JP3077952B2 - UV curable resin composition for transmission screen and cured product thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a video projector,
The present invention relates to a UV-curable resin composition suitable for a transmission screen such as a Fresnel lens or a lenticular lens used for a projection television or the like, and a cured product thereof.

[0002]

2. Description of the Related Art Heretofore, this kind of lens has been formed by a method such as a press method or a cast method. The former press method has poor productivity because it is manufactured by a cycle of heating, pressing and cooling. In addition, the latter casting method requires a long production time because a monomer is poured into a mold and is polymerized, and requires a large number of molds. Recently, a lens mold and a transparent resin base material (eg, polycarbonate, PVC, polyester) have been used. , Acrylic, styrene, etc.), and various methods have been proposed in which an ultraviolet-curable resin liquid for forming a lens portion is interposed between the lens portions and an ultraviolet ray is applied to cure the lens portion integrally.
(For example, Japanese Patent Application Laid-Open Nos. 61-177215 and 61-2
48707, JP-A-61-248708, JP-A-63-248
163330, JP-A-63-167301, JP-A-63-163301
199302, JP-A-64-6935, etc.)

[0003]

In the technique of forming a lens portion by interposing an ultraviolet curable resin between a lens mold and a transparent resin substrate, there is not enough space between the lens portion and the transparent resin substrate. In many cases, adhesion cannot be obtained. In particular, when a resin containing methacrylic resin, which is excellent in transparency and weather resistance and is suitable as this kind of material, is used as a base material, the adhesiveness with an ultraviolet-curable resin is insufficient, so that the adhesiveness is low. Is strongly desired. In addition, no proposal has been made to meet the demand for thinner projection televisions and the like.

[0004]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have made intensive studies and found that curing by ultraviolet rays is fast, and that the resin has excellent adhesion to a resin base material, especially methacrylic resin, and that the curing thereof The present inventors have found a resin composition having a high refractive index and completed the present invention. That is, the present invention provides a molecular weight of 1
20 to 50% by weight of a bisphenol A type epoxy (meth) acrylate (A) of 000 or more, a monofunctional reactive monomer (however, (R excluding H or CH ₃ ) (B) 40 to 70% by weight of a bifunctional reactive monomer (however,
(Except for a complex obtained by dissolving at least one of an alkali metal salt or an alkaline earth metal salt and a protonic acid in (meth) acrylate) (C) 5 to 25% by weight and photopolymerization initiator (D) 0.5 The present invention relates to an ultraviolet-curable resin composition for a transmission screen characterized by containing from 10 to 10% by weight.

Bisphenol A type epoxy (meth) acrylate (A) having a molecular weight of 1,000 or more used in the present invention
Specific examples of the epoxy resin include, for example, bisphenol A type epoxy resin (eg, manufactured by Yuka Shell Epoxy Co., Ltd., Epicoat 1001 (epoxy equivalent 450 to 500), Epicoat 1003 (epoxy equivalent 670 to 770), Epicoat 1004 (epoxy equivalent) 875-975). It can be obtained by reacting｝ with (meth) acrylic acid. Reacting (meth) acrylic acid in a ratio of preferably about 0.7 to 1.5 equivalents, particularly preferably about 0.9 to 1.1 equivalents, per equivalent of epoxy group of the bisphenol A type epoxy resin, Monofunctional reactive monomer (B) as a diluent at the time of reaction {for example, dicyclopentadieneoxyethyl (meth) acrylate (manufactured by Hitachi Chemical Co., Ltd., FA-512A, FA-5)
12M) tetrahydrofurfuryl (meth) acrylate, carbitol (meth) acrylate, phenoxyethyl (meth) acrylate, phenylpolyethoxy (meth) acrylate, isobornyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, phenylglycidyl ether (Meth) acrylate, N-
Vinylcaprolactam, acryloylmorpholine, polyethoxy (meth) acrylate of 0-phenylphenol, polyethoxy (meth) acrylate of p-phenylphenol, o-phenylphenoxyethyl (meth) acrylate, tribromophenoxyethyl (meth) acrylate, tribromo Bromobenzyl (meth) acrylate,
It is preferred to use an equality. In order to promote the reaction, it is preferable to use a catalyst (for example, triethylamine, benzyldimethylamine, methyltriethylammonium chloride, triphenylstibine, triphenylphosphine, etc.). Is preferably used in the range of 0.1 to 10% by weight. In order to prevent polymerization during the reaction, it is preferable to use a polymerization inhibitor (for example, methoquinone, hydroquinone, phenothiazine, etc.), and the amount used is in the range of 0.01 to 1% by weight based on the reaction raw material mixture. Is preferred. The reaction temperature is 60 to 150 ° C, and the reaction time is usually 5 to 60 hours.

