JP2009057440A - Energy ray-curable resin composition for optical use and its cured product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an energy ray-curable resin composition for optical use, which excels in mold releasability, mold copying nature and adhesion to a substrate, has a high refractive index and a high glass transition temperature, has light diffusibility and is good in storage stability. <P>SOLUTION: The energy ray-curable resin composition for optical use comprises a monoacrylate monomer having a phenyl ether group (A), inorganic fine particles having an average particle size of 0.1-2 μm (B) and/or organic fine particles having an average particle size of 0.1-5 μm (B'), and a photopolymerization initiator (C). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical energy ray-curable resin composition and a cured product thereof. More specifically, the present invention relates to a resin composition and a cured product particularly suitable for lenses such as a Fresnel lens, a lenticular lens, a prism lens, and a microlens.

  Conventionally, the above-described lens has been molded by a method such as a press method or a cast method (casting method). The former pressing method was poor in productivity because it was manufactured by heating, pressurizing and cooling cycles. Further, the latter casting method has a problem that it takes a long manufacturing time because a monomer is poured into a mold for polymerization, and a manufacturing cost increases because a large number of molds are required. In order to solve such a problem, various proposals have been made for using an ultraviolet curable resin composition (Patent Documents 1 and 2).

  A method for producing an optical lens sheet used for a transmission screen or the like using these ultraviolet curable resin compositions is known. However, the cured products of these conventional resin compositions have poor adhesion to the substrate and releasability from the mold. If the adhesion is poor, the types of substrates that can be used are limited, and the intended optical properties are difficult to obtain. If the releasability is poor, the resin remains in the mold at the time of mold release, and the mold cannot be used. In addition, a resin composition that gives a cured product with good adhesion is likely to have poor mold releasability because of good adhesion to the mold, while a resin composition with good mold releasability tends to have poor adhesion. is there. Therefore, it is desired to provide a resin composition that can satisfy both the adhesion to the substrate and the releasability from the mold, and Patent Document 3 is proposed.

  These optical lens sheets and the like are processed into finer shapes and processed thinner with recent high-definition images and the like. In order to prevent crushing of the shape when wound up, such as continuous processing is increasing, and so that there is little change in physical properties even under high temperature environment when using optical sheets in actual products, There is a tendency that a glass transition temperature (Tg) as high as possible is required. In addition, these optical lens sheets are usually used in combination with a diffusion sheet or the like, but it is desired to have a lens function and a diffusion performance with as few structures as possible. That is, what has light diffusibility is desired, maintaining a high refractive index, a high Tg point, mold release property, and adhesiveness.

  Patent Document 4 describes a light diffusing prism sheet containing a bead-shaped crosslinked acrylic resin having an average particle size of 10 μm.

JP 63-167301 A JP-A 63-199302 Japanese Patent No. 3209554 JP-A-9-304606

  The object of the present invention is to provide a resin composition with good storage stability suitable for producing optical lens sheets such as a Fresnel lens, a lenticular lens, a prism lens, a microlens, and a sheet lens, mold release property, mold reproducibility, An object of the present invention is to provide a cured product of the resin composition having excellent adhesion, high refractive index and light diffusibility.

  As a result of intensive studies to solve the above problems, the present inventors have found that an ultraviolet curable resin composition having a specific composition and a cured product thereof can solve the above problems, and have completed the present invention.

That is, the present invention relates to (1) a monoacrylate monomer (A) having a phenyl ether group, inorganic fine particles (B) having an average particle size of 0.1 μm to 2 μm, and / or organic fine particles having an average particle size of 0.1 μm to 5 μm. (B ′) and an energy ray-curable resin composition for an optical lens sheet comprising a photopolymerization initiator (C);

(2) The resin composition according to the above (1), wherein the monoacrylate monomer (A) having a phenyl ether group is o-phenylphenol polyethoxy (meth) acrylate;
(3) The resin composition according to the above (1) or (2), wherein the inorganic fine particles (B) are inorganic fine particles having a hydrophobic surface.

