JP2006018062A - Antireflection film, polarizing plate, and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antireflection film which hardly causes coloring unevenness, has excellent visibility and has improved black display, to provide a polarization plate having the antireflection film, and to provide a display device having the polarization plate. <P>SOLUTION: The antireflection film is made by laminating antireflection layers of a membrane M (refractive index 1.55 to 1.75, membrane thickness 80 to 120 nm), a membrane H (refractive index 1.75 to 2.4, membrane thickness 30 to 70 nm) and a membrane L (refractive index 1.3 to 1.45, membrne thickness 70 to 130 nm) in order on one side surface of a plastic base material having a refractive index of 1.45 to 1.55 at wavelength 550 nm. Therein, material colors in reflection and transmission under a CIE standard illuminant C light source are expressed in the CIELAB color system as follow; for the material color according to reflection, L<SP>*</SP>value is ≤15, a<SP>*</SP>value is 0.5 to 5, b<SP>*</SP>value is -20 to 5 and, for the material color according to transmission, L<SP>*</SP>value is ≥92, a<SP>*</SP>value is -3 to 3, b<SP>*</SP>value is -3 to 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an antireflection film, a polarizing plate, and a display device, and more particularly to an antireflection film, a polarizing plate, and a display device that have excellent visibility and improved black display.

  Conventionally, an antireflection technique for reducing surface reflection has been proposed mainly for the fields of optical lenses, CRTs, computers, word processing liquid crystal image display devices, and the like in order to improve transmittance and contrast and reduce reflection. As an antireflection technique, it is effective to reduce reflection of light at the interface between the laminated body and the air by laminating several layers having appropriate values of refractive index and optical film thickness as the optical interference layer.

Such an antireflection layer is formed by laminating TiO ₂ , ZrO ₂ , Ta ₂ O _5, etc. as a high refractive index material, and SiO ₂ , MgF _2, etc. as low refractive index materials. The prevention layer can be manufactured by a dry film forming method and a coating type film forming method.

  As a dry film forming method, there are a sputtering method, a vacuum deposition method, an ion plating method, a CVD method or a PVD method. From the viewpoint of optical function, the dry film forming method is superior, but the coating film forming method is suitable. Has the advantage of being easy to manufacture and inexpensive.

  As a coating type film forming method, a metal alkoxide represented by titanium alkoxide or silane alkoxide is applied to the surface of a support (hereinafter also referred to as a base material or a base film), dried and heated to form a metal oxide film. The method of forming is performed.

  By the way, in an image display device such as a liquid crystal display device (LCD), a plasma display panel (PDP), an electroluminescence display (ELD), a cathode ray tube display device (CRT), a fluorescent display tube, or a field emission display, an image display is performed. It is important to improve the visibility.

  In general, in order to improve the visibility of the antireflection film, the antireflection film is designed to have a bluish color and a reddish color so as to reduce the reflectance of the green color that most affects the visibility. However, when there is uneven thickness of the antireflection film, the color may be changed from red purple to blue purple depending on the reflected light, and on the contrary, the display quality may be lowered.

  In addition, depending on the design of the low-reflection laminate (antireflection film) and the components such as materials, the uniformity of color developability may be poor, or coloring unevenness different from the display color may be seen especially when reproducing black or high density images. There was a desire for improvement.

In view of this problem, a technique for defining the reflectance of reflected light from the display and the L ^* a ^* b ^* value has been disclosed (see, for example, Patent Document 1). It has been found that it is difficult to make the light color uniformity uniform, and when an antistatic agent or the like is added for the purpose of improving the handleability of the film, it becomes difficult to adjust the color tone by coloring the antistatic agent. .
JP 2003-121606 A

  An object of the present invention is to provide an antireflection film, a polarizing plate, and a display device in which coloring unevenness is not conspicuous and excellent in visibility and black display is improved.

  The above object of the present invention is achieved by the following configurations.

(Claim 1)
On at least one surface of a plastic substrate having a refractive index of 1.45 to 1.55 at a wavelength of 550 nm, film M (refractive index 1.55 to 1.75, film thickness 80 to 120 nm), film H (refractive An antireflection film in which an antireflection film is laminated in the order of a rate of 1.75 to 2.4 and a film thickness of 30 to 70 nm) and a film L (refractive index of 1.3 to 1.45, film thickness of 70 to 130 nm). An antireflective film characterized in that the object color in reflection and transmission under a standard illuminant C light source for CIE colorimetry is CIELAB color system and the values of L ^* , a ^* and b ^* are in the following ranges.

(I) Object color by reflection: L ^* value 15 or less
a ^* Value in the range of 0.5-5
b ^* value range -20~5 (ii) object color by transmission: L ^* value 92 or more
a ^* Value in the range of 3-3
b ^* value range of -3 to 3 (Claim 2)
2. The reflection according to claim 1, wherein the object color in reflection and transmission under the CIE colorimetric standard illuminant C light source is CIELAB color system, and the values of L ^* , a ^* , and b ^* are in the following ranges. Prevention film.

(Iii) Object color due to reflection: L ^* value range of 1-8
a ^* value range of 0.6-3
b ^* value range of -17 to 3 (iv) object color by transmission: L ^* value range of 92 to 99.9
a ^* value -1.5 to 1.5 range
range of b ^* value -1.5～1.5 (claim 3)
The object color in transmission under the standard illuminant C light source for CIE colorimetry of the plastic substrate is CIELAB color system, and the values of L ^* , a ^* , b ^* are in the following ranges: 2. The antireflection film according to 2.

(V) Object color by transmission: L ^* value range of 96.9 to 97.4
a ^* value -0.3 to -0.1 range
b ^* value in the range of 0.4 to 1.0 (Claim 4)
The antireflection film according to claim 1, wherein the film M or the film H is a film containing conductive fine particles.

(Claim 5)
The antireflection film according to claim 4, wherein the conductive fine particles are ITO or metal-doped zinc oxide.

(Claim 6)
6. The product dx is in the range of 30 to 80, where d (nm) is the film thickness of the antireflection film and x is the content ratio of the conductive fine particles. 2. The antireflection film according to item 1.

(Claim 7)
The antireflection film according to claim 1, wherein the plastic substrate contains an ultraviolet absorber.

(Claim 8)
The antireflection film according to claim 7, wherein the ultraviolet absorber is a benzotriazole ultraviolet absorber.

(Claim 9)
The antireflection film according to claim 7 or 8, wherein the ultraviolet absorber is two or more kinds of benzotriazole ultraviolet absorbers.

(Claim 10)
The antireflection film according to claim 1, further comprising a hard coat layer on the plastic substrate.

(Claim 11)
The said plastic base material is a cellulose-ester film, and width is 1.4 m or more, The antireflection film of any one of Claims 1-10 characterized by the above-mentioned.

(Claim 12)
A polarizing plate comprising the antireflection film according to claim 1.

(Claim 13)
A display device comprising the antireflection film according to claim 1.

(Claim 14)
A display device comprising the polarizing plate according to claim 12.

  According to the present invention, it is possible to provide an antireflection film, a polarizing plate, and a display device in which coloring unevenness is not conspicuous, the visibility is excellent, and the black display is improved.

  The best mode for carrying out the present invention will be described in detail below, but the present invention is not limited thereto.

As a result of diligent research, the present inventor made the coloring unevenness conspicuous by setting the L ^* a ^* b ^* value represented by the CIELAB color system of the object color in reflection and transmission of the antireflection film to a value within a certain range. The present inventors have found that an antireflection film having excellent visibility and improved black display can be obtained.

  It is known that coloring unevenness mainly due to film thickness unevenness of the antireflection layer can be improved by suppressing the film thickness unevenness, but particularly in the coating film forming method, there are various coating processes and drying processes. Due to the factors, it is difficult to completely remove the film thickness unevenness. Therefore, it is important to obtain an antireflection film that does not feel visually uneven even if film thickness unevenness exists.

  By producing an antireflection film in which the color tone of the object color in reflection and transmission is controlled by the configuration of the present invention, even if film thickness unevenness exists, it is possible to obtain an antireflection film that does not substantially feel unevenness visually. It is up to the present invention that the present invention can be found. In particular, the effect of the present invention is effective with a wide antireflection film.

  Furthermore, the color tone of the object color in reflection and transmission can be controlled more preferably when the antireflection film M or the film H is a film containing conductive fine particles, and the conductive fine particles are ITO or metal-doped zinc oxide. I found out.

  Further, it has been found that when the plastic substrate contains an ultraviolet absorber and the ultraviolet absorber is a benzotriazole-based ultraviolet absorber, it can be more preferably controlled.

The L ^* a ^* b ^* value of the present invention is a value measured according to CIELAB described in JIS Z 8729, measured under illumination conditions in a standard illuminant C light source for CIE colorimetry specified in JIS Z 8720. In the reflection spectrum measurement, the specular reflection component of the sample to be measured is measured. From the interval of the measurement area measurement point, preferably 3mm ² ~50mm ^2. L ^* a ^* b ^* values are two-degree field, determined as C source.

  The sample to be measured is processed to measure an accurate reflection spectrum. In order to prevent the light that has passed through the antireflection film from being reflected by the measurement table or the like in the sample processing, the surface of the sample support on which the antireflection layer is not provided is measured at a transmittance of 380 nm to 730 nm. Is colored black so that it is less than 10%, preferably less than 1%. Further, a sample is placed on a black sample table and measured.

The L ^* a ^* b ^* value of the object color in the transmission is calculated from the spectral transmittance obtained by the antireflection film sample set in the spectrophotometer every 5 nm in the wavelength range of 380 to 780 nm. In the formula for calculating the L ^* a ^* b ^* value of JIS Z 8729, P (λ) is the spectral distribution of the standard illuminant C light source for CIE colorimetry specified in JIS Z 8720, and y (λ) is the double field of view X Is a color matching function based on the Y, Z, and Z systems. Spectral transmittance τ (λ) can be measured using, for example, Hitachi U-3310 type, and an L ^* a ^* b ^* value obtained from tristimulus values in a double-view XYZ system according to the method of JIS Z 8729 is calculated. .

Preferable ranges of the values of L ^* , a ^* , and b ^* are as follows.

(I) Object color by reflection: L ^* value 15 or less
a ^* Value in the range of 0.5-5
b ^* value range of -20 to 5 (ii) object color by transmission: L ^* value 92 or more
a ^* Value in the range of 3-3
b ^* value range of −3 to 3 a ^* value <0.5 is not preferable because cyan is strong, and a ^* value> 5 is red. When b ^* value <−20, blue is strong, and when b ^* value> 5, yellow is strong.

More preferably (iii) Object color by reflection: L ^* value range of 1-8
a ^* value range of 0.6-3
b ^* value range of -17 to 3 (iv) object color by transmission: L ^* value range of 92 to 99.9
a ^* value -1.5 to 1.5 range
The b ^* value is preferably in the range of -1.5 to 1.5 as the color tone of the antireflection film that makes coloring unevenness inconspicuous.

  The reflectance of the antireflection film is preferably 1% or less in the range of 500 nm to 650 nm.

  The antireflection film in which the antireflection film of the present invention is laminated refers to a film M (refractive index 1.55 to 1.75, film thickness 80 to 120 nm), film H (from the support side to at least one surface of the support. An antireflection film is laminated in the order of refractive index 1.75 to 2.4, film thickness 30 to 70 nm) and film L (refractive index 1.3 to 1.45, film thickness 70 to 130 nm). To do.

  In general, the antireflection film comprises a plurality of antireflection layers. The antireflection film has a hard coat layer, which will be described later, on a transparent base material, if necessary, and has a refractive index, a film thickness, the number of layers, and a layer order so that the reflectance decreases due to optical interference. Etc. are taken into consideration. The antireflection layer is usually composed of a combination of a high refractive index layer having a higher refractive index than that of the substrate and a low refractive index layer having a lower refractive index than that of the substrate. Examples of configurations include two layers of a high refractive index layer / low refractive index layer from the base material side, and three layers having different refractive indices, a medium refractive index layer (having a higher refractive index than the base material or the hard coat layer). , A layer having a refractive index lower than that of a high refractive index layer) / a layer having a high refractive index / a layer having a low refractive index, and the like. The antireflective film of the present invention is a medium refractive index layer (film M) / high refractive index layer (film H) on a substrate having a hard coat layer, among others, due to optical properties, durability, cost, productivity, and the like. / Low refractive index layer (film L) is applied in this order.

