JP3293924B2 - Radiation-curable resin composition, resin composition for optical material, and cured product thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultraviolet or electron beam which is useful as an optical material such as an overcoat agent, a hard coat agent and a groove material for an optical disk recording medium for recording and reproducing an optical signal at high speed and high density. The present invention relates to a radiation-curable resin composition, a resin composition for an optical material, and a cured product thereof that are cured and have good adhesion to a recording medium and good moisture resistance.

[0002]

2. Description of the Related Art Optical disks such as compact disks and magneto-optical recording disks have a structure having a metal thin film layer formed by vapor deposition or spargling on a transparent substrate such as polycarbonate. Since this metal thin film layer is affected by oxygen and moisture in the air and its characteristics are easily deteriorated, conventionally, a UV curable resin mainly composed of a thermoplastic resin or an acrylate ester has been used as an overcoat agent. However, adhesion and moisture resistance are insufficient, and corrosion is observed in the metal thin film layer in an environmental resistance test.

[0003]

The present invention provides a radiation-curable resin composition which is excellent in adhesiveness and moisture resistance and can form a cured film in which corrosion is not observed in a metal thin film layer of an optical disk in an environmental resistance test.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, have completed the present invention. That is, the present invention relates to formula (1)

[0005]

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(Wherein, R ₁ is a hydrogen atom, a methyl group or an ethyl group, R ₂ is a hydrogen atom or a methyl group, a and b are each a number from 0 to 10, and the average value of a + b is 1 to 20.) )
A radiation-curable resin composition comprising a compound (A) represented by the formula (I), a reactive monomer and / or a solvent (B) as a diluent, and a photopolymerization initiator (C) as an optional component. And a resin composition for an optical material and a cured product thereof. Compound (A) represented by Formula (1) used in the present invention
Is given by equation (2),

[0007]

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(Wherein R ₁ and a and b are the same as those of the formula (1)) and (meth) acrylic acid in a solvent (for example, toluene, benzene, cyclohexane, n
-Hexane, n-heptane, etc.). It is preferable to use an acid catalyst (for example, sulfuric acid, p-toluenesulfonic acid, methanesulfonic acid, etc.) to promote the reaction. During the reaction, a polymerization inhibitor (for example, hydroquinone,
It is preferable to use p-methoxyphenol, methylhydroquinone, etc.). The use ratio of the compound represented by the formula (2) and (meth) acrylic acid is such that 1 equivalent of the hydroxyl group of the compound represented by the formula (2) is
It is preferred to use ~ 2 equivalents. Reaction temperature is 70-1
The temperature is preferably 50 ° C., and the reaction time is preferably 3 to 20 hours.

The compound represented by the formula (2) can be obtained by reacting a fluorene compound having the following structural formula with ε-caprolactone.

[0010]

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[0011]

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[0012]

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The fluorene compound is reacted with 1 to 10 moles of ε-caprolactone per equivalent of hydroxyl group.
To promote the reaction, it is preferable to use stannous chloride, tetrapropyl titanate or the like as a catalyst. The amount of the catalyst used is 50 to 5000 ppm based on the reaction mixture.
Is preferred. The reaction temperature is preferably from 70 to 200 ° C, particularly preferably from 80 to 150 ° C. Reaction time is 1-2
0 hours is preferred.

The use ratio of the compound (A) represented by the formula (1) in the composition of the present invention is preferably in the range of 5 to 95% by weight, particularly preferably 10 to 50% by weight.

As specific examples of the reactive monomer and / or solvent (B) as a diluent used in the present invention, the reactive monomer includes, for example, carbitol (meth) acrylate,
Tetrahydrofurfuryl (meth) acrylate, dicyclopentenyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, acryloylmorpholine,
N-vinylpyrrolidone, N-vinylcaprolactone, tripropylene glycol di (meth) acrylate, tricyclodecane dimethylol di (meth) acrylate,
1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, nonanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra ( (Meth) acrylate, ditrimethylolpropanetetra (meth) acrylate, and the like. Examples of the solvent include methyllithyl ketone, carbitol acetate, butyl cellosolve acetate, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, and solvent naphtha. The proportion of the reactive monomer and / or solvent (B) used as a diluent in the composition of the present invention is preferably in the range of 5 to 95% by weight, particularly preferably 50 to 90% by weight.

