JP6225428B2 - Resin composition for low refractive index layer and antireflection film - Google Patents

Description

  The present invention is capable of forming a resin composition for forming a low refractive index layer, which is one of the constituent layers of an antireflection film applied to the touch panel surface and the like, particularly a low refractive index layer having excellent fingerprint wiping properties. The present invention relates to an antireflective film comprising a resin composition and a low refractive index layer made of the resin composition.

  Currently, touch panels are widely used as devices that can input information by directly touching an image display unit. An antireflection film is generally attached to the surface of the touch panel in order to reduce the deterioration of visibility due to reflected light from outside light. However, since the touch panel comes into contact with the outside air or touches human hands almost on a daily basis, there are problems such as dirt and fingerprints adhering to the surface of the antireflection film, deteriorating visibility and detracting from aesthetics. It was.

  In order to solve this problem, Patent Document 1 and Patent Document 2 have proposed antireflection films having antifouling properties. The antireflection film is generally configured by combining a high refractive index layer having a relatively high refractive index and a low refractive index layer having a relatively low refractive index. Antifouling property is imparted to the low refractive index layer constituting the outermost surface layer of the prevention film. Specifically, in Patent Document 1, antifouling is imparted by adding a silicone material having a polydimethylsiloxane structure to the low refractive index layer. In Patent Document 2, antifouling is imparted by adding a fluorosurfactant to the low refractive index layer.

JP 2011-154177 A JP 2008-122603 A

  However, the antireflection film of Patent Document 1 is excellent in antifouling performance against magic ink and the like, but has a problem of insufficient fingerprint adhesion and wiping. In addition, the antireflection film of Patent Document 2 has a problem in that the amount of fluorine-containing component is inappropriate, resulting in insufficient fingerprint adhesion and wiping properties, and lack of antifouling performance such as magic ink.

  Accordingly, an object of the present invention is to provide a resin composition for a low refractive index layer capable of forming a low refractive index layer excellent in fingerprint wiping properties, and an antireflection film using the same.

For this purpose, the present invention adopts the following means.
(1) (a) Fluorine-containing UV-curable resin (so-called fluorine-containing UV-curable compound) 5 to 15% by mass, (b) Polyether-modified polydimethylsiloxane having an acrylic group or Polyester-modified polydimethylsiloxane having an acrylic group 2 to 8% by mass, (c ) 9 to 70% by mass of ultraviolet curable resin (so-called ultraviolet curable resin compound) copolymerizable with component (a) and component (b), (d) hollow silica fine particles 22 to 83% by mass, (e) 1 to 10% by mass of a photopolymerization initiator (however, the total of the components (a) to (e) is 100% by mass), and the content of the component (b) is A resin composition for a low refractive index layer in an antireflection film, characterized by being 1.0% by mass or more less than the content of the component (a).
(2) An antireflection film comprising a low refractive index layer obtained by curing the resin composition for a low refractive index layer according to (1) as an outermost layer.
(3) The antireflection film according to (2), wherein the low refractive index layer has a refractive index of 1.38 to 1.45.

  In the present invention, “OO to XX” indicating a numerical range means that the numerical values of the lower limit (OO) and the upper limit (XX) are included. Therefore, if it is expressed accurately, it will be “XX or more and XX or less”.

According to the present invention, the composition of the resin composition for the low refractive index layer (particularly, (a) a fluorine-containing ultraviolet curable compound directly related to fingerprint wiping properties and (b) a polyether-modified polydimethyl having an acrylic group. A resin composition capable of forming a low refractive index layer excellent in fingerprint wiping property by appropriately setting a blending balance of a polyester-modified polydimethylsiloxane having a siloxane or acrylic group, and an antireflection film using the resin composition Can be provided.

<Resin composition>
The resin composition of the present invention is a resin composition for forming a low refractive index layer which is one of the layers constituting an antireflection film adhered to the surface of a touch panel or the like, and includes (a) fluorine-containing UV-curable compound , (b) polyether-modified polydimethylsiloxane having acrylic group or polyester-modified polydimethylsiloxane having acrylic group, and (c) UV-curable copolymerizable with component (a) and component (b) Type resin compound , (d) hollow silica fine particles, and (e) a photopolymerization initiator.