  The example of the preferable layer structure of the antireflection film of this invention is shown below.

Base film / Hard coat layer / Medium refractive index layer / High refractive index layer / Low refractive index layer Base film / Anti-glare layer / Medium refractive index layer / High refractive index layer / Low refractive index layer Base film / Antistatic Layer / hard coat layer / medium refractive index layer / high refractive index layer / low refractive index layer antistatic layer / base film / hard coat layer / medium refractive index layer / high refractive index layer / low refractive index layer base film / Antistatic layer / Antiglare layer / Medium refractive index layer / High refractive index layer / Low refractive index layer Antistatic layer / Base film / Antiglare layer / Medium refractive index layer / High refractive index layer / Low refractive index layer Optical interference As long as the reflectance can be reduced by the above, it is not particularly limited to these layer configurations. Further, the antistatic layer is a conductive polymer particles or metal oxide particles (e.g., SnO _2, ITO, is Zn1-xMxO (M metal or halogen element)) is preferably a layer containing, coating or atmospheric plasma treatment Etc. can be provided. The antistatic layer can also serve as a hard coat layer or a medium to high refractive index layer, and it is particularly preferable in terms of performance and production that it also serves as a medium to high refractive index layer.

In the present invention, at least one layer of the optical interference layer is formed by applying and drying a coating solution containing a monomer, oligomer or hydrolyzate of an organotitanium compound represented by Ti (OR ¹ ) ₄ . A layer having a refractive index of 1.55 to 2.4 is preferable.

R ¹ is preferably an aliphatic hydrocarbon group having 1 to 8 carbon atoms, preferably an aliphatic hydrocarbon group having 1 to 4 carbon atoms. In addition, the monomer, oligomer or hydrolyzate of the organic titanium compound reacts like -Ti-O-Ti- when the alkoxide group is hydrolyzed to form a crosslinked structure, thereby forming a cured layer.

As monomers and oligomers of organic titanium compounds, Ti (OCH ₃ ) ₄ , Ti (OC ₂ H ₅ ) ₄ , Ti (On-C ₃ H ₇ ) ₄ , Ti (Oi-C ₃ H ₇ ) ₄ , Ti (On-C ₄ H ₉ ) ₄ , Ti (On-C ₃ H ₇ ) ₄ di- to 10-mer, Ti (O-i-C ₃ H ₇ ) ₄ 2 to 10 mer, 2-10 mers etc. _{Ti (O-n-C 4} H 9) 4 and the like. These may be used alone or in combination of two or more. Of these _{Ti (O-n-C 3} H 7) 4, Ti (O-i-C 3 H 7) 4, Ti (O-n-C 4 H 9) 4, Ti (O-n-C 3 H 7 ) ₄ to 10-mer and Ti (On-C ₄ H ₉ ) ₄ to 10-mer are particularly preferable.

  The monomer, oligomer or hydrolyzate of the organic titanium compound needs to occupy 50.0 to 98.0% by mass in the solid content contained in the coating solution. If this range is exceeded, the refractive index will not be in the desired range, and the low reflection effect cannot be fully exhibited. The solid content ratio is more preferably 50 to 90% by mass, and further preferably 55 to 90% by mass. In addition, it is also preferable to add a polymer of an organic titanium compound (a product obtained by previously hydrolyzing an organic titanium compound to be crosslinked) to the coating composition.

  Further, in the present invention, the coating liquid contains the above-mentioned organotitanium compound monomer, oligomer part or complete hydrolyzate, but the organotitanium compound monomer and oligomer are self-condensed, crosslinked and network-bonded. is there. Catalysts and curing agents can be used to accelerate the reaction, including metal chelate compounds, organometallic compounds such as organic carboxylates, organosilicon compounds having amino groups, and acid generation by light. Agent (photoacid generator). Of these catalysts or curing agents, an aluminum chelate compound and a photoacid generator are particularly preferred. Examples of aluminum chelate compounds are ethyl acetoacetate aluminum diisopropylate, aluminum trisethyl acetoacetate, alkyl acetoacetate aluminum diisopropylate, aluminum monoacetylacetonate bisethylacetoacetate, aluminum trisacetylacetonate, etc. Examples of the acid generator include benzyltriphenylphosphonium hexafluorophosphate, other phosphonium salts, and triphenylphosphonium hexafluorophosphate salts.

  In the middle to high refractive index layer containing the organic titanium compound, an alcohol-soluble acrylic resin is particularly preferably used as a binder, whereby a high and low refractive index layer can be obtained with little film thickness unevenness. Specifically, an alkyl (meth) acrylate polymer or an alkyl (meth) acrylate copolymer, for example, a copolymer such as n-butyl methacrylate, isobutyl methacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, is preferably used. The copolymer component is not limited to these. Commercially available products include Dianal BR-50, BR-51, BR-52, BR-60, BR-64, BR-65, BR-70, BR-73, BR-75, BR-76, BR-77. , BR-79, BR-80, BR-82, BR-83, BR-85, BR-87, BR-88, BR-89, BR-90, BR-93, BR-95, BR-96, BR -100, BR-101, BR-102, BR-105, BR-107, BR-108, BR-112, BR-113, BR-115, BR-116, BR-117, BR-118 (above, Mitsubishi Can be used. These monomer components can also be added as a binder for the medium to high refractive index layer.

  The film M or film H forming the middle to high refractive index layer of the present invention is preferably a film containing conductive fine particles, and the conductive fine particles are preferably conductive metal oxide fine particles.

In the conductive metal oxide fine particles, the volume resistivity of the metal oxide powder is 10 ⁷ Ω · cm or less, and preferably 10 ⁵ Ω · cm or less. Examples of preferable metal oxides include ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , In ₂ O ₃ , SiO ₂ , MgO, BaO, MoO ₂ , V ₂ O ₅ , and complex oxides thereof. Particularly preferred are ZnO, In ₂ O ₃ , TiO ₂ and SnO ₂ . Examples containing different metal atoms, for example the addition Al, or In to ZnO, addition Nb, or Ta for TiO _2, also for the SnO _2, Sb, Nb, halogen elements etc. Is effective. Particularly preferred are ITO (indium tin oxide) and metal-doped ZnO. The amount of these different atoms added is preferably in the range of 0.01 to 25 mol%, particularly preferably in the range of 0.1 to 15 mol%. Most preferably, it is ITO (indium tin oxide).

  The preferable addition amount of tin in ITO is preferably 4 to 6% by mass, more preferably 4.5 to 5.5% by mass with respect to the total of indium and tin. Since the color tone varies depending on the amount of tin mixed and the crystallinity of the ITO itself, the optimum amount is adjusted so that the color tone can be adjusted within the scope of the present invention in combination with the amount and type of UV absorbers described later. Just decide.

  The ITO content in the antireflection film is such that the product dx is in the range of 30 to 80, where d (nm) is the film thickness of the antireflection film and x is the content ratio of the conductive fine particles in the film. The amount is preferably contained, and more preferably in the range of 40 to 70. Here, the content ratio x is represented by the following formula.

Formula x = (mass of conductive fine particles / total mass of film including conductive fine particles)
Moreover, an ionic polymer compound can also be used together as another antistatic agent in the middle to high refractive index layer.

  Examples of the ionic polymer compound include anionic polymer compounds such as those described in JP-B-49-23828, JP-A-49-23827, and JP-A-47-28937; JP-B-55-734, JP-A-50-54672 Ionene type polymers having a dissociating group in the main chain, as seen in JP-B Nos. 59-14735, 57-18175, 57-18176, 57-56059, etc .; No. 57-15376, No. 53-45231, No. 55-145783, No. 55-65950, No. 55-67746, No. 57-11342, No. 57-19735, No. 58-56858. No., JP-A 61-27853, 62-9346, and a cationic pendant type poly having a cationic dissociation group in the side chain. Over; and the like can be mentioned.

The surface specific resistance value of the antireflection film having a medium to high refractive index layer according to the present invention is preferably adjusted to 10 ¹¹ Ω / □ (25 ° C., 55% RH) or less, more preferably 10 ^10. Ω / □ (25 ° C., 55% RH) or less, particularly preferably 10 ⁹ Ω / □ (25 ° C., 55% RH) or less.

  Here, the surface specific resistance value is measured using a terraohm meter model VE-30 manufactured by Kawaguchi Electric Co., Ltd. for 24 hours under conditions of 25 ° C. and 55% RH.

  Solvents used in the coating solution for coating the medium to high refractive index layer according to the present invention are diacetone alcohol, methanol, ethanol, propyl alcohol, isopropyl alcohol, n-butanol, diacetone alcohol, methyl acetate, acetic acid. Ethyl, acetone, methyl acetoacetate, methylene chloride, acetone, methyl isobutyl ketone (MIBK), methyl ethyl ketone (MEK), cyclohexanone, ethyl formate, 1,3-dioxolane, 1,4-dioxane, ethylene glycol methyl ether, propylene glycol monomethyl Ether (PGME), ethylene glycol methyl ether acetate, 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoro-1-propanol, isopropyl alcohol, 1,3-difluoro 2-propanol, 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol, 1,1,1,3,3,3-hexafluoro-2-propanol, 2,2, 3,3,3-pentafluoro-1-propanol and the like can be mentioned, and single or a mixture of two or more can be used.

  Moreover, the said solvent can be preferably used also as a dispersion | distribution solvent of the metal oxide of this invention.

  The coating solution preferably contains 0.1 to 40.0 mass% of fine particles having an average particle size of 0.1 μm or less containing titanium oxide in a solid content ratio. 0.001-0.1 μm fine particles are more preferable. Thereby, film | membrane intensity | strength can be improved and it becomes difficult to get a damage | wound. In addition, the effect of preventing blocking can be obtained.

  The optical interference layer containing these titanium oxides is mainly used for a high refractive index layer, but can also be used as a middle refractive index layer by adjusting additives or the like.

In the present invention, Si (OR ² ) ₄ , Si—X ₄ , R ³ is formed on the middle to high refractive index layer formed by using the monomer, oligomer or hydrolyzate of the organic titanium compound described above. Refractive index formed by applying and drying a coating solution containing a monomer, oligomer or mixture of organosilicon compounds represented by any one of —Si (OR ₂ ) ₃ and R ³ —Si—X ₃ It is preferable that a low refractive index layer having a thickness of 1.3 to less than 1.45 is laminated.

Examples of preferable organosilicon compounds include tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, and the like. An oligomer is obtained. The hydrolysis reaction can be carried out by a known method. For example, a predetermined amount of water is added to the tetraalkoxysilane, and the by-product alcohol is distilled off in the presence of an acid catalyst. React with. By this reaction, the alkoxysilane is hydrolyzed, followed by a condensation reaction, and a liquid silicate oligomer having two or more hydroxyl groups (usually the average degree of polymerization is 2 to 8, preferably 3 to 6) as a hydrolyzate. Can be obtained. The degree of hydrolysis can be appropriately adjusted depending on the amount of water used, but is 40 to 90%, preferably 60 to 80%. Here, as for the degree of hydrolysis, in the hydrolyzable group, that is, tetraalkoxysilane, the theoretical amount of water necessary to hydrolyze all the alkoxy groups, that is, half the number of alkoxy groups, was added. Time is 100% hydrolysis rate,
Hydrolysis rate (%) = (actual amount of added water / theoretical amount of hydrolysis) × 100
As required.

  The silicate oligomer thus obtained usually contains about 2 to 10% of monomers. It can be used in the monomer state, in the oligomer state, or mixed with the monomer and oligomer, but if the monomer is contained, it lacks storage stability and thickens during storage, forming a film Therefore, it is preferable to remove the monomer by flash distillation or vacuum distillation so that the monomer content is 1% by mass or less, preferably 0.3% by mass or less.