[0006] In the resin composition of the present invention, the amount of the component (A) is from 20 to 50% by weight, preferably from 20 to 40% by weight. If it is used in an amount of 50% by weight or more, the viscosity of the resin composition increases, and the coatability deteriorates.
When the content is 20% by weight or less, the adhesion to the methacrylic resin substrate deteriorates, and the refractive index of the resin composition also decreases.

Specific examples of the monofunctional reactive monomer (B) are as described above, and particularly preferred are acrylates of phenylglycidyl ether (KAYARAD R-128H, manufactured by Nippon Kayaku Co., Ltd.). ), Phenoxyethyl acrylate, phenylpolyethoxyacrylate (n =
1-4), dicyclopentadieneoxyethyl acrylate, o-phenylphenol poly (n = 1 to 4) ethoxy acrylate, and tribromophenyloxyethyl acrylate having a high refractive index.

[0008] In the resin composition of the present invention, the amount of the component (B) is from 40 to 70% by weight, preferably from 40 to 60% by weight. If it is used in an amount of 70% by weight or more, the releasability, restorability, and abrasion resistance of a cured product of the resin composition deteriorate, and if it is 40% by weight or less, the adhesion to a methacrylic resin substrate deteriorates.

Specific examples of the bifunctional reactive monomer (C) include, for example, polyethoxydi (meth)
Acrylate, polyethoxydi (meth) acrylate of bisphenol F, polyethoxydi (meth) acrylate of tetrabromobisphenol A, di (meth) acrylate of ε-caprolactone adduct of neopentyl glycol hydroxypivalate, 1,6-hexanediol di (meth) A) acrylate, 1,9-nonanediol (meth) acrylate, polyethylene glycol di (meth) acrylate, and the like. Particularly preferred are those having a high refractive index such as bisphenol A tetraethoxydiacrylate and bisphenol A poly (n = 9 to 15) ethoxydiacrylate.

In the resin composition of the present invention, the amount of the component (C) is 5 to 30% by weight, preferably 5 to 25% by weight. If it is used in an amount of 30% by weight or more, the adhesion to the methacrylic resin substrate is deteriorated, and if it is 5% by weight or less, the resilience and abrasion resistance of a cured product of the resin composition are deteriorated.

The photopolymerization initiator (D) includes, for example,

[0012]

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[0013]

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[0014]

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[0015]

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And a copolymerizable photopolymerization initiator, benzoin,
Benzyl, benzoin methyl ether, benzoin isopropyl ether, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2- Methyl-1- [4- (methylthio) phenyl) -2-morpholinopropan-1-one, N, N
-Dimethylaminoacetophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2-aminoanthraquinone, 2,4
-Dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, acetophenone dimethyl ketal, benzophenone, methylbenzophenone, 4,4'-dichlorobenzophenone,
4,4'-bisdiethylaminobenzophenone, Michler's ketone and the like can be mentioned. These can be used alone or in combination of two or more. Further, such a photopolymerization initiator (D) may be a known and commonly used photosensitizer such as ethyl N, N-dimethylaminobenzoate, isoamyl N, N-dimethylaminobenzoate, triethanolamine and triethylamine. Alone or 2
More than one species can be used in combination.

In the resin composition of the present invention, the amount of the component (D) is 0.5 to 10% by weight, preferably 1 to 7% by weight. Even when used in an amount of 10% by weight or more, the curability is not significantly improved. 0.5% by weight
In the following cases, the curability is not sufficient.

