JP2009282364A - Resin composition for optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition for an optical element which can obtain a thin optical sheet excellent in optical characteristics, antistatic properties and scratch preventing properties. <P>SOLUTION: The resin composition for the optical element is characteristically contains: a polyurethane (meth)acrylate oligomer with at least three functional groups on the terminals (A component); a multifunctional (meth)acrylate monomer (B component); a styrene-(meth)acrylate copolymer (C component); an active energy ray sensitive polymerization initiator (D component); and a modified silicone oil containing an electrolytic salt (E component). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a resin composition (hereinafter simply referred to as “optical sheet”) that is used to manufacture an optical sheet (hereinafter sometimes simply referred to as “optical sheet”) that is mounted on the front surface of the display screen of display panels of various image display devices. In particular, the present invention relates to a resin composition for an optical element from which an optical sheet excellent in optical properties, antistatic properties, and scratch resistance can be obtained.

  In recent years, with the increase in size, thickness, and weight of liquid crystal televisions, plasma televisions, projection televisions, and the like, plastic optical sheets have been required to have higher performance. In particular, an optical sheet that is thin and excellent in optical characteristics, antistatic performance, and scratch resistance has become important for high performance.

  Conventionally, in the optical sheet made of plastic, since the surface of the base material is easily scratched, various plastic films imparted with performance such as the scratch resistance and further optical characteristics are provided on the surface of the base material. For example, after applying an ultraviolet curable adhesive to the surface of a transparent resin plate such as an acrylic resin plate that is a base of the optical sheet, the adhesive is sandwiched between the plastic films, and the base side The optical sheet was obtained by curing the adhesive by irradiating ultraviolet rays.

  As various plastic films provided on the base material surface of the optical sheet, a plastic film having a certain kind of antireflection film and a manufacturing method thereof (Patent Document 1) are disclosed. In the plastic film disclosed in Patent Document 1, an antireflection film is formed on one side of a film substrate made of a resin mainly composed of polyethylene terephthalate having a size of 50 μm to 250 μm, and an adhesive layer is formed on the other side. As can be seen in the examples, a hard coat layer having scratch resistance on the film and an optical characteristic film of an antireflection film of an inorganic thin film are formed on the coat layer, and the obtained film Is adhered to the display surface using an ultraviolet curable adhesive.

  However, since the display panel having the plastic film disclosed in Patent Document 1 attached to the front side is bonded with a film having a multilayer coating layer to which various performances are added, it also increases manufacturing effort and costs. Since the coated plastic film itself has a thickness, the display panel becomes thick and obstructs the thinning of the display panel. In addition, the optical characteristics such as transparency and image quality are deteriorated.

  From the above, it is possible to form a thin film by applying directly to the optical sheet base material without using the plastic film with the above-mentioned various performances added, optical properties, antistatic properties, and scratch prevention. There is a demand for a resin composition for an optical element that can provide an optical sheet having excellent properties.

JP-A-9-193327

  Accordingly, the object of the present invention is excellent in optical characteristics, antistatic properties, and scratch resistance (sometimes these performances are collectively referred to as “optical element characteristics”), and a thin optical sheet is obtained. It is providing the resin composition for optical elements obtained.

  As a result of intensive studies to solve the above problems, the present inventor forms a thin film coating film directly on the optical sheet substrate by using the optical element resin composition comprising the following specific components. The present inventors have found that a thin optical sheet having excellent optical element characteristics, such as transparency, haze, surface resistance, coating film hardness, scratch resistance, and adhesion, can be produced economically. That is, the present invention relates to a polyurethane (meth) acrylate oligomer (component A) having at least three functional groups at its terminal, a polyfunctional (meth) acrylate monomer (component B), and a styrene- (meth) acrylate copolymer. Provided is a resin composition for an optical element comprising (C component), an active energy ray functional polymerization initiator (D component), and a modified silicone oil (E component) containing an electrolyte salt. To do.

