JP2008105191A - Optical film, antireflection film, polarizing plate, display device and manufacturing method of optical film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical film reduced in curling while having strong film strength and exhibiting a necessary optical performance, an antireflection film using it, a polarizing plate, a display device and a manufacturing method of the optical film. <P>SOLUTION: The optical film has at least a hard coat layer on a transparent support and the hard coat layer is formed of a composition in which at least one layer contains a bifunctional (meth)acrylate compound (A) having a molecular weight of 210-500 and having an alicyclic ring, an aromatic ring and a heterocyclic structure, a polyfunctional acrylate compound (B) having at least three (meth)acryloyl group, and a photopolymerization initiator (C). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical film, an antireflection film, a polarizing plate, a display device, and a method for producing an optical film.

  In recent years, liquid crystal display devices (LCD) have increased in screen size, and for example, liquid crystal display devices having an optical film such as an antireflection film or a light diffusion sheet are increasing. For example, the antireflection film is used in various image display devices such as a liquid crystal display device (LCD), a plasma display panel (PDP), an electroluminescence display (ELD), and a cathode ray tube display device (CRT). Is disposed on the surface of the display in order to prevent a decrease in contrast due to the reflection of the image. The light diffusion sheet is used on the backlight side of the liquid crystal display device.

The optical film is usually produced by laminating a light diffusing (hard coat) layer or a high refractive index layer and a low refractive index layer on a transparent support. The installation method is based on chemical vapor deposition (CVD) method or physical vapor deposition (PVD) method, particularly vacuum deposition method or sputtering method, which is a kind of physical vapor deposition method, or coating method with excellent productivity. Often done.
Since an optical film is used on the outermost surface of a display, various film strengths such as scratch resistance against fine scratches and film hardness that can withstand pressure when written with a writing instrument are required. On the other hand, in order to make the surface of the display film thinner, it is also required to make the support thinner.
When the film strength is imparted or the support is thinned, the curl becomes larger, making it difficult to handle and manufacture the surface film, causing cracks (brittleness) in the film during handling, There has been a problem that the peeling phenomenon occurs after alignment. In order to improve this problem, an invention using a modified acrylate compound (Patent Document 1) and a urethane acrylate compound (Patent Document 2), an invention using a mixture of acrylate compounds having different properties (Patent Documents 3 and 4) ) Has been.
However, in the above invention, although the curl improvement effect, the improvement of brittleness and the like are recognized, the film surface hardness is lowered, and it is difficult to achieve both the surface hardness and these properties, which is sufficient for the optical film. Development of material technology having strength has been desired.

JP 2005-181996 A JP 2005-288787 A JP 2005-103979 A JP 2003-335983 A

  As a result of diligent research on a photocured composition that can reduce curl and improve brittleness while maintaining the surface hardness of the film, the present inventor has obtained a bifunctional acrylate compound having a specific structure in a trifunctional or higher acrylate compound. It has been found that mixing is possible, and it is found that an optical film having stable optical performance can be prepared by combining with constituent elements of the antireflection effect.

  An object of the present invention is to stably provide an optical film having a strong film strength (surface hardness, flexibility) and a small curl and stably exhibiting necessary optical performance. Furthermore, it is providing the polarizing plate and display apparatus using such an optical film.

  In the present invention, the hard coat layer is (A) a bifunctional acrylate compound having a molecular weight in the range of 210 to 500 and having at least one of an alicyclic ring, an aromatic ring, and a heterocyclic structure in the molecule, (B) 3 An optical film, an antireflection film, or an optical film comprising a polyfunctional acrylate compound having at least one (meth) acryloyl group and a layer formed from a composition containing (C) a photopolymerization initiator. The object is achieved by the present invention by providing a manufacturing method, a polarizing plate, and an image display device. In more detail, it consists of the following invention composition.

(1) An optical film having at least one hard coat layer on a transparent support, wherein at least one layer of the hard coat layer is
(A) a bifunctional (meth) acrylate compound having a molecular weight in the range of 210 to 500 and having at least one of an alicyclic ring, an aromatic ring and a heterocyclic structure in the molecule;
(B) a polyfunctional acrylate compound having three or more (meth) acryloyl groups,
(C) The optical film characterized by being a layer formed from the composition containing a photoinitiator.
(2) The optical film as described in (1), wherein the hard coat layer is a light diffusing hard coat layer containing translucent particles.
(3) The hard coat layer is composed of at least two hard coat layers of a light diffusing hard coat layer containing translucent particles and a transparent hard coat layer not containing translucent particles, and the transparency The optical film as described in (1) or (2), wherein the hard coat layer is a layer formed from a composition containing the compounds (A), (B) and (C).
(4) The thickness of the light diffusing hard coat layer is 0.03 to 0.20 times the thickness of the transparent support, and the average particle size of the light transmissive particles is the light diffusing hard coat. The optical film as described in (2) or (3), wherein the thickness is 0.2 to 0.8 times the thickness of the layer.
(5) The optical film according to any one of (1) to (4) has a layer having a refractive index lower than that of the transparent support on the hard coat layer or the light diffusing hard coat layer. Antireflection film.
(6) A polarizing plate having a pair of protective films and a polarizing film between the pair of protective films, wherein at least one of the protective films is the optical film according to any one of (1) to (4) Or a polarizing plate, which is the antireflection film according to (5).
(7) A display device having the optical film according to any one of (1) to (4), the antireflection film according to (5), or the polarizing plate according to (6), wherein the optical film, A display device, wherein an antireflection film or a hard coat layer, a light diffusible hard coat layer, or a low refractive index layer of a polarizing plate is disposed on the viewing side.
(8) A method for producing an optical film having at least one hard coat layer or at least one light diffusing hard coat layer on a transparent support, wherein the at least one hard coat layer, or at least One light diffusing hard coat layer
(A) a bifunctional (meth) acrylate compound having a molecular weight in the range of 210 to 500 and having at least one of an alicyclic ring, an aromatic ring and a heterocyclic structure in the molecule;
(B) a polyfunctional acrylate compound having three or more (meth) acryloyl groups,
(C) A method for producing an optical film, wherein a coating liquid containing a photopolymerization initiator and having a viscosity in the range of 10 to 200 mPa · s is applied by a die coating method and cured.

  The optical film of the present invention has a strong film strength, a small curl, and an excellent required optical performance. Moreover, the optical film which has such a performance can be manufactured stably. Furthermore, the optical film of the present invention, the display device provided with the antireflection film, and the display device provided with the polarizing film using the optical film of the present invention and the antireflection film have little reflection of external light and background reflection. It has extremely high visibility, little display unevenness, and high display quality.

  In the present invention, a hard coat layer containing translucent particles on the order of several μm that changes light scattering properties or antiglare properties is also referred to as a light diffusing hard coat layer, and a hard coat layer that does not contain translucent particles Also referred to as a transparent hard coat layer.

  The optical film of the present invention has at least one hard coat layer on a transparent support. The hard coat layer may or may not contain translucent particles, may be a hard coat layer having light diffusibility (including antiglare properties), or light diffusibility. It may be a hard coat layer not having any. Moreover, one layer may be sufficient and it may be comprised by multiple layers, for example, 2-4 layers, and the combination of the light diffusible hard-coat layer and the transparent hard-coat layer which does not have light diffusibility may be sufficient. The refractive index (measured by Abbe refractometer, manufactured by Atago Co., Ltd.) of the material other than the translucent particles of the hard coat layer is preferably in the range of 1.45 to 2.00.

  The laminated arrangement of the transparent hard coat layer and the light diffusing hard coat layer is not particularly limited. The transparent hard coat layer and the light diffusing hard coat layer may be arranged in this order from the support side, or the opposite arrangement may be employed.

  In the present invention, the hard coat layer is composed of at least two hard coat layers of a light diffusible hard coat layer containing translucent particles and a transparent hard coat layer not containing translucent particles, and the transparency An optical film in which the hard coat layer is a layer formed from a composition containing the compounds (A), (B), and (C) is preferable, and the transparent hard coat layer and the light diffusing hard coat layer are More preferably, the layer is formed from a composition containing the compounds (A), (B), and (C).

  The optical film of the present invention may be provided with a functional layer other than the hard coat layer. Examples of these layers include an antistatic layer, a high refractive index layer, a low refractive index layer, and an antifouling layer. Can be mentioned. The antistatic layer preferably contains conductive inorganic fine particles. The high refractive index layer preferably has a refractive index in the range of 1.50 to 2.00. The low refractive index layer preferably has a refractive index in the range of 1.20 to 1.48, and is preferably coated adjacent to the outside of the hard coat layer or the high refractive index layer. Also good. Further, an antifouling layer may be further provided on the low refractive index layer.

Further, the low refractive index layer preferably satisfies the following formula (I) from the viewpoint of reducing the reflectance.
Formula (I)
(Mλ / 4) × 0.7 <n ₁ d ₁ <(mλ / 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 (I) means that m (positive odd number, usually 1) which satisfy | fills numerical formula (I) exists in the said wavelength range.

The optical film of the present invention preferably has internal scattering properties. The internal scattering property is generally represented by internal haze, and the internal haze is obtained by removing the surface haze from the total haze that is usually measured. When the antireflection film of the present invention is incorporated in the outermost surface of the display device, the internal scattering property is an optical unevenness (for example, luminance unevenness of the light source or chromaticity of the color filter) that each of the other components of the display device has. Unevenness and the like) can be reduced. However, if the internal haze becomes too high, the contrast is lowered. Therefore, the internal haze is preferably 1 to 60%, more preferably 1 to 50%, and particularly preferably 1 to 40%.
Further, the surface haze of the optical film of the present invention is preferably 0 to 10% for improving the darkening feeling, more preferably 0.1 to 7%, and more preferably 0.3 to 5%. The surface haze according to the present invention is obtained by obtaining all haze and internal haze separately, and subtracting the internal haze from the total haze by calculation.
The transmitted image clarity of the optical film of the present invention is preferably from 30 to 80%, more preferably from 30 to 70% from the viewpoint of both antiglare properties and a feeling of darkening. In the present invention, the coating composition is sometimes referred to as a coating solution, but both are synonymous.

[Hard coat layer]
The hard coat layer according to the present invention is a layer that affects physical performance and optical performance, and the coating composition mainly contains a monomer for a matrix-forming binder, an oligomer, polymers, and an organic solvent. Moreover, translucent particle | grains are contained depending on the case.
More specifically, the coating composition for forming the hard coat layer has (A) a molecular weight in the range of 210 to 500 for the main matrix-forming binder, and at least any of an alicyclic ring, an aromatic ring, and a heterocyclic structure in the molecule. Containing a bifunctional (meth) acrylate compound having (B), a polyfunctional acrylate compound having 3 or more (meth) acryloyl groups, (C) a photopolymerization initiator, and if necessary, the specific particle size ratio Translucent particles having an additive, an additive for increasing the film hardness, an inorganic fine filler for curling reduction and refractive index adjustment, a coating aid, and the like.

In the case of a light diffusing hard coat layer (also referred to as a light diffusing layer), the thickness of the hard coat layer is preferably 0.03 to 0.20 with respect to the thickness of the transparent support, and 0.05 to 0.17. Is more preferable, and 0.07 to 0.15 is even more preferable. Therefore, if the support thickness is 80 μm, the thickness of the light diffusion layer is preferably 2.4 μm to 16 μm, and if the support thickness is 40 μm, 1.2 μm to 8 μm is preferable. When the thickness is within this range, the film hardness is excellent, there are no defects such as curl, haze value, and glare, and the adjustment of anti-glare property and darkness is easy.
Moreover, in the case of a transparent hard-coat layer, 0.02-0.40 are preferable with respect to a transparent support body thickness, and 0.04-0.30 are more preferable.

