JP3228432B2 - Optical disk material and its cured product - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disc recording medium for recording and reproducing an optical signal at high speed and high density. And an overcoat agent for optical discs having excellent hardness.

[0002]

2. Description of the Related Art At present, ultraviolet curable overcoat agents are used as overcoat agents for consumer compact disk recording media. On the other hand, at present, a writable and erasable optical disk is being developed, and an overcoat agent for an optical disk is also being developed.

[0003]

A recording medium for an optical disk is susceptible to moisture and heat shock, and has excellent qualities such as water resistance, heat shock resistance, high hardness and transparency as properties to an overcoat agent. Has been requested. Conventionally used overcoat agents for compact disks have insufficient properties and cannot be used as overcoat agents for optical disks.

[0004]

Means for Solving the Problems In order to solve the above problems, the present inventors have intensively studied and as a result, provided an overcoat agent for optical discs which cures rapidly by ultraviolet light, has excellent moisture resistance and excellent hardness. Was successful. That is, the present invention provides a compound (A) represented by the formula (1):

[0005]

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Wherein R 1 is a hydrogen atom or a methyl group, n
Is the number of 1 to 5. A) a compound having at least one ethylenically unsaturated group in a molecule other than (A) (B)
And a photopolymerization initiator (C) and a cured product thereof.

Specific examples of the compound (A) represented by the formula (1) used in the present invention include, for example, a reaction product of P-phenylphenol or O-phenylphenol with ethylene oxide or propylene oxide, ) It can be obtained by reacting acrylic acid. Reaction products of P-phenylphenol or O-phenylphenol with ethylene oxide or propylene oxide are readily available on the market. For example, manufactured by Sanyo Kasei Co., Ltd., Newpole OPE-20 (1 mole of O-phenylphenol reacted with 2 moles of ethylene oxide) Newpole OPE-40 (1 mole of O-phenylphenol with 4 moles of ethylene oxide) Are reacted.). P-
The reaction of a reaction product of phenylphenol or O-phenylphenol with ethylene oxide or propylene oxide and (meth) acrylic acid is carried out by a known method.
Preferably in the presence of an esterification catalyst such as toluenesulfonic acid or sulfuric acid and a polymerization inhibitor such as hydroquinone and phenothiazine, preferably in the presence of solvents (eg, toluene, benzene, cyclohexane, n-hexane, n-heptane, etc.). Can be obtained by reacting at a temperature of 70 to 150 ° C. (Meth) acrylic acid is used in an amount of usually 1 to 5 mol, preferably 1.05 to 2 mol, per 1 mol of a reaction product of P-phenylphenol or O-phenylphenol with ethylene oxide or propylene oxide. It is. The esterification catalyst is usually used in an amount of 0.1 to 15 mol% based on (meth) acrylic acid used,
Preferably it is present at a concentration of 1 to 6 mol%.

Specific examples of the compound (B) having one or more ethylenically unsaturated groups in a molecule other than the formula (1) used in the present invention include, for example, tricyclo [5,2,1,0
^2,6 ] decane (meth) acrylate (Hitachi Chemical Co., Ltd.)
Manufactured by FA-513A, FA-513M), isobornyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, tricyclodecane dimethylol di (meth) acrylate, neopentyl glycol di (meth) Acrylate, neopentyl glycol dihydroxypivalate di (meth) acrylate, dioxane glycol di (meth) acrylate (KAYARAD R-604, manufactured by Nippon Kayaku Co., Ltd.)
Monomers such as trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta and hexa (meth) acrylate, epoxy resins (for example, bisphenol A type epoxy resin) , Bisphenol F type epoxy resin, novolak type epoxy resin, etc.) and (meth) acrylic acid to obtain epoxy (meth) acrylate, polyester polyol (for example, polyvalent such as neopentyl glycol, ethylene glycol, trimethylolpropane, etc.) Reaction product of alcohol and polybasic acid such as succinic acid, phthalic acid, adipic acid, tetrahydrophthalic acid)
Polyester (meth) acrylates and polyols obtained by the reaction of
Polyethylene glycol, polypropylene glycol,
Polyetherne polyols such as polytetramethylene glycol, the polyester polyols, polycarbonate polyols and the like) and organic polyisocyanates (for example,
Isophorone diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, trimethylhexamethylene diisocyanate, etc.) and hydroxy (meth) acrylates (for example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 1,4-butane) Oligomers such as polyurethane (meth) acrylate obtained by reaction with diol (meth) acrylate).

