JP2003121606A - Antireflection film, polarizing plate and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antireflection film excellent in display quality which decreases both of the reflectance and colors in the reflected light at a low cost. SOLUTION: The antireflection film has at least one layer having a lower refractive index than that of a supporting body on the transparent supporting body. The average mirror face reflectance at 5 deg. incident angle of the film is <=0.5% in the wavelength region from 450 nm to 650 nm. When the colors of the reflected light for the light with 5 deg. incident angle from a CIE standard light source D65 in the wavelength region from 380 nm to 780 nm are expressed by the a* and b* values in the CIE1976L*a*b* color chart, the a* and b* values are in the ranges of -7<=a*<=7 and -10<=b*<=10, respectively.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an antireflection film, a polarizing plate using the same, and an image display apparatus using the same.

[0002]

2. Description of the Related Art Antireflection films are used in liquid crystal display devices (L
It is provided in various image display devices such as a CD), a plasma display panel (PDP), an electroluminescence display (ELD) and a cathode ray tube display (CRT). Anti-reflection film is also provided on the glasses and the lens of the camera. As the antireflection film, a multilayer film in which transparent thin films of metal oxide are laminated has been conventionally commonly used. The reason why a plurality of transparent thin films are used is to prevent reflection of light in a wavelength range as wide as possible in the visible range. The transparent thin film of metal oxide is formed by a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method, particularly a vacuum vapor deposition method or a sputtering method, which is a kind of physical vapor deposition method. A transparent thin film of a metal oxide has excellent optical properties as an antireflection film, but the film forming method by vapor deposition or sputtering has low productivity and is not suitable for mass production.

In place of the vapor deposition method, a method of forming an antireflection film by coating inorganic fine particles has been proposed. Japanese Examined Patent Publication (Kokoku) No. 60-59250 discloses an antireflection layer having fine pores and a particulate inorganic substance. The antireflection layer is formed by coating. The micropores are formed by activating gas treatment after coating the layer and allowing gas to escape from the layer. Japanese Patent Laid-Open No. 59-50401 discloses
Disclosed is an antireflection film in which a support, a high refractive index layer and a low refractive index layer are laminated in this order. The publication also discloses an antireflection film in which a medium refractive index layer is provided between a support and a high refractive index layer. The low refractive index layer is formed by coating a polymer or inorganic fine particles.

Japanese Unexamined Patent Publication No. 2-245702 discloses an antireflection film in which two or more kinds of ultrafine particles (for example, MgF ₂ and SiO ₂ ) are mixed and the mixing ratio is changed in the film thickness direction. There is. The refractive index is changed by changing the mixing ratio to obtain the same optical properties as the antireflection film having the high refractive index layer and the low refractive index layer described in JP-A-59-50401. ing. The ultrafine particles are adhered by SiO ₂ generated by thermal decomposition of ethyl silicate. In the thermal decomposition of ethyl silicate, carbon dioxide and water vapor are also generated by the combustion of ethyl part.
As shown in FIG. 1 of JP-A-2-245702, a gap is created between the ultrafine particles due to the separation of carbon dioxide and water vapor from the layer. Japanese Patent Laid-Open No. 5-13
No. 021 discloses filling the ultrafine particle gaps present in the antireflection film described in JP-A-2-245702 with a binder. JP-A-7-48
Japanese Patent No. 527 discloses an antireflection film containing an inorganic fine powder made of porous silica and a binder. Japanese Patent Application Laid-Open No. 11-6902 discloses a film having a three-layer antireflection film formed by wet coating, which uses a layer in which at least two inorganic fine particles are stacked in a low refractive index layer to contain microvoids. There is. A technique for providing an antireflection film that achieves both film strength and low reflectance at an inexpensive manufacturing cost by all-wet coating has been disclosed.

As means for imparting antiglare properties to the antireflection film by coating as described above, a method of coating an antireflection layer on a support having surface irregularities, or matte particles for forming surface irregularities is used. In addition to the method of adding to the coating liquid for forming the antireflection layer, an embossing method after the production of a smooth antireflection film as disclosed in JP-A-2000-275401 and 2000-275404. There is a method of forming a surface uneven structure by the above method.

[0006]

However, the antireflection film produced by the vapor deposition method or the sputtering method described above has an average reflectance of 0.4% or less in the wavelength region of 450 nm to 650 nm. The tint of light is strongly colored from red purple to blue purple, and there is a problem that the display quality is deteriorated when the reflected light source is behind.
On the other hand, the antireflection film manufactured by wet coating has a color tone of reflected light close to neutral,
The average reflectance exceeds 1%, and the antireflection performance is insufficient particularly in a use situation where external light is directly incident on the display surface. Example 24 of the above-mentioned JP-A-11-6902 describes that the average reflectance is 0.35% by wet coating, but when the tint of reflected light is calculated from the reflection spectrum, the tint of reflected light is It was found that the color became extremely strong red-purple, and even when a real sample was made and visually judged, it was strongly colored in red-purple, and there was also a problem that the display quality was impaired. Further, since the reflected light has a strong tint, the tint is greatly shifted due to a slight unevenness in the thickness of the antireflection layer,
There was a problem that it was visually detected as unevenness.

[0007]