（上記式中、Ｒ１は、炭素数が１〜４のアルキル基、炭素数が６〜８のアリール基、炭素数が７〜９のアラルキル基を表す。なお、上記の基は、いずれも水酸基を有していてもよい。また、Ｒ２〜Ｒ４は、いずれもアルキレン基を、Ｒ５は、水素原子または１価の有機基を表す。また、ｍは、０〜１００の整数を、ｎは、１〜１００の整数を表す。また、ｘおよびｙは、０〜１００の整数を表し、それぞれが同時に０とならない整数である。）、Ａ成分１００質量部に対して、Ｂ成分が２０〜４０質量部、Ｃ成分が１０〜２０質量部、Ｄ成分が５〜１５質量部、およびＥ成分が０．２〜１５質量部の配合割合であり、Ａ成分の重量平均分子量が１，０００〜３，０００であり、Ｂ成分が、トリプロピレングリコールジアクリレートおよび／またはジペンタエリスリトールヘキサアクリレートであり、および、Ｃ成分の重量平均分子量が６０，０００〜９０，０００、酸価が０ｍｇＫＯＨ／ｇであるのが好ましい。 Moreover, in preferable embodiment of this invention, the said E component contains the quantity which 0.2-10 mass% occupies in the resin composition solid content total amount, and the said electrolyte salt is lithium perchlorate. And at least one selected from lithium iodide, lithium thiocyanate, lithium borofluoride, and lithium tetrafluoromethanesulfonate, and the modified silicone oil has a molecular structure represented by the following general formula (1) Is,

(In the above formula, R1 represents an alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 8 carbon atoms, or an aralkyl group having 7 to 9 carbon atoms. Note that each of the above groups is a hydroxyl group. R2 to R4 each represents an alkylene group, R5 represents a hydrogen atom or a monovalent organic group, m represents an integer of 0 to 100, and n represents Represents an integer of 1 to 100. Further, x and y represent an integer of 0 to 100, and each is an integer that does not simultaneously become 0.), B component is 20 to 40 with respect to 100 parts by mass of A component The blending ratio is 10 to 20 parts by mass, the C component is 5 to 15 parts by mass, the D component is 5 to 15 parts by mass, and the E component is 0.2 to 15 parts by mass. The weight average molecular weight of the A component is 1,000 to 3 1,000, and the B component is tripropylene glycol diacrylate and / or Is dipentaerythritol hexaacrylate, and the weight average molecular weight of the component C is 60,000～90,000, preferably an acid value of 0 mgKOH / g.

Further, the present invention provides an optical sheet characterized by having a coating film obtained by applying the resin composition of the present invention to a substrate for optical elements and curing it with ultraviolet rays, and a surface resistance value of the coating film of the optical sheet. An optical sheet that is 10 ¹² Ω / □ or less is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the resin composition for optical elements which can manufacture the thin optical sheet excellent in the optical element characteristic cheaply and economically is provided.

  Next, the present invention will be described in more detail with reference to the best mode for carrying out the invention. The component A used in the present invention is a polyurethane (meth) acrylate oligomer having at least 3 functional groups, preferably about 10 functional groups at the terminal, and any known polyurethane (meth) acrylate oligomer may be used. Can also be used. The oligomer includes, for example, an isocyanate having three or more isocyanate groups, a polyfunctional (meth) acrylate having at least one hydroxyl group and two (meth) acryloyloxy groups (“(meth) acrylate” is an acrylate And a reaction product of polyhydric alcohols having at least two hydroxyl groups. Examples of the isocyanates used in the above reaction product include triphenylmethane triisocyanate, dimethylene triphenyl triisocyanate, isocyanurate of isophorone diisocyanate, isocyanurate of hexamethylene diisocyanate, biuret of isophorone diisocyanate, And bimuret of hexamethylene diisocyanate.