Among these compounds (B), particularly preferred are tricyclodecane acrylate (FA-513A, manufactured by Hitachi Chemical Co., Ltd.), tetrahydrofurfuryl acrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, Neopentyl glycol diacrylate hydroxypivalate and bisphenol A type epoxy acrylate. One or more of these compounds (B) having one or more ethylenically unsaturated groups in the formula can be used.

Examples of the photopolymerization initiator (C) include benzoin ethyl ether, benzoin butyl ether,
2,2-diethoxyacetophenone, 4'-phenoxy 2,2-dichloroacetophenone, 2-hydroxy-2
-Methylpropiophenone, 4'-isopropyl-2-
Hydroxy-2-methylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, benzyl dimethyl ketone, benzophenone, 2-chlorothioxanthone,
2,4-diethylthioxanthone and the like. Particularly preferred are 1-hydroxycyclohexyl phenyl ketone, benzophenone and the like.

The amount of the component (A) used in the present invention is preferably 5 to 60% by weight of the overcoat agent for optical disks,
Particularly preferably, it is 10 to 40% by weight. The amount of the component (B) is preferably from 40 to 40 of the overcoat agent for optical disks.
It is 95% by weight, particularly preferably 60 to 90% by weight.
The amount of the component (C) is preferably from 0.1 to 10% by weight, particularly preferably from 1 to 7% by weight of the optical disc overcoat agent. The overcoat agent for optical disks of the present invention can be produced by mixing and dissolving the components (A) to (C).

The overcoat agent for optical discs of the present invention achieves its intended purpose sufficiently with only the components (A), (B) and (C). A polymerization inhibitor, a leveling agent, a silane coupling agent, an antioxidant, a light stabilizer and the like can be added as long as the characteristics of the above are not changed. The cured product of the optical disk overcoating agent of the present invention can be obtained by ultraviolet irradiation in a conventional manner. Specifically, for example, it can be obtained by irradiating ultraviolet rays using a low-pressure or high-pressure mercury lamp, a xenon lamp, or the like. The overcoat agent for optical disks of the present invention is particularly useful as an overcoat agent or a hard coat agent as a protective agent for a recording film of an optical disk.

The formation of the protective film for the optical disk recording film using the optical disk overcoating agent of the present invention is performed by applying the optical disk overcoating agent onto the optical disk recording film by, for example, a spin coating method or the like. Then, a protective film is formed by irradiating ultraviolet rays to cure. When an overcoat agent for an optical disc is applied on the recording film of the optical disc, the thickness is usually preferably about 1 to 30 μm.

[0014]

EXAMPLES The present invention will be described more specifically with reference to the following examples. Parts in Synthesis Examples and Examples are parts by weight. Synthesis example of compound (A) represented by formula (1) Synthesis example 1 258 parts of compound represented by formula (2)

[0015]

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(Reacted product of 1 mol of O-phenylphenol and 2 mol of ethylene oxide, product name, Newpol OPE-20, OH value 217.5, manufactured by Sanyo Chemical Co., Ltd.), 86.5 parts of acrylic acid, toluene 300 , 21 parts of sulfuric acid and 5 parts of hydroquinone were charged and heated, and the produced water was distilled together with the solvent, condensed, and cooled at the time when 18 parts of water was produced in the separator. The reaction temperature was 130-140 ° C. The reaction mixture was dissolved in 500 parts of toluene and 20%
After neutralization with an aqueous NaOH solution, the resultant is washed three times with 100 parts of a 20% aqueous NaCl solution. The solvent was distilled off under reduced pressure to obtain 303 parts of a compound. The viscosity was (25 ° C.) 204 centipoise.

Synthesis Example 2 346 parts of a compound represented by the formula (3)

[0018]

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(Sanyo Chemical Co., Ltd., reaction product of 1 mol of O-phenylphenol and 4 mol of ethylene oxide, product name, Newpol PPE-40, OH value 162) Acrylic acid 8
6.5 parts, 400 parts of toluene, 21 parts of sulfuric acid, and 6 parts of hydroquinone were charged and heated, and the produced water was distilled with a solvent, condensed, and the reaction mixture was cooled when 18 parts of water was produced in the separator. The reaction temperature was 130-140 ° C. The reaction mixture was dissolved in 500 parts of toluene and 20% NaOH
After neutralization with an aqueous solution, the resultant is washed three times with 100 parts of a 20% aqueous NaCl solution. The solvent was distilled off under reduced pressure to obtain 380 parts of a compound.
The viscosity was 120 cps (25 ° C.).