The objects of the present invention have been achieved by the following means. (1) In an antireflection film having at least one low refractive index layer having a refractive index lower than that of a transparent support, a specular reflectance of 450 nm to 6 at 5 degrees incidence
The average value in the wavelength region up to 50 nm is 0.5% or less, and the CI in the wavelength region from 380 nm to 780 nm
E The tint of the specular reflection light with respect to the 5 degree incident light of the standard light source D65 is such that the a * and b * values of the CIE1976L * a * b * color space are −7 ≦ a * ≦ 7 and −10 ≦ b *, respectively. ≤10
The antireflection film is characterized by being within the range. (2) The reflection according to (1), wherein in the antireflection film, a * and b * values are in the range of 0 ≦ a * ≦ 5 and −7 ≦ b * ≦ 0, respectively. Prevention film. (3) The antireflection film as described in (1) or (2), wherein the average value of the specular reflectance at 5 degrees incidence in the wavelength region from 450 nm to 650 nm is 0.4% or less. Anti-reflection film. (4) The antireflection film as described in (1) or (2), wherein the average value of the specular reflectance at 5 degree incidence in the wavelength region from 450 nm to 650 nm is 0.3% or less. Anti-reflection film. (5) Each layer of the antireflection film is formed by coating a coating composition containing a film-forming solute and at least one solvent, drying the solvent, and curing with heat and / or ionizing radiation. The antireflection film as described in any one of (1) to (4). (6) Between the low refractive index layer and the transparent support, in order from the low refractive index layer side, a high refractive index layer having a higher refractive index than the support, and between the support and the high refractive index layer. The antireflection film as described in (5), wherein substantially three layers having different refractive indices, that is, a medium refractive index layer having a refractive index, are formed. (7) In the antireflection film, the design wavelength λ
(= 500 nm), the medium refractive index layer has the following formula (I),
The high refractive index layer is represented by the following formula (II), and the low refractive index layer is represented by the following formula (II).
The antireflection film according to claim 6, which satisfies each of I). lλ / 4 × 0.80 <n1d1 <lλ / 4 × 1.00 (I) mλ / 4 × 0.75 <n2d2 <mλ / 4 × 0.95 (II) nλ / 4 × 0.95 <n3d3 < nλ / 4 × 1.05 (III) (wherein, 1 is 1, n1 is the refractive index of the medium refractive index layer, and d1 is the layer thickness (nm) of the medium refractive index layer. , M is 2, n2 is the refractive index of the high refractive index layer, and d2 is the layer thickness (nm) of the high refractive index layer,
(n is 1, n3 is the refractive index of the low refractive index layer, and d3 is the layer thickness (nm) of the low refractive index layer) (8) The refractive index is 1.45 to 1.55 N1 is 1.60 to 1.65 and n2 is 1.85 to the transparent support.
The antireflection film as described in (7), wherein 1.95 and n3 have a refractive index of 1.35 to 1.45. (9) For a transparent support having a refractive index of 1.55 to 1.65, n1 is 1.65 to 1.75 and n2 is 1.85.
The antireflection film as described in (7), wherein 2.05 and n3 have a refractive index of 1.35 to 1.45. (10) The antireflection film as described in any one of (7) to (9), wherein the low refractive index layer of the antireflection film is composed of a heat- or ionizing radiation-curable fluorine-containing curable resin. . (11) The high refractive index layer of the antireflection film comprises T
Ultrafine particles containing at least one metal oxide selected from oxides of i, Zr, In, Zn, Sn and Sb, anionic dispersant, curable resin having a trifunctional or higher functional polymerizable group, and polymerization (9) The antireflection according to any one of (7) to (9), which is formed by applying a coating composition containing an initiator, drying a solvent, and curing with a heat and / or ionizing radiation. the film. (12) The antireflection film as described in (10), wherein the low refractive index layer of the antireflection film has a dynamic friction coefficient of 0.15 or less and a contact angle of pure water of 100 degrees or more. (13) The antireflection film as described in any one of (1) to (12), which has at least one hard coat layer between the low refractive index layer and the transparent support. (14) At least one forward scattering layer is provided between the low refractive index layer and the transparent support,
The antireflection film as described in any one of (1) to (13). (15) Wavelengths from 380 nm to 780 n at arbitrary two places 10 cm apart in the TD direction or the MD direction
The tint unevenness of the specular reflection light with respect to the 5 degree incident light of the CIE standard light source D65 in the m range is CIE1976L * a *
The ΔEab * value in the b * color space is less than 2, and the antireflection film as described in any one of (1) to (14). (16) The vertical peeling charge amount measured with respect to either triacetyl cellulose or polyethylene terephthalate at room temperature and normal humidity is -200 pc (pico coulomb) / c.
m ² to +200 pc (pico coulomb) / cm ² and a surface resistance value of 1 × 10 ¹¹ Ω / □ or more (1) to (15) The antireflection film as described in the item. (17) A polarizing plate in which two surface protective films are attached to the front surface and the back surface of a polarizer, and after the low refractive index layer of the antireflection film according to any one of (1) to (16) is formed. By immersing in an alkaline solution at least once,
A polarizing plate, characterized in that an antireflection film obtained by saponifying the back surface of the film is used as at least one surface protection film. (18) A polarizing plate in which two surface protective films are bonded to the front surface and the back surface of a polarizer, and the low refractive index layer of the antireflection film according to any one of (1) to (16) is formed. Before or after forming the surface, an alkaline solution is applied to the surface of the antireflection film opposite to the surface on which the low refractive index layer is formed, and heating, washing with water and / or neutralization is performed to remove only the back surface of the film. A polarizing plate comprising a saponified antireflection film as a surface protective film on at least one side. (19) A film other than the antireflection film in the surface protection film is an optical compensation film having an optical compensation layer including an optically anisotropic layer on the surface of the surface protection film opposite to the polarizer, The optically anisotropic layer is a layer having a negative birefringence composed of a compound having a discotic structural unit, the disc surface of the discotic structural unit is inclined with respect to the surface protective film surface, and The polarizing plate according to (17) or (18), wherein the angle formed by the disk surface of the tick structure unit and the surface of the surface protective film changes in the depth direction of the optically anisotropic layer. (20) TN, STN, VA, IP having at least one polarizing plate according to any one of (17) to (19)
A transmissive type, a reflective type, or a semi-transmissive type liquid crystal display device of S and OCB modes. (21) A transmissive or semi-transmissive liquid crystal display device having at least one polarizing plate according to any one of (17) to (19), comprising a polarizing plate and a backlight on the side opposite to the viewing side. A liquid crystal display device, characterized in that a polarization separation film having a polarization selection layer is arranged between the two. (22) The antireflection film as described in any one of (1) to (16), wherein the transparent support is a polyethylene terephthalate film or a polyethylene naphthalate film. (23) The transparent protective film on the side opposite to the antireflection film of the polarizing plate described in (17) or (18) has λ /
A transmissive or semi-transmissive liquid crystal device having four plates. (24) λ / on the transparent protective film on the side opposite to the antireflection film of the polarizing plate described in (17) or (18).
An organic EL display device having four plates arranged.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The basic structure of the antireflection film of the present invention will be described with reference to the drawings.

[Formation of Antireflection Film] FIG. 1 is a schematic sectional view showing a basic layer structure of the antireflection film used in the present invention. It has a layer structure of a transparent support (1), a hard coat layer (2), a medium refractive index layer (3), a high refractive index layer (4), and a low refractive index layer (5) in this order. In such an antireflection film having a three-layer structure, the optical film thickness of each of the medium refractive index layer, the high refractive index layer, and the low refractive index layer, that is, the product of the refractive index and the film thickness, with respect to the design wavelength λ around nλ / 4,
Alternatively, it is preferable that it is a multiple thereof.
-50401. However,
In order to realize the low reflectance and the reflectance characteristic in which the tint of reflected light is reduced, the design wavelength λ (= 500 n
For m), the medium refractive index layer needs to satisfy the following formula (I), the high refractive index layer needs to satisfy the following formula (II), and the low refractive index layer needs to satisfy the following formula (III).

[0010]   lλ / 4 × 0.80 <n1d1 <lλ / 4 × 1.00 (I)

[0011]   mλ / 4 × 0.75 <n2d2 <mλ / 4 × 0.95 (II)

[0012]   nλ / 4 × 0.95 <n3d3 <nλ / 4 × 1.05 (III)

Where l is 1, n1 is the refractive index of the medium refractive index layer, and d1 is the layer thickness (n
m), m is 2, n2 is the refractive index of the high refractive index layer, and d2 is the layer thickness (nm) of the high refractive index layer, n is 1 and n3 is low refractive index. Is the refractive index of the index layer,
And d3 is the layer thickness (nm) of the low refractive index layer. Furthermore, for example, triacetyl cellulose (refractive index: 1.4
For a transparent support having a refractive index of 1.45 to 1.55 such as 9), n1 is 1.60 to 1.65, n2 is 1.85 to 1.95, and n3 is 1.35. Must have a refractive index of ˜1.45, for example a refractive index of 1.5, such as polyethylene terephthalate (refractive index: 1.66).
For a transparent support of 5 to 1.65, n1 is 1.6
5 to 1.75, n2 is 1.85 to 2.05, and n3 is 1.
It should have a refractive index of 35 to 1.45. When the material for the medium-refractive index layer or high-refractive index layer having the above-mentioned refractive index cannot be selected, it is equivalent to combining a layer having a higher refractive index and a layer having a lower refractive index than the set refractive index. It is well known that the principle of a film can be used to form a layer that is substantially optically equivalent to a medium-refractive index layer or a high-refractive index layer having a set refractive index, and also for realizing the reflectance characteristics of the present invention. Can be used. The “substantially three layers” of the present invention means
It also includes an antireflection layer composed of four layers and five layers using such an equivalent film and having different refractive indexes.

