JPH11306596A - Resin composition, resin composition for optical disk and its hardened material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin compsn. and its hardened material having high hardness and excellent moisture resistance which is suitable for an optical disk by incorporating 1,4-cyclohexane dimethanol monoacrylate, ethylene type unsatd. group-contg. compd. except for the first component, and a photopolymn. initiator as an optional component. SOLUTION: This resin compsn. for an optical disk is prepared by adding and mixing 50 pts.wt. of 1,4-cyclohexane dimethanol monoacrylate, 30 pts.wt. of trimethylol propane triacrylate, 20 pts.wt. of epoxyacrylate. and 5 pts.wt. of 1-hydroxycyclohexyl phenylketone including a photopolymn. initiator. After the resin compsn. is applied on a, recording film of an optical disk produced by forming the recording film on a polycarbonate substrat, is hardened by irradiation using a high pressure mercury lamp to form a protective film. Thus, the obtd. optical disk shows no abnormality in the recording film even when the disk is kept in a high temp. and high humidity state at 60 deg.C and 90% RH for 1000 hours and has high hardness as 85 Shore D hardness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition, particularly a resin composition useful as a resin composition for optical disks such as an overcoat agent for optical disks and an adhesive for optical disks, and a cured product thereof.

[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, writable and erasable optical disks have also become widespread, and overcoat agents and adhesives for optical disks have been developed.

[0003]

A recording medium for an optical disk is susceptible to moisture and heat shock, and has excellent characteristics to an overcoating agent, such as low warpage, water resistance, heat shock resistance, high hardness and transparency. Quality is required. Conventionally used overcoating agents for compact discs have insufficient properties and cannot be used as overcoating agents for recording films of optical discs.

[0004]

Means for Solving the Problems In order to solve the above problems, the present inventors have assiduously studied and, as a result, have developed a resin composition for optical disks which cures rapidly by ultraviolet light and has excellent adhesiveness, moisture resistance and hardness. It has succeeded in providing a suitable resin composition and a cured product thereof. That is, the present invention provides (1) 1,4-
Cyclohexane dimethanol monoacrylate (A) and an ethylenically unsaturated group-containing compound other than the component (A) (B)
And (2) a resin composition according to (1) for an optical disc, (3) (1) or (2), wherein the resin composition contains a photopolymerization initiator (C) as an optional component. And (4) an optical disc having a cured layer of the resin composition described in (3), and (5) an overcoat agent for an optical disc comprising the resin composition described in (1).

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, each component of the present invention will be described in detail. The component (A), 1,4-cyclohexanedimethanol monoacrylate, is acrylated by a known method such as an esterification reaction or a transesterification reaction of 1,4-cyclohexanedimethanol with acrylic acid or an acrylate ester. And commercially available from Mitsubishi Chemical Corporation.

As a specific example of the component (B), a compound having as little hydrophilicity as possible is preferred in order to improve the properties, and if it is broadly divided, it may be a low molecular weight monomer and a high molecular weight ethylenically unsaturated group-containing compound. Divided.

As the low molecular weight monomer, specifically, for example, tricyclo [5,2,1,0 (2,6 (superscript 1/4)
Corner))] decane (meth) acrylate, dicyclopentadieneoxyethyl (meth) acrylate, isobornyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, phenoxyethyl (meth) acrylate, neopentyl glycol di (meth) acrylate, Neopentylglycol hydroxypivalate di (meth) acrylate, tricyclodecane dimethylol di (meth) acrylate, bisphenol A polyethoxydi (meth) acrylate, bisphenol F polyethoxydi (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylol Propane polyethoxytri (meth) acrylate, trimethylolpropane polypropoxytri (meth) acrylate, pentaerythritol (Meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol poly (meth) acrylate of (meth)
Acrylate monomers can be mentioned.

The high molecular ethylenically unsaturated group-containing compound is obtained, for example, by a reaction between an epoxy resin and (meth) acrylic acid, an epoxy (meth) acrylate or a polyester polyol with (meth) acrylic acid. Polyurethane (meth) acrylates obtained by reacting polyester (meth) acrylates, polyols or polycarbonates with organic polyisocyanates and hydroxy (meth) acrylate compounds, and the like.

As an epoxy resin used in the synthesis of epoxy (meth) acrylate, for example, bisphenol A
Type epoxy resin, bisphenol F type epoxy resin or novolak type epoxy resin.