  In the present invention, a partial hydrolyzate obtained by adding a catalyst and water to tetraalkoxysilane as described above is used, but a complete hydrolyzate is preferably used. A hydrolyzate cured by a method such as adding a solvent to the hydrolyzate and then adding the following curing catalyst and water is obtained. As such a solvent, it is preferable to use one or two kinds of methanol and ethanol because they are inexpensive and have excellent properties and excellent hardness. Although isopropanol, n-butanol, isobutanol, octanol, and the like can be used, the hardness of the obtained film tends to be low. The amount of the solvent is 50 to 400 parts by mass, preferably 100 to 250 parts by mass with respect to 100 parts by mass of the partial hydrolyzate.

  Examples of the curing catalyst include acids, alkalis, organic metals, metal alkoxides and the like, but acids, particularly organic acids having a sulfonyl group or a carboxyl group are preferably used. For example, acetic acid, polyacrylic acid, benzenesulfonic acid, p-toluenesulfonic acid, methylsulfonic acid and the like are used. The organic acid is more preferably a compound having a hydroxyl group and a carboxyl group in one molecule. For example, a hydroxydicarboxylic acid such as citric acid or tartaric acid is used. The organic acid is more preferably a water-soluble acid. For example, in addition to the citric acid and tartaric acid, levulinic acid, formic acid, propionic acid, malic acid, succinic acid, methyl succinic acid, fumaric acid, oxaloacetic acid, pyruvin. Acid, 2-oxoglutaric acid, glycolic acid, D-glyceric acid, D-gluconic acid, malonic acid, maleic acid, oxalic acid, isocitric acid, lactic acid and the like are preferably used. Also, benzoic acid, hydroxybenzoic acid, atorvaic acid and the like can be used as appropriate.

  By using the above-mentioned organic acids, not only can the piping corrosion and safety concerns during production due to the use of inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid, hypochlorous acid, and boric acid be eliminated, but also during hydrolysis. A stable hydrolyzate can be obtained without causing gelation. The addition amount is 0.1 to 10 parts by mass, preferably 0.2 to 5 parts by mass with respect to 100 parts by mass of the partial hydrolyzate. Further, the amount of water added may be more than the amount that the partial hydrolyzate can theoretically hydrolyze to 100%, and the equivalent amount of 100 to 300%, preferably the equivalent amount of 100 to 200%, should be added. .

  The coating composition for the low refractive index layer thus obtained is extremely stable, and 1 hour, 6 hours, 12 hours, 1 day, 3 days, and 7 days have elapsed since the start of hydrolysis. Can also be used.

  Further, in the present invention, the aging step sufficiently proceeds the hydrolysis and condensation of the organosilicon compound, and the resulting film has excellent properties. For the aging, the oligomer liquid may be allowed to stand, and the standing time is a time for which the above-described crosslinking proceeds to a degree sufficient to obtain desired film characteristics. Specifically, depending on the type of catalyst used, hydrochloric acid or nitric acid is sufficient for 1 hour or more at room temperature, and for maleic acid or acetic acid, several hours or more, 8 hours to 1 week is sufficient, and usually around 3 days. The ripening temperature affects the ripening time, and it may be better to take a means of heating to around 20 ° C. in extremely cold regions. In general, ripening progresses quickly at high temperatures, but when heated to 100 ° C. or higher, gelation occurs. Therefore, heating to 50 to 60 ° C. at best is appropriate.

  In addition to the above, the silicate oligomer may be a modified product modified with an organic compound (monomer, oligomer, polymer) having a functional group such as an epoxy group, an amino group, an isocyanate group, or a carboxyl group. , Alone or in combination with the above silicate oligomer.

Thus, silicate oligomers of organosilicon compounds represented by Si (OR ² ) ₄ , Si—X ₄ , R ³ —Si (OR ₂ ) ₃ and R ³ —Si—X ₃ are obtained. SiO ₂ content in the silicate oligomer from 1 to 100%, preferably 10 to 99%. If the SiO ₂ content is less than 1%, the durability is not improved and the effect is not exhibited.

  For the low refractive index layer, an alcohol-soluble acrylic resin or an epoxy-based active energy ray reactive compound is preferably used.

  The low refractive index layer having a very thin film has insufficient hardness, and the layer surface is vulnerable to scratches or scratches. In such a case, generally, an active energy ray irradiation crosslinkable ethylenically unsaturated compound that easily forms a cured film is generally contained in the layer. Since the film is easily affected by oxygen in the air and the film thickness is thin, the polymerization of the ethylenically unsaturated compound is easily inhibited, and this method cannot provide a tough low refractive index layer.

  Hardness is insufficient, and the low-refractive index layer that is vulnerable to scratches and scratches contains an epoxy-based active energy ray-reactive compound. By irradiating with active energy rays, the hardness is high and it is strong against scratches and scratches. It is preferable to form a low refractive index layer.

  Epoxy active energy ray-reactive compounds are polymerized quickly because they are not easily inhibited by oxygen, and have excellent active energy capable of forming a high hardness and tough coating even when the film thickness is as thin as 50 to 200 nm. It is a linear reactive compound. The epoxy-based active energy ray-reactive compound is a compound having two or more epoxy groups in the molecule.

  In the present invention, silicon oxide fine particles can be contained in the low refractive index layer. It is preferable to include silicon oxide fine particles having a particle size of 0.1 μm or less. In particular, silicon oxide fine particles whose surface is modified with an alkyl group are preferably used. For example, silicon oxide fine particles whose surface is modified with a methyl group are commercially available as Aerosil R972 and R972V (manufactured by Nippon Aerosil Co., Ltd.). Preferably it can be added. In addition, it is possible to use silicon oxide fine particles whose surface described in JP-A-2001-2799 is substituted with an alkyl group, and after the hydrolysis of the silicate oligomer, the surface is treated with an alkylsilane coupling agent. But it can be easily obtained. As an addition amount, it is preferable to add so that it may become the range of 0.1-40 mass% in the solid content ratio in a low-refractive-index layer.

  Solvents used in the coating solution for coating the optical interference layer of the present invention are alcohols such as methanol, ethanol, 1-propanol, 2-propanol and butanol; ketones such as acetone, methyl ethyl ketone and cyclohexanone; benzene, Aromatic hydrocarbons such as toluene and xylene; glycols such as ethylene glycol, propylene glycol and hexylene glycol; ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, diethyl cellosolve, diethyl carbitol, propylene Glycol ethers such as glycol monomethyl ether; N-methylpyrrolidone, dimethylformamide, methyl lactate, ethyl lactate, water and the like can be mentioned, and these can be used alone or in admixture of two or more.

  In particular, by using at least one solvent having a boiling point at 1 atm of 120 to 180 ° C. and a vapor pressure at 20 ° C. of 2.3 kPa or less in the coating solution, the curing rate is moderately delayed and the cloudiness after coating is reduced. It is possible to prevent the coating unevenness and improve the pot life of the coating liquid. Further, those having an ether bond in the molecule are particularly preferred, and glycol ethers are more preferred.

  Specific examples of glycol ethers include, but are not limited to, the following solvents. The solvent name is followed by the boiling point at 1 atmosphere and the vapor pressure at 20 ° C.

Propylene glycol monomethyl ether (PGME)
121 ° C, 1.06 kPa
Propylene glycol monoethyl ether
132.8 ° C, 0.53 kPa
Propylene glycol monobutyl ether
171.1 ° C, <0.13 kPa
Diethylene glycol dimethyl ether 162 ° C, 0.40 kPa
Ethylene glycol monomethyl ether 124.4 ° C, 0.78 kPa
Ethylene glycol monomethyl ether acetate
145 ° C, 0.27 kPa
Ethylene glycol monobutyl ether 171.2 ° C, 0.09 kPa
Ethylene glycol monoethyl ether 135.6 ° C, 0.51 kPa
Ethylene glycol monoethyl ether acetate
156.3 ° C., 0.16 kPa
Ethylene glycol diethyl ether 121 ° C, 1.25 kPa
Particularly preferably, glycol ethers are propylene glycol mono (C1 to C4) alkyl ether and propylene glycol mono (C1 to C4) alkyl ether ester, specifically, propylene glycol monomethyl ether (PGME) and propylene glycol monoethyl. Examples include ether, propylene glycol mono n-propyl ether, propylene glycol monoisopropyl ether, propylene glycol monobutyl ether. Examples of the propylene glycol mono (C1 to C4) alkyl ether ester include propylene glycol monoalkyl ether acetate, and specific examples include propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate. These solvents are preferably added in an amount of 1 to 90% by mass of the total organic solvent in the coating solution.

  A slipping agent is preferably added to the low refractive index layer, and the scratch resistance can be improved by imparting slipperiness. As the slip agent, silicon oil or a wax-like substance is preferably used. For example, a compound represented by the following general formula is preferable.

General formula R ₁ COR ₂
In the formula, R ₁ represents a saturated or unsaturated aliphatic hydrocarbon group having 12 or more carbon atoms. An alkyl group or an alkenyl group is preferable, and an alkyl group or alkenyl group having 16 or more carbon atoms is more preferable. R ₂ represents —OM ₁ group (M ₁ represents an alkali metal such as Na or K), —OH group, —NH ₂ group, or —OR ₃ group (R ₃ represents a saturated or unsaturated group having 12 or more carbon atoms. R ₂ represents a saturated aliphatic hydrocarbon group, preferably an alkyl group or an alkenyl group, and R ₂ is preferably an —OH group, —NH ₂ group, or —OR ₃ group.

  Specifically, higher fatty acids such as behenic acid, stearamide, and pentacoic acid, or derivatives thereof, and carnauba wax, beeswax, and montan wax containing many of these components as natural products can also be preferably used. Polyorganosiloxanes as disclosed in Japanese Patent Publication No. 53-292, higher fatty acid amides as disclosed in US Pat. No. 4,275,146, Japanese Patent Publication No. 58-33541, British Patent No. 927,446 Higher fatty acid esters (esters of fatty acids having 10 to 24 carbon atoms and alcohols having 10 to 24 carbon atoms), and U.S. Patents, as disclosed in JP-A-55-126238 and 58-90633 From higher fatty acid metal salts as disclosed in US Pat. No. 3,933,516, and dicarboxylic acids having up to 10 carbon atoms and aliphatic or cycloaliphatic diols as disclosed in JP-A-51-37217. Polyester compounds, and oligopolyesters from dicarboxylic acids and diols disclosed in JP-A-7-13292 Can.

The addition amount of the slip agent used for the low refractive index layer is preferably 0.01 to 10 mg / m ² .

  It is preferable to add a surfactant, a softening agent, a softening smoothing agent, etc. to the low refractive index layer, and this improves the scratch resistance. Among these, anionic or nonionic surfactants are preferable, and for example, dialkylsulfosuccinic acid sodium salt, nonionic surfactant emulsion of polyhydric alcohol fatty acid ester, and the like are preferable. For example, lipooil NT-6, NT12, NT-33, TC-1, TC-68, TC-78, CW-6, TCF-208, TCF-608, NK oil CS-11, AW-9, AW-10 , AW-20, polysofter N-606, paint additive PC-700 (manufactured by Nikka Chemical Co., Ltd.) and the like are used.

  A preferable addition amount is 0.01 to 3% per solid content contained in the coating solution of the low refractive index layer, and more preferably 0.03 to 1%.

  As the base film used for the antireflection film of the present invention, it is easy to manufacture, the hard coat layer or the antireflection layer is easily adhered, optically isotropic, and optically transparent. Is preferable. Moreover, it is preferable that the refractive index in wavelength 550nm exists in the range of 1.45-1.55.

  Any of these may be used, for example, cellulose ester film, polyester film, polycarbonate film, polyarylate film, polysulfone (including polyethersulfone) film, polyethylene terephthalate, polyethylene naphthalate, etc. Polyester film, polyethylene film, polypropylene film, cellophane, cellulose diacetate film, cellulose acetate butyrate film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film, syndiotactic polystyrene film, polycarbonate film, norbornene resin system Film, polymethylpentene film, polyetherketone film, poly Chromatography ether ketone imides film, polyamide film, fluorocarbon resin film, nylon film, polymethyl methacrylate film or an acrylic film or the like can be mentioned, but is not limited thereto.

