JP4914564B2 - Antireflection film, polarizing plate and liquid crystal display device - Google Patents

Description

  The present invention relates to an antireflection film, a polarizing plate using the same, and a liquid crystal display device.

  In general, an antireflection film prevents contrast reduction and image reflection due to reflection of external light in an image display device such as a cathode ray tube display (CRT), a plasma display (PDP), and a liquid crystal display (LCD). In order to reduce the reflectivity using the principle of optical interference, it is placed on the outermost surface of the display.

  In order to reduce the reflectance in the antireflection film, the low refractive index layer must have a sufficiently low refractive index. Examples of materials that lower the refractive index include magnesium fluoride and calcium fluoride for inorganic materials, and fluorine-containing compounds with a high fluorine content for organic materials. Was lacking in scratch resistance. Moreover, since it is indispensable to give antifouling property for the film arrange | positioned on the outermost surface, patent document 1 (Unexamined-Japanese-Patent No. 2002-265866) and Patent Document 2 (Unexamined-Japanese-Patent No. 2002-317152) However, it is difficult to obtain sufficient antifouling property only by the technique disclosed in Japanese Patent No. 315,900. Therefore, in order to satisfy both low reflection and sufficient scratch resistance and antifouling properties, a so-called low surface free energy compound having a low refractive index, excellent strength, and difficult to get dirty on the surface is necessary. In this case, there is a trade-off relationship that when one is improved, the other is worsened, and it has been difficult to satisfy both the reduction in reflectance and the scratch resistance and antifouling properties.

  As a viewpoint of reducing the reflectivity, Patent Document 3 (Japanese Patent Laid-Open No. 7-287102) describes that the reflectivity is reduced by increasing the refractive index of the hard coat layer. However, since such a high refractive index hard coat layer has a large difference in refractive index with the support, color unevenness of the film occurs, and the wavelength dependence of the reflectance also greatly fluctuates.

  Further, in Patent Document 4 (Japanese Patent Laid-Open No. 7-333404), an antiglare antireflection film having excellent gas barrier properties, antiglare properties, and antireflection properties is described, but a silicon oxide film by CVD is essential. Therefore, productivity is inferior compared with wet coating.

Since the antireflection film is applied in a very thin region of about ½ to ¼ of the visible light wavelength, the film thickness unevenness on the order of several nm results in a large film thickness deviation. Furthermore, since slight color unevenness of each layer is largely shifted by color unevenness and is visually detected as unevenness, a coating method for accurately controlling the film thickness is very important.
As the coating method of the antireflection film, dip coating, micro gravure, reverse roll coating, etc. have been mainly used so far. In the dip coating method, vibration of the coating liquid in the liquid receiving tank is inevitable, and stepped unevenness is likely to occur. In the reverse roll coating method and the micro gravure method, stepped unevenness is likely to occur due to roll eccentricity and deflection related to coating. Also, in the microgravure method, uneven coating amount tends to occur due to the manufacturing accuracy of the gravure roll and the change of the roll and the blade due to the contact between the blade and the gravure roll. Further, since these coating methods are post-measuring methods, it is relatively difficult to ensure a stable film thickness. Therefore, in these coating methods, it is difficult to increase the coating speed beyond a certain speed, and although the productivity is higher than that of the vapor deposition method or the like, the high productivity inherent in coating is not fully utilized.
Patent Document 5 (Japanese Patent Laid-Open No. 7-151904) proposes a method of applying an antireflection layer by a die coating method. Since the die coating method is a pre-measuring method, it has an advantage of high film thickness stability. However, when coating is performed using a generally used die configuration, it is possible to realize only high speed comparable to the above-described various coating methods. Specifically, in a thin layer coating such as an antireflection layer, film thickness unevenness that occurs in a direction perpendicular to and parallel to the transport direction of the transparent support significantly occurs, and it is difficult to maintain film thickness stability. In Patent Document 5, there is no particular limitation on the configuration of the die, a general die is assumed, and no particular proposal is made regarding the shape of the die. On the other hand, Patent Document 6 (Japanese Patent Application Laid-Open No. 2003-200097) shows that a thin layer can be applied with high accuracy by devising the structure of the die. By using this method, it is possible to apply a thin layer such as an antireflection layer with high accuracy. However, both the die coating method disclosed in Patent Document 5 and the die coating method disclosed in Patent Document 6 can be applied at high speed depending on the type of liquid. It was difficult to apply the coating on the surface, and sometimes it was impossible to apply the coating itself.
JP 2002-265866 A JP 2002-317152 A JP 7-287102 A JP 7-333404 A JP 7-151904 A JP 2003-200097 A

An object of the present invention is to provide an antireflection film that can be produced easily and inexpensively and that has sufficient antireflection performance and scratch resistance, as well as antifouling properties.
Another object of the present invention is to provide a method for producing an antireflection film having high film thickness uniformity, and to provide a polarizing plate and a liquid crystal display device using such an excellent antireflection film. is there.

According to the present invention, an antireflection film having the following constitution, a production method thereof, a polarizing plate and a liquid crystal display device are provided, and the above object is achieved.
[1]
A polymer binder having a saturated hydrocarbon chain or polyether chain substantially free of fluorine as a main chain in a low refractive index layer located farthest from the transparent support, hollow silica particles, and a compound for reducing surface free energy; The hollow silica particles have a porosity x of 10 to 60% represented by the formula (I) when the radius of the cavity in the particle is a and the radius of the outer shell of the particle is b, The compound for reducing the surface free energy is a silicone compound having a (meth) acryloyl group at the end and / or side chain of a compound chain containing a plurality of dimethylsilyloxy units as repeating units, and reduces the surface free energy. An antireflection film comprising a compound in a range of 0.01 to 20% by mass of the total solid content of the low refractive index layer.
Formula (I): x = (4πa 3/3) / (4πb 3/3) × 100
[2]
The antireflection film as described in [1], wherein the hollow silica particles are treated with a silane coupling agent having an acryloyl group or a methacryloyl group.
[3]
Silicone emission is segregated on the surface of the low refractive index layer, it photoelectron spectral intensity ratio Si / C in 80% lower from the outermost surface and the outermost surface of the low refractive index layer is greater 80% 5 times more than the lower layer in the outermost surface The antireflection film as described in [1] or [2].
[ 4 ]
Surface reflection energy is 25 mN / m or less, The antireflection film in any one of [1]-[ 3 ] characterized by the above-mentioned.
[ 5 ]
The following general formula (A) is produced in the presence of an acid catalyst and / or a metal chelate compound in at least one of the low refractive index layer farthest from the transparent support and the lower layer of the low refractive index layer. The antireflection film according to any one of [1] to [ 4 ], comprising at least one of a hydrolyzate of an organosilane and a partial condensate thereof.
General formula (A): (R ¹⁰ ) _m Si (X) _4-m
(In the formula, R ¹⁰ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. X represents a hydroxyl group or a hydrolyzable group. M represents an integer of 1 to 3.)
[ 6 ]
In the method for producing an antireflection film according to any one of [1] to [ 5 ],
The land of the tip lip of the slot die is brought close to the surface of the transparent support that is continuously supported by the backup roll, and from the slot of the tip lip, a saturated hydrocarbon chain or polyether chain substantially free of fluorine. And a void having a porosity x represented by the formula (I) where the radius of the cavity in the particle is a and the radius of the outer shell of the particle is b Application of a coating solution containing silica particles and a compound that reduces the surface free energy, which is a silicone compound having a (meth) acryloyl group at the end and / or side chain of a compound chain containing a plurality of dimethylsilyloxy units as repeating units. The land length in the web traveling direction of the tip lip on the transparent support traveling direction side of the slot die is 30 μm or less. When a slot die having a size of 100 μm or less is used and the slot die is set at a coating position, a gap between the tip lip and the web on the opposite side to the moving direction of the web is set to the tip lip and the web on the web moving direction side. At least one low refractive index layer located farthest from the transparent support, with a dry film thickness of 200 nm or less, using a coating apparatus installed to be 30 μm or more and 120 μm or less larger than the gap between A method for producing an antireflection film.
[ 7 ]
The viscosity at the time of application | coating of this coating liquid is 2.0 [mPa * sec] or less, and the quantity of the coating liquid apply | coated to a transparent support body is 2.0-5.0 [ml / m < ² >], It is characterized by the above-mentioned. [The manufacturing method of the antireflection film as described in 6 .
[ 8 ]
A polarizing plate provided with the antireflection film according to any one of [1] to [ 5 ] or the antireflection film obtained by the method for producing an antireflection film according to [ 6 ] or [ 7 ].
[ 9 ]
The antireflection film according to any one of [1] to [ 5 ], the antireflection film obtained by the method for producing an antireflection film according to [ 6 ] or [ 7 ], or the polarizing plate according to [ 8 ] A liquid crystal display device provided.
In addition, although this invention is related to said [1]-[ 9 ], the following other matter was also described for reference.
1. An antireflection film comprising a low-refractive-index layer located farthest from a transparent support and containing hollow silica particles and a compound that reduces surface free energy.
2. 2. The antireflection film as described in 1 above, wherein the compound for reducing the surface free energy is at least one selected from a silicone compound and a fluorine-based compound.
3. Item 3. The antireflection film according to Item 2, wherein the compound that reduces the surface free energy is a silicone compound.
4). 4. The antireflection film as described in any one of 1 to 3 above, wherein the compound for reducing the surface free energy contains at least one group having reactivity with the binder in the molecule.
5. 5. The antireflection film as described in any one of 1 to 4 above, wherein the compound for reducing the surface free energy contains at least one (meth) acryloyl group in the molecule.
6). An antireflection film comprising: a hollow silica particle and a binder having a surface free energy lowering ability in a low refractive index layer located farthest from a transparent support.
7). Silicone and / or fluoroalkyl groups segregate on the surface of the low refractive index layer, and the photoelectron spectrum intensity ratio Si / C and / or F / C in the lower layer of the low refractive index layer and 80% below the outermost surface is the outermost surface. The antireflection film as described in any one of 1 to 6 above, which is at least 5 times larger than the 80% lower layer.
8). In the above 6 or 7, wherein the low refractive index layer located farthest from the transparent support contains hollow silica particles and a binder having a surface free energy reducing ability, and the binder contains silicone and / or fluorine. The antireflection film as described.
9. The antireflection film as described in any one of 6 to 8 above, wherein the binder having a surface energy reducing ability is a fluoropolymer.
10. 10. The antireflection film as described in any one of 6 to 9 above, wherein the binder having a surface free energy reducing ability is a compound having at least one (meth) acryloyl group.
11. 11. The antireflection film as described in any one of 6 to 10 above, wherein the binder is represented by the general formula 1.

12 12. The antireflection film as described in any one of 1 to 11 above, wherein the surface free energy is 25 mN / m or less.
13. The following general formula (A) is produced in the presence of an acid catalyst and / or a metal chelate compound in at least one of the low refractive index layer farthest from the transparent support and the lower layer of the low refractive index layer. The antireflective film of Claims 1-12 containing at least any one of the hydrolyzate of the organosilane represented, and its partial condensate.
General formula (A): (R ¹⁰ ) _m Si (X) _4-m
(In the formula, R ¹⁰ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. X represents a hydroxyl group or a hydrolyzable group. M represents an integer of 1 to 3.)
14. In the method for producing an antireflection film according to 14.1 to 13, the land of the tip lip of the slot die is brought close to the surface of the transparent support that is supported by the backup roll and continuously runs, from the slot of the tip lip. In the method of applying a coating solution, a slot die having a land length in the web running direction of the tip lip on the transparent die traveling direction side of the slot die is used, and the slot die is set at a coating position. A coating device installed so that a gap between the tip lip on the opposite side to the web traveling direction and the web is larger than the gap between the tip lip on the web traveling direction side and the web by 30 μm or more and 120 μm or less. An antireflection film characterized by applying at least one layer having a dry film thickness of 200 nm or less. Method of manufacturing a Irumu.
15. The viscosity at the time of application | coating of this coating liquid is 2.0 [mPa * sec] or less, and the quantity of the coating liquid apply | coated to a transparent support body is 2.0-5.0 [ml / m < ² >], It is characterized by the above-mentioned. 15. The method for producing an antireflection film as described in 14 above.
16. A polarizing plate comprising the antireflection film according to any one of 1 to 13 or the antireflection film obtained by the method for producing an antireflection film according to 14 or 15.
17. 16. A liquid crystal display device comprising the antireflection film according to any one of 1 to 13, the antireflection film obtained by the method for producing an antireflection film according to 14 or 15, or the polarizing plate according to 16.

The antireflection film of the present invention can be produced easily and inexpensively, and has sufficient antireflection performance, scratch resistance and antifouling properties. Moreover, according to this invention, the manufacturing method of an antireflection film with high film thickness uniformity is provided.
Furthermore, a polarizing plate provided with the above antireflection film of the present invention is provided, and the liquid crystal display device of the present invention comprising these antireflection film and polarizing plate is visually recognized because the antireflection film is disposed on the outermost surface Excellent scratch resistance and antifouling properties.

A basic configuration of an antireflection film suitable as an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view schematically showing an example of the antireflection film of the present invention. In this case, the antireflection film 1 has a layer structure in the order of a transparent support 2, a conductive layer 3, a hard coat layer 4, a medium refractive index layer 5, a high refractive index layer 6, and a low refractive index layer 7. The middle refractive index layer 5 and the high refractive index layer 6 may or may not be present, and the hard coat layer 4 may or may not include the mat particles 8. The refractive index of the hard coat layer 4 is preferably in the range of 1.50 to 2.00, and the refractive index of the low refractive index layer 7 is preferably in the range of 1.38 to 1.49. When the high refractive index layer 6 and the medium refractive index layer 5 are used, the refractive index may be in the order of the low refractive index layer 7 <the medium refractive index layer 5 <the high refractive index layer 6. Although the conductive layer 3 is not essential, it is preferably coated, and may be present in any of the configurations of the antireflection film, not between the transparent support 2 and the hard coat layer 4. May be integrated with any of the above layers. In the present specification, when a numerical value represents a physical property value, a characteristic value, etc., the description “(numerical value 1) to (numerical value 2)” means “(numerical value 1) or more and (numerical value 2) or less”. .