  Examples of the polyfunctional (meth) acrylates used in the reaction products include trimethylolpropane di (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, Pentaerythritol penta (meth) acrylate, polypentaerythritol poly (meth) acrylate, ditrimethylolpropane di (meth) acrylate, glycerin di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, Ditrimethylolpropane tetra (meth) acrylate, glycerin tri (meth) acrylate, pentaerythritol (meth) acrylate, dipentaerythritol hexa (meth) acrylate Rate and the like.

  Examples of the polyhydric alcohol used in the reaction product include 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, ethylene glycol, diethylene glycol, propylene glycol, and dipropylene. Examples include glycol, trimethylolpropane, ditrimethylolpropane, neopentylglycol glycerin, pentaerythritol, dipentaerythritol, polypentaerythritol, 2-methyl-2-butyl-1,3-propanediol.

  The component A used in the present invention is an oligomer obtained by reacting each of the above components by a known method, and the oligomer has a weight average molecular weight of 1,000 to 3,000, preferably 1, The thing of 500-2500 is mentioned. The above-mentioned oligomer can be obtained from Nippon Synthetic Chemical Co., Ltd. under a trade name such as “purple light UV-1700B” and used in the present invention. When the above weight average molecular weight is too high, the coating property of the resulting resin composition is lowered. On the other hand, when the weight average molecular weight is too low, the scratch resistance of the resulting coating film is lowered. In addition, the weight average molecular weight in this invention is the value of the molecular weight of polystyrene conversion calculated | required with GPC measuring method.

  The component B used in the present invention is a photopolymerizable bifunctional or higher functional (meth) acrylate monomer. Examples of the B component include 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and diethylene glycol di (meth). Di (meth) acrylates such as acrylate, neopentyl glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate; pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) ) Acrylate, dipentaerythritol penta (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaglycerol tri (meth) acrylate Trifunctional or higher (meth) acrylates such as pentaerythritol tri (meth) acrylate, glycerin tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, tripentaerythritol tetra (meth) acrylate, tripentaerythritol penta (meth) acrylate, etc. Etc., preferably tripropylene glycol diacrylate and / or dipentaerythritol hexaacrylate.

  The component C used in the present invention is a styrene- (meth) acrylate copolymer. The above copolymer includes styrenes such as styrene, p-methylstyrene, o-methylstyrene, m-methylstyrene, α-methylstyrene, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meta ) Acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, sec-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, n-pentyl (meth) acrylate, 2-hydroxy Mainly composed of (meth) acrylates such as ethyl (meth) acrylate, benzyl (meth) acrylate, aminoethyl (meth) acrylate, glycidyl (meth) acrylate, and (meth) acrylic acid, itaconic acid, maleic acid Unsaturated Bon acid or anhydride thereof, carboxylic acid vinyl esters optionally, a vinyl cyanide compound, a copolymer obtained by reacting the like aliphatic conjugated diene compound. Examples of the copolymer include copolymers such as benzyl methacrylate / styrene / methacrylic acid and benzyl methacrylate / styrene / methacrylic acid / glycidyl methacrylate.

  Examples of the component C include those having a weight average molecular weight of 60,000 to 90,000, more preferably 85,000 to 90,000 and an acid value of 0 mgKOH / g. The C component can be obtained from Mitsubishi Rayon Co., Ltd. under the trade name “Dianar BR-52” and used in the present invention. When the above weight average molecular weight is too high, the coating property of the resulting resin composition is lowered. On the other hand, when the weight average molecular weight is too low, the scratch resistance of the resulting coating film is lowered. Moreover, when the acid value is too high, the alkali resistance of the resulting coating film is lowered.

  Moreover, as D component used by this invention, a well-known photoinitiator can be used and generate | occur | produces the activity which can start superposition | polymerization by active energy rays, such as an ultraviolet-ray, a far-ultraviolet ray, an electron beam, and an X-ray. A compound. As the polymerization initiator, biimidazole, benzophenone, benzoin, acetophenone, xanthone, triazine, anthraquinone, benzyl, diazo, α-diketone, oxime ester, etc., preferably acetophenone Is mentioned. The above polymerization initiator can be used in combination with a known sensitizer, curing accelerator, or the like, if necessary.

