JPS61221210A - Ultraviolet-curable resin composition and disk material - Google Patents

Abstract

PURPOSE:An ultraviolet-curable resin composition useful as a substrate of an optical disk recording medium and low in the water absorption of a cured product, obtained by mixing a compound of a specified structure with an ethylenically unsaturated group-containing compound and a photosensitizer as optional components. CONSTITUTION:A compound (A) of formula I or II (wherein R1 and R2 are each H or CH3) is mixed with a compound (B) having at least one ethylenically unsaturated groups in the molecule and a photosensitizer (C) as optional components. The compound of formula I can be obtained by esterifying 2- hydroxydecalin obtained by hydrogenating beta-naphthol with methcarylic acid. The compound of formula II can be obtained by esterifying hydrogenated bisphenol A obtained by hydrogenating bisphenol A with (meth)acrylic acid. As component B, a low-MW monomer [(meth)acrylic monomers] or a high-MW unsaturated group-containing resin [e.g., epoxy (meth)acrylate] is used.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an ultraviolet curable resin composition, which is particularly useful as a substrate for optical disk recording media that records and reproduces optical signals at high speed and high density. The present invention relates to an ultraviolet curable resin composition and a disk material that harden and have low water absorption.

(Prior Art) Currently, inorganic glass and methyl methacrylate resin are used as disk materials.

Further, a disk material made of monomers such as 2,2-bis(4-(meth)acryloyloxyphenyl)propane and styrene has also been proposed.

(Problems to be Solved by the Invention) However, in the case of glass, there are drawbacks such as heavy responsibility, easy breakage, and high precision processing of glass. On the other hand, in the case of methyl methacrylate resin, although it has advantages such as being hard to break and being cheap, it is more easily scratched than glass, the recording film is more likely to be damaged due to water absorption by the resin, and the disk is more likely to warp. Furthermore, it is difficult to remove -r-mi etc. from the methyl methacrylate resin, and if a disk is molded with dust etc. still inside, there is a drawback that malfunctions occur during recording and reproduction. In order to improve these drawbacks, a disc material made of monomers such as 2,2-bis(4-(meth)acryloyloxyethoxyphenyl)propane and styrene (Japanese Patent Application Laid-open No. 129008/1982) is as follows. Although improvements have been made in terms of water absorption and warpage, the composition still uses styrene, methyl methacrylate, and other substances with a strong odor, and requires long-term curing with peracids, making it difficult to put into practical use. I don't like it from a practical standpoint.

(Means for Solving the Problems) In order to solve the above problems, the inventors of the present invention have conducted intensive research and found that they cure quickly with ultraviolet rays, do not require the use of strong odor materials such as styrene, and absorb water. We have succeeded in providing an ultraviolet curable resin composition with a low UV curability. That is, the present invention provides a) one or more compounds selected from the compounds represented by the following general formula (I) or (fI) (wherein Rt is H or CH3) 0 [ ■] o-C-C=CH2 (in the formula, R2 is H or C) (3) b) A compound (B) having one or more ethylenically unsaturated groups in the molecule as an optional component; C) A photosensitizer (compound Q).
3) and an ultraviolet curable disk material characterized by containing 0 photosensitizer.

The compound represented by the general formula [■] used in the present invention is 2 obtained by hydrogenating β-naphthol.
- It can be obtained from K by subjecting hydroxy decalin and (meth)acrylic acid to an esterification reaction.

Further, the compound represented by the general formula (II) can be obtained by subjecting hydrogenated bisphenol A obtained by hydrogenating bisphenol A to an esterification reaction with (meth)acrylic acid. A specific method for producing the compound represented by the general formula CI) or (ff) is as follows.

1 mol of 2-hydroxy decalin or 0.5 mol of hydrogenated bisphenol A, 1.0 to 2.0 mol of (meth)acrylic acid
mol preferably 1.1 to 1.5 mol,
For example, add 0.01 to 5% by weight of (meth)acrylic acid and hydroquinone (p-)luenesulfonic acid), heat to 70°C to 130°C, dehydrate, wash with caustic, and wash with water to remove low boiling point substances. By removing K, a compound represented by general formula (T) or general formula (n) is obtained.

