature needs to be set in relation to the molecular weight of the polymer to be produced, the type of initiator, etc., and can be from 0 ° C. or lower to 100 ° C. or higher, but it is preferable to carry out the polymerization in the range of 50 to 100 ° C.

The reaction pressure can be selected as appropriate, but usually it is preferably about 1 to 100 kg / cm ² , particularly about 1 to 30 kg / cm ² . The reaction time is about 5 to 30 hours.

  As the reprecipitation solvent for the obtained polymer, isopropanol, hexane, methanol and the like are preferable.

  The fluorine-containing polymer of the low refractive index layer is added in an amount of 20 to 95% by mass based on the solid content of the coating composition of the layer.

Next, the inorganic fine particles that can be contained in the low refractive index layer of the present invention are described below.
The amount of the inorganic fine particles is ^{preferably 1mg / m 2 ~100mg / m 2} , more preferably ^{5mg / m 2 ~80mg / m 2} , more preferably from ^{10mg / m 2 ~60mg / m 2} . When the blending amount is in the above range, the scratch resistance is excellent, the occurrence of fine irregularities on the surface of the low refractive index layer is reduced, and the appearance such as black tightening and the integrated reflectance are improved.
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. Examples thereof include fine particles of magnesium fluoride and silica. In particular, silica fine particles are preferable in terms of refractive index, dispersion stability, and cost. The average particle diameter of the silica fine particles 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, when the thickness of the low refractive index layer is 100 nm, the particle diameter of the silica fine particles is preferably 30 nm to 150 nm, more preferably 35 nm to 80 nm, and still more preferably 40 nm to 60 nm.
If the particle size of the silica fine particles is too small, the effect of improving the scratch resistance is reduced. If it 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. The silica fine particles may be either crystalline or amorphous, and may be monodispersed particles or aggregated particles as long as a predetermined particle size is satisfied. The shape is most preferably a spherical diameter, but there is no problem even if the shape is indefinite.
Here, the average particle diameter of the inorganic fine particles is measured by a Coulter counter.

  In order to further reduce the increase in the refractive index of the low refractive index layer, it is preferable to use hollow silica fine particles, and the hollow silica fine particles have a refractive index of 1.17 to 1.40, more preferably 1.17 to 1. .35, more 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, when the radius of the cavity in the particle is a and the radius of the particle shell is b, the porosity x calculated from the following formula (VIII) is preferably 10 to 60%, more preferably 20 to 60. %, Most preferably 30-60%.

Formula (VIII): x = (4πa 3/3) / (4πb 3/3) × 100

If 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 1.17. No rate particles are used.
The refractive index of these hollow silica particles was measured with an Abbe refractometer (manufactured by Atago Co., Ltd.).

In order to improve the dispersibility in the low refractive index layer, the hollow silica particles are dispersible by at least one of a hydrolyzate of organosilane represented by the general formula (5) described later and a partial condensate thereof. It is preferable that the improvement process is made. The same surface treatment can be applied to inorganic fine particles other than hollow silica particles.

Further, 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 “small size particle size silica particles”) is used as silica fine particles having the above particle size (“large size particles”). It is preferably used in combination with “silica fine particles having a diameter”.
Since the fine silica particles having a small particle size can exist in the gaps between the fine silica particles having a large particle size, they can contribute as a retaining agent for the fine silica particles having a large particle size.
When the low refractive index layer is 100 nm, the average particle size of the silica fine particles having a small size is preferably from 1 nm to 20 nm, more preferably from 5 nm to 15 nm, and particularly preferably from 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 with a 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 increase the affinity and binding to the binder component. Chemical surface treatment with a surfactant, a coupling agent, or the like may be performed. The use of a coupling agent is particularly preferred. As the coupling agent, an alkoxy metal compound (eg, titanium coupling agent, silane coupling agent) is preferably used. Of these, silane coupling treatment is particularly effective.
The above coupling agent is used as a surface treatment agent for the inorganic filler of the low refractive index layer in advance for surface treatment prior to the preparation of the layer coating solution. It is preferable to contain in a layer.
The silica fine particles are preferably dispersed in the medium in advance before the surface treatment in order to reduce the load of the surface treatment.
What has been described above for silica fine particles also applies to other inorganic fine particles.

At least one of the functional layers constituting the antireflection film of the present invention includes at least one component of an organosilane compound, a hydrolyzate thereof and a partial condensate thereof, a so-called sol, in the coating liquid forming the layer. It is preferable in terms of scratch resistance to contain a component (hereinafter sometimes referred to as such). In particular, the low refractive index layer preferably contains a sol component in order to achieve both antireflection ability and scratch resistance, and the hard coat layer also preferably contains a sol component. This sol component is condensed by a drying and heating process after coating the coating solution to form a cured product, which becomes a binder for the layer. Moreover, when this hardened | cured material has a polymerizable unsaturated bond, the binder which has a three-dimensional structure is formed by irradiation of actinic light.
The organosilane compound is preferably one represented by the following general formula 5.

Formula _{^{5: (R 10) m -Si}} (X 1) 4-m

In the above general formula 5, R ¹⁰ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. As an alkyl group, a C1-C30 alkyl group is preferable, More preferably, it is C1-C16, Most preferably, it is a C1-C6 thing. Specific examples of the alkyl group include methyl, ethyl, propyl, isopropyl, hexyl, decyl, hexadecyl and the like. Examples of the aryl group include phenyl and naphthyl, and a phenyl group is preferable.
X ¹ represents a hydroxyl group or a hydrolyzable group, for example, an alkoxy group (preferably an alkoxy group having 1 to 5 carbon atoms, such as a methoxy group or an ethoxy group), a halogen atom (for example, Cl, Br, I Etc.), and R ² COO (R ² is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, such as CH ₃ COO, C ₂ H ₅ COO, etc.). Is an alkoxy group, particularly preferably a methoxy group or an ethoxy group.
m represents an integer of 1 to 3, preferably 1 or 2, and particularly preferably 1.

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

When there are a plurality of R ^{10 s} , at least one is preferably a substituted alkyl group or a substituted aryl group, and among them, an organosilane compound having a vinyl polymerizable substituent represented by the following general formula 6 is preferable.
General formula 6

In the general formula 6, R ¹⁶ represents a hydrogen atom, a methyl group, a methoxy group, an alkoxycarbonyl group, a cyano group, a fluorine atom, or a chlorine atom. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group. A hydrogen atom, a methyl group, a methoxy group, a methoxycarbonyl group, a cyano group, a fluorine atom and a chlorine atom are preferred, a hydrogen atom, a methyl group, a methoxycarbonyl group, a fluorine atom and a chlorine atom are more preferred, and a hydrogen atom and a methyl group Is particularly preferred.
Y represents a single bond or * -COO-**, * -CONH-** or * -O-**, preferably a single bond, * -COO-** or * -CONH-**, * -COO-** is more preferred, and * -COO-** is particularly preferred. * Represents a position bonded to ═C (R ¹⁶ ) —, and ** represents a position bonded to L ¹ .

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

n represents 0 or 1. When X ¹ there are a plurality, may be different even multiple of X ¹ is the same, respectively. n is preferably 0.
R ¹⁰ has the same meaning as R ^{10 in} formula 5, and is preferably a substituted or unsubstituted alkyl group or an unsubstituted aryl group, more preferably an unsubstituted alkyl group or an unsubstituted aryl group.
X ¹ has the same meaning as X ^{1 in} formula 5, preferably a halogen atom, a hydroxyl group, or an unsubstituted alkoxy group, more preferably a chlorine atom, a hydroxyl group, or an unsubstituted alkoxy group having 1 to 6 carbon atoms, a hydroxyl group, a carbon A C 1-3 alkoxy group is more preferable, and a methoxy group is particularly preferable.

  Two or more of the compounds represented by general formulas 5 and 6 may be used in combination. Specific examples of the compounds represented by general formulas 5 and 6 are shown below, but are not limited thereto.

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

The hydrolyzate and / or partial condensate of the organosilane compound used in the present invention will be described in detail.
The hydrolysis reaction of organosilane and the subsequent condensation reaction are generally carried out in the presence of a catalyst. Catalysts include inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid; organic acids such as oxalic acid, acetic acid, formic acid, methanesulfonic acid and toluenesulfonic acid; inorganic bases such as sodium hydroxide, potassium hydroxide and ammonia; triethylamine, Examples thereof include organic bases such as pyridine; metal alkoxides such as triisopropoxyaluminum and tetrabutoxyzirconium; metal chelate compounds having a metal such as Zr, Ti or Al as a central metal. Among inorganic acids, hydrochloric acid, 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, or water of 3.0 or less. More preferred is an organic acid, hydrochloric acid, sulfuric acid, an organic acid having an acid dissociation constant of 2.5 or less in water is more preferred, an organic acid having an acid dissociation constant in water of 2.5 or less is more preferred, and methanesulfonic acid Further, oxalic acid, phthalic acid, and malonic acid are more preferable, and oxalic acid is particularly preferable.