[Low refractive index layer]
First, the low refractive index layer of the present invention will be described.
The refractive index of the low refractive index layer of the antireflection film of the present invention is in the range of 1.38 to 1.49, preferably 1.38 to 1.44. Further, the low refractive index layer preferably satisfies the following formula (I) from the viewpoint of reducing the reflectance.
(Mλ / 4) × 0.7 <n ₁ d ₁ <(mλ / 4) × 1.3 (Equation (I))
In the formula, m is a positive odd number, n ₁ is the refractive index of the low refractive index layer, and d ₁ is the film thickness (nm) of the low refractive index layer. Further, λ is a wavelength, which is a value in the range of 500 to 550 nm. In addition, satisfy | filling said numerical formula (I) means that m (positive odd number, usually 1) which satisfy | fills numerical formula (I) exists in the said wavelength range.

The present invention is characterized in that the low refractive index layer contains hollow silica particles and a compound that reduces surface free energy.
The hollow silica particles contained in the low refractive index layer of the present invention will be described below.
The hollow silica particles preferably have a refractive index of 1.17 to 1.40, more preferably 1.17 to 1.35, and most preferably 1.17 to 1.30. The refractive index here represents the refractive index of the entire particle, and does not represent the refractive index of only the outer shell silica forming the hollow silica particles. At this time, when the radius of the void in the particle is a and the radius of the particle outer shell is b, the porosity x represented by the following formula (I) is preferably 10 to 60%, more preferably 20 to 60. %, Most preferably 30-60%.
Formula (I): x = (4πa 3/3) / (4πb 3/3) × 100
If the hollow silica particles are made to have a lower refractive index and a higher porosity, the thickness of the outer shell becomes thinner and the strength of the particles becomes weaker. From the viewpoint of scratch resistance, the low refractive index is less than 1.17. Rate particles do not hold. The refractive index of these hollow silica particles was measured with an Abbe refractometer (manufactured by Atago Co., Ltd.). A method for producing hollow silica is described in, for example, Japanese Patent Application Laid-Open Nos. 2001-233611 and 2002-79616.

The coating amount of the hollow silica is, in view of the effect and scratch resistance improvement effect of reducing the refractive index, in terms of outer appearance or integrated reflectance, such as tightness of ^{black, 1mg / m 2 ~100mg / m} 2 are preferred, more preferably ^{5mg / m 2 ~80mg / m 2} , more preferably from ^{10mg / m 2 ~60mg / m 2} . The average particle diameter of the hollow silica is preferably 30% to 150% of the thickness of the low refractive index layer, more preferably 35% to 80%, and still more preferably 40% to 60%. That is, if the thickness of the low refractive index layer is 100 nm, the particle size of the hollow silica is preferably 30 nm to 150 nm, more preferably 35 nm to 80 nm, and still more preferably 40 nm to 60 nm.
When the particle size of the silica fine particles is in the above range, the ratio of the cavity portion is appropriate, the refractive index is lowered, and fine irregularities generated on the surface of the low refractive index layer are suppressed, and the appearance is deteriorated such as black tightening. The integrated reflectance is not deteriorated.
The silica fine particles may be either crystalline or amorphous, and monodisperse particles are preferred. The shape is most preferably a spherical diameter, but there is no problem even if the shape is indefinite. Here, the average particle diameter of the hollow silica can be determined from an electron micrograph.

  In the present invention, silica particles having no voids can be used in combination with hollow silica. The preferred particle size of silica without voids is 30 nm to 150 nm, more preferably 35 nm to 80 nm, and most preferably 40 nm to 60 nm. In addition, at least one kind of silica fine particles having an average particle size of less than 25% of the thickness of the low refractive index layer (referred to as “silica fine particles with small size particle size”) is used as silica fine particles with the above particle size (“large size particles”). It is preferably used in combination with “silica fine particles having a diameter”. Since the fine silica particles having a small size can be present in the gaps between the fine silica particles having a large size, the fine particles can contribute as a retaining agent for the fine silica particles having a large size. The average particle diameter of the silica fine particles having a small size is preferably 1 nm to 20 nm, more preferably 5 nm to 15 nm, and particularly preferably 10 nm to 15 nm. Use of such silica fine particles is preferable in terms of raw material costs and a retaining agent effect.

In order to stabilize dispersion in the dispersion liquid or coating liquid, or to increase the affinity and binding properties with the binder component, the silica fine particles are used in a physical surface such as plasma discharge treatment or corona discharge treatment. Chemical surface treatment with a treatment, a surfactant, a coupling agent, or the like may be performed. The use of a coupling agent is particularly preferred. As the coupling agent, an alkoxy metal compound (eg, titanium coupling agent, silane coupling agent) is preferably used. Among these, treatment with a silane coupling agent having an acryloyl group or a methacryloyl group is particularly effective. The above-mentioned coupling agent is used as a surface treatment agent for the inorganic filler of the low refractive index layer in advance for surface treatment prior to the preparation of the layer coating solution. It is preferable to make it contain in a layer. The silica fine particles are preferably dispersed in the medium in advance before the surface treatment in order to reduce the load of the surface treatment.
Further, the low refractive index layer may contain fine particles other than silica fine particles such as magnesium fluoride fine particles in combination with hollow silica as long as the achievement of the object of the present invention is not impaired.

The surface free energy (γs ^v : unit, mN / m) of the antireflection film of the present invention was experimentally measured on the antireflection film with reference to DKOwens: J.Appl.Polym.Sci., 13,1741 (1969). Table by the sum of pure water between H ₂ O and the respective contact angle theta _{H2 O} in methylene iodide CH ₂ I _2, where theta following simultaneous equations from _CH2I2 (1), γs ^d and gamma] s ^h was calculated from (2) obtained in It is defined by the surface tension of the antireflection film calculated by the calculated value γs ^v (= γs ^d + γs ^h ). The smaller this γs ^v and the lower the surface free energy, the higher the surface repellency and the better the antifouling property. The surface free energy of the antireflection film is preferably 25 mN / m or less, and particularly preferably 20 mN / m or less.
_{(1): 1 + cosθ H2O} = 2√γs d (√γ H2O d / γ H2O v) + 2√γs h (√γ H2O h / γ H2O v)
_{(2): 1 + cosθ CH2I2} = 2√γs d (√γ CH2I2 d / γ CH2I2 v) + 2√γs h (√γ CH2I2 h / γ CH2I2 v)
* Γ _H2O ^d = 21.8, γ _H2O ^h = 51.0, γ _H2O ^v = 72.8, γ _CH2I2 ^d = 49.5, γ _CH2I2 ^h = 1.3, γ _CH2I2 ^v = 50.8, The measurement of the contact angle is carried out under the same condition after conditioning the antireflection film for 1 hour or more at 25 ° C. and 60%.

  The compound for reducing the surface free energy and the binder having the ability to reduce the surface free energy used in the present invention are compounds that can significantly reduce the surface free energy of the antireflection film defined above by using each of the compounds. The structure and composition are not limited. In general, when the compound is used, the decrease in surface free energy does not become linear with respect to the amount used, and eventually saturates as the amount used increases. For example, the surface free energy at the addition amount of the compound at the point where the decrease in surface free energy obtained by plotting the decrease in surface free energy against the amount used in a cured matrix system formed with a binder such as DPHA is saturated. Is preferably 10 mN / m or more, more preferably 20 mN / m or more, particularly preferably 25 mN / m or more, and most preferably 30 mN / m or more.

  As the compound for reducing the surface free energy, a known silicone compound or fluorine-based compound can be used. In the case of adding these, it is preferably added in the range of 0.01 to 20% by mass of the total solid content of the low refractive index layer, more preferably in the range of 0.05 to 10% by mass. Yes, particularly preferably 0.1 to 5% by mass.

  Preferable examples of the silicone compound include those having a substituent at the terminal and / or side chain of a compound chain containing a plurality of dimethylsilyloxy units as repeating units. The compound chain containing dimethylsilyloxy as a repeating unit may contain a structural unit other than dimethylsilyloxy. The substituents may be the same or different, and a plurality of substituents are preferable. Examples of preferred substituents include acryloyl group, methacryloyl group, vinyl group, aryl group, cinnamoyl group, epoxy group, oxetanyl group, hydroxyl group, fluoroalkyl group, polyoxyalkylene group, carboxyl group, amino group and the like. It is done. Although there is no restriction | limiting in particular in molecular weight, It is preferable that it is 100,000 or less, It is more preferable that it is 50,000 or less, It is especially preferable that it is 3000-30000, It is most preferable that it is 10,000-20000. Although there is no restriction | limiting in particular in silicone atom content of a silicone type compound, it is preferable that it is 18.0 mass% or more, it is especially preferable that it is 25.0-37.8 mass%, and 30.0-37.0. Most preferably, it is mass%. Examples of preferable silicone compounds include X-22-174DX, X-22-2426, X-22-164B, X22-164C, X-22-170DX, X-22-176D, X, manufactured by Shin-Etsu Chemical Co., Ltd. -22-1821 (named above), Chisso Corporation, FM-0725, FM-7725, FM-4421, FM-5521, FM6621, FM-1121, Gelest DMS-U22, RMS-033, RMS- Examples include, but are not limited to, 083, UMS-182, DMS-H21, DMS-H31, HMS-301, FMS121, FMS123, FMS131, FMS141, and FMS221 (named above).

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

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

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

  The binder that can be used for the low refractive index layer of the antireflection film of the present invention will be described. The binder is preferably a polymer having a saturated hydrocarbon chain or a polyether chain as a main chain, and more preferably a polymer having a saturated hydrocarbon chain as a main chain. The binder polymer preferably has a crosslinked structure.

  As the binder polymer having a saturated hydrocarbon chain as a main chain, a polymer of an ethylenically unsaturated monomer is preferable. As the binder polymer having a saturated hydrocarbon chain as the main chain and having a crosslinked structure, a (co) polymer of monomers having two or more ethylenically unsaturated groups is preferable.

  Examples of the monomer having two or more ethylenically unsaturated groups include esters of polyhydric alcohol and (meth) acrylic acid (eg, ethylene glycol di (meth) acrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetra ( (Meth) acrylate), pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, di Pentaerythritol hexa (meth) acrylate, 1,2,3-cyclohexanetetramethacrylate, polyurethane polyacrylate, polyester polyacrylate), vinylbenzene and its derivatives Examples are 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1,4-divinylcyclohexanone), vinyl sulfone (eg, divinyl sulfone), acrylamide (eg, methylenebisacrylamide) and methacrylamide. Can be mentioned. Two or more of these monomers may be used in combination. In the present specification, “(meth) acrylate” represents “acrylate or methacrylate”.

  Polymerization of these monomers having an ethylenically unsaturated group can be performed by irradiation with active energy rays or heating in the presence of a photo radical initiator or a thermal radical initiator. Accordingly, a coating liquid containing a monomer having an ethylenically unsaturated group, a photo radical initiator or a thermal radical initiator, mat particles and an inorganic filler is prepared, and the coating liquid is applied on a transparent support, and then an active energy ray. Or it can harden | cur by the polymerization reaction by a heat | fever and can form an antireflection film.

  As radical photopolymerization initiators, acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds And fluoroamine compounds and aromatic sulfoniums. Examples of acetophenones include 2,2-diethoxyacetophenone, p-dimethylacetophenone, 1-hydroxydimethylphenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-4-methylthio-2-morpholinopropiophenone and 2 -Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone is included. Examples of benzoins include benzoin benzene sulfonate, benzoin toluene sulfonate, benzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether. Examples of the benzophenones include benzophenone, 2,4-dichlorobenzophenone, 4,4-dichlorobenzophenone and p-chlorobenzophenone. Examples of phosphine oxides include 2,4,6-trimethylbenzoyldiphenylphosphine oxide. Various examples are described in the latest UV curing technology (P.159, issuer; Kazuhiro Takasagi, publisher; Technical Information Association, Inc., published in 1991), which is useful for the present invention. Preferable examples of commercially available photocleavable photoradical polymerization initiators include Irgacure (651, 184, 907) manufactured by Ciba Specialty Chemicals. It is preferable to use a photoinitiator in the range of 0.1-15 mass parts with respect to 100 mass parts of polyfunctional monomers, More preferably, it is the range of 1-10 mass parts. In addition to the photopolymerization initiator, a photosensitizer may be used. Specific examples of the photosensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, Michler's ketone and thioxanthone.

  As the thermal radical initiator, organic or inorganic peroxides, organic azo, diazo compounds, and the like can be used. Specifically, benzoyl peroxide, halogen benzoyl peroxide, lauroyl peroxide, acetyl peroxide, dibutyl peroxide, cumene hydroperoxide, butyl hydroperoxide as organic peroxides, hydrogen peroxide, peroxides as inorganic peroxides. Ammonium sulfate, potassium persulfate, etc., 2-azo-bis-isobutyronitrile, 2-azo-bis-propionitrile, 2-azo-bis-cyclohexanedinitrile, etc. as diazo compounds, diazoaminobenzene, p -Nitrobenzenediazonium etc. can be mentioned.

  The polymer having a polyether as a main chain used as a binder for the low refractive index layer is preferably a ring-opening polymer of a polyfunctional epoxy compound. The ring-opening polymerization of the polyfunctional epoxy compound can be performed by irradiation with active energy rays or heating in the presence of a photoacid generator or a thermal acid generator. Therefore, a coating liquid containing a polyfunctional epoxy compound, a photoacid generator or a thermal acid generator, matte particles and an inorganic filler is prepared, and the coating liquid is applied onto a transparent support and then subjected to a polymerization reaction by active energy rays or heat. Can be cured to form an antireflection film.

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

  The binder having a surface free energy lowering ability used for the low refractive index layer of the antireflection film of the present invention is to add the binder to the surface free energy of the layer formed by curing with an alkyl acrylate monomer typified by DPHA. The binder is not particularly limited as long as the binder can lower the surface free energy. A binder having a surface free energy of 30 mN / m or less is particularly preferred, a binder having a surface density of 25 mN / m or less is more preferred, and a binder having a density of 20 mN / m or less is particularly preferred. The binder preferably contains at least one selected from a fluoroalkyl group, a dimethylsiloxane group, and a polydimethylsiloxane (so-called silicone) compound in the compound. The binder may be a monomer or a polymer before curing, and may be a mixture of a monomer and a polymer or a mixture of a plurality of compounds.

