JP2009242497A - Photosensitive resin composition, hard coat film using it, and reflection preventing film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition exhibiting sufficient antistatic characteristics, a high refractive index and transparency in formation of a cured film, and using no environmental load material to be suitably used for a hard coat layer or a high refractive index layer in an image display device such as a plasma display panel (PDP) and a liquid crystal display (LCD), and to provide a hard coat film using the above resin composition and a reflection preventing film. <P>SOLUTION: The photosensitive resin composition comprises a photocurable compound having at least three (meth)acryloyl groups, a photosensitive monomer having a polymerizable functional group and a polyether chain, a metal oxide, and a photopolymerization initiator. The hard coat film and the reflection preventing film using the photosensitive resin composition are also provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition excellent in a high refractive index and an antistatic function, a hard coat film using the resin composition, and an antireflection film.

  In recent years, an antireflection film or an antireflection film that prevents a decrease in contrast and reflection of an image due to reflection of external light has been used in various applications. A typical example of use is an antireflection film used to prevent reflection of external light on the outermost surface of an image display device such as a plasma display panel (PDP) or a liquid crystal display device (LCD). The antireflection film applied for such uses is required to have antistatic properties, surface hardness, low reflectance, high scratch resistance, antifouling properties, and the like.

  In response to these requirements, desired properties are exhibited by improving the composition of the resin composition as a raw material for the antireflection film and the like. For example, in Japanese Patent Application Laid-Open No. 2002-283509, an antireflection film includes a conductive layer containing conductive inorganic particles in a conductive layer and a resin layer made of a fluorine-containing copolymer containing a vinyl ether structure in the main chain. A laminated film is disclosed (Patent Document 1).

  Japanese Patent Application Laid-Open No. 2006-188588 discloses an antireflection film having an antistatic function, a high refractive index layer or a hard coat using two kinds of metal oxides of a conductive metal oxide and a transparent metal oxide. The photosensitive resin composition used for a layer is disclosed (patent document 2).

  Japanese Patent Application Laid-Open No. 2003-137912 discloses a polymerizable liquid composition and a crosslinked resin composition comprising a polymerizable monomer and semiconductor ultrafine particles (Patent Document 3).

JP 2002-283509 A JP 2006-188588 A JP 2003-137912 A

  When the conductivity of the conductive layer is expressed by using ITO or ATO to obtain a high refractive index, there arises a problem that the conductive layer is colored and the transmittance is lowered. In addition, in order to develop conductivity using other metal oxides, it is necessary to add a large amount, which affects other properties such as hardness. Specifically, when the amount of the metal oxide increases, the amount of the binder (resin) relatively decreases, which affects the strength of the cured composition itself (prone to cracking), scratch resistance, and the like. On the other hand, if the amount of the metal oxide exceeds 80%, haze increases (transmittance decreases).

Further, when a normal resin is used as a binder, since the surface resistance of the resin itself is high, it is difficult to obtain sufficient antistatic characteristics unless the surface resistance value of the metal oxide is 10 ³ Ω / □ or less. At this time, zinc antimonate having high conductivity and relatively high transparency is often used, but 75% or more needs to be added in order to increase the refractive index.

  Furthermore, since antimony compounds are environmentally hazardous substances, their use is limited.

  Furthermore, when a transparent oxide such as semiconductor fine particles is used, a high refractive index and transparency can be expressed if a predetermined amount is added, while the oxide has a low surface resistance value of the particle alone. Therefore, sufficient antistatic function cannot be exhibited.

In general, when the amount of conductive metal oxide such as ITO or ATO is increased in order to improve the antistatic property, the antistatic effect is improved, but the refractive index and transparency are inferior. Further, when the addition amount of a transparent metal oxide such as ZnO or TiO ₂ is increased in order to improve the refractive index, the refractive index is improved, but the antistatic property is inferior. Therefore, a hard coat film and an antireflection film having excellent characteristics in all of antistatic characteristics, high refractive index and transparency have been desired.

  Therefore, the present invention has a sufficient antistatic property, high refractive index and transparency when a cured film is formed, and does not use an environmental load substance, such as a plasma display panel (PDP), a liquid crystal display device (LCD), etc. It is an object of the present invention to provide a photosensitive resin composition suitable for a hard coat layer and a high refractive index layer of the image display device, a hard coat film using the resin composition, and an antireflection film.