The organosilane hydrolysis / condensation reaction can be carried out in the absence of a solvent or in a solvent, but an organic solvent is preferably used in order to mix the components uniformly. For example, alcohols, aromatic hydrocarbons, ethers, Ketones and esters are preferred.
The solvent preferably dissolves 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 alcohols include monohydric alcohols and dihydric alcohols, and 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, xylene and the like. Specific examples of ethers include tetrahydrofuran and dioxane. Specific examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, Specific examples of esters such as diisobutyl ketone include ethyl acetate, propyl acetate, butyl acetate, and propylene carbonate.
These organic solvents can be used alone or in combination of two or more. The concentration of the solid content in the reaction is not particularly limited, but is usually in the range of 1% to 90%, preferably in the range of 20% to 70%.

0.3 to 2 mol, preferably 0.5 to 1 mol of water is added to 1 mol of the hydrolyzable group of the organosilane, in the presence or absence of the above solvent, and in the presence of a catalyst. It is carried out by stirring at 25 to 100 ° C.
In the present invention, (wherein, ^{R 3} represents an alkyl group having 1 to 10 carbon atoms) Formula ^R 3 OH alcohol of the general formula ^R 4 COCH ₂ COR ⁵ (formula represented by, ^{R 4} is carbon From Zr, Ti, or Al having a ligand of a compound represented by an alkyl group having 1 to 10 carbon atoms, R ⁵ represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms) It is preferable to perform hydrolysis by stirring at 25 to 100 ° C. in the presence of at least one metal chelate compound having a selected metal as a central metal.

Metal chelate compounds (wherein, ^{R 3} represents an alkyl group having 1 to 10 carbon atoms) Formula ^R 3 OH alcohol and ^R 4 COCH ₂ COR ⁵ (wherein represented by, ^{R 4} is C 1 -C To 10 alkyl groups, R ⁵ represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms), and is selected from Zr, Ti, and Al. Any metal having a metal as a central metal 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 a general formula of Zr (OR ³ ) _p1 (R ⁴ COCHCOR ⁵ ) _p2 , Ti (OR ³ ) _q1 (R ⁴ COCHCOR ⁵ ) _q2 , and Al (OR ³ ) _r1 (R ⁴ Those selected from the group of compounds represented by COCHCOR ⁵ ) _r2 are preferred, and serve to promote the condensation reaction of the hydrolyzate and / or partial condensate of the organosilane compound.
R ³ and R ⁴ in the metal chelate compound may be the same or different and each is an alkyl group having 1 to 10 carbon atoms, specifically, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, sec -Butyl group, t-butyl group, n-pentyl group, phenyl group and the like. R ⁵ represents an alkyl group having 1 to 10 carbon atoms as described above, or an alkoxy group having 1 to 10 carbon atoms such as a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, and n-butoxy. Group, sec-butoxy group, t-butoxy group and the like. Moreover, p1, p2, q1, q2, r1, and r2 in the metal chelate compound represent integers determined so as to be p1 + p2 = 4, q1 + q2 = 4, and r1 + r2 = 3, respectively.

Specific examples of these metal chelate compounds include tri-n-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, diisopropyl Poxyacetylacetonate aluminum, isopropoxybis (ethylacetoacetate) aluminum, isopropoxybis (acetylacetonate) aluminum, tris (ethylacetoacetate) aluminum, tris (acetylacetonate) aluminum, monoacetylacetonate bis (ethyl) An aluminum chelate compound such as acetoacetate) aluminum.
Among these metal chelate compounds, tri-n-butoxyethyl acetoacetate zirconium, diisopropoxybis (acetylacetonate) 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 is preferably used in a proportion of 0.01 to 50% by mass, more preferably 0.1 to 50% by mass, and still more preferably 0.5 to 10% by mass with respect to the organosilane compound. If it is less than 0.01% by mass, the condensation reaction of the organosilane compound is slow, and the durability of the coating film may be deteriorated. On the other hand, if it exceeds 50% by mass, the hydrolyzate and / or partial condensate of the organosilane compound And the storage stability of the composition containing the metal chelate compound may be deteriorated, which is not preferable.

  In addition to the composition containing the sol component and the metal chelate compound, a β-diketone compound and / or a β-ketoester compound is added to the coating liquid for the hard coat layer or low refractive index layer used in the present invention. Is preferred. This will be further described below.

The β-diketone compound and / or β-ketoester compound represented by the general formula R ⁴ COCH ₂ COR ⁵ is used in the present invention, and acts as a stability improver for the composition used in the present invention. Is. That is, by coordinating with a metal atom in the metal chelate compound (zirconium, titanium and / or aluminum compound), the condensation reaction of the hydrolyzate and / or partial condensate of the organosilane compound by these metal chelate compounds is performed. It is considered that the promoting action is suppressed and the storage stability of the resulting composition is improved. R ⁴ and R ⁵ constituting the β- diketone compound and / or β- ketoester compound are the same as R ⁴ and R ⁵ constituting the metal chelate compound.

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

The content of the hydrolyzate and / or partial condensate of the organosilane compound is preferably small for a surface layer that is a relatively thin film and large for a lower layer that is a thick film. In the case of a surface layer such as a low refractive index layer, 0.1 to 50% by mass of the total solid content of the containing layer (addition layer) is preferable, 0.5 to 20% by mass is more preferable, and 1 to 10% by mass is preferable. Most preferred.
The amount added to the layers other than the low refractive index layer is preferably 0.001 to 50 mass%, more preferably 0.01 to 20 mass%, and more preferably 0.05 to 10 mass% of the total solid content of the containing layer (addition layer). More preferably, it is 0.1 to 5% by mass.
In the present invention, first, a composition containing a hydrolyzate and / or partial condensate of the organosilane compound and a metal chelate compound is prepared, and a liquid in which a β-diketone compound and / or a β-ketoester compound is added thereto is prepared. It is preferable to coat by coating it in at least one coating solution of a hard coat layer or a low refractive index layer.

  In the low refractive index layer, the amount of the organosilane sol component used with respect to the fluorine-containing polymer is preferably from 5 to 100% by mass, and preferably from 5 to 40% by mass considering the effect, refractive index, film shape / surface shape, etc. % Is more preferable, 8-35 mass% is further more preferable, and 10-30 mass% is especially preferable.

  In the present invention, for the purpose of suppressing aggregation and sedimentation of the inorganic filler, it is also preferable to use a dispersion stabilizer in combination with the coating solution for forming each layer. As the dispersion stabilizer, polyvinyl alcohol, polyvinyl pyrrolidone, cellulose derivative, polyamide, phosphate ester, polyether, surfactant, silane coupling agent, titanium coupling agent and the like can be used. In particular, the above-mentioned silane coupling agent is preferable because the film after curing is strong.

  The composition for forming a low refractive index layer of the present invention is usually prepared in the form of a liquid, with the copolymer as a preferred constituent, and by dissolving various additives and a radical polymerization initiator in an appropriate solvent as necessary. Is done. At this time, the concentration of the solid content is appropriately selected according to the use, but is generally about 0.01 to 60% by mass, preferably 0.5 to 50% by mass, particularly preferably 1% to 20% by mass. %.

  As described above, it is not always advantageous to add an additive such as a curing agent from the viewpoint of film hardness of the low refractive index layer, but from the viewpoint of interfacial adhesion with the high refractive index layer, etc. ) A curing agent such as an acrylate compound, polyfunctional epoxy compound, polyisocyanate compound, aminoplast, polybasic acid or anhydride thereof, or a small amount of inorganic fine particles such as silica can be added. When adding these, it is preferable that it is the range of 0-30 mass% with respect to the total solid of a low refractive index layer membrane | film | coat, It is more preferable that it is the range of 0-20 mass%, 0-10 mass % Range is particularly preferred.

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

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

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

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

[Transparent support]
As the transparent support of the antireflection film of the present invention, a plastic film is preferably used. 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-based resin (Arton: trade name, manufactured by JSR Corporation), amorphous polyolefin (ZEONEX: trade name, manufactured by Nippon Zeon Corporation), and the like. Of these, triacetyl cellulose, polyethylene terephthalate, and polyethylene naphthalate are preferable, and triacetyl cellulose is particularly preferable.
Triacetyl cellulose consists of a single layer or a plurality of layers. A single-layer triacetyl cellulose is produced by drum casting or band casting disclosed in JP-A-7-11055 and the like. It is prepared by the so-called co-casting method disclosed in Japanese Patent Application Laid-Open Nos. 61-94725 and 62-43846. That is, the raw material flakes are solvents such as halogenated hydrocarbons (dichloromethane, alcohols (methanol, ethanol, butanol, etc.), esters (methyl formate, methyl acetate, etc.), ethers (dioxane, dioxolane, diethyl ether, etc.), etc. A solution (called a dope) with various additives such as a plasticizer, an ultraviolet absorber, an anti-degradation agent, a slipping agent, and a peeling accelerator is added to the horizontal endless as necessary. When casting by a dope supply means (called a die) on a support composed of a metal belt or a rotating drum, a single dope is cast in a single layer if it is a single layer, and a high concentration in the case of multiple layers. A low-concentration dope is co-cast on both sides of the cellulose ester dope, and the film is dried to some extent on the support to release the rigid film, and then peeled off from the support. A process comprising passed through a drying section by species of the conveying means to remove the solvent.