(4) The resin composition according to any one of (1) to (3), further including a polyfunctional (meth) acrylate monomer (D) having 3 or more (meth) acryloyl groups in the molecule. ;
(5) Further, a (meth) acrylate compound (E) other than a monoacrylate monomer (A) having a phenyl ether group and a polyfunctional (meth) acrylate monomer (D) having three or more (meth) acryloyl groups in the molecule ) Containing the resin composition according to any one of (1) to (4) above;

(6) A cured product having a refractive index at 25 ° C. of 1.55 or more obtained by curing the resin composition according to any one of (1) to (5) above;
(7) Hardened | cured material which provided the lens shape by shape | molding the resin composition as described in any one of said (1) thru | or (5) on a base film;
(8) An optical lens sheet using the cured product according to the above (6) or (7);
About.

  The resin composition of the present invention has good storage stability, and its cured product has excellent releasability, mold reproducibility, and adhesion to a substrate, and has a high refractive index and light diffusibility. Therefore, it is particularly suitable for use as an optical lens sheet such as a Fresnel lens, a lenticular lens, a prism lens, or a microlens.

The energy ray curable resin composition for an optical lens sheet of the present invention has a monoacrylate monomer (A) having a phenyl ether group, inorganic fine particles (B) having an average particle diameter of 0.1 μm to 2 μm, and / or an average particle diameter. Organic fine particles (B ′) of 0.1 μm to 5 μm, and a photopolymerization initiator (C) are included.
Examples of the monoacrylate monomer (A) having a phenyl ether group contained in the resin composition of the present invention include phenoxyethyl (meth) acrylate, phenyl polyethoxy (meth) acrylate, p-cumylphenoxyethyl (meth) acrylate, Examples include bromophenyloxyethyl (meth) acrylate and o-phenylphenol polyethoxy (meth) acrylate, and o-phenylphenol polyethoxy (meth) acrylate is preferred.

The o-phenylphenol polyethoxy (meth) acrylate is preferably a compound having an average number of repeating ethoxy structure moieties of 1 to 3, and (meth) acrylic as a reaction product of o-phenylphenol and ethylene oxide. It can be obtained by reacting an acid.
A reaction product of o-phenylphenol and ethylene oxide can be obtained by a known method, and a commercially available product can also be used. Next, in the presence of an esterification catalyst such as p-toluenesulfonic acid or sulfuric acid, and a polymerization inhibitor such as hydroquinone or phenothiazine, preferably the presence of solvents (for example, toluene, cyclohexane, n-hexane, n-heptane, etc.) The o-phenylphenol polyethoxy (meth) acrylate is obtained by reacting with (meth) acrylic acid at a temperature of preferably 70 to 150 ° C. below. The use ratio of (meth) acrylic acid is 1 to 5 mol, preferably 1.05 to 2 mol, per 1 mol of the reaction product of p-phenylphenol and ethylene oxide. An esterification catalyst is 0.1-15 mol% with respect to the (meth) acrylic acid to be used, Preferably it is 1-6 mol%.

  The resin composition of the present invention contains inorganic fine particles (B) having an average particle size of 0.1 μm to 2 μm and / or organic fine particles (B ′) having an average particle size of 0.1 μm to 5 μm. The average particle diameter of the fine particles varies depending on the light diffusion performance required for the optical lens sheet, but the particle diameter is determined by the Coulter counter method.

  In the present invention, it is important that the light condensing function as an original lens is not greatly impaired while having light diffusibility, so that the transparency is not significantly reduced, and when the optical sheet lens is molded. It is important to select the average particle size of the fine particles so that there are no defects in appearance. In order to combine the light diffusibility, the light condensing function as a lens, and the storage stability of the resin composition, the average particle size is preferably 0.1 μm to 2 μm in the case of inorganic fine particles, and the average particle size in the case of organic fine particles. 0.1 μm to 5 μm is preferable. In the case of inorganic fine particles, those finely divided by pulverization or classification are particularly preferred.