As the photopolymerization initiator (C) used as an optional component in the present invention, various photopolymerization initiators used in general ultraviolet curable resins can be used. For example, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin butyl ether, 2-methylbenzoin, benzophenone, Michler's ketone, benzyldimethylketal, 2,2-diethoxyacetophenone, benzoylbenzoic acid, 4-benzoyl-4'-methyldiphenylsulfide , 3,3'-dimethyl-4-
Methoxybenzophenone, 1- (4-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexylphenyl ketone, 2
-Hydroxy-2-methyl-1-phenylpropane-1
-One, 2-methyl-1- [4- (methylthiophenyl)]-2-morpholinopropane-1, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2,4
-Diisopropylthioxanthone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide and the like can be mentioned as examples. Further, a photopolymerization accelerator such as an amine can be used in combination with these photopolymerization initiators.

The proportion of the photopolymerization initiator used in the composition of the present invention is preferably in the range of 0 to 15% by weight, particularly preferably 3 to 7% by weight. Examples of photopolymerization accelerators such as amines include 2-dimethylaminoethylbenzoate, dimethylaminoacetophenone, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, and the like. The use ratio of these photopolymerization accelerators is preferably 0 to 100 parts by weight based on 100 parts by weight of the photopolymerization initiator. The resin compositions (A), (B) and (C) of the present invention can be obtained by heating, mixing and dissolving the components. In the composition of the present invention, the above-mentioned components can sufficiently achieve the intended purpose.However, in order to further improve the performance, a silane coupling agent, a polymerization inhibitor, a leveling agent, etc. Additives can be added.

Examples of silane coupling agents that can be used include, for example, γ-methacryloxypropyltrimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane and the like. Can be

Examples of the polymerization inhibitor that can be used include, for example, hydroquinone monomethyl ether, t-butylcatechol, p-benzoquinone, 2,5-t-butyl-hydroquinone, phenothiazine and the like. Examples of the leveling agent include “Modaflow” manufactured by Monsanto Co., Ltd.

The use amount of these additives is preferably in the range of 0 to 5% by weight of the composition of the present invention. Radiation as used in the present invention is a general term for ionizing radiation, light, and the like, such as electron beams, α-rays, β-rays, γ-rays, X-rays, neutron rays or ultraviolet rays. The cured product of the radiation-curable resin composition of the present invention can be obtained by curing by irradiating the above-mentioned radiation according to a conventional method. The resin composition of the present invention is useful as an optical material such as an overcoat agent for an optical disk recording medium, a hard coat agent, and a groove material, but also includes a coating agent for metals, plastics, rubber, paper, wood and ceramics, and a paint. , Ink, resist lens, etc.

When the optical material resin composition of the present invention is used as an overcoat agent for an optical disk recording medium,
The composition of the present invention is applied to the metal thin film layer of the optical disc such that the dry coating thickness is 2 to 10 μm using a coating device such as a spicoter, and further, the metal film is irradiated with radiation such as ultraviolet rays. Overcoat (protection) on top
A layer is formed.

[0022]

The present invention will be described below in more detail with reference to Examples and Comparative Examples. In the following, all parts are by weight unless otherwise specified.

Synthesis Example of Compound (A) Synthesis Example 1 A compound represented by the formula (3) (manufactured by Nippon Steel Chemical Co., Ltd.)
438 parts, ε-caprolactone 1 (trade name “BPHE”)
14 parts and stannous chloride 0.17 parts were charged, heated to 130 ° C., and reacted for about 10 hours. Unreacted ε-caprolactone was reduced to 1% by weight or less. Parts, 173 parts of acrylic acid, 70 parts of p-toluenesulfonic acid, and 10 parts of hydroquinone.
The mixture is heated to perform a dehydration reaction, and the reaction is continued until the amount of distillate reaches 36 parts. The reaction temperature was 105-125 ° C. Then, the reaction solution was cooled, 2,000 parts of toluene and 250 parts of a 20% aqueous sodium hydroxide solution were charged and neutralized, and then washed with 500 parts of a 20% aqueous sodium chloride solution to remove toluene to obtain a transparent pale yellow solid. . The refractive index (25 ° C.) was 1.59.