[binder]
The binder in the present invention refers to a film component excluding translucent particles, and includes a cured product of polymerizable compounds, a polymer compound described later, an organosilicon compound, a surfactant, and the like.
In the present invention, the main component of the binder is (A) a molecular weight in the range of 210 to 500 due to radicals generated from (C) the photopolymerization initiator by ionizing radiation or the like, and the molecule has an alicyclic ring, aromatic ring, A bifunctional (meth) acrylate compound having at least one of a ring structure and (B) a polyfunctional acrylate compound having three or more (meth) acryloyl groups are polymerized and crosslinked, and these are hard coat layers It is estimated that it becomes a determinant of physical properties such as surface hardness, brittleness, and properties such as curling.

  The bifunctional (meth) acrylate compound (A) is a (meth) acrylate compound having a molecular weight in the range of 210 to 500 and having at least one of an alicyclic ring, an aromatic ring and a heterocyclic structure in the molecule. . Specific examples of the alicyclic ring include a saturated or unsaturated ring having 5 to 20 carbon atoms such as a cyclopentane ring, a cyclohexane ring, a cyclohexene ring, a cycloheptadiene ring, and a norbornane ring. An aromatic ring having 6 to 20 carbon atoms such as a benzene ring, naphthalene ring, anthracene ring, diphenylmethane ring, triphenylmethane ring, as a heterocyclic ring, a furan ring, a thiophene ring, a pyrrole ring, a pyran ring, a thiopyran ring, a pyridine ring, Examples include heterocyclic rings such as sulfur atoms, nitrogen atoms and oxygen atoms having 5 to 20 elements such as thiazole ring, imidazole ring, pyrimidine ring, indole ring, quinoline ring, purine ring and isocyanuric ring. Among these rings, an alicyclic ring and a heterocyclic ring are preferable, and an alicyclic ring is more preferable. A bifunctional (meth) acrylate compound having a molecular weight in the range of 230 to 400 is preferably used. These bifunctional acrylate compounds affect the physical properties of the film (surface hardness, brittleness, curl) generated by photopolymerization and crosslinking by light irradiation. Assuming that a bifunctional acrylate compound having a molecular weight of more than 500 cannot obtain sufficient surface hardness because the crosslinking density is lowered, the bifunctional acrylate compound of the present invention is used as a regulator for the crosslinking structure and crosslinking density. Presumed to be working. Specific examples of the bifunctional (meth) acrylate compound include compounds represented by the following formula, but are not limited thereto.

(B) As a compound which has 3 or more (meth) acryloyl groups, the acrylate type compound which forms the hardened | cured material of high hardness widely used in this industry is mentioned. Examples of such compounds include esters of polyhydric alcohol and (meth) acrylic acid {for example, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO-modified tris. Methylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, EO-modified tri (meth) acrylate phosphate, trimethylolethane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol Tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol hexa (meth) acrylate DOO, 1,2,3-cyclohexane tetramethacrylate, polyurethane polyacrylate, polyester polyacrylate and caprolactone-modified tris (acryloyloxyethyl) isocyanurate.
As specific compounds of polyfunctional acrylate compounds having three or more (meth) acryloyl groups, KAYARAD DPHA, DPHA-2C, PET-30, TMPTA, and TPA-320 manufactured by Nippon Kayaku Co., Ltd. , TPA-330, RP-1040, T-1420, D-310, DPCA-20, DPCA-30, DPCA-60, GPO-303, V made by Osaka Organic Chemical Industry Co., Ltd. Examples include esterified products of polyols such as # 400 and V # 36095D and (meth) acrylic acid. Also, purple light UV-1400B, UV-1700B, UV-6300B, UV-7550B, UV-7600B, UV-7605B, UV-7610B, UV-7620EA, UV-7630B, UV-7630B, UV-7640B. UV-6630B, UV-7000B, UV-7510B, UV-7461TE, UV-3000B, UV-3200B, UV-3210EA, UV-3210EA, UV-3310EA, UV-3310B, UV-3500BA , UV-3520TL, UV-3700B, UV-6100B, UV-6640B, UV-2000B, UV-2010B, UV-2250EA, UV-2750B (manufactured by Nippon Synthetic Chemical Co., Ltd.), UL-503LN (manufactured by Kyoeisha Chemical Co., Ltd.), Unidic 17-80 17-813, V-4030, V-4000BA (Dainippon Ink Chemical Co., Ltd.), EB-1290K, EB-220, EB-5129, EB-1830, EB-4358 (Daicel UCB ( Ltd.), High Corp AU-2010, AU-2020 (manufactured by Tokushi Co., Ltd.), Aronix M-1960 (manufactured by Toagosei Co., Ltd.), Art Resin UN-3320HA, UN-3320HC, UN-3320HS, UN Trifunctional urethane acrylate compounds such as -904, HDP-4T, Aronix M-8100, M-8030, M-9050 (manufactured by Toagosei Co., Ltd., KBM-8307 (manufactured by Daicel Cytec Co., Ltd.)) The above polyester compounds and the like can also be suitably used.

  Furthermore, resins having three or more (meth) acryloyl groups, such as relatively low molecular weight polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins And oligomers or prepolymers such as polyfunctional compounds such as polyhydric alcohols.

(A) The content of the bifunctional (meth) acrylate compound having at least one of an alicyclic ring, an aromatic ring and a heterocyclic structure is preferably 5 to 70% by mass with respect to the total amount of the binder, and 10 to 50 More preferably, it is contained in an amount of 20% by mass, and more preferably 20-40% by mass.
(B) It is preferable to contain 30-95 mass% with respect to binder whole quantity, and, as for content of the polyfunctional (meth) acrylate compound more than trifunctional, it is more preferable to contain 40-90 mass%.
The ratio of (A) and (B) is preferably 5:95 to 70:30, more preferably 10:90 to 50:50, in terms of mass ratio.

The photopolymerization initiator used in the present invention is a compound that generates a radical capable of initiating a radical polymerization reaction upon irradiation with ionizing radiation. “Latest UV Curing Technology” (p.159, publisher; Kazuhiro Takashiro, published) (Technical Information Association, Inc., published in 1991), Ciba Specialty Chemicals catalog, JP-A-2001-139663, JP-A-5-83588, JP-A-5-83588, JP-A No. 1-304453, U.S. Pat. No. 3,479,185, JP-A-5-239015, JP-A-8-134404, JP-A-11-217518, JP-A-2002-116539, JP-A-2002-116539, etc. Various known photopolymerization initiators described in the above publication can be used.
Among them, a photoinitiator having a photosensitivity wavelength of 300 nm to 430 nm and having a high photoinitiating ability is preferably used because the photosensitivity wavelength matches with a light source such as a high-pressure mercury lamp or a metal halide lamp. From the viewpoint of coloring the film, those having a photosensitive wavelength of 300 nm to 380 nm are more preferable.

  These polymerization initiators are preferably used in correspondence with the compounds to be polymerized, and are preferably used in a range of 0.1 to 15 parts by mass in terms of the total amount of the polymerization initiator with respect to 100 parts by mass of the compound to be polymerized. The range of 1-10 mass parts is more preferable.

  Specific photopolymerization initiators are listed below, but are not limited thereto.

(Polymer compound)
The hard coat layer according to the present invention may contain a polymer compound. By adding a polymer compound, curing shrinkage can be reduced, and the viscosity adjustment of the coating solution related to the dispersion stability (cohesiveness) of the resin particles can be performed more preferentially. In addition, solidification during the drying process It is preferable because the agglomeration behavior of the resin particles can be changed by controlling the polarity of the product, and drying unevenness in the drying process can be reduced.

  The polymer compound has already formed a polymer when added to the coating solution. Examples of the polymer compound include cellulose esters (for example, cellulose triacetate, cellulose diacetate, cellulose propionate, cellulose acetate Pionate, cellulose acetate butyrate, cellulose nitrate, etc.), urethanes, polyesters, (meth) acrylic acid esters (for example, methyl methacrylate / (meth) methyl acrylate copolymer, methyl methacrylate / (meta ) Ethyl acrylate copolymer, methyl methacrylate / butyl (meth) acrylate copolymer, methyl methacrylate / styrene copolymer, methyl methacrylate / (meth) acrylic acid copolymer, polymethyl methacrylate, etc.) Resin such as polystyrene is preferred Used.

The polymer compound is preferably 10 to 60% by mass, more preferably 20 to 50%, based on the total binder contained in the layer containing the polymer compound, from the viewpoint of effect on curing shrinkage and the effect of increasing the viscosity of the coating solution. It is preferable to contain in the range of mass%.
The molecular weight of the polymer compound is preferably from 30,000 to 400,000 in terms of mass average, more preferably from 50,000 to 300,000, and even more preferably from 50,000 to 200,000.

  The refractive index of the binder is preferably 1.40 to 2.00, more preferably 1.45 to 1.90, still more preferably 1.48 to 1.85, and particularly preferably as the whole matrix. Is 1.51-1.80. The refractive index of the binder is a value measured by removing resin particles from the components of the hard coat layer.

  It is preferable to add the binder of a hard-coat layer in 20-95 mass% with respect to the solid content of the coating liquid of this layer.

The hard coat layer is preferably formed by applying the coating solution to a support, and then carrying out light irradiation, electron beam irradiation, heat treatment or the like to cause crosslinking or polymerization reaction. In the case of ultraviolet irradiation, ultraviolet rays emitted from light such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc, a metal halide lamp, etc. can be used.
Curing with ultraviolet rays is preferably performed by nitrogen purge or the like with an oxygen concentration of 4% by volume or less, more preferably 2% by volume or less, and most preferably 0.5% by volume or less. The temperature is preferably 20 ° C to 120 ° C, more preferably 30 ° C to 100 ° C. UV irradiation dose is preferably ^{20~1000mJ / cm 2, 30~600mJ / cm} 2 is more preferable.

  It is preferable for curling reduction that the hard coat layer of the present invention is used by appropriately mixing the compounds (A) and (B) at the above-mentioned preferable contents so that the shrinkage after curing is less than 10%. . The shrinkage mentioned here is represented by {(volume of binder before curing−volume of cured film after curing) / volume of binder before curing} × 100.

(Translucent particles)
The hard coat layer of the present invention can be used as a light diffusing hard coat layer by containing translucent particles.
The hard coat layer of the present invention preferably contains translucent particles having an average particle size of 0.2 to 0.8 times the thickness of the light diffusion layer. A more preferable average particle diameter is 0.3 to 0.8 times, more preferably 0.4 to 0.7 times the thickness of the light diffusion layer. When the average particle size is in the above range, the screen is excellent in blackening and has a moderate anti-glare property, and there is little roughness, and when viewing a high-definition display caused by surface irregularities called glare Can be reduced.

In order to effectively exhibit the light diffusing effect, it is preferable that the translucent particles have the above average particle diameter range and adjust the difference in refractive index with the binder described above. Specifically, the refractive index difference between the translucent particles and the binder is 0.02 or more, more preferably 0.03 or more and 0.25 or less, and particularly preferably 0.04 or more and 0.2 or less.
Further, the resin particles are preferably those in which the crosslinking agent is contained in an amount of 3 mol% or more with respect to all monomers before the particles are synthesized.
The amount of translucent particles added to the binder is preferably 2 to 40% by mass in the total solid content of the hard coat layer, and particularly preferably 4 to 25% by mass.
The coating amount of the light-transmitting particle is preferably ^{10mg / m 2 ~10000mg / m 2} , more preferably ^{50mg / m 2 ~4000mg / m 2} .

  Specific examples of the translucent particles according to the present invention include resin particles such as crosslinked polymethyl methacrylate particles, crosslinked methyl methacrylate-styrene copolymer particles, crosslinked polystyrene particles, and crosslinked methyl methacrylate-methyl acrylate. Preferred examples include polymer particles, crosslinked acrylate-styrene copolymer particles, melamine resin particles, benzoguanamine resin particles, and polycarbonate particles. Furthermore, so-called surface-modified particles in which a compound containing a fluorine atom, silicon atom, carboxyl group, hydroxyl group, amino group, sulfonic acid group, phosphoric acid group or the like is chemically bonded to the surface of these resin particles are also preferred. Of these, crosslinked styrene particles, crosslinked polymethyl methacrylate particles, crosslinked methyl methacrylate-styrene copolymer particles, and the like are preferable.