The resin composition of the present invention comprises (A), (B),
It can be obtained by dissolving and mixing the components (C) and (D). The resin composition of the present invention may further comprise, in addition to the above components, urethane (meth) acrylates (e.g., ethylene glycol, 1,4-butanediol, neopentyl glycol, polycaprolactone polyol, polyester polyol, polycarbonate diol, polytetramethylene glycol, and the like). Polyols and hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, xylylene diisocyanate, 4,
Organic polyisocyanates such as 4'-diphenylmethane diisocyanate and ε- of 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and 2-hydroxyethyl (meth) acrylate
Reactants of hydroxyl group-containing ethylenically unsaturated compounds such as caprolactone adducts can be mentioned. ) Or a tri- or higher functional reactive monomer can be used if necessary. Further, a release agent, an antifoaming agent, a leveling agent, a light stabilizer (for example, hindered amine), an antioxidant, a flame retardant, an ultraviolet absorber, a polymerization inhibitor, an antistatic agent, and the like can be used in combination.

The cured product of the resin composition of the present invention can be obtained by irradiating the resin composition of the present invention with ultraviolet rays according to a conventional method. Specifically, the ultraviolet curable resin composition for a transmission screen of the present invention is applied, for example, on a stamper having the shape of a Fresnel lens or a lenticular lens, and a layer of the ultraviolet curable resin composition is provided. Then, a transparent resin substrate is adhered on the substrate, and in this state, the resin composition is cured by irradiating ultraviolet rays from the transparent resin substrate side with a high-pressure mercury lamp or the like, and then peeled from the stamper. Thus, the ordinary refractive index (23 ° C.) is 1.55
As described above, under preferable conditions, a transmission screen such as a Fresnel lens or a lenticular lens having 1.56 or more can be obtained.

[0020]

Next, the present invention will be described more specifically with reference to examples. The evaluation in the examples was performed by the following method. (1) Releasability: Difficulty in releasing the cured resin from the mold ○: Good releasability from the mold △: Slightly difficult to release ×: Release (2) Mold reproducibility: The surface shape of the cured ultraviolet curable resin layer and the surface shape of the mold were observed. ○: good reproducibility ×: poor reproducibility (3) Adhesion: UV-curable resin composition on transparent methacryl substrate is 200 μm thick, 20 mm wide and 150 m long
m, then high-pressure mercury lamp (80w / cm, ozone-less)
Irradiation of 500 mj / cm ² was carried out for curing to prepare a test piece, and the peel strength was measured. (Measurement method of peel strength: 90 ° peel strength of the cured resin film on the methacrylic substrate was measured by a tensile tester. (Peeling speed 100 mm /
Min) ◎ ・ ・ ・ ・ Peel strength 2kg / cm or more ○ ・ ・ ・ ・ Peel strength 1-2kg / cm △ ・ ・ ・ ・ Peel strength 0.5-1kg / cm × ・ ・ ・ ・ Peel strength 0.5kg / cm or less

(4) Restorability: After strongly pressing a metal round bar having a diameter of 10 mm against the surface of the cured ultraviolet curable resin layer released from the mold, until the trace of the round bar on the surface completely disappears. Was measured. ◎: Disappeared instantaneously ・ ・ ・: Disappeared within 60 seconds △: Disappeared in 1 to 60 minutes ×: Not disappeared (5) Scratch resistance: cured A methacrylic resin plate (width 100 mm, length 100 mm, thickness 2.5 mm) is strongly pressed vertically against the surface of the ultraviolet curable resin layer released from the mold at a speed of about 1 second per round trip at intervals of about 100 mm. 10
After reciprocating, the surface was observed for scratches. ◎ ・ ・ ・ ・ ・ ・ No scratches are recognized ○ ・ ・ ・ ・ Several stripe-shaped scratches are recognized △ ・ ・ ・ ・ Some band-shaped scratches are recognized × ・ ・ ・ ・ Strip-shaped scratches are entirely formed (6) Refractive index (25 ° C): Measure the refractive index (25 ° C) of the cured ultraviolet curable resin layer

Examples 1 to 4 and Comparative Examples 1 to 4 An ultraviolet-curable resin composition having a composition as shown in Table 1 (the numerical values indicate parts by weight) was used in a Fresnel lens mold having a thickness of 2.5 m.
m, and the mixture was injected with an ultraviolet ray and cured by a conventional method to obtain a Fresnel lens.