The reflectance characteristic of the present patent achieved by the above-mentioned layer structure can achieve both low reflection and reduction of the tint of reflected light, and therefore, for example, on the outermost surface of a liquid crystal display device. When applied, a display device having unprecedented high visibility can be obtained. Since the average value of the specular reflectance at wavelengths of 5 degrees from 450 nm to 650 nm is 0.5% or less, the reduction in visibility due to the reflection of external light on the display device surface is prevented to a sufficient level. it can. The average value is preferably 0.4% or less, more preferably 0.3% or less. Also, the wavelength is 380 nm
From 780 nm to 780 nm, the tint of specular reflection light with respect to the 5 degree incident light of the CIE standard light source D65 is CIE1976
The a * and b * values of the L * a * b * color space are −7 ≦ a.
By setting it within the range of * ≦ 7 and −10 ≦ b * ≦ 10, the tint of reddish purple to bluish purple reflected light, which has been a problem in the conventional multilayer antireflection film, is further reduced. ≤
By setting a * ≦ 5 and −7 ≦ b * ≦ 0, it is significantly reduced, and when applied to a liquid crystal display device, outside light with high brightness such as a fluorescent lamp in a room is slightly reduced. The color tones when reflected in the image is neutral, which is not a concern. Specifically, a
When it is *> 7, the redness is strong, and when it is a * <-7, the cyan taste is strong, which is not preferable. When b * <-7, the bluish color is strong,
When b *> 0, the yellowness becomes strong, which is not preferable. The specular reflectance and the tint were measured by attaching the adapter ARV-474 to a spectrophotometer V-550 (manufactured by JASCO Corporation), and measuring 3
In the wavelength region of 80 to 780 nm, the specular reflectance at an exit angle of -5 degrees at an incident angle of 5 ° was measured to be 450 to 65.
The antireflection property can be evaluated by calculating the average reflectance at 0 nm. Furthermore, from the measured reflection spectrum,
CIE1976 L * a * b * L * of color space representing the tint of specularly reflected light with respect to the 5 degree incident light of the CIE standard light source D65
Values, a * values, and b * values can be calculated to evaluate the tint of reflected light.

Further, since the tint of the reflected light is greatly reduced as described above, the tint of the reflected light caused by the film thickness unevenness of the antireflection layer is also greatly reduced. That is, the allowable range of film thickness unevenness is expanded, the manufacturing yield is increased, and the cost can be further reduced. Quantitatively, T
D direction (direction orthogonal to the longitudinal direction of the support) or MD
Can be represented by the tint unevenness of the specular reflection light with respect to the 5 degree incident light of the CIE standard light source D65 in the wavelength range of 380 nm to 780 nm at two arbitrary positions 10 cm apart in the direction (longitudinal direction of the support), and CIE1976L * a
The ΔEab * value in the * b * color space is preferably less than 2, and less than 1.5 is more preferable because human eyes cannot detect unevenness completely.

The antireflection film of the present invention has a vertical peel charge of -200 pc (pico coulomb) / cm measured at room temperature and normal humidity for either triacetyl cellulose (TAC) or polyethylene terephthalate (PET).
It is preferably ² to +200 pc (pico coulomb) / cm ² from the viewpoint of dust resistance. More preferably -10
It is 0 pc / cm to +100 pc / cm ² , more preferably −50 pc / cm ² to +50 pc / cm ² , and most preferably 0 pc / cm ² . Here, the unit pc (pico coulomb) is 10 ⁻¹² coulomb. More preferably, the vertical peeling charge measured at room temperature of 10% RH is −100 pc / cm ² to +100 pc / cm ^2.
And more preferably −50 pc / cm ² to +50.
a pc / cm ^2, and most preferably 0pc / cm ^2.

The method of measuring the vertical peeling charge is as follows. The measurement sample is left in advance for 2 hours or more under the environment of measurement temperature and humidity. The measuring device is composed of a table on which a sample to be measured is placed and a head which holds the film of the other party and can press and peel the sample repeatedly from above, and an electrometer for measuring the amount of charge is connected to this head. Place the anti-reflection film to be measured on the table and put it on the head.
Wear AC or PET. After destaticizing the measurement portion, the head is pressed against the measurement sample and peeling is repeated, and the charge values at the first peeling and the fifth peeling are read and averaged. This is repeated for 3 samples with different samples, and the average of all is taken as the vertical peeling charge.

Depending on the type of the mating film or the sample to be measured, it may be positively charged or negatively charged, but the problem is the magnitude of the absolute value. Further, generally, the absolute value of charging becomes larger in an environment of low humidity. The absolute value of the antireflection film of the present invention is also small.

The antireflection film of the present invention is excellent in dustproofness because the absolute value of the vertical peeling charge at room temperature and normal humidity and room temperature 10% RH is small. The value of the vertical peeling charge is set within the above range by adjusting the ratio of various elements on the surface of the antireflection film.

The surface resistance of the antireflection film of the present invention is 1 × 10 ¹¹ Ω / □ or more, preferably 1 × 10 ¹² Ω /.
□ Above. The method for measuring the surface resistance value is the circular electrode method described in JIS. That is, the current value one minute after the voltage application is read to obtain the surface resistance value (SR). In the present invention, it is necessary to reduce the surface resistance value, for example, 1 × 10 ¹⁰ Ω
The idea is fundamentally different from the method of improving the dust-proof property (prevention of dust adhesion) by making it / □ or less. This method is not used because the image display quality is deteriorated. In the present invention, the absolute value of vertical peeling electrification is made small by the above-mentioned method. Therefore, it is not necessary to make the surface resistance value small, and the surface resistance value is 1 × 10.
It can be set to ¹¹ Ω / □ or more and the image display quality does not deteriorate.

As the transparent support used in the antireflection film of the present invention, it is preferable to use a plastic film. Examples of materials for the plastic film include cellulose ester (eg, triacetyl cellulose, diacetyl cellulose, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose, nitrocellulose), polyamide, polycarbonate, polyester (eg, polyethylene terephthalate, polyethylene naphthalate). , Poly-1,4-cyclohexanedimethylene terephthalate, polyethylene-1,2-diphenoxyethane-4,4'-dicarboxylate, polybutylene terephthalate), polystyrene (eg, syndiotactic polystyrene), polyolefin (eg, Polypropylene, polyethylene, polymethylpentene), polysulfone, polyethersulfone, polyarylate, polyetherimide, polymethylmethene Includes tacrylate and polyetherketone. Especially liquid crystal display devices and organic EL
When the antireflection film of the present invention is used as one side of the surface protective film of a polarizing plate for use in a display device or the like, triacetyl cellulose is preferably used. As a triacetyl cellulose film, TAC-TD80
Known materials such as U (manufactured by Fuji Photo Film Co., Ltd.) and materials disclosed in Published Technical Report No. 2001-1745 are preferably used. Further, when it is used by being stuck to a glass substrate or the like for use in a flat CRT or PDP, polyethylene terephthalate or polyethylene naphthalate is preferable. The light transmittance of the transparent support is 80%
It is preferably at least 80%, more preferably at least 86%. The haze of the transparent support is preferably 2.0% or less, more preferably 1.0% or less. The transparent support preferably has a refractive index of 1.4 to 1.7. The thickness of the transparent support of the present invention is not particularly limited, but is preferably 30 to 150 μm, and 40 to
130 μm is more preferable, and 70 to 120 μm is still more preferable.

The medium refractive index layer and the high refractive index layer are formed by coating a coating composition containing inorganic fine particles having a high refractive index, a heat or ionizing radiation curable monomer, an initiator and a solvent, drying the solvent, heat and / or heat. Alternatively, it is formed by curing with ionizing radiation. As the inorganic fine particles, Ti, Zr,
An oxide composed of at least one metal oxide selected from oxides of In, Zn, Sn, and Sb is preferable. The medium-refractive index layer and the high-refractive index layer thus formed are excellent in scratch resistance and adhesion as compared with those obtained by coating and drying a polymer solution having a high refractive index. In order to secure the dispersion stability and the film strength after curing, etc., JP-A-11-1537
It is preferable that the coating composition contains a polyfunctional (meth) acrylate monomer and an anionic group-containing (meth) acrylate dispersant, as described in JP-A No. 03, JP No. 6210858B1 and the like.

The average particle size of the inorganic fine particles is 1 to 100 nm as the average particle size when measured by the Coulter counter method.
Is preferred. If it is 1 nm or less, the specific surface area is too large, and the stability in the dispersion is poor, which is not preferable. When it is 100 nm or more, visible light is scattered due to the difference in refractive index with the binder, which is not preferable. The haze of the high refractive index layer and the medium refractive index layer is preferably 3% or less, more preferably 1% or less, and 0.
It is more preferably 5% or less.