In the present invention, the compound (B) having one or more ethylenically unsaturated groups in the molecule is an optional component, and may be used if necessary. In order to reduce the water absorption rate, it is preferable to have as little hydrophilicity as possible, and they can be broadly divided into low molecular monomers and polymeric unsaturated group-containing resins. Specific examples of the low molecular monomer include dicyclopentadiene ethoxy mono(meth)acrylate, inbornyl(meth)acrylate, hydrogenated dicyclopentadiene mono(meth)acrylate, 2,2-bis(4 - (meta)
acryloyloxyethoxyphenyl)propane, 2.
(meth)acrylates such as 2-bis(4-(meth)acryloyloxyethoxyphenyl)methane, 2.2-bis(4-(meth)acryloyloxypropoxyphenyl)propane, and trimethylolpropane tri(methacrylate) Specific examples of the polymeric unsaturated group-containing resin include bisphenol A
Epoxy (meth)acrylate obtained by the reaction of epoxy resin such as type epoxy resin or novolac type epoxy resin with (meth)acrylic acid, polybasic acid such as cono-phosphoric anhydride and polyhydric alcohol such as trimethylolpropane. Examples include polyester (meth)acrylate obtained by reacting polyester obtained by reaction with (meth)acrylic acid, urethane (meth)acrylate, and the like.

These compounds having one or more ethylenically unsaturated groups in the molecule can be used alone or in combination of two or more. As the photosensitizer (Q), any known photosensitizer can be used, but one with good storage stability after blending is desirable.

Examples of such photosensitizers include benzoin alkyl ethers such as benzoin ethyl ether and penzoin isobutyl ether, 2.2-jetoxyacetophenone, 4-phenoxy-2,2-dichloroacetophenone, and the like. acetophenone, 2-hydroxy-
2-methylpropiophenone, 4'-isopropyl-2
- Propiophenone series such as hydroxy-2-methylpropiophenone, benzyl dimethyl ketal, 1-hydroxycyclohexylphenyl ketone and 2-ethylanthraquinone, anthroquinone series such as 2-chloroanthraquinone, 2-chlorothioxanthone, Examples include thioxanthone photosensitizers such as 2,4-dimethylthioxanthone. These photosensitizers can be used alone or in a mixture of two or more in any proportion. The amount of component (4) used in the composition of the present invention is preferably 40 to 99% by weight, particularly preferably 45 to 75% by weight of the composition. If the amount of the four components is less than 40% by weight, the water absorption rate will be somewhat high, which is not very preferable.

The amount of component Q3) is preferably 0 to 60%, particularly preferably 20 to 40% by weight of the composition. ■)
If the amount of the component exceeds 60% by weight, the water absorption rate will be somewhat high, which is not very preferable.

(The amount of Q component is preferably 0.5 to 15% of the composition.
% by weight, fF is preferably 1 to 5% by weight.

Curing of the composition of the present invention by ultraviolet irradiation can be carried out by a conventional method. For example, ultraviolet rays may be irradiated using a low-pressure or high-pressure mercury lamp, a xenon lamp, or the like.

The composition obtained by curing the composition of the present invention is particularly suitable for optical discs (digital audio discs).

It is useful as a substrate for video discs, memory discs, etc.). In addition, the composition of the present invention is also useful for sealing integrated circuits and the like.

(Example) Hereinafter, the present invention will be specifically explained using manufacturing examples and examples. Note that parts in the production examples and examples are parts by weight.

Production example of compound (a) of general formula CI) and (III) Production example 1. [Production example of compound of general formula CD] 21 reactor equipped with a stirrer, temperature control device, thermometer, condenser and separator , 2-hydroxy decalin (β-naphthol hydride) 666.5 parts, acrylic acid 372 parts, sulfuric acid 11.
2 parts of hydroquinone, 2.8 parts of hydroquinone, 640 parts of benzene, and 160 parts of cyclohexane are charged and heated. The produced water is exhausted together with the solvent, condensed, and only the water is removed from the system in a separator. Return to Cooling occurred when 77.4 parts of water had been produced. The reaction temperature was 82-87°C.