  Preferred examples of the binder having the ability to reduce the surface free energy used for the low refractive index layer will be described below. The binder having a surface free energy reducing ability preferably contains a fluorine-containing polymer as a low refractive index binder. The fluoropolymer is preferably a fluoropolymer that is crosslinked by heat or active energy rays having a dynamic friction coefficient of 0.03 to 0.15 and a contact angle with water of 90 to 120 °.

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

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

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

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

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

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

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

In general formula 1, L represents a linking group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, particularly preferably 2 to 4 carbon atoms, and may be a linear structure or a branched structure. It may have a ring structure and may have a heteroatom selected from O, N, and S. Preferred examples of L include *-(CH ₂ ) ₂ —O — **, * — (CH ₂ ) ₂ —NH — **, * — (CH ₂ ) ₄ —O — **, * — (CH _{2) 6 -O - **, *} - (CH 2) 2 -O- (CH 2) 2 -O - **, * - CONH- (CH 2) 3 -O - **, * - CH 2 CH (OH) CH ₂ —O — **, * —CH ₂ CH ₂ OCONH (CH ₂ ) ₃ —O — ** (* represents a connecting site on the polymer main chain side, and ** represents a (meth) acryloyl group side. And the like. m represents 0 or 1;

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

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

  Examples of preferred vinyl monomers include methyl vinyl ether, ethyl vinyl ether, t-butyl vinyl ether, cyclohexyl vinyl ether, isopropyl vinyl ether, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, glycidyl vinyl ether, vinyl ethers such as allyl vinyl ether, vinyl acetate, propionic acid Vinyl esters such as vinyl and vinyl butyrate, methyl (meth) acrylate, ethyl (meth) acrylate, hydroxyethyl (meth) acrylate, glycidyl methacrylate, allyl (meth) acrylate, (meth) acryloyloxypropyltrimethoxysilane, etc. (Meth) acrylates, styrene, styrene derivatives such as p-hydroxymethylstyrene, crotonic acid, male Acid, can be mentioned and unsaturated carboxylic acids and derivatives thereof such as itaconic acid, more preferably a vinyl ether derivative, vinyl ester derivatives, particularly preferably a vinyl ether derivative.

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

  The following general formula 2 is mentioned as a particularly preferred form of the copolymer used for the low refractive index layer of the antireflection film of the present invention.

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

  In the copolymer represented by the general formula 1 or 2, for example, a (meth) acryloyl group is introduced into a copolymer comprising a hexafluoropropylene component and a hydroxyalkyl vinyl ether component by any one of the methods described above. Can be synthesized.

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

  The copolymer used in the present invention is synthesized by synthesizing a precursor such as a hydroxyl group-containing polymer by various polymerization methods such as solution polymerization, precipitation polymerization, suspension polymerization, precipitation polymerization, bulk polymerization, and emulsion polymerization. It can be carried out by introducing a (meth) acryloyl group by the polymer reaction. The polymerization reaction can be performed by a known operation such as a batch system, a semi-continuous system, or a continuous system.

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

  Among the above polymerization methods, a solution polymerization method using a radical initiator is particularly preferable. Solvents used in the solution polymerization method include, for example, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, tetrahydrofuran, dioxane, N, N-dimethylformamide, N, N-dimethylacetamide, benzene, toluene, acetonitrile, A single organic solvent such as methylene chloride, chloroform, dichloroethane, methanol, ethanol, 1-propanol, 2-propanol, and 1-butanol, or a mixture of two or more thereof may be used, or a mixed solvent with water may be used.

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

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

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

Next, a method for measuring the segregation of silicone or fluoroalkyl groups on the surface of the low refractive index layer will be described. Each antireflection film was measured with ESCA-3400 (vacuum degree 1 × 10 ⁻⁵ Pa, X-ray source; target Mg, voltage 12 kV, current 20 mA) for each anti-reflection film, Si2p, F1s, C1s The photoelectron spectrum intensity ratio Si2p / C1s (= Si (a)), F1s / C1s (= F (a)) and the ion etching apparatus attached to ESCA-3400 (ion gun, voltage 2 kV, current 20 mA) has a low refractive index. The intensity ratio Si2p / C1s (= Si (b)), F1s / C1s (= F () of the photoelectron spectrum measured from the surface where the layer was shaved until the layer thickness became 1/5 (± 5%). b)), the change of the respective strength ratios before and after etching, Si (a) / Si (b), F (a) / F (b), are obtained, and the respective Si2p / C1s ratios are obtained. The degree of surface segregation is determined by the change in the 1s / C1s ratio before and after etching (the intensity ratio of the photoelectron spectrum at the top of the low refractive index layer / the intensity ratio of the photoelectron spectrum near the lower layer 80% deep from the surface of the low refractive index layer). it can. F1s and C1s determine the intensity at the peak position of each photoelectron spectrum, and Si2p uses the intensity at the peak position derived from the Si atom of silicone (polydimethylsiloxane) (bonding energy is around 105 eV) for the above intensity ratio calculation. It was distinguished from Si atoms derived from inorganic silica particles. Preliminary experiments are carried out in which the surface of the low refractive index layer is gradually scraped under various etching conditions in advance, and the depth from the surface is 80% based on the etching conditions required to reach the lower hard coat layer or high refractive index layer. Measure after obtaining the following conditions. When controlling only the surface properties, the surface segregation compounds described in this specification can be used appropriately to selectively place only the necessary components on the surface. It can be controlled independently.

The hydrolyzate / or partial condensate thereof of the organosilane compound used in the present invention, so-called sol component (hereinafter also referred to as such) will be described in detail below.
The organosilane compound is represented by the following general formula (A).
General formula (A): (R ¹⁰ ) _m Si (X) _4-m
In the general formula (A), R ¹⁰ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, hexyl, t-butyl, sec-butyl, hexyl, decyl, hexadecyl and the like. The alkyl group is preferably an alkyl group having 1 to 30 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 6 carbon atoms. Examples of the aryl group include phenyl and naphthyl, and a phenyl group is preferable.

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

There are no particular limitations on the substituents contained in R ^10, a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), a hydroxyl group, a mercapto group, a carboxyl group, an epoxy group, an alkyl group (methyl, ethyl, i- propyl , Propyl, t-butyl, etc.), aryl groups (phenyl, naphthyl, etc.), aromatic heterocyclic groups (furyl, pyrazolyl, pyridyl, etc.), alkoxy groups (methoxy, ethoxy, i-propoxy, hexyloxy, etc.), aryloxy (Phenoxy, etc.), alkylthio groups (methylthio, ethylthio, etc.), arylthio groups (phenylthio, etc.), alkenyl groups (vinyl, 1-propenyl, etc.), acyloxy groups (acetoxy, acryloyloxy, methacryloyloxy, etc.), alkoxycarbonyl groups (methoxy) Carbonyl, ethoxycarbonyl, etc.), A reeloxycarbonyl group (such as phenoxycarbonyl), a carbamoyl group (such as carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N-methyl-N-octylcarbamoyl), an acylamino group (acetylamino, benzoylamino, acrylicamino, Methacrylamino and the like, and these substituents may be further substituted. When there are a plurality of R ¹⁰ , at least one is preferably a substituted alkyl group or a substituted aryl group, and among them, an organosilane compound having a vinyl polymerizable substituent represented by the general formula (B) is preferable.

General formula (B)

In the general formula (B), R ¹ represents a hydrogen atom or a methyl group, a methoxy group, an alkoxycarbonyl group, a cyano group, a fluorine atom or a chlorine atom. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group. A hydrogen atom, methyl group, methoxy group, methoxycarbonyl group, cyano group, fluorine atom or chlorine atom is preferred, a hydrogen atom, methyl group, methoxycarbonyl group, fluorine atom or chlorine atom is more preferred, and a hydrogen atom or methyl group is particularly preferred preferable. Y represents a single bond or an ester group, an amide group, an ether group or a urea group. A single bond or an ester group or an amide group is preferred, a single bond or an ester group is more preferred, and an ester group is particularly preferred.

  L represents a divalent linking chain. Specifically, it has a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted alkylene group having a linking group (for example, ether, ester, amide) inside, and a linking group inside. Examples thereof include substituted or unsubstituted arylene groups, substituted or unsubstituted alkylene groups having 2 to 10 carbon atoms, substituted or unsubstituted arylene groups having 6 to 20 carbon atoms, and 3 to 10 carbon atoms having a linking group therein. An alkylene group, an unsubstituted alkylene group, an unsubstituted arylene group, an alkylene group having an ether or ester linking group therein is more preferred, an unsubstituted alkylene group, and an alkylene group having an ether or ester linking group inside Is particularly preferred. Examples of the substituent include a halogen, a hydroxyl group, a mercapto group, a carboxyl group, an epoxy group, an alkyl group, and an aryl group, and these substituents may be further substituted.

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

  Two or more compounds of the general formula (A) and general formula (B) may be used in combination. Specific examples of the compounds represented by formulas (A) and (B) are shown below, but the present invention is not limited to these.

  Among these specific examples, (M-1), (M-2), (M-5) and the like are particularly preferable.

(Vinegar catalyst, metal chelate compound)
The organosilane hydrolyzate and / or condensation reaction product (sol component) is preferably prepared in the presence of a catalyst. Catalysts include inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid; organic acids such as oxalic acid, acetic acid, formic acid, methanesulfonic acid and toluenesulfonic acid; inorganic bases such as sodium hydroxide, potassium hydroxide and ammonia; triethylamine, Examples include organic bases such as pyridine; metal alkoxides such as triisopropoxyaluminum and tetrabutoxyzirconium. From the viewpoint of production stability and storage stability of the inorganic oxide fine particle liquid, an acid catalyst is used in the present invention. (Inorganic acids, organic acids) and / or metal chelate compounds are used. Among inorganic acids, hydrochloric acid, sulfuric acid, and organic acids preferably have an acid dissociation constant in water (pKa value (25 ° C.)) of 4.5 or less, and an acid dissociation constant in hydrochloric acid, sulfuric acid, or water of 3.0 or less. More preferred is an organic acid, hydrochloric acid, sulfuric acid, an organic acid having an acid dissociation constant of 2.5 or less in water is more preferred, an organic acid having an acid dissociation constant in water of 2.5 or less is more preferred, and methanesulfonic acid Further, oxalic acid, phthalic acid, and malonic acid are more preferable, and oxalic acid is particularly preferable.

  When the hydrolyzable group of the organosilane is an alkoxy group and the acid catalyst is an organic acid, the amount of water added can be reduced because the carboxyl group or sulfo group of the organic acid supplies protons. The amount of water added relative to 1 mol of the alkoxide group is 0 to 2 mol, preferably 0 to 1.5 mol, more preferably 0 to 1 mol, and particularly preferably 0 to 0.5 mol. When alcohol is used as the solvent, it is also preferred that substantially no water is added.

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

The metal chelate compound can be suitably used without particular limitation as long as it has a metal selected from Zr, Ti or Al as a central metal. Within this category, two or more metal chelate compounds may be used in combination. Specific examples of the metal chelate compound used in the present invention include tri-n-butoxyethylacetoacetate zirconium, di-n-butoxybis (ethylacetoacetate) zirconium, n-butoxytris (ethylacetoacetate) zirconium, tetrakis (n Zirconium chelate compounds such as -propyl acetoacetate) zirconium, tetrakis (acetylacetoacetate) zirconium, tetrakis (ethylacetoacetate) zirconium; diisopropoxy bis (ethylacetoacetate) titanium, diisopropoxy bis (acetylacetate) titanium , Titanium chelate compounds such as diisopropoxy bis (acetylacetone) titanium; diisopropoxyethyl acetoacetate aluminum, diiso Ropoxyacetylacetonate aluminum, isopropoxybis (ethylacetoacetate) aluminum, isopropoxybis (acetylacetonate) aluminum, tris (ethylacetoacetate) aluminum, tris (acetylacetonato) aluminum, monoacetylacetonate bis ( Examples include aluminum chelate compounds such as ethyl acetoacetate) aluminum.
Among these metal chelate compounds, tri-n-butoxyethyl acetoacetate zirconium, diisopropoxybis (acetylacetonato) titanium, diisopropoxyethyl acetoacetate aluminum, and tris (ethyl acetoacetate) aluminum are preferable. These metal chelate compounds can be used individually by 1 type or in mixture of 2 or more types. Moreover, the partial hydrolyzate of these metal chelate compounds can also be used.

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

[High (medium) refractive index layer]
Next, the high (medium) refractive index layer will be described.
When a high refractive index layer is used in the present invention, the refractive index is preferably 1.65 to 2.40, and more preferably 1.70 to 2.20. When the middle refractive index layer is used, the refractive index is adjusted to be a value between the refractive index of the low refractive index layer and the refractive index of the high refractive index layer. The refractive index of the middle refractive index layer is preferably 1.55 to 1.80. The haze of the high refractive index layer and the medium refractive index layer is preferably 3% or less.

  In the high refractive index layer and the medium refractive index layer of the present invention, a cured product of a composition in which inorganic fine particles having a high refractive index are dispersed in the monomer and initiator exemplified in the hard coat layer and an organically substituted silicon compound. Is preferably used. As the inorganic fine particles, metal (eg, aluminum, titanium, zirconium, antimony) oxides are preferable, and from the viewpoint of refractive index, titanium dioxide fine particles are most preferable. In the case of using a monomer and an initiator, a medium refractive index layer or a high refractive index layer having excellent scratch resistance and adhesion can be formed by curing the monomer by a polymerization reaction using active energy rays or heat after coating. The average particle size of the inorganic fine particles is preferably 10 to 100 nm.

  As the titanium dioxide fine particles, inorganic fine particles mainly containing titanium dioxide containing at least one element selected from cobalt, aluminum, and zirconium are particularly preferable. The main component means a component having the largest content (mass%) among the components constituting the particles. The inorganic fine particles mainly composed of titanium dioxide in the present invention preferably have a refractive index of 1.90 to 2.80, more preferably 2.10 to 2.80, and 2.20 to 2.80. 80 is most preferred. The mass average diameter of primary particles of inorganic fine particles mainly composed of titanium dioxide is preferably 1 to 200 nm, more preferably 1 to 150 nm, still more preferably 1 to 100 nm, and particularly preferably 1 to 80 nm.