As the shape of the resin particles, either a true sphere or an indefinite shape can be used. The particle size distribution is preferably monodisperse particles because of the haze value, controllability of diffusibility, and uniformity of the coated surface. For example, when a particle having a particle size of 20% or more than the average particle size is defined as a coarse particle, the proportion of the coarse particle is preferably 1% or less of the total number of particles, more preferably 0.1% or less. Yes, more preferably 0.01% or less. Particles having such a particle size distribution are obtained by classification after a normal synthesis reaction, and particles having a more preferable distribution can be obtained by increasing the number of classifications or increasing the degree thereof.
Specific examples of the inorganic particles of the light transmissive particles, such as silica particles, hollow silica particles, alumina particles, TiO ₂ particles, Mg0 ₂ particles, Sr0 ₂ particles, BaO ₂ particles, SRS0 ₄ particles, SnO ₂ particles, ZnO ₂ Examples thereof include metal oxide particles such as particles. These are also preferably secondary particles or amorphous secondary particles in order to suppress particle settling during production.

  The particle size distribution of the particles is measured by a Coulter counter method, and the measured distribution is converted into a particle number distribution. The average particle size is calculated from the obtained particle distribution.

(Inorganic filler)
In the hard coat layer of the present invention, in order to increase the hardness of the layer, decrease the curing shrinkage, and further increase the refractive index, in addition to the above-mentioned translucent particles, an inorganic filler is used for adjusting the refractive index and adjusting the film strength. It can also be used for purposes.
The content of the inorganic filler is preferably 10% by mass or more, preferably 15% by mass to 80% by mass, more preferably 20% by mass to 70% by mass, based on the total solid content of the hard coat layer.
The inorganic filler is made of an oxide of at least one metal selected from titanium, zirconium, aluminum, indium, zinc, tin, and antimony, and the average particle size of primary particles is generally 0.2 μm or less, preferably It is also preferable to contain a fine inorganic filler of 0.1 μm or less, more preferably 0.06 μm or less.

  Conversely, in a light diffusion layer using resin particles having a high refractive index, it is also preferable to lower the refractive index of the binder in order to increase the difference in refractive index from the particles. For this purpose, silica fine particles, hollow silica fine particles and the like can be used as the inorganic filler. The preferred particle size is the same as that of the above-mentioned high refractive index fine inorganic filler.

Specific examples of these finely divided inorganic _{filler, TiO 2, ZrO 2, Al} 2 O 3, In 2 O 3, ZnO, SnO 2, Sb 2 O 3, ITO ( indium oxide doped with Sn), SiO ₂ or the like Can be mentioned. 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 fine inorganic filler does not scatter because the particle size is sufficiently shorter than the wavelength of light, and the dispersion in which the filler is dispersed in the binder polymer has the property of an optically uniform substance.

(Organic solvent)
The coating composition for forming the hard coat layer preferably contains at least one organic solvent.
Examples of the organic solvent include alcohol, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, isoamyl alcohol, 1-pentanol, n-hexanol, methyl amyl alcohol. In the ketone system, methyl isobutyl ketone, methyl ethyl ketone, diethyl ketone, acetone, cyclohexanone, diacetone alcohol, etc., in the ester system, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, isobutyl acetate, n-butyl acetate, Isoamyl acetate, n-amyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, methyl acetate, methyl lactate, ethyl lactate, ether, acetal, 1,4 dioxane, te In hydrocarbons such as lahydrofuran, 2-methylfuran, tetrahydropyran, diethyl acetal, etc., hexane, heptane, octane, isooctane, ligroin, cyclohexane, methylcyclohexane, toluene, xylene, ethylbenzene, styrene, divinylbenzene, etc., halogen hydrocarbons In, carbon tetrachloride, chloroform, methylene chloride, ethylene chloride, 1,1,1-trichloroethane, 1,1,2-trichloroethane, trichloroethylene, tetrachloroethylene, 1,1,1,2-tetrachloroethane In the case of polyhydric alcohols and derivatives thereof, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoacetate, diethylene glycol, In fatty acid systems such as lenglycol, dipropylene glycol, butanediol, hexylene glycol, 1,5-pentadiol, glycerin monoacetate, glycerin ethers, 1,2,6-hexanetriol, formic acid, acetic acid, propionic acid, In the case of nitrogen compounds such as entrained acid, isoentangled acid, isovaleric acid, and lactic acid, formamide, N, N-dimethylformamide, acetamide, acetonitrile, etc., and in the case of sulfur compounds, dimethyl sulfoxide and the like can be mentioned.
Among these, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, acetone, toluene, xylene, ethyl acetate, 1-pentanol and the like are particularly preferable. For the purpose of controlling aggregation, an alcohol or a polyhydric alcohol solvent is appropriately mixed. It may be used.
These organic solvents may be used alone or in combination, and the coating composition preferably contains 40% by mass to 98% by mass, and preferably 60% by mass to 97% by mass, as the total amount of the organic solvent. More preferably, it is most preferable to contain 70 mass%-95 mass%.

(Other additives)
The hard coat layer constituting the optical film of the present invention contains an organosilane compound, so-called sol component (hereinafter referred to as such), described in detail in the section of the low refractive index layer described later in the coating solution for forming the layer. It is preferable to improve the scratch resistance.

(Surfactant for light diffusion layer)
The hard coat layer of the present invention is a fluorine-based or silicone-based surfactant, or both for the hard coat layer, in particular, in order to ensure surface uniformity such as coating unevenness, drying unevenness, and point defects. It is preferable to contain in the coating composition. In particular, a fluorine-based surfactant is preferably used because an effect of improving surface defects such as coating unevenness, drying unevenness, and point defects of the optical film of the present invention appears with a smaller addition amount.
The purpose is to increase productivity by giving high-speed coating suitability while improving surface uniformity.

  Preferable examples of the fluorosurfactant include a fluoroaliphatic group-containing copolymer (sometimes abbreviated as “fluorine polymer”), and the fluoropolymer includes the following monomer (i): Acrylic resin, methacrylic resin characterized by containing corresponding repeating units, or containing repeating units corresponding to monomers (i) and (ii) below, and copolymerizable therewith Copolymers with vinyl monomers are useful.

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

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

(Ii) Monomer general formula (II) represented by the following general formula (II) copolymerizable with the above (i)

In the general formula (II), R ¹³ represents a hydrogen atom or a methyl group, Y represents an oxygen atom, a sulfur atom or —N (R ¹⁵ ) —, and R ¹⁵ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Specifically, it represents a methyl group, an ethyl group, a propyl group or a butyl group, preferably a hydrogen atom or a methyl group. Y is an oxygen atom, -N (H) -, and -N (CH ₃₎ - are preferred.
R ¹⁴ represents an alkyl group including a linear, branched or cyclic alkyl group or poly (alkyleneoxy) group having 4 to 20 carbon atoms which may have a substituent.

Examples of the substituent for the alkyl group of R ¹⁴ include a hydroxyl group, an alkylcarbonyl group, an arylcarbonyl group, a carboxyl group, an alkyl ether group, an aryl ether group, a halogen atom such as a fluorine atom, a chlorine atom, and a bromine atom, a nitro group, and a cyano group. Amino groups and the like, but not limited thereto. Examples of the linear, branched or cyclic alkyl group having 4 to 20 carbon atoms include a butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group and undecyl group which may be linear or branched. , Dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, octadecyl group, eicosanyl group, etc., and monocyclic cycloalkyl groups such as cyclohexyl group, cycloheptyl group and bicycloheptyl group, bicyclodecyl group, tricycloundecyl group, A polycyclic cycloalkyl group such as a tetracyclododecyl group, an adamantyl group, a norbornyl group, a tetracyclodecyl group, or the like is preferably used.

The amount of the fluoroaliphatic group-containing monomer represented by the general formula (I) used in the fluoropolymer used in the light diffusion layer of the present invention is 10 mol based on each monomer of the fluoropolymer. % Or more, preferably 15 to 70 mol%, more preferably 20 to 60 mol%.
The preferred weight average molecular weight of the fluoropolymer is preferably 3000 to 100,000, more preferably 5,000 to 80,000.
Furthermore, the preferable addition amount of the fluoropolymer used in the hard coat layer of the present invention is in the range of 0.001 to 5% by mass, preferably in the range of 0.005 to 3% by mass with respect to the coating solution. More preferably, it is the range of 0.01-1 mass%. When the addition amount of the fluorine-based polymer is 0.001% by mass or more, the effect is sufficient, and by setting it to 5% by mass or less, the coating film is sufficiently dried and good performance as a coating film (for example, reflection) Rate, scratch resistance).

  Hereinafter, although the example of the specific structure of the fluorine-type polymer containing the repeating unit corresponding to the fluoro aliphatic group containing monomer represented by general formula (I) is shown, it is not this limitation. In addition, the number in a formula shows the molar ratio of each monomer component. Mw represents a mass average molecular weight.

However, by using such a fluorine-based polymer, the functional group containing F atoms is segregated on the surface of the layer, so that the surface energy of the layer is lowered, and the low refractive index layer is overlaid on the light diffusion layer. When coated, there may be a problem that the antireflection performance deteriorates. This is presumably because minute unevenness that cannot be visually detected in the low refractive index layer deteriorates because the wettability of the curable composition used for forming the low refractive index layer deteriorates. To solve such problems, by adjusting the structure and amount of the fluorine-based polymer, the surface energy of the layer preferably in ^{20mN · m -1 ~50mN · m -1} , more preferably 30 mN · it is effective to control the m ^-1 ~40mN · m ^-1. In order to realize the surface energy as described above, F / C, which is a ratio of a peak derived from a fluorine atom and a peak derived from a carbon atom, measured by X-ray photoelectron spectroscopy is 0.1 to 1.5. Is preferred.

  In addition, when the upper layer is applied, by selecting a fluorine-based polymer that is extracted by the solvent that forms the upper layer, it is not unevenly distributed on the lower layer surface (= interface), so that adhesion between the upper layer and the lower layer is achieved. The surface energy of the light diffusing layer before coating the low refractive index layer can be reduced by preventing the decrease in surface free energy that can provide an optical film with high surface resistance and high scratch resistance even during high-speed coating. The purpose can also be achieved by controlling to the above. Examples of such a material include an acrylic resin, a methacrylic resin, and a vinyl copolymerizable therewith, containing a repeating unit corresponding to a fluoroaliphatic group-containing monomer represented by the following general formula (III): It is a copolymer with a monomer.

(Iii) Fluoroaliphatic group-containing monomer represented by the following general formula (III) General formula (III)

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

(Iv) A monomer represented by the following general formula (IV) that can be copolymerized with the above (iii) can also be used.
Formula (IV)

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

  Hereinafter, although the example of the specific structure of the fluorine-type polymer containing the repeating unit corresponding to the fluoro aliphatic group containing monomer represented by general formula (III) is shown, it is not this limitation. In addition, the number in a formula shows the molar ratio of each monomer component. Mw represents a mass average molecular weight.

  Further, if the reduction of the surface energy is prevented when the low refractive index layer is overcoated on the hard coat layer, the deterioration of the antireflection performance can be prevented. When applying a light diffusion layer, the surface tension of the coating solution is lowered by using a fluorine-based polymer to improve surface uniformity and maintain high productivity by high-speed coating. After coating the anti-glare layer, corona treatment, UV treatment, heat treatment, saponification Corona treatment is particularly preferred using surface treatment techniques such as treatment and solvent treatment, but the surface energy of the light diffusion layer before coating the low refractive index layer is controlled within the above range by preventing the surface free energy from decreasing. You can also achieve your goals.

Moreover, you may add a thixotropic agent in the coating composition for forming the hard-coat layer of this invention. Examples of the thixotropic agent include silica and mica of 0.1 μm or less. In general, the content of these additives is preferably about 1 to 10 parts by mass with respect to 100 parts by mass of the ultraviolet curable resin.
The viscosity (measured with a B-type viscometer) of the coating composition for forming the hard coat layer of the present invention is preferably 4 mPa · s to 300 mPa · s, more preferably 10 mPa · s to 200 mPa · s, and 20 mPa · s. ˜150 mPa · s is more preferable. If it exists in this range, a hard-coat layer can be efficiently apply | coated with a favorable application surface shape. In particular, by combining with a die coating method, it can be stably applied even at a relatively high viscosity.