  Examples of the photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, diethoxyacetophenone, 2-methyl-1- (4-methylthiophenyl). ) -2-morpholinopropan-1-one and the like, preferably 1-hydroxycyclohexyl phenyl ketone.

  The E component used in the present invention is a modified silicone oil containing an electrolyte salt. The above-mentioned modified silicone oil is a reactive modified silicone oil or a non-reactive silicone oil, and has reactivity or reaction at any of the side chain, both ends, side chain and both ends, or one end of organopolysiloxane. It has a structure in which a functional organic group having no property is introduced. Examples of the organic group include an organic group having no reactivity other than a methyl group, and an organic group having a chemical reaction with various polymers. For example, a methylstyrene group, a long-chain alkyl group, a polyether group, carbinol Groups, amine groups, epoxy groups, carboxyl groups, higher fatty acid groups, mercapto groups, methacryl groups and the like.

（上記式中、Ｒ１は、炭素数が１〜４のアルキル基、炭素数が６〜８のアリール基、炭素数が７〜９のアラルキル基を表す。なお、上記の基は、いずれも水酸基を有していてもよい。また、Ｒ２〜Ｒ４は、いずれもアルキレン基を、Ｒ５は、水素原子または１価の有機基を表す。また、ｍは、０〜１００の整数を、ｎは、１〜１００の整数を表す。また、ｘおよびｙは、０〜１００の整数を表し、それぞれが同時に０とならない整数である。） As the modified silicone oil, a known reactive modification such as a side chain type, a single terminal type, a side chain both terminal type, or a both terminal type having a structure in which a functional organic group is introduced into the organopolysiloxane molecule is used. Examples of the silicone oil and the non-reactive silicone oil include those having a molecular structure represented by the following general formula (1).

(In the above formula, R1 represents an alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 8 carbon atoms, or an aralkyl group having 7 to 9 carbon atoms. Note that each of the above groups is a hydroxyl group. R2 to R4 each represents an alkylene group, R5 represents a hydrogen atom or a monovalent organic group, m represents an integer of 0 to 100, and n represents And represents an integer of 1 to 100. Also, x and y represent an integer of 0 to 100, and each is an integer that does not simultaneously become 0.)

  Specific examples of the modified silicone oil of the general formula (1) include, for example, in the general formula (1), R1 is a methyl group, R2 is a propylene group, R3 is an ethylene group, R4 is a propylene group, and R5 is a methyl group. And m is 2 to 40, n is 2 to 20, x is 0 to 20, and y is 0 to 20.

  As the electrolyte salt to be contained in the modified silicone oil, for example, thiocyanate such as lithium, sodium, potassium, magnesium, calcium, barium, perchlorate, trifluoromethanesulfonate, and halogenate, preferably Examples thereof include at least one selected from lithium perchlorate, lithium iodide, lithium thiocyanate, lithium borofluoride, and lithium tetrafluoromethanesulfonate. The electrolyte salt is contained in the modified silicone oil and dissolved in ions to impart antistatic properties to the modified silicone oil.

  The resin composition for an optical element of the present invention is preferably 20 to 40 parts by mass of the B component, 10 to 20 parts by mass of the C component, and 5 to 15 parts by mass of the D component with respect to 100 parts by mass of the A component. , E component is blended at a blending ratio of 0.2 to 15 parts by mass, other organic solvent and additives as necessary are blended, and uniformly mixed and stirred. The said organic solvent is suitably added for the purpose of the viscosity adjustment of the resin composition for optical elements obtained, or a coating suitability, Preferably the compounding quantity is 20-80 mass% in the resin composition total amount for optical elements.

