JPH09143391A - Overcoat composition for optical disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an overcoat compsn. which cures quickly and forms a cured coating film excellent in adhesion to a substrate, hardness, durability, etc., by incorporating a compd. having at least two terminal propenyl ether groups and a photochemical cationic polymn. initiator into the same. SOLUTION: This compsn. contains, as the essential components, 95-99.9wt.% at least one compd. (A) having at least two terminal propenyl ether groups in the molecule and selected from among a (poly)ether oligomer, a polyester oligomer, a urethane oligomer, and a monomer and 0.01-5wt.% photochemical cationic polymn. initiator (B). If necessary, the viscosity of the compsn. is adjusted with a reactive diluent, pref. a monopropenyl ether compd., in an amt. of 5-60wt.% of the sum of components A and B.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an overcoat composition for optical disks. More specifically, a photocationic curable overcoat containing a propenyl ether terminal group compound, which is cured at high speed by irradiation with light such as ultraviolet rays to form a cured coating film excellent in adhesion, hardness, durability with a recording medium. It relates to a composition.

[0002]

2. Description of the Related Art Conventionally, an overcoat agent has been applied to a recording film of an optical disc such as a compact disc recording medium. As the overcoat agent, a photoradical-curable overcoat agent such as unsaturated polyester, polyester (meth) acrylate, urethane (meth) acrylate, and epoxy (meth) acrylate (for example, JP-A-63-96036) is known. Has been. However, photo-radical polymerization type curing generally causes volume contraction, and the adhesiveness to the surface of the recording medium is likely to be lowered. Furthermore, the acrylic composition has a peculiar odor, and the work environment is not polluted or irritates the skin. There is a problem that it is expensive. further,
When air (oxygen) intervenes during UV curing, the radical curing reaction is hindered, so it is necessary to perform UV irradiation in an inert gas atmosphere, and there are restrictions in terms of the apparatus. To improve the problems of such radical curing type,
There is an epoxy-based photocationic curable resin, but since the resin has low photoreactivity, a large amount of UV energy is required at the time of curing. Therefore, there are drawbacks that a high UV energy irradiation device is required and that irradiation time is long. As a method for improving the low reactivity of such a photo-cationic curable resin, a method using an alicyclic epoxy compound as a base resin or a diluent has been proposed (JP-A-5-186755).

[0003]

However, the reaction rate of the photocationic curing type using the alicyclic epoxy compound is slower than that of the conventional radical photocurable resin, and the alicyclic type is industrially available. The types of epoxy compounds are limited, and it was difficult to obtain epoxy compounds that satisfy practical performance. The present invention is an organic solvent, an irritating monomer,
Provided is an overcoat composition for an optical disk which does not contain an oligomer or the like, is cured at a high speed by irradiating with an active energy ray such as UV, and has excellent adhesion to a disk substrate, durability, hardness and the like to give a cured product. The purpose is to The overcoat composition of the present invention has various problems in the prior art, namely, harmfulness to workers,
It significantly improves environmental pollution, odor problems, curing speed, coating film physical properties, etc.

The present inventors have arrived at the present invention as a result of extensive studies on an overcoating agent for an optical disk which solves the above problems. That is, the present invention is an overcoat composition for an optical disk, which comprises a compound (A) having at least two propenyl ether terminal groups in the molecule and a photocationic polymerization initiator (B) as essential components.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the compound (A) having at least two propenyl ether end groups in the molecule is, for example, a (poly) ether oligomer having a propenyl ether end group or a polyester oligomer having a propenyl ether end group. A urethane oligomer having a propenyl ether terminal group and a monomer having a propenyl ether terminal group, and particularly preferably a urethane oligomer having a propenyl ether terminal group.

The above-mentioned (poly) ether oligomer having a propenyl ether terminal group is a compound represented by the following general formula (1). ^{X 1 [-O- (AO) m} -R 1] n (1) { wherein, n is an integer of 2 to 200, the n-number of m 0 to
It is an integer of 200 and at least one of m is 1 or more. At least two of n R ¹ 's are propenyl groups, and the rest may be hydrogen atoms, alkyl, acyl or aryl groups. A is an alkylene, arylene, aralkylene or cycloalkylene group having 2 to 12 carbon atoms,
When m is 2 or more, A may be the same or different,
The (AO) m portion may be randomly added or block added. X ¹ is a polyhydric alcohol residue. ｝

In the general formula (1), A has 1 to 1 carbon atoms.
12 is a divalent group selected from the group consisting of alkylene, arylene, aralkylene and cycloalkylene groups, and examples of alkylene groups that can be used include methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, Examples include octylene, nonylene, decylene, undecylene and dodecylene. Examples of the arylene group include phenylene, naphthylene, anthrylene, phenanthrylene and the like. An example of aralkylene is:
Benzylene, 1-phenylene, 2-phenylene, 3
-Phenyl propylene, 2-phenyl propylene, 1-
Examples include phenyl propylene. Examples of cycloalkylene groups include cyclopentylene, cyclohexylene,
Examples thereof include cycloheptylene and cyclooctylene.
Of these, ethylene group and propylene group are preferable. When the alkylene group has more than 12 carbon atoms, the solubility of the photocationic polymerization initiator (B) described later becomes poor.