The reaction mixture was mixed with 1120 parts of benzene and 2 parts of cyclohexane.
After dissolving in 80 parts and neutralizing with 20% NaOH aqueous solution, 2
Wash three times with 400 parts of 0% NaCl aqueous solution. The solvent was distilled off under reduced pressure to obtain 709 parts of liquid. This material has the following properties.

Specific gravity (25℃) 1.012 Viscosity (25℃) 11.1 cps Saponification value
256.5 ■KOH/g acid value
0.02 ■KOH/g cracking example 2. Production Example of Compound of General Formula (III) Into the same reactor as in Production Example 1, 496 parts of hydrogenated bisphenol A (manufactured by Shin Nippon Rika Corporation, Ricapinol HB), 346 parts of acrylic acid, and 1 part of sulfuric acid were added.
1.4 parts of hydroquinone, 3.5 parts of hydroquinone, 480 parts of benzene, and 120 parts of cyclohexane, and the reaction was carried out in the same manner as in Production Example 1 until the amount of water produced was 72 parts. reaction mixture,
Dissolved in 360 parts of benzene and 90 parts of cyclohexane,
After neutralizing with a 0% NaOH aqueous solution, it is washed three times with 400 parts of a 20% NaCl aqueous solution. The solvent was distilled off under reduced pressure to obtain 612 parts of a pale yellow waxy substance. This material has the following properties.

Saponification value 312.1 mgKOH/g acid value
0.02 mgKOH/g Example 1゜60 parts of the compound (A) obtained in Production Example 1, epoxy acrylate [obtained by esterifying Epicote 828 (manufactured by Shell Petrochemical Co., Ltd., bisphenol type poxy resin) with acrylic acid. Resin] (B) 40 parts, Irgacure 184 (
Ciba Geigy Co., Ltd. 1j1) (C) Mix 3 parts, inject into a glass mold consisting of a gasket and two glass flat plates, and apply ultraviolet rays from both sides for 5 seconds using a high-pressure mercury lamp (Toshiba Co., Ltd., 2KS%f). Irradiated and cured. Thereafter, the mold was released to obtain a disk substrate with a thickness of 1.5 mm and a diameter of 15 cm. The water absorption rate of the obtained substrate was 0.1%, and the hardness was 80 at 5 hare f. Water absorption rate: The disk was left in hot water at 40° C. for 20 days, and the water absorption rate of the disk was measured from the difference in weight before and after that.

Hardness: The hardness of the disk was measured using a 5hole D hardness meter.

Example 2゜70 parts of the compound (A) obtained in Production Example 2, epoxy acrylate [resin obtained by esterifying Epicote 828 (manufactured by Shell Petrochemical Co., Ltd., bisphenol type epoxy resin) with acrylic acid] (B) 30 copies.

Irgacure-184 (03 parts) was mixed and irradiated with ultraviolet rays from both sides for 2.5 seconds in the same manner as in Example 1 to obtain a disk substrate.The obtained substrate was evaluated in the same manner as in Example 1.The water absorption rate was 0.2%, and the hardness was 91 at 5horeD.

Example 3 50 parts of the compound (A) obtained in Production Example 1, 50 parts of the compound (A) obtained in Production Example 2, and 3 parts of Irgacure-184 (C) were mixed and exposed to ultraviolet light in the same manner as in Example 1. was irradiated for 10 seconds to obtain a disk substrate. The obtained substrate was evaluated in the same manner as in Example 1. The water absorption rate was 0.1%, and the hardness was 86 at 3horeD.