  Examples of the organic solvent include alkylene glycol alkyl ether acetates such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene glycol monopropyl ether acetate; methyl ethyl ketone, acetone, methyl amyl ketone, methyl isobutyl ketone, and cyclohexanone. Ketones such as; methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 2-ethoxypropionate, methyl 2-methoxypropionate, ethyl lactate, butyl acetate; 3-methoxybutyl acetate, 3 -Alkoxyalkyl acetates such as methoxypentyl acetate and 3-methyl-3-methoxybutyl acetate; Diethylene glycol dialkyl ethers such as methyl dimethyl ether, diethylene glycol diethyl ether and diethylene glycol dibutyl ether; Ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate; Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, etc. Alkylene glycol monoalkyl ethers of: alcohols such as ethanol, propanol, butanol, 3-methoxybutanol, 3-methyl-3-methoxybutanol, cyclohexanol, ethylene glycol, glycerin; aromatics such as toluene and xylene, And mixtures thereof.

  As the above-mentioned additives, various modified silicone resins, preferably modified silicone acrylic resins (organic modified) are used in order to impart toughness of the coating film of the resin composition for optical elements to be obtained within the range not impairing the object of the present invention. Silicone acrylate), and acrylic silane coupling agents, epoxy silane coupling agents, ultraviolet absorbers such as alkoxybenzophenone, 2,2-thiobis ( Mats such as 4-methyl-6-tbutylphenol) and other surfactants, silicone-based surfactants for improving the smoothness of coating films, other antifoaming agents, anti-aggregation agents, silica, acrylic fillers, etc. Materials. The above modified silicone acrylic resin can be obtained from Tego Chemie Service GmbH under the trade name “TegoRad2100” and used in the present invention.

The resin composition for an optical element prepared as described above is a known optical sheet substrate, for example, transparent (total light transmittance of 80% or more, haze of 2% or less) styrene acrylic, polymethacrylic, polyester Gravure roll coating, roll coating, spin coating on the front surface of a display member having a thickness of 0.1 mm to 5 mm, preferably 1 mm to 2 mm made of polymer resin such as polycarbonate, polystyrene, polyacetate, polyarylate, polyethersulfone It is applied by a known application method such as casting application or dip application, and dried by heating to obtain a coating film of 1 to 5 μm. Next, the coating film is cured by irradiating the coating film with, for example, a high-pressure mercury lamp or an ultra-high pressure mercury lamp (900 mJ / cm ² light amount) to obtain an optical sheet. The obtained optical sheet may be either a film or a plate.

The surface resistance value of the UV-cured coating film of the obtained optical sheet is preferably 10 ¹² Ω / □ or less, more preferably 10 ⁷ Ω / □ to 10 ¹¹ Ω / □. If the surface resistance value of the coating film is too high, the antistatic property of the coating film surface of the obtained optical sheet is lowered, and dust and dust in the air are likely to adhere, and as a surface member of the display device screen Optical properties are degraded. In addition, said surface resistance value represents the resistance value per unit surface area measured based on JISK6911.

  Further, the haze of the obtained optical sheet is 2% or less, preferably 1.5% or less, close to the optical sheet substrate. If the haze value of the optical sheet is too large, the resulting optical sheet is in a hazy state, and the optical properties are deteriorated such that the image is not clearly visible as a surface member of the display device screen. In addition, said haze is the value measured by Murakami Color Research Laboratory make and haze meter HM-150 type | mold based on JISK7136 and JISK7361.

  Next, the present invention will be described more specifically with reference to resin compositions for optical elements J1 to J3 of the present invention and resin compositions for optical elements K1 to K6 of comparative examples. In the text, “part” or “%” is based on mass. In addition, this invention is not limited to the following Example.

[Examples 1 to 3] (Resin compositions for optical elements J1 to J3)
The following A component, B component, C component, D component, E component, organic solvent, and additive are blended as shown in Table 1 and mixed uniformly to obtain resin compositions for optical elements J1 to J1. J3 was prepared.