A typical solvent for dissolving triacetyl cellulose as described above is dichloromethane. However, from the viewpoint of the global environment and working environment, the solvent preferably does not substantially contain a halogenated hydrocarbon such as dichloromethane. “Substantially free” means that the proportion of halogenated hydrocarbon in the organic solvent is less than 5% by mass (preferably less than 2% by mass).
In preparing a triacetyl cellulose dope using a solvent substantially free of dichloromethane or the like, a special dissolution method as described later is essential.

  The first dissolution method is called a cooling dissolution method and will be described below. First, triacetyl cellulose is gradually added to a solvent at a temperature around room temperature (-10 to 40 ° C.) while stirring. The mixture is then cooled to -100 to -10 ° C (preferably -80 to -10 ° C, more preferably -50 to -20 ° C, most preferably -50 to -30 ° C). The cooling can be performed, for example, in a dry ice / methanol bath (−75 ° C.) or a cooled diethylene glycol solution (−30 to −20 ° C.). When cooled in this manner, the mixture of triacetyl cellulose and solvent solidifies. Furthermore, when this is heated to 0 to 200 ° C. (preferably 0 to 150 ° C., more preferably 0 to 120 ° C., most preferably 0 to 50 ° C.), a solution in which triacetyl cellulose flows in the solvent is obtained. The temperature may be increased by simply leaving it at room temperature or in a warm bath.

  The second method is called a high temperature melting method and will be described below. First, triacetyl cellulose is gradually added to a solvent at a temperature around room temperature (-10 to 40 ° C.) while stirring. The triacetyl cellulose solution of the present invention is preferably swollen beforehand by adding triacetyl cellulose to a mixed solvent containing various solvents. In this method, the dissolution concentration of triacetyl cellulose is preferably 30% by mass or less, but is preferably as high as possible from the viewpoint of drying efficiency during film formation. Next, the organic solvent mixed solution is heated to 70 to 240 ° C. under a pressure of 0.2 MPa to 30 MPa (preferably 80 to 220 ° C., more preferably 100 to 200 ° C., most preferably 100 to 190 ° C.). Next, since these heated solutions cannot be applied as they are, it is necessary to cool them below the lowest boiling point of the solvent used. In that case, it is common to cool to -10-50 degreeC and to return to a normal pressure. For cooling, the high-pressure and high-temperature vessel or line containing the triacetylcellulose solution may be left at room temperature, and more preferably, the apparatus may be cooled using a coolant such as cooling water. A cellulose acetate film substantially free of halogenated hydrocarbons such as dichloromethane and a process for producing the same are disclosed in JIII Journal of Technical Disclosure (Publication No. 2001-1745, published on March 15, 2001, hereinafter Published Technical Report 2001-1745). (Abbreviated as No.).

[Formation of optical functional layer]
The optical functional layer is applied by a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a die coating method, a wire bar coating method, a gravure coating method or an extrusion coating method (described in US Pat. No. 2,681,294). However, it is preferable to apply by a die coating method, and it is more preferable to apply using a new die coater described later. Two or more layers may be applied simultaneously. The method of simultaneous application is 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).
In the optical functional film of the present invention, it is also desired that there are few bright spot defects. The bright spot defect in the present invention is a defect that can be seen by reflection on the coating film, and can be detected by an operation such as black coating on the back surface of the optical functional film after coating. The bright spot defects that can be visually observed are generally 50 μm or more. When there are many bright spot defects, the yield at the time of manufacture falls, and a large-area antireflection film cannot be manufactured.
In the optical functional film of the present invention, the number of bright spot defects is 20 or less per square meter, preferably 10 or less, more preferably 5 or less, and particularly preferably 1 or less.

In order to continuously produce the optical functional film of the present invention, a process of continuously feeding a roll-shaped support film, a process of applying and drying a coating liquid, a process of curing a coating film, and a support having a cured layer A step of winding the body film is performed.
The film support is continuously sent from the roll-shaped film support to the clean room, and the static electricity charged on the film support is removed by the electrostatic charge-off device in the clean room, and then the film support adheres on the film support. Remove the foreign material that has been removed with a dust remover. Subsequently, the coating solution is applied onto the film support in the application section installed in the clean room, and the applied film support is sent to the drying chamber and dried.
The film support having the dried coating layer is sent from the drying chamber to the radiation curing chamber, irradiated with radiation, and the monomer contained in the coating layer is polymerized and cured. Furthermore, the film support having a layer cured by radiation can be sent to the thermosetting section and heated to complete the curing. The film support having a layer that has been cured is wound into a roll.

The above process may be performed every time each layer is formed, or a plurality of coating units-drying chambers-radiation curing units-thermosetting chambers may be provided to form each layer continuously. In view of the above, it is preferable to continuously form each layer. An example of the configuration of an apparatus for continuously applying each layer is shown in FIG. The apparatus has a necessary number of film forming units 100, 200, 300, 400 installed between Step 1 for continuously feeding a roll-shaped support film and Step 2 for winding the roll-shaped support film. Is. The apparatus shown in FIG. 2 is an example of a configuration in which four layers are continuously applied without winding up, but it is of course possible to change the number of film forming units according to the layer configuration. The film forming unit 100 includes a process 101 for applying a coating liquid, a process 102 for drying a coating film, and a process 103 for curing the coating film. The film forming units 200, 300, and 400 are similarly configured.
For example, in the case of a three-layer thin film interference type antireflection film having different refractive indexes, a roll-shaped support film coated with the hard coat layer is continuously formed using an apparatus having three film forming units. It is more preferable to wind up after coating the delivery layer, the middle refractive index layer, the high refractive index layer, and the low refractive index layer sequentially in each film forming unit, and four film forming units are installed so as to be sequentially coatable. Using the apparatus shown in Fig. 4, a roll-shaped support film is continuously fed out, and a hard coat layer, a medium refractive index layer, a high refractive index layer, and a low refractive index layer are sequentially coated on each film forming unit and wound up. More preferred.
In order to produce an antireflection film with few bright spot defects in the present invention, the dispersibility of particles and fine particles dispersed in the layer can be improved, and a microfiltration operation of the coating liquid can be mentioned. At the same time, each layer forming the antireflection layer is subjected to a dust process on the film before the coating process in the coating unit and the drying process performed in the drying chamber are performed in a high clean air atmosphere, and before the coating is performed. It is preferable that dust is sufficiently removed. The air cleanliness of the coating process and the drying process is desirably class 100 (353 particles (0.5 μm or more) / (cubic meter) or less) of class 100 or more based on the standard of air cleanliness in US Federal Standard 209E. Preferably it is Class 10 or higher, more preferably Class 1 (35.5 particles / (cubic meter) or lower, 0.5 μm or more) or more. Moreover, it is more preferable that the degree of air cleanliness is high also in the feeding and winding parts other than the coating-drying process.

As a dust removal method used in a dust removal step as a pre-process for coating, a method of pressing a nonwoven fabric, a blade or the like against the film surface described in JP-A-59-150571, described in JP-A-10-309553 Highly clean air is blown at a high speed to peel off the deposit from the film surface, and suction is performed at a suction port adjacent to the film. Ultrasonic-vibrated compressed air described in JP-A-7-333613 is sprayed onto the deposit. And a dry dust removal method such as a method of peeling and suctioning (manufactured by Shinkosha, New Ultra Cleaner, etc.).
In addition, a method of introducing a film into a cleaning tank and peeling off the adhered material by an ultrasonic vibrator, supplying a cleaning liquid to the film described in Japanese Patent Publication No. 49-13020, and then blowing and sucking high-speed air As described in JP-A-2001-38306, a wet dust removal method such as a method in which the web is continuously rubbed with a roll wetted with a liquid and then the liquid is sprayed onto the rubbed surface to be washed. Can do. Among such dust removal methods, a method using ultrasonic dust removal or a method using wet dust removal is particularly preferable from the viewpoint of dust removal effect.

  In addition, it is particularly preferable to remove static electricity on the film support before performing such a dust removal step from the viewpoint of increasing dust removal efficiency and suppressing adhesion of dust. As such a static elimination method, a corona discharge ionizer, a light irradiation ionizer such as UV or soft X-ray, or the like can be used. The charged voltage of the film support before and after dust removal and coating is desirably 1000 V or less, preferably 300 V or less, and particularly preferably 100 V or less.

[filtration]
The coating solution used for coating is preferably filtered before coating. As a filter for filtration, it is preferable to use a filter having a pore diameter as small as possible within a range in which components in the coating solution are not removed. For filtration, a filter having an absolute filtration accuracy of 0.1 to 10 μm is used, and a filter having an absolute filtration accuracy of 0.1 to 5 μm is preferably used. The thickness of the filter is preferably 0.1 to 10 mm, and more preferably 0.2 to 2 mm. In that case, the filtration pressure is preferably 15 kg / cm ² or less, more preferably 10 kg / cm ² or less, and further preferably 2 kg / cm ² or less.
The filtration filter member is not particularly limited as long as it does not affect the coating solution. Specifically, the same thing as the filtration member of the wet dispersion of an inorganic compound mentioned above is mentioned.
It is also preferable to ultrasonically disperse the filtered coating solution immediately before coating to assist defoaming and dispersion holding of the dispersion.