  Among these, cellulose triacetate film, polycarbonate film, and polysulfone (including polyethersulfone) are preferable. In the present invention, it is preferable to use a cellulose ester film such as a cellulose triacetate film or a cellulose acetate propionate film. From the viewpoints of cost, transparency, isotropy, adhesiveness and the like. Moreover, it is preferable that the width | variety of a cellulose-ester film is 1.4 m or more, and it is more preferable on production that it is the range of 1.4 m-4 m.

  As the cellulose ester, cellulose acetate, cellulose acetate butyrate, and cellulose acetate propionate are preferable, and among them, cellulose acetate butyrate and cellulose acetate propionate are preferably used.

  In particular, when the substitution degree of acetyl group is X and the substitution degree of propionyl group or butyryl group is Y, an antireflection layer is provided on a support having a mixed fatty acid ester of cellulose in which X and Y are in the following ranges. Is preferred.

2.3 ≦ X + Y ≦ 3.0
0.1 ≦ Y ≦ 1.2
In particular, 2.5 ≦ X + Y ≦ 2.85
It is preferable that 0.3 ≦ Y ≦ 1.2.

  When cellulose ester is used as the base film, the cellulose as a raw material for the cellulose ester is not particularly limited, and examples thereof include cotton linters, wood pulp (derived from coniferous trees and hardwoods), and kenaf. Moreover, the cellulose ester obtained from them can be mixed and used in arbitrary ratios, respectively. When the acylating agent is an acid anhydride (acetic anhydride, propionic anhydride, butyric anhydride), these cellulose esters use an organic solvent such as acetic acid or an organic solvent such as methylene chloride, and It can be obtained by reacting with a cellulose raw material using a protic catalyst.

When the acylating agent is acid chloride (CH ₃ COCl, C ₂ H ₅ COCl, C ₃ H ₇ COCl), the reaction is carried out using a basic compound such as an amine as a catalyst. Specifically, it can be synthesized with reference to the method described in JP-A-10-45804. The cellulose ester is obtained by mixing and reacting the above acylating agent amounts in accordance with the degree of substitution. In the cellulose ester, these acylating agents react with hydroxyl groups of cellulose molecules. Cellulose molecules are composed of many glucose units linked together, and the glucose unit has three hydroxyl groups. The number of acyl groups derived from these three hydroxyl groups is called the degree of substitution (mol%). For example, cellulose triacetate has acetyl groups bonded to all three hydroxyl groups of the glucose unit (actually 2.6 to 3.0).

  As the cellulose ester, a mixed fatty acid ester of cellulose to which a propionate group or a butyrate group is bonded in addition to an acetyl group such as cellulose acetate propionate, cellulose acetate butyrate, or cellulose acetate propionate butyrate is particularly preferably used. . The butyryl group forming butyrate may be linear or branched. Cellulose acetate propionate containing a propionate group as a substituent has excellent water resistance and is useful as a film for liquid crystal image display devices. The measuring method of the substitution degree of an acyl group can be measured according to the provisions of ASTM-D817-96. The number average molecular weight of the cellulose ester is preferably 70,000 to 250,000, since it has a high mechanical strength when molded and an appropriate dope viscosity, and more preferably 80,000 to 150,000.

  As will be described later, these cellulose esters are prepared by adding a cellulose ester solution (dope) generally called a casting method onto a support for casting an endless metal belt or a rotating metal drum, for example. It is manufactured by casting a dope from a pressure die and forming a film. The organic solvent used for the preparation of these dopes is preferably capable of dissolving the cellulose ester and has an appropriate boiling point, for example, methylene chloride, methyl acetate, ethyl acetate, amyl acetate, acetone, tetrahydrofuran, 1,3-dioxolane. 1,4-dioxane, cyclohexanone, ethyl formate, 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoro-1-propanol, 1,3-difluoro-2-propanol, 1,1 , 1,3,3,3-hexafluoro-2-methyl-2-propanol, 1,1,1,3,3,3-hexafluoro-2-propanol, 2,2,3,3,3-penta Fluoro-1-propanol, nitroethane, 1,3-dimethyl-2-imidazolidinone and the like can be mentioned. Organic halogen compounds such as Nkuroraido, dioxolane derivatives, methyl acetate, ethyl acetate, preferred organic solvents are acetone (i.e., good solvent), and as.

  In addition, as shown in the film forming process, when the solvent is dried from the web (dope film) formed on the casting support in the solvent evaporation process, the organic solvent used is used from the viewpoint of preventing foaming in the web. The boiling point of the above-mentioned good solvent is, for example, methylene chloride (boiling point 40.4 ° C), methyl acetate (boiling point 56.32 ° C), acetone (boiling point 56.3 ° C). , Ethyl acetate (boiling point 76.82 ° C.) and the like. Among the good solvents described above, methylene chloride and methyl acetate, which are excellent in solubility, are preferably used, and in particular, methylene chloride is preferably contained in an amount of 50% by mass or more based on the total organic solvent.

  In addition to the organic solvent, it is preferable to contain 0.1 to 30% by mass of an alcohol having 1 to 4 carbon atoms. It is particularly preferable that the alcohol is contained at 5 to 30% by mass. After casting the dope on the casting support, the solvent starts to evaporate and the alcohol ratio increases and the web (dope film) gels, making the web strong and easy to peel off from the casting support. When used as a gelling solvent or when the proportion of these is small, there is also a role of promoting the dissolution of the cellulose ester of the non-chlorine organic solvent.

  Examples of the alcohol having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, tert-butanol and the like. Of these solvents, ethanol is preferred because it has good dope stability, relatively low boiling point, good drying properties, and no toxicity. It is preferable to use a solvent containing 5 to 30% by mass of ethanol with respect to 70 to 95% by mass of methylene chloride. To avoid halogen-containing solvents due to environmental constraints, methyl acetate can be used instead of methylene chloride. At this time, the dope may be prepared by a cooling dissolution method.

  When cellulose ester is used for the base material of the antireflection film of the present invention, the cellulose ester preferably contains a plasticizer.

Although it does not specifically limit as a plasticizer which can be used for a cellulose ester film, Phosphate ester plasticizer, phthalate ester plasticizer, trimellitic ester plasticizer, pyromellitic acid plasticizer, glycolate plastic Agents, citrate ester plasticizers, polyester plasticizers, polyhydric alcohol ester plasticizers, polycarboxylic acid plasticizers, etc., preferably polyhydric alcohol ester plasticizers, phthalate esters, It is preferable to include at least one plasticizer selected from citrate esters, fatty acid esters, glycolate plasticizers, polycarboxylic acid esters and the like. Of these, at least one is preferably a polyhydric alcohol ester plasticizer.

  The polyhydric alcohol ester plasticizer is a plasticizer comprising an ester of a dihydric or higher aliphatic polyhydric alcohol and a monocarboxylic acid, and preferably has an aromatic ring or a cycloalkyl ring in the molecule. Preferably it is a 2-20 valent aliphatic polyhydric alcohol ester.

  The polyhydric alcohol used in the present invention is represented by the following general formula (1).

Formula (1) R _1- (OH) _n
However, R ₁ represents an n-valent organic group, n represents a positive integer of 2 or more, and the OH group represents an alcoholic and / or phenolic hydroxyl group.

  Examples of preferred polyhydric alcohols include the following, but the present invention is not limited to these. Adonitol, arabitol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3- Butanediol, 1,4-butanediol, dibutylene glycol, 1,2,4-butanetriol, 1,5-pentanediol, 1,6-hexanediol, hexanetriol, galactitol, mannitol, 3-methylpentane- Examples include 1,3,5-triol, pinacol, sorbitol, trimethylolpropane, trimethylolethane, and xylitol. In particular, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, sorbitol, trimethylolpropane, and xylitol are preferable.

  There is no restriction | limiting in particular as monocarboxylic acid used for the polyhydric alcohol ester of this invention, Well-known aliphatic monocarboxylic acid, alicyclic monocarboxylic acid, aromatic monocarboxylic acid, etc. can be used. Use of an alicyclic monocarboxylic acid or aromatic monocarboxylic acid is preferred in terms of improving moisture permeability and retention.

  Examples of preferred monocarboxylic acids include the following, but the present invention is not limited thereto.

  As the aliphatic monocarboxylic acid, a fatty acid having a straight chain or a side chain having 1 to 32 carbon atoms can be preferably used. The number of carbon atoms is more preferably 1-20, and particularly preferably 1-10. When acetic acid is contained, the compatibility with the cellulose ester is increased, and it is also preferable to use a mixture of acetic acid and another monocarboxylic acid.

  Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanoic acid, undecylic acid, lauric acid, tridecylic acid, Saturated fatty acids such as myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, melicic acid, laccelic acid, undecylenic acid, olein Examples thereof include unsaturated fatty acids such as acid, sorbic acid, linoleic acid, linolenic acid, and arachidonic acid.

  Examples of preferable alicyclic monocarboxylic acids include cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, cyclooctanecarboxylic acid, and derivatives thereof.

  Examples of preferred aromatic monocarboxylic acids include those in which an alkyl group is introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, and two or more benzene rings such as biphenylcarboxylic acid, naphthalenecarboxylic acid, and tetralincarboxylic acid. The aromatic monocarboxylic acid which has, or those derivatives can be mentioned. Benzoic acid is particularly preferable.

  The molecular weight of the polyhydric alcohol ester is not particularly limited, but is preferably 300 to 1500, and more preferably 350 to 750. A higher molecular weight is preferred because it is less likely to volatilize, and a smaller one is preferred in terms of moisture permeability and compatibility with cellulose ester.

  The carboxylic acid used for the polyhydric alcohol ester may be one kind or a mixture of two or more kinds. Moreover, all the OH groups in the polyhydric alcohol may be esterified, or a part of the OH groups may be left as they are.

  Below, the specific compound of a polyhydric alcohol ester is illustrated.

  The glycolate plasticizer is not particularly limited, but alkylphthalylalkyl glycolates can be preferably used. Examples of alkyl phthalyl alkyl glycolates include methyl phthalyl methyl glycolate, ethyl phthalyl ethyl glycolate, propyl phthalyl propyl glycolate, butyl phthalyl butyl glycolate, octyl phthalyl octyl glycolate, methyl phthalyl ethyl Glycolate, ethyl phthalyl methyl glycolate, ethyl phthalyl propyl glycolate, methyl phthalyl butyl glycolate, ethyl phthalyl butyl glycolate, butyl phthalyl methyl glycolate, butyl phthalyl ethyl glycolate, propyl phthalyl butyl glycol Butyl phthalyl propyl glycolate, methyl phthalyl octyl glycolate, ethyl phthalyl octyl glycolate, octyl phthalyl methyl glycolate, octyl phthalate Ethyl glycolate, and the like.

  Examples of the phthalate ester plasticizer include diethyl phthalate, dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, dioctyl phthalate, dicyclohexyl phthalate, and dicyclohexyl terephthalate.

  Examples of the citrate plasticizer include acetyl trimethyl citrate, acetyl triethyl citrate, and acetyl tributyl citrate.

  Examples of fatty acid ester plasticizers include butyl oleate, methylacetyl ricinoleate, and dibutyl sebacate.

  Polycarboxylic acid ester plasticizers can also be preferably used. Specifically, it is preferable to add the polyvalent carboxylic acid ester described in paragraphs [0015] to [0020] of JP-A No. 2002-265639 as one of the plasticizers.

  Examples of the phosphate ester plasticizer include triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate and the like.

  The total content of the plasticizer in the cellulose ester film is preferably 5 to 30% by mass with respect to the total solid content. Furthermore, 5-20 mass% is preferable, 6-16 mass% is more preferable, Especially preferably, it is 8-13 mass%.

  The polyhydric alcohol ester plasticizer is preferably contained in an amount of 1 to 12% by mass, particularly preferably 3 to 11% by mass.

  The plastic substrate according to the present invention preferably contains an ultraviolet absorber.