Synthesis Example 2 438 parts of the compound represented by the above formula (3), 342 parts of ε-caprolactone, and 0.23 part of stannous chloride were charged.
The mixture was heated to 30 ° C. and reacted for about 10 hours. Since unreacted ε-caprolactone became 1% by weight or less, it was cooled to 60 ° C., and then 800 parts of toluene, 173 parts of acrylic acid, p
-80 parts of toluenesulfonic acid and 10 parts of hydroquinone are charged, heated and subjected to a dehydration reaction, and the reaction is continued until the amount of distillate reaches 36 parts. The reaction temperature was 110-125 ° C. Next, the reaction solution was cooled, and 2500 parts of toluene and 250 parts of a 20% aqueous sodium hydroxide solution were charged and neutralized, and then washed with 700 parts of a 20% aqueous sodium chloride solution to remove toluene, and a pale yellow transparent liquid was obtained. Obtained. The refractive index (25 ° C.) was 1.54.

Example 1 30 parts of the compound obtained in Synthesis Example 1, 30 parts of trimethylolpropane triacrylate, 25 parts of 1,6-hexanediol diacrylate, 10 parts of tetrahydrofurfuryl acrylate and Irgacure 184 (Ciba Geigy) 1-hydroxycyclohexyl phenyl ketone)
Five parts were mixed and dissolved to obtain a resin composition of the present invention. Next, the resin composition obtained above was applied on a recording film of an optical disk in which aluminum was vapor-deposited on a polycarbonate substrate using a spin coater so as to have a thickness of 5 μm, and irradiated with a metal halide lamp (120 w / cm). ,
The coating was cured. The obtained overcoated optical disk was placed in a constant temperature and humidity chamber at 75 ° C. and 85 RH% for 2000 hours.
After standing for a while, the recording film was observed, and no abnormalities were observed.

Example 2 40 parts of the compound obtained in Synthesis Example 2, 20 parts of hopopentyl glycol diacrylate, 35 parts of dicyclopentenyl acrylate, and 184 and 5 parts of Irgacure were mixed and dissolved to obtain a resin composition of the present invention. Was. Next, an overcoated optical disk was obtained in the same manner as in Example 1. After leaving in a thermo-hygrostat for 2000 hours in the same manner as in Example 1,
As a result of observing the recording film surface, no abnormality was recognized.

Comparative Example 1 A resin composition was prepared in the same manner as in Example 1 except that 30 parts of trimethylolpropane triacrylate was used in place of 30 parts of the compound obtained in Synthesis Example 1. Thus, an overcoated optical disk was obtained. Example 1
In the same manner as in the above, the recording film surface was observed after standing in a thermo-hygrostat for 50 hours. As a result, the entire recording film was corroded.

[0028]

The resin composition of the present invention has good adhesion of a cured coating film to a recording medium and good moisture resistance, and effectively prevents corrosion of a metal layer and a thin film layer of an optical disk for a long period of time. be able to. Therefore, the resin composition of the present invention is extremely useful especially as an optical material such as an overcoat agent for an optical disk.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI G03F 7/027 G11B 7/24 534 G11B 7/24 534 B41M 5/26 Y (56) References JP-A-4-325508 (JP, A) JP-A-5-215902 (JP, A) JP-A-5-170702 (JP, A) JP-A-7-2939 (JP, A) JP-A-4-337307 (JP, A) JP-A-6-220148 (JP, A) JP-A-6-220131 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08F 20/00-20/70 C08F 299/00-299/08 CA ( STN) REGISTRY (STN)

Claims (3)

(57) [Claims] (1) Formula (1) (Wherein, R ₁ is a hydrogen atom, a methyl group or an ethyl group, R ₂
Is a hydrogen atom or a methyl group, a and b are each a number of 0 to 10, and the average value of a + b is 1 to 20. (A), a radiation curable resin composition comprising a reactive monomer and / or a solvent (B) as a diluent and a photopolymerization initiator (C) as an optional component. . 2. A compound (A) represented by the formula (1) according to claim 1, a reactive monomer and / or a solvent (B) as a diluent and a photopolymerization initiator (C) as an optional component. A resin composition for an optical material, comprising: 3. A cured product of the resin composition according to claim 1 or 2.