In the present invention, the method for curing each layer of the antireflection film is preferably formed by a crosslinking reaction or a polymerization reaction at the same time as or after application of the coating composition by light irradiation, electron beam irradiation or heating. .
When each layer of the antireflection film is formed by a crosslinking reaction or a polymerization reaction of an ionizing radiation curable compound, the crosslinking reaction or the polymerization reaction is preferably performed in an atmosphere having an oxygen concentration of 10% by volume or less. By forming in an atmosphere having an oxygen concentration of 10% by volume or less, an outermost layer excellent in physical strength and chemical resistance can be obtained.
The oxygen concentration is preferably 5% by volume or less, more preferably 1% by volume or less, particularly preferably the oxygen concentration is 0.5% by volume or less, and most preferably 0.1% by volume or less.

  As a method of reducing the oxygen concentration to 10% by volume or less, it is preferable to replace the atmosphere (nitrogen concentration of about 79% by volume, oxygen concentration of about 21% by volume) with another gas, particularly preferably replacement with nitrogen (nitrogen purge). It is to be.

The light source for light irradiation may be any one in the ultraviolet light region or near infrared light. Ultraviolet, high pressure, medium pressure and low pressure mercury lamps, chemical lamps, carbon arc lamps, metal halide lamps may be used as ultraviolet light sources. Xenon lamps, sunlight, etc. Various available laser light sources having a wavelength of 350 to 420 nm may be irradiated as a multi-beam. Further, examples of the near-infrared light source include a halogen lamp, a xenon lamp, and a high-pressure sodium lamp.
When a near infrared light source is used, it may be used in combination with an ultraviolet light source, or light may be irradiated from the substrate surface side opposite to the coating surface side. Film curing in the depth direction in the coating layer proceeds without delay with the vicinity of the surface, and a cured film having a uniform cured state is obtained.
Irradiation intensity of ultraviolet irradiation is preferably about 0.1~1000mW / cm ^2, irradiation amount on the coating film surface is preferably 10~1000mJ / cm ^2. Further, the temperature distribution of the coating film in the light irradiation step is preferably as uniform as possible, preferably within ± 3 ° C., and more preferably controlled within ± 1.5 ° C. In this range, the polymerization reaction in the in-plane and in-layer depth directions of the coating film proceeds uniformly, which is preferable.

[Configuration of die coater]
FIG. 3 is a sectional view of a coater using a slot die embodying the present invention. The coater 10 is applied to the web W continuously supported by the backup roll 11 by applying the coating liquid 14 from the slot die 13 as beads 14a, thereby forming a coating film 14b on the web WW.

  Inside the slot die 13, a pocket 15 and a slot 16 are formed. The pocket 15 has a curved section and a straight section, and may be substantially circular as shown in FIG. 3, for example, or semicircular. The pocket 15 is a liquid storage space for the coating liquid extended in the width direction of the slot die 13 with its cross-sectional shape, and the length of the effective extension is generally equal to or slightly longer than the coating width. The supply of the coating liquid 14 to the pocket 15 is performed from the side surface of the slot die 13 or from the center of the surface opposite to the slot opening 16a. The pocket 15 is provided with a stopper that prevents the coating liquid 14 from leaking out.

  The slot 16 is a flow path of the coating liquid 14 from the pocket 15 to the web W, and has a cross-sectional shape in the width direction of the slot die 13 similarly to the pocket 15, and the opening 16a located on the web side is generally Using a width regulating plate (not shown), the width is adjusted to be approximately the same as the coating width. The angle between the slot tip of the slot 16 and the tangent in the web running direction of the backup roll 11 is preferably 30 ° or more and 90 ° or less.

  The tip lip 17 of the slot die 13 where the opening 16a of the slot 16 is located is tapered, and the tip is a flat part 18 called a land. In the land 18, the upstream side in the traveling direction of the web W with respect to the slot 16 is referred to as an upstream lip land 18 a and the downstream side is referred to as a downstream lip land 18 b.

  4A and 4B show the cross-sectional shape of the slot die 13 in comparison with the conventional one. FIG. 4A shows the slot die 13 used in the present invention, and FIG. 4B shows the conventional slot die 30. In the conventional slot die 30, the distance between the upstream lip land 31a and the web W of the downstream lip land 31b is equal. Reference numeral 32 denotes a pocket, and 33 denotes a slot. On the other hand, in the slot die 13 of the present invention, the downstream side lip land length ILO is shortened, so that application with a wet film thickness of 20 μm or less can be performed with high accuracy.

The land length I _UP of the upstream lip land 18a is not particularly limited, but is preferably used in the range of 500 μm to 1 mm. The land length I _LO of the downstream lip land 18b is not less than 30 μm and not more than 100 μm, preferably not less than 30 μm and not more than 80 μm, more preferably not less than 30 μm and not more than 60 μm. If the land length I _LO of the downstream lip is shorter than 30 μm, the edge or land of the tip lip is likely to be chipped, streaks are likely to occur in the coating film, and consequently application is impossible. In addition, it becomes difficult to set the position of the wetting line on the downstream side, and there is a problem that the coating liquid tends to spread on the downstream side. It has been conventionally known that this spreading of the coating liquid on the downstream side means non-uniform wetting lines and leads to a problem of causing a defective shape such as a streak on the coating surface. On the other hand, when the land length I _LO of the downstream lip is longer than 100 μm, the bead itself cannot be formed, so that it is impossible to apply the thin layer.

  Further, the downstream lip land 18b has an overbite shape closer to the web W than the upstream lip land 18a. Therefore, the degree of decompression can be lowered, and a bead suitable for thin film coating can be formed. The difference in distance between the downstream side lip land 18b and the web W of the upstream side lip land 18a (hereinafter referred to as overbit length LO) is preferably 30 μm or more and 120 μm or less, more preferably 30 μm or more and 100 μm or less, and most preferably 30 μm. It is 80 μm or less. When the slot die 13 has an overbite shape, the gap GL between the tip lip 17 and the web W indicates the gap between the downstream lip land 18b and the web W.

FIG. 5 is a perspective view showing a slot die and its periphery in a coating process in which the present invention is implemented. On the opposite side of the web W in the direction of travel, the decompression chamber 40 is installed at a position where it does not come into contact with the bead 14a so that sufficient decompression adjustment can be performed. The decompression chamber 40 is provided with a back plate 40a and a side plate 40b for maintaining its operating efficiency, and there are gaps G _B , G between the back plate 40a and the web W and between the side plate 40b and the web W, respectively. _S exists. 6 and 7 are cross-sectional views showing the decompression chamber 40 and the web W that are close to each other. The side plate and the back plate may be integrated with the chamber body as shown in FIG. 6, or may be structured such that the gap is appropriately changed as shown in FIG. In any structure, portions that are actually opened between the back plate 40a and the web W and between the side plate 40b and the web W are defined as gaps G _B and G _S , respectively. The gap G _B between the back plate 40a and the web W of the decompression chamber 40, when the vacuum chamber 40 is installed beneath the web W and the slot die 13 as shown in FIG. 5, the uppermost end of the back plate 40a to the web W Indicates the gap.

It is preferable that the gap GB between the back plate 40a and the web W be set larger than the gap _GL between the tip lip 17 of the slot die 13 and the web W, so that the vicinity of the bead due to the eccentricity of the backup roll 11 can be obtained. A change in the degree of decompression can be suppressed. For example, when the gap G _L between the end lip 17 and the web W2 of the slot die 13 is 30μm or more 100μm or less, the gap G _B between the back plate 40a and the web W is preferably 100μm or 500μm or less.

[Material and accuracy]
The longer the length of the tip lip on the traveling direction side of the web in the web traveling direction, the more disadvantageous it is for bead formation.If this length varies between arbitrary locations in the slot die width direction, It becomes unstable. Therefore, it is preferable that the fluctuation width in the slot die width direction is within 20 μm.

  In addition, as for the material of the tip lip of the slot die, if a material such as stainless steel is used, the length of the slot die tip lip in the web running direction is 30 μm to 100 μm as described above. Even within this range, the accuracy of the tip lip cannot be satisfied. Therefore, in order to maintain a high processing accuracy, it is important to use a cemented carbide material as described in Japanese Patent No. 2810753. Specifically, at least the tip lip of the slot die is preferably made of a cemented carbide formed by bonding carbide crystals having an average particle size of 5 μm or less. Cemented carbides include carbide crystal particles such as tungsten carbide (hereinafter referred to as WC) bonded by a bonding metal such as cobalt, and other bonding metals include titanium, tantalum, niobium, and mixed metals thereof. Can also be used. The average particle size of the WC crystal is more preferably 3 μm or less.