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

  By containing at least one element selected from Co (cobalt), Al (aluminum) and Zr (zirconium) in the inorganic fine particles mainly composed of titanium dioxide, the photocatalytic activity of titanium dioxide can be suppressed, The weather resistance of the high refractive index layer and the medium refractive index layer of the present invention can be improved. A particularly preferable element is Co (cobalt). It is also preferable to use two or more types in combination.

<Dispersant>
A dispersant can be used for dispersing inorganic fine particles mainly composed of titanium dioxide used in the high refractive index layer and the medium refractive index layer of the present invention. In order to disperse the inorganic fine particles mainly composed of titanium dioxide of the present invention, it is particularly preferable to use a dispersant having an anionic group. As the anionic group, a group having an acidic proton such as a carboxyl group, a sulfonic acid group (and a sulfo group), a phosphoric acid group (and a phosphono group), or a sulfonamide group, or a salt thereof is effective. A sulfonic acid group, a phosphoric acid group and a salt thereof are preferable, and a carboxyl group and a phosphoric acid group are particularly preferable. The number of anionic groups contained in the dispersant per molecule may be one or more. A plurality of anionic groups may be contained for the purpose of further improving the dispersibility of the inorganic fine particles. The average number is preferably 2 or more, more preferably 5 or more, and particularly preferably 10 or more. Moreover, the anionic group contained in a dispersing agent may contain multiple types in 1 molecule.

  The dispersant preferably further contains a crosslinkable or polymerizable functional group. Crosslinkable or polymerizable functional groups include ethylenically unsaturated groups (for example, (meth) acryloyl groups, allyl groups, styryl groups, vinyloxy groups, etc.) that can undergo addition reactions and polymerization reactions with radical species, and cationic polymerizable groups (epoxies). Groups, oxatanyl groups, vinyloxy groups, etc.), polycondensation reactive groups (hydrolyzable silyl groups, etc., N-methylol groups) and the like, and functional groups having an ethylenically unsaturated group are preferred. A preferred dispersant used for dispersing inorganic fine particles mainly composed of titanium dioxide used in the high refractive index layer of the present invention has an anionic group and a crosslinkable or polymerizable functional group, and the crosslinkable or polymerizable functional group. It is a dispersant having a group in the side chain. The weight average molecular weight (Mw) of the dispersant having an anionic group and a crosslinkable or polymerizable functional group and having the crosslinkable or polymerizable functional group in the side chain is not particularly limited, but may be 1000 or more. preferable. The more preferable mass average molecular weight (Mw) of the dispersant is 2000 to 1000000, more preferably 5000 to 200000, and particularly preferably 10000 to 100000.

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

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

  The inorganic fine particles are dispersed using a disperser. Examples of dispersers include sand grinder mills (eg, pinned bead mills), high speed impeller mills, pebble mills, roller mills, attritors and colloid mills. A sand grinder mill and a high-speed impeller mill are particularly preferred. Further, preliminary dispersion processing may be performed. Examples of the disperser used for the preliminary dispersion treatment include a ball mill, a three-roll mill, a kneader, and an extruder. The inorganic fine particles are preferably made as fine as possible in the dispersion medium, and the mass average diameter is 1 to 200 nm. Preferably it is 5-150 nm, More preferably, it is 10-100 nm, Most preferably, it is 10-80 nm. By refining the inorganic fine particles to 200 nm or less, a high refractive index layer and a medium refractive index layer that do not impair transparency can be formed.

  The high refractive index layer and medium refractive index layer used in the present invention are preferably a binder precursor (for example, described later) required for forming a matrix in a dispersion liquid in which inorganic fine particles are dispersed in a dispersion medium as described above. Active energy ray-curable polyfunctional monomers and polyfunctional oligomers), photopolymerization initiators, etc. are added to form a coating composition for forming a high refractive index layer and a medium refractive index layer, and a high refractive index layer on a transparent support. In addition, it is preferable to form by applying a coating composition for forming a medium refractive index layer and curing it by a crosslinking reaction or a polymerization reaction of an active energy ray-curable compound (for example, a polyfunctional monomer or a polyfunctional oligomer).

  Furthermore, it is preferable to cause the binder of the high refractive index layer and the medium refractive index layer to undergo a crosslinking reaction or a polymerization reaction with the dispersant simultaneously with or after the coating of the layer. The binder of the high refractive index layer and the medium refractive index layer produced in this way is, for example, a binder or active energy ray-curable polyfunctional monomer or polyfunctional oligomer that undergoes crosslinking or polymerization reaction to form a binder. In this form, the anionic group of the dispersant is incorporated. Furthermore, the binder of the high refractive index layer and the medium refractive index layer has a function in which the anionic group maintains the dispersion state of the inorganic fine particles, and the crosslinked or polymerized structure imparts a film forming ability to the binder and contains the inorganic fine particles. To improve the physical strength, chemical resistance and weather resistance of the high refractive index layer and medium refractive index layer.

  The functional group of the active energy ray-curable polyfunctional monomer or polyfunctional oligomer is preferably a light, electron beam, or radiation polymerizable group, and among them, a photopolymerizable functional group is preferable. Examples of the photopolymerizable functional group include unsaturated polymerizable functional groups such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group. Among them, a (meth) acryloyl group is preferable. In the present specification, descriptions such as “(meth) acrylate” and “(meth) acryloyl” mean “acrylate or methacrylate” and “acryloyl or methacryloyl”.

  Specific examples of the photopolymerizable polyfunctional monomer having a photopolymerizable functional group include those of alkylene glycols such as neopentyl glycol acrylate, 1,6-hexanediol di (meth) acrylate, propylene glycol di (meth) acrylate (meta ) Acrylic acid diesters; (Meth) acrylic of polyoxyalkylene glycols such as triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate Acid diesters;

  (Meth) acrylic acid diesters of polyhydric alcohols such as pentaerythritol di (meth) acrylate; 2,2-bis {4- (acryloxy-diethoxy) phenyl} propane, 2-bis {4- (acryloxy-poly) (Meth) acrylic acid diesters of ethylene oxide or propylene oxide adducts such as propoxy) phenyl} propane; and the like.

  Furthermore, epoxy (meth) acrylates, urethane (meth) acrylates, and polyester (meth) acrylates are also preferably used as the photopolymerizable polyfunctional monomer.

  Among these, esters of polyhydric alcohol and (meth) acrylic acid are preferable. More preferably, a polyfunctional monomer having 3 or more (meth) acryloyl groups in one molecule is preferable. Specifically, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, 1,2,4-cyclohexanetetra (meth) acrylate, glycerol triacrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol Tri (meth) acrylate, dipentaerythritol triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tripentaerythritol triacrylate, tripentaerythritol hexatriacrylate, etc. Can be mentioned.

  Two or more polyfunctional monomers may be used in combination. It is preferable to use a photopolymerization initiator for the polymerization reaction of the photopolymerizable polyfunctional monomer. As the photopolymerization initiator, a photoradical polymerization initiator and a photocationic polymerization initiator are preferable, and a photoradical polymerization initiator is particularly preferable. Examples of the photo radical polymerization initiator include acetophenones, benzophenones, Michler's benzoylbenzoate, α-amyloxime ester, tetramethylthiuram monosulfide, and thioxanthones.

  As a commercially available photo radical polymerization initiator, Kayacure (DETX-S, BP-100, BDMK, CTX, BMS, 2-EAQ, ABQ, CPTX, EPD, ITX, QTX, BTC, manufactured by Nippon Kayaku Co., Ltd. MCA, etc.), Irgacure (651, 184, 500, 907, 369, 1173, 2959, 4265, 4263, etc.) manufactured by Ciba Specialty Chemicals Co., Ltd., Esacure (KIP100F, KB1, EB3, BP, manufactured by Sartomer) X33, KT046, KT37, KIP150, TZT) and the like.

  In particular, photocleavable photoradical polymerization initiators are preferred. The photocleavable photoradical polymerization initiator is described in the latest UV curing technology (P.159, issuer; Kazuhiro Takashiro, publisher; Technical Information Association, Inc., published in 1991). Examples of commercially available photocleavable photoradical polymerization initiators include Irgacure (651, 184, 907) manufactured by Ciba Specialty Chemicals.

  It is preferable to use a photoinitiator in the range of 0.1-15 mass parts with respect to 100 mass parts of polyfunctional monomers, More preferably, it is the range of 1-10 mass parts. In addition to the photopolymerization initiator, a photosensitizer may be used. Specific examples of the photosensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, Michler's ketone and thioxanthone. Examples of commercially available photosensitizers include Kayacure (DMBI, EPA) manufactured by Nippon Kayaku Co., Ltd. The photopolymerization reaction is preferably performed by ultraviolet irradiation after the high refractive index layer is applied and dried. The high refractive index layer used in the present invention may contain the compound represented by the general formula (A) and / or a derivative compound thereof.

  In order to construct an antireflection film by constructing a low refractive index layer on a high refractive index layer, the refractive index of the high refractive index layer is preferably 1.55 to 2.40, more preferably It is 1.60 to 2.20, more preferably 1.65 to 2.10, and most preferably 1.80 to 2.00.

  In addition to the above components (inorganic fine particles, polymerization initiators, photosensitizers, etc.), the high refractive index layer includes resins, surfactants, antistatic agents, coupling agents, thickeners, anti-coloring agents, and coloring. Agents (pigments, dyes), antifoaming agents, leveling agents, flame retardants, ultraviolet absorbers, infrared absorbers, adhesion-imparting agents, polymerization inhibitors, antioxidants, surface modifiers, conductive metal particles, etc. It can also be added.

  In the formation of the high refractive index layer, the crosslinking reaction or polymerization reaction of the active energy ray-curable compound is preferably carried out in an atmosphere having an oxygen concentration of 10% by volume or less. By forming the high refractive index layer in an atmosphere having an oxygen concentration of 10% by volume or less, the physical strength, chemical resistance, and weather resistance of the high refractive index layer, and further, the high refractive index layer and the high refractive index layer are adjacent to each other. Adhesion with the layer can be improved. Preferably, the active energy ray-curable compound is formed by a crosslinking reaction or a polymerization reaction in an atmosphere having an oxygen concentration of 6% by volume or less, more preferably an oxygen concentration of 4% by volume or less, particularly preferably an oxygen concentration. 2% by volume or less, most preferably 1% by volume or less.

  In addition, when an antireflection film is applied to a liquid crystal display device, an undercoat layer to which particles having an average particle diameter of 0.1 to 10 μm are added is newly constructed or a hard coat layer for the purpose of improving viewing angle characteristics. The above particles can be added to form a light scattering hard coat layer. The average particle diameter of the particles is preferably 0.2 to 5.0 μm, more preferably 0.3 to 4.0 μm, and particularly preferably 0.5 to 3.5 μm.

The refractive index of the particles is preferably 1.35 to 1.80, more preferably 1.40 to 1.75, and still more preferably 1.45 to 1.75. The narrower the particle size distribution, the better. The S value indicating the particle size distribution of the particles is represented by the following formula, preferably 1.5 or less, more preferably 1.0 or less, and particularly preferably 0.7 or less.
S = [D (0.9) -D (0.1)] / D (0.5)
D (0.1): Particle size equivalent to 10% of the integrated value of the volume converted particle size D (0.5): Particle size equivalent to 50% of the integrated value of the volume converted particle size D (0.9): Volume converted particle Diameter equivalent to 90% of the integrated diameter

  The difference in refractive index between the refractive index of the particles and the refractive index of the undercoat layer is preferably 0.02 or more. More preferably, the difference in refractive index is 0.03 to 0.5, more preferably the difference in refractive index is 0.05 to 0.4, and particularly preferably the difference in refractive index is 0.07 to 0.3. . Examples of the particles added to the undercoat layer include inorganic particles and organic particles described in the antiglare layer. The undercoat layer is preferably constructed between the hard coat layer and the transparent support. It can also serve as a hard coat layer. When particles having an average particle size of 0.1 to 10 μm are added to the undercoat layer, the haze of the undercoat layer is preferably 3 to 60%. More preferably, it is 5 to 50%, further preferably 7 to 45%, particularly preferably 10 to 40%.

  As the transparent support of the antireflection film of the present invention, a plastic film is preferably used. Polymers that form plastic films include cellulose esters (eg, triacetyl cellulose, diacetyl cellulose), polyamides, polycarbonates, polyesters (eg, polyethylene terephthalate, polyethylene naphthalate), polystyrenes, polyolefins, norbornene resins (Arton: trade names) , Manufactured by JSR Corporation), amorphous polyolefin (ZEONEX: trade name, manufactured by Nippon Zeon Co., Ltd.), and the like. Of these, triacetyl cellulose, polyethylene terephthalate, and polyethylene naphthalate are preferable, and triacetyl cellulose is particularly preferable. When the antireflection film of the present invention is used in a liquid crystal display device, it is disposed on the outermost surface of the display by means such as providing an adhesive layer on one side. When the transparent support is triacetylcellulose, triacetylcellulose is used as a protective film for protecting the polarizing layer of the polarizing plate. Therefore, it is preferable in terms of cost to use the antireflection film of the present invention as it is for the protective film. .

<Transparent substrate>
Unless the antireflection film is directly provided on the CRT image display surface or the lens surface, the antireflection film preferably has a transparent substrate (transparent support). The light transmittance of the transparent substrate is preferably 80% or more, and more preferably 86% or more. The haze of the transparent substrate is preferably 2.0% or less, and more preferably 1.0% or less. The refractive index of the transparent substrate is preferably 1.4 to 1.7. As the transparent substrate, a plastic film is preferable to a glass plate. Examples of plastic film materials include cellulose esters, polyamides, polycarbonates, polyesters (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, polymethyl Methacrylate and polyether ketone are included. Cellulose ester, polycarbonate, polyethylene terephthalate and polyethylene naphthalate are preferred. In particular, when used in a liquid crystal display device, a cellulose acylate film is preferable, and cellulose acylate is produced by esterification from cellulose. The particularly preferable cellulose described above is not necessarily usable as it is, but is used by refining linter, kenaf and pulp.