A fluorine-containing compound which is cured by heat or ionizing radiation is used for the low refractive index layer. The coefficient of dynamic friction of the cured product is preferably 0.03 to 0.15, and the contact angle with pure water is preferably 100 to 120 degrees. If the coefficient of kinetic friction is higher than 0.15, scratches are likely to occur when the surface is rubbed, which is not preferable. If the contact angle to pure water is less than 100 degrees, fingerprints, oil stains and the like are likely to adhere, which is not preferable from the viewpoint of antifouling property. As the curable fluorine-containing polymer compound, a perfluoroalkyl group-containing silane compound (for example, (heptadecafluoro-1,1,2,
In addition to (2-tetradecyl) triethoxysilane) and the like, a fluorine-containing copolymer having a fluorine-containing monomer and a monomer for imparting a crosslinkable group as a constituent unit can be given. Specific examples of the fluorine-containing monomer unit include, for example, fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoro-2,2).
-Dimethyl-1,3-dioxole, etc.), partially or fully fluorinated alkyl ester derivatives of (meth) acrylic acid (for example, biscoat 6FM (Osaka Organic Chemical) or M
-2020 (manufactured by Daikin Co., Ltd.) and completely or partially fluorinated vinyl ethers and the like. Among these, hexafluoropropylene is particularly preferable from the viewpoint of low refractive index and easy handling of the monomer. As a monomer for providing a crosslinkable group, in addition to a (meth) acrylate monomer having a crosslinkable functional group in advance in the molecule such as glycidyl methacrylate, a monomer having a carboxyl group, a hydroxyl group, an amino group, a sulfonic acid group, etc. ) Acrylate monomers (eg (meth) acrylic acid, methylol (meth))
Acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate and the like). The latter is capable of introducing a crosslinked structure after copolymerization.
It is disclosed in Japanese Patent Laid-Open No. 388 and Japanese Patent Laid-Open No. 10-147739 and is particularly preferable.

Further, not only a polymer having the above-mentioned fluorine-containing monomer as a constitutional unit but also a copolymer with a monomer not containing a fluorine atom may be used. The monomer unit that can be used in combination is not particularly limited, and examples thereof include olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic acid esters (methyl acrylate,
Methyl acrylate, ethyl acrylate, acrylic acid 2-
Ethylhexyl), methacrylic acid esters (methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, vinyltoluene, α-methylstyrene, etc.), vinyl ethers (methyl vinyl ether) Etc.), vinyl esters (vinyl acetate, vinyl propionate, vinyl cinnamate, etc.), acrylamides (N-tert-butyl acrylamide, N-cyclohexyl acrylamide, etc.), methacrylamides, acrylonitrile derivatives, and the like. JP-A-10-25388 and JP-A-10-147.
It is disclosed by Japanese Patent No. 739.

Further, as a means for lowering the dynamic friction coefficient in order to impart scratch resistance, it is possible to introduce a copolymerized unit capable of improving slipperiness. A method for introducing a polydimethylsiloxane segment into the main chain is disclosed in JP-A-11-228.
It is disclosed in Japanese Patent No. 631 and is particularly preferable.

The fluorine-containing resin used for forming the low refractive index layer is preferably added with ultrafine Si oxide particles in order to impart scratch resistance. From the viewpoint of antireflection property, the lower the refractive index, the more preferable, but as the refractive index of the fluororesin is lowered, the scratch resistance deteriorates. Therefore, by optimizing the refractive index of the fluorine-containing resin and the addition amount of the Si oxide ultrafine particles, it is possible to find the best balance between scratch resistance and low refractive index. As Si oxide ultrafine particles,
The silica sol dispersed in a commercially available organic solvent may be added to the coating composition as it is, or various commercially available silica powders may be dispersed in an organic solvent and used.

The antireflection film may be further provided with a hard coat layer, a forward scattering layer, an antistatic layer, an undercoat layer and a protective layer. The hard coat layer is provided to impart scratch resistance to the transparent support. The hard coat layer also has a function of enhancing the adhesion between the transparent support and the layer above it. The hard coat layer was obtained by adding an inorganic filler such as silica or alumina to a composition prepared by dissolving a polyfunctional acrylic monomer, urethane acrylate, an oligomer such as epoxy acrylate, or a polymerization initiator in a solvent, if necessary. It is preferably formed by coating the coating composition, drying the solvent, and curing with heat and / or ionizing radiation. Details will be described later. The thickness of the hard coat layer is 1 to 30
The thickness is preferably μm, more preferably 1 to 20 μm, most preferably 2 to 15 μm. The pencil hardness of the hard coat layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher. The refractive index of the hard coat layer is preferably in the range of 1.45 to 2.0, and 1.5 to 1.
The range of 8 is more preferable. The hard coat layer can be formed as a layer composed of an inorganic compound mainly containing silicon dioxide, a layer composed of an organic compound such as a polymer having a saturated hydrocarbon or polyether as a main chain, or a hybridized layer of an inorganic / organic compound. . A layer made of a polymer having a saturated hydrocarbon as a main chain is particularly preferable. The polymer is preferably crosslinked. The polymer having a saturated hydrocarbon as a main chain is preferably obtained by a polymerization reaction of an ethylenically unsaturated monomer. In order to obtain a crosslinked binder polymer, it is preferable to use a monomer having two or more ethylenically unsaturated groups.

Examples of the monomer having two or more ethylenically unsaturated groups include esters of polyhydric alcohol and (meth) acrylic acid (eg, ethylene glycol di (meth) acrylate, 1,4-dichlorohexanediacrylate). , Pentaerythritol tetra (meth) acrylate), pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta ( (Meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3-cyclohexanetetramethacrylate, polyurethane polyacrylate, polyester polyacrylate), vinylbenzene and its Derivatives (eg 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1,4-divinylcyclohexanone), vinyl sulfone (eg divinyl sulfone), acrylamide (eg methylenebisacrylamide) and methacryl Includes amide. The polymer having a polyether as the main chain is preferably synthesized by a ring-opening polymerization reaction of a polyfunctional epoxy compound. These monomers having an ethylenically unsaturated group need to be cured by a polymerization reaction by ionizing radiation or heat after coating.

Instead of or in addition to the monomer having two or more ethylenically unsaturated groups, a crosslinked structure may be introduced into the binder polymer by the reaction of the crosslinkable group.
Examples of the crosslinkable functional group include an isocyanate group, an epoxy group, an aziridine group, an oxazoline group, an aldehyde group, a carbonyl group, a hydrazine group, a carboxyl group, a methylol group and an active methylene group. Vinyl sulfonic acid, acid anhydride, cyanoacrylate derivative, melamine,
Etherified methylols, esters and urethanes, and metal alkoxides such as tetramethoxysilane can also be used as monomers for introducing a crosslinked structure. You may use the functional group which shows crosslinkability as a result of a decomposition reaction like a block isocyanate group. Further, in the present invention, the cross-linking group is not limited to the above compound and may be one which exhibits reactivity as a result of decomposition of the above functional group. It is necessary to crosslink the compound having these crosslinkable groups with heat after coating.

Further, inorganic fine particles may be added to the hard coat layer in order to control the refractive index and enhance the hardening strength of the film. The average particle size of the inorganic fine particles is 0.00
1 to 0.5 μm is preferable, and 0.001 to 0.2
Those having a size of μm are particularly preferable. As the inorganic fine particles, silicon dioxide particles, titanium dioxide particles, aluminum oxide particles,
Tin oxide particles, calcium carbonate particles, barium sulfate particles,
Examples thereof include talc, kaolin and calcium sulfate particles, with silicon dioxide particles, titanium dioxide particles and aluminum oxide particles being particularly preferred. The amount of the inorganic fine particles added is preferably 10 to 90% by mass of the total mass of the hard coat layer, more preferably 20 to 80% by mass, and 30
-60 mass% is especially preferable.

The forward scattering layer is provided in order to provide the effect of improving the viewing angle when the viewing angle is tilted vertically and horizontally when applied to a liquid crystal display device. By dispersing fine particles having different refractive indexes in the hard coat layer, the hard coat layer can also serve as a hard coat function.