In the optical film of the present invention, it is preferable that the intensity distribution of scattered light measured by a goniophotometer correlates with the viewing angle improvement effect. As a result of intensive studies, in order to achieve the desired viewing characteristics, the scattered light intensity at 30 °, which correlates particularly with the viewing angle improvement effect, is 0.01% to the light intensity at the exit angle 0 ° of the scattered light profile. It is preferably 0.2%, more preferably 0.02% to 0.15%, and particularly preferably 0.03% to 0.1%.
The scattered light profile can be measured for the created light scattering film using an automatic goniophotometer GP-5 manufactured by Murakami Color Research Laboratory.

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.

(Low refractive index layer)
The optical film of the present invention can be used as an antireflection film by having a layer having a refractive index lower than that of the transparent support (low refractive index layer) on the hard coat layer or the light diffusing hard coat layer.
The low refractive index layer is preferably a cured film formed by applying, drying and curing a curable composition containing, for example, a fluorine-containing polymer and / or a polyfunctional ionizing radiation curable monomer as a main component. Furthermore, it is also preferable to contain an organosilane compound, a hydrolyzate thereof and / or a partial condensate thereof.
The refractive index of the low refractive index layer of the antireflection film of the present invention is preferably 1.20 to 1.48, more preferably 1.30 to 1.46.

[Fluoropolymer for low refractive index layer]
The fluorine-containing polymer has a coefficient of dynamic friction of 0.03 to 0.20, a contact angle with water of 90 to 120 °, and a sliding angle of pure water of 70 ° or less when it is made into a cured coating, and heat or ionizing radiation. A polymer that is crosslinked by the above is preferable from the viewpoint of improving productivity in the case of applying and curing a roll film while conveying the web.
Further, when the optical film of the present invention is mounted on an image display device, the lower the peel strength from a commercially available adhesive tape, the easier it is to peel off after sticking a seal or memo, so the peel strength is 500 gf (4.9 N). The following is preferable, 300 gf (2.9 N) or less is more preferable, and 100 gf (0.98 N) or less is most preferable. Further, the higher the surface hardness measured with a microhardness meter, the harder it is to scratch. Therefore, the surface hardness is preferably 0.3 GPa or more, and more preferably 0.5 GPa or more.

  The fluorine-containing polymer used in the low refractive index layer is preferably a fluorine-containing polymer containing a fluorine atom in a range of 35 to 80% by mass and containing a crosslinkable or polymerizable functional group. In addition to hydrolyzate and dehydration condensate of alkyl group-containing silane compound [for example, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane], a fluorine-containing monomer unit and a crosslinking reactive unit are constituted. Examples thereof include a fluorine-containing copolymer as a unit. In the case of a fluorinated copolymer, the main chain preferably consists of only carbon atoms. That is, it is preferable that the main chain skeleton does not have an oxygen atom or a nitrogen atom.

  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- Dioxoles, etc.), (meth) acrylic acid partial or fully fluorinated alkyl ester derivatives (for example, Biscoat 6FM (manufactured by Osaka Organic Chemicals) and M-2020 (manufactured by Daikin)), fully or partially fluorinated vinyl ethers, etc. However, perfluoroolefins are preferable, and hexafluoropropylene is particularly preferable from the viewpoint of refractive index, solubility, transparency, availability, and the like.

  Examples of the crosslinking reactive unit include a structural unit obtained by polymerization of a monomer having a self-crosslinking functional group in the molecule such as glycidyl (meth) acrylate and glycidyl vinyl ether; carboxyl group, hydroxy group, amino group, sulfo group A structural unit obtained by polymerization of a monomer having, for example, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, maleic acid, crotonic acid, etc. And a structural unit in which a crosslinkable reactive group such as a (meth) acryloyl group is introduced 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).

  In addition to the fluorine-containing monomer unit and the cross-linking reactive unit, from the viewpoint of solubility in a solvent, film transparency, and the like, a monomer not containing a fluorine atom is appropriately copolymerized to introduce another polymerization unit. You can also. There are no particular limitations on the monomer units that can be used in combination, such as olefins [ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.], acrylic esters [methyl acrylate, methyl acrylate, ethyl acrylate, acrylic acid 2 -Ethylhexyl], methacrylates (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, vinyl toluene, α-methylstyrene, etc.), vinyl ethers (methyl) Vinyl ether, ethyl vinyl ether, cyclohexyl vinyl ether, etc.], vinyl esters [vinyl acetate, vinyl propionate, vinyl cinnamate, etc.], acrylamides [N-tertbutylacrylamide, N-silane] B hexyl acrylamide], methacrylamides, and acrylonitrile derivatives.

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

The fluorine-containing polymer particularly useful in the present invention is a random copolymer of perfluoroolefin and vinyl ethers or vinyl esters. In particular, it preferably has a group capable of undergoing crosslinking reaction alone (radical reactive group such as (meth) acryloyl group, ring-opening polymerizable group such as epoxy group and oxetanyl group).
These crosslinkable group-containing polymerized units preferably occupy 5 to 70 mol%, particularly preferably 30 to 60 mol% of the total polymerized units of the polymer.

  A preferred structure of the fluorine-containing polymer for the low refractive index layer used in the present invention is a copolymer represented by general formula 1 of JP-A-2005-283651. A particularly preferable structure is represented by the general formula 2 of the patent publication, and it is preferable to use the content and specific examples described in the publication. These polymers can be synthesized by the method described in the publication.

[Organosilane compound]
The hard coat layer and low refractive index layer of the present invention contain an organosilane compound, a so-called sol component (hereinafter sometimes referred to as this), in the coating liquid forming the layer, thereby providing scratch resistance. Can be improved. In particular, the low refractive index layer and the adjacent layer can achieve both antireflection performance and improved scratch resistance. This sol component is condensed by a drying and heating process after coating the coating solution to form a cured product and becomes a part of the binder of the above 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 represented by the following general formula 21.
General formula 21: (R < ¹ >) _m- Si (X) _4-m
In the general formula 21, R ¹ 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 represents a hydroxyl group or a hydrolyzable group, for example, an alkoxy group (preferably an alkoxy group having 1 to 5 carbon atoms, such as a methoxy group or an ethoxy group), a halogen atom (for example, Cl, Br, I or the like). ) And R ² COO (R ² is preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Examples include CH ₃ COO, C ₂ H ₅ COO, etc.), preferably An alkoxy group, particularly preferably a methoxy group or an ethoxy group. m represents an integer of 1 to 3, and preferably 1 or 2.

When R ¹ and X there are a plurality, the plurality of R ¹ and X may be different even in the same, respectively.
The substituent contained in R ¹ is not particularly limited, but a halogen atom (fluorine, chlorine, bromine, etc.), hydroxyl group, mercapto group, carboxyl group, epoxy group, alkyl group (methyl, ethyl, i-propyl, propyl, t-butyl etc.), aryl groups (phenyl, naphthyl etc.), aromatic heterocyclic groups (furyl, pyrazolyl, pyridyl etc.), alkoxy groups (methoxy, ethoxy, i-propoxy, hexyloxy etc.), aryloxy (phenoxy etc.) ), Alkylthio groups (methylthio, ethylthio, etc.), arylthio groups (phenylthio, etc.), alkenyl groups (vinyl, 1-propenyl, etc.), acyloxy groups (acetoxy, acryloyloxy, methacryloyloxy, etc.), alkoxycarbonyl groups (methoxycarbonyl, ethoxy) Carbonyl, etc.), aryloxy Carbonyl groups (phenoxycarbonyl, etc.), carbamoyl groups (carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N-methyl-N-octylcarbamoyl, etc.), acylamino groups (acetylamino, benzoylamino, acrylicamino, methacrylamino) Etc.), and these substituents may be further substituted.
R ¹ is preferably a substituted alkyl group or a substituted aryl group. Among these, an organosilane compound having a vinyl polymerizable substituent represented by the following General 22 is preferable.
Formula 22

In the general formula 22, R ₂ 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 preferable, and * -COO-** is particularly preferable. * Represents a position bonded to ═C (R ₂ ) —, and ** represents a position bonded to L.

  L 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, an alkylene group having a linking group therein is preferred, an unsubstituted alkylene group, an unsubstituted arylene group Further, an alkylene group having an ether or ester linking group inside is more preferable, an unsubstituted alkylene group, and an alkylene group having an ether or ester linking group inside is particularly preferable. 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.

l and m represent a molar ratio. l represents a number satisfying the mathematical formula of l = 100−m, and m represents a number from 0 to 50. As for m, the number of 5-40 is more preferable, and the number of 10-30 is especially preferable.
R _{3 to} R ₅ are preferably a chlorine atom, a hydroxyl group, an unsubstituted alkyl group, or an unsubstituted alkoxy group, more preferably a hydroxyl group or an alkoxy group having 1 to 6 carbon atoms, and a hydroxyl group or an alkoxy group having 1 to 3 carbon atoms. Particularly preferred.
R ₆ represents a hydrogen atom or an alkyl group. The alkyl group is preferably a methyl group or an ethyl group.
R ₇ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group or a hydroxyl group, preferably an alkyl group having 1 to 3 carbon atoms or a hydroxyl group.

  Specific examples of the starting material of the compound represented by the general formula 22 are shown below, but are not limited thereto.

  Of these, combinations of organosilanes selected from (M-1), (M-2), (M-25) and (M-19), (M-48), and (M-49) are particularly preferred. preferable.

  In order to obtain the effects of the present invention, the content of the organosilane containing a vinyl polymerizable group in the hydrolyzate of organosilane and / or its partial condensate is preferably 30% by mass to 100% by mass, and 50% by mass. % To 100% by mass is more preferable, 70% to 100% by mass is further preferable, and 90% to 100% by mass is particularly preferable.

  Content of organosilane containing vinyl polymerizable group in at least one of hydrolyzate of organosilane and partial condensate thereof according to the present invention (organosilane compound represented by general formula 21 or 22, hydrolyzate thereof And / or the content of the organosilane containing a vinyl polymerizable group in the organosilane raw material in the synthesis of the partial condensate thereof is preferably 50% by mass to 100% by mass, and 60% by mass to 95% by mass. More preferably, 70 mass%-10 mass% are especially preferable.

The sol component used in the present invention is prepared by hydrolysis and / or partial condensation of the organosilane.
In the hydrolysis condensation reaction, 0.05 to 2.0 mol, preferably 0.1 to 1.0 mol of water is added to 1 mol of the hydrolyzable group (X), and the presence of the catalyst used in the present invention. Under stirring at 25-100 ° C.

In at least one of the hydrolyzate of organosilane of the present invention and the partial condensate thereof, the mass average molecular weight of either the hydrolyzate of organosilane containing a vinyl polymerizable group or the partial condensate thereof is less than 300. When this component is removed, 450 to 20000 is preferable, 500 to 10,000 is more preferable, 550 to 5000 is still more preferable, and 600 to 3000 is still more preferable.
Of the components having a molecular weight of 300 or more in the hydrolyzate of organosilane and / or its partial condensate, the component having a molecular weight of more than 20000 is preferably 10% by mass or less, more preferably 5% by mass or less. More preferably, it is 3 mass% or less.

The hydrolyzate and 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, nitric acid; organic acids such as oxalic acid, acetic acid, butyric acid, maleic acid, citric acid, formic acid, methanesulfonic acid, toluenesulfonic acid; sodium hydroxide, potassium hydroxide, ammonia Inorganic bases such as triethylamine, pyridine, etc .; metal alkoxides such as triisopropoxyaluminum, tetrabutoxyzirconium, tetrabutyltitanate, dibutyltin dilaurate; metals such as Zr, Ti or Al as the central metal Metal chelate compounds and the like; F-containing compounds such as KF and NH ₄ F may be mentioned.
The said catalyst may be used independently or may use multiple types together.