  In the present invention, cellulose acylate means a fatty acid ester of cellulose, and a lower fatty acid ester is particularly preferable. Furthermore, a fatty acid ester film of cellulose is preferable. Lower fatty acid means a fatty acid having 6 or less carbon atoms. A cellulose acylate having 2 to 4 carbon atoms is preferred. Cellulose acetate is particularly preferred. It is also preferable to use mixed fatty acid esters such as cellulose acetate propionate and cellulose acetate butyrate.

  The viscosity average degree of polymerization (DP) of cellulose acylate is preferably 250 or more, and more preferably 290 or more. Cellulose acylate preferably has a narrow molecular weight distribution of Mw / Mn (Mw is a mass average molecular weight, Mn is a number average molecular weight) by gel permeation chromatography. A specific value of Mw / Mn is preferably 1.0 to 5.0. More preferably, it is 1.0-3.0, Most preferably, it is 1.0-2.0. As the transparent substrate of the present invention, it is preferable to use cellulose acylate having an acetylation degree of 55.0 to 62.5%. The acetylation degree is more preferably 57.0 to 62.0%, and particularly preferably 59.0 to 61.5%. The degree of acetylation means the amount of bound acetic acid per unit mass of cellulose. The degree of acetylation is determined by measurement and calculation of the degree of acylation in ASTM: D-817-91 (testing method for cellulose acylate, etc.).

  In cellulose acylate, the hydroxyl groups at the 2-position, 3-position and 6-position of cellulose are not evenly substituted, but the substitution degree at the 6-position tends to be small. In the cellulose acylate used in the present invention, it is preferable that the degree of substitution at the 6-position of cellulose is the same or greater than that at the 2- and 3-positions. The ratio of the substitution degree at the 6-position to the total substitution degree at the 2-position, the 3-position, and the 6-position is preferably 30 to 40%, more preferably 31 to 40%, and more preferably 32 to 40%. Most preferably it is. In addition, the cellulose acylate film substantially free of halogenated hydrocarbons such as dichloromethane and the process for producing the same are disclosed in the JIII Journal of Technical Disclosure (Publication No. 2001-1745, published on March 15, 2001; The cellulose acylate described here can also be preferably used in the present invention.

For transparent substrates, various additives are used to adjust the film's mechanical properties (film strength, curl, dimensional stability, slipperiness, etc.) and durability (wet heat resistance, weather resistance, etc.). Can be used. For example, plasticizers (phosphate esters, phthalate esters, esters of polyols and fatty acids, etc.), UV inhibitors (eg, hydroxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, cyanoacrylate compounds) Etc.), deterioration inhibitors (eg, antioxidants, peroxide decomposers, radical inhibitors, metal deactivators, acid scavengers, amines, etc.), fine particles (eg, SiO ₂ , Al ₂ O ₃ , TiO ₂₎ BaSO ₄ , CaCO ₃ , MgCO ₃ , talc, kaolin, etc.), release agents, antistatic agents, infrared absorbers, and the like. These details are disclosed in the Invention Association Public Technique No. 2001-1745 (issued March 15, 2001, Invention Association), p. Materials described in detail in 17-22 are preferably used.
The amount of the additive used is preferably 0.01 to 20% by mass of the transparent substrate, and more preferably 0.05 to 10% by mass.

  Surface treatment may be performed on the transparent substrate. Examples of the surface treatment include chemical treatment, mechanical treatment, corona discharge treatment, flame treatment, ultraviolet irradiation treatment, high frequency treatment, glow discharge treatment, active plasma treatment, laser treatment, mixed acid treatment and ozone oxidation treatment. Specifically, for example, Invention Association Public Technique No. 2001-1745 (issued March 15, 2001) p. The content described in 30-31, the content described in JP 2001-9973 A, and the like can be given. Preferably, glow discharge treatment, ultraviolet irradiation treatment, corona discharge treatment and flame treatment, and more preferably glow discharge treatment and ultraviolet treatment.

  In the antireflection film of the present invention, it is preferable to add an inorganic filler to each layer as appropriate for the purpose of improving the film strength. The inorganic filler added to each layer may be the same or different, and it is preferable that the type, addition amount, etc. are appropriately adjusted according to the required performance such as refractive index, film strength, film thickness, and coating property of each layer. . The shape of the inorganic filler used in the present invention is not particularly limited, and for example, any of a spherical shape, a plate shape, a fiber shape, a rod shape, an irregular shape, a hollow shape, and the like are preferably used. preferable. Further, the kind of the inorganic filler is not particularly limited, but an amorphous one is preferably used, and is preferably made of a metal oxide, nitride, sulfide or halide. Particularly preferred.

  As metal atoms of the metal oxide, Na, K, Mg, Ca, Ba, Al, Zn, Fe, Cu, Ti, Sn, In, W, Y, Sb, Mn, Ga, V, Nb, Ta, Examples include Ag, Si, B, Bi, Mo, Ce, Cd, Be, Pb, and Ni. In order to obtain a transparent cured film, the average particle diameter of the inorganic filler is preferably set to a value within the range of 0.001 to 0.2 μm, more preferably 0.001 to 0.1 μm, and still more preferably. 0.001 to 0.06 μm. Here, the average particle diameter of the particles is measured by a Coulter counter. Although the usage method of the inorganic filler in this invention is not restrict | limited in particular, For example, it can use in a dry state or can also be used in the state disperse | distributed to water or the organic solvent. In the present invention, it is also preferable to use a dispersion stabilizer in combination for the purpose of suppressing aggregation and sedimentation of the inorganic filler. As the dispersion stabilizer, polyvinyl alcohol, polyvinyl pyrrolidone, cellulose derivative, polyamide, phosphate ester, polyether, surfactant, silane coupling agent, titanium coupling agent and the like can be used. In particular, a silane coupling agent is preferable because the film after curing is strong. Although the addition amount of the silane coupling agent as a dispersion stabilizer is not particularly limited, for example, the value is preferably 1 part by mass or more with respect to 100 parts by mass of the inorganic filler. Also, the method of adding the dispersion stabilizer is not particularly limited, but a hydrolyzed one can be added, or a dispersion stabilizer silane coupling agent and an inorganic filler are mixed. Thereafter, a method of further hydrolysis and condensation can be employed, but the latter is more preferable. The inorganic filler suitable for each layer will be described later.

[Hard coat layer]
The hard coat layer of the antireflection film of the present invention will be described below.
The hard coat layer is formed from a binder for imparting hard coat properties, mat particles for imparting anti-glare properties as necessary, and an inorganic filler for increasing the refractive index, preventing crosslinking shrinkage, and increasing the strength. Is done. The binder is preferably a polymer having a saturated hydrocarbon chain or a polyether chain as the main chain, and more preferably a polymer having a saturated hydrocarbon chain as the main chain. The binder polymer preferably has a crosslinked structure. As the binder polymer having a saturated hydrocarbon chain as a main chain, a polymer of an ethylenically unsaturated monomer is preferable. As the binder polymer having a saturated hydrocarbon chain as the main chain and having a crosslinked structure, a (co) polymer of monomers having two or more ethylenically unsaturated groups is preferable. In order to obtain a high refractive index, the monomer structure preferably contains an aromatic ring or at least one atom selected from halogen atoms other than fluorine, sulfur atoms, phosphorus atoms, and nitrogen atoms.

  Examples of the monomer having two or more ethylenically unsaturated groups include esters of polyhydric alcohol and (meth) acrylic acid (eg, ethylene glycol di (meth) acrylate, 1,4-dichlorohexane diacrylate, 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, 1,3,5-cyclohexanetriol triacrylate, polyurethane polyacrylate, polyester polyacrylate), vinylbenzene and derivatives thereof (Eg, 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester, 1,4-divinylcyclohexanone), vinyl sulfone (eg, divinyl sulfone), acrylamide (eg, methylenebisacrylamide) and methacryl Amides are mentioned.

  Specific examples of the high refractive index monomer include bis (4-methacryloylthiophenyl) sulfide, vinyl naphthalene, vinyl phenyl sulfide, 4-methacryloxyphenyl-4′-methoxyphenyl thioether, and the like.

  Polymerization of these monomers having an ethylenically unsaturated group can be performed by irradiation with active energy rays or heating in the presence of a photo radical initiator or a thermal radical initiator. Accordingly, a coating liquid containing a monomer having an ethylenically unsaturated group, a photo radical initiator or a thermal radical initiator, mat particles and an inorganic filler is prepared, and the coating liquid is applied on a transparent support and then an active energy ray or It can be cured by a polymerization reaction by heat to form an antireflection film.

  The polymer having a polyether as the main chain is preferably a ring-opening polymer of a polyfunctional epoxy compound. The ring-opening polymerization of the polyfunctional epoxy compound can be performed by irradiation with active energy rays or heating in the presence of a photoacid generator or a thermal acid generator. Therefore, a coating liquid containing a polyfunctional epoxy compound, a photoacid generator or a thermal acid generator, matte particles and an inorganic filler is prepared, and the coating liquid is applied onto a transparent support and then subjected to a polymerization reaction by active energy rays or heat. Can be cured to form an antireflection film.

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

The hard coat layer contains matte particles having an average particle diameter of 1 to 10 μm, preferably 1.5 to 7.0 μm, for example, inorganic compound particles or resin particles, if necessary. Specific examples of the mat particles preferably include inorganic particles such as silica particles and TiO ₂ particles; resin particles such as crosslinked acrylic particles, crosslinked styrene particles, melamine resin particles, and benzoguanamine resin particles. Of these, crosslinked styrene particles are preferred. As the shape of the mat particle, either a true sphere or an indefinite shape can be used. Further, two or more different kinds of mat particles may be used in combination. The mat particles are contained in the antiglare hard coat layer so that the amount of mat particles in the formed antiglare hard coat layer is preferably 10 to 1000 mg / m ² , more preferably 30 to 100 mg / m ^2. Is done. In a particularly preferred embodiment, cross-linked styrene particles are used as mat particles, and the cross-linked styrene particles having a particle size larger than one half of the film thickness of the hard coat layer occupy 40 to 100% of the entire cross-linked styrene particles. It is an aspect. Here, the particle size distribution of the mat particles is measured by a Coulter counter method, and the measured distribution is converted into a particle number distribution.

The hard coat layer is made of an oxide of at least one metal selected from titanium, zirconium, aluminum, indium, zinc, tin, and antimony, in addition to the above mat particles, in order to increase the refractive index of the layer. Therefore, it is preferable that an inorganic filler having an average particle diameter of 0.001 to 0.2 μm or less, preferably 0.001 to 0.1 μm, more preferably 0.001 to 0.06 μm or less is contained. Specific examples of the inorganic filler used for the hard coat layer include TiO ₂ , ZrO ₂ , Al ₂ O ₃ , In ₂ O ₃ , ZnO, SnO ₂ , Sb ₂ O ₃ and ITO. TiO ₂ and ZrO ₂ are particularly preferable from the viewpoint of increasing the refractive index. The surface of the inorganic filler is preferably subjected to a silane coupling treatment or a titanium coupling treatment, and a surface treatment agent having a functional group capable of reacting with a binder species on the filler surface is preferably used. The amount of these inorganic fillers added is preferably 10 to 90% of the total mass of the hard coat layer, more preferably 20 to 80%, and particularly preferably 30 to 75%. Such a filler does not scatter because the particle size is sufficiently smaller than the wavelength of light, and a dispersion in which the filler is dispersed in a binder polymer behaves as an optically uniform substance.

  The total refractive index of the mixture of binder and inorganic filler of the hard coat layer of the present invention is preferably 1.57 to 2.00, more preferably 1.60 to 1.80. In order to make the refractive index within the above range, the kind and amount ratio of the binder and the inorganic filler may be appropriately selected. How to select can be easily known experimentally in advance.

  The film thickness of the hard coat layer is preferably 1 to 10 μm, more preferably 1.2 to 6 μm.

  The antireflection film of the present invention thus formed has a haze value of 3 to 20%, preferably 4 to 15%, and an average reflectance of 450 nm to 650 nm is preferably 1.8% or less, preferably Is 1.5% or less. When the antireflection film of the present invention has a haze value and an average reflectance in the above range, good antiglare properties and antireflection properties can be obtained without causing deterioration of the transmitted image.

Each layer of the antireflection film having a multilayer structure is formed by a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a die coating method, a wire bar coating method, a gravure coating method or an extrusion coating method (US Pat. No. 2,681,294). According to the description, it can be formed by coating, but it is preferable to apply a gravure coating method because a coating solution with a small coating amount such as each layer of the antireflection film can be applied with high film thickness uniformity. Among the gravure coating methods, the micro gravure method has a high film thickness uniformity and is more preferable. Moreover, it is more preferable to apply by a die coating method, and it is particularly preferable to apply using a new die coater described later. Two or more layers may be applied simultaneously. The methods for simultaneous application are described in US Pat. Nos. 2,761,791, 2,941,898, 3,508,947, and 3,526,528 and Yuji Harasaki, Coating Engineering, page 253, Asakura Shoten (1973).
In the antireflection film of the present invention, at least the high refractive index layer and the low refractive index layer are laminated, so that bright spot defects are easily noticeable when foreign matters such as dust and dust are present. The bright spot defect in the present invention is a defect that can be visually observed by reflection on the coating film, and can be detected by an operation such as black coating on the back surface of the antireflection film after coating. The bright spot defects that can be visually observed are generally 50 μm or more. When there are many bright spot defects, the yield at the time of manufacture will fall and a large-area antireflection film cannot be manufactured.
In the antireflection film of the present invention, the number of bright spot defects is 20 or less per square meter, preferably 10 or less, more preferably 5 or less, and particularly preferably 1 or less.