  Examples of the inorganic fine particles (B) include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, aluminum oxide, silicon dioxide, titanium dioxide, talc, clay, kaolin, colloidal silica, and metal powder. Examples thereof include inorganic powders and fine particles obtained by surface treatment of these inorganic powders, and inorganic fine particles such as silicon dioxide whose surface is hydrophobized with dimethylpolysiloxane or dimethyldichlorosilane are particularly preferable.

  Examples of the organic fine particles (B ′) include polystyrene resin beads, acrylic resin beads, urethane resin beads, polycarbonate resin beads, resin powder of benzoguanamine-formalin condensate, resin powder of benzoguanamine-melamine-formalin condensate, Examples include resin powder of urea-formalin condensate, powder of aspartate derivative, zinc stearate powder, stearamide powder, epoxy resin powder, polyethylene powder and the like. Cross-linked polymethyl methacrylate resin beads and cross-linked polymethyl methacrylate / styrene resin beads are particularly preferred. These can be easily obtained as commercial products, and can also be prepared with reference to known literature. In the resin composition of the present invention, the inorganic fine particles (B) and the organic fine particles (B ′) may be used singly or as a mixture of plural kinds.

  Further, as a fine particle dispersant, a polycarboxylic acid dispersant, a silane coupling agent, a titanate coupling agent, a silicone dispersant such as a modified silicone oil, or an organic copolymer dispersant may be used in combination. Is possible. As these compounding ratios, it is about 0 to 10% with respect to the total weight of the resin composition of this invention, Preferably it is about 0.05 to 5%.

  Examples of the photopolymerization initiator (C) contained in the resin composition of the present invention include benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, and benzoin isobutyl ether; acetophenone, 2,2-diethoxy- 2-phenylacetophenone, 1,1-dichloroacetophenone, 2-hydroxy-2-methylphenylpropan-1-one, diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl ] Acetophenones such as 2-morpholinopropan-1-one; anthraquinones such as 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-chloroanthraquinone, 2-amylanthraquinone; 2,4-diethyl Thioxanthones such as oxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenone, 4-benzoyl-4′-methyldiphenyl sulfide, 4,4′-bismethyl Benzophenones such as aminobenzophenone; phosphine oxides such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide. Preferred are acetophenones, and more preferred are 2-hydroxy-2-methylphenylpropan-1-one and 1-hydroxycyclohexyl phenyl ketone. In addition, in the resin composition of this invention, a photoinitiator (C) may be used independently and may be used in mixture of multiple types.

  The resin composition of the present invention is a polyfunctional compound having three or more (meth) acryloyl groups in the molecule in consideration of the hardness of the cured product of the obtained resin composition and the glass transition temperature (Tg). A (meth) acrylate monomer (D) can be used.

  Examples of the polyfunctional (meth) acrylate monomer (D) having three or more (meth) acryloyl groups in the molecule include tris (acryloxyethyl) isocyanurate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth). ) Acrylate, dipentaerythritol penta (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tripentaerythritol penta (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane polyethoxytri (meth) acrylate, Examples thereof include ditrimethylolpropane tetra (meth) acrylate.

  In consideration of the viscosity, refractive index, adhesion and the like of the resulting resin composition, the resin composition of the present invention further includes three acrylate monomers (A) having a phenyl ether group and three molecules in the molecule. You may use the (meth) acrylate compound (E) other than the polyfunctional (meth) acrylate monomer (D) which has the above (meth) acryloyl group individually or in mixture of 2 or more types. Examples of the (meth) acrylate compound (E) include monofunctional (meth) acrylate monomers other than the component (A) and the component (D), bifunctional (meth) acrylate monomers, and (meth) acrylate oligomers.