  The present inventor has made various studies on the composition of the photosensitive resin composition that achieves a high refractive index and high transparency while maintaining excellent antistatic properties. By using a conductive auxiliary agent, the conductive metal It was found that a synergistic effect was exhibited with the oxide. The present invention is based on such findings, and includes at least a photocurable compound having three or more (meth) acryloyl groups, a photosensitive monomer having a polymerizable functional group and a polyether chain, a metal oxide, A photosensitive resin composition comprising a polymerization initiator is provided.

  By using a photosensitive monomer having a polymerizable functional group and a polyether chain as a conductive auxiliary agent, the cured film formed from the photosensitive resin composition of the present invention maintains high conductivity and transmittance. High refractive index. In addition, the reflectance can be kept low by applying and curing a low refractive index resin on the coating.

According to the photosensitive resin composition of the present invention, a transparent metal oxide having a surface resistivity of 10 ³ Ω / □ or more can be used as an antistatic agent, and the transmittance and refractive index are also conventional photosensitive resin compositions. Compared to Therefore, when forming a cured film, it has sufficient antistatic properties, high refractive index and transparency, and it is suitable for manufacturing hard coat films and antireflection films suitable for hard coat layers and high refractive index layers of image display devices. Is suitable. Moreover, since an environmentally hazardous substance is not used, it is preferable from the viewpoint of the environment.

  Next, an embodiment of the present invention will be described. The following embodiment is an example for explaining the present invention, and is not intended to limit the present invention only to this embodiment. The present invention can be implemented in various forms without departing from the gist thereof.

  The photosensitive resin composition of this embodiment contains the photocurable compound which has three or more (meth) acryloyl groups. By using a photocurable compound having three or more (meth) acryloyl groups, a cured film having a high surface hardness (having hard coat properties) can be obtained.

  As the photocurable compound having three or more (meth) acryloyl groups, for example, a (meth) acrylate monomer is preferably used. Suitable examples of the (meth) acrylate monomer include trimethylolpropane tri (meth) acrylate, pentaerythritol (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, and dipentaerythritol hexa. (Meth) acrylate etc. are mentioned.

  Furthermore, in combination with the photocurable compound having three or more (meth) acryloyl groups, a radical photosensitive monomer having two (meth) acryloyl groups and having an ether chain may be used. In this case, when the resin composition forms a cured film, an ether bond can be expected to increase the electronic conductivity of the cured film.

  Suitable examples of the radical type photosensitive monomer having two (meth) acryloyl groups and having an ether chain include triethylene glycol di (meth) acrylate, polyethylene glycol (meth) acrylate, and EO modification of bisphenol A. Examples include EO-modified compounds such as (meth) diacrylate.

  The photocurable compound preferably has 6 or more functional groups. When the photocurable compound has 6 or more functional groups, a cured film having higher surface hardness can be obtained.

  That is, the photocurable compound used in the photosensitive resin composition of the present embodiment has at least three (meth) acryloyl group functional groups. Moreover, it is preferable that the sum total of a functional group is six or more. At this time, a vinyl group, an allyl group, or a (meth) acryloyl group can be used as another functional group, and these can be used alone or in combination. When all the functional groups are (meth) acryloyl groups, there may be a combination of a vinyl group and a (meth) acryloyl group, a vinyl group, an allyl group, and a (meth) acryloyl group, or an allyl group and a (meth) acryloyl group.

  Specific examples of the photocurable compound having 6 or more functional groups include a polyfunctional urethane acrylate represented by the following formula (1).

  In the above formula, A represents a bifunctional or higher functional (meth) acrylate moiety, and I represents an isocyanate residue. Here, the “isocyanate residue” refers to an isocyanate compound after the reaction, and the isocyanate used in the present embodiment is a polyvalent isocyanate.