In the case where the multilayer antireflection film obtained by wet coating the coating composition of the present invention is used to obscure the background reflection due to surface irregularities and to impart antiglare properties, matte particles which are generally used are contained. Rather than forming an antireflection layer on a layer with surface irregularities, forming the surface irregularity structure after forming the antireflection layer by an embossing method improves the film thickness uniformity and improves the antireflection performance. Therefore, it is preferable.

Each layer of the antireflection film has a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method, a gravure coating method, a microgravure method and an extrusion coating method (US Pat. No. 2,681,294). ), It can be formed by coating. The microgravure method and the gravure method are preferable from the viewpoint of eliminating drying unevenness by minimizing the wet coating amount, and the gravure method is particularly preferable from the viewpoint of film thickness uniformity in the width direction. Two or more layers may be applied simultaneously. For the simultaneous coating method, see US Pat.
61791, 2941898, and 3508947.
Nos. 3526528 and Yuji Harasaki,
Coating Engineering, page 253, Asakura Shoten (1973).

When the antireflection film of the present invention is used as one side of the surface protective film of a polarizer, the surface of the transparent support opposite to the surface on which the antireflection layer is formed may be saponified with alkali. is necessary. Specific means for the alkali saponification treatment can be selected from the following two. (1) is superior in that it can be processed in the same process as a general-purpose triacetyl cellulose film, but since the antireflection film surface is saponified, the surface is alkali-hydrolyzed and the film deteriorates. A problem may be that when the liquid remains, it becomes dirty. In that case, although it is a special process, (2) is excellent. (1) After the antireflection layer is formed on the transparent support, the back surface of the film is saponified by immersing the film in an alkaline solution at least once. (2) Before or after forming the antireflection layer on the transparent support, an alkaline liquid is applied to the surface of the antireflection film opposite to the surface on which the antireflection film is formed, and heating, washing and / or middle By soaking, only the back surface of the film is saponified.

Examples of the polarizer include iodine-based polarizers, dye-based polarizers using dichroic dyes, and polyene-based polarizers. Generally, a polyvinyl alcohol film (hereinafter referred to as PVA) is preferably used as the iodine-based polarizer and the dye-based polarizer. PVA is usually saponified polyvinyl acetate, but modified PVA can also be used. A polarizing film is obtained by dyeing PVA. As an example of dyeing, any method such as a method of immersing a PVA film in an iodine-potassium iodide aqueous solution, coating or spraying with iodine or a dye solution can be used. PV
In the process of producing a polarizing film by stretching A, it is preferable to use an additive that crosslinks PVA, such as boric acid. The transmittance of the polarizing plate at the wavelength of 550 nm is
It is preferably in the range of 30 to 50%, and more preferably in the range of 35 to 50%. The degree of polarization is
For light having a wavelength of 550 nm, it is preferably in the range of 90 to 100%, more preferably in the range of 95 to 100%, and most preferably in the range of 99 to 100%.

The antireflection film of the present invention, when used as one side of a surface protective film of a polarizer, is twisted nematic (TN), super twisted nematic (STN), vertical alignment (VA), in-plane switching (IPS). ), An optically compensated bend cell (OCB), and other modes of transmission type, reflection type, or semi-transmission type liquid crystal display device. When used in a transmissive or semi-transmissive liquid crystal display device, it is used in combination with a commercially available brightness enhancement film (polarization separation film having a polarization selection layer, such as D-BEF manufactured by Sumitomo 3M Ltd.). Thus, a display device with higher visibility can be obtained. Further, in a transmissive type, a reflective type, and a semi-transmissive type liquid crystal display device, when a front plate such as an acrylic plate is arranged on the entire surface of the liquid crystal cell via air, not only the polarizing plate on the liquid crystal cell surface side, It is preferable to stick the inner surface and / or the outer surface of the front plate via an adhesive or the like, since reflection at the interface can be reduced. Also, by combining with a λ / 4 plate, it can be used as a reflective or semi-transmissive LCD or a surface protective plate for an organic EL display. Furthermore, by forming the antireflection layer of the present invention on a transparent support such as PET or PEN, it can be used in a PDA, a surface protection plate of a mobile phone, a touch panel, a plasma display panel (PDP) or a cathode ray tube display (CRT). It can be applied to various image display devices.

[0038]

The present invention will be described below with reference to examples, but the present invention is not limited to these. (Preparation of coating liquid A for hard coat layer) Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku Co., Ltd.)
306 parts by mass) was dissolved in a mixed solvent of 16 parts by mass of methyl ethyl ketone and 220 parts by mass of cyclohexanone. A photopolymerization initiator (IRGACURE 90
7.5 parts by mass, manufactured by Ciba-Geigy Co., Ltd.) was added and stirred until dissolved, and then 450 parts by mass of MEK-ST.
(S with an average particle size of 10 to 20 nm and a solid content concentration of 30% by mass)
A methyl ethyl ketone dispersion of io ₂ sol, manufactured by Nissan Kagaku Co., Ltd. was added and stirred to obtain a mixture having a pore size of 3 μm.
Was filtered through a polypropylene filter (PPE-03) to prepare a coating liquid A for hard coat layer.

(Preparation of Hard Coat Layer Coating Liquid B) 1000 parts by mass of the above hard coat layer coating liquid A (refractive index after solvent drying and UV curing: 1.51) had an average particle size of 1.
Particles with forward scattering property made of 3 μm cross-linked polystyrene (SX-130H, refractive index: 1.61, Soken Chemical Co., Ltd.)
(Manufactured) 150 parts by mass is added, and 10 parts are added with an air dispersion.
The mixture was stirred for a minute to obtain a mixture, and the mixture was filtered through a polypropylene filter (PPE-03) having a pore size of 3 μm to prepare a coating solution B for hard coat layer having forward scattering property.

(Preparation of coating liquid C for hard coat layer) 91 parts by mass of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.), zirconium oxide having a particle size of about 30 nm 218 parts by mass of a hard coat coating liquid containing a fine particle dispersion (Desolite Z-7401, manufactured by JSR Corporation) was dissolved in 52 parts by mass of a mixed solvent of methyl ethyl ketone / cyclohexanone = 54/46% by mass. To the obtained solution, 10 parts by mass of a photopolymerization initiator (IRGACURE 907, manufactured by Ciba Fine Chemicals Co., Ltd.) was added, and the mixture was stirred to obtain a mixture, which was filtered with a polypropylene filter (PPE-03) having a pore size of 3 μm to obtain a hard solution. Coating liquid C for coating layer
Was prepared.

(Preparation of titanium dioxide dispersion) Ultrafine titanium dioxide particles (TTO-55B, manufactured by Ishihara Techno Co., Ltd.) 3
0 parts by weight, dimethylaminoethyl acrylate (DMA
1 part by mass of EA, manufactured by Kojin Co., Ltd., 6 parts by mass of a phosphate group-containing anionic dispersant (KAYARAD PM-21, manufactured by Nippon Kayaku Co., Ltd.) and 63 parts by mass of cyclohexanone were coultered with a sand grinder. The titanium dioxide dispersion was prepared by dispersing until the average particle size measured by the method reached 42 nm.

(Preparation of Coating Solution A for Medium Refractive Index Layer) To 75 parts by mass of cyclohexanone and 19 parts by mass of methyl ethyl ketone, 0.11 parts by mass of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) and a photosensitizer (Kayacure) are added. 0.04 parts by mass of DETX, manufactured by Nippon Kayaku Co., Ltd. was dissolved. Further, 3.1 parts by mass of titanium dioxide dispersion and a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA,
2.1 parts by mass of Nippon Kayaku Co., Ltd. was added, the mixture was stirred at room temperature for 30 minutes, and then filtered through a polypropylene filter (PPE-03) having a pore size of 3 μm to prepare a coating liquid for medium refractive index layer. .