  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 metal chelate compound includes an alcohol represented by a general formula R ⁷ OH (wherein R ⁷ represents an alkyl group having 1 to 10 carbon atoms) and R ⁸ COCH ₂ COR ⁹ (wherein R ⁸ has 1 carbon atom). To 10 alkyl groups, R ⁹ represents a C 1-10 alkyl group or a C 1-10 alkoxy group) 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 the general formula Zr (OR ⁷ ) _p1 (R ⁸ COCHCOR ⁹ ) _p2 , Ti (OR ⁷ ) _q1 (R ⁸ COCHCOR ⁹ ) _q2 , and Al (OR ⁷ ) _r1 (R ⁸ Those selected from the group of compounds represented by COCHCOR ⁹ ) _r2 are preferred.
Specific examples of these metal chelate compounds include tri-n-butoxyethyl acetoacetate zirconium, diisopropoxybis (acetylacetonato) titanium, diisopropoxyethyl acetoacetate aluminum, tris (ethyl acetoacetate) aluminum and the like. It is done. These metal chelate compounds can be used individually by 1 type or in mixture of 2 or more types. Moreover, the partial hydrolyzate of these metal chelate compounds can also be used.
The metal chelate compound is preferably used in a proportion of 0.01 to 50% by mass with respect to the organosilane compound.

In addition to the composition containing the sol component and the metal chelate compound, at least one of a β-diketone compound and a β-ketoester compound is added to the coating solution for the low refractive index layer or other layer used in the present invention. It is preferable.
What is used in the present invention is at least one of a β-diketone compound and a β-ketoester compound represented by the general formula R ⁸ COCH ₂ COR ⁹ .

  Specific examples of the β-diketone compound and β-ketoester compound include acetylacetone, methyl acetoacetate, ethyl acetoacetate and acetylacetone. These are preferably 0.1 to 50% by mass, more preferably 0.5 to 30% by mass, and most preferably 1 to 15% by mass of the total solid content of the containing layer (addition layer).

(Multifunctional ionizing radiation curable monomer)
The coating composition (coating solution) for forming the low refractive index layer according to the present invention may contain a polyfunctional ionizing radiation curable monomer. The monomer is coated with a coating composition, dried and then irradiated with ionizing radiation to cause chemical bonding to form a coating film. The ionizing radiation curable monomer is a monomer that is cured by a chemical reaction such as polymerization, addition polymerization, condensation polymerization or the like by ionizing radiation.
These monomers preferably contain a thermosetting group, and preferably contain, for example, a hydroxyl group, an alkoxy group, a carboxyl group, an amino group, an epoxy group, an isocyanate group, or the like.
The functional group of the polyionizing radiation curable monomer is preferably bifunctional or more, particularly preferably trifunctional or more. Specific examples of these ionizing radiation curable monomers include monomers described in the section of the antiglare hard coat layer described below.

  Specific examples of the polyionizing radiation curable monomer 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, dipentaerythritol hexa (Meth) acrylate, 1,2,3-cyclohexanetetramethacrylate, polyurethane polyacrylate, polyester polyacrylate), vinylbenzene and its derivatives (eg, 1, - divinylbenzene, 4-vinylbenzoic acid-2-acryloyl ethyl ester, 1,4-divinyl cyclohexanone), vinyl sulfones (e.g., divinyl sulfone), acrylamides (e.g., methylene bisacrylamide) and methacrylamide. Two or more of these monomers may be used in combination.

  The addition amount of the polyfunctional ionizing radiation curable monomer in the coating composition is generally 0.01 to 10% by mass, preferably 0.1 to 5% by mass.

(Inorganic fine particles with voids)
The low refractive index layer according to the present invention preferably contains inorganic fine particles having voids inside the particles in order to lower the refractive index. The voids are preferably porous or hollow, and may be fine particles having a structure in which inorganic fine particles are chain-connected to form voids, and among them, those having a hollow structure are particularly preferable.
The hollow inorganic fine particles are preferably hollow silica. The hollow silica fine particles preferably have a refractive index of 1.17 to 1.40, more preferably 1.17 to 1.35, and most preferably 1.17 to 1.30. The refractive index here represents the refractive index of the entire particle, and does not represent the refractive index of only the outer shell silica forming the hollow silica particles. At this time, when the radius of the cavity in the particle is a and the radius of the particle outer shell is b, the porosity x calculated from the following formula (III) is preferably 10 to 60%, more preferably 20 to 60. %, Most preferably 30-60%.
(Formula ^{III): 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. Rate particles are not used. The refractive index of these hollow silica particles can be measured with an Abbe refractometer (manufactured by Atago Co., Ltd.).
Moreover, the manufacturing method of hollow silica is described, for example in Unexamined-Japanese-Patent No. 2001-233611 and 2002-79616.

The amount of the hollow silica is ^preferably from ^{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 fine unevenness is reduced on the surface of the low refractive index layer, and the appearance such as black tightening and the integrating sphere reflectance are improved.
The average particle diameter of the hollow silica is preferably 30% or more and 150% or less, more preferably 35% or more and 80% or less, and still more preferably 40% or more and 60% or less of the thickness of the low refractive index layer. That is, if the thickness of the low refractive index layer is 100 nm, the particle size of the hollow silica is preferably 30 nm or more and 150 nm or less, more preferably 35 nm or more and 80 nm or less, and still more preferably 40 nm or more and 60 nm or less.
When the particle diameter of the silica fine particles is in the above range, the refractive index is lowered, fine irregularities are reduced on the surface of the low refractive index layer, and the appearance such as black tightening and the integrating sphere reflectance are improved. The silica fine particles may be either crystalline or amorphous, and are preferably monodisperse particles. 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 hollow silica can be determined from an electron micrograph.

In the present invention, silica particles having no voids can be used in combination with hollow silica. The preferred particle size of silica without voids is 30 nm to 150 nm, more preferably 35 nm to 80 nm, and most preferably 40 nm to 60 nm.
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 (also referred to as “small size particle fine silica particles”) is used as silica fine particles having the above particle size (“large size particles”). It is preferably used in combination with “diameter silica fine particles”.
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.
The average particle size of the silica fine particles having a small size is preferably 1 nm to 20 nm, more preferably 5 nm to 15 nm, and particularly preferably 10 nm to 15 nm. Use of such silica fine particles is preferable in terms of raw material costs and a retaining agent effect.

  Silica fine particles are treated by physical surface treatment such as plasma discharge treatment or corona discharge treatment in order to stabilize dispersion in the dispersion or coating solution, or to improve the affinity and binding to the binder component. Chemical surface treatment with a surfactant, a coupling agent, or the like may be performed.

(Fluorine and / or silicone compounds)
The low refractive index layer according to the present invention preferably contains fluorine and / or a silicone compound. By these, surface free energy can be reduced and antifouling property, smoothness, water resistance, etc. can be improved.
As these compounds, known silicone compounds or fluorine compounds can be used. In the case of adding these, 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. Yes, particularly preferably 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 more preferable that it is 50,000 or less, It is especially preferable that it is 3000-30000, It is most preferable that it is 10,000-20000. Although there is no restriction | limiting in particular in silicone atom content of a silicone type compound, it is preferable that it is 18.0 mass% or more, it is especially preferable that it is 25.0-37.8 mass%, and 30.0-37.0. Most preferably, it is mass%. Examples of preferable silicone compounds include X-22-174DX, X-22-2426, X-22-164B, X22-164C, X-22-170DX, X-22-176D, X, manufactured by Shin-Etsu Chemical Co., Ltd. -22-1821, FL100 (named above), Chisso Corporation, FM-0725, FM-7725, FM-4421, FM-5521, FM6621, FM-1121, Gelest DMS-U22, RMS- 033, RMS-083, UMS-182, DMS-H21, DMS-H31, HMS-301, FMS121, FMS123, FMS131, FMS141, FMS221 (named above), GE Toshiba Silicone Co., Ltd. TSF4460, etc. However, it is not limited to these.

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.), for example, a branched structure (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.) and alicyclic structures (preferably 5-membered or 6-membered rings such as perfluorocyclohexyl group, perfluorocyclopentyl group) Or an alkyl group substituted with these, and may have an ether bond (for example, CH ₂ OCH ₂ CF ₂ CF ₃ , CH ₂ CH ₂ OCH ₂ C ₄ F ₈ H, CH ₂ CH ₂ OCH ₂ CH ₂ C ₈ F ₁₇ , CH ₂ 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 polymer or an oligomer with a compound not containing a fluorine atom, and the molecular weight is not particularly limited. Although there is no restriction | limiting in particular in fluorine atom content of a fluorine-type compound, It is preferable that it is 20 mass% or more, It is especially preferable that it is 30-70 mass%, It is most preferable that it is 40-70 mass%. Examples of preferred fluorine compounds include Daikin Chemical Industries, R-2020, M-2020, R-3833, M-3833 (named above), Dainippon Ink & Chemicals, MegaF -171, F-172, F-179A, Defender MCF-300 (named above), MOFAPER F series made by NOF Corporation, etc., but are not limited to these.

  The fluorine and / or silicon-containing compound preferably contains at least one group having reactivity with the binder in the molecule. Examples of preferable reactive groups include thermosetting active hydrogen atoms, hydroxyl groups, melamine, active energy ray-curable (meth) acryloyl groups, and epoxy groups, and are melamine or (meth) acryloyl groups. Particularly preferred.

  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 low refractive index layer-forming composition of the present invention takes the form of a liquid and contains the aforementioned organosilane compound, its hydrolyzate and / or its partial condensate, a fluorine-containing polymer, and optionally, inorganic fine particles, fluorine and It is prepared by dissolving various additives such as silicone compounds, other binders, radical polymerization initiators in an appropriate solvent.
In this case, 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, and particularly preferably 1 to 20% by mass. %.
10-500 nm is preferable, as for the layer thickness after hardening of a low-refractive-index layer, 20-300 nm is more preferable, and 30-200 nm is further more preferable.

  In addition, it is not always advantageous to add an additive such as a curing agent from the viewpoint of the film hardness of the low refractive index layer, but from the viewpoint of interfacial adhesion with the high refractive index layer, a polyisocyanate compound, aminoplast, A small amount of a curing agent such as a polybasic acid or its anhydride may 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.

  The low refractive index layer according to the present invention is appropriately added with a known cationic surfactant or a dustproof agent such as a polyoxyalkylene compound, an antistatic agent, etc. for the purpose of imparting dustproof properties and antistatic properties. You can also 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 preferred compounds include Dainippon Ink & Chemicals, MegaFuck F-150 (trade name), Toray Dow Corning, SH-3748 (trade name), and the like. It is not done.

Next, other layers in the optical film of the present invention will be described.
(Antistatic layer)
The antistatic layer can be formed by, for example, applying a conductive coating solution containing conductive fine particles and a reactive curable resin, or depositing or sputtering a metal or metal oxide that forms a transparent film. Conventionally known methods such as a method of forming a conductive thin film can be listed. The antistatic layer can be formed directly on the base film or via a primer layer that strengthens adhesion to the base film. Further, the antistatic layer can be used as a part of the antireflection film. In this case, when used in a layer close to the outermost layer, sufficient antistatic properties can be obtained even if the film is thin.

The thickness of the antistatic layer is preferably from 0.01 to 10 μm, more preferably from 0.03 to 7 μm, and even more preferably from 0.05 to 5 μm. The surface resistance value (log SR) at 25 ° C. and 55% RH of the antistatic layer of the present invention is preferably 12 Ω / sq or less, and more preferably 10 Ω / sq or less. Further, the surface resistance value is preferably 5 Ω / sq or more in order to be compatible with the transparency of the coating film. That is, the surface resistance value of the antistatic layer of the present invention at 25 ° C. and 55% RH is preferably 5 to 12 Ω / sq, and more preferably 5 to 10 Ω / sq.
The surface resistance of the antistatic layer can be measured by a four probe method.
By setting the surface resistance of the antistatic layer within the above range, an antireflection film that is transparent and has good dust resistance can be obtained.