  The content of the photocurable compound having three or more (meth) acryloyl groups with respect to the total amount of solid content of the metal oxide, the photocurable compound, and the photosensitive monomer of 100 wt% is 5 to 60 wt%. %, Preferably 20 to 50 wt%. By setting the content of the photocurable compound having three or more (meth) acryloyl groups within such a range, the film strength is increased and sufficient antistatic ability can be exhibited. In addition, a high refractive index can be achieved.

  The photosensitive resin composition of this embodiment contains the photosensitive monomer which has a polymerizable functional group and a polyether chain as a conductive support agent. By using such a photosensitive monomer, it is possible to use a metal oxide having a high surface resistance value that could not be used conventionally, and to increase the conductivity of the cured film.

  The photosensitive monomer having a polymerizable functional group and a polyether chain is a photocationically polymerizable monomer having at least one photocationically polymerizable functional group or a photoanion polymerizable monomer having at least one photoanion polymerizable functional group. Preferably there is. In this example, a photocationically polymerizable monomer was used. Thereby, the reactivity improvement by dark reaction and the hardening defect by oxygen inhibition derived from a radical monomer can be suppressed. Further, the reaction proceeds even after UV light irradiation (dark reaction), and in addition, the reaction rate of the radical material is improved, and as a result, the film strength is improved.

It is preferable that three or more polyether chains are contained in one unit of the photosensitive monomer. When three or more of the polyether chains are contained in one unit of the photosensitive monomer, proton conduction derived from the ether chains appears. “Having a polyether chain” means having an ethylene oxide chain (CH ₂ CH ₂ O) in the skeleton.

  It is preferable that two or more of the polymerizable functional groups are contained in one unit of the photosensitive monomer. When two or more of the polymerizable functional groups are contained in one unit of the photosensitive monomer, the polymerization reaction is three-dimensionally cross-linked and the curability is improved.

  The polymerizable functional group is preferably, for example, a photocationically polymerizable functional group having an epoxy group, an oxetane group or a vinyl group, and more preferably a photocationically polymerizable functional group having a vinyl group. The reason is that the vinyl group can react with the (meth) acryloyl group, can be initiated with the photoradical initiator, and can be expected to react with the photoradical resin.

  Examples of the photocationically polymerizable monomer having a vinyl group and an ether chain include a vinyl ether compound represented by the following formula (2).

In the above formula, R ₁ represents H, an alkyl chain or a vinyl group, and B represents a vinyl group. N is an integer of 3 or more.

By using such a vinyl ether compound having an EO chain (CH ₂ C (R ₁ ) ₂ O), a highly polar resin, specifically, a photocurable compound having three or more (meth) acryloyl groups, More specifically, compatibility with a resin such as polyfunctional urethane acrylate can be enhanced. Moreover, since the said vinyl ether compound is low-viscosity, it can be utilized also as a reactive diluent. From the above characteristics, the vinyl ether compound can maintain a good dispersion state in the resin composition, and can form a dense conductive network in the photosensitive resin composition after curing.

  In addition, the cationic vinyl ether compound is excellent in adhesion to the substrate. The reason why the cationic vinyl group is preferable is that the reaction of the unreacted functional group is promoted by the dark reaction between the unreacted functional group of the polyfunctional urethane acrylate and the cationic vinyl group.

  Further, when the amount of the metal oxide is increased, the adhesion of the base material is generally lowered. However, the reaction can be gradually promoted by using a cationic vinyl ether compound. Thus, it is considered that curing shrinkage that occurs at the time of curing hardly occurs, and it is possible to suppress a decrease in adhesion with the base material.

  Furthermore, the surface curability and chemical resistance are improved by promoting the reaction of the unreacted functional group.

  When a metal oxide that absorbs ultraviolet rays (for example, gallium-doped zinc oxide) is used, it is preferable to use a cationic vinyl ether compound that proceeds by a cationic curing mechanism for the following reasons.

  According to the radical curing mechanism, the reaction is started by irradiating ultraviolet rays (hereinafter referred to as an initiation reaction), and the subsequent reaction (hereinafter referred to as a growth reaction) is affected by the initiation reaction. In contrast, the cationic curing mechanism, like the radical curing mechanism, starts reaction by irradiating with ultraviolet rays, but the subsequent growth reaction continues by heating without irradiating with ultraviolet rays. It progresses. Therefore, when a metal oxide that absorbs ultraviolet rays (for example, gallium-doped zinc oxide) is used, the cationic curing mechanism can be cured efficiently and uniformly.