Each of the above components is as follows.
A component: Polyurethane acrylate oligomer (manufactured by Nippon Synthetic Chemical Co., Ltd., “purple light UV-1700B”, weight average molecular weight 2,000, functional group number 10)
B component: polyfunctional acrylate monomer B1: tripropylene glycol diacrylate, B2: dipentaerythritol hexaacrylate C component: styrene-acrylate copolymer (manufactured by Mitsubishi Rayon Co., Ltd., “Dyanal BR-52”, weight (Average molecular weight 85,000, acid value 0 mgKOH / g)
D component: 1-hydroxycyclohexyl phenyl ketone E component: modified silicone oil containing lithium perchlorate (in the general formula (1), R1 is a methyl group, R2 is a propylene group, R3 is an ethylene group, R4 2/3 parts by mass of lithium perchlorate is added to 1 part by mass of organopolysiloxane in which R is a propylene group and R5 is a methyl group, m is 30, n is 10, x is 0, and y is 10 Mixed)
Additive: Modified silicone resin (Organic modified silicone acrylate, Tego Chemie Service GmbH, TegoRad 2100)

[Comparative Examples 1 to 6] (Resin compositions for optical elements K1 to K6)
A component or A ′ component (polyurethane acrylate oligomer having 2 functional groups (manufactured by Nippon Synthetic Chemical Co., Ltd., “purple light UV-3000B”, weight average molecular weight 18,000, functional group number 2), B component, C component , D component, and E component instead of polyoxyethylene alkyl ether sulfate ester salt (E′1), quaternary ammonium salt (E′2), or anionic alkyl sulfonate (E′3) And it mix | blended like Table 1 and mixed uniformly, and prepared the resin composition K1-K6 for optical elements.

The compatibility of the components constituting the resin composition of the optical element resin compositions J1 to J3 and K1 to K6 obtained in the above Examples and Comparative Examples, and also using the resin composition, It was coated on a 1 mm transparent styrene acrylic resin plate with a gravure roll coater (dry thickness 2 μm), pre-dried for 3 minutes in an atmosphere at 80 ° C., and then 900 mJ / cm ² using an ultrahigh pressure mercury lamp. A sample of an optical sheet on which a UV-cured coating film was formed by irradiating ultraviolet rays with a light amount of, and using the sample, transparency, haze, surface resistance value, coating film hardness, scratch resistance, and adhesion Were evaluated by the following measurement methods. In addition, the above samples were allowed to stand for 5 days under the conditions of 60 ° C. and 90% humidity, and the transparency, haze, and surface resistance value after the standing were measured. The evaluation results are shown in Table 2.

(Compatibility)
The resin composition was visually observed and evaluated by the following evaluation method.
○: The resin composition is completely transparent, and the compatibility of each component is good.
X: The resin composition is in an opaque state, and the compatibility of each component is not good.

(transparency)
The transparent state of the coating film was visually observed and evaluated by the following evaluation method.
○: Bleeding or the like is not generated on the surface of the coating film, and the coating film is not clouded.
X: Bleeding or the like occurs on the surface of the coating film, and clouding of the coating film is observed.

(Haze)
Haze meter HM-150 manufactured by Murakami Color Research Laboratory Co., Ltd. is used to determine whether an image can be clearly seen using the styrene acrylic plate on which the coating film is formed, based on JIS K 7136 and JIS K 7361. Measured using a mold.

(Surface resistance value)
Based on JISK 6911, the resistance value per unit surface area was measured.

(Coating hardness)
The coating film hardness was measured by a pencil hardness test in accordance with JIS K 5600-5-4.

(Abrasion resistance)
Using a HEIDON TYPE 14DR manufactured by Shinto Kagaku Co., Ltd., the coating surface was rubbed 10 times with steel wool # 0000 at an overload of 500 g / 2 cm square, and the state of scratches after rubbing was evaluated by the following evaluation method. .
○: Scratches are not recognized on the coating surface.
X: Scratches are observed on the coating surface.