Further, the antistatic layer is preferably an electron conduction type in which the surface resistance value hardly changes due to environmental temperature and humidity.
The antistatic layer is preferably substantially transparent. Specifically, the haze of the antistatic layer is preferably 10% or less, more preferably 5% or less, further preferably 3% or less, and most preferably 1% or less. . Further, the transmittance of light having a wavelength of 550 nm is preferably 50% or more, more preferably 60% or more, further preferably 65% or more, and most preferably 70% or more.
The antistatic layer of the present invention has excellent strength, and the specific antistatic layer has a pencil hardness of 1 kg (as defined in JIS-K-5400), preferably H or higher, preferably 2H or higher. Is more preferably 3H or more, and most preferably 4H or more.

  The conductive inorganic fine particles contained in the antistatic layer according to the present invention are preferably formed from a metal oxide or nitride. Examples of metal oxides or nitrides include tin oxide, indium oxide, zinc oxide and titanium nitride. Among these, tin oxide and indium oxide are particularly preferable. The conductive inorganic fine particles are mainly composed of oxides or nitrides of these metals, and can further contain other elements. The main component means a component having the largest content (mass%) among the components constituting the particles. Examples of other elements include Ti, Zr, Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Al, Mg, Si, P, S, B, Nb, In, V and halogen atoms are included. In order to increase the conductivity of tin oxide and indium oxide, it is preferable to add Sb, P, B, Nb, In, V and a halogen atom. Particularly preferred are tin oxide containing Sb (ATO) and indium oxide containing Sn (ITO). The ratio of Sb in ATO is preferably 3 to 20% by mass. The ratio of Sn in ITO is preferably 5 to 20% by mass.

The antistatic layer can use a crosslinked polymer as a binder. The crosslinkable polymer preferably has an anionic group. In the crosslinkable polymer having an anionic group, the main chain of the polymer having an anionic group has a crosslinked structure. The anionic group has a function of maintaining the dispersion state of the conductive inorganic fine particles. The crosslinked structure has a function of strengthening the antistatic layer by imparting a film forming ability to the polymer.
The crosslinkable polymer having an anionic group is preferably a polymer having a polyolefin (saturated hydrocarbon), polyether, polyurea, polyurethane, polyester, polyamine, polyamide or the like as a main chain, and a melamine resin. Among them, 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.

[Transparent support]
A plastic film is preferably used as the transparent support of the optical film of the present invention. Examples of the polymer forming the plastic film include cellulose acylate (eg, triacetyl cellulose, diacetyl cellulose, typically TAC-TD80U, TD80UF, etc., manufactured by Fuji Film), polyamide, polycarbonate, polyester (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. Single-layer triacetyl cellulose is prepared by drum casting or band casting disclosed in Japanese Patent Laid-Open No. 7-11055 and the like. It is prepared by the so-called co-casting method disclosed in Japanese Patent Publication No. -94725 and Japanese Patent Publication No. Sho 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 (also referred to as a dope) to which various additives such as a plasticizer, an ultraviolet absorber, a deterioration preventing agent, a slipping agent, and a peeling accelerator are added as necessary is a horizontal endless solution. When casting by a dope supply means (also 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. Co-cast a low concentration dope on both sides of the cellulose ester dope, and dry the film to some extent on the support to release the rigid film. In a method comprising removing the various solvents is passed through the drying section by the conveying means.
The refractive index of triacetyl cellulose is preferably 1.46 to 1.49, more preferably 1.47 to 1.48.

A typical solvent for dissolving triacetylcellulose 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.

  When the optical film of the present invention is used in a liquid crystal display device, it is preferably disposed on the outermost surface of the display by providing an adhesive layer on one side. Moreover, you may combine the antireflection film and polarizing plate of this invention. 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 optical film of the present invention is disposed on the outermost surface of a display by providing an adhesive layer on one side or used as it is as a protective film for a polarizing plate, the optical film on the transparent support is sufficient for adhesion. It is preferable to carry out a saponification treatment after forming the outermost layer. 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 polarizing 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 that it is difficult for dust to enter between the polarizing film and the antireflection film when adhered to the polarizing film, and this prevents point defects caused by 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, and particularly preferably 20 ° or less.

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

[Application method]
The optical film of the present invention can be formed by the following method, but is not limited to this method. First, a coating solution containing components for forming each layer is prepared. Next, a coating solution for forming various functional layers is applied onto the transparent support by dip coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating or die coating. Although heated and dried, the micro gravure coating method, the wire bar coating method, and the die coating method are more preferable, and the die coating method is particularly preferable. Further, it is most preferable to apply using a die whose configuration is devised as described later.
Thereafter, the monomer for forming the functional layer is polymerized and cured by light irradiation or heating. Thereby, a functional layer is formed. If necessary, the functional layer can be a plurality of layers.
Next, a coating solution for forming a low refractive index layer is applied onto the functional layer in the same manner, and is irradiated with light or heated (irradiated with ionizing radiation such as ultraviolet rays, preferably irradiated with ionizing radiation under heating. Cured) to form a low refractive index layer. In this way, the optical film of the present invention is obtained.

[Configuration of die coater]
FIG. 1 is a cross-sectional view of a coater using a slot die used in the practice of the present invention. The coater 10 is applied to the web 12 supported by the backup roll 11 and continuously applied from the slot die 13 as a bead 14a to form a coating film 14b on the web 12.

  Inside the slot die 13, a pocket 15 and a slot 16 are formed. The cross section of the pocket 15 is configured by a curve and a straight line, and may be, for example, a substantially circular shape as shown in FIG. 2 or a semicircular shape. 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 12, and has a cross-sectional shape in the width direction of the slot die 13 like 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 formed in a tapered shape, and the tip is a flat portion 18 called a land. In this land 18, the upstream side in the running direction of the web 12 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.

  2A and 2B show the cross-sectional shape of the slot die 13 in comparison with the conventional one. FIG. 2A shows the slot die 13 suitable for the present invention, and FIG. 2B shows the conventional slot die 30. ing. In the conventional slot die 30, the distance between the upstream lip land 31a and the web 12 of the downstream lip land 31b is equal. In (B), 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 accurately performed.

  The land length IUP of the upstream lip land 18a is not particularly limited, but a range of 100 μm to 1 mm is preferably employed. The land length ILO 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 ILO of the downstream lip is shorter than 30 μm, the edge or land of the tip lip 17 is likely to be chipped, streaks are likely to occur in the coating film, and as a result, application becomes 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 ILO of the downstream lip is longer than 100 μm, the bead itself cannot be formed, so that it is impossible to perform thin layer coating.

  Further, the downstream lip land 18b has an overbite shape closer to the web 12 than the upstream lip land 18a. Therefore, the degree of decompression can be reduced, and a bead suitable for thin film coating can be formed. The difference in distance between the downstream lip land 18b and the web 12 of the upstream 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 12 indicates a gap between the downstream lip land 18 b and the web 12.

  FIG. 3 is a perspective view showing a slot die and its periphery in the coating process used in the practice of the present invention. On the opposite side of the web 12 from the traveling direction, a 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 includes a back plate 40a and a side plate 40b for maintaining its operating efficiency, and there are gaps GB and GS between the back plate 40a and the web 12, and between the side plate 40b and the web 12, respectively. Exists.

  FIG. 4 is a cross-sectional view showing the vacuum chamber 40 and the web 12 that are close to each other. The side plate 40b and the back plate 40a may be integrated with the chamber body as shown in FIG. 5, or may be structured to be fastened to the chamber with screws or the like.

  Regardless of the structure, the portions actually opened between the back plate 40a and the web 12 and between the side plate 40b and the web 12 are defined as gaps GB and GS, respectively. The clearance GB between the back plate 40a of the decompression chamber 40 and the web 12 is the distance from the uppermost end of the back plate 40a to the web 12 when the decompression chamber 40 is installed below the web 12 and the slot die 13 as shown in FIG. Indicates a gap.

  The gap GB between the back plate 40a and the web 12 is preferably set larger than the gap GL between the tip lip 17 of the slot die 13 and the web 12. Thereby, the pressure reduction degree change of the bead vicinity resulting from the eccentricity of the backup roll 11 can be suppressed.

  For example, when the gap GL between the tip lip 17 of the slot die 13 and the web 12 is not less than 30 μm and not more than 100 μm, the gap GB between the back plate 40 a and the web 12 is preferably not less than 100 μm and not more than 500 μm.

[Material and accuracy]
The longer the length of the tip lip 17 on the traveling direction side of the web 12 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, the bead is caused by a slight disturbance. Becomes unstable. Therefore, it is preferable that the fluctuation width in the slot die width direction is within 20 μm.

  Further, when the material of the tip lip 17 of the slot die is made of a material such as stainless steel, the length of the slot die tip lip 17 in the web running direction is set to 30 as described above. Even in the range of ˜100 μm, the accuracy of the tip lip 17 cannot be satisfied.

  Therefore, in order to maintain high processing accuracy, it is important to use a cemented carbide material as described in Japanese Patent No. 2817053. Specifically, at least the tip lip 17 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 also 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 achieve highly accurate coating, the length of the land on the web running direction side of the tip lip 17 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 the 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 between the tip lip 17 and the backup roll 11 is set so that the fluctuation width of the gap in the slot die width direction is 5 μm or less.

  The micro gravure coating method used in the present invention is a gravure roll having a diameter of about 10 to 100 mm, preferably about 20 to 50 mm and engraved with a gravure pattern on the entire circumference, below the support and in the transport direction of the support. The gravure roll is rotated in reverse with respect to the gravure roll, the excess coating liquid is scraped off from the surface of the gravure roll by a doctor blade, and a fixed amount of the coating liquid is removed from the support in a position where the upper surface of the support is in a free state. The coating method is characterized in that the coating liquid is transferred onto the lower surface for coating. A roll-shaped transparent support is continuously unwound, and at least one layer of at least one of a hard coat layer or a low refractive index layer containing a fluorine-containing polymer is provided on one side of the unwound support. Can be applied by.

  As coating conditions by the micro gravure coating method, the number of gravure patterns engraved on the gravure roll is preferably 50 to 800 / inch, more preferably 100 to 300 / inch, and the depth of the gravure pattern is 1 to 600 μm. Is preferable, 5 to 200 μm is more preferable, the rotation speed of the gravure roll is preferably 3 to 800 rpm, more preferably 5 to 200 rpm, and the conveyance speed of the support is 0.5 to 100 m / min. It is preferably 1 to 50 m / min.

  The polarizing plate is mainly composed of two protective films that sandwich the polarizing film from both sides. The optical film or 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. The manufacturing cost of a polarizing plate can be reduced because the optical film or antireflection film of the present invention also serves as a protective film. Moreover, by using the optical film or 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 properties 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 progress of the film is such that the difference between the moving speeds in the longitudinal direction of the holding device is within 3%, and the angle formed between the moving direction of the film at the exit of the process of holding both ends of the film and the substantial stretching direction of the film is inclined by 20 to 70 °. The film can be produced by a stretching method in which the direction is bent while holding both ends of the film. In particular, those inclined by 45 ° 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.
As the optical compensation film, a known film can be used, but in terms of widening the viewing angle, an optical compensation layer made of a compound having a discotic structural unit described in JP-A No. 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.

Of the two protective films of the polarizer, it is preferable that the transparent support of at least one protective film satisfies the following formulas (I) and (II) because the display improvement effect from the oblique direction of the liquid crystal display screen is high. In particular, it is particularly preferable that the transparent support of the present invention satisfies the following formulas (I) and (II).
(I): 0 ≦ Re (630) ≦ 10 and | Rth (630) | ≦ 25
(II): | Re (400) −Re (700) | ≦ 10 and | Rth (400) −Rth (700) | ≦ 35

  The optical film, antireflection film, or polarizing plate of the present invention is 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). Can be applied. Since the optical film, the antireflection film, or the polarizing plate of the present invention has a transparent support, it is used by bonding the transparent support side to the image display surface of the image display device, that is, a hard coat layer or a low It is preferable to arrange the refractive index layer so that it is on the viewing side.