  In order to realize high-precision coating, the length of the land on the web traveling direction side of the tip lip and the variation in the slot die width direction of the gap with the web are also important factors. It is desirable to achieve a combination of these two factors, that is, straightness within a range in which the fluctuation range of the gap can be suppressed to some extent. Preferably, the straightness of the tip lip and the backup roll is set so that the fluctuation width of the gap in the slot die width direction is 5 μm or less.

[Application speed]
By achieving the accuracy of the backup roll and the tip lip as described above, the coating method of the present invention has high film thickness stability during high-speed coating. Furthermore, since the coating method of the present invention is a pre-measuring method, it is easy to ensure a stable film thickness even during high-speed coating. The coating method of the present invention can be applied at high speed and with good film thickness stability to a coating solution having a low coating amount such as the antireflection film of the present invention. Although coating is possible with other coating methods, the dip coating method inevitably causes vibration of the coating liquid in the liquid receiving tank, and stepped unevenness is likely to occur. In the reverse roll coating method and the micro gravure method, stepped unevenness is likely to occur due to roll eccentricity and deflection related to coating. Also, in the microgravure method, uneven coating amount tends to occur due to the manufacturing accuracy of the gravure roll and the change of the roll and the blade due to the contact between the blade and the gravure roll. In addition, since these coating methods are post-measuring methods, it is difficult to ensure a stable film thickness. By using the production method of the present invention, coating at 25 m / min or more is preferable from the viewpoint of productivity.

  When the antireflection 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 triacetylcellulose, triacetylcellulose 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 antireflection film of the present invention as it is for the protective film.

When the antireflection 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, it is on a transparent support for sufficient 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, so it is difficult for dust to enter between the deflection film and the antireflection film when bonded to the deflection film, thus preventing point defects due to dust. It is valid.
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 problem that the treatment liquid becomes dirty 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 the formation of the antireflection layer on the transparent support, the alkaline liquid is applied to the surface of the antireflection film opposite to the surface on which the antireflection film is formed, and is heated, washed and / or washed. By summing, only the back surface of the film is saponified.

The antireflection 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 of 3.0% or less, preferably Is 2.5% or less.
When the antireflection film of the present invention has a haze value and an average reflectance in the above range, good antiglare properties and antireflection properties can be obtained without causing deterioration of the transmitted image.

  The polarizing plate is mainly composed of two protective films that sandwich the polarizing film from both sides. The antireflection film of the present invention is preferably used for at least one of the two protective films sandwiching the polarizing film from both sides. Since the antireflection film of the present invention also serves as a protective film, the production cost of the polarizing plate can be reduced. Further, by using the antireflection 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, with 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 film is such that the difference in the traveling speed in the longitudinal direction of the holding device is within 3%, and the angle formed by the film traveling direction 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 °. It can be manufactured by a stretching method in which the film traveling direction is bent while both ends are held. In particular, those inclined by 45 ° 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.
Of the two protective films of the polarizer, the film other than the antireflection film is preferably an optical compensation film having an optical compensation layer comprising an optically anisotropic layer. The optical compensation film (retardation film) can improve the viewing angle characteristics of the liquid crystal display screen.
A known film can be used as the optical compensation film. However, in terms of widening the viewing angle, an optical compensation layer made of a compound having a discotic structural unit described in JP-A-2001-100042 is provided. An optical compensation film characterized in that the angle formed by the discotic compound and the support is changed in the depth direction of the layer is preferable.
The angle preferably increases as the distance from the support surface side of the optically anisotropic layer increases.

  The antireflection film of the present invention can be applied to an image display device such as a liquid crystal display device (LCD), a plasma display panel (PDP), an electroluminescence display (ELD), or a cathode ray tube display device (CRT). Since the antireflection film of the present invention has a transparent support, the transparent support side is adhered to the image display surface of the image display device.

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

  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).

  Particularly 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 the viewing angle is used as a protective film having two polarizing films on both sides. Of these, a polarizing plate having an antireflection effect and a viewing angle widening effect can be obtained with the thickness of one polarizing plate by using it on the surface opposite to the antireflection film of the present invention.

  In order to describe the present invention in detail, examples will be described below, but the present invention is not limited thereto. Unless otherwise specified, “part” and “%” are based on mass.

(Preparation of sol solution a)
In a reactor equipped with a stirrer and a reflux condenser, 120 parts of methyl ethyl ketone, 100 parts of acryloyloxypropyltrimethoxysilane (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.), diisopropoxyaluminum ethyl acetoacetate (Kelope EP- 12, 3 parts of Hope Pharmaceutical Co., Ltd.) were added and mixed, 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%. Further, from the gas chromatography analysis, the raw material acryloyloxypropyltrimethoxysilane did not remain at all.

(Preparation of sol liquid b)
After cooling to room temperature after the reaction, a sol liquid b was obtained in the same manner as in the sol composition a except that 6 parts of acetylacetone was added.
The present invention will be described in more detail based on examples, but the present invention is not limited thereto.
(Synthesis of ultrahigh molecular weight polyethyl methacrylate (P-1))
To a 1000 mL three-necked flask equipped with a stirrer, a monomer supply tank, a thermometer, a cooling pipe, and a nitrogen gas introduction pipe, 1.32 g of sodium oleate and 0.18 g of sodium hydrogen carbonate are added to 332 g of distilled water, and under a nitrogen atmosphere. Heated to 65 ° C. Next, 38 mg of potassium persulfate was dissolved in 30 g of distilled water and added, and stirred for 30 minutes. Subsequently, 132 g of ethyl methacrylate was added dropwise over 5.5 hours. After completion of the dropwise addition, stirring was continued for 6 hours. After cooling to room temperature and filtering insoluble matter, it was added dropwise to 0.05 mol / dm ³ of dilute sulfuric acid and stirred for 1 hour. The precipitated solid was filtered, sufficiently washed with water, and then dried under reduced pressure to obtain P-2. In the molecular weight measurement by gel permeation chromatography (GPC) using a tetrahydrofuran solvent, the weight average molecular weight in terms of polystyrene was 2.0 × 10 ⁶ .

(Preparation of coating solution A for antiglare hard coat layer)
50 g of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (PET-30, manufactured by Nippon Kayaku Co., Ltd.) was diluted with 38.5 g of toluene. Further, 2 g of a polymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) was added and mixed 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% toluene dispersion of polystyrene particles having an average particle size of 3.5 μm (refractive index 1.61, SX-350, manufactured by Soken Chemical Co., Ltd.) dispersed in this solution for 20 minutes at 10,000 rpm with a Polytron disperser is 1 13.3 g of 30% toluene dispersion of acrylic styrene particles (refractive index 1.55, manufactured by Soken Chemical Co., Ltd.) having an average particle diameter of 3.5 μm and 0.7 g and finally a silane coupling agent (KBM- 5103, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to prepare a finished solution.
The mixture solution was filtered through a polypropylene filter having a pore size of 30 μm to prepare a coating solution A for an antiglare hard coat layer.

(Preparation of coating solution B for light diffusion layer)
Commercially available zirconia-containing UV-curable hard coat solution (DESOLITE Z7404, JSR (Co., Ltd.), a solid concentration of about 61%, an average particle diameter 20nm of ZrO _2, in the solid ZrO ₂ content: about 70%, polymerizable monomer, polymerization 285 g of initiator) and 85 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku Co., Ltd.) were mixed, and further diluted with 60 g of methyl isobutyl ketone and 17 g of methyl ethyl ketone. Furthermore, 28 g of a silane coupling agent (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.) was mixed and stirred. The refractive index of the coating film obtained by applying this solution and curing with ultraviolet rays was 1.61.
Further, a 30% methyl isobutyl ketone dispersion of classified strengthened crosslinked PMMA particles (refractive index: 1.49, MXS-300, manufactured by Soken Chemical Co., Ltd.) having an average particle size of 3.0 μm was added to this solution at 10,000 rpm with a Polytron disperser. 35 g of a dispersion dispersed for 20 minutes was added, and then a 30% methyl ethyl ketone dispersion of silica particles having an average particle diameter of 1.5 μm (refractive index 1.46, Seahosta KE-P150, manufactured by Nippon Shokubai Co., Ltd.) 90 g of a dispersion dispersed at 10,000 rpm for 30 minutes was added to obtain a finished solution.
The mixture solution was filtered through a polypropylene filter having a pore size of 30 μm to prepare a coating solution B for the light diffusion layer.

(Adjustment of coating solution A for low refractive index layer)
Thermally crosslinkable fluorine-containing polymer having a refractive index of 1.42 (JN7228, solid content concentration 6%, manufactured by JSR Corporation) 13 g, colloidal silica dispersion MEK-ST-L (silica, average particle size 45 nm, solid content concentration 30) %, Manufactured by Nissan Chemical Co., Ltd.) and 0.6 g of sol solution a were added, and then methyl ethyl ketone and 0.6 g of cyclohexano were added to adjust the solid content concentration to 3.5% by mass. The ratio of methyl ethyl ketone and cyclohexanone in the coating solution was 94: 6. After stirring, the mixture was filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating solution A for low refractive index layer.