FIG. 1 is a diagram for explaining a conductive mechanism of a photosensitive monomer having a polymerizable functional group and a polyether chain. Ether skeleton portion of the photosensitive monomer having a polymerizable functional group and a polyether chain, protons (H ⁺⁾ are generated in the system, among polyethers which the protons (H ⁺⁾ is adjacent the (inside the frame in the drawing) Proton conduction is expressed by movement. In FIG. 1, (+) represents a proton, and (−) represents an electron or unshared electron pair generated by the elimination of the proton. R1 represents an alkylene chain (methylene, ethylene chain, etc.).

  The content of the photosensitive monomer having a polymerizable functional group and a polyether chain is 5 to 15 wt% with respect to a total amount of 100 wt% of the solid content of the metal oxide, the photocurable compound, and the photosensitive monomer. It is preferable that By setting the content of the photosensitive monomer having a polymerizable functional group and a polyether chain in such a range, a sufficient conductive network can be formed and the antistatic performance can be improved.

  The photosensitive resin composition of this embodiment contains a metal oxide in order to impart antistatic properties. Since the metal oxide itself has UV-cutting ability, by using the metal oxide in the photosensitive resin composition, UV cut (cut at 360 nm or less) and light resistance can be imparted, and the cured film is deteriorated by irradiation with sunlight. Improved. As a result, it is not necessary to use a UV absorber in the photosensitive resin composition.

  As the metal oxide, at least zinc antimonate, tin oxide doped indium oxide (ITO), antimony doped tin oxide (ATO), antimony pentoxide, tin oxide, titanium oxide, cerium oxide, zinc oxide, aluminum doped zinc oxide, It is preferable to include one or more selected from the group consisting of gallium-doped zinc oxide. In particular, when the metal oxide is gallium-doped zinc oxide, since it has a function of cutting heat rays, an infrared cut function required in this field can be provided.

  From the viewpoint of transparency, the metal oxide is preferably particles having an average primary particle of 0.001 to 0.2 μm, and more preferably 0.005 to 0.001 μm. By setting the average particle diameter in such a range, aggregation of particles can be prevented in advance, and the problem of haze increase can be prevented.

  The content of the metal oxide is 20 to 20 wt% with respect to a total amount of solids of 100 wt% of the metal oxide, the photocurable compound, and the photosensitive monomer from the viewpoint of imparting conductivity and increasing the refractive index. It is preferable that it is 75 wt%.

  The photosensitive resin composition of this embodiment contains a photopolymerization initiator. The photopolymerization initiator may be a radical, cationic or anionic polymerization initiator.

  Preferable examples of the radical photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, diethoxyacetophenone, benzyl dimethyl ketal, 2-hydroxy-2,2 methylphenyl propylene. Non, 1-hydroxycyclohexyl phenyl ketone, benzophenone, 2,4,6-trimethylbenzoin diphenylphosphine oxide, 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2- Dimethylamino-1- (4-morpholinophenyl) -butan-1-one, Michler's ketone, isoamyl N, N-dimethylaminobenzoate, 2-chlorothioxanthone, 2,4-diethylthioxan Mention may be made of the emissions and the like. These polymerization initiators can be used alone or in combination of two or more.

  The addition amount of the radical polymerization initiator varies depending on the type, the type and amount ratio of the photocurable compound to be used, use conditions, and the like, but when the photocurable compound is 100 wt% in the photosensitive resin composition And 0.5 to 10 wt%.

  Preferable examples of the cationic polymerization initiator include diaryliodonium salts and triarylsulfonium salts in addition to sulfonium salts and ammonium salts. Moreover, a commercial item can also be used for a cationic polymerization initiator. Representative examples of commercially available products include trade names CI-1370, CI-2064, CI-2397, CI-2624, CI-2939, CI-2734, CI-2758, CI-2823, CI-2855 and CI-5102. Commercial products available under the trade name (manufactured by Nippon Soda Co., Ltd.), commercial products available under the trade name PHOTOINITIATOR 2047 (manufactured by Rhodia), commercial products available under the trade names UVI-6974 and UVI-6990 (Both manufactured by Union Carbide). These polymerization initiators can be used alone or in combination of two or more.