<(A) Fluorine-containing UV curable resin (so-called fluorine-containing UV curable compound) >
Fluorine-containing UV-curable resin (so-called fluorine-containing UV-curable compound) is for developing antifouling function, and adheres to fingerprints, which are lipids that adhere when the surface of the low refractive index layer is touched. Can be weakened and the fingerprint wiping property can be improved. Examples of the fluorine-containing ultraviolet curable resin (so-called fluorine-containing ultraviolet curable compound) include (meth) acrylates containing C2 to C7 perfluoroalkyl chains. Specifically, an OPTOOL manufactured by Daikin Industries, Ltd. DAC-HP, MegaFac RS-75 manufactured by DIC Corporation and the like can be mentioned. In the present specification, “(meth) acrylate” means acrylate and methacrylate. Similarly, “(meth) acrylic monomer” described later refers to an acrylic monomer and a methacrylic monomer, and “(meth) acryloyl group” refers to an acryloyl group and a methacryloyl group.

The fluorine-containing ultraviolet curable resin (so-called fluorine-containing ultraviolet curable compound) is contained in the low refractive index layer resin composition in an amount of 5 to 15% by mass. If the content is less than 5% by mass, the adhesion of fingerprints that adhere when the surface of the low refractive index layer is touched cannot be weakened. On the other hand, if it exceeds 15% by mass, the fingerprint wiping property deteriorates.

<(B) Polyether-modified polydimethylsiloxane having an acrylic group or polyester-modified polydimethylsiloxane having an acrylic group>
The polyether-modified polydimethylsiloxane having an acrylic group or the polyester-modified polydimethylsiloxane having an acrylic group can improve the wiping property of fingerprints attached to the surface of the low refractive index layer. Specific examples of the polyether-modified polydimethylsiloxane having an acrylic group or the polyester-modified polydimethylsiloxane having an acrylic group include BYK-UV3500, BYK-UV3530, BYK-UV3570, etc., manufactured by Big Chemie Japan. It is done.

  The polyether-modified polydimethylsiloxane having an acrylic group or the polyester-modified polydimethylsiloxane having an acrylic group is contained in the resin composition for a low refractive index layer in an amount of 2 to 8% by mass. When the content is less than 2% by mass, the wiping property of the fingerprint attached to the surface of the low refractive index layer is not improved. On the other hand, if it exceeds 8% by mass, it is not possible to weaken the adhesion of fingerprints that adhere when the surface of the low refractive index layer is touched.

<(C) UV curable resin (so-called UV curable resin compound) >
The ultraviolet curable resin (so-called ultraviolet curable compound) copolymerizable with the component (a) and the component (b) can impart hardness to the low refractive index layer. Examples of the ultraviolet curable resin (so-called ultraviolet curable compound) copolymerizable with the component (a) and the component (b) include monofunctional (meth) acrylate and polyfunctional (meth) acrylate. Specifically as monofunctional (meth) acrylate, (meth) acrylic acid alkyl ester, (meth) acrylic acid (poly) ethylene glycol group-containing (meth) acrylic acid ester and the like are preferable. Examples of the polyfunctional (meth) acrylate include ester compounds of polyhydric alcohol and (meth) acrylic acid, polyfunctional polymerizable compounds containing two or more (meth) acryloyl groups such as urethane-modified acrylate, and the like.

The UV curable resin compound copolymerizable with the component (a) and the component (b) is contained in the low refractive index layer resin composition in an amount of 9 to 70% by mass. If the content is less than 9% by mass, the low refractive index layer is insufficient in hardness and the transmittance is lowered. On the other hand, when it exceeds 70 mass%, the fingerprint wiping property is not improved.

<(D) Hollow silica fine particles>
The hollow silica fine particles are blended to actively lower the refractive index of the low refractive index layer. The refractive index of the hollow silica fine particles varies depending on the production method, but is preferably about 1.25 to 1.40. The hollow silica fine particles are not particularly limited as long as the refractive index is lowered, and known hollow silica fine particles that have been conventionally used for the low refractive index layer constituting the antireflection film can be used. Specific examples include through rear NAU, which are acrylic modified hollow silica fine particles manufactured by JGC Catalysts & Chemicals. Moreover, the average particle diameter of the hollow silica fine particles should just be the same as the past. Specifically, it is about 10 to 100 nm.