  When the optical film or antireflection film of the present invention is used as one side of a surface protective film of a polarizing film, twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), in-plane switching (IPS) ), Transmissive, reflective, or transflective liquid crystal display devices such as an optically 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-). 176625 (in Japanese Patent Publication No. 176625), and (2) a liquid crystal cell (SID97, Digest of tech. Papers (Proceedings) 28 (1997) 845 in which the VA mode is multi-domained (in MVA mode) for widening the viewing angle. ), (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 referred to as an OCB (Optically Compensatory Bend) liquid crystal mode. The bend alignment mode liquid crystal display device has an advantage of high response speed.

Furthermore, as a whole including a liquid crystal cell in a bend alignment mode and a polarizing plate including an optically anisotropic layer, the optical characteristics satisfying the following formula (1 ′) are obtained in any of the wavelength 450 nm, wavelength 550 nm, and wavelength 630 nm measurements. It is preferable to have a display improvement effect from an oblique direction of the liquid crystal display screen, and it is particularly preferable that a polarizing plate using the optical film of the present invention as a protective film satisfies the following formula (1 ′).
Formula (1 ′): 0.05 <(Δn × d) / (Re × Rth) <0.20
[In the formula (1 ′), Δn is the intrinsic birefringence of the rod-like liquid crystalline molecule in the liquid crystal cell; d is the thickness of the liquid crystal layer of the liquid crystal cell in nm; Re is the optically anisotropic layer Rth is the retardation value in the thickness direction of the entire optically anisotropic layer.

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

  In particular, for a TN mode or IPS mode liquid crystal display device, as described in JP-A-2001-100043, an optical compensation film having a viewing angle expansion effect 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 liquid a-1)
In a 1,000 ml reaction vessel equipped with a thermometer, nitrogen introduction tube, and dropping funnel, 187 g (0.80 mol) acryloxyoxypropyltrimethoxysilane, 29.0 g (0.21 mol) methyltrimethoxysilane, 320 g methanol ( 10 mol) and 0.06 g (0.001 mol) of KF were charged, and 17.0 g (0.94 mol) of water was slowly added dropwise at room temperature with stirring. After completion of the dropwise addition, the mixture was stirred at room temperature for 3 hours, and then heated and stirred for 2 hours under methanol reflux. Thereafter, the low boiling point component was distilled off under reduced pressure and further filtered to obtain 120 g of sol liquid a-1. As a result of GPC measurement of the substance thus obtained, the mass average molecular weight was 1500, and among the components higher than the oligomer component, the component having a molecular weight of 1000 to 20000 was 30%.

  Moreover, from the measurement result of 1H-NMR, the structure of the obtained substance was a structure represented by the following general formula.

Average compositional _{formula: (CH 2 = CHCOO-C} 3 H 6) 0.8 (CH 3) 0.2 SiO 0.86 (OCH 3) 1.28
Furthermore, the condensation rate α as determined by ²⁹ Si-NMR was 0.59. From this analysis result, it was found that the silane coupling agent sol was mostly composed of a linear structure.
From the gas chromatography analysis, the raw material acryloxypropyltrimethoxysilane had a residual rate of 5% or less.

(Synthesis of perfluoroolefin copolymer (1))

Into a stainless steel autoclave with a stirrer of 100 ml, 40 ml of ethyl acetate, 14.7 g of hydroxyethyl vinyl ether and 0.55 g of dilauroyl peroxide were charged, and the inside of the system was deaerated and replaced with nitrogen gas. Furthermore, 25 g of hexafluoropropylene (HFP) was introduced into the autoclave and the temperature was raised to 65 ° C. The pressure when the temperature in the autoclave reached 65 ° C. was 5.4 kg / cm ² . The reaction was continued for 8 hours while maintaining the temperature, and when the pressure reached 3.2 kg / cm ² , the heating was stopped and the mixture was allowed to cool. When the internal temperature dropped to room temperature, unreacted monomers were driven out, the autoclave was opened, and the reaction solution was taken out. The obtained reaction solution was poured into a large excess of hexane, and the polymer was precipitated by removing the solvent by decantation. Further, this polymer was dissolved in a small amount of ethyl acetate and reprecipitated twice from hexane to completely remove the residual monomer. After drying, 28 g of polymer was obtained. Next, 20 g of the polymer was dissolved in 100 ml of N, N-dimethylacetamide, and 11.4 g of acrylic acid chloride was added dropwise under ice cooling, followed by stirring at room temperature for 10 hours. Ethyl acetate was added to the reaction solution, washed with water, the organic layer was extracted and concentrated, and the resulting polymer was reprecipitated with hexane to obtain 19 g of perfluoroolefin copolymer (1). The obtained polymer had a refractive index of 1.42.

(Composition of coating liquid H-1 for transparent hard coat layer)
Bifunctional acrylate compound (A-1 in the text) 15.0 g
DPHA: 35.0 g with dipentaerythritol pentaacrylate
Dipentaerythritol hexaacrylate mixture
[Nippon Kayaku Co., Ltd.]
Methyl isobutyl ketone 42.0g
Methyl ethyl ketone 8.0g
Irgacure 184 (C-18 in the text) 4.0 g

(Compositions of coating liquids H-2 to H-16 for transparent hard coat layer and comparative examples HH-1 to 6)
H-1 except that the bifunctional acrylate compound (A-1), DPHA, and photopolymerization initiator (Irgacure 184, C-18) in the transparent hard coat layer coating solution H-1 were changed as shown in Table 1 below. Is the same.

  Each of the coating solutions of H-1 to H-16 and HH1 to 6 was filtered through a polypropylene filter having a pore size of 10 μm to prepare a coating solution for each transparent hard coat layer.

Composition of coating liquid J-1 for light diffusing hard coat layer Bifunctional acrylate compound (A-1 in the text) 20 g
PET-30: pentaerythritol triacrylate, 30 g
A mixture of pentaerythritol tetraacrylate
[Nippon Kayaku Co., Ltd.]
Methyl isobutyl ketone 28.5g
Methyl ethyl ketone 7.0g
Irgacure 184 (C-18 in the text) 2.0g
SX-500H (30%): average particle size 5 μm cross-linked 14.5 g
Polystyrene particles [refractive index 1.60, manufactured by Soken Chemical Co., Ltd., 30% methyl isobutyl ketone dispersion,
Used after dispersion for 20 minutes at 10,000 rpm in a Polytron disperser]
FP-132: Fluorine-based surface modifier, JP2005
A fluororesin-containing polymer represented by the following structural formula described in paragraph No. 0207 of Japanese Patent No. 316422 (50 represents mol%). 0.75g
Sol liquid a-1 10.0g

(Composition of coating liquids J-2 to J-16 for light diffusing hard coat layer, comparative examples JJ-1 to JJ-5)
Except that the bifunctional acrylate compound (A-1), PET-30, Irgacure 184, and SX-500H (30%) of the coating liquid J-1 for light diffusing hard coat were changed as shown in Table 2 below, J- Same as 1.

  Each of the coating liquids J-1 to J-16 and JJ-1 to 5 was filtered through a polypropylene filter having a pore diameter of 30 μm to prepare a coating liquid for each light diffusible hard coat layer.

Composition of coating liquid L-1 for low refractive index layer JTA-113 63.7g
MEK-ST-L 6.4g
Sol solution a-1 2.9 g
Methyl ethyl ketone 24.5g
Cyclohexanone 2.9g

Composition of coating liquid L-2 for low refractive index layer Perfluoroolefin copolymer (1) (solid content 30%)
13.0g
MEK-ST-L 6.0g
X-22-164C 0.15g
Irgacure 907 0.23g
Sol liquid a-1 0.6g
Methyl ethyl ketone 77.2g
2.8 g of cyclohexanone

Composition of coating liquid L-3 for low refractive index layer JTA-113 73.0 g
Hollow silica liquid 19.5g
Sol liquid a-1 1.7 g
Methyl ethyl ketone 47.5g
Cyclohexanone 5.3g

  About the coating liquid for low refractive index layers of said L-1, L-2, L-3, it filtered with the filter made from a polypropylene with a hole diameter of 1 micrometer, and prepared the coating liquid for each low refractive index layer. The refractive index of the layer formed by the coating liquids L-1 and L-2 was 1.44, and the refractive index of the layer by L-3 was 1.39.

The compounds used in H-1 to 16, HH-1 to 6, J-1 to 16, JJ-1 to 3, and L-1 to 3 will be supplemented below.
SX-350H: average particle size 3.0 μm crosslinked polystyrene particles [refractive index 1.60, manufactured by Soken Chemical Co., Ltd., 30% methyl isobutyl ketone dispersion, used after dispersion at 10,000 rpm in a Polytron disperser for 20 minutes]
Desolite Z7526: Hard coating agent containing SiO ₂ fine particles [manufactured by JSR Corporation]
Desolite Z7404: Hard coating agent containing ZrO ₂ fine particles [refractive index 1.62, solid content concentration 60.4%, manufactured by JSR Corporation]
MEK-ST-L: Colloidal silica dispersion [MEK-ST particle size difference, average particle size 45 nm, solid content concentration 30%, manufactured by Nissan Chemical Co., Ltd.]
Hollow silica liquid: KBM-5103 (manufactured by Shin-Etsu Chemical Co., Ltd.) surface-modified hollow silica sol [surface modification rate vs. 30% by mass of silica, CS-60 IPA, refractive index 1.31, average particle size 60 nm, shell thickness 10 nm, Solid content concentration 18.2%, manufactured by Catalyst Kasei Kogyo Co., Ltd.]
X22-164C: Reactive silicone [manufactured by Shin-Etsu Chemical Co., Ltd.]
JTA113: Thermally crosslinkable fluorine-containing polymer having a refractive index of 1.44 containing polysiloxane and hydroxyl group (solid content concentration 6%, manufactured by JSR Corporation)
EB-1290K, EB-5129: UV curable urethane acrylate compound (manufactured by Daicel-Cytec)
UN-3320HC, UN-904: UV curable urethane acrylate compound (manufactured by Negami Kogyo)
Aronix M-9050: UV curable polyester acrylate compound (manufactured by Toa Gosei)
ATMMT: Pentaerythritol tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)

  The viscosity of the coating solution for the transparent hard coat layer was as shown in Table 1. (Unit: mPa · s)

  Moreover, the viscosity of the coating solution for light diffusing hard coat layer was as shown in Table 2. (Unit: mPa · s)

[Example 1]
[Production and Evaluation of Optical Film Samples 101 to 117]
(1) Application of light diffusing hard coat layer
A triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Film Co., Ltd., refractive index 1.48) having a thickness of 80 μm is unrolled in a roll form, and the coating liquid for the light diffusing hard coat layer is shown in Table 3. In the die coating method using the slot die as described above, the coating was performed at a conveyance speed of 30 m / min, dried at 60 ° C. for 150 seconds, and further air-cooled metal halide of 160 W / cm under a nitrogen purge. Using a lamp (manufactured by Eye Graphics Co., Ltd.), an ultraviolet ray having an illuminance of 400 mW / cm ² and an irradiation amount of 250 mJ / cm ² was irradiated to form a light diffusing hard coat layer. The contents of the hard coat layer are as shown in Table 3 below. The thickness was adjusted by the coating amount.

(2) Coating of low refractive index layer The slot die is used so that the coating liquid for the low refractive index layer has the structure shown in Table 3 on the surface coated with the light diffusing hard coat layer. The coating was carried out under the condition of a transfer speed of 30 m / min, dried at 120 ° C. for 75 seconds, heated for another 10 minutes, and then air-cooled metal halide lamp (I Graphics Co., Ltd.) under nitrogen purge. The low refractive index layer having a thickness of 100 nm was formed and wound up by irradiating with ultraviolet rays having an illuminance of 400 mW / cm ² and an irradiation amount of 240 mJ / cm ² .