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

The above process may be performed every time each layer is formed, or a plurality of coating units-drying chambers-radiation curing units-thermosetting chambers may be provided to form each layer continuously. In view of the above, it is preferable to continuously form each layer. An example of the configuration of an apparatus for continuously applying each layer is shown in FIG. The apparatus has an appropriate number of film forming units 100, 200, 300, and 400 installed between the step 110 of continuously feeding the roll-shaped support film and the step 120 of winding the roll-shaped support film. Is. The apparatus shown in FIG. 2 is an example of a configuration in which four layers are continuously applied without winding up, but it is of course possible to change the number of film forming units in accordance with the layer configuration. The film forming unit 100 includes a process 101 for applying a coating liquid, a process 102 for drying a coating film, and a process 103 for curing the coating film.
Using an apparatus in which three film forming units are installed, a roll-shaped support film coated with the hard coat layer is continuously fed, and a medium refractive index layer, a high refractive index layer, and a low refractive index layer are provided for each. It is more preferable to wind up after sequentially coating with the film forming unit. Using the apparatus shown in FIG. 2 in which four film forming units are installed, the roll-shaped support film is continuously fed out, and the hard coat layer More preferably, the intermediate refractive index layer, the high refractive index layer, and the low refractive index layer are sequentially coated on each film forming unit and then wound.

  In order to produce an antireflection film with few bright spot defects in the present invention, it is necessary to precisely control the degree of dispersion of the high refractive index ultrafine particles in the coating material for the high refractive index layer, and to perform a fine filtration operation of the coating liquid. Can be mentioned. At the same time, each layer forming the antireflection layer is subjected to a dusting process on the film before the coating process in the coating unit and the drying process performed in the drying chamber are performed in a clean air atmosphere and before the coating is performed. It is preferable that dust is sufficiently removed. The air cleanliness of the coating process and the drying process is desirably class 10 (353 particles / 0.5 m or more / (cubic meter) or less) based on the standard of air cleanliness in the US Federal Standard 209E. Preferably it is class 1 (35.5 particles / (cubic meter) or less) having a particle size of 0.5 μm or more. Moreover, it is more preferable that the degree of air cleanliness is high also in the feeding and winding parts other than the coating-drying process.

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

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

[Dispersion medium for coating]
The dispersion medium for coating is not particularly limited. You may use individually or in mixture of 2 or more types. Preferred dispersion media include aromatic hydrocarbons such as toluene, xylene and styrene, chlorinated aromatic hydrocarbons such as chlorobenzene and orthodichlorobenzene, methane derivatives such as monochloromethane, ethane derivatives such as monochloroethane, and the like. Chlorinated aliphatic hydrocarbons, alcohols such as methanol, isopropyl alcohol and isobutyl alcohol, esters such as methyl acetate and ethyl acetate, ethers such as ethyl ether and 1,4-dioxane, acetone, methyl ethyl ketone, methyl isobutyl ketone, Examples include ketones such as cyclohexanone, glycol ethers such as ethylene glycol monomethyl ether, alicyclic hydrocarbons such as cyclohexane, aliphatic hydrocarbons such as normal hexane, and mixtures of aliphatic or aromatic hydrocarbons. Among these solvents, a dispersion medium for coating prepared by alone or mixing two or more ketones is particularly preferable.

[Coating liquid properties]
In the coating method of the present invention, the upper limit speed at which coating is possible is greatly affected by the liquid physical properties, so it is necessary to control the liquid physical properties, particularly the viscosity and surface tension at the moment of coating.
The viscosity is preferably 2.0 [mPa · sec] or less, more preferably 1.5 [mPa · sec] or less, and most preferably 1.0 [mPa · sec] or less. Since there are some coating solutions whose viscosity changes depending on the shear rate, the above value indicates the viscosity at the shear rate at the moment of coating. When a thixotropic agent is added to the coating solution and the coating solution is subjected to high shear, the viscosity is low, and when the coating solution is hardly sheared, if the viscosity is high, unevenness during drying is less likely to occur.
Moreover, although it is not a liquid physical property, the quantity of the coating liquid apply | coated to a transparent support body also affects the upper limit speed | rate which can be apply | coated. The amount of the coating solution applied to the transparent support is preferably 2.0 to 5.0 [ml / m ² ]. Increasing the amount of the coating liquid applied to the transparent support is preferable because the upper limit of the application rate can be increased, but if the amount of the coating liquid applied to the transparent support is increased too much, the load on drying increases. It is preferable to determine the optimal amount of coating liquid to be applied to the transparent support depending on the liquid formulation and process conditions.
The surface tension is preferably in the range of 15 to 36 [mN / m]. It is preferable to reduce the surface tension by adding a leveling agent or the like because unevenness during drying is suppressed. On the other hand, if the surface tension is too low, the upper limit speed at which coating can be performed is reduced. Therefore, the range of 17 [mN / m] to 32 [mN / m] is more preferable, and 19 [mN / m] to 26 [ mN / m] is more preferable.

[filtration]
The coating solution used for coating is preferably filtered before coating. As a filter for filtration, it is preferable to use a filter having a pore diameter as small as possible within a range in which components in the coating solution are not removed. For filtration, a filter having an absolute filtration accuracy of 0.1 to 10 μm is used, and a filter having an absolute filtration accuracy of 0.1 to 5 μm is preferably used. The thickness of the filter is preferably 0.1 to 10 mm, and more preferably 0.2 to 2 mm. In that case, the filtration pressure is preferably 1.5 MPa or less, more preferably 1.0 MPa or less, and further preferably 0.2 MPa or less.
The filtration filter member is not particularly limited as long as it does not affect the coating solution. Specifically, the same thing as the filtration member of the wet dispersion of an inorganic compound mentioned above is mentioned.
Further, it is also preferable that the filtered coating solution is ultrasonically dispersed immediately before coating to assist defoaming and dispersion holding of the dispersion.

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

As a method of reducing the oxygen concentration to 10% by volume or less, it is preferable to replace the atmosphere (nitrogen concentration of about 79% by volume, oxygen concentration of about 21% by volume) with another gas, particularly preferably replacement with nitrogen (nitrogen purge). It is to be.
The light source for light irradiation may be any ultraviolet light region or near-infrared light. Ultraviolet, high pressure, medium pressure, and low pressure mercury lamps, chemical lamps, carbon arc lamps, metal halide lamps may be used as ultraviolet light sources. Xenon lamps, sunlight, etc. Various available laser light sources having a wavelength of 350 to 420 nm may be irradiated as a multi-beam. Further, examples of the near-infrared light source include a halogen lamp, a xenon lamp, and a high-pressure sodium lamp. Various available laser light sources having a wavelength of 750 to 1400 nm may be irradiated in a multi-beam form.
When using a near-infrared light source, it may be used in combination with an ultraviolet light source, or may be irradiated from the substrate surface side opposite to the coating surface side. Film curing in the depth direction in the coating layer proceeds without delay with the vicinity of the surface, and a cured film in a uniform cured state is obtained.
Irradiation intensity of ultraviolet irradiation is preferably about 0.1~1000mW / cm ^2, irradiation amount on the coating film surface is preferably 10~1000mJ / cm ^2. Further, the temperature distribution of the coating film in the light irradiation step is preferably as uniform as possible, preferably within ± 3 ° C., and more preferably controlled within ± 1.5 ° C. Within this range, the polymerization reaction in the in-plane and in-layer depth directions of the coating film proceeds uniformly, which is preferable.

[Configuration of die coater]
FIG. 3 is a sectional view of a coater using a slot die embodying the present invention. The coater 10 is applied to the web W supported by the backup roll 11 and continuously applied from the slot die 13 as a bead 14a to form a coating film 14b on the web W.

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

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

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

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

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

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

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

Is preferably placed in the gap G _B between the back plate 40a and the web W is larger than the gap G _L between the end lip 17 and the web W of the slot die 13, beads vicinity due to the eccentricity of the backup roll 11 thereby The change in the degree of decompression can be suppressed. For example, when the gap G _L between the end lip 17 and the web W of the slot die 13 is 30μm or more 100μm or less, the gap G _B between the back plate 40a and the web W is preferably 100μm or 500μm or less.

[Material and accuracy]
The longer the length of the tip lip on the traveling direction side of the web in the web running direction, the more disadvantageous it is for bead formation.If this length varies between arbitrary locations in the slot die width direction, It becomes unstable. Therefore, it is preferable that the fluctuation width in the slot die width direction is within 20 μm.
Further, if the material of the tip lip of the slot die is made of a material such as stainless steel, the length of the slot die tip lip in the web running direction is 30 μm to 100 μm as described above. Even within this range, the accuracy of the tip lip cannot be satisfied. Therefore, in order to maintain a high processing accuracy, it is important to use a cemented carbide material as described in Japanese Patent No. 2810753. Specifically, at least the tip lip of the slot die is preferably made of a cemented carbide formed by bonding carbide crystals having an average particle size of 5 μm or less. Cemented carbides include carbide carbide particles such as tungsten carbide (hereinafter referred to as WC) bonded by a bonding metal such as cobalt, and other bonding metals include titanium, tantalum, niobium, and mixed metals thereof. Can also be used. The average particle size of the WC crystal is more preferably 3 μm or less.
In order to realize high-precision coating, the length of the land on the web traveling direction side of the tip lip and the variation in the slot die width direction of the gap with the web are also important factors. It is desirable to achieve a combination of these two factors, that is, straightness within a range in which the fluctuation range of the gap can be suppressed to some extent. Preferably, the straightness of the tip lip and the backup roll is set so that the fluctuation width of the gap in the slot die width direction is 5 μm or less.

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

  The polarizing plate of the present invention uses the antireflection film as at least one of the two protective films of the polarizing layer. By using the antireflection film of the present invention as the outermost layer, reflection of external light and the like can be prevented, and a polarizing plate excellent in scratch resistance, antifouling property and the like can be obtained. Moreover, in the polarizing plate of this invention, when an antireflection film serves as a protective film, manufacturing cost can be reduced.

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

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

  The VA mode liquid crystal cell includes (1) a narrowly defined VA mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied, and substantially horizontally when a voltage is applied (Japanese Patent Laid-Open No. Hei 2-). 176625 (in Japanese Patent Publication No. 176625), and (2) a liquid crystal cell (SID97, Digest of tech. Papers (Proceedings) 28 (1997) 845 in which the VA mode is converted into a multi-domain (MVA mode) for widening the viewing angle ), (3) A liquid crystal cell in a mode (n-ASM mode) in which rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied and twisted multi-domain alignment is applied when a voltage is applied (Preliminary collections 58-59 of the Japan Liquid Crystal Society) (1998)) and (4) SURVAVAL mode liquid crystal cells (announced at LCD International 98).

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

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

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

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

  (Synthesis of perfluoroolefin copolymer (1))

  Into a stainless steel autoclave with a stirrer of 100 ml, 40 ml of ethyl acetate, 14.7 g of hydroxyethyl vinyl ether and 0.55 g of dilauroyl peroxide were charged, and the inside of the system was deaerated and replaced with nitrogen gas. Furthermore, 25 g of hexafluoropropylene (HFP) was introduced into the autoclave and the temperature was raised to 65 ° C. The pressure when the temperature in the autoclave reached 65 ° C. was 0.53 MPa. The reaction was continued for 8 hours while maintaining the temperature, and when the pressure reached 0.31 MPa, the heating was stopped and the mixture was allowed to cool. When the internal temperature dropped to room temperature, unreacted monomers were driven out, the autoclave was opened, and the reaction solution was taken out. The obtained reaction solution was poured into a large excess of hexane, and the polymer was precipitated by removing the solvent by decantation. Further, this polymer was dissolved in a small amount of ethyl acetate and reprecipitated twice from hexane to completely remove the residual monomer. After drying, 28 g of polymer was obtained. Next, 20 g of the polymer was dissolved in 100 ml of N, N-dimethylacetamide, and 11.4 g of acrylic acid chloride was added dropwise under ice cooling, followed by stirring at room temperature for 10 hours. Ethyl acetate was added to the reaction solution, washed with water, the organic layer was extracted and concentrated, and the resulting polymer was reprecipitated with hexane to obtain 19 g of perfluoroolefin copolymer (1). The resulting polymer had a refractive index of 1.421.

(Preparation of sol solution a)
A stirrer, a reactor equipped with a reflux condenser, 120 parts of methyl ethyl ketone, 100 parts of acryloyloxypropyltrimethoxysilane (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.), diisopropoxyaluminum ethyl acetoacetate (trade name: Kerope EP) -12, manufactured by HOPE PHARMACEUTICAL CO., LTD.) After mixing and mixing, 30 parts of ion-exchanged water was added and reacted at 60 ° C. for 4 hours, and then cooled to room temperature to obtain sol solution a. The mass average molecular weight was 1600, and among the components higher than the oligomer component, the component having a molecular weight of 1000 to 20000 was 100%. Further, from the gas chromatography analysis, the raw material acryloyloxypropyltrimethoxysilane did not remain at all.

(Preparation of coating liquid A for hard coat layer)
PET-30 50.0 parts by mass Irgacure 184 2.0 parts by mass SX-350 (30%) 1.7 parts by mass Crosslinked acrylic-styrene particles (30%) 13.3 parts by mass FP-132 0.75 parts by mass KBM -5103 10.0 parts by mass Toluene 38.5 parts by mass

(Preparation of coating liquid B for hard coat layer)
Desolite Z7404 100 parts by mass (Zirconia fine particle-containing hard coat composition solution: manufactured by JSR Corporation)
DPHA (UV curable resin: manufactured by Nippon Kayaku Co., Ltd.) 31 parts by mass KBM-5103 10 parts by mass KE-P150 (1.5 μm silica particles: manufactured by Nippon Shokubai Co., Ltd.) 8.9 parts by mass MXS-300 ( 3 μm cross-linked PMMA particles: manufactured by Soken Chemical Co., Ltd.) 3.4 parts by mass MEK (methyl ethyl ketone) 29 parts by mass MIBK (methyl isobutyl ketone) 13 parts by mass

(Preparation of coating liquid C for hard coat layer)
750.0 parts by mass of trimethylolpropane triacrylate (TMPTA, manufactured by Nippon Kayaku Co., Ltd.), 270.0 parts by mass of poly (glycidyl methacrylate) having a mass average molecular weight of 15000, 730.0 parts by mass of methyl ethyl ketone, 500.0 cyclohexanone 50.0 parts by mass and 50.0 parts by mass of a photopolymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals Co., Ltd.) were added and stirred.