  The hollow silica fine particles are contained in an amount of 22 to 83% by mass in the composition for a low refractive index layer. When the content of the hollow silica fine particles is less than 22% by mass, the refractive index of the low refractive index layer cannot be in the range described below. On the other hand, when the content of the hollow silica fine particles is more than 83% by mass, the coating film strength becomes weak, which is not preferable.

<(E) Photopolymerization initiator>
The photopolymerization initiator is used as a polymerization initiator when a coating film is formed by curing the coating solution for the low refractive index layer with active energy rays such as ultraviolet rays (UV). The photopolymerization initiator is not particularly limited as long as it initiates polymerization upon irradiation with active energy rays, and known compounds can be used. For example, acetophenone-based polymerization initiators such as 1-hydroxycyclohexyl phenyl ketone and 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzoin, 2,2-dimethoxy 1,2-diphenylethane-1 Benzoin-based polymerization initiators such as -one, benzophenone, [4- (methylphenylthio) phenyl] phenylmethanone, 4-hydroxybenzophenone, 4-phenylbenzophenone, 3,3 ', 4,4'-tetra (t- Examples thereof include benzophenone polymerization initiators such as (butylperoxycarbonyl) benzophenone, and thioxanthone polymerization initiators such as 2-chlorothioxanthone and 2,4-diethylthioxanthone.

  1-10 mass% of photoinitiators are contained in the resin composition for low refractive index layers. When the content of the photopolymerization initiator is less than 1% by mass, the low refractive index layer is not sufficiently cured. On the other hand, if the content of the photopolymerization initiator exceeds 10% by mass, the photopolymerization initiator is unnecessarily increased, which is not preferable.

<Antireflection film>
The antireflection film has a configuration in which at least an antireflection layer is laminated on one surface of the transparent substrate film. The antireflection layer can be constituted only by the low refractive index layer formed by the resin composition for the low refractive index layer, but is configured in combination with a high refractive index layer having a higher refractive index than the low refractive index layer. It is preferable. In the case of comprising only the low refractive index layer, the antireflection effect can be secured by itself, but when the low refractive index layer and the high refractive index layer are combined, the low refractive index layer and the high refractive index layer Due to the significant difference in refractive index, a higher antireflection effect can be obtained.

<Transparent substrate film>
As the transparent substrate film, a film made of a polyester resin, a polycarbonate resin, a triacetyl cellulose resin, a norbornene resin, a cycloolefin resin, or the like can be used. The film made of polyester resin is made of PET film (Lumirror U-403) manufactured by Toray Industries, Inc. The film made of polycarbonate resin is made of polycarbonate film (PC-2151) made by Teijin Chemicals Limited, and triacetyl cellulose resin. The film is a triacetyl cellulose film (Fujitac) manufactured by Fuji Film Co., Ltd., the film made of norbornene resin is the Arton film manufactured by JSR Co., and the film made of cycloolefin resin is manufactured by Nippon Zeon Co., Ltd. Examples include ZEONOR films (ZF14, ZF16).

  The film thickness of the transparent substrate film is usually about 25 to 400 μm, preferably about 25 to 200 μm.

<Low refractive index layer>
The low refractive index layer is required to be set lower than the refractive index of the high refractive index layer, and when the hard coat layer is also laminated as necessary as described later, the refractive index is set lower than the hard coat layer. . Specifically, the refractive index of the low refractive index layer is preferably about 1.33 to 1.46. When the refractive index is less than 1.33, it is difficult to obtain sufficient hardness. On the other hand, when the refractive index exceeds 1.46, it is difficult to obtain sufficient antireflection performance.

<Resin composition for low refractive index layer>
The above-mentioned composition is used as the resin composition for forming the low refractive index layer. The low refractive index layer formed by using this has a refractive index in the above range while having sufficient hardness, and further has excellent antifouling properties, specifically fingerprint wiping properties. Therefore, the low refractive index layer is the outermost layer in the antireflection film. Thereby, it can be set as the antireflection film which has the outstanding fingerprint wiping property. On the other hand, if another layer is laminated on the surface layer side of the low refractive index layer, the fingerprint wiping property of the antireflection film is impaired.