  The addition amount of the cationic polymerization initiator varies depending on the type, the type and amount ratio of the photocationic polymerizable monomer used, the use conditions, etc., but when the photocationic polymerizable monomer in the photosensitive resin composition is 100 wt% And 0.5 to 10 wt%.

  As a suitable example of the anionic polymerization initiator, for example, an alkali metal or an organic alkali metal can be exemplified, and examples of the alkali metal include lithium, sodium, potassium, cesium, sodium-potassium alloy and the like. As the organic alkali metal, alkylated products, allylated products, arylated products and the like of the above alkali metals can be used. Specifically, ethyllithium, n-butyllithium, sec-butyllithium, t-butyl Lithium, ethyl sodium, lithium biphenyl, lithium naphthalene, lithium triphenyl, sodium naphthalene, potassium naphthalene, α-methylstyrene sodium dianion, 1,1-diphenylhexyl lithium, 1,1-diphenyl-3-methylpentyl lithium, 1, - diphenylmethyl potassium, 1,4-dilithio-2-butene, 1,6-Jiri thio-hexane, polystyryllithium, can be mentioned cumyl potassium, Kumiruseshiumu, potassium semicarbazide like. These polymerization initiators can be used alone or in combination of two or more.

  The addition amount of the anion polymerization initiator varies depending on the type, the type and amount ratio of the photoanion polymerizable monomer to be used, use conditions, etc., but when the photoanion polymerizable monomer in the photosensitive resin composition is 100 wt% And 0.5 to 10 wt%.

  The photosensitive resin composition of the present embodiment includes a photocurable compound having three or more (meth) acryloyl groups that are photoradical resins, and a polymerizable functional group that is a photocationically polymerizable monomer or a photoanion polymerizable monomer. And photosensitive monomers having polyether chains. Accordingly, it is preferable that the photopolymerization initiator is used in combination by appropriately selecting a radical-based and cationic or anionic polymerization initiator according to the kind of the compound and the monomer.

  In addition, the combined use of radical-based and cationic or anionic polymerization initiators has the advantage of photo-radical reaction that the reaction rate is fast and is not affected by humidity, and there is dark reactivity without oxygen inhibition. The advantage of the photocation / photoanion reaction that the curing shrinkage is small is obtained. For example, the photoradical reaction is performed at the initial stage of the reaction, and thereafter, the reaction can be performed by a dark reaction by a cation system or an anion system.

  Moreover, also about the cured film obtained by reaction, since the ion remains in the cured film obtained by combining photoradical reaction and photocation or photoanion reaction, it can be expected that conductivity is improved. .

  In order to increase the efficiency of the photopolymerization initiator, a sensitizer, an amine-based additive, or a thiol-based curing accelerator may be used. In particular, a thiol-based curing accelerator is preferable because it can reduce oxygen inhibition when added in a small amount and can form a highly curable film.

  From the viewpoint of the dispersibility of the metal oxide and the resin, an organic solvent can be added to the photosensitive resin composition of the present embodiment. Preferable examples of the organic solvent include alcohols such as methanol, ethanol, n-propanol, isopropanol, and n-butanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; 2-methoxyethanol, 2-ethoxy Ethers such as ethanol, 2-butoxyethanol, 1-methoxy-2-propanol, ethylene glycol diethyl ether, diethylene glycol dimethyl ether; ethers such as 2-methoxyethyl acetate, 2-ethoxyethyl acetate, 2-butoxyethyl acetate Esters; aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate, propyl acetate, and butyl acetate;

  The addition amount of the organic solvent can be appropriately set according to the use conditions of the photosensitive resin composition (for example, the concentration conditions for application). Specifically, it is 10-9900 wt% with respect to 100 wt% of the total amount of the solid content of the photocurable compound, the photosensitive monomer, and the metal oxide.

  The photosensitive resin composition of the present embodiment can be applied to a substrate and then cured by photopolymerization to form a hard coat and / or an antistatic high refractive index layer. Furthermore, an antireflection film of a two-layer structure type or a three-layer structure type can be formed by forming a low refractive index layer on the hard coat film or the antistatic high refractive index layer. The antireflection film can be applied to an image display device such as a plasma display panel (PDP) or a liquid crystal display device (LCD).