The polyester polyol used for the synthesis of the polyester (meth) acrylate is obtained by reacting a polyhydric alcohol with a polybasic acid. Examples of the polyhydric alcohol include neopentyl glycol, ethylene glycol, propylene glycol, 1,6-hexanediol, and trimethylolpropane. Examples of the polybasic acid include succinic acid, phthalic acid, hexahydrophthalic anhydride, Adipic acid, azelaic acid, tetrahydrophthalic anhydride and the like;

Polyols used for the synthesis of polyurethane (meth) acrylate include, for example, polyether polyols and polyester polyols. Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A polyethoxy diol, bisphenol A polypropoxy diol, and the like.

The polyester polyol is obtained by a reaction between a polyhydric alcohol and a polybasic acid. Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, 1,3-butylene glycol, neopentyl glycol, 1,4-benzenedimethylol, 2-ethyl-2-butyl-1,3-propanediol, polypropylene glycol, Polyethylene glycol and the like, and polybasic acids include, for example, succinic acid, adipic acid,
Isophthalic acid, terephthalic acid and the like.

The organic polyisocyanate used in the synthesis of the polyurethane (meth) acrylate includes, for example, isophorone diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, trimethylhexamethylene diisocyanate, diphenylmethane-4,4'-diisocyanate. Examples of the hydroxy (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate,
-Hydroxybutyl (meth) acrylate, pentaerythritol tri (meth) acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate and the like.

Among these compounds (B), particularly preferred are tetrahydrofurfuryl acrylate, tricyclodecane acrylate, neopentyl glycol diacrylate, tricyclodecane diacrylate, trimethylolpropane triacrylate, neopentyl glycol hydroxypivalate. Examples include diacrylate, tricyclodecane dimethylol diacrylate, acrylate of bisphenol A type epoxy resin, and polyurethane acrylate. These compounds (B)
One or two or more can be used.

The composition of the present invention can be cured by an energy beam such as an electron beam or an ultraviolet ray. In the case of curing by ultraviolet rays, it is necessary to use a photopolymerization initiator (C). As the photopolymerization initiator (C), any known photopolymerization initiator may be used. However, considering storage stability after blending, for example, benzoins, acetophenones, thioxanthones, ketals, benzophenone And 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

Benzoins include, for example, benzoin ethyl ether, benzoin butyl ether, benzoin isopropyl ether and the like, and acetophenones include, for example, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2. -Phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, N, N-
Dimethylaminoacetophenone and the like; thioxanthones include, for example, 2,4-diethylthioxanthone, 2-chlorothioxanthone and 2-isopropylthioxanthone; and ketals such as benzyldimethylketal and acetophenonedimethylketal. The benzophenones include, for example, benzophenone, methylbenzophenone, 4,4 ′
-Bisdiethylaminobenzophenone, 4-benzoyl-4'-methyldiphenylsulfide and the like. These photopolymerization initiators (C) can be used alone or in combination of two or more.

When the photopolymerization initiator (C) is used, ethyl N, N-dimethylaminobenzoate is further used.
N, N-dimethylaminobenzoic acid isoamyl ester,
Photosensitizers such as tertiary amines such as pentyl-4-dimethylaminobenzoate, triethylamine and triethanolamine can be used alone or in combination of two or more.

The amount of the component (A) used in the present invention is preferably 5 to 80% by weight, particularly preferably 10 to 60% by weight in the resin composition. The amount of the component (B) is preferably from 20 to 95% by weight, particularly preferably from 40 to 90% by weight.
% By weight. The amount of the component (C) is preferably from 0 to 15
%, Particularly preferably 1-10% by weight.

The resin composition of the present invention achieves its intended purpose sufficiently with only the components (A), (B) and (C) (optional components). A silane coupling agent, a polymerization inhibitor, a leveling agent, a colorant, a filler, and the like can be added as additives within a range that does not change the characteristics of the above. The amount of each of these additives is preferably in the range of 0 to 15% by weight of the composition.

The resin composition of the present invention comprises (A) and (B)
It can be prepared by adding components, and if necessary, component (C) and additives, and heating, mixing, and dissolving.