<High refractive index layer>
The high refractive index layer is a layer for exhibiting an antireflection effect due to a significant refractive index difference from the low refractive index layer. The refractive index of the high refractive index layer is set higher than that of the low refractive index layer. When a hard coat layer is also laminated as necessary as described later, the refractive index is set higher than that of the hard coat layer. Specifically, the refractive index of the high refractive index layer is preferably about 1.6 to 2.4. When this refractive index is smaller than 1.6, the antireflection performance is impaired. On the other hand, it is difficult to form a high refractive index layer having a refractive index exceeding 2.4.

<Resin composition for high refractive index layer>
The resin composition for forming the high refractive index layer is not particularly limited as long as it is a known one that has been conventionally used for an antireflection film or the like in the range of the refractive index of the high refractive index layer. An organic material or an inorganic material dispersed and added to a binder as necessary to positively increase the refractive index can be used in the same manner as in the past.

  As the organic material, for example, a composition containing a polymerizable monomer having a refractive index after polymerization and curing of about 1.6 to 1.8 can be used. Examples of such a polymerizable monomer include 2-vinylnaphthalene, 4-bromostyrene, 9-vinylanthracene and the like. When these polymerizable monomers are used, a layer having a significantly high refractive index can be formed by itself, so that it is not always necessary to add an inorganic material. On the other hand, when an inorganic material is also used, a polymerizable monomer other than the above and a composition containing these polymers can be used as an active energy ray-curable resin during wet coating.

  Examples of the inorganic material include metal oxide fine particles such as zinc oxide, titanium oxide, cerium oxide, aluminum oxide, silane oxide, antimony oxide, zirconium oxide, tin oxide, and ITO. Among these, tin oxide, antimony oxide and ITO are preferable from the viewpoint of conductivity and antistatic ability, and titanium oxide, cerium oxide, zinc oxide and zirconium oxide are preferable from the viewpoint of high refractive index. The average particle diameter of the inorganic material fine particles preferably does not greatly exceed the thickness of the high refractive index layer, and is particularly preferably 0.15 μm or less. When the average particle diameter of the inorganic material fine particles is larger than the thickness of the high refractive index layer, the optical performance of the high refractive index layer tends to deteriorate, such as light scattering.

<Hard coat layer>
In addition, in order to improve the surface hardness of the antireflection film, a hard coat layer can be laminated on only one side or both sides of the transparent substrate film as necessary. When the antireflection layer is laminated on the laminated side, the antireflection layer is laminated on the inner layer side of the antireflection layer, that is, immediately above the transparent substrate film.

  The refractive index of the hard coat layer is preferably 1.49 to 1.70. If the refractive index is out of this range, the refractive index balance between the low refractive index layer and the high refractive index layer is lost, and interference fringes are generated. In addition, the thickness of the hard coat layer after drying and curing is preferably about 1 to 20 μm. A film thickness of less than 1 μm is not preferable because sufficient surface hardness cannot be obtained. A film thickness greater than 20 μm is not preferable because problems such as a decrease in flexibility occur.

<Resin composition for hard coat layer>
The resin composition for forming the hard coat layer is not particularly limited as long as it is a known resin composition conventionally used for antireflection films and the like. For example, a reactive silicon compound such as tetraethoxysilane or an active energy ray curable resin can be used, and these may be mixed. And the hard-coat layer can be formed by irradiating and hardening | curing active energy rays, such as an ultraviolet-ray and an electron beam, to the coating liquid for hard-coat layers prepared by adding a photoinitiator to these.

  Examples of the active energy ray-curable resin include monofunctional (meth) acrylate and polyfunctional (meth) acrylate. Specifically as monofunctional (meth) acrylate, (meth) acrylic acid alkyl ester, (meth) acrylic acid (poly) ethylene glycol group-containing (meth) acrylic acid ester and the like are preferable. Examples of the polyfunctional (meth) acrylate include ester compounds of polyhydric alcohol and (meth) acrylic acid, polyfunctional polymerizable compounds containing two or more (meth) acryloyl groups such as urethane-modified acrylate, and the like. Among these, from the viewpoint of achieving both productivity and hardness, a cured product of a composition containing an active energy ray-curable resin having a pencil hardness (evaluation method: JIS-K5600-5-4) of H or higher is preferable. .