  The inventor utilizes the fact that the color tone of the finished film changes depending on the type and amount of the ultraviolet absorber, and changes the color tone of the antistatic agent in the antireflection layer by changing the color tone of the base film. It has been found that it can be controlled.

  Specific examples of ultraviolet absorbers preferably used in the present invention include, for example, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, triazine compounds, nickel complex compounds, and the like. Can be mentioned. Of these, benzotriazole-based ultraviolet absorbers are particularly preferred. Furthermore, it is preferable from the viewpoint of color tone control to use two or more kinds of benzotriazole ultraviolet absorbers.

  As the benzotriazole ultraviolet absorber, a compound represented by the following general formula (1) is preferably used.

In the formula, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ may be the same or different, and are a hydrogen atom, halogen atom, nitro group, hydroxyl group, alkyl group, alkenyl group, aryl group, alkoxy group, acyloxy Represents a group, aryloxy group, alkylthio group, arylthio group, mono- or dialkylamino group, acylamino group or 5- to 6-membered heterocyclic group, and R ₄ and R ₅ are closed to form a 5- to 6-membered carbocyclic ring May be.

Specific examples of the ultraviolet absorbent useful in the present invention are listed below, but the present invention is not limited thereto.
UV-1: 2- (2'-hydroxy-5'-methylphenyl) benzotriazole UV-2: 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzotriazole UV-3 : 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) benzotriazole UV-4: 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl)- 5-Chlorobenzotriazole UV-5: 2- (2'-hydroxy-3 '-(3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) -5'-methylphenyl) benzotriazole UV-6: 2,2-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol)
UV-7: 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole The amount of the UV absorber used depends on the type of UV absorber, the operating conditions, etc. Although not uniform, when the conductive metal compound used in the antireflection layer is ITO and the amount of tin added is in the range of 4.5 to 5.5% by mass with respect to the total of indium and tin, It is preferable to determine the type and amount of the ultraviolet absorber so that the object color due to the transmission of the base film alone is a value of L ^* , a ^* , b ^* within the following range.

(V) Object color by transmission: L ^* value range of 96.9 to 97.4
a ^* value -0.3 to -0.1 range
b ^* value range of 0.4 to 1.0 As an example, when the dry film thickness of the cellulose ester film is 30 to 200 μm, the ultraviolet absorber should be contained in an amount of 0.5 to 4% by mass with respect to the cellulose ester film. Is preferable, and it is further more preferable to make it contain 0.7-3 mass%.

In the present invention, for example, a blue dye may be used as an additive in order to adjust the color of the film. Preferred examples of the dye include anthraquinone dyes. The anthraquinone dye can have an arbitrary substituent at positions 1 to 8 of the anthraquinone. Preferable substituents include an anilino group, a hydroxyl group, an amino group, a nitro group, or a hydrogen atom that may be substituted. The addition amount of the films of these dyes 0.1 to 1000 / m ² to maintain the transparency of the film is preferably 10-100 [mu] g / m ^2.

  In the present invention, a fluorescent brightening agent may be used as an additive to adjust the color of the film.

  It is preferable to add a blue dye or a fluorescent brightening agent to the additive solution of the ultraviolet absorber because the color of the film can be easily adjusted.

  The following matting agent can also be added to the base film of the present invention. The dynamic friction coefficient is a dynamic friction coefficient between the film surface and the back surface, and is preferably 2 or less, more preferably 1.5 or less, when measured according to JIS-K-7125 (1987). It is more preferably 0.0 or less, further preferably 0.5 or less, and further preferably 0.2 or less. Although the coefficient of dynamic friction can be lowered by increasing the amount of matting agent added, the haze value of the film tends to increase, so the amount added is determined by a balance between the two.

  If the film is difficult to slip, the films may be blocked and the handling property may be poor. Films according to the present invention include inorganic fine particles such as silicon dioxide, titanium dioxide, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, and calcium phosphate, crosslinked polymers such as crosslinked acrylic resins, and organic matter. It is preferable to contain a matting agent such as

  In order to reduce the haze of the film, it is preferable that fine particles such as silicon dioxide are surface-treated with an organic substance. Preferred organic materials for the surface treatment include halosilanes, alkoxysilanes, silazanes, siloxanes, and the like. The larger the average diameter of the fine particles, the larger the mat effect and the better the transparency, the smaller the average diameter. Therefore, the average primary particle diameter of the fine particles is 0.5 μm or less, preferably 5 to 50 nm, more preferably 7 to 14 nm. It is. Examples of the silicon dioxide fine particles include AEROSIL 200, 200V, 300, R972, R972V, R974, R202, R812, OX50, and TT600 manufactured by Nippon Aerosil Co., Ltd., preferably AEROSIL R972V, R974, R202, R812 and the like. Can be mentioned. The matting agent is preferably blended so that the haze of the film is 0.6% or less and the dynamic friction coefficient is 0.5 or less. The amount of the matting agent used for this purpose is preferably 0.001 to 0.3% with respect to the cellulose ester.

  It is possible to add other additives to each dope of the present invention as necessary. For example, infrared absorbing dyes can be added to the film dope. If necessary, an antistatic agent can be added to the surface layer or inside.

  As the optical properties of the substrate, those having an in-plane retardation Ro of 0 to 1000 nm are preferably used, and those having a thickness direction retardation Rt of 0 to 300 nm are preferably used depending on the application. The wavelength dispersion characteristic is preferably such that R600 / R450 is 0.7 to 1.3, particularly preferably 1.0 to 1.3. Here, R450 and R600 are in-plane retardation by light having wavelengths of 450 nm and 600 nm, respectively.

  The in-plane retardation Ro is measured using a automatic birefringence meter KOBRA-21ADH (manufactured by Oji Scientific Instruments) at a wavelength of 590 nm, and the obtained refractive indexes nx, ny, nz And the thickness d of the film can be calculated by the following formula. The retardation value Rt in the film thickness direction is preferably 0 to 150 nm, more preferably 0 to 70 nm, depending on the application.

Formula Ro = (nx−ny) × d
Formula Rt = ((nx + ny) / 2−nz) × d
The antireflection film of the present invention can be provided with an active energy ray curable resin layer or a thermosetting resin layer. In particular, it is preferable to provide an active energy ray-curable resin layer on a substrate and to provide an antireflection layer thereon. Here, an example in which an active energy ray curable resin layer is used for these active energy ray curable resins, particularly for hard coat coating, will be described.

  It is preferable to provide a hard coat layer between the antireflection layer including the low refractive index layer and the high refractive index layer of the present invention and the substrate. The hard coat layer may be provided directly on the substrate, or may be provided on another layer such as an antistatic layer or an undercoat layer.

  The hard coat layer preferably contains an active energy ray-curable resin that is cured by irradiation with active energy rays such as ultraviolet rays.

  The hard coat layer preferably has a refractive index in the range of 1.45 to 1.65 from the viewpoint of optical design for obtaining a low reflective film. The film thickness of the hard coat layer can be in the range of 0.5 to 15 μm. This is because when the film thickness is less than 0.5 μm, sufficient durability and impact resistance cannot be obtained, and when the film thickness exceeds 15 μm, there is a problem in flexibility or economy. More preferably, it is 0.5-7 micrometers.

  The active energy ray-curable resin layer refers to a layer mainly composed of a resin that is cured through a crosslinking reaction or the like by irradiation with active energy rays such as ultraviolet rays or electron beams. Typical examples of the active energy ray curable resin include an ultraviolet curable resin and an electron beam curable resin, but a resin that is cured by irradiation with an active energy ray other than an ultraviolet ray or an electron beam may be used. Examples of the ultraviolet curable resin include an ultraviolet curable acrylic urethane resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, and an ultraviolet curable epoxy resin. I can do it.

  Photoreaction initiators can also be used as photosensitizers. Specific examples include acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and derivatives thereof. Moreover, when using a photoreactant for the synthesis | combination of an epoxy acrylate-type resin, sensitizers, such as n-butylamine, a triethylamine, a tri-n-butylphosphine, can be used. The photoreaction initiator or photosensitizer contained in the ultraviolet curable resin composition excluding the solvent component that volatilizes after coating and drying is preferably 2.5 to 6% by mass of the composition.

  Examples of the resin monomer include general monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, vinyl acetate, benzyl acrylate, cyclohexyl acrylate, and styrene as monomers having one unsaturated double bond. In addition, monomers having two or more unsaturated double bonds include ethylene glycol diacrylate, propylene glycol diacrylate, divinylbenzene, 1,4-cyclohexane diacrylate, 1,4-cyclohexyldimethyl adiacrylate, and the aforementioned trimethylol propane tri Examples thereof include acrylate and pentaerythritol tetraacryl ester.

  Moreover, you may include a ultraviolet absorber in an ultraviolet curable resin composition to such an extent that the photocuring of an ultraviolet curable resin composition is not prevented. As an ultraviolet absorber, the same thing as the ultraviolet absorber which may be used for the said base material can be used.

  In order to increase the heat resistance of the cured layer, an antioxidant that does not inhibit the photocuring reaction can be selected and used. For example, hindered phenol derivatives, thiopropionic acid derivatives, phosphite derivatives and the like can be mentioned. Specifically, for example, 4,4′-thiobis (6-t-3-methylphenol), 4,4′-butylidenebis (6-t-butyl-3-methylphenol), 1,3,5-tris ( 3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) mesitylene, di-octadecyl-4-hydroxy -3,5-di-t-butylbenzyl phosphate and the like.

  Examples of the ultraviolet curable resin include Adekaoptomer KR, BY series KR-400, KR-410, KR-550, KR-566, KR-567, BY-320B (above, manufactured by Asahi Denka Kogyo Co., Ltd.) Koeihard A-101-KK, A-101-WS, C-302, C-401-N, C-501, M-101, M-102, T-102, D-102, NS-101, FT-102Q8, MAG-1-P20, AG-106, M-101-C (manufactured by Guangei Chemical Industry Co., Ltd.), Seika Beam PHC2210 (S), PHCX-9 (K-3), PHC2213, DP -10, DP-20, DP-30, P1000, P1100, P1200, P1300, P1400, P1500, P1600, SCR900 (above, Daiichi Seika Kogyo Co., Ltd. Manufactured), KRM7033, KRM7039, KRM7130, KRM7131, UVECRYL29201, UVECRYL29202 (above, Daicel UC Corporation), RC-5015, RC-5016, RC-5020, RC-5031, RC-5100, RC-5102, RC-5120, RC-5122, RC-5152, RC-5171, RC-5180, RC-5181 (manufactured by Dainippon Ink & Chemicals, Inc.), Aulex No. 340 clear (manufactured by China Paint Co., Ltd.), Sun Rad H-601 (manufactured by Sanyo Chemical Industries, Ltd.), SP-1509, SP-1507 (above, Showa Polymer Co., Ltd.), RCC-15C (Grace Japan Co., Ltd.), Aronix M-6100, M-8030, M-8060 (manufactured by Toagosei Co., Ltd.), or other commercially available products can be used as appropriate.

  The coating composition of the active energy ray-curable resin layer preferably has a solid content concentration of 10 to 95% by mass, and an appropriate concentration is selected depending on the coating method.

As the light source for forming the cured coating layer by photocuring reaction, any light source that generates ultraviolet rays can be used for the active energy ray curable resin. The irradiation conditions vary depending on individual lamps, but the amount of light irradiated may be any degree 20~10000mJ / cm ^2, preferably from 50~2000mJ / cm ^2. From the near ultraviolet region to the visible light region, it can be used by using a sensitizer having an absorption maximum in that region.

  The solvent for coating the active energy ray-curable resin layer can be appropriately selected from, for example, hydrocarbons, alcohols, ketones, esters, glycol ethers, and other solvents, or can be used by mixing. Preferably, a solvent containing 5% by mass or more, more preferably 5 to 80% by mass or more of propylene glycol mono (C1-C4) alkyl ether or propylene glycol mono (C1-C4) alkyl ether ester is used.

  As a coating method of the active energy ray-curable resin composition coating solution, a known method such as a gravure coater, a spinner coater, a wire bar coater, a roll coater, a reverse coater, an extrusion coater, or an air doctor coater can be used. The coating amount is suitably 0.1 to 30 μm, preferably 0.5 to 15 μm in terms of wet film thickness. The coating speed is preferably 10 to 60 m / min.