(Preparation of Coating Solution B for Medium Refractive Index Layer) 750 parts by mass of cyclohexanone and 190 parts by mass of methyl ethyl ketone, 1.2 parts by mass of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) and a photosensitizer (Kayacure). D
0.4 parts by mass of ETX, manufactured by Nippon Kayaku Co., Ltd. was dissolved.
Furthermore, 105 parts by mass of titanium dioxide dispersion and 21 parts by mass of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) were added, and the mixture was stirred at room temperature for 30 minutes, and then the pore size was 3 μm. Polypropylene filter (P
It filtered with PE-03) and the coating liquid B for middle refractive index layers was prepared.

(Preparation of coating liquid for high refractive index layer) 54 parts by mass of cyclohexanone and 18 parts by mass of methyl ethyl ketone, 0.13 parts by mass of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) and a photosensitizer (Kayacure D).
0.04 parts by mass of ETX and manufactured by Nippon Kayaku Co., Ltd. were dissolved. Furthermore, 26.4 parts by mass of titanium dioxide dispersion and a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPH
1.6 parts by mass of A, manufactured by Nippon Kayaku Co., Ltd., and added at room temperature to 3
After stirring for 0 minutes, the mixture was filtered through a polypropylene filter (PPE-03) having a pore size of 3 μm to prepare a coating liquid for high refractive index layer.

(Preparation of coating liquid for low refractive index layer) Refractive index 1.
42, a 6 mass% methyl ethyl ketone solution of a heat-crosslinkable fluoropolymer (JN-7228, JS
R (manufactured by R Co., Ltd.) was subjected to solvent substitution to obtain a polymer solution containing a solid content of 10% by mass in a mixed solvent of 85% by mass of methyl isobutyl ketone and 15% by mass of 2-butanol. In 70 parts by mass of this polymer solution, MEK-ST (average particle size: 10 to 20 nm, solid content: 30% by mass of SiO ₂
Methyl ethyl ketone dispersion of sol, manufactured by Nissan Chemical Co., Ltd.
10 parts by mass, 42 parts by mass of methyl isobutyl ketone and 28 parts by mass of cyclohexanone were added, and after stirring,
Polypropylene filter with a pore size of 3 μm (PPE-0
It filtered by 3) and prepared the coating liquid for low refractive index layers.

[Example 1] (Preparation of antireflection film) A triacetyl cellulose film having a thickness of 80 µm (TAC-TD80U, manufactured by Fuji Photo Film Co., Ltd., refractive index: 1.47) was coated with the above hard coat. The layer coating liquid A was applied using a gravure coater and dried at 100 ° C. for 2 minutes. Next, it is irradiated with ultraviolet rays to cure the coating layer and hard coat layer (refractive index:
1.51, film thickness: 6 μm) was formed. Subsequently, the coating liquid A for the medium refractive index layer was coated using a gravure coater, dried at 100 ° C., and then irradiated with ultraviolet rays to cure the coating layer, and the medium refractive index layer (refractive index: 1. 63, film thickness: 67
nm). The above-mentioned coating liquid for high refractive index layer is applied onto the medium refractive index layer using a gravure coater, and the temperature is 100 ° C.
After being dried at 1, the coating layer was cured by irradiating with ultraviolet rays to form a high refractive index layer (refractive index: 1.90, film thickness: 107 nm). Further, the above low-refractive-index layer coating liquid was applied onto the high-refractive-index layer using a gravure coater, and the coating was performed at 120 ° C.
The coating layer is cured for a minute, and the low refractive index layer (refractive index: 1.4
3, film thickness: 86 nm). In this way, an antireflection film was prepared.

(Evaluation of Antireflection Film) The obtained film was evaluated for the following items. The results are summarized in Table 1. (1) The specular reflectance and tint spectrophotometer V-550 (manufactured by JASCO Corporation) was equipped with an adapter ARV-474, and an emission angle of -5 at an incident angle of 5 ° in a wavelength range of 380 to 780 nm. The specular reflectance was measured, the average reflectance from 450 to 650 nm was calculated, and the antireflection property was evaluated. Further, from the measured reflection spectrum, CIE1976L * a showing the tint of specular reflection light with respect to the 5 degree incident light of the CIE standard light source D65.
The L * value, a * value, and b * value in the * b * color space were calculated, and the tint of the reflected light was evaluated. (2) Pencil hardness evaluation As an index of scratch resistance, the pencil hardness evaluation described in JIS K 5400 was performed. Anti-reflection film temperature 25 ℃, humidity 60
After conditioning the humidity for 2 hours at% RH, using a test pencil of 2H to 5H defined in JIS S 6006, the load is 500 g, the evaluation is as follows, and the highest hardness that is OK is evaluated. Value. No scratches to one scratch in the evaluation of n = 5: OK Three or more scratches in the evaluation of n = 5: NG (3) Contact angle measurement The optical material was used at a temperature of 25 ° C. as an index of the surface stain resistance.
After humidity was adjusted for 2 hours at a humidity of 60% RH, the contact angle of pure water was measured and used as an index of fingerprint adhesion. (4) Dynamic friction coefficient measurement The dynamic friction coefficient was evaluated as an index of surface slipperiness. The coefficient of kinetic friction was adjusted to 5 mmφ with a HEIDON-14 kinetic friction meter after conditioning the sample for 2 hours at 25 ° C and 60% relative humidity.
Stainless steel ball, load 100g, speed 60cm / min
The value measured in 1. was used. (5) Measurement of Vertical Peeling Charge The vertical peeling charge was measured by the method described in the text. (6) Surface resistance value The surface resistance value was measured by the circular electrode method.

Comparative Example Titanium oxide (refractive index: 2.3) was sequentially deposited on the hard coat of Example 1 by physical vapor deposition.
9) 25 nm and silicon oxide (refractive index 1.47) 25 nm
Substantially medium refractive index layer consisting of two layers, titanium oxide 46 nm
A high-refractive-index layer made of, and a low-refractive-index layer made of silicon oxide of 97 nm were formed to prepare an antireflection film.
The same evaluation as was done. FIG. 2 shows wavelengths of 380 nm to 78 of the antireflection films of Example 1 and Comparative Example 1 of the present invention.
The reflectance spectrum up to 0 nm is shown.

[Example 2] The antireflection film prepared in Example 1 was dipped in a 2.0 N NaOH aqueous solution at 55 ° C for 2 minutes to saponify the triacetyl cellulose surface on the back surface of the film to 80 µm. Of triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Photo Film Co., Ltd.) with different thickness is adsorbed with iodine on polyvinyl alcohol with a film saponified under the same conditions, and both sides of the polarizer prepared by stretching are bonded. , And protected and a polarizing plate was prepared. The polarizing plate prepared in this manner was used in a liquid crystal display device of a notebook computer equipped with a transmissive TN liquid crystal display device so that the antireflection film side became the outermost surface (Sumitomo 3M Co., Ltd., a polarization separation film having a polarization selection layer). When the manufactured D-BEF was attached to the polarizing plate on the viewing side (having the D-BEF between the backlight and the liquid crystal cell), a display device having a very low background reflection and a very high display quality was obtained.

[Example 3] The saponification treatment of Example 2 was repeated as follows.
A liquid crystal was prepared in the same manner as in Example 2 except that a 0 N aqueous KOH solution was applied to the back surface of the antireflection film with a # 3 bar, treated at a film surface temperature of 60 ° C. for 10 seconds, washed with water, and dried. When it was attached to a display device, a display device with high display quality similar to that of Example 2 was obtained.

[Embodiment 4] A protective film on the liquid crystal cell side of the polarizing plate on the visible side of the transmissive TN liquid crystal cell to which the antireflection film of Example 3 is attached and a liquid crystal cell side protection of the polarizing plate on the backlight side. In the film, the disc surface of the discotic structural unit is inclined with respect to the transparent support surface, and the angle formed by the disc surface of the discotic structural unit and the transparent support surface changes in the depth direction of the optical anisotropic layer. Viewing angle expansion film having an optical compensation layer (Wide View Film SA-12B, Fuji Photo Film Co., Ltd.)
Manufactured), a liquid crystal display device having a high contrast in a bright room, a wide viewing angle in the vertical and horizontal directions, a very high visibility, and a high display quality was obtained.