  The photopolymerization initiator is used as a polymerization initiator when a coating film is formed by curing the hard coat layer coating liquid with an active energy ray such as ultraviolet (UV). The photopolymerization initiator is not particularly limited as long as it initiates polymerization upon irradiation with active energy rays, and known compounds can be used. For example, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1 -One, acetophenone polymerization initiators such as 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one, benzoin, 2,2-dimethoxy 1,2 -Benzoin polymerization initiators such as diphenylethane-1-one, benzophenone, [4- (methylphenylthio) phenyl] phenylmethanone, 4-hydroxybenzophenone, 4-phenylbenzophenone, 3,3 ', 4,4' -Benzophenone polymerization initiators such as tetra (t-butylperoxycarbonyl) benzophenone, 2-chlorothio Xanthone, such thioxanthone type polymerization initiators such as 2,4-diethyl thioxanthone, and the like.

  The hard coat layer may contain translucent fine particles. The light-transmitting fine particles form surface irregularities on the hard coat layer and improve antireflection properties (antiglare properties). The translucent fine particles are formed of, for example, a polymer obtained by polymerizing at least one monomer selected from vinyl chloride, (meth) acrylic monomer, styrene, and ethylene in addition to silica. . Furthermore, the hard coat layer may contain other additives such as a surface conditioner and a slip agent.

<Formation of low refractive index layer, high refractive index layer, hard coat layer>

  The low refractive index layer, the high refractive index layer, and the hard coat layer are formed by sequentially applying each resin composition onto the transparent substrate film, and then curing by irradiation with active energy rays. The coating method of the low refractive index layer, the high refractive index layer, and the hard coat layer is not particularly limited. For example, roll coating method, spin coating method, dip coating method, spray coating method, bar coating method, knife coating method, die coating method. Any known method such as an inkjet method or a gravure coating method can be employed. The type of active energy rays is not particularly limited, but it is preferable to use ultraviolet rays from the viewpoint of convenience and the like. In addition, in order to improve the adhesiveness of the hard coat layer to the transparent substrate film, it is possible to pre-treat the surface of the transparent substrate film such as a corona discharge treatment in advance.

  Further, from the viewpoint of coatability, each resin composition is preferably diluted with a solvent for coating. The solvent is not particularly limited as long as it is a known one that has been conventionally used for coating liquids for forming each layer. For example, alcohol-based, ketone-based, and ester-based solvents can be appropriately selected.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

((Resin composition for low refractive index layer; Example))
The following raw materials are used as the resin composition for the low refractive index layer, and each raw material has the composition described in Table 1 below, (a) a fluorine-containing ultraviolet curable compound, and (b) a polyether-modified poly having an acrylic group. Polyester-modified polydimethylsiloxane having dimethylsiloxane or acrylic group, (c) UV curable resin compound copolymerizable with (a) and (b), (d) hollow silica fine particles, and (e) photoinitiator And a resin composition for a low refractive index layer of Example 1-1 to Example 1-16 was prepared. In addition, in Table 1, the compounding amount of each material has described the mass% of solid content.

The raw materials for the resin composition for the low refractive index layer are as follows.
(A) Fluorine-containing ultraviolet curable compound :
OPTOOL DAC-HP manufactured by Daikin Industries, Ltd.
DIC Corporation Mega Fuck RS-75
(B) Modified polydimethylsiloxane:
A polyether-modified polydimethylsiloxane having an acrylic group;
BYK-UV3500 manufactured by Big Chemie Japan
BYK-UV3530 manufactured by Big Chemie Japan Co., Ltd.
Polyester-modified polydimethylsiloxane having acrylic groups;
BYK-UV3570 manufactured by Big Chemie Japan K.K.
(C) UV curable resin compound :
KAYARAD DPHA manufactured by Nippon Kayaku Co., Ltd.
Purple light UV-7600B manufactured by Nippon Synthetic Chemical Industry Co., Ltd.
(D) Hollow silica fine particles:
Acrylic-modified hollow silica fine particles manufactured by JGC Catalysts & Chemicals Co., Ltd.
Acrylic modified hollow silica fine particles manufactured by JGC Catalysts & Chemicals Co., Ltd.
(E) Photoinitiator:
IRGACURE907 (I-907) manufactured by Ciba Specialty Chemicals Co., Ltd.
IRGACURE 184 (I-184) manufactured by Ciba Specialty Chemicals Co., Ltd.