  The active energy ray-curable resin composition is applied and dried, and then irradiated with ultraviolet rays. The irradiation time is preferably 0.5 seconds to 5 minutes, and 3 seconds to 2 minutes from the curing efficiency and work efficiency of the ultraviolet curable resin. Is more preferable.

  In this way, a cured coating layer can be obtained. In order to provide antiglare properties to the surface of the liquid crystal display panel, to prevent adhesion to other substances, and to improve scratch resistance, the cured coating layer Inorganic or organic fine particles can also be added to the coating composition.

  Examples of the inorganic fine particles include silicon oxide, titanium oxide, aluminum oxide, tin oxide, zinc oxide, calcium carbonate, barium sulfate, talc, kaolin, calcium sulfate and the like.

  The organic fine particles include polymethacrylic acid methyl acrylate resin powder, acrylic styrene resin powder, polymethyl methacrylate resin powder, silicon resin powder, polystyrene resin powder, polycarbonate resin powder, benzoguanamine resin powder, melamine resin. Examples thereof include powder, polyolefin resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, and polyfluoroethylene resin powder. These can be used in addition to the ultraviolet curable resin composition. The average particle size of these fine particle powders is 0.01 to 10 μm, and the amount used is desirably 0.1 to 20 parts by mass with respect to 100 parts by mass of the ultraviolet curable resin composition. . In order to impart an antiglare effect, it is preferable to use 1 to 15 parts by mass of fine particles having an average particle diameter of 0.1 to 1 μm with respect to 100 parts by mass of the ultraviolet curable resin composition.

  When such fine particles are added, the type and amount of the metal oxide particles in the antireflection layer and the type and amount of the ultraviolet absorber in the film are adjusted in view of the degree of coloring of the fine particles. It is preferable.

  By adding such fine particles to the ultraviolet curable resin, it is possible to form an antiglare layer having preferable irregularities having a center line average surface roughness Ra of 0.1 to 0.5 μm. Further, when such fine particles are not added to the ultraviolet curable resin composition, the hard surface having a good smooth surface with a center line average surface roughness Ra of less than 0.05 μm, more preferably less than 0.002 to 0.04 μm. A coat layer can be formed.

  In addition, as an element that fulfills the anti-blocking function, 0.1 to 5 parts by mass of ultrafine particles having a volume average particle size of 0.005 to 0.1 μm with the same components as the above-described particles are added to 100 parts by mass of the resin composition Can also be used.

In this invention, it is preferable to have 1-500 pieces / 0.01 mm < ² > of protrusions with a height of 0.1-10 micrometers on the back surface of the antireflection film provided with the antireflection layer. Preferably from 10 to 400 pieces /0.01mm ^2, more preferably from 15 to 300 pieces /0.01mm ^2. As a result, even if winding in a roll once during the application of each optical interference layer, not only blocking can be prevented, but also the coating unevenness when coating the next optical interference layer is significantly reduced. I can do it. The cause of coating unevenness is not completely clarified, but it is presumed that as one of the causes, peeling electrification at the time of feeding a film wound up in a roll shape to the coating process is related. By adding fine particles to the base film, it is possible to have 1 to 500 protrusions / 0.01 mm ² with a height of 0.1 to 10 μm on the back surface. At this time, the base film can be formed into a multilayer structure, and fine particles can be included only in the surface layer.

  The fine particles to be added may be organic compounds or inorganic compounds, such as silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, kaolin, talc, calcined calcium silicate, hydrated calcium silicate, silicic acid. It is preferable to contain inorganic fine particles such as aluminum, magnesium silicate, calcium phosphate, and crosslinked polymer fine particles. Of these, silicon dioxide is preferable because it can reduce the haze of the film. The average particle size of the secondary particles of the fine particles is 0.1 to 10 μm, and the content thereof is preferably 0.04 to 0.3% by mass with respect to the cellulose ester of the base material. In many cases, fine particles such as silicon dioxide are surface-treated with an organic substance, but this is preferable because the haze of the film can be reduced. Preferred organic substances for the surface treatment include halosilanes, alkoxysilanes (particularly alkoxysilanes having a methyl group), silazane, siloxane and the like. The larger the average particle size of the fine particles, the greater the mat effect, and on the contrary, the smaller the average particle size, the better the transparency. Therefore, the average particle size of the preferred primary particles is 5 to 50 nm, more preferably 7 to 16 nm. It is.

  Examples of the fine particles of silicon dioxide include AEROSIL (Aerosil) 200, 200V, 300, R972, R972V, R974, R202, R812, OX50, TT600, etc. manufactured by Aerosil Co., Ltd., preferably AEROSIL (Aerosil) 200V. , R972, R972V, R974, R202, R812. Two or more kinds of these fine particles may be used in combination. When using 2 or more types together, it can mix and use in arbitrary ratios. In this case, fine particles having different average particle sizes and materials, for example, AEROSIL (Aerosil) 200V and R972V can be used in a mass ratio of 0.1: 99.9 to 99.9: 0.1.

  The fine particles may be dispersed together with cellulose ester, other additives and organic solvent at the time of preparing the dope, but the dope is prepared in a sufficiently dispersed state like the fine particle dispersion separately from the cellulose ester solution. Is preferred. In order to disperse the fine particles, it is preferable that the fine particles are preliminarily dispersed in an organic solvent and then finely dispersed with a disperser (high pressure disperser) having a high shearing force. After that, it is preferable to disperse in a larger amount of organic solvent, merge with the cellulose ester solution, and mix with an in-line mixer to obtain a dope. In this case, an ultraviolet absorbent may be added to the fine particle dispersion to form an ultraviolet absorbent liquid.

  When surface processing is performed only on one side of the film, or when different types or different levels of surface processing are performed on both sides, a curl phenomenon that the film is rounded easily occurs. Curling is inconvenient and difficult to handle when using this to produce a polarizing plate.

In order to prevent curling, an anti-curl layer can be provided on the opposite side of the hard coat layer. That is, the degree of curling is balanced by imparting the property of curling with the surface provided with the anti-curl layer inside. The anti-curl layer is preferably applied also as a blocking layer. In this case, the coating composition can contain the above-mentioned inorganic fine particles and / or organic fine particles for imparting a blocking preventing function. (This layer is also referred to as a backcoat layer.)
The imparting of the anti-curl function is specifically performed by applying a composition containing a solvent that dissolves or swells the substrate. In addition to the solvent to be dissolved or the mixture of solvents to be swollen, the solvent to be used may further include a solvent that does not dissolve. These are performed using a composition and a coating amount mixed at an appropriately selected ratio depending on the curl degree of the resin film and the kind of the resin.

  In order to enhance the curl prevention function, it is effective to increase the mixing ratio of the solvent to be dissolved or the solvent to be swollen and to decrease the ratio of the solvent not to be dissolved. The mixing ratio is preferably (solvent to be dissolved or solvent to be swollen) :( solvent not to be dissolved) = 10: 0 to 1: 9.

  Examples of the solvent for dissolving or swelling contained in such a mixed composition include benzene, toluene, xylene, dioxane, acetone, methyl ethyl ketone, N, N-dimethylformamide, methyl acetate, ethyl acetate, trichloroethylene, methylene chloride, ethylene. There are chloride, tetrachloroethane, trichloroethane, chloroform and the like. Examples of the solvent that does not dissolve include methanol, ethanol, n-propyl alcohol, i-propyl alcohol, and n-butanol.

  These coating compositions are preferably applied to the surface of the substrate using a gravure coater, dip coater, reverse roll coater, extrusion coater or the like, with a wet film thickness of 1 to 100 μm, particularly preferably 5 to 30 μm.

  This coating composition can contain a resin. Examples of the resin used here include vinyl chloride / vinyl acetate copolymer, vinyl chloride resin, vinyl acetate resin, vinyl acetate and vinyl alcohol copolymer, Partially hydrolyzed vinyl chloride / vinyl acetate copolymer, vinyl chloride / vinylidene chloride copolymer, vinyl chloride / acrylonitrile copolymer, ethylene / vinyl alcohol copolymer, chlorinated polyvinyl chloride, ethylene / vinyl chloride copolymer Polymers, vinyl polymers such as ethylene / vinyl acetate copolymers or copolymers, nitrocellulose, cellulose acetate propionate, diacetyl cellulose, cellulose acetate butyrate, cellulose ester resins such as cellulose acetate propionate resin, Of maleic acid and / or acrylic acid Polymer, acrylate copolymer, acrylonitrile / styrene copolymer, chlorinated polyethylene, acrylonitrile / chlorinated polyethylene / styrene copolymer, methyl methacrylate / butadiene / styrene copolymer, acrylic resin, polyvinyl acetal resin, polyvinyl Butyral resin, polyester polyurethane resin, polyether polyurethane resin, polycarbonate polyurethane resin, polyester resin, polyether resin, polyamide resin, amino resin, rubber resin such as styrene / butadiene resin, butadiene / acrylonitrile resin, silicone resin, fluorine resin Although resin etc. can be mentioned, it is not limited to these.

  As acrylic resins, Acrypet MD, VH, MF, V (manufactured by Mitsubishi Rayon Co., Ltd.), Hyperl M4003, M-4005, M-4006, M-4202, M-5000, M-5001, M-4501 (manufactured by Negami Kogyo Co., Ltd.), Dialnal BR-50, BR-52, BR-53, BR-60, BR-64, BR-73, BR-75, BR-77, BR- 79, BR-80, BR-82, BR-83, BR-85, BR-87, BR-88, BR-90, BR-93, BR-95, BR-100, BR-101, BR-102, BR-105, BR-106, BR-107, BR-108, BR-112, BR-113, BR-115, BR-116, BR-117, BR-118 (above, manufactured by Mitsubishi Rayon Co., Ltd.), etc. Used It is.

  Particularly preferably, cellulose ester resins such as diacetyl cellulose and cellulose acetate propionate are used.

  The anti-curl layer may be applied before or after an optical functional layer (for example, an antistatic layer, a hard coat layer, or an optical interference layer) is applied on the opposite side of the base material. When the layer also serves as an anti-blocking layer, it is desirable to coat it first.

  The coating method of the composition of each layer provided in the antireflection film of the present invention includes dipping, spin coating, knife coating, bar coating, air doctor coating, blade coating, squeeze coating, reverse roll coating, gravure roll coating, curtain coating. A known coating method such as spray coating or die coating can be used, and a coating method capable of continuous coating or thin film coating is preferably used.

  When applying the composition to a substrate, the thickness of the layer, coating uniformity, and the like can be controlled by adjusting the solid content concentration and the coating amount in the coating solution. Moreover, in order to improve the applicability | paintability of a composition, you may add a trace amount surfactant etc. in a coating liquid.

<Deflection plate>
When the antireflection film according to the present invention is used as the protective film for a polarizing plate on the outermost surface of the liquid crystal display device, it is preferable to produce a polarizing plate by pasting at least one surface of the polarizing film with the antireflection film of the present invention. .

  Here, the polarizing film refers to an element that allows only light having a plane of polarization in a certain direction to pass through, but there are one in which a polyvinyl film is dyed with iodine and one in which a dichroic dye is dyed. These are formed by forming a polyvinyl alcohol aqueous solution into a film and uniaxially stretching it to dye it. However, after dyeing and uniaxially stretching, those subjected to a durability treatment with a boron compound are preferably used. The antireflection film of the present invention is bonded as a protective film for a polarizing plate to at least one of the polarizing films thus prepared to form a polarizing plate. When using as a polarizing plate protective film to produce a polarizing plate by using a 5% aqueous solution of completely saponified polyvinyl alcohol as an adhesive to produce a polarizing plate, the antireflective film according to the present invention is subjected to a treatment such as alkali saponification. Alkali resistance is required.