  The coating solutions A and B were filtered through a polypropylene filter having a pore size of 30 μm, and C was a pore size of 0.4 μm to prepare a coating solution for a hard coat layer.

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

Dispersant

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

(Preparation of coating liquid A for high refractive index layer)
To 469.8 parts by mass of the above-mentioned titanium dioxide dispersion A, 40.0 parts by mass of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.), a photopolymerization initiator (Irgacure 907) 3.3 parts by mass, manufactured by Ciba Specialty Chemicals Co., Ltd., 1.1 parts by mass of photosensitizer (Kayacure-DETX, manufactured by Nippon Kayaku Co., Ltd.), 526.2 parts by mass of methyl ethyl ketone, and cyclohexanone 459 .6 parts by mass was added and stirred. It filtered with the polypropylene filter with the hole diameter of 0.4 micrometer.

(Preparation of coating solution A for low refractive index layer)
DPHA 4.0 parts by mass Hollow silica (18.2%) 40.0 parts by mass Irgacure 907 0.2 parts by mass Sol solution a 6.2 parts by mass MEK 299.6 parts by mass

(Preparation of coating solution B for low refractive index layer)
DPHA 3.3 parts by mass Hollow silica (18.2%) 40.0 parts by mass RMS-033 0.7 parts by mass Irgacure 907 0.2 parts by mass Sol solution a 6.2 parts by mass MEK 299.6 parts by mass

(Preparation of coating solution C for low refractive index layer)
JTA113 (6%) 13.0 parts by mass MEK-ST-L 1.3 parts by mass Sol liquid a 0.6 parts by mass MEK 5.0 parts by mass Cyclohexanone 0.6 parts by mass

(Preparation of coating solution D for low refractive index layer)
JN7228A (6%) 13.0 parts by mass MEK-ST-L 1.3 parts by mass Sol solution a 0.6 parts by mass MEK 5.0 parts by mass Cyclohexanone 0.6 parts by mass

(Preparation of coating liquid E for low refractive index layer)
JN7228A (6%) 100.0 parts by mass MEK-ST 4.3 parts by mass MEK-ST-L 5.1 parts by mass Sol solution a 2.2 parts by mass MEK 15.0 parts by mass Cyclohexanone 3.6 parts by mass

(Preparation of coating solution F for low refractive index layer)
Exemplified compound: P-1 14.0 parts by mass X-22-164C 0.42 parts by mass Irgacure 907 0.7 parts by mass MIBK 84.7 parts by mass

(Preparation of coating solution G for low refractive index layer)
30 parts by mass of tetramethoxysilane and 240 parts by mass of methanol are put into a four-necked reaction flask and stirred while keeping the liquid temperature at 30 ° C. Then, an aqueous solution in which 2 parts by mass of nitric acid is added to 6 parts by mass of water is added. The mixture was stirred at 30 ° C. for 5 hours to obtain a siloxane oligomer alcohol solution (solution A). The relative molecular weight in terms of ethylene glycol / polyethylene oxide by GPC of the siloxane oligomer was 950.

  Separately, 300 parts by mass of methanol was added to a four-necked reaction flask, and then 30 parts by mass of oxalic acid was mixed with stirring. While heating and refluxing this solution, 30 parts by mass of tetramethoxysilane and 8 parts by mass of tridecafluorooctyltrimethoxysilane were added dropwise, heated under reflux for 5 hours, cooled, and fluorine having a fluoroalkyl structure and a polysiloxane structure. A solution of the compound (Solution B) was obtained.

  30 parts by mass of solution A and 100 parts by mass of solution B were stirred and mixed, and diluted with butyl acetate so that the solid content concentration in the mixed coating solution was 1% by mass, thereby obtaining coating solution G for low refractive index layer. .

(Preparation of coating solution H for low refractive index layer)
Solution A and solution B were prepared in the same manner as the coating solution G for the low refractive index layer. 30 parts by mass of solution A and 100 parts by mass of solution B were further added with 1 part by mass of hydrogen-terminated polydimethylsiloxane DMS-H21 (manufactured by Gelest). 80 parts by mass of hollow silica particles (18.2%) were mixed with stirring, and diluted with butyl acetate so that the solid content concentration in the mixed coating liquid was 1% by mass. A coating solution H was obtained.

(Preparation of coating liquid I for low refractive index layer)
DPHA 3.3 parts by mass Hollow silica (18.2%) 40.0 parts by mass RMS-033 0.7 parts by mass Irgacure 907 0.2 parts by mass Sol liquid a 6.2 parts by mass MEK 159.6 parts by mass

(Preparation of coating liquid J for low refractive index layer)
DPHA 3.3 parts by mass Hollow silica (18.2%) 40.0 parts by mass RMS-033 0.7 parts by mass Irgacure 907 0.2 parts by mass Sol solution a 6.2 parts by mass MEK 134.1 parts by mass Cyclohexanone 165 .5 parts by mass

  The solution was stirred and then filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating solution for a low refractive index layer.

The compounds used (for which detailed descriptions are omitted in the text) are shown below.
PET-30: A mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (manufactured by Nippon Kayaku Co., Ltd.)
Irgacure 184: Polymerization initiator (Ciba Specialty Chemicals Co., Ltd.)
SX-350: Cross-linked polystyrene particles having an average particle size of 3.5 μm (refractive index: 1.60, manufactured by Soken Chemical Co., Ltd., 30% toluene dispersion. Used after dispersion at 10,000 rpm for 20 minutes in a Polytron disperser)
Cross-linked acrylic-styrene particles: average particle size 3.5 μm (refractive index 1.55, manufactured by Soken Chemical Co., Ltd., 30% toluene dispersion)
FP-132: Fluorine surface modifier

KBM-5103: Silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.).
JN7228A: Thermally crosslinkable fluorine-containing polymer (refractive index 1.42, solid content concentration 6%, manufactured by JSR Corporation) “OPSTAR JN-7228A: trade name”
JTA113: Thermally crosslinkable fluorine-containing polymer (refractive index: 1.44, solid content concentration: 6%, manufactured by JSR Corporation) “OPSTAR JTA-113: trade name”
P-1: Perfluoroolefin copolymer (1)
DPHA: Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd.)
MEK-ST-L: Silica sol (silica, MEK-ST particle size difference, average particle size 45 nm, solid content concentration 30%, manufactured by Nissan Chemical Co., Ltd.)
Hollow silica: KBM-5103 surface-modified hollow silica sol (CS-60; trade name, Catalyst Chemical Industry Co., Ltd., refractive index 1.31, average particle size 60 nm, shell thickness 10 nm, porosity 58%, solid content concentration 20% KBM-5103 surface modified to give a surface modification rate of 30% by mass of silica (solid content concentration 18.2%)
KF96-1000CS: straight silicone (manufactured by Shin-Etsu Chemical Co., Ltd.)
X22-164C: Reactive silicone (manufactured by Shin-Etsu Chemical Co., Ltd.)
RMS-033: Reactive silicone (manufactured by Gelest Co., Ltd.)
R-2020: Fluoroalkyl acrylate monomer (Daikin Co., Ltd.)
R-3833: Fluoroalkyl acrylate monomer (manufactured by Daikin Corporation)
FMS-121: Fluoroalkyl silicone (manufactured by Gelest Co., Ltd.)
Irgacure 907: Photopolymerization initiator (manufactured by Ciba Specialty Chemicals)

[Example 1]
(1-1) Coating of hard coat layer A and hard coat layer C As a support, a triacetyl cellulose film (TD80U, manufactured by Fuji Photo Film Co., Ltd.) is unrolled in a roll form and used directly for the hard coat layer. Using a microgravure roll with a diameter of 50 mm and a doctor blade having a gravure pattern with a line number of 180 lines / inch and a depth of 40 μm and a doctor blade, the coating liquid was applied at a conveyance speed of 30 m / min, dried at 60 ° C. for 150 seconds, Further, using a 160 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) under a nitrogen purge such that the oxygen concentration is 1.0 vol% or less, the illumination intensity is 400 mW / cm ² and the hard coat layer A is irradiated. the amount 250 mJ / cm ^2, the hard coat layer C to cure the coating layer by ultraviolet irradiation dose 300 mJ / cm ^2, hard To form a coating layer, it was wound up. After curing, the rotation speed of the gravure roll was adjusted so that the hard coat layer A had a thickness of 6 μm and the hard coat layer C had a thickness of 8 μm.

(1-2) Coating of hard coat layer B A triacetyl cellulose film (TD80U, manufactured by Fuji Photo Film Co., Ltd.) is unwound as a support in the form of a roll, and the above-mentioned coating liquid for hard coat layer is directly applied to the number of lines. Using a microgravure roll with a diameter of 50 mm having a gravure pattern of 135 lines / inch and a depth of 60 μm, and a doctor blade, the coating was performed at a conveyance speed of 10 m / min, dried at 60 ° C. for 150 seconds, and then an oxygen concentration of 1 Using a 160 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) under a nitrogen purge of 0.0 vol% or less, irradiating ultraviolet rays with an illuminance of 400 mW / cm ² and an irradiation amount of 250 mJ / cm ² The coating layer was cured to form a hard coat layer and wound up. After curing, the gravure roll rotation speed was adjusted so that the thickness of the hard coat layer was 3.6 μm.

(2) Coating of medium refractive index layer A A triacetyl cellulose film (TD80UF, manufactured by Fuji Photo Film Co., Ltd.) coated up to the hard coat layer is unwound again, and the coating liquid for the medium refractive index layer has a line number of 180. Coating was performed using a micro gravure roll having a diameter of 50 mm and a gravure pattern having a thickness of 40 μm per inch and a doctor blade. Drying conditions were 90 ° C. and 30 seconds, and UV curing conditions were as follows: a 180 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) while purging with nitrogen so that the oxygen concentration was 1.0 vol% or less. The irradiance was 400 mW / cm ² and the irradiation amount was 400 mJ / cm ² . The medium refractive index layer was formed and wound up while adjusting the rotation speed of the gravure roll so that the thickness after application was 67 nm. The medium refractive index layer after curing had a refractive index of 1.630.

(3) Coating of the high refractive index layer A The triacetyl cellulose film (TD80UF, manufactured by Fuji Photo Film Co., Ltd.) coated up to the middle refractive index layer is unwound again, and the coating liquid for the high refractive index layer is added to the number of lines. Coating was performed using a micro gravure roll having a diameter of 50 mm and a gravure pattern of 180 lines / inch and a depth of 40 μm and a doctor blade. Drying conditions were 90 ° C. and 30 seconds, and ultraviolet curing conditions were 240 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) while purging with nitrogen so that the atmosphere had an oxygen concentration of 1.0 volume% or less. The irradiance was 600 mW / cm ² and the irradiation amount was 400 mJ / cm ² . A high refractive index layer was formed and wound up while adjusting the rotation speed of the gravure roll so that the thickness after coating was 107 nm. The high refractive index layer after curing had a refractive index of 1.905.

(4-1) Coating of low refractive index layer “Coating curing method A”
The triacetyl cellulose film coated up to the hard coat layer or the high refractive index layer is unwound again, and the above-mentioned coating solution for the low refractive index layer is a microgravure having a diameter of 180 lines / inch and a gravure pattern with a depth of 40 μm and a diameter of 50 mm. Using a roll and a doctor blade, it was applied at a transfer speed of 15 m / min, pre-dried at 120 ° C. for 150 seconds, and further post-dried at 140 ° C. for 8 minutes, and the oxygen concentration was 0.1% by volume. Using a 240 W / cm air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) under a nitrogen purge such as the following, an ultraviolet ray with an illuminance of 400 mW / cm ² and an irradiation amount of 900 mJ / cm ² is irradiated to a thickness of 100 nm. A low refractive index layer was formed and wound up while adjusting the rotation speed of the gravure roll.

(4-2) Coating of low refractive index layer “Coating curing method B”
The procedure was the same as “Coating and curing method A” except that post-drying was omitted.

(4-3) Coating of low refractive index layer “Coating and curing method C”
The coating solution for the low refractive index layer prepared above was applied using a wire bar so that the thickness after curing was about 100 nm, and heat-cured at 90 ° C. for 1 hour to form an antireflection layer.

(4-4) Coating of low refractive index layer “Coating curing method D”
(Die coater configuration)
The slot die 13 has an upstream lip land length I _UP of 0.5 mm, a downstream lip land length I _LO of 50 μm, a length of the opening of the slot 16 in the web running direction of 150 μm, and a length of the slot 16 of 50 mm. I used one. The gap between the upstream lip land 18a and the web W is 50 μm longer than the gap between the downstream lip land 18b and the web W (hereinafter referred to as an overbite length of 50 μm), and the gap between the downstream lip land 18b and the web W _GL was set to 50 μm. Further, the gap G _B between the gap G _S, and the back plate 40a and the web W between the side plate 40b and the web W in the vacuum chamber 40 were both 200 [mu] m.
The triacetyl cellulose film coated up to the hard coat layer was unwound again, and the above coating solution for low refractive index layer was applied at a coating speed of 25 m / min by the die coating method. After drying at 120 ° C. for 150 seconds and further drying at 140 ° C. for 8 minutes, a 240 W / cm air-cooled metal halide lamp (I-Graphics Co., Ltd.) under a nitrogen purge that results in an oxygen concentration of 0.1% by volume or less. The low refractive index layer having a thickness of 100 nm was formed and wound by irradiating with ultraviolet rays having an illuminance of 400 mW / cm ² and an irradiation amount of 900 mJ / cm ² .

(4-5) Coating of low refractive index layer “Coating curing methods E, F, G, H”
Except that the downstream lip land length I _L0 was set to E = 10 μm, F = 30 μm, G = 100 μm, and H = 120 μm, respectively, by the above-mentioned die coater coating, the same as “Coating curing method D”.

(4-6) Coating of low refractive index layer “Coating curing methods I, J, K, L”
Except that the overcoat length L0 of the die coater was set to I = 0 μm, J = 30 μm, K = 120 μm, and L = 150 μm in the above-described die coater application, the same as “Coating and curing method D”.

(Preparation of antireflection film sample)
As shown in Tables 1 to 4, antireflection film samples were prepared by the above method.