((Resin composition for low refractive index layer; comparative example))
As the resin composition for low refractive index, the following raw materials are also used in addition to the above raw materials, and the respective raw materials are mixed in the composition described in Table 2, and the low refractive index layer of Comparative Example 1-1 to Comparative Example 1-12 A resin composition was prepared. In Table 2, the blending amount of each material indicates mass% of solid content.

Each raw material is as follows. (A) Megafac F-558 manufactured by DIC Corporation was used as a resin that contains fluorine and does not cure ultraviolet rays with respect to the fluorine-containing ultraviolet curable polymerizable compound . (B) BYK331 manufactured by Big Chemie Japan Co., Ltd. was used as a polyether-modified polydimethylsiloxane that does not contain an acrylic group with respect to the modified polydimethylsiloxane having an acrylic group.

(Resin composition for high refractive index layer; HL)
(F) 47.5% by mass of metal oxide fine particles, (g) 47.5% by mass of an ultraviolet curable resin, and (h) 5% by mass of a photoinitiator are mixed as a resin composition for a high refractive index layer. A resin composition HL-1 for a high refractive index layer was prepared. In addition, the compounding quantity of each material has described the mass% of solid content.

The raw materials for the high refractive index layer resin composition are as follows.
(F) Metal oxide fine particles: RTTMIBK15WT% -N24 (titania dispersion) manufactured by CI Kasei Co., Ltd.
(G) UV curable resin: Purple light UV-7600B manufactured by Nippon Synthetic Chemical Industry Co., Ltd.
(H) Photoinitiator: IRGACURE184 (I-184) manufactured by Ciba Specialty Chemicals

(Resin composition for hard coat layer; HCL)
The following raw materials are used as the resin composition for hard coat, and each raw material has the composition described in Table 3 below. (I) Ultraviolet curable resin, (j) Translucent fine particles, (k) Surface adjustment An agent and (l) a photoinitiator were mixed to prepare hard coat resin compositions HCL1-1 to HCL1-4. In Table 3, the blending amount of each material indicates mass% of solid content.

The raw materials for the resin composition for hard coat are as follows.
(I) UV curable resin:
KAYARAD DPHA manufactured by Nippon Kayaku Co., Ltd.
Purple light UV-7600B manufactured by Nippon Synthetic Chemical Industry Co., Ltd.
(J) Light-transmitting fine particles: Sekisui Plastics Co., Ltd. styrene-acrylic copolymer organic fine particles SSX-105TND (average particle diameter 5.0 μm, refractive index 1.50)
(K) Surface conditioner: BYK-306 manufactured by Big Chemie Japan Co., Ltd.
(L) Photoinitiator: IRGACURE 184 (I-184) manufactured by Ciba Specialty Chemicals

((Antireflection film; Example 2-1))
As a transparent substrate film, a hard coat resin composition (HCL1-1) and a solvent (methyl isobutyl ketone) are 1: 1 on one surface of a PET film (product name: A4100, film thickness: 100 μm) manufactured by Toyobo Co., Ltd. The hard coat layer coating solution mixed at a ratio of 1 is applied with a bar coater so that the film thickness after curing is 7 μm, and the hard coat layer is cured by irradiating with a 120 W high-pressure mercury lamp by irradiating 400 mJ ultraviolet rays. Formed.

  Next, a coating solution for a high refractive index layer obtained by mixing a resin composition for high refractive index layer (HL-1) and a solvent (methyl isobutyl ketone) at a ratio of 1: 5 on the hard coat layer is obtained with a bar coater. A high refractive index layer was formed by applying the film after curing so as to have a thickness of 0.1 μm and irradiating it with 400 mJ of ultraviolet light using a 120 W high pressure mercury lamp in a nitrogen atmosphere.

  Finally, a coating solution for a low refractive index layer prepared by mixing a resin composition for a low refractive index layer (Example 1-1) and a solvent (methyl isobutyl ketone) at a ratio of 1: 5 on the high refractive index layer. An antireflection film (Example 2-1) was applied by a bar coater so that the film thickness after curing was 0.1 μm, and was cured by irradiation with 400 mJ of ultraviolet light in a 120 W high pressure mercury lamp in a nitrogen atmosphere. Was made.