(Preparation of hollow silica dispersion)
Hollow silica fine particle sol (particle size of about 40 to 50 nm, shell thickness of 6 to 8 nm, refractive index of 1.31, solid content concentration of 20%, main solvent isopropyl alcohol, particles according to Preparation Example 4 of JP 2002-79616 A 500 parts with acryloyloxypropyltrimethoxysilane (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.), and diisopropoxyaluminum ethyl acetoacetate (Kerope EP-12, Hope Pharmaceutical ( 9 parts of ion-exchanged water was added after adding and mixing 1.5 parts). After reacting at 60 ° C. for 8 hours, the mixture was cooled to room temperature, and 1.8 parts of acetylacetone was added. While adding 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 the solid content concentration was adjusted to 20% by mass with cyclohexanone was 5 mPa · s at 25 ° C. When the residual amount of isopropyl alcohol in the obtained dispersion A-1 was analyzed by gas chromatography, it was 1.5%.

(Preparation of coating solution B for low refractive index layer)
In the preparation of the coating liquid A for the low refractive index layer, the low refractive index layer was prepared in the same manner as the coating liquid A including the addition amount except that 1.95 g of the hollow silica dispersion was used instead of the colloidal silica dispersion. Coating solution B was prepared.

(Adjustment of coating solution for low refractive index layer with viscosity modifier)
Viscosity modifiers 1 to 5 and comparative additives were added to the low refractive index coating solutions A and B to prepare coating solutions containing a viscosity modifier shown in Table 1.
Viscosity modifier 1: Ultra high molecular weight polyethyl methacrylate (P-1)
Viscosity modifier 2: Polymethyl methacrylate (molecular weight: 996,000) manufactured by Sigma-Aldrich Japan
Viscosity modifier 3: Organic smectite STN (Organized product) manufactured by Coop Chemical Co., Ltd.
Viscosity modifier 4: Organized smectite SEN (Organized product) manufactured by Coop Chemical Co., Ltd.
Viscosity modifier 5: Organized smectite SAN (organized product) manufactured by Co-op Chemical Co., Ltd.
Comparative additive: Synthetic smectite SWN manufactured by Corp Chemical Co., Ltd.

[Example 1: Preparation and evaluation of inventive samples 1 to 12 and comparative samples 1 to 4 of an antireflection film]
(1) Application of functional layer Application of antiglare hard coat layer

(Die coater configuration)

The slot die 13 has an upstream lip land length I _UP of 0.5 mm, a downstream lip land length I _LO of 50 μm, a length of the opening of the slot 16 in the web running direction of 150 μm, and a length of the slot 16 of 50 mm. I used something. The gap between the upstream lip land 18a and the web WW is 50 μm longer than the gap between the downstream lip land 18b and the web WW (hereinafter referred to as an overbite length of 50 μm), and the gap between the downstream lip land 18b and the web WW. _GL was set to 60 μm. Further, the gap G _B between the gap G _S, and the back plate 40a and the web WW between the side plate 40b and the web WW of the decompression chamber 40 were both 200 [mu] m.

Film Preparation Method An 80 μm-thick triacetyl cellulose film (TD80U: trade name, manufactured by Fuji Photo Film Co., Ltd.) was unwound in a roll form, and the coating solution for antiglare hard coat layer was dried as shown in Table 1. Coating was performed at a coating speed of 25 m / min using the die coater so as to obtain a film thickness. The degree of vacuum in the vacuum chamber was 0.8 kPa. After solvent drying at 110 ° C. for 10 seconds, 50 ° C. for 20 seconds, and under nitrogen purge (oxygen concentration of 200 ppm or less), UV irradiation (half cure) is performed so that the integrated light amount becomes 55 mJ, photocuring, An antiglare layer was formed and wound up.

Coating method A for low refractive index layer
The triacetyl cellulose film provided with the antiglare hard coat layer was unwound again, and the low refractive index layer coating solution was applied at a coating speed of 25 m / min using the die coater. The gap GL between the downstream lip land 18b and the web W was changed to 50 μm, and the degree of vacuum in the vacuum chamber was 0.8 kPa. After drying at 120 ° C. for 70 seconds and further drying at 110 ° C. for 10 minutes and thermosetting, UV irradiation (full cure) is performed under a nitrogen purge (oxygen concentration of 100 ppm or less) so that the integrated light amount becomes 120 mJ. Then, it was photocured to form an antireflection film coated with a low refractive index layer and wound up.
In the above, the coating and drying steps are performed in an air atmosphere with an air cleanliness of 30 particles / (cubic meter) or less as particles of 0.5 μm or more, and the cleanliness described in JP-A-10-309553 is just before the coating. High air was blown at a high speed to separate the deposits from the film surface, and coating was performed while removing dust by a method of sucking with a suction port close to the film. The charged voltage of the base before dust removal was 200 V or less. Said application | coating was performed in each process of sending-out-dust removal-application-dry- (UV or heat) hardening-winding up for every layer.

Low refractive index layer coating method B
An antiglare layer was formed by the same method as the coating method A for the low refractive index layer except that the overbite length was changed to 0 μm.

Coating method C of low refractive index layer
An antiglare layer was prepared by the same method as the coating method A for the low refractive index layer except that the coating was performed by bar coating.

(Saponification treatment of antireflection film)
The antireflection film was subjected to the following treatment.
A 1.5 mol / l aqueous sodium hydroxide solution was prepared and kept at 55 ° C. A 0.01 mol / l 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, saponified antireflection films (present invention samples 1 to 12 and comparative samples 1 to 4) were produced.

(Evaluation of antireflection film)
About these obtained antireflection film samples, the following items were evaluated. The results are shown in Table 1.

(1) Average reflectance 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. For the result, an integrating sphere average reflectance in a wavelength region of 450 to 650 nm was used.

(2) Steel wool scratch resistance evaluation A rubbing test was performed using a rubbing tester under the following conditions.
Evaluation environmental conditions: 25 ° C., 60% RH.
Rub material: Steel wool (manufactured by Nippon Steel Wool Co., Ltd., Gelade No. 0000) was wound around the rubbing tip (1 cm × 1 cm) of a tester that was in contact with the sample, and the band was fixed so as not to move.
Moving distance (one way): 13 cm, rubbing speed: 13 cm / sec, load: 500 g / cm ² , tip contact area: 1 cm × 1 cm, rubbing frequency: 10 reciprocations.
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.
○: No scratches are visible, or slightly weak scratches are observed when viewed very carefully.
○ △: Weak scratches are visible.
Δ: Moderate scratches are visible.
X: There are scratches that can be seen at first glance.

(3) Contact angle of water After adjusting the humidity at 25 ° C. and 60% RH, the contact angle of water was measured using a contact angle measuring device CA-DT • A manufactured by Kyowa Interface Science. The column after addition of Table 1 and Table 2 is a value obtained by measuring the contact angle of water with respect to a sample prepared in the same manner except that the viscosity modifier described in the table is not added.

(4) Viscosity The viscosity was measured with a vibration viscometer (CJV-5000, manufactured by A & D Co., Ltd.) at a liquid temperature of 25 ° C. ± 1 °.
(5) Thixotropic property The ratio of the viscosity at the shear rate of 0.1 (1 / s) to the viscosity at the shear rate of 1000 (1 / s) of the coating composition when the addition amount of the viscosity modifier is 1% by mass is the thixotropy. Used for gender scale. The viscosity at each shear rate was measured with Rotovisco.
(6) Dispersibility When an inorganic layered compound was used as the viscosity modifier, US was applied for 10 minutes in the solvent used in the coating composition and dispersed, and then the particle size was measured with a Coulter counter.
(7) Surface uniformity (visual)
The surface opposite to the coated surface was painted black, and a fluorescent lamp was irradiated from the surface side, and surface irregularities such as coating unevenness and drying unevenness were evaluated by reflection visual inspection.
×: Strong unevenness is visible △: Unevenness is visible ○: Well-observed unevenness is visible ◎: No unevenness (8) Surface shape (spotted, cloudy)
The surface opposite to the coated surface was painted black, irradiated with a fluorescent lamp from the surface side, and the occurrence of foreign matter was evaluated by reflection visual inspection.
×: Conspicuous and cloudy are conspicuous △: Conspicuous and cloudy when viewed closely ○: Conspicuous and opaque are not conspicuous (8) Planar (optical microscope)
The surface state was observed with an optical microscope at a magnification of × 400, and the change in the surface state before and after the addition of the viscosity modifier was evaluated.
×: Significant change (phase separation)
(Triangle | delta): Although it has changed a little, the film | membrane is formed uniformly.
Y: No change

According to the present invention, an antireflection film having excellent surface uniformity and high productivity can be obtained.
Note that the haze value of the sample in which the coating solution for low refractive index of the present invention was applied in a single layer to a thickness of 100 nm was 1% or less.