[Example 5] An antireflection film having a forward scattering function was prepared in the same manner as in Example 1 except that the coating liquid B for hard coat layer was used in place of the coating liquid A for hard coat. In the same manner as in Example 4, this forward scattering antireflection film was formed on the outermost surface side, and the viewing angle widening film wide view film (WV-12) was formed on the liquid crystal cell side.
A, a transmission type TN liquid crystal display device in which a polarizing plate having Fuji Photo Film Co., Ltd. was arranged was prepared. In the liquid crystal display device thus manufactured, the limit angle at which gradation inversion occurs when the viewing angle is tilted downward is improved from 40 degrees to 60 degrees as compared with Example 4, and the visibility and display quality are improved. It was very good at.

Example 6 The polarizing plate having the antireflection layer of Example 3 was placed on the outermost surface, and the antireflection film prepared in Example 1 was placed on both inner and outer sides of the acrylic front plate with an adhesive. When pasted together to create a mobile phone equipped with a semi-transmissive liquid crystal display device with the front plate on the outermost surface,
It was possible to obtain a display device having a high visibility comparable to that of a liquid crystal display device having an antireflection treatment without a front plate. In addition, as a result of simultaneously preparing the one in which the antireflection film of Example 1 was bonded only on the inside of the front plate, the one in which nothing was bonded, and the one without antireflection on both the front plate and the liquid crystal cell,
As the number of anti-reflection films decreased, the visibility deteriorated, and in the case without anti-reflection, the characters in the area where a fluorescent lamp was reflected became completely unreadable.

[Example 7] When the antireflection film prepared in Example 1 was attached to a glass plate on the surface of an organic EL display device via an adhesive, reflection on the glass surface was suppressed and visibility was improved. A high display device can be obtained.

[Embodiment 8] A glass plate on the surface of an organic EL display device was prepared by laminating a λ / 4 plate on the opposite surface of the polarizing plate with a single-sided antireflection film prepared in Example 3 on the side having an antireflection film. When it was attached to a plate, surface reflection and reflection from the inside of the surface glass were cut, and a display with extremely high visibility was obtained.

[Example 9] A single-sided undercoat layer having a thickness of 1
88 μm polyethylene terephthalate film (Cosmo Shine A4100, manufactured by Teijin Ltd., refractive index: 1.6
5) Coating solution C for hard coat was applied to the undercoat surface in the same manner as in Example 1, followed by drying the solvent and UV curing to form a hard coat layer (refractive index: 1.61, film thickness: 8 μm). . Subsequently, the coating liquid B for medium refractive index layer described above is coated using a gravure coater, dried at 100 ° C., and then irradiated with ultraviolet rays to cure the coating layer, and the medium refractive index layer (refractive index:
1.70, film thickness: 70 nm). The above-mentioned coating liquid for high refractive index layer was applied onto the medium refractive index layer using a gravure coater, dried at 100 ° C., and then irradiated with ultraviolet rays to cure the coating layer, and the high refractive index layer (refractive index Ratio: 1.90, film thickness: 120 nm). On top of the high refractive index layer,
The above low-refractive-index layer coating liquid was applied using a gravure coater, and the applied layer was cured at 120 ° C. for 8 minutes to provide a low-refractive index layer (refractive index: 1.43, film thickness: 90 nm). . In this way, an antireflection film was prepared and evaluated in the same manner as in Example 1. The tint of reflected light is remarkably reduced, and the pencil height is very high. When it is attached to the outermost surface of flat CRT and PDP, low reflection, reduced tint of reflected light and high film hardness are satisfied at the same time. The obtained display device was obtained.

[0057]

[Table 1]

The antireflection films of Examples 1 and 9 were
Both low reflectance and reduction of tint are compatible with each other, which is a very preferable reflection characteristic.
Not only is it resistant to damage, it also has low dynamic friction, so it has excellent scratch resistance.
The contact angle of pure water is high, so it has excellent water and oil repellency.
Therefore, it has excellent stain resistance, pencil hardness, and scratches.
It's hard to get along. Furthermore, 10 cm away in the TD and MD directions
Wavelengths from 380 nm to 780 at any two locations
5 degree incident light of CIE standard light source D65 in the nm range
The unevenness of the specular reflection light to CIE1976L * a
Within the range of 0 to 1.5 in the ΔEab * value of * b * color space
Therefore, the color uniformity of the reflected light at different locations is high.
Yes. In addition, the surface resistance value is 1 × 10 ¹²Ω / □ or more
However, the vertical peeling charge was +120 pc (picocool
) / Cm²And was excellent in dust resistance. Anti-comparative example
Reflection light is strongly colored in reddish purple on the anti-fire film.
The display quality was inferior. Also, because of high dynamic friction,
Inferior in scratch resistance, low contact angle of pure water, and poor antifouling property
Met.

Example 10 A polarizing plate was produced in the same manner as in Example 2 except that the polarizer produced by the following method was used as the polarizer of Example 2. The antireflection performance is shown in Example 1.
However, the absorption axis direction of the obtained polarizer was inclined by 45 ° with respect to the longitudinal direction, and the punching scraps generated when punching the polarizing plate into each size were reduced. (Production of Polarizer) PVA film with iodine 5.0 g /
1, potassium iodide 10.0 g / l in an aqueous solution at 25 ° C. for 90 seconds, and then boric acid 10 g / l in an aqueous solution.
After dipping at 5 ° C for 60 seconds, US Patent Publication No. 2002-88
Introduced to the tenter stretching machine of the form of Fig. 2 of No. 40A1,
The film was once stretched to 7.0 times and then shrunk to 5.3 times. Thereafter, the width was kept constant, dried at 70 ° C., and then removed from the tenter. The difference in transport speed between the left and right tenter clips is 0.0
It was less than 5%, and the angle formed by the center line of the film introduced and the center line of the film sent to the next step was 0 °. Here, both | L1-L2 | and W in Fig. 2 were 0.7 m. Wrinkles and film deformation at the tenter exit were not observed. The transmittance of this polarizer at 550 nm was 43.3%, and the polarization degree was 99.98%.

[0060]

The antireflection film of the present invention is 450 n
Since the average reflectance from m to 650 nm is 0.5% or less, when applied to a liquid crystal display, deterioration of visibility due to reflection of reflected light is prevented at a high level.
Further, when evaluated by the tint of the specular reflection light with respect to the 5 degree incident light of the CIE standard light source D65 in the wavelength range of 380 nm to 780 nm, the a * and b * values of the CIE1976L * a * b * color space are −7 ≦, respectively. a * ≦ 7, −10
Since it is within the range of ≦ b * ≦ 10, even when a high-luminance light source such as a fluorescent lamp on the back of the user who faces the display is reflected on the display surface, it is not colored red purple or blue purple, The display quality is not significantly deteriorated, at the same time, the unevenness of the tint with respect to the unevenness of the film thickness is small and the manufacturing yield is high. Further, since the vertical peeling charge amount is small, the dust resistance is excellent even if the surface resistance value is high. Further, a polarizing plate used in liquid crystal display devices of various modes, a surface protection plate in which a polarizing plate used in an organic EL and a λ / 4 plate are combined, and a plane CR applied to a PET film
It can be used for various displays such as a T or PDP surface protection plate.

[Brief description of drawings]

FIG. 1 is a schematic view showing a specific example of an antireflection film of the present invention.

FIG. 2 is reflectance spectra of the antireflection films of Example 1 and Comparative Example 1 of the present invention at wavelengths from 380 nm to 780 nm.