X ¹ is a polyhydric alcohol residue, and examples of the polyhydric alcohol include glycerin, polyglycerin (a dimer to 18-mer of glycerin, such as diglycerin, triglycerin, tetraglycerin) and ring-opening of glycidol. Polymers (compounds having a degree of polymerization of 2 to 5000), trimethylolalkanes (trimethylolethane, trimethylolpropane, trimethylolbutane, etc.) and their dimers, monopentaerythritol, dipentaerythritol, 1, Examples include 3,5-pentaerythritol, sorbitol, sorbitan sorbitan glycerin condensate, and the like. Of these, particularly preferable are glycerin, polyglycerin, and trimethylolalkane and its 2-3 trimers.

In the general formula (1), n m is usually an integer of 0 to 200, and at least one m is usually 1
The above is an integer of preferably 1 to 80, particularly preferably 1 to 5. When m exceeds 200, the viscosity becomes high (B)
Becomes difficult to dissolve.

Further, n is usually 2 to 200, preferably 3
Is an integer of -100, particularly preferably 3-5. n is 2
When it exceeds 00, the viscosity becomes high and it becomes difficult to dissolve the initiator (B). At least two of n R ¹ 's are propenyl groups, and the rest may be hydrogen atoms, alkyl, acyl or aryl groups.

Examples of the polyester oligomer having a propenyl ether terminal group in the present invention include compounds represented by the following general formula (2), (3) or (4).

[0012] {In the formula, m is an integer of 1 to 200, n is an integer of 2 to 200, and X ² and X ³ are HOX ² OH and HOX ³ OH, respectively.
Represented by alkylene diol, arylene diol,
It is a residue of any one of polyether diol, polyurethane diol or polycarbonate diol, Y ¹ is a polyvalent carboxylic acid residue, and Y ² is a divalent carboxylic acid residue. At least two of n R ¹ 's are propenyl groups, and the rest may be hydrogen atoms, alkyl, acyl or aryl groups. ｝

X ² in the general formula (2) is HOX ² O.
It is the residue of any one of alkylene diol, arylene diol, polyether diol, polyurethane diol or polycarbonate diol represented by H.

Specific examples of the alkylene diol represented by HOX ² OH include ethylene glycol, propylene glycol, 1,3-butane diol, 1,4-butane diol, 1,6-hexane diol and 1,9-nonane. Examples thereof include diol, neopentyl glycol and 1.4-cyclohexanediol. Of these, ethylene glycol and propylene glycol are preferable.

Specific examples of the arylene diol represented by HOX ² OH include catechol, bis (2-hydroxyphenyl) methane and bis (4-hydroxyphenyl).
Examples include methane and bisphenol A. Of these, bisphenol A is preferred.

Specific examples of the polyether diol represented by HOX ² OH include poly (oxyethylene) diol, poly (oxypropylene) diol, poly (oxytetramethylene) diol, ethylene oxide adduct of bisphenol A, and bisphenol. Examples thereof include propylene oxide adducts of A. Of these, poly (oxyethylene) diol and poly (oxypropylene) diol are preferable.

The degree of polymerization of the above polyether diol is usually 1 to 200, preferably 2 to 100, particularly preferably 3
-20.

Examples of the polyurethane diol represented by HOX ² OH include the reaction products of the following (i) and (ii). (I) A diol represented by H (OX ⁵ ) m-OH (where m is an integer of 1 to 200 and X ⁵ is a carbon number of 2 to 1).
2 is a divalent group selected from the group consisting of alkylene, arylene, aralkylene and cycloalkylene groups. ) (Ii) a diisocyanate represented by OCN-Z ³ -NCO (However, Z ³ is a divalent group selected from the group consisting alkylene, arylene, a group aralkylene and cycloalkylene.)

In the diol (i), m is an integer of usually 1 to 200, preferably 3 to 20.

In the above diol (i), X ⁵ is 2 selected from the group consisting of alkylene having 2 to 12 carbon atoms, arylene, aralkylene and cycloalkylene.
Examples of the alkylene group which is a valent group and can be used include methylene, ethylene, propylene, butylene, pentylene,
Hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene and the like can be mentioned. Examples of the arylene group include phenylene, naphthylene, anthrylene, phenanthrylene and the like. Examples of alkylene include benzylene, 1-phenylene, 2-phenylene, 3-phenylpropylene, 2-phenylpropylene, 1-phenylpropylene and the like. Examples of cycloalkylene groups include cyclopentylene, cyclohexylene, cycloheptylene, cyclooctylene and the like. Of these, an ethylene group and a propylene group are particularly preferable. Carbon number of alkylene group is 12
If it exceeds the range, the solubility of the polymerization initiator (B) becomes poor.