  Examples of the monofunctional (meth) acrylate monomer include acryloylmorpholine, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, cyclohexane-1,4-dimethanol mono (meth) acrylate, and tetrahydrofur Examples include furyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and dicyclopentenyloxyethyl (meth) acrylate.

  Examples of the bifunctional (meth) acrylate monomer include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, Cyclodecane dimethanol di (meth) acrylate, bisphenol A polyethoxydi (meth) acrylate, bisphenol A polypropoxydi (meth) acrylate, bisphenol F polyethoxydi (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) Acrylate, di (meth) acrylate of ε-caprolactone adduct of hydroxybivalate neopentyl glycol (for example, KAYARAD HX-220, HX-620, etc., manufactured by Nippon Kayaku Co., Ltd.) It is.

  Examples of the (meth) acrylate oligomer include urethane (meth) acrylate, epoxy (meth) acrylate, and polyester (meth) acrylate.

  Examples of the urethane (meth) acrylate include diol compounds (for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,4-butanediol, neopentyl glycol, 1,6- Hexanediol, 1,8-octanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentane Diol, 2-butyl-2-ethyl-1,3-propanediol, cyclohexane-1,4-dimethanol, polyethylene glycol, polypropylene glycol, bisphenol A polyethoxydiol, bisphenol A polypropoxydiol ) Or a polyester diol which is a reaction product of these diol compounds with a dibasic acid (for example, succinic acid, adipic acid, azelaic acid, dimer acid, isophthalic acid, terephthalic acid, phthalic acid) or an anhydride thereof, and organic polyisocyanate (For example, chain saturated hydrocarbon isocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, isophorone diisocyanate, norbornane diisocyanate, dicyclohexylmethane diisocyanate , Methylenebis (4-cyclohexylisocyanate), hydrogenated diphenylmethane diisocyanate, hydrogenated xylene diisocyanate, hydrogenated toluene diisocyanate Cyclic saturated hydrocarbon isocyanates such as nates, 2,4-tolylene diisocyanate, 1,3-xylylene diisocyanate, p-phenylene diisocyanate, 3,3′-dimethyl-4,4′-diphenylene diisocyanate, 6-isopropyl- 1,3-phenyl diisocyanate, aromatic polyisocyanate such as 1,5-naphthalene diisocyanate), then 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate The reaction material etc. which added hydroxyl-containing (meth) acrylates, such as, etc. are mentioned.

  Epoxy (meth) acrylates include bisphenol A type epoxy resins, bisphenol F type epoxy resins, phenol novolac type epoxy resins, terminal glycidyl ethers of bisphenol A propylene oxide adducts, fluorene epoxy resins, and (meth) Examples include a reaction product with acrylic acid.

  Examples of the polyester (meth) acrylate include a reaction product of a polyester diol which is a reaction product of the above diol compound and the above dibasic acid or its anhydride, and (meth) acrylic acid.

  The proportion of each component contained in the resin composition of the present invention is determined in consideration of the desired refractive index, glass transition temperature, viscosity, adhesion, light diffusivity, etc., but component (A) + component (D) When the total amount of the + component (E) is 100 parts by weight, the content of the component (A) is 3 to 100 parts by weight, particularly preferably 5 to 100 parts by weight. Content of a component (D) is 0-50 weight part, Most preferably, it is 0-40 weight part. The content of component (E) is 0 to 45 parts by weight.

Component (C) is preferably used in an amount of 0.1 to 10 parts by weight, particularly preferably 0.3 to 5 parts by weight, with the total amount of component (A) + component (D) + component (E) being 100 parts by weight. It is.
The amount of component (B) and / or component (B ′) added depends on the required light diffusion performance, but is 0.1% with respect to 100 parts by weight of the total amount of component (A) + component (D) + component (E). It is preferable to use 10 to 10 parts by weight, and particularly preferably 0.3 to 7 parts by weight.