(Adhesion)
Based on JIS K 5600-5-6, the peeling state in the 100 scale grid of the coating film was measured by the grid tape method.
○: No peeling of the coating film is observed.
X: Peeling is recognized in the coating film.

  From the above evaluation results, by using the resin composition for an optical element of the present invention, transparency and optical properties such as haze, antistatic property from surface resistance value, coating film hardness, It has been proved that an optical sheet having optical element characteristics excellent in scratch resistance and scratch resistance rather than adhesion can be obtained. On the other hand, the optical sheet obtained using the resin compositions for optical elements of Comparative Examples 1 and 5 has a high surface resistance value and poor antistatic properties. Moreover, the adhesiveness of the optical sheet obtained using the resin composition for optical elements of Comparative Example 2 is inferior, and the coating film hardness of the optical sheet obtained using the resin composition for optical elements of Comparative Example 3 is inferior. In either case, scratch resistance is poor. Moreover, since the haze of the optical sheet obtained by using the resin composition for an optical element of Comparative Example 4 is high, the sharpness of the object to be clearly seen is hindered and the optical properties are inferior. Moreover, the resin composition for optical elements of Comparative Example 6 is not practical because the resin composition itself has poor compatibility.

  Since the optical element resin composition of the present invention has excellent optical element characteristics, it is used for producing an optical sheet that is a surface member of a display panel of an image display device such as a liquid crystal television, a plasma television, or a projection television. It can be used effectively as a material.

Claims (10)

  A polyurethane (meth) acrylate oligomer (A component) having at least three functional groups at its terminal, a polyfunctional (meth) acrylate monomer (B component), a styrene- (meth) acrylate copolymer (C component), A resin composition for optical elements, comprising an active energy ray functional polymerization initiator (D component) and a modified silicone oil (E component) containing an electrolyte salt.   The resin composition according to claim 1, wherein the E component is contained in an amount of 0.2 to 10% by mass in the total resin composition solid content.   The resin composition according to claim 1 or 2, wherein the electrolyte salt is at least one selected from lithium perchlorate, lithium iodide, lithium thiocyanate, lithium borofluoride, and lithium tetrafluoromethanesulfonate. The resin composition according to any one of claims 1 to 3, wherein the modified silicone oil has a molecular structure represented by the following general formula (1).

(In the above formula, R1 represents an alkyl group having 1 to 4 carbon atoms, an aryl group having 6 to 8 carbon atoms, or an aralkyl group having 7 to 9 carbon atoms. Note that each of the above groups is a hydroxyl group. R2 to R4 each represents an alkylene group, R5 represents a hydrogen atom or a monovalent organic group, m represents an integer of 0 to 100, and n represents And represents an integer of 1 to 100. Also, x and y represent an integer of 0 to 100, and each is an integer that does not simultaneously become 0.)   B component is 20-40 parts by mass, C component is 10-20 parts by mass, D component is 5-15 parts by mass, and E component is 0.2-15 parts by mass with respect to 100 parts by mass of component A The resin composition according to any one of claims 1 to 4.   The resin composition according to claim 1 or 5, wherein the weight average molecular weight of the component A is 1,000 to 3,000.   The resin composition according to claim 1 or 5, wherein the component B is tripropylene glycol diacrylate and / or dipentaerythritol hexaacrylate.   The resin composition according to claim 1 or 5, wherein the weight average molecular weight of component C is 60,000 to 90,000, and the acid value is 0 mgKOH / g.   An optical sheet comprising a coating film obtained by applying the resin composition according to any one of claims 1 to 8 to a substrate for optical elements and curing the composition with ultraviolet rays. The optical sheet according to claim 9, wherein a surface resistance value of the optical sheet coating film is 10 ¹² Ω / □ or less.