Examples of the diisocyanate (ii) above include toluene diisocyanate (TDI), p- and m-phenylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), 2,2. , 4-trimethylhexamethylene diisocyanate, 1,4-cyclohexane diisocyanate, 4,4′-dicyclohexylmethane diisocyanate (hydrogenated MDI), 4,4′-diphenylmethane diisocyanate (MDI), 3,3′-dimethyl-4,4 '-Diphenylmethane diisocyanate,
1,5-tetrahydronaphthalene diisocyanate, naphthalene-1,5′-diisocyanate, bis (2-methyl-3-isocyanatophenyl) methane, 4,4′-
Examples thereof include diphenylpropane diisocyanate, tetramethylxylene diisocyanate (TMXDI), isophorone diisocyanate (IPDI) and the like. Preferred among these are TDI, MDI, IPDI, T
MXDI, hydrogenated MDI and HDI.

Examples of the polycarbonate diol represented by HOX ² OH include compounds represented by the following general formula. (However, m is an integer of 1 to 200, and X ⁶ is a divalent group selected from the group consisting of alkylene, arylene, aralkylene, and cycloalkylene groups having 2 to 12 carbon atoms.)

M in the above general formula is usually 1 to 200,
It is preferably an integer of 3 to 20.

X ⁶ in the above general formula has 2 to 12 carbon atoms.
Is a divalent group selected from the group consisting of alkylene, arylene, aralkylene and cycloalkylene groups, and examples of alkylene groups that can be used include methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, Examples include octylene, nonylene, decylene, undecylene and dodecylene. Examples of the arylene group include phenylene, naphthylene, anthrylene, phenanthrylene and the like. Examples of alkylene include benzylene, 1-phenylene, 2-phenylene, 3-phenylpropylene, 2-phenylpropylene, 1-phenylpropylene and the like. Examples of cycloalkylene groups include cyclopentylene, cyclohexylene, cycloheptylene, cyclooctylene and the like. Of these, ethylene group and propylene group are preferable.

As X ³ in the general formula (2),
The same as those exemplified as X ^{2 in the} formula (2) can be mentioned, and X ² and X ³ may be the same or different.

In the general formula (2), Y ¹ is a divalent or higher polyvalent carboxylic acid residue, and Y ² is a divalent carboxylic acid residue. Examples of the dicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, oxalic acid, malonic acid, succinic acid,
Examples thereof include glutaric acid and adipic acid. Examples of the trivalent or higher polycarboxylic acid include trimellitic acid and pyrimellitic acid. Of these, Y ¹ and Y ² are preferably at least one selected from isophthalic acid, terephthalic acid and adipic acid.

In the general formula (2), m is usually 1 to 20.
It is an integer of 0, preferably 1-80, particularly preferably 1-20. When m exceeds 200, the viscosity becomes high and it becomes difficult to dissolve the polymerization initiator (B).

In the general formula (2), n is usually 2 to 20.
It is an integer of 0, preferably 3 to 100, particularly preferably 3 to 20. When n exceeds 200, the viscosity becomes high and it becomes difficult to dissolve the initiator (B). Further, at least two of n R ¹ are propenyl groups, and the rest are hydrogen atoms,
It may be an alkyl, acyl or aryl group.

Next, the polyester oligomer represented by the following general formula (3) will be described. {In the formula, m is an integer of 1 to 200, n is an integer of 2 to 200, X ² is an alkylene or arylene group,
X ¹ is a polyhydric alcohol residue. At least two of n R ¹ 's are propenyl groups, and the rest may be hydrogen atoms, alkyl, acyl or aryl groups. ｝

Examples of X ¹ in the general formula (3) are the same as those shown in the general formula (1),
Examples of X ² , m and n are the same as those shown in the general formula (2).

Next, the polyester oligomer represented by the following general formula (4) will be described. {In the formula, m is 1 to 200, n is an integer of 2 to 200, and X ² and X ³ are alkylene diols, arylene diols, polyether diols, and polyurethanes represented by HOX ² OH and HOX ³ OH, respectively. X ¹ is a polyhydric alcohol residue, which is the residue of either a diol or a polycarbonate diol. At least two of n R ¹ 's are propenyl groups, and the rest may be hydrogen atoms, alkyl, acyl or aryl groups. ｝

Examples of X ¹ in the general formula (4) are the same as those shown in the general formula (1),
Examples of X ² , X ³ , m and n are the same as those shown in the general formula (2). X ² and X ³ may be the same or different.