  As a polarizing film protective film used on the other surface of the polarizing film, as a commercially available cellulose ester film, KC8UX2M, KC4UX, KC5UX, KC4UY, KC8UY, KC12UR, KC8UCR-1, KC8UCR-2, KC8UCR-3, KC8UCR- 4 (manufactured by Konica Minolta Opto Co., Ltd.) and the like are preferably used. In contrast to the antireflection film of the present invention, the polarizing plate protective film used on the other surface has an in-plane retardation Ro of 590 nm, an optical compensation having a phase difference of 20 to 70 nm and Rt of 70 to 400 nm. A film is preferred.

<Display device>
By incorporating the antireflection film or polarizing plate of the present invention into a display device, various display devices of the present invention having excellent visibility can be produced. The antireflection film of the present invention is a reflective type, transmissive type, transflective type LCD or TN type, STN type, OCB type, HAN type, VA type (PVA type, MVA type), IPS type, etc. Preferably used. In addition, the antireflection film of the present invention has remarkably little uneven coloring and glare in the reflected light of the antireflection layer, and is excellent in flatness, such as a plasma display, a field emission display, an organic EL display, an inorganic EL display, and electronic paper. It is preferably used for various display devices. In particular, a large-screen display device with a screen of 30 or more types, particularly 30 to 54 types, has less color unevenness, glare and wavy unevenness, and has an effect that eyes are not tired even during long-time viewing.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Example 1
An antireflection film was prepared as follows. The refractive index and film thickness of the optical interference layer were measured by the following methods.

<Measurement of refractive index and film thickness>
The refractive index and film thickness of the medium refractive index layer, high refractive index layer, and low refractive index layer were determined from the measurement results of the spectral reflectance of each layer provided as a single layer on the hard coat layer. Spectral reflectance was measured using FE-3000 (manufactured by Otsuka Electronics Co., Ltd.) after roughening the back surface of the sample and performing light absorption treatment with black spray to prevent reflection of light on the back surface. It was. The spectral reflectance was analyzed and fitted with FE-3000 software to obtain the refractive index and film thickness.

[Preparation of antireflection film 1]
<Production of cellulose ester films 1 to 4>
(Preparation of dope solution A)
Cellulose ester (cellulose triacetate synthesized from linter cotton)
100 parts by mass (Mn = 148000, Mw = 310000, Mw / Mn = 2.1)
Triphenyl phosphate 9.5 parts by mass Ethylphthalyl ethyl glycolate 2.2 parts by mass Methylene chloride 440 parts by mass Ethanol 40 parts by mass Azumi filter paper No. 24, and the dope liquid A was prepared. The dope solution A was filtered with Finemet NF manufactured by Nippon Seisen Co., Ltd. in the film production line. (A part of the dope solution A was also used for preparing the following inline additive solution A.)
(Silicon dioxide dispersion A)
Aerosil 200V (manufactured by Nippon Aerosil Co., Ltd.) 2 parts by mass (average diameter of primary particles 12 nm, apparent specific gravity 100 g / liter)
18 parts by mass or more of ethanol was stirred and mixed with a dissolver for 30 minutes, and then dispersed with Manton Gorin. The liquid turbidity after dispersion was 100 ppm. 18 parts by mass of methylene chloride was added to the silicon dioxide dispersion with stirring, and the mixture was stirred and mixed with a dissolver for 30 minutes to prepare a silicon dioxide dispersion dilution A.

(Preparation of inline additive solution A)
Methylene chloride 100 parts by weight Dope solution A 34 parts by weight Tinuvin 109 (manufactured by Ciba Specialty Chemicals) 5 parts by weight Tinuvin 171 (manufactured by Ciba Specialty Chemicals) 5 parts by weight Tinuvin 326 (manufactured by Ciba Specialty Chemicals) 3 parts by mass or more was put into a closed container, heated, stirred and completely dissolved and filtered.

To this, 20 parts by mass of silicon dioxide dispersion dilution A was added with stirring, and the mixture was further stirred for 60 minutes, and then filtered with Advantech Toyo's polypropylene wind cartridge filter TCW-PPS-1N. Was prepared.
In-line additive solution A was filtered with Finemet NF manufactured by Nippon Seisen Co., Ltd. in the in-line additive solution line. Add 2.5 parts by mass of the filtered in-line additive liquid A to 100 parts by mass of the filtered dope liquid A, mix thoroughly with an in-line mixer (Toray static type in-pipe mixer Hi-Mixer, SWJ), and then belt Using a casting apparatus, the film was uniformly cast on a stainless steel band support at a temperature of 35 ° C. and a width of 1.8 m. With the stainless steel band support, the solvent was evaporated until the residual solvent amount became 120%, and then peeled off from the stainless steel band support. The peeled cellulose ester web was evaporated at 40 ° C., slit to 1.6 m width, and then stretched 1.1 times at 120 ° C. in the TD direction (direction perpendicular to the film transport direction) with a tenter. . The residual solvent amount when starting stretching with a tenter was 25%. Then, drying was completed while transporting the heating zone at 110 ° C. and 120 ° C. with a number of rolls, slitting to a width of 1.4 m, winding at both ends of the film with a width of 15 mm and an average height of 10 μm, A cellulose ester film 1 was obtained. The draw ratio in the MD direction (the same direction as the film transport direction) immediately after peeling calculated from the rotational speed of the stainless steel band support and the operating speed of the tenter was 1.1 times. The residual solvent amount of the cellulose ester film was 0.1%, the average film thickness was 80 μm, and the winding number was 3000 m.

In addition, the L ^* a ^* b ^* value of the object color by permeation | transmission of the cellulose-ester film 1 was measured with the measuring method mentioned later, As a result, L ^* = 97.2, a ^* =-0.2, b ^* = 0. It was 5.

  Next, the following inline additive liquids B to D were prepared and used in place of the inline additive liquid A of the cellulose ester film 1, and cellulose ester films 2 to 4 were similarly prepared.

The L ^* a ^* b ^* values of the object color due to the transmission through the cellulose ester film 2 are L ^* = 97.3, a ^* = 0.4, b ^* = 0.1, and the cellulose ester film 3 has L ^* = 96. ^{.9, a * = -0.1, b} * = 0.9, the cellulose ester film ^{4, L * = 96.2, a *} = -0.1, was b ^* = 1.2.

(Preparation of inline additive solution B)
Methylene chloride 100 parts by weight Dope solution A 34 parts by weight Tinuvin 109 (manufactured by Ciba Specialty Chemicals) 2 parts by weight Tinuvin 171 (manufactured by Ciba Specialty Chemicals) 2 parts by weight Tinuvin 326 (manufactured by Ciba Specialty Chemicals) 1 part by mass (Preparation of inline additive liquid C)
Methylene chloride 100 parts by weight Dope solution A 34 parts by weight Tinuvin 109 (manufactured by Ciba Specialty Chemicals) 10 parts by weight Tinuvin 171 (manufactured by Ciba Specialty Chemicals) 10 parts by weight Tinuvin 326 (manufactured by Ciba Specialty Chemicals) 6 parts by mass (Preparation of inline additive solution D)
Methylene chloride 100 parts by weight Dope A 34 parts by weight Tinuvin 109 (manufactured by Ciba Specialty Chemicals) 15 parts by weight Tinuvin 171 (manufactured by Ciba Specialty Chemicals) 15 parts by weight Tinuvin 326 (manufactured by Ciba Specialty Chemicals) 9 parts by mass <Preparation of hard coat film>
The following hard-coat layer composition (C-1) was apply | coated to the single side | surface of the said produced cellulose-ester films 1-4 so that it might become a dry film thickness of 3.5 micrometers, and it dried at 80 degreeC for 1 minute. Next, it was cured under a condition of 150 mJ / cm ^{2 with} a high-pressure mercury lamp (80 W) to produce a hard coat film having a hard coat layer. The refractive index of the hard coat layer was 1.50.

<Hard coat layer composition (C-1)>
Dipentaerythritol hexaacrylate monomer 108 parts by mass Dipentaerythritol hexaacrylate dimer 36 parts by mass Dipentaerythritol hexaacrylate trimer or higher component 36 parts by mass Irgacure 184 (manufactured by Ciba Specialty Chemicals) 2 parts by mass Propylene glycol monomethyl ether 180 parts by mass Ethyl acetate 120 parts by mass << Preparation of medium refractive index layer film >>
On the hard coat layer of the hard coat film, the following medium refractive index layer compositions (M-1) to (M-6) were applied by an extrusion coater, and the conditions were 1 minute at 80 ° C. and 0.1 m / second. Dried. At this time, a non-contact floater was used until completion of touch drying (a state where the coated surface was touched with a finger and felt dry). As the non-contact floater, a horizontal floater type air tumbler manufactured by Belmatik was used. The static pressure in the floater was set to 9.8 kPa, and the floater was lifted uniformly in the width direction of about 2 mm and conveyed. After drying, a medium refractive index layer film having a medium refractive index layer was produced by curing by irradiating ultraviolet rays with 130 mJ / cm ² using a high pressure mercury lamp (80 W). The medium refractive index layer had a thickness of 84 nm and a refractive index of 1.66. Only the antireflection film 2 was adjusted to have a thickness of the medium refractive index layer of 80 nm.

  Table 1 shows the product dx when the thickness of the antireflection film is d (nm) and the content ratio of the conductive fine particles is x.

<Medium Refractive Index Layer Composition M-1>
ELCOM V-2504 (manufactured by Catalyst Kasei Kogyo Co., Ltd., ITO sol, solid content 20%)
100g
Dipentaerythritol hexaacrylate 6.4g
Irgacure 184 (Ciba Specialty Chemicals Co., Ltd.) 1.6g
Tetrabutoxy titanium 4.0g
10% FZ-2207 (Nihon Unicar Co., Ltd., propylene glycol monomethyl ether solution) 3.0 g
Isopropyl alcohol 530g
90g of methyl ethyl ketone
265 g of propylene glycol monomethyl ether
<Medium Refractive Index Layer Composition (M-2)>
Solid content 15% titanium oxide fine particle dispersion (RTSDNB15WT% -G0 manufactured by CII Kasei Kogyo Co., Ltd.) 270 g
Dipentaerythritol hexaacrylate (KAYARAD DPHA Nippon Kayaku Co., Ltd.) 55g
Irgacure 907 (Ciba Specialty Chemicals Co., Ltd.) 3g
Kayacure DETX (Nippon Kayaku Co., Ltd.) 1g
Linear dimethyl silicone-EO block copolymer (FZ-2207, Nihon Unicar) 1g
1470g of propylene glycol monomethyl ether
Isopropyl alcohol 2720g
490 g of methyl ethyl ketone
<Medium Refractive Index Layer Composition M-3>
ELCOM V-2504 (manufactured by Catalyst Kasei Kogyo Co., Ltd., ITO sol, solid content 20%)
120g
Dipentaerythritol hexaacrylate 5.33g
Irgacure 184 (Ciba Specialty Chemicals Co., Ltd.) 1.28g
Tetrabutoxy titanium 3.33g
10% FZ-2207 (Nihon Unicar Co., Ltd., propylene glycol monomethyl ether solution) 3.0 g
Isopropyl alcohol 530g
90g of methyl ethyl ketone
265 g of propylene glycol monomethyl ether
<Medium Refractive Index Layer Composition M-4>
ELCOM V-2504 (manufactured by Catalyst Kasei Kogyo Co., Ltd., ITO sol, solid content 20%)
80g
Dipentaerythritol hexaacrylate 8g
Irgacure 184 (Ciba Specialty Chemicals Co., Ltd.) 2g
Tetrabutoxy titanium 5g
10% FZ-2207 (Nihon Unicar Co., Ltd., propylene glycol monomethyl ether solution) 3.0 g
Isopropyl alcohol 530g
90g of methyl ethyl ketone
265 g of propylene glycol monomethyl ether
<Medium Refractive Index Layer Composition M-5>
ELCOM V-2504 (manufactured by Catalyst Kasei Kogyo Co., Ltd., ITO sol, solid content 20%)
60g
Dipentaerythritol hexaacrylate 10.7g
Irgacure 184 (Ciba Specialty Chemicals Co., Ltd.) 2.67g
Tetrabutoxy titanium 6.67g
10% FZ-2207 (Nihon Unicar Co., Ltd., propylene glycol monomethyl ether solution) 3.0 g
Isopropyl alcohol 530g
90g of methyl ethyl ketone
265 g of propylene glycol monomethyl ether
<Medium Refractive Index Layer Composition M-6>
ITRANB (catalyst chemical industry Co., Ltd., ITO sol) 100g
Dipentaerythritol hexaacrylate 6.4g
Irgacure 184 (Ciba Specialty Chemicals Co., Ltd.) 1.6g
Tetrabutoxy titanium 4.0g
10% FZ-2207 (Nihon Unicar Co., Ltd., propylene glycol monomethyl ether solution) 3.0 g
Isopropyl alcohol 530g
90g of methyl ethyl ketone
265 g of propylene glycol monomethyl ether
<< Production of high refractive index layer film >>
On the medium refractive index layer film, the following high refractive index layer composition (H-1) was applied by an extrusion coater and dried for 1 minute under the conditions of 80 ° C. and 0.1 m / second. At this time, a non-contact floater was used until completion of touch drying (a state where the coated surface was touched with a finger and felt dry). The non-contact floater was made to have the same conditions as the medium refractive index layer film 1. After drying, ultraviolet rays were irradiated by 130 mJ / cm ² using a high pressure mercury lamp (80 W) and cured to produce a high refractive index layer film having a high refractive index layer.