(Preparation of optical film sample)
The optical film sample was produced by the combination of layers as shown in Table 3 below by the above method. In Table 3, layers were coated on the support in order from the coating layer described on the left side.

  Table 4 shows the ratio of the thickness of the light diffusible hard coat layer to the thickness of the support and the ratio of the particle diameter to the thickness of the light diffusible hard coat layer.

(Saponification of optical film)
After coating, the sample 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 produced 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 manner, saponified optical films (invention samples 101 to 117) were produced.

(Evaluation of optical film)
About these obtained optical film samples, the following items were evaluated. The results are shown in Table 5.

(1) Average reflectance The back side of the film was roughened with sandpaper, then treated with black ink, and the back side was removed, using the spectrophotometer (manufactured by JASCO Corporation). In the wavelength region of 380 to 780 nm, specular spectral reflectance at an incident angle of 5 ° was measured. The arithmetic average value of the specular reflectance of 450-650 nm was used for the result.

(2) Haze The haze value was measured according to JIS-K7136.
(3) Image clarity The transmitted image clarity was measured with an optical comb width of 0.5 mm in accordance with JIS K7105.

(4) Blackening property The feeling of blackening was sensory-evaluated about the liquid crystal display device which has arrange | positioned the polarizing plate which stuck the optical film on the visual recognition side surface. The evaluation method is a method in which multiple displays are arranged in parallel and compared at the same time. From the front, the blackness when the power is turned off and the blackness (black image) when the power is turned on are compared for each film, and evaluated according to the following criteria. did. It was expressed by the standard that the stronger the blackness, the stronger the tightness of the screen.
◎: The screen appears strong and dark.
○: Black but faintly gray and the screen looks slightly distorted.
Δ: Black but gray, and the screen is not tight.
×: The color is very gray and there is no tightness on the screen.

(5) Anti-glare properties The entire back side of the coated surface of the obtained film is painted with black magic ink, and the exposed fluorescent lamp (8000 cd / m ² ) without louver is projected from a 5 degree angle, from a -5 degree direction. The degree of blurring of the reflected image when observed from an angle of 45 degrees and observed from a direction of -45 degrees was evaluated according to the following criteria.
◎: Fluorescent lamp outline is slightly observed at -5 degrees and -45 degrees. ◯: Fluorescent lamp outline is slightly observed at -5 degrees, but the outline is relatively clear at -45 degrees. I understand.
Δ: The outline of the fluorescent lamp can be seen relatively clearly even at −5 degrees or −45 degrees.
X: The outline of the fluorescent lamp is clearly visible or dazzling at -5 degrees or -45 degrees.

(6) Pencil hardness evaluation Pencil hardness evaluation described in JIS K5400 was performed as an index of scratch resistance. After conditioning the anti-reflection film at a temperature of 25 ° C. and a humidity of 60% RH for 2 hours, using a 3H test pencil specified in JIS S 6006, with a load of 1 kg. Not allowed at all
Δ: One or two scratches in the evaluation of n = 5
X: 3 or more scratches in the evaluation of n = 5

(7) Curling degree The optical film sample was cut into a size of 20 cm × 20 cm, and placed on a horizontal desk in an environment of 25 ° C. and 60% RH with the surfaces with the four raised corners facing upward. After 24 hours, the lifting distance from the desk surface at each of the four corners was measured with a ruler, and the average of the four corners was taken. The average values were evaluated according to the following criteria.
◎: Less than 5mm ○: Less than 5-10mm ○ △: Less than 10-20mm △: Less than 20-40mm ×: 40mm or more

(8) Brittleness One end (A) in the longitudinal direction of the sample of 35 mm × 250 mm is fixed in the vicinity of a gap of a flat plate jig having a gap of 7 mm width, and the other end (B) is passed through the gap and taken out to the other side. A method was used in which a sample that protruded to the far side was looped into a hairpin shape, and the tip (B) was then pulled out from the far side to the near side through the same gap. The surface on which the hard coat layer was applied was arranged on the outside. After pulling out, the sample was checked for cracks, and the distance from the end of the fixed side (A) to the point where cracks began to appear was measured and evaluated according to the following criteria. The shorter the distance, the smaller the radius of curvature when cracking occurs, indicating that cracking is less likely.
◎: Less than 20 mm ○: Less than 20-30 mm ○ △: Less than 30-50 mm △: Less than 50-80 mm ×: 80 mm or more

From the results shown in Table 5, the following is clear.
The optical film of the present invention has desirable optical performance (average reflectance, haze, image sharpness, darkening, antiglare) as antireflection, and the coating film has high hardness, such as a pencil. The scratch resistance is also good, the curl is small, and the brittleness is excellent.
These optical films, which are excellent in the overall performance of optical films, have been revealed for the first time by the present invention.

[Example 2]
[Production and Evaluation of Optical Film Samples 201 to 217]
(1) Application of transparent hard coat layer
A triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Film Co., Ltd., refractive index 1.48) having a thickness of 80 μm is unwound in a roll form, and the coating liquid for hard coat layer is listed in Table 6 respectively. Apply the die coating method using the slot die as described above under the condition of a conveyance speed of 30 m / min, apply the coating solution for hard coat layer, dry at 60 ° C. for 150 seconds, and further under nitrogen purge Using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) of 160 W / cm, ultraviolet rays having an illuminance of 400 mW / cm ² and an irradiation amount of 250 mJ / cm ² were irradiated to form a transparent hard coat layer. The thickness of the support and the content of the transparent hard coat layer are as shown in Table 6.

On the surface coated with the transparent hard coat layer, the coating solution for the low refractive index layer is formed by the die coating method using the slot die so as to have the configuration shown in Table 6, respectively. After being dried at 120 ° C. for 75 seconds and further heated for 10 minutes, using a 240 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) under a nitrogen purge, an illuminance of 400 mW / cm ² , An ultraviolet ray with an irradiation amount of 240 mJ / cm ² was irradiated to form a low refractive index layer having a thickness of 100 nm and wound up.

(Preparation of optical film sample)
An optical film sample was prepared by a combination of layers as shown in Table 6 below by the above method. In Table 6, the layers were coated on the support in order from the coating layer described on the left side.

(Saponification of optical film)
After coating, samples 201 to 228 were subjected to the same saponification treatment as in Example 1.
In this way, saponified optical films (invention samples 201 to 228) were produced.

(Evaluation of optical film)
About these obtained optical film samples, the same evaluation as the said Example 1 was performed. The results are shown in Table 7.

From the results shown in Table 7, the following is clear.
Also in the optical film having the transparent hard coat layer of Example 2, as in Example 1, the optical film of the present invention has optical performance as an antireflection (average reflectance, haze, image sharpness, blackening property, The antiglare property is in a desirable range, the coating film has high hardness, scratch resistance such as a pencil is good, curl is small, and brittleness is excellent.

[Example 3]
About coating liquid J-1 to J-16 for light diffusion layers, it apply | coats so that it may become a thickness of 6 micrometers on a triacetyl-cellulose film (TAC-TD80U, Fujifilm Co., Ltd.) using a wire bar. Then, curing was performed under the same drying and UV conditions as in the preparation of the hard coat layer of Example 1. The coated surface of the cured sample was visually evaluated for surface condition and compared with a sample having a layer thickness of 6 μm among the samples of Example 1.
As a result, the surface shape of the surface coated with the hard coat layer of the sample produced by the die coating method of Example 1 was good. Furthermore, the surface shape of the sample coated with the coating liquids J-1 and J-2 performed in Example 3 was good. These results indicate that the die coating method is excellent as a method for applying the coating liquid according to the present invention.

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

[Example 5]
The 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 respective films of the samples of the present invention in Example 1 and Example 2 were attached, and the liquid crystal cell side of the polarizing plate on the backlight side When using an optical compensation film (Wide View Film Ace, manufactured by Fuji Film Co., Ltd.) as a protective film, it has excellent contrast in a bright room, very wide viewing angles in the vertical and horizontal directions, and extremely excellent visibility. A liquid crystal display device with high display quality was obtained.
In addition, the sample of the present invention has a scattered light intensity of 30 ° with respect to an emission angle of 0 ° of 0.06%, and this light diffusibility improves particularly the downward viewing angle and the yellowness in the left-right direction. It was a very good liquid crystal display device.

[Example 6]
When each film of the sample of the present invention in Example 1 was bonded to the glass plate on the surface of the organic EL display device via an adhesive, reflection on the glass surface was suppressed, and a display device with high visibility was obtained. It was.

[Example 7]
A polarizing plate with a single-sided optical film was prepared using each film of the sample of the present invention in Example 1 and Example 2, and a λ / 4 plate was placed on the opposite side of the polarizing plate having the optical functional film. Pasting and pasting to the glass plate on the surface of the organic EL display device so that the low refractive index layer side becomes the outermost surface, the surface reflection and reflection from the inside of the surface glass are cut, and display with extremely high visibility was gotten.

It is sectional drawing of the slot die coater suitable for this invention. (A) is sectional drawing of the slot die suitable for this invention, (B) is sectional drawing of the conventional slot die. 1 is a perspective view of a slot die and peripheral devices suitable for the present invention. FIG. It is sectional drawing of the web of a coating device suitable for this invention, and a pressure reduction chamber.

Explanation of symbols

10 Coater 11 Backup roll 12 Web 13 Slot die 14 Coating liquid 15, 32 Pocket 16, 33 Slot 16a Slot opening 17 Tip lip 18 Land 18a, 31a Upstream lip land 18b, 31b Downstream lip land 30 Conventional slot die 32 Pocket 33 Slot 40 Depressurization chamber 40a Back plate 40b Side plate IUP Length of upstream lip land ILO Length of downstream lip land

Claims (8)

An optical film having at least one hard coat layer on a transparent support, wherein at least one of the hard coat layers is
(A) a bifunctional (meth) acrylate compound having a molecular weight in the range of 210 to 500 and having at least one of an alicyclic ring, an aromatic ring and a heterocyclic structure in the molecule;
(B) a polyfunctional acrylate compound having three or more (meth) acryloyl groups,
(C) a photopolymerization initiator,
An optical film which is a layer formed from a composition containing   The optical film according to claim 1, wherein the hard coat layer is a light diffusing hard coat layer containing translucent particles.   The hard coat layer is composed of at least two hard coat layers of a light diffusing hard coat layer containing translucent particles and a transparent hard coat layer not containing translucent particles, and the transparent hard coat layer The optical film according to claim 1, wherein the optical film is a layer formed from a composition containing the compounds of (A), (B), and (C).   The thickness of the light diffusing hard coat layer is 0.03 to 0.20 times the thickness of the transparent support, and the average particle size of the light transmissive particles is the thickness of the light diffusing hard coat layer. The optical film according to claim 2, wherein the optical film has a ratio of 0.2 to 0.8 times.   An antireflection film comprising a layer having a refractive index lower than that of the transparent support on the hard coat layer or the light diffusing hard coat layer of the optical film according to claim 1.   A polarizing plate having a pair of protective films and a polarizing film between the pair of protective films, wherein at least one of the protective films is the optical film according to claim 1, or claim 5. A polarizing plate, which is the antireflection film described in 1.   It is a display apparatus which has the optical film in any one of Claims 1-4, the antireflection film of Claim 5, or the polarizing plate of Claim 6, Comprising: This optical film, an antireflection film, or A display device, wherein a hard coat layer, a light diffusible hard coat layer, or a low refractive index layer of a polarizing plate is disposed on the viewing side. A method for producing an optical film having at least one hard coat layer or at least one light diffusing hard coat layer on a transparent support, wherein the at least one hard coat layer or at least one layer Light diffusing hard coat layer
(A) a bifunctional (meth) acrylate compound having a molecular weight in the range of 210 to 500 and having at least one of an alicyclic ring, an aromatic ring and a heterocyclic structure in the molecule;
(B) a polyfunctional acrylate compound having three or more (meth) acryloyl groups,
(C) a photopolymerization initiator,
And a coating solution having a viscosity in the range of 10 to 200 mPa · s is applied by a die coating method and cured, and the method for producing an optical film is characterized.

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