  In addition to the above components, the resin composition of the present invention includes a release agent, an antifoaming agent, a leveling agent, a light stabilizer, an antioxidant, a polymerization inhibitor, an antistatic agent, in order to improve convenience during handling. An agent or the like can be used in combination depending on the situation. Furthermore, polymers such as acrylic polymers, polyester elastomers, urethane polymers or nitrile rubbers can be added as necessary. Although a solvent can also be added, what does not add a solvent is preferable.

  The resin composition of the present invention can be prepared by mixing and dissolving and dispersing each component according to a conventional method. For example, each component can be prepared in a round bottom flask equipped with a stirrer and a thermometer and stirred at 40 to 80 ° C. for 0.5 to 6 hours. Further, if necessary, the inorganic fine particles (B) and / or the organic fine particles (B ′) may be dispersed by a known dispersing machine such as a ball mill, a roll mill, a sand mill, or a dissolver to prepare the resin composition of the present invention. Good.

  The viscosity of the resin composition of the present invention is determined using an E-type viscometer (TV-200: manufactured by Toki Sangyo Co., Ltd.) in terms of transferability of the shape when manufacturing optical lens sheets and workability during processing. A composition having a viscosity measured in the range of 50 mPa · s to 4000 mPa · s at 25 ° C. is preferred.

  A cured product obtained by curing the resin composition of the present invention by irradiating energy rays such as ultraviolet rays according to a conventional method is also included in the present invention. For example, the cured product is obtained by applying the resin composition of the present invention on a stamper having a shape such as a Fresnel lens, a lenticular lens, or a prism lens to provide a layer of the resin composition, and a hard transparent substrate on the layer. A back sheet (for example, a substrate or film made of polymethacrylic resin, polycarbonate resin, polystyrene resin, polyester resin, or a blend of these polymers) is adhered, and then ultraviolet light is emitted from the hard transparent substrate side by a high-pressure mercury lamp or the like. After the resin composition is cured by irradiation, the cured product can be peeled off from the stamper. Moreover, it can also carry out by a continuous process as these applications.

  In this way, optical lens parts such as Fresnel lenses, lenticular lenses, prism lenses, and micro lenses having a refractive index (25 ° C.) of 1.55 or more and excellent in releasability, mold reproducibility, adhesion, and light resistance are formed. Optical lens sheets can be obtained, and these are also included in the present invention. The refractive index can be measured with an Abbe refractometer (model number: DR-M2, manufactured by Atago Co., Ltd.).

  The resin composition of the present invention is useful as an optical lens sheet, for example, as a Fresnel lens, a lenticular lens, a prism lens, a microlens, or the like. Moreover, various coating agents, adhesives, etc. are mentioned as uses other than for optical lens sheets.

  Next, the present invention will be described in more detail with reference to examples. In addition, this invention is not limited at all by the following examples.

  The ultraviolet curable resin composition of the present invention and the cured film thereof were obtained with the compositions as shown in the following examples (numerical values indicate parts by weight). The evaluation method and evaluation criteria were as follows.

(1) Releasability: Expresses the degree of difficulty when releasing a cured resin from a mold.
○ ····························································································································· Mold reproducibility: The surface shape of the cured ultraviolet curable resin layer and the surface shape of the mold were observed.
○ ···· Reproducibility is good × ··· Reproducibility is poor

(3) Storage stability: The state of the liquid when the resin composition was allowed to stand at room temperature for 1 month was visually evaluated.
○ ··· Stable without separation or sedimentation × ··· Separation or sedimentation is confirmed (4) Adhesiveness: A resin composition is applied on a substrate to a film thickness of about 40 μm, and then high pressure A test piece was cured by irradiation with 1000 mJ / cm ^{2 with} a mercury lamp (80 W / cm, ozone-less), and the adhesion was evaluated according to JIS K5600-5-6.
In the evaluation results, 0 to 2 were evaluated as ○, and 3 to 5 as ×.