Example 4゜50 parts of compound (A) obtained in Production Example 2, hydrogenated dicyclopentadiene monoacrylate (manufactured by Hitachi Chemical Co., Ltd., FA)
-513A) (B) 50 copies, Irgacure-184 (
05 parts were mixed, and in the same manner as in Example 1, ultraviolet rays were irradiated from both sides for 8 seconds to obtain a disk substrate. The obtained substrate was used in Example 1.
It was evaluated in the same way. Water absorption rate is 0.2%, hardness is 5har
el) and 90 and ivy.

Example 5 35 parts of the compound (5) obtained in Production Example 1, 35 parts of the compound (1st generation) obtained in Production Example 2, dioxane glycol diacrylate (KAYARAD R-604, manufactured by Nippon Kayaku Corporation) (
B) 30 parts of Irgacure-184 (C1S part) were mixed and irradiated with ultraviolet rays for 10 seconds in the same manner as in Example 1 to obtain a disk substrate.The obtained substrate was evaluated in the same manner as in Example 1.

The water absorption rate was 0.3%, and the hardness was 92 at 5hole D.

Example 6 60 parts of the compound (5) obtained in Production Example 1, polyester polyacrylate [obtained by reaction of esterified product of hexahydrophthalic anhydride (1 mol) with totrimethylolpropane (2 mol) and acrylic acid] ) and 3 parts of Irgacure 184(C) were mixed and irradiated with ultraviolet rays in the same manner as in Example 1 to obtain a disk substrate. The obtained substrate was evaluated in the same manner as in Example 1. The water absorption rate was 0.1%, and the hardness was 5hole D and 85.

Example 7 100 parts of the compound (A) obtained in Production Example 2 and 1 part of Irgacure 1841C1S were mixed and cured with ultraviolet light in the same manner as in Example 1 to obtain a disk substrate. The obtained substrate was evaluated in the same manner as in Example 1. Water absorption rate is 0.2%, hardness is 5ho
It was 88 in re D.

Mix 50 parts of Nord A dimethacrylate and 5 parts of Irgacure-184 (C), and conduct f! It was cured with ultraviolet light in the same manner as IJ 1 to obtain a disk substrate. The obtained substrate was evaluated in the same manner as in Example 1. Water absorption rate is 0.15%,
The hardness was 82 (5 hare 1).

Comparative Example 1 So parts of 2.2-bis(4-methacryloyloxyethoxyphenyl)furopane, 50 parts of styrene, and 2 parts of lauroyl peroxycarbonate were mixed and poured into a glass mold in the same manner as in Example 1. It was cured in 15 hours while gradually increasing the temperature to ℃. The above formulation had a strong styrene odor when mixed or poured into a glass mold. The obtained disk substrate was evaluated in the same manner as in Example 1. Water absorption rate is 0.1%, hardness is 5hole
It was 90 in D.

Comparative Example 2 A methyl methacrylate resin was evaluated in the same manner as in Example 1. The water absorption rate was 0.5%, and the hardness was 5horeD and 91.

(Effects of the Invention) The ultraviolet curable resin composition of the present invention has a low water absorption rate and a short curing time of the cured product obtained by curing, and is particularly useful as a material for a disk substrate.

Claims (1)

[Claims] 1. a) One or more compounds (A) selected from the compounds represented by the following general formula [I] or [II] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ I] (In the formula, R_1 is H or CH_3.) ▲ Numerical formula,
There are chemical formulas, tables, etc. ▼ [II] (In the formula, R_2 is H or CH_3.) b) Compound (B) having one or more ethylenically unsaturated groups in the molecule as an optional component and c) An ultraviolet curable resin composition containing a photosensitizer (C). 2, a) One or more compounds (A) selected from the compounds represented by the following general formula [I] or [II] ▲There are numerical formulas, chemical formulas, tables, etc.▼ [I] (In the formula, R_1 is H or CH_3.) ▲ Formula,
There are chemical formulas, tables, etc. ▼ [II] (In the formula, R_2 is H or CH_3.) b) Compound (B) having one or more ethylenically unsaturated groups in the molecule as an optional component and c) An ultraviolet curable disk material characterized by containing a photosensitizer (C).