In the inventive samples 1 to 11, when the diluent solvent used in the anti-glare hard coat layer coating solution A is a solvent composition of toluene / cyclohexanone = 85/15 and toluene / cyclohexanone = 70/30 instead of toluene, the ratio of cyclohexanone As the thickness increased, the interfacial adhesion of the support / antiglare hard coat layer was strengthened, and the scratch resistance was improved.
Moreover, in this invention samples 1-12, when the sol liquid b was used instead of the sol liquid a of the organosilane used for the low refractive index layer coating liquid, the temporal stability of the coating liquid was improved, and continuous coating was not performed. The aptitude increased.
Moreover, in this invention samples 1-12, instead of the heat-crosslinkable fluorine-containing polymer used for the coating solution for the low refractive index layer, a heat-crosslinkable fluorine-containing polymer having a refractive index of 1.44 (JTA113, solid content concentration 6%) , Manufactured by JSR Co., Ltd.), the scratch resistance was remarkably improved.

  When the coating speed of the low refractive index layer was set to 40 m / min for the inventive samples 1, 4, and 9 to 12, only the inventive sample 1 that did not use the thixotropy imparting agent had no coating on the base. .

[Example 2: Preparation and evaluation of inventive samples 13 to 14 and comparative samples 5 to 6 of an antireflection film]
(Preparation of coating liquid C for hard coat layer)
To 315.0 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku Co., Ltd.), methyl ethyl ketone dispersion of silica fine particles (MEK-ST, solid content concentration 30 mass%, Nissan Chemical ( 450.0 g, 15.0 g of methyl ethyl ketone, 220.0 g of cyclohexanone, and 16.0 g of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Specialty Chemicals) were 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 hard coat layer.

(Preparation of titanium dioxide fine particle dispersion)
As titanium dioxide fine particles, titanium dioxide fine particles (MPT-129C, manufactured by Ishihara Sangyo Co., Ltd.) containing cobalt and surface-treated with aluminum hydroxide and zirconium hydroxide were used.
The following dispersant (38.6 g) and cyclohexanone (704.3 g) were added to 257.1 g of the particles and dispersed by dynomill to prepare a titanium dioxide dispersion having a mass average diameter of 70 nm.
Dispersant

(Preparation of coating liquid E for medium refractive index layer)
To 88.9 g of the above titanium dioxide dispersion, 58.4 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA), 3.1 g of a photopolymerization initiator (Irgacure 907), a photosensitizer (Kayacure DETX) 1.1 g of Nippon Kayaku Co., Ltd.), 482.4 g of methyl ethyl ketone and 1869.8 g of cyclohexanone were added and stirred. After sufficiently stirring, the mixture was filtered through a polypropylene filter having a pore size of 0.4 μm to prepare a coating solution E for medium refractive index layer.

(Preparation of coating liquid F for high refractive index layer)
To 56.8 g of the above titanium dioxide dispersion, 47.9 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku Co., Ltd.), photopolymerization initiator (Irgacure 907, Ciba Specialty) Chemicals 4.0), photosensitizer (Kayacure-DETX, Nippon Kayaku Co., Ltd.) 1.3 g, methyl ethyl ketone 455.8 g, and cyclohexanone 1427.8 g were added and stirred. After sufficiently stirring, the mixture was filtered through a polypropylene filter having a pore size of 0.4 μm to prepare a coating solution F for a high refractive index layer.

(Preparation of antireflective film samples 13 to 14 and comparative samples 5 to 6)
On the triacetyl cellulose film (TD80UF, manufactured by Fuji Photo Film Co., Ltd.) having a film thickness of 80 μm, the hard coat layer coating solution was applied using the same die coater as in the antiglare hard coat application of Example 1. After drying at 100 ° C., an irradiance of 400 mW / cm using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) of 160 W / cm while purging with nitrogen so that the oxygen concentration becomes 1.0 vol% or less. ^{2. The} coating layer was cured by irradiating ultraviolet rays with an irradiation amount of 300 mJ / cm ² to form a hard coat layer having a thickness of 3.5 μm.
On the hard coat layer, the medium refractive index layer coating solution was applied using the same die coater as used in forming the low refractive index layer of Example 1. After drying at 100 ° C., an illuminance of 550 mW / cm using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) of 240 W / cm while purging with nitrogen so that the atmosphere has an oxygen concentration of 1.0% by volume or less. ^2. An ultraviolet ray with an irradiation amount of 600 mJ / cm ² was irradiated to cure the coating layer to form a medium refractive index layer (refractive index 1.65, film thickness 67 nm).

On the middle refractive index layer, the coating solution for the high refractive index layer was applied using the same die coater as in the formation of the low refractive index layer in Example 1. After drying at 100 ° C., an illuminance of 550 mW / cm using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) of 240 W / cm while purging with nitrogen so that the atmosphere has an oxygen concentration of 1.0% by volume or less. ^2. Irradiation with an irradiation amount of 600 mJ / cm ² was applied to cure the coating layer to form a high refractive index layer (refractive index 1.93, film thickness 107 nm).

  On the high refractive index layer, the coating solution for the low refractive index layer was applied using the same die coater as in the formation of the low refractive index layer in Example 1, and drying and curing were performed under the same conditions.

(Evaluation of antireflection film)
The obtained film sample was evaluated in the same manner as in Example 1. The results are shown in Table 2.

From the results shown in Tables 1 and 2, the following is clear.
In the antireflection film of the present invention, the viscosity modifier increases the viscosity of the liquid and improves the surface uniformity without deteriorating the performance of the coating.
In particular, when a viscosity modifier having thixotropy is used, the coating can be applied at a higher speed and a uniform surface can be obtained.
In addition, an antireflection film having excellent surface uniformity and high productivity can be obtained with high productivity.

[Example 3]
The PVA film was immersed in an aqueous solution of 2.0 g / l iodine and 4.0 g / l potassium iodide at 25 ° C. for 240 seconds, and further immersed in an aqueous solution of boric acid 10 g / l at 25 ° C. for 60 seconds. It introduced into the tenter drawing machine of the form of FIG. 2 described in 2002-86554, it extended | stretched 5.3 time, the tenter was bent like FIG. 2 with respect to the extending | stretching direction, and the width | variety was kept constant hereafter. After drying in an atmosphere of 80 ° C., it was detached from the tenter. The difference in transport speed between the left and right tenter clips was less than 0.05%, and the angle between the center line of the introduced film and the center line of the film sent to the next process was 46 °. Here, the difference between the left and right tenter clip positions | L1-L2 | was 0.7 m, the width W of the support was 0.7 m, and the relationship was | L1-L2 | = W. The substantial stretching direction Ax-Cx at the tenter outlet was inclined by 45 ° with respect to the center line 22 of the film sent to the next process. Wrinkles and film deformation at the tenter exit were not observed.
Furthermore, it was bonded to Fuji Photo Film Co., Ltd. Fujitac (cellulose triacetate, retardation value 3.0 nm), which was saponified with an aqueous solution of PVA (Pura-117H, Kuraray Co., Ltd.) 3%, and further 80 ° C. And dried to obtain a polarizing plate having an effective width of 650 mm. The absorption axis direction of the obtained polarizing plate was inclined 45 ° with respect to the longitudinal direction. The polarizing plate had a transmittance at 550 nm of 43.7% and a polarization degree of 99.97%. Further, when the substrate was cut into a size of 310 × 233 mm, a polarizing plate having a 45 ° absorption axis inclined with respect to the side with an area efficiency of 91.5% was obtained.
Next, the respective films of the inventive samples of Examples 1 and 2 (saponified) were bonded to the polarizing plate to produce a polarizing plate with an antireflection function. Using this polarizing plate, a liquid crystal display device having an antireflection layer disposed on the outermost layer was produced. As a result, there was no reflection of external light, and an excellent contrast was obtained. It had visibility.

[Example 4]
An 80 μm-thick triacetylcellulose film (TAC-TD80U, manufactured by Fuji Photo Film Co., Ltd.), immersed in a 1.5 mol / L, 55 ° C. NaOH aqueous solution for 2 minutes, neutralized and washed with water, and Examples Polarizers were prepared by adhering and protecting both sides of a polarizer prepared by adsorbing iodine to polyvinyl alcohol on the backside saponified triacetylcellulose film of each of the inventive samples 1 and 2 and stretching. The thus-prepared polarizing plate is a liquid crystal display device of a notebook PC equipped with a transmission type TN liquid crystal display device (Sumitomo 3M Co., Ltd., which is a polarization separation film having a polarization selection layer) so that the antireflection film side is the outermost surface. When the polarizing plate on the viewing side of D-BEF made of D-BEF (having between the backlight and the liquid crystal cell) was replaced, a display device with extremely high display quality was obtained with very little background reflection.

[Example 5]
Viewing angle as a protective film on the liquid crystal cell side of the polarizing plate on the viewing side of the transmission type TN liquid crystal cell to which the inventive sample of Examples 1 and 2 was attached, and a protective film on the liquid crystal cell side of the polarizing plate on the backlight side When an enlarged film (Wideview Film Super Ace, manufactured by Fuji Photo Film Co., Ltd.) is used, it has excellent contrast in a bright room, very wide viewing angles in the top, bottom, left and right, extremely excellent visibility, and display quality. A high liquid crystal display device was obtained.
In addition, the inventive sample 12 (light diffusion layer coating solution B) has a scattered light intensity of 30 ° with respect to an emission angle of 0 ° of 0.06%. Up, the yellowness in the left-right direction was improved, and it was a very good liquid crystal display device. For comparison, the film produced in the same manner as Sample 12 of the present invention except that the crosslinked PMMA particles and silica particles were removed from the coating solution B for light diffusion layer, the scattered light intensity at 30 ° with respect to an emission angle of 0 ° was substantially 0. %, The downward viewing angle was increased, and no yellowish improvement effect was obtained.