((Antireflection film; Example 2-2 to Example 2-16))
Except that the resin composition for hard coat, the resin composition for high refractive index layer, and the resin composition for low refractive index layer were combined with the materials described in Table 4 below and the combination of each layer, the same as in Example 2-1. An antireflection film (Example 2-2 to Example 2-16) was prepared.

About each obtained antireflection film, fingerprint wiping property, scratch resistance, and minimum reflectance were measured by the following methods. The results are also shown in Table 4 below.
<Fingerprint wiping>
One drop of artificial finger oil (1 g of urea, 4.6 g of lactic acid, 8 g of sodium pyrophosphate, 7 g of sodium chloride, and 20 mL of ethanol diluted to 1 L with distilled water) is dropped on the surface of the antireflection film. Then, use Nippon Paper Crecia Co., Ltd. Kimwipe to blend in the artificial finger oil. Then, after carrying out 5 reciprocating wiping using Toray Co., Ltd. Toraysee, the surface trace was observed visually and evaluated in the following three steps.
○: When there is no trace of artificial finger oil △: When some trace of artificial finger oil remains *: When trace of artificial finger oil remains

<Abrasion resistance>
The surface of the antireflection film was subjected to a reciprocal friction of 10 strokes at a stroke width of 25 mm and a speed of 30 mm / sec by applying a load of 250 gf to # 0000 steel wool, and the surface was visually observed and evaluated by the following ○ and ×. Steel wool was gathered to about 10 mmφ, and was cut and rubbed so as to have a uniform surface.
○: 0 to 10 scratches ×: 11 or more scratches

<Minimum reflectivity>
In order to prevent back reflection of the antireflection film, the back surface is roughened with sandpaper and painted with black paint, and a spectrophotometer [trade name: U-best 560, manufactured by JASCO Corporation] is used. A 5 ° and −5 ° specular reflection spectrum at 780 nm was measured. The minimum reflectance (%) was read from the obtained reflection spectrum.

((Antireflection film; Comparative Example 2-1 to Comparative Example 2-12))
An antireflection film (Comparative Example 2-1 to Comparative Example 2-12) was produced in the same manner as in Example 2-1, except that the low refractive index layer resin composition was changed to the material described in Table 5. About the obtained antireflection film of each comparative example, fingerprint wiping property, scratch resistance, and minimum reflectance were measured in the same manner as in Examples. The results are also shown in Table 5 below.

  From the results of Table 4, in Examples 2-1 to 2-16, it was an antireflection film excellent in fingerprint wiping property, scratch resistance, and antireflection performance.

On the other hand, from the results of Table 5, Comparative Examples 2-1 to 2-9 are: (a) a fluorine-containing ultraviolet curable compound and (b) a polyether-modified polydimethylsiloxane having an acrylic group or a polyester having an acrylic group. Since the blending of the modified polydimethylsiloxane was not appropriate, the fingerprint wiping property was poor. In Comparative Example 2-10, since the blending amount of the photopolymerization initiator was small, the hardness (scratch resistance) was inferior. Since Comparative Example 2-11 was not a fluorine-containing ultraviolet curable compound but a resin containing fluorine and not ultraviolet-curing, the result was poor in scratch resistance. Since Comparative Example 2-12 was not a polyether-modified polydimethylsiloxane having an acrylic group or a polyester-modified polydimethylsiloxane having an acrylic group, but a polyether-modified polydimethylsiloxane not containing an acrylic group was used. Was a weak result.

Claims (3)

(A) 5 to 15% by mass of a fluorine-containing ultraviolet curable compound ,
(B) 2-8% by mass of a polyether-modified polydimethylsiloxane having an acrylic group or a polyester-modified polydimethylsiloxane having an acrylic group,
(C) 9 to 70% by mass of an ultraviolet curable resin compound copolymerizable with the component (a) and the component (b),
(D) 22 to 83% by mass of hollow silica fine particles,
(E) 1-10% by mass of a photopolymerization initiator,
(However, the total of the components (a) to (e) is 100% by mass),
The resin composition for a low refractive index layer in an antireflection film, wherein the content of the component (b) is 1.0% by mass or more less than the content of the component (a).   An antireflection film comprising a low refractive index layer obtained by curing the resin composition for a low refractive index layer according to claim 1 as an outermost layer. The antireflection film according to claim 2,
The antireflective film whose refractive index of the said low-refractive-index layer is 1.38-1.45.