The resin composition of the present invention is preferably used as a resin composition for optical disks such as a protective agent for a recording film of an optical disk and an adhesive for DVDs. However, printing inks, coating agents, paints, adhesives, and castings are used. It can also be used for objects, eyeglass lenses, etc.

The cured product of the present invention can be obtained by irradiating the above-mentioned resin composition of the present invention with an energy ray such as an electron beam or an ultraviolet ray according to a conventional method. This cured product has high hardness and excellent moisture resistance.

The optical disk of the present invention has a cured layer of the resin composition of the present invention. The thickness of the cured product layer is usually 1
About 50 μm is preferable. This cured product layer is suitable as a protective film for a recording film of an optical disc. The protective film of the recording film of the optical disk is formed by applying the resin composition of the present invention (overcoating agent for an optical disk) on the recording film of the optical disk by, for example, a spin coating method and irradiating with ultraviolet rays to cure the composition. A protective film is formed. When the resin composition of the present invention is applied on a recording film of an optical disc, the thickness is usually preferably about 1 to 50 μm. In addition,
In these methods, the curing of the resin composition of the present invention comprises:
Electron beam irradiation can be used instead of ultraviolet irradiation.

[0024]

The present invention will be described below in more detail with reference to examples. Parts in Examples are parts by weight. Example 1 50 parts of 1,4-cyclohexanedimethanol mono-acrylate, trimethylolpropane triacrylate 3
0 parts, epoxy acrylate [Epicoat (registered trademark)
828 (a resin obtained by esterifying bisphenol A type epoxy resin manufactured by Yuka Shell Epoxy Co., Ltd.) with acrylic acid] 20 parts, 1-hydroxycyclohexyl phenyl ketone (Ciba Specialty Chemicals Co., Ltd.)
And Irgacure (registered trademark) 184, a photopolymerization initiator) were mixed to prepare a resin composition for an optical disk of the present invention. The above-mentioned resin composition for an ultraviolet-curable optical disk is applied by a spin coater onto the recording film of an optical disk in which a recording film is formed (by sputtering) on a polycarbonate substrate, and irradiated by a high-pressure mercury lamp (80 w / cm 2, one light). The composition was cured. The optical disk on which the protective film was formed was allowed to stand at 60 ° C. and 90% RH and subjected to a moisture resistance test. As a result, no abnormality was found in the recording film even after 1000 hours. The hardness of the composition was 85 Shore D. The hardness was measured by applying the composition to a thickness of 2 mm on a polycarbonate plate, curing with a high-pressure mercury lamp, and using a hardness meter (Shore D).

Example 2 45 parts of 1,4-cyclohexanedimethanol monoacrylate, trimethylolpropane triacrylate 20
Part, hydroxypivalate neopentyl glycol diacrylate (manufactured by Nippon Kayaku Co., Ltd., KAYARAD MA
NDA) (25 parts), epoxy acrylate (same as the epoxy acrylate used in Example 1) (10 parts) and Irgacure (1845) were mixed to prepare a resin composition for an ultraviolet-curable optical disk. Using this, an optical disc having a protective film formed thereon was obtained in the same manner as in Example 1. A test was conducted in the same manner as in Example 1, and the result of the moisture resistance test was 100
There was no abnormality even after 0 hours. Hardness is Shore D
Was 80.

Comparative Example 1 An optical disk was obtained and tested in the same manner as in Example 2, except that 1,4-cyclohexanedimethanol monoacrylate was changed to trimethylolpropane triacrylate. As a result of the moisture resistance test, 300
Many pinholes have been generated in the recording film since the lapse of time. The hardness was 92 on Shore D.

As is clear from the comparison between Examples and Comparative Examples, the cured product of the resin composition of the present invention has excellent moisture resistance.

[0028]

The resin composition of the present invention and the cured product thereof are:
It has high hardness and excellent moisture resistance, and is particularly useful for optical disks.

Claims (5)

[Claims] 1. A composition comprising a 1,4-cyclohexanedimethanol monoacrylate (A), an ethylenically unsaturated group-containing compound (B) other than the component (A), and a photopolymerization initiator (C) as an optional component. Characteristic resin composition. 2. The resin composition according to claim 1, which is used for an optical disk. 3. A cured product of the resin composition according to claim 1. 4. An optical disk having a cured product layer of the resin composition according to claim 3. 5. An overcoat agent for an optical disk comprising the resin composition according to claim 1.