<High refractive index layer composition (H-1)>
95 parts by mass of tetra (n) butoxytitanium dimethylpolysiloxane (KF-96-1000CS manufactured by Shin-Etsu Chemical Co., Ltd.) 1 part by mass of γ-methacryloxypropyltrimethoxysilane (KBM503 manufactured by Shin-Etsu Chemical Co., Ltd.)
5 parts by mass Propylene glycol monomethyl ether 1750 parts by mass Isopropyl alcohol 3450 parts by mass Methyl ethyl ketone 600 parts by mass The thickness of the high refractive index layer of this high refractive index layer film is shown in Table 1. The refractive index was 1.82.

On the high refractive index layer film 1, the following low refractive index layer composition (L-1) was applied by an extrusion coater and dried for 1 minute under the conditions of 80 ° C. and 0.1 m / second. At this time, a non-contact floater was used until completion of touch drying (a state where the coated surface was touched with a finger and felt dry). The non-contact floater was made to have the same conditions as the medium refractive index layer film 1. After drying, the film was cured by irradiating with ultraviolet rays of 130 mJ / cm ² using a high-pressure mercury lamp (80 W) and further thermally cured at 120 ° C. for 5 minutes to produce an antireflection film having a low refractive index layer.

<Preparation of tetraethoxysilane hydrolyzate A>
Tetraethoxysilane hydrolyzate A was prepared by mixing 25 g of tetraethoxysilane and 222 g of ethanol, adding 54 g of a 1.5% by weight aqueous solution of citric acid monohydrate, and stirring for 3 hours at room temperature. did.

<Low refractive index layer composition (L-1)>
Tetraethoxysilane hydrolyzate A 103 parts by mass γ-methacryloxypropyltrimethoxysilane (Shin-Etsu Chemical KBM503)
1 part by mass Linear dimethylsilicone-EO block copolymer (Nippon Unicar FZ-2207) 0.1 part by mass Propylene glycol monomethyl ether 270 parts by mass Isopropyl alcohol 270 parts by mass In addition, the low refractive index layer of this low reflection laminate The thickness is shown in Table 1. The refractive index was 1.45.

  As described above, antireflection films 1 to 15 shown in Table 1 were produced.

<Evaluation>
The produced antireflection films 1 to 15 were evaluated as follows and the results are shown in Table 1.

(Measurement of object color L ^* a ^* b ^* value in reflection)
Using FE-3000 (manufactured by Otsuka Electronics Co., Ltd.), the value obtained by converting the spectral reflectance obtained by the refractive index and film thickness measurement methods to the reflectance every 5 nm in the wavelength range of 380 to 780 nm using the analysis software MCPD. Was used to calculate XYZ values specified by JIS Z 8701, and L ^* a ^* b ^* values specified by JIS Z 8729 were obtained.

(Measurement of object color L ^* a ^* b ^* value in transmission)
The transmittance T is calculated from the spectral transmittance obtained every 5 nm in the wavelength region of 380 to 780 nm of each film. In the formula for calculating the L ^* a ^* b ^* value of JIS Z 8729, P (λ) is the spectral distribution of the standard illuminant C light source for CIE colorimetry specified in JIS Z 8720, and y (λ) is the double field of view X Is a color matching function based on the Y, Z, and Z systems. Spectral transmittance τ (λ) was measured using Hitachi U-3310 type. Next, the L ^* a ^* b ^* value obtained from the tristimulus values in the 2-degree visual field XYZ system was calculated according to the method of JIS Z 8729.

(Measurement of surface resistivity)
The sample was conditioned at 23 ° C. and 55% RH for 24 hours, and measured using a Teraohm Meter Model VE-30 manufactured by Kawaguchi Electric Co., Ltd. The electrodes used for the measurement were measured by placing two electrodes (parts in contact with the sample at 1 cm × 5 cm) in parallel with an interval of 1 cm, contacting the sample with the electrodes, and multiplying the measured value by five times. The value was defined as the surface specific resistance value Ω / □.

  Next, the produced antireflection films 1 to 15 were incorporated into a polarizing plate and a liquid crystal display device according to the following procedure.

[Preparation of polarizing plate]
A polyvinyl alcohol film having a thickness of 120 μm was uniaxially stretched (temperature: 110 ° C., stretch ratio: 5 times). This was immersed in an aqueous solution composed of 0.075 g of iodine, 5 g of potassium iodide and 100 g of water for 60 seconds, and then immersed in an aqueous solution of 68 ° C. composed of 6 g of potassium iodide, 7.5 g of boric acid and 100 g of water. This was washed with water and dried to obtain a polarizing film.

  Subsequently, according to the following processes 1-5, the polarizing film, the said antireflection film, and the cellulose ester film of the back side were bonded together, and the polarizing plate was produced. As the polarizing plate protective film on the back surface side, a cellulose ester film having a retardation (measured at 590 nm, in-plane retardation Ro = 43 nm, retardation in the thickness direction Rt = 135 nm) was used as a polarizing plate.

  Step 1: Soaked in a 2 mol / L sodium hydroxide solution at 60 ° C. for 90 seconds, then washed with water and dried to obtain a saponified cellulose ester film on the side to be bonded to the polarizer.

  On the other hand, the surface of the anti-reflection layer side of the hard coat film on which the anti-reflection layer was formed was subjected to the above saponification treatment while applying a peelable polyethylene film and protecting it from alkali.

  Step 2: The polarizing film was immersed in a polyvinyl alcohol adhesive tank having a solid content of 2% by mass for 1 to 2 seconds.

  Step 3: Gently wipe off the excess adhesive adhered to the polarizing film in Step 2 and place it on the cellulose ester film treated in Step 1, so that the anti-reflection layer of the hard coat film is on the outside Laminated and placed.

Step 4: Excess adhesive and bubbles were removed from the end of the laminate of the antireflection film, the polarizing film, and the cellulose ester film sample laminated in Step 3 with a hand roller and bonded together. The pressure of the hand roller was 20 to 30 N / cm ² and the roller speed was about 2 m / min.

  Process 5: The sample which bonded the polarizing film produced in the process 4, the cellulose-ester film, and the antireflection film in the 80 degreeC dryer was dried for 2 minutes, and the polarizing plate was produced. Polarizing plates 1 to 15 were produced using the antireflection films 1 to 15, respectively.

[Production of liquid crystal display device]
A liquid crystal panel for viewing angle measurement was produced as follows, and the characteristics as a liquid crystal display device were evaluated. The results are shown in Table 1.

  The both-sided polarizing plates of the 15-inch display VL-150SD manufactured by Fujitsu were peeled off, and the prepared polarizing plates 1 to 15 were each bonded to the glass surface of the liquid crystal cell.

  At that time, the direction of bonding of the polarizing plate is such that the surface of the optical compensation film (retardation film) is on the liquid crystal cell side, and the absorption axis is in the same direction as the polarizing plate previously bonded. The liquid crystal display devices 1 to 15 were respectively produced.

<Evaluation>
(Evaluation of uneven coloring and tightness of black display)
Using the manufactured liquid crystal display device, the DVD “World Heritage Film Archives” (distributor: Shin Forest Co., Ltd.) was viewed by 10 evaluators. Ten points of personality were assigned and the overall score was evaluated according to the following criteria.

◎: 13 points or more ○: 7-12 points △: 3-7 points ×: 2 points or less

From the above table, in the L ^* a ^* b ^* values of the object color in reflection and transmission, the antireflection films 1, 2, 7 to 9 of the present invention in which the L ^* value, a ^* value, and b ^* value are within the present invention. Nos. 11 and 12 show that the coloring unevenness is not conspicuous with respect to the antireflection film of the comparative example, and the visibility and the black display are excellent when applied to the liquid crystal display device. It was found that the L ^* a ^* b ^* value of the object color in reflection and transmission can be adjusted by a film in which the constitution of the antireflection layer and the addition amount of the ultraviolet absorber are adjusted.

  Moreover, it turned out that the antireflection film 1, 2, 7-9, 11, 12 which concerns on this invention has a low surface specific resistance value, and is excellent also in the handleability.

Claims (14)

On at least one surface of a plastic substrate having a refractive index of 1.45 to 1.55 at a wavelength of 550 nm, film M (refractive index 1.55 to 1.75, film thickness 80 to 120 nm), film H (refractive An antireflection film in which an antireflection film is laminated in the order of a rate of 1.75 to 2.4 and a film thickness of 30 to 70 nm) and a film L (refractive index of 1.3 to 1.45, film thickness of 70 to 130 nm). An antireflective film characterized in that the object color in reflection and transmission under a standard illuminant C light source for CIE colorimetry is CIELAB color system and the values of L ^* , a ^* and b ^* are in the following ranges.
(I) Object color by reflection: L ^* value 15 or less
a ^* Value in the range of 0.5-5
b ^* value range of -20 to 5 (ii) object color by transmission: L ^* value 92 or more
a ^* Value in the range of 3-3
b ^* value range of 3-3 2. The reflection according to claim 1, wherein the object color in reflection and transmission under the CIE colorimetric standard illuminant C light source is CIELAB color system, and the values of L ^* , a ^* , and b ^* are in the following ranges. Prevention film.
(Iii) Object color due to reflection: L ^* value range of 1-8
a ^* value range of 0.6-3
b ^* value range of -17 to 3 (iv) object color by transmission: L ^* value range of 92 to 99.9
a ^* value -1.5 to 1.5 range
b ^* value -1.5 to 1.5 range The object color in transmission under the standard illuminant C light source for CIE colorimetry of the plastic substrate is CIELAB color system, and the values of L ^* , a ^* , b ^* are in the following ranges: 2. The antireflection film according to 2.
(V) Object color by transmission: L ^* value range of 96.9 to 97.4
a ^* value -0.3 to -0.1 range
b ^* value range from 0.4 to 1.0 The antireflection film according to claim 1, wherein the film M or the film H is a film containing conductive fine particles. The antireflection film according to claim 4, wherein the conductive fine particles are ITO or metal-doped zinc oxide. 6. The product dx is in the range of 30 to 80, where d (nm) is the film thickness of the antireflection film and x is the content ratio of the conductive fine particles. 2. The antireflection film according to item 1. The antireflection film according to claim 1, wherein the plastic substrate contains an ultraviolet absorber. The antireflection film according to claim 7, wherein the ultraviolet absorber is a benzotriazole ultraviolet absorber. The antireflection film according to claim 7 or 8, wherein the ultraviolet absorber is two or more kinds of benzotriazole ultraviolet absorbers. The antireflection film according to claim 1, further comprising a hard coat layer on the plastic substrate. The said plastic base material is a cellulose-ester film, and width is 1.4 m or more, The antireflection film of any one of Claims 1-10 characterized by the above-mentioned. A polarizing plate comprising the antireflection film according to claim 1. A display device comprising the antireflection film according to claim 1. A display device comprising the polarizing plate according to claim 12.