[Example 6]
When the inventive samples of Examples 1 and 2 were bonded to a glass plate on the surface of an organic EL display device via an adhesive, reflection on the glass surface was suppressed, and a display device with high visibility was obtained. .

[Example 7]
A polarizing plate with a single-sided antireflection film was prepared using the samples of Examples 1 and 2, and a λ / 4 plate was bonded to the opposite surface of the polarizing plate on the side having the antireflection film, and the surface of the organic EL display device When attached to the glass plate, surface reflection and reflection from the inside of the surface glass were cut, and a display with extremely high visibility was obtained.

(A) is a cross-sectional schematic diagram which shows the layer structure of an anti-glare antireflection film. (B) is a cross-sectional schematic diagram which shows the layer structure of the antireflection film excellent in antireflection performance. It is a structural example of the apparatus which performs application | coating of each structural layer of an optical functional film continuously. It is a schematic sectional drawing which shows the coater using a slot die. (A) is a schematic sectional drawing which shows the slot die of this invention. (B) is a schematic sectional view showing a conventional slot die. It is a perspective view which shows the slot die and its peripheral part of an application | coating process. It is a schematic sectional drawing which shows the pressure reduction chamber and web which adjoin. It is a schematic sectional drawing which shows the pressure reduction chamber and web which adjoin.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Antireflection film 2 Transparent support 3 Hard coat layer 4 Anti-glare hard coat layer 5 Low refractive index layer 6 Fine particle 7 Medium refractive index layer 8 High refractive index layer 10 Coater 11 Backup roll 13 Slot die 14a Bead 14b Coating film 15 Pocket 16 Slot 16a Opening 17 Tip lip 18 Flat part (land)
18a upstream lip land 18b downstream lip land 30 conventional slot die 31a upstream lip land 31b downstream lip land 32 pocket 33 slot 40 decompression chamber 40a back plate 40b side plate 40c screw
100, 200, 300, 400 Film forming unit
101, 201, 301, 401 Step of applying coating solution 102, 202, 302, 402 Step of drying coating solution
103, 203, 303, 403 Step of curing coating liquid 110 Continuous feeding step of roll-shaped support member 120 Continuous winding step of support member W web
I _UP upstream lipland length
I _LO downstream lip land length G _L Gap between downstream lip land and web G _S Gap between side plate and web G _B Gap between back plate and web

Claims (30)

(A) A compound polymerizable by heat or active energy ray irradiation, (B) a viscosity modifier and (C) a solvent, having a refractive index after curing of 1.50 or less, and forming a film having a thickness of 100 nm A coating composition capable of forming a transparent film having a haze of 2% or less. (D) The coating composition according to claim 1, comprising inorganic fine particles having an average particle diameter of 100 nm or less.   The coating composition according to claim 2, wherein the inorganic fine particles are hollow particles.   Solid content concentration is 10 mass% or less, The coating composition in any one of Claims 1-3 characterized by the above-mentioned.   The coating composition according to any one of claims 1 to 4, wherein the content of the (B) viscosity modifier with respect to the total solid content is 30% by mass or less. (B) Viscosity when no viscosity modifier is added is 5 mPa · s (cp) or less, and the viscosity measured with a vibration viscometer is less than 5% by mass with respect to the total amount of the coating solution. The coating composition according to claim 1, wherein the coating composition increases 1.3 times or more in comparison.   The coating composition according to any one of claims 1 to 6, wherein the refractive index of the coated film after curing does not increase by 0.05 or more due to the addition of (B) viscosity modifier.   The water contact angle of the transparent film after curing is 90 degrees or more, and (B) the contact angle reduction of water due to the addition of the viscosity modifier is 5 degrees or less. Coating composition. (B) The coating composition according to any one of claims 1 to 8, wherein the viscosity modifier has thixotropic properties. (A) The coating composition according to any one of claims 1 to 9, wherein the compound polymerizable by irradiation with heat or active energy rays is a fluorine-containing compound. (C) The solvent contains a ketone solvent, The coating composition according to any one of claims 1 to 10. (B) The coating composition according to any one of claims 1 to 11, wherein an inorganic layered compound subjected to an organic treatment is dispersed as a viscosity modifier.   The coating composition according to claim 12, wherein the inorganic layered compound is synthetic smectite. The coating composition according to claim 12 or 13, wherein the organic treatment agent is represented by the following general formula (1).
General formula (1)
(N (R _a ) _4-n (R _b ) _n ) ⁺ A ⁻
In the formula, Ra is represented by (CH ₂ ) _m H or (CH ₂ ) _m R _c H or (CH ₂ Rc) _m H, m is an integer of 2 or more, and R _c may have any structure or may be absent. , R _b represents CH ₃ , and n represents 0 or an integer of 1 to 3. A ⁻ represents Cl ⁻ or Br ⁻ .   The coating composition according to any one of claims 12 to 14, wherein an average particle size after dispersion of the inorganic layered compound is 200 nm or less. (B) The coating composition according to any one of claims 1 to 11, wherein the viscosity modifier is a polymer having no polymerizable group having a molecular weight of 100,000 or more.   A layer having a film thickness of 200 nm or less obtained by applying the coating composition according to any one of claims 1 to 16 on a transparent substrate, removing the solvent by drying, and curing by heat or active energy ray irradiation. An optical functional layer characterized by being.   The optical functional layer according to claim 17, comprising 30% by mass or less of the viscosity modifier defined in any one of claims 12 to 16.   The optical function layer according to claim 17 or 18, wherein a refractive index is 1.45 or less.   An antireflection film, wherein a hard coat layer containing resin beads is formed on a transparent support, and the optical functional layer according to any one of claims 17 to 19 is formed thereon.   The hard coat layer containing resin beads is formed by dispersing at least one kind of translucent particles having an average particle diameter of 0.5 to 5 μm in the translucent resin, and the translucent particles and the translucent resin 21. The reflection according to claim 20, wherein the difference in refractive index is 0.02 to 0.2, and the translucent particles are contained in an amount of 3 to 30% by mass of the total solid content of the light scattering layer. Prevention film.   The antireflective film having two or more thin film layers having different refractive indexes of 200 nm or less on the transparent support, wherein the low refractive index layer located on one surface of the transparent support is defined in claims 17-19. The optical functional layer according to any one of the above, having at least one high refractive index layer having a higher refractive index than that of the low refractive index layer, between the transparent support and the low refractive index layer. An antireflective film characterized in that both the refractive index layer and the high refractive index layer contain inorganic fine particles, and the average value of the specular reflectance at 5 ° incidence at a wavelength of 450 nm to 650 nm is 1% or less. The color of the specularly reflected light with respect to the incident light of 5 degrees of the CIE standard light source D65 in the wavelength region of 380 nm to 780 nm indicates that the a ^* and b ^* values of the CIE1976L ^* a ^* b ^* color space are −8 ≦ a ^* ≦ 8, And it exists in the range of -10 <= b ^* <= 10, The antireflection film in any one of Claims 20-22 characterized by the above-mentioned.   The land of the tip lip of the slot die is brought close to the surface of the web supported continuously by the backup roll, and the coating composition is applied from the slot of the tip lip, followed by solvent drying and ionizing radiation as necessary. Alternatively, the optical functional layer according to any one of claims 17 to 19 is formed by a method of curing with heat.   When a slot die having a land length in the web traveling direction of the tip lip on the web traveling direction side of the slot die is set to 30 μm or more and 100 μm or less and the slot die is set at a coating position, Is applied using a coating apparatus installed such that the gap between the tip lip on the opposite side and the web is larger by 30 μm or more and 120 μm or less than the gap between the tip lip on the web traveling direction side and the web. The method for producing an optical functional layer according to claim 24.   The method for producing an optical functional layer according to claim 24 or 25, wherein a web conveyance speed during coating is 20 m / min or more.   It is the polarizing plate which bonded together the surface protection film of 2 sheets on the surface and back surface of a polarizer, The antireflection film in any one of Claims 20-23 was used for the surface protection film of at least one side, It is characterized by the above-mentioned. Polarizing plate.   The surface protection film itself located on the surface opposite to the surface on which the antireflection film as the surface protection film of the polarizing plate is bonded, and the film located between the surface protection film and the polarizer The polarizing plate according to claim 27, wherein at least one of the films is an optical compensation film.   An image display device comprising at least one of the antireflection film according to any one of claims 20 to 23 or the polarizing plate according to claim 27 or 28.   A TN, STN, VA, IPS, or OCB mode transmissive, reflective, or transflective liquid crystal display device having at least one polarizing plate according to claim 27 or 28.

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