Embodiment 1 40 parts of the compound represented by the formula (1) obtained in Synthesis Example 1, 30 parts of trimethylolpropane triacrylate, 20 parts of neopentyl glycol diacrylate, 5 parts of tetrahydrofurfuryl acrylate and 1-hydroxycyclohexyl phenyl ketone (Ciba. 5 parts of Irgacure 184, a photopolymerization initiator (manufactured by Geigy Corporation) were mixed to obtain an overcoat agent for an optical disk of the present invention. The above optical disk overcoating agent was applied by a spin coater onto the optical disk recording film on which a recording film was prepared (by spargling) on a polycarbonate substrate, and was subjected to a high-pressure mercury lamp (Nihon Battery Co., Ltd., 2KW, 1 Light) and cured.
85% R at 80 ℃ with overcoated optical disk
When the sample was left in the state of H and subjected to a moisture resistance test, no abnormality was found in the recording film even after 1000 hours. No scratch was found when the cured surface was scratched with a nail.

Example 2 35 parts of the compound represented by the formula (1) obtained in Synthesis Example 2 and acryloyloxytricyclodecane (manufactured by Hitachi Chemical Co., Ltd.)
FA-513A) 40 parts, epoxy acrylate [resin obtained by esterifying Epicoat 828 (bisphenol A type epoxy resin manufactured by Yuka Shell Epoxy Co., Ltd.) with acrylic acid], 10 parts of neopentyl glycol diacrylate And 1845 parts of Irgacure were mixed to obtain an optical disk material of the present invention. Using this, an overcoated optical disk was obtained in the same manner as in Example 1. The test was conducted in the same manner as in Example 1. As a result of the moisture resistance test, no abnormality was observed even after 1000 hours. Further, no scratch was found even when the cured surface was scratched with a nail.

Example 3 40 parts of the compound represented by the formula (1) obtained in Synthesis Example 1, 25 parts of trimethylolpropane triacrylate, and neopentyl glycol diacrylate hydroxypivalate 2
5 parts, 5 parts of urethane acrylate (Goseirac-7000B, manufactured by Nippon Gosei Co., Ltd.), 5 parts of tetrahydrofurfuryl acrylate, 1845 parts of Irgaque, and 3 parts of γ-acryloyloxypropyltrimethoxysilane (silane coupling agent) were mixed. An optical disk material of the present invention was obtained. Using this, an overcoated optical disk was obtained in the same manner as in Example 1. The test was conducted in the same manner as in Example 1. As a result of the moisture resistance test, no abnormality was observed even after 1000 hours. Further, no scratch was found even when the cured surface was scratched with a nail.

Comparative Example 1 An optical disc was prepared in the same manner as in Example 3 except that the compound represented by the formula (1) obtained in Synthesis Example 1 was changed to trimethylolpropane triacrylate. Overcoat agent was obtained. Using this, an optical disk was obtained in the same manner as in Example 1, and the same test was performed. As a result of the moisture resistance test, a large number of pinholes were generated in the recording film after 200 hours had elapsed. No scratch was found when the cured surface was scratched with a nail. As described above, as is clear from the examples and comparative examples,
It is clear that the cured product of the overcoat agent for optical disks of the present invention has a high hardness and is excellent in moisture resistance.

[0024]

According to the overcoat agent for optical disks of the present invention, the cured product obtained by curing is high in hardness, and excellent in moisture resistance and adhesiveness.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08F 220/00-220/70

Claims (2)

(57) [Claims] A compound (A) represented by the formula (1): (Wherein, R1 is a hydrogen atom or a methyl group, and the average value of n is 1
There are numbers of ~ 5. A) an overcoat agent for optical discs, characterized by containing a compound (B) having at least one ethylenically unsaturated group in a molecule other than (A) and a photopolymerization initiator (C). 2. A cured product of the overcoat agent for optical disks according to claim 1.