FIG. 2 is a diagram for explaining a conductive mechanism when a hard coat film is formed by curing a photosensitive resin composition containing a metal oxide having a surface resistivity of 10 ³ Ω / □ or more. FIG. 2A is a schematic view of a conventional hard coat film, and FIG. 2B is a schematic view of the hard coat film of the present embodiment.

As shown in FIG. 2 (A), a conventional hard coat film not containing a photosensitive functional monomer having a polymerizable functional group and a polyether chain as a conductive auxiliary agent has a surface resistivity in a binder (insulator) 10. However, the electrical conductivity (EC) is weak if only the metal oxide 12 is present at 10 ³ Ω / □ or more.

  On the other hand, as shown in FIG. 2 (B), a hard coat film in which a photosensitive monomer 14 having a polymerizable functional group and a polyether chain, which is a conductive auxiliary agent, is blended with a binder (insulator) 10 and vinyl ether. Since chains are present, protons 16 are easily generated. As a result, the conductivity (EC) is stronger than that of the hard coat film of FIG. In FIG. 2B, (+) represents proton 16 and (−) represents an electron or unshared electron pair 18 generated by the elimination of the proton.

In addition, conductivity (EC) is expressed by the movement of protons 16, and even when metal oxide 12 having a surface resistivity of 10 ³ Ω / □ or more is added, the antistatic properties required in this field are expressed. Can be made.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples. Those skilled in the art can implement various modifications as well as the following embodiments, and such modifications are also included in the scope of the claims.

1. Preparation of photosensitive resin composition The photosensitive resin composition of an Example and a comparative example was prepared with the composition shown in Table 1. First, the polyfunctional urethane acrylate (D) which is a photocurable compound and the vinyl ether compound (E) which is a photosensitive monomer are added to the metal oxide (A, B, C), and the organic solvent (H) is added and stirred. Thereafter, a photopolymerization initiator (F, G) was added and stirred to obtain a desired photosensitive resin composition.

2. Production of Film (1) Production of Antistatic Hard Coat Film An antistatic hard coat film was produced using the above-described photosensitive resin composition. Using the bar coater, the above-mentioned photosensitive resin composition was applied on PET with easy adhesion. Next, after drying for 1 minute in a drying oven at 80 ° C., the photosensitive resin composition is cured by irradiating with ultraviolet rays so that the integrated light quantity becomes 400 mJ / cm ^{2 in} an air atmosphere, thereby 3 μm on the substrate. An antistatic hard coat film (refractive index: 1.75) having a coating film was obtained.

(2) Preparation of antireflection film having a two-layer structure Using a bar coater, the photosensitive resin composition of Example 2 was applied onto PET with easy adhesion so as to have a film thickness of 1 μm, and DPHA ( Diventaerythritol hexaacrylate) and a low refractive index metal oxide dispersion (MIBK-dispersed magnesium fluoride), a photopolymerization initiator, and an organic solvent composition were applied. Next, after drying in an oven at 80 ° C. for 1 minute, a 0.1 μm film was formed by irradiating and curing ultraviolet rays so that the accumulated light amount was 400 mJ / cm ^{2 in} a nitrogen atmosphere. Thus, an antireflection film having a two-layer structure in which an antistatic hard coat layer (refractive index: 1.75) and a low refractive index layer (refractive index: 1.43) were formed on a base material was obtained. In addition, even if it used the photosensitive resin composition of the other Example, the antireflection film was able to be manufactured similarly.