[Explanation of symbols]

1 transparent support 2 Hard coat layer 3 Middle refractive index layer 4 High refractive index layer 5 Low refractive index layer

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G02F 1/1335 G02F 1/1335 510 4F100 500 1/13363 5G435 510 1/139 1/13363 G09F 9/00 313 1/139 G02B 1/10 A G09F 9/00 313 ZF term (reference) 2H049 BA02 BA05 BA06 BA07 BA42 BB23 BB33 BC22 2H088 HA17 HA18 HA24 JA04 JA11 JA13 MA20 2H089 QA16 RA10 TA14 TA15 TA16 2H091 FA08X FA08Z FA11 FA14X FA08Z FA08 FA FA41Z FC02 FD06 HA10 LA30 2K009 AA06 AA15 BB24 BB28 CC03 CC24 CC26 DD02 DD05 4F100 AA21C AA25C AA27C AA28C AA29C AJ06A AK01B AK42A AR00D AR00E BA02 BA03 BA04 BA05 BA07 BA10A BA10B BA26 CA30C DE01C EH46 EH46C EJ42 EJ53 EJ53C EJ86C GB41 JB05B JB14A JB14B JK16B JN01A JN06 JN18A JN18B JN18C JN18D JN18E YY00A YY00B YY00C 5G435 AA02 BB05 BB06 BB12 FF04 FF05 FF14 HH02

Claims (24)

[Claims] 1. An antireflection film comprising a transparent support and at least one low refractive index layer having a refractive index lower than that of the support, and having a specular reflectance of 450 nm at 5 degrees incidence.
To 650 nm, the average value in the wavelength range from 0.5 to 650 nm is 0.5% or less, and the tint of specular reflection light with respect to the 5 degree incident light of the CIE standard light source D65 in the wavelength range from 380 nm to 780 nm is CIE1976L * a * b *. A * of color space,
b * values are −7 ≦ a * ≦ 7 and −10 ≦ b *, respectively.
An antireflection film having a range of ≦ 10. 2. In the antireflection film, a *,
b * values are 0 ≦ a * ≦ 5 and −7 ≦ b * ≦ 0, respectively.
The antireflection film according to claim 1, wherein the antireflection film is in the range of. 3. The antireflection film according to claim 1, wherein an average value of specular reflectance at 5 degrees incidence in a wavelength region from 450 nm to 650 nm is 0.4% or less. Anti-reflection film. 4. The antireflection film according to claim 1, wherein an average value of specular reflectance at 5 degrees incidence in a wavelength region from 450 nm to 650 nm is 0.3% or less. Anti-reflection film. 5. Each layer of the antireflection film is formed by applying a coating composition containing a film-forming solute and at least one solvent, drying the solvent, and curing with heat and / or ionizing radiation. The antireflection film according to any one of claims 1 to 4, which is a film. 6. A high refractive index layer having a refractive index higher than that of the support in order from the low refractive index layer side between the low refractive index layer and the transparent support, and the support and the high refractive index layer. The antireflection film according to claim 5, wherein substantially three layers, that is, a medium refractive index layer having an intermediate refractive index, having different refractive indexes are formed. 7. In the antireflection film, the medium refractive index layer has the following formula (I) for a design wavelength λ (= 500 nm).
The high-refractive-index layer satisfies the following formula (II), and the low-refractive-index layer satisfies the following formula (III). lλ / 4 × 0.80 <n1d1 <lλ / 4 × 1.00 (I) mλ / 4 × 0.75 <n2d2 <mλ / 4 × 0.95 (II) nλ / 4 × 0.95 <n3d3 < nλ / 4 × 1.05 (III) (wherein, 1 is 1, n1 is the refractive index of the medium refractive index layer, and d1 is the layer thickness (nm) of the medium refractive index layer. , M is 2, n2 is the refractive index of the high refractive index layer, and d2 is the layer thickness (nm) of the high refractive index layer,
(n is 1, n3 is the refractive index of the low refractive index layer, and d3 is the layer thickness (nm) of the low refractive index layer) 8. A transparent support having a refractive index of 1.45 to 1.55, wherein n1 is 1.60 to 1.65, n2 is 1.85 to 1.95, and n3 is 1.35. The antireflection film according to claim 7, which has a refractive index of 1.45. 9. A transparent support having a refractive index of 1.55 to 1.65, n1 of 1.65 to 1.75, n2 of 1.85 to 2.05 and n3 of 1.35. The antireflection film according to claim 7, which has a refractive index of 1.45. 10. The antireflection film according to claim 5, wherein the low refractive index layer of the antireflection film is made of a heat- or ionizing radiation-curable fluorine-containing curable resin. . 11. The high refractive index layer of the antireflection film, ultrafine particles containing at least one metal oxide selected from oxides of Ti, Zr, In, Zn, Sn, Sb, anionic dispersion Agent, a coating composition containing a curable resin having a tri- or more functional polymerizable group and a polymerization initiator is applied, the solvent is dried, and the composition is formed by curing with heat and / or ionizing radiation. The antireflection film according to claim 5. 12. The low refractive index layer of the antireflection film has a dynamic friction coefficient of 0.15 or less and a pure water contact angle of 100.
11. The antireflection film according to claim 10, wherein the antireflection film is at least one degree. 13. The antireflection film according to claim 1, further comprising at least one hard coat layer between the low refractive index layer and the transparent support. 14. The antireflection film according to claim 1, which has at least one forward scattering layer between the low refractive index layer and the transparent support. 15. TD or MD direction 10 cm
Wavelengths from 380 nm to 7 in any two separate locations
The tint unevenness of the specular reflection light with respect to the 5 degree incident light of the CIE standard light source D65 in the 80 nm region is CIE1976L.
The ΔEab * value in the * a * b * color space is less than 2, and the antireflection film according to any one of claims 1 to 14. 16. The vertical peeling charge of either triacetyl cellulose or polyethylene terephthalate measured at room temperature and normal humidity is -200 pc (pico coulomb) / cm ² to +200 pc (pico coulomb) / cm ² and has a surface resistance. A value of 1 × 10 ¹¹ Ω / □ or more, characterized in that
The antireflection film according to any one of items. 17. A polarizing plate in which two surface protective films are attached to the front and back surfaces of a polarizer, and
After forming the low refractive index layer of the antireflection film according to any one of the above, by dipping at least once in an alkaline solution, the antireflection film saponified on the back surface of the film to at least one surface protective film A polarizing plate characterized by being used. 18. A polarizing plate in which two surface protective films are attached to the front surface and the back surface of a polarizer, and
Before or after forming the surface forming the low refractive index layer of the antireflection film according to any one of the items, an alkaline solution is applied to the surface opposite to the surface forming the low refractive index layer of the antireflection film, A polarizing plate, characterized in that an antireflection film obtained by saponifying only the back surface of the film by heating, washing with water and / or neutralization is used for at least one surface protection film. 19. An optical compensation film, wherein the film other than the antireflection film of the surface protection film has an optical compensation layer containing an optically anisotropic layer on the surface of the surface protection film opposite to the polarizer. The optical anisotropic layer is a layer having a negative birefringence composed of a compound having a discotic structural unit, the disc surface of the discotic structural unit is inclined with respect to the surface protective film surface, and 19. The angle formed by the disc surface of the discotic structural unit and the surface of the surface protective film changes in the depth direction of the optically anisotropic layer.
The polarizing plate described in. 20. A TN, STN, VA having at least one polarizing plate according to claim 17.
A transmissive type, a reflective type, or a semi-transmissive type liquid crystal display device of IPS and OCB modes. 21. A transmissive or semi-transmissive liquid crystal display device comprising at least one polarizing plate according to claim 17, wherein the polarizing plate and the backlight are on the side opposite to the viewing side. A liquid crystal display device, characterized in that a polarization separation film having a polarization selection layer is arranged between the two. 22. The transparent support is a triacetyl cellulose film, a polyethylene terephthalate film,
Or it is a polyethylene naphthalate film, The antireflection film of any one of Claims 1-16 characterized by the above-mentioned. 23. The transparent protective film on the side opposite to the antireflection film of the polarizing plate according to claim 17 or 18,
A transmissive or semi-transmissive liquid crystal device having a λ / 4 plate. 24. The transparent protective film on the side opposite to the antireflection film of the polarizing plate according to claim 17 or 18,
An organic EL display device having a λ / 4 plate arranged.