(Saponification treatment of antireflection film)
After the film formation, the following processing was performed on the samples except for the samples 101 and 102.
A 1.5 mol / l sodium hydroxide aqueous solution was prepared and kept at 55 ° C. A 0.01 mol / l dilute sulfuric acid aqueous solution was prepared and kept at 35 ° C. The prepared antireflection film was immersed in the aqueous sodium hydroxide solution for 2 minutes, and then immersed in water to sufficiently wash away the aqueous sodium hydroxide solution. Subsequently, after being immersed in the above-mentioned dilute sulfuric acid aqueous solution for 1 minute, it was immersed in water to sufficiently wash away the dilute sulfuric acid aqueous solution. Finally, the sample was thoroughly dried at 120 ° C.

(Evaluation of antireflection film)
The following items were evaluated for the film samples obtained after the saponification treatment. However, for the samples 101 and 102, the following items were similarly evaluated for the film samples not subjected to the saponification treatment.
(1) Average reflectance Using a spectrophotometer (manufactured by JASCO Corporation), the spectral reflectance at an incident angle of 5 ° was measured in a wavelength region of 380 to 780 nm. The average reflectance of 450-650 nm was used for the result.
(2) Steel wool scratch resistance evaluation A rubbing test was performed under the following conditions using a rubbing tester.
Evaluation environmental conditions: 25 ° C., 60% RH
Rub material: Steel wool (manufactured by Nippon Steel Wool Co., Ltd., Gelade No. 0000) was wound around the rubbing tip (1 cm × 1 cm) of a tester that was in contact with the sample, and the band was fixed so as not to move.
Moving distance (one way): 13 cm, rubbing speed: 13 cm / sec, load: 500 g / cm ² , tip contact area: 1 cm × 1 cm, rubbing frequency: 10 reciprocations.
An oil-based black ink was applied to the back side of the rubbed sample and visually observed with reflected light, and scratches on the rubbed portion were evaluated according to the following criteria.
A: Even when viewed very carefully, no scratches are visible.
○: Slightly weak scratches are visible when viewed very carefully.
○ △: Weak scratches are visible.
Δ: Moderate scratches are visible.
Δ × ˜ ×: There is a scratch that can be seen at first glance.

(3) Adhesion evaluation The surface of the antireflective film having the low refractive index layer was cut with a cutter knife into a grid pattern with 11 vertical and 11 horizontal cuts, and a total of 100 square grids were carved. A polyester adhesive tape (NO. 31B) manufactured by Denko Co., Ltd. was pressure-bonded, and the adhesion test was repeated three times at the same place. The presence or absence of peeling was visually observed, and the following four-stage evaluation was performed.
◎: No peeling was observed in 100 squares ○: No peeling was observed in 100 squares within 2 squares △: peeling was observed in 100 squares 3 to 10 mm ×: The one in which peeling was observed in 100 cells exceeded 10 mm

(4) Eraser rubbing resistance An antireflection film is fixed on a glass surface with an adhesive, and an anti-reflection film MONO (trade name, manufactured by Dragonfly), which is hollowed to a diameter of 8 mm and a thickness of 4 mm, is used as a head of a rubbing tester. After pressing vertically from above with a load of 500 g / cm ^{2 on} the surface, rubbing 200 times at a stroke length of 3.5 cm and a rubbing speed of 1.8 cm / s under conditions of 25 ° C. and 60 RH%, the attached eraser After removal, the rubbing part of the sample was visually confirmed, and the degree of scratching on the surface was evaluated three times on average by repeating the above test three times.
○: Scratches are hardly recognized.
Δ: Slight scratches are observed.
X: Scratches are clearly recognized.
XX: Scratches are recognized on the entire surface after rubbing.

(5) Magic wiping property The anti-reflection film is fixed on the glass surface with an adhesive, and the diameter of the black magic “Mackey Extra Fine (trade name: made by ZEBRA)” pen tip (thin) under the condition of 25 ° C. and 60 RH%. Write a 5-mm circle three times, and wipe it back and forth 20 times with a load that causes the bundle of Bencot to be dented with Bencot (trade name, Asahi Kasei Co., Ltd.) which is folded into 10 sheets after 5 seconds. The writing and wiping were repeated under the above conditions until after the magic did not disappear by wiping, and the number of times of wiping was determined. The above test was repeated 4 times, and the following 4 grades were evaluated on average.
○: Can be wiped 10 times or more.
Δ: Can be wiped off several times to less than 10 times.
×: Can be wiped off only once.
××: Cannot be wiped once

(6) Silicone (Si atoms), surface segregation ratio evaluation Shimadzu Corp. ESCA-3400 each measurement for the antireflection film in the (vacuum 1 × 10- ⁵ Pa, X-ray source of fluoroalkyl (F atom) Intensity ratio Si2p / C1s (= Si (a)), F1s / C1s (= F (a)) and ESCA- of target surface Mg, voltage 12 kV, current 20 mA) The photoelectron spectrum measured from the surface of the low-refractive index layer cut to 1/5 (± 5%) with an ion etching apparatus (ion gun, voltage 2 kV, current 20 mA) attached to 3400 from the surface 80% below. From the intensity ratios Si2p / C1s (= Si (b)) and F1s / C1s (= F (b)), changes in the respective intensity ratios before and after etching, Si (a / Si (b), F (a) / F (b), and changes of the respective Si2p / C1s ratio and F1s / C1s ratio before and after etching (intensity ratio of photoelectron spectrum at the top of the low refractive index layer / low) The change in the intensity ratio of the photoelectron spectrum in the vicinity of the lower layer 80% deep from the surface of the refractive index layer was evaluated in the following three stages. The above measurement was performed at three locations at least 2 cm apart from each other on the same film surface.
A: The strength ratio after etching is 5 times or more and 1 or more places.
○: The strength ratio after etching is less than 5 times, and 3 times or more is 1 place or more.
Δ: The strength ratio after etching is less than 3 times, and 1.5 times or more is one or more places.
-: Intensity ratio after etching is less than 1.5 times or F1s and C1s are obtained at the peak positions of respective photoelectron spectra, and Si2p is derived from silicone (Si atom of polydimethylsiloxane) having a binding energy of around 105 eV. The intensity at the peak position was used for the above-described intensity ratio calculation to distinguish it from Si atoms derived from inorganic silica particles. Preliminary experiments in which the surface of the low-refractive index layer is gradually scraped under various etching conditions are performed, and the depth of 80% from the surface is reached from the etching conditions required to reach the lower hard coat layer or high-refractive index layer. Measured after obtaining.

In Samples 005, 006, 008, and 009 described in Tables 1 and 5 above, “present invention” should be read as “reference examples”. Samples 103 to 109, 204, and 208 containing a fluorine-containing binder described in Tables 2 , 3 , 6, and 7 described above should be read as “reference examples”. Further, in the sample 102 described in Tables 2 and 6 , “present invention” is read as “reference example”.
From the results shown in Tables 4 to 7, the following is clear.
The antireflection film of the present invention satisfies the balance of reflectance, scratch resistance, magic wiping property, and adhesion in a well-balanced manner, and as a antireflection film, the performance is improved as a whole. The samples of the present invention can achieve low reflection with respect to the comparative sample 001, and the samples 003, 008, 011 and the like obtained by adding silicone or a fluoroalkyl compound to the sample 002 have improved magic wiping properties. Furthermore, samples 103 and 106 using silicone and fluorine in combination exhibited a higher magic wiping property.
Further, from the results of Table 4, although the samples 301 to 312 were able to be applied, a sample in which streaky unevenness occurred in the longitudinal direction of the base was confirmed from the visual surface evaluation result by black coating, and the present invention. The significance of the coating production conditions was shown.

[Example 2]
Next, this invention sample film of Example 1 was bonded together with the polarizing plate, and the polarizing plate with reflection prevention was produced. When a liquid crystal display device having an antireflection layer disposed on the outermost layer using this polarizing plate was produced, there was little reflection of external light, and the reflected image was not noticeable and had excellent visibility. In addition, the antifouling property, dustiness, and film strength, which are problems in the actual usage form, were all satisfied.

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

[Example 4]
A viewing angle widening film as a protective film on the liquid crystal cell side of the polarizing plate on the viewing side of the transmission type TN liquid crystal cell to which the sample of the present invention of Example 1 is attached, and a protective film on the liquid crystal cell side of the polarizing plate on the backlight side (Wide-view film SA 12B, manufactured by Fuji Photo Film Co., Ltd.), a liquid crystal with excellent contrast in a bright room, very wide viewing angles in the vertical and horizontal directions, extremely excellent visibility, and high display quality. A display device was obtained.

[Example 5]
When the sample of the present invention of Example 1 was bonded to the glass plate on the surface of the organic EL display device via an adhesive, reflection on the glass surface was suppressed, visibility was high, and contamination against fingerprints and dust was prevented. In this way, a display device that can sufficiently withstand was obtained.

[Example 6]
Using the sample of the present invention of Example 1, a polarizing plate with a single-sided antireflection film was prepared, and a λ / 4 plate was laminated on the opposite side of the polarizing plate on the side having the antireflection film, with the antireflection film side being the outermost side. When attached to the glass plate on the surface of the organic EL display device so as to be on the surface, the surface reflection and the reflection from the inside of the surface glass were cut, and a display with extremely high visibility was obtained.

It is a schematic sectional drawing which shows typically an example of the antireflection film of this invention. It is a schematic sectional drawing which shows the structural example of the apparatus which performs application | coating of each layer continuously. It is a schematic sectional drawing which shows the coater using a slot die. (A) is a schematic sectional drawing which shows the slot die of this invention, (B) is a schematic sectional drawing which shows the conventional slot die. It is a perspective view which shows the slot die of an application | coating process, and its periphery. It is a schematic sectional drawing which shows the pressure reduction chamber and web which adjoin. It is a schematic sectional drawing which shows the pressure reduction chamber and web which adjoin.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Antireflection film 2 Transparent support 3 Conductive layer 4 Hard coat layer 5 Medium refractive index layer 6 High refractive index layer 7 Low refractive index layer 8 Matte particle 10 Coater 11 Backup roll 13 Slot die 14 Coating liquid 14a Bead 14b Coating film 15 Pocket 16 Slot 16a Opening 17 Tip Lip 18 Flat 18a Upstream Lip Land 18b Downstream Lip Land 30 Conventional Slot Die 31a Upstream Lip Land 31b Downstream Lip Land 32 Pocket 33 Slot 40 Decompression Chamber 40a Back Plate 40b Side Plate 40c Screw 110 Step of continuously feeding roll-shaped support film 120 Step of winding support film 100, 200, 300, 400 Film-forming units 101, 201, 301, 401 Applying coating solution Curing the steps 103,203,303,403 coating to dry to step 102, 202, 302, and 402 coating

Claims (9)

A polymer binder having a saturated hydrocarbon chain or polyether chain substantially free of fluorine as a main chain in a low refractive index layer located farthest from the transparent support, hollow silica particles, and a compound for reducing surface free energy; The hollow silica particles have a porosity x of 10 to 60% represented by the formula (I) when the radius of the cavity in the particle is a and the radius of the outer shell of the particle is b, The compound for reducing the surface free energy is a silicone compound having a (meth) acryloyl group at the end and / or side chain of a compound chain containing a plurality of dimethylsilyloxy units as repeating units, and reduces the surface free energy. An antireflection film comprising a compound in a range of 0.01 to 20% by mass of the total solid content of the low refractive index layer.
Formula (I): x = (4πa 3/3) / (4πb 3/3) × 100 The antireflection film according to claim 1, wherein the hollow silica particles are treated with a silane coupling agent having an acryloyl group or a methacryloyl group. Silicone emission is segregated on the surface of the low refractive index layer, it photoelectron spectral intensity ratio Si / C in 80% lower from the outermost surface and the outermost surface of the low refractive index layer is greater 80% 5 times more than the lower layer in the outermost surface The antireflection film according to claim 1 or 2. The antireflection film according to any one of claims 1 to 3, the surface free energy is equal to or less than 25 mN / m. The following general formula (A) is produced in the presence of an acid catalyst and / or a metal chelate compound in at least one of the low refractive index layer farthest from the transparent support and the lower layer of the low refractive index layer. The antireflection film according to any one of claims 1 to 4 , comprising at least one of a hydrolyzate of an organosilane and a partial condensate thereof.
General formula (A): (R ¹⁰ ) _m Si (X) _4-m
(In the formula, R ¹⁰ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. X represents a hydroxyl group or a hydrolyzable group. M represents an integer of 1 to 3.) In the manufacturing method of the anti-reflective film in any one of Claims 1-5 ,
The land of the tip lip of the slot die is brought close to the surface of the transparent support that is continuously supported by the backup roll, and from the slot of the tip lip, a saturated hydrocarbon chain or polyether chain substantially free of fluorine. And a void having a porosity x represented by the formula (I) where the radius of the cavity in the particle is a and the radius of the outer shell of the particle is b Application of a coating solution containing silica particles and a compound that reduces the surface free energy, which is a silicone compound having a (meth) acryloyl group at the end and / or side chain of a compound chain containing a plurality of dimethylsilyloxy units as repeating units. The land length in the web traveling direction of the tip lip on the transparent support traveling direction side of the slot die is 30 μm or less. When a slot die having a size of 100 μm or less is used and the slot die is set at a coating position, a gap between the tip lip and the web on the opposite side to the moving direction of the web is set to the tip lip and the web on the web moving direction side. At least one low refractive index layer located farthest from the transparent support, with a dry film thickness of 200 nm or less, using a coating apparatus installed to be 30 μm or more and 120 μm or less larger than the gap between A method for producing an antireflection film. The viscosity at the time of application of the coating liquid is 2.0 [mPa · sec] or less, and the amount of the coating liquid applied to the transparent support is 2.0 to 5.0 [ml / m ² ]. The manufacturing method of the antireflection film of Claim 6 . A polarizing plate comprising the antireflection film according to any one of claims 1 to 5 or the antireflection film obtained by the method for producing an antireflection film according to claim 6 or 7 . A liquid crystal display comprising the antireflection film according to any one of claims 1 to 5, the antireflection film obtained by the method for producing an antireflection film according to claim 6 or 7 , or the polarizing plate according to claim 8. apparatus.

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