(3) Preparation of antireflection film having a three-layer structure A hard coat film composition having a composition comprising DPHA, a photopolymerization initiator, and an organic solvent is used to form a film thickness of 3 μm on easy-adhesion PET using a bar coater. After coating in a drying oven at 80 ° C. for 1 minute, the hard coat film composition is cured by irradiating the hard coat film composition by irradiating ultraviolet rays so that the integrated light quantity becomes 400 mJ / cm ^{2 in} an air atmosphere. A hard coat film was obtained. On top of that, the photosensitive resin composition of Example 2 was applied by a bar coater, dried for 1 minute in a drying oven at 80 ° C., and then irradiated with ultraviolet rays so that the accumulated light amount was 400 mJ / cm ^{2 in} an air atmosphere, By curing, a high refractive index antistatic layer having a 0.1 μm film was obtained. Further, a low refractive index resin composition comprising DPHA and a low refractive index metal oxide dispersion (MIBK-dispersed magnesium fluoride), a photopolymerization initiator, and an organic solvent is applied on the high refractive index antistatic layer. After drying in a drying furnace at 1 ° C. for 1 minute, ultraviolet rays were irradiated in a nitrogen atmosphere so that the integrated light amount was 400 mJ / cm ² to form a 0.1 μm film. As a result, a hard coat layer (refractive index: 1.51), a high refractive index antistatic layer (refractive index: 1.75), and a low refractive index layer (refractive index: 1.43) were formed on the substrate. An antireflection film having a three-layer structure was obtained. In addition, even if it used the photosensitive resin composition of the other Example, the antireflection film was able to be manufactured similarly.

3. Evaluation Test Using the antistatic hard coat film obtained in 2 (1) above as a sample, an evaluation test was performed on the following items.

(1) Total light transmittance This was measured using a haze meter (Haze Meter HM-150, manufactured by Murakami Color Research Laboratory).

(2) Haze value The haze value was measured using a haze meter (Haze Meter HM-150 manufactured by Murakami Color Research Laboratory).

(3) Antistatic property (prevention of dust adhesion) The surface of the sample was measured with a surface resistance meter (SME-8310 manufactured by Toa DKK Corporation) and evaluated as antistatic property (prevention of dust adhesion) at 10 ¹¹ Ω / □ or less. did.

(4) Scratch resistance The hardened film is rubbed 10 times with steel wool (manufactured by Nippon Steel Wool Co., Ltd., trade name: Bonster # 0000) at 200 g / cm ² , and a matte paint is applied. Observed and evaluated according to the following criteria.
○: 3 or less scratches △: 4 to 10 scratches ×: 10 or more scratches

(5) Pencil hardness It evaluated according to JISK5400. That is, the pencil was brought into contact with the surface of the cured film, five lines were drawn with a load of 1 kg, and evaluation was made by observing whether or not the scratch had reached the substrate. In addition, when there were not four or more scratches, it was determined as OK. Table 2 shows the pencil hardness at that time.

(6) Adhesiveness Measured according to JIS K 5400. That is, 100 square grids were made on the surface of the cured film at intervals of 1 mm at intervals of 1 mm, and after the cellophane tape was adhered to the surface, it was not peeled off at once, and the remaining grids remained. The number of was displayed.

(7) Wavelength cut (UV cut, infrared cut)
A wavelength of 380 nm or less was measured with a spectroscopic spectrometer (U-4100, manufactured by Hitachi High-Technologies Corporation), and the wavelength of the portion having a transmittance of 5% or less was observed. In the evaluation according to the present invention, the ultraviolet (UV) cut function means that the transmittance at a wavelength of 360 nm or less is 5% or less, and the infrared (IR) cut function has a function of 1600 nm or more. It was set as the case where the transmittance | permeability of a wavelength (near infrared rays) is 30% or less. FIG. 3 is an example of the spectral transmission spectrum of an antistatic hard coat film produced using the photosensitive resin composition of Example 2.

  Table 2 shows the results of the evaluation tests (1) to (7).

  As a result of the evaluation test, it was found that the antistatic hard coat film produced using the photosensitive resin composition of the example has a high refractive index while maintaining high conductivity and transmittance.

  In addition, since the leveling agent was added to the conventional resin composition for hard coats and the resin composition for high refractive indexes, the adhesiveness with a low refractive index layer was falling. On the other hand, since the photosensitive resin composition of the present invention does not require a leveling agent, adhesion to the low refractive index layer is improved.