(5) Refractive index (25 ° C.): The refractive index (25 ° C.) of the cured ultraviolet curable resin layer was measured with an Abbe refractometer (DR-M2: manufactured by Atago Co., Ltd.).
(6) Glass transition point temperature (Tg): The glass transition point temperature of the cured UV curable resin layer is determined by using a viscoelasticity measurement system (DMS-6000: manufactured by Seiko Denshi Kogyo Co., Ltd.) in a tensile mode at a frequency of 1 Hz. It was measured.
(7) Transmittance, haze measurement: Haze meter TC-HIIIDPK (manufactured by Tokyo Denshoku Co., Ltd.) was used to determine the transmittance and haze of a sample prepared by evaluation of adhesion and having a resin composition coated on a substrate to a thickness of about 40 μm Measured with

Synthetic synthesis example 1 of urethane (meth) acrylate
In a dry container, 94.7 parts of o-phenylphenol monoethoxyacrylate and 139.3 parts of 2,4-tolylene diisocyanate were charged, and bisphenol A poly (n = 2) propoxydiol (hydroxyl value 312 mgKOH / g) 143. Nine parts were charged in three portions while confirming the exotherm, stirred at 80 ° C., and reacted for about 10 hours. When the NCO value (referred to as urethane value, expressed by weight% of the remaining isocyanate group based on the total reaction product) of 11.9% by weight measured according to the standard method was 95.7%, 2-hydroxyethyl acrylate 95.7% 1 part, 0.2 parts of p-methoxyphenol and 0.06 part of di-n-butyltin dilaurate were added, the reaction was carried out at 80 ° C. for about 12 hours, and the reaction was carried out when the NCO value was 0.1% by weight or less. finished.

Example 1
As component (A), 51 parts of o-phenylphenol monoethoxy acrylate, 5 parts of phenyloxyethyl acrylate, 25 parts of dipentaerythritol hexaacrylate as component (D), urethane acrylate 19 obtained in Synthesis Example 1 as component (E) As a component, component (C), 3 parts of 1-hydroxycyclohexyl phenyl ketone was heated to 60 ° C., mixed and dissolved. Furthermore, as a component (B), 2 parts of hydrophobic silica having an average particle diameter of 1.2 μm in a Coulter counter were mixed and dispersed while stirring to obtain a resin composition of the present invention. The film obtained by curing the resin composition had a refractive index (25 ° C.) of 1.576, a glass transition temperature (Tg) of 70 ° C., a transmittance of 91%, and a haze value of 11%.
This resin composition is applied onto a prism lens mold so as to have a film thickness of 50 μm, and an easy-adhesion-treated polyester film (100 μm thickness) is adhered thereon as a base material. After being cured by irradiating with an ultraviolet ray of 1000 mJ / cm ² , it was peeled off to obtain a prism lens sheet.
Evaluation results: releasability: ○, mold reproducibility: ○, storage stability: ○, adhesion: ○.

Example 2
In Example 1, in place of 2 parts of hydrophobic silica having an average particle diameter of 1.2 μm as fine particles, 2 parts of crosslinked polymethyl methacrylate fine particles having an average particle diameter of 2.2 μm were used in a Coulter counter in the same manner as in Example 1. Thus, the resin composition of the present invention was obtained. The film obtained by curing the resin composition had a refractive index (25 ° C.) of 1.577, a glass transition temperature (Tg) of 70 ° C., a transmittance of 94%, and a haze value of 37%.
This resin composition is applied onto a prism lens mold so as to have a film thickness of 50 μm, and an easy-adhesion-treated polyester film (100 μm thickness) is adhered thereon as a base material. After being cured by irradiating with an ultraviolet ray of 1000 mJ / cm ² , it was peeled off to obtain a prism lens sheet.
Evaluation results: releasability: ○, mold reproducibility: ○, storage stability: ○, adhesion: ○.