[0023]

[Table 1] Example Comparative example 1 2 3 4 1 2 3 4 EP-1004AA * 1 20 30 40 20 30 20 KAYARAD R-114 * 2 40 Urethane acrylate * 3 10 30 KAYARAD R-128H * 4 20 20 20 10 10 10 20 KAYARAD R-561 * 5 10 15 15 10 KAYARAD R-564 * 6 10 20 10 20 KAYARAD OPP-2 * 7 20 10 10 30 20 20 FA-512A * 8 5 10 Tribromophenyloxyethyl acrylate 10 10 10 10 10 10 10 KAYARAD R-551 * 9 10 10 20 BPE-10 * 10 20 15 5 15 10 20 20 Irgacure 184 * 11 3 3 3 3 3 3 3 3 LA-82 * 12 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 SH-3749 * 13 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Physical properties of liquid Viscosity (25 ° C) CPS 3800 5630 7900 6210 6520 5120 6350 2100 Refractive index (25 ° C) 1,552 1,551 1,552 1,551 1,550 1,552 1,552 1,553 Physical properties Releasability ○ ○ ○ ○ ○ ○ ○ × Adhesion ◎ ○ ◎ ○ × × × ◎ Mold reproducibility ○ ○ ○ ○ ○ ○ ○ ○ Restorability ○ ◎ ○ ◎ ○ ◎ ◎ △ Scratch resistance ◎ ◎ ◎ ◎ ◎ △ × ◎ × Refractive index (25 ℃) 1 , 572 1,571 1,573 1,571 1,570 1,573 1,572 1,573

* 1 EP-1004AA: Bisphenol A type epoxy acrylate having a molecular weight of 1000 or more obtained by reacting bisphenol A type epoxy resin (Eicoat 1004, epoxy equivalent: 900, manufactured by Yuka Shell Epoxy Co., Ltd.) with acrylic acid * 2 KAYARAD R-114: Bisphenol A type epoxy resin manufactured by Nippon Kayaku Co., Ltd. (Yukaka Epoxy Co., Ltd.)
Urethane acrylate: Kurapole P-1010 manufactured by Kuraray Co., Ltd., Kuraray Co., Ltd., molecular weight 1000) 2.05 mol of a reaction product of 1 mol and 2 mol of tolylene diisothenate -Urethane acrylate reacted with hydroxyethyl acrylate * 4 KAYARAD R-128H: Nippon Kayaku Co., Ltd., acrylate of phenylglycidyl ether * 5 KAYARAD R-561: Nippon Kayaku Co., Ltd., phenoxyethyl acrylate

* 6 KAYARAD R-564: Nippon Kayaku Co., Ltd.
* 7 KAYARAD OPP-2: Nippon Kayaku Co., Ltd., polyethoxy acrylate of o-phenylphenol * 8 FA-512A: Hitachi Chemical Co., Ltd., dicyclopentadiene oxyethyl acrylate * 9 KAYARAD R-551: Nippon Kayaku Co., Ltd., bisphenol A tetraethoxy diacrylate * 10 BPE-10: bisphenol A polyethoxy diacrylate (average of n is 10) * 11 Irgacure 184: manufactured by Ciba Geigy, Photopolymerization initiator * 12 LA-82: Asahi Denka Co., Ltd., light stabilizer * 13 SH-3749: Shin-Etsu Silicone Co., Ltd., leveling agent

As is evident from Table 1, the cured product of the resin composition of the present invention has a releasability, mold reproducibility, adhesiveness, resilience,
Excellent scratch resistance and high refractive index of 1.57 or more.

[0027]

The cured product of the resin composition of the present invention has a high refractive index, excellent adhesion to a substrate, mold releasability, mold reproducibility,
Excellent resilience and scratch resistance, suitable for transmission screens.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08F 290/00-290/14 C08F 2/00-2/60 G02B 1/04 G03B 21/62

Claims (1)

(57) [Claims] 1. A bisphenol A type epoxy (meth) acrylate (A) having a molecular weight of 1,000 or more, 20 to 50% by weight, a monofunctional reactive monomer (provided that the formula (R excluding H or CH ₃ ) (B) 40 to 70% by weight of a bifunctional reactive monomer (however,
(Excluding a complex obtained by dissolving at least one of an alkali metal salt, an alkaline earth metal salt, and a protonic acid in (meth) acrylate) (C) 5 to 25% by weight and photopolymerization initiator (D) 0.5 to An ultraviolet curable resin composition for a transmission screen, comprising 10% by weight.