(8) Measurement of reflectance The reflectance was measured using the antireflection film having the two-layer structure obtained in 2 (2) and the antireflection film having the three-layer structure obtained in 2 (3). . Specifically, the back surface of the antireflection film was roughened with # 400 sandpaper, and then a matte black paint was applied. Subsequently, the luminous average reflectance was measured with a reflectance measuring device (manufactured by Shimadzu Corporation, device name: UV-3150). The results are shown in Table 3 and FIG. FIG. 4 is a spectral reflection spectrum of an antireflection film having a two-layer structure formed using the photosensitive resin composition of Example 2. From the results of Table 3 and FIG. 4, the antireflection film having the two-layer structure and the antireflection film having the three-layer structure formed using the photosensitive resin composition of the example can suppress the reflectance low. confirmed.

It is a figure for demonstrating the electroconductivity mechanism of the photosensitive monomer which has a polymeric functional group and a polyether chain | strand. It is a figure for demonstrating the electroconductivity mechanism of a hard coat film. It is an example of the spectral transmission spectrum of an antistatic hard coat film. It is an example of the spectral reflection spectrum of an antireflection film.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Binder (insulator), 12 ... Metal oxide with surface resistivity of 10 ³ Ω / □ or more, 14 ... Photosensitive monomer having polymerizable functional group and polyether chain, 16 ... Proton, 18 ... Electron or non Shared electron pair, EC ... conductivity

Claims (13)

  A photosensitive resin comprising at least a photocurable compound having three or more (meth) acryloyl groups, a photosensitive monomer having a polymerizable functional group and a polyether chain, a metal oxide, and a photopolymerization initiator. Composition.   The photosensitive resin composition according to claim 1, wherein the photosensitive monomer having a polymerizable functional group and a polyether chain is a photocationically polymerizable monomer or a photoanion polymerizable monomer.   The photosensitive resin composition according to claim 1 or 2, wherein three or more of the polyether chains are contained in one unit of the photosensitive monomer.   The photosensitive resin composition according to claim 1, wherein two or more of the polymerizable functional groups are contained in one unit of the photosensitive monomer.   The photosensitive resin composition according to claim 1, wherein the polymerizable functional group is at least one selected from the group consisting of an epoxy group, an oxetane group, and a vinyl group.   The metal oxide is at least zinc antimonate, tin oxide-doped indium oxide (ITO), antimony-doped tin oxide (ATO), antimony pentoxide, tin oxide, titanium oxide, cerium oxide, zinc oxide, aluminum-doped zinc oxide, gallium The photosensitive resin composition of any one of Claims 1-5 containing 1 or more types selected from the group which consists of dope zinc oxide.   The photosensitive resin composition of any one of Claims 1-6 in which the said photocurable compound has a 6 or more functional group. The photosensitive resin composition of any one of Claims 1-7 whose photocurable compound which has the said 6 or more functional group is polyfunctional urethane acrylate shown to following formula (1).

(In the above formula, A represents a bifunctional or higher functional (meth) acrylate moiety, and I represents an isocyanate residue.) For a total amount of 100 wt% of the solid content of the metal oxide, the photocurable compound, and the photosensitive monomer,
The content of the photocurable compound having three or more (meth) acryloyl groups is 5 to 60 wt%,
The content of the photosensitive monomer having a polymerizable functional group and a polyether chain is 5 to 15 wt%,
The content of the metal oxide is 20 to 75 wt%,
The photosensitive resin composition of any one of Claims 1-8. The photocurable compound having three or more (meth) acryloyl groups is a polyfunctional urethane acrylate,
The photosensitive monomer having a polymerizable functional group and a polyether chain is a vinyl ether compound,
The metal oxide is gallium-doped zinc oxide;
The photosensitive resin composition of any one of Claims 1-9.   The hard coat film in which the photosensitive resin composition of any one of Claims 1-10 was formed on the base material.   The antireflection film in which the low refractive index layer which has a refractive index lower than the refractive index of the said hard coat film was formed on the hard coat film of Claim 11. A base material, a hard coat layer formed on the base material, a high refractive index layer formed on the hard coat layer and having a refractive index higher than that of the hard coat layer, and a high refractive index layer An antireflection film having a low refractive index layer formed thereon and having a refractive index lower than that of the high refractive index layer,
The antireflective film in which the said high refractive index layer was formed from the photosensitive resin composition of any one of Claims 1-10.

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