Comparative Example 1
In Example 1, in place of 2 parts of hydrophobic silica having an average particle diameter of 1.2 μm as fine particles, 2 parts of hydrophobic silica having an average particle diameter of 3 μm in a Coulter counter is used in the same manner as in Example 1, and the present invention. A resin composition was obtained. The film obtained by curing the resin composition had a refractive index (25 ° C.) of 1.576, a glass transition temperature (Tg) of 70 ° C., a transmittance of 89%, and a haze value of 13%.
This resin composition is applied onto a prism lens mold so as to have a film thickness of 50 μm, and an easy-adhesion-treated polyester film (100 μm thickness) is adhered thereon as a base material. After being cured by irradiating with an ultraviolet ray of 1000 mJ / cm ² , it was peeled off to obtain a prism lens sheet.
Evaluation results: releasability: ○, mold reproducibility: ○, storage stability: ×, adhesion: ○.

Comparative Example 2
In Example 1, instead of 2 parts of hydrophobic silica having an average particle diameter of 1.2 μm as fine particles, 2 parts of crosslinked acrylic beads (polymethyl methacrylate / styrene) having an average particle diameter of 6 μm in a Coulter counter were used. In the same manner as in Example 1, a comparative resin composition was obtained. This resin composition is applied onto a prism lens mold so as to have a film thickness of 50 μm, and an easy-adhesion-treated polyester film (100 μm thickness) is adhered thereon as a base material. After being cured by irradiating with an ultraviolet ray of 1000 mJ / cm ² , it was peeled off to obtain a prism lens sheet. The obtained sheet had a non-uniform appearance and a non-uniform light transmission state, which was inappropriate as a lens sheet. The releasability was ○, but the storage stability was ×.

  As is clear from the evaluation results of Examples 1 and 2 and Comparative Examples 1 and 2, the resin composition of the present invention has good storage stability, excellent releasability, mold reproducibility, and adhesion to a substrate. The cured product had a high refractive index and a glass transition temperature (Tg) of 50 ° C. or higher. Therefore, it is suitable for an optical lens sheet having a fine structure, such as a Fresnel lens, a lenticular lens, a prism lens, and a microlens. Since the haze that is an index of light diffusivity can be arbitrarily adjusted while maintaining the refractive index and transmittance, it is possible to simultaneously impart a desired light collecting function and light diffusing function on the lens molding surface.

Claims (8)

Monoacrylate monomer (A) having a phenyl ether group, inorganic fine particles (B) having an average particle size of 0.1 to 2 μm and / or organic fine particles (B ′) having an average particle size of 0.1 to 5 μm, and photopolymerization An energy ray-curable resin composition for an optical lens sheet, comprising an initiator (C). The resin composition according to claim 1, wherein the monoacrylate monomer (A) having a phenyl ether group is o-phenylphenol polyethoxy (meth) acrylate. The resin composition according to claim 1 or 2, wherein the inorganic fine particles (B) are inorganic fine particles having a hydrophobic surface. Furthermore, the resin composition as described in any one of Claim 1 thru | or 3 containing the polyfunctional (meth) acrylate monomer (D) which has a 3 or more (meth) acryloyl group in a molecule | numerator. Further, it includes a (meth) acrylate compound (E) other than a monoacrylate monomer (A) having a phenyl ether group and a polyfunctional (meth) acrylate monomer (D) having three or more (meth) acryloyl groups in the molecule. The resin composition as described in any one of Claims 1 thru | or 4. Hardened | cured material whose refractive index in 25 degreeC obtained by hardening | curing the resin composition as described in any one of Claims 1 thru | or 5 is 1.55 or more. Hardened | cured material which provided the lens shape by shape | molding the resin composition as described in any one of Claim 1 thru | or 5 on a base film. An optical lens sheet using the cured product according to claim 6 or 7.