The urethane oligomer having a propenyl ether terminal group in (A) in the present invention is a compound represented by the following general formula (5). {In the formula, m is 0 to 200, n is an integer of 2 to 200, and Q ¹ is -OX ² O- or -N (R ² ) -X ⁴ -N (R
² )-, and Q ² is a group represented by -OX ² O-. X ² is an alkyl diol represented by HOX ² OH, an aryl diol, a polyether diol,
It is the residue of a diol, either a polyester diol or a polycarbonate diol. -N (R ²⁾ -X ⁴
—N (R ² ) — is a diamine residue represented by HN (R ² ) —X ⁴ —N (R ² ) H, and X ⁴ is alkylene having 2 to 12 carbon atoms, arylene, aralkylene or cyclo. It is an alkylene group, and R ² is an alkyl, aryl, aralkyl or cycloalkyl group having 2 to 12 carbon atoms. Z
¹ is a polyvalent isocyanate residue and Z ² is a divalent isocyanate residue. At least two of n R ¹ 's are propenyl groups, and the rest may be hydrogen atoms, alkyl, acyl or aryl groups. ｝

In the general formula (5), ² in Z ² is
As the valent isocyanate, the same ones as mentioned in the above formula (ii) can be mentioned. As the polyvalent isocyanate in Z ^1, in addition to the above divalent isocyanate, lysine ester triisocyanate, a modified diisocyanate (isocyanurate trimer, buret trimer,
Trimethylolpropane adduct, etc.), triphenylmethane triisocyanate, polyphenylmethane polyisocyanate, and the like.

In the general formula (5), Q ¹ is -OX ² O-.
Or ^{-N (R 2) -X 4 -N} (R 2) - in a group represented, Q ² is a group represented by -OX ² O-. X ² is H
OX ² OH is a diol residue represented by alkylene diol, arylene diol, polyether diol, polyester diol or polycarbonate diol, and X ² is the same as X ² in the general formula (2). There are things.

When the HOX ² OH is a polyester diol, the reaction products of the following (iii) and (iv) can be mentioned. (Iii) A diol represented by H (OX ⁷ ) m-OH (in the formula, m is an integer of 1 to 200 and X ⁷ is a carbon number of 2 to 12).
Is a divalent group selected from the group consisting of alkylene, arylene, aralkylene, and cycloalkylene groups. ) (Dicarboxylic acid (wherein represented by ^{iv) HOOC-Y 3 -COOH,} Y 3 is 2 selected alkylene, arylene, from the group consisting of groups aralkylene and cycloalkylene
Is a valence group. )

In the above-mentioned diol (iii), m is an integer of usually 1 to 200, preferably 3 to 20.

In the diol (iii) above, X ⁷
Is a divalent group selected from the group consisting of alkylene, arylene, aralkylene and cycloalkylene groups having 2 to 12 carbon atoms, and examples of the alkylene group that can be used include:
Methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene,
Examples thereof include decylene, undecylene and dodecylene.
Examples of the arylene group include phenylene, naphthylene, anthrylene, phenanthrylene and the like. Examples of alkylene include benzylene, 1-phenylene, 2-phenylene, 3-phenylpropylene, 2-phenylpropylene, 1-phenylpropylene and the like.
Examples of cycloalkylene groups include cyclopentylene, cyclohexylene, cycloheptylene, cyclooctylene and the like. Of these, ethylene group and propylene group are preferable. The alkylene group has 1 carbon atom
When it exceeds 2, the solubility of the polymerization initiator (B) becomes poor.

Examples of the dicarboxylic acid (iv) include phthalic acid, isophthalic acid, terephthalic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid and polycarboxylic acid. Of these, preferred are isophthalic acid, terephthalic acid and adipic acid. Examples of X ⁴ include the same as X ² in the general formula (2), R ² include the same as those represented by A in the general formula (1), and m and n are The same thing as what was shown by the said General formula (2) is mentioned.

The monomer having a propenyl ether terminal group in (A) of the present invention is a compound represented by the following general formula (6) or general formula (7). ^{X 1 [-O-R 1]} n (6) { wherein, n is an integer of 2 to 200, X ¹ is a polyhydric alcohol residue. At least two of n R ¹ 's are propenyl groups, and the rest may be hydrogen atoms, alkyl, acyl or aryl groups. ｝

In the general formula (6), n is usually 2 to 2.
00, preferably an integer of 2 to 6. When n exceeds 200, the viscosity is high and the handling becomes poor. Examples of X ¹ are the same as those shown in the general formula (1).

[0042] {In the formula, n is an integer of 2 to 200, X ² is a residue of any one of alkylene diol, arylene diol, polyether diol, polyurethane diol or polycarbonate diol represented by HOX ² OH, and Y ¹ Is a polyvalent carboxylic acid residue. At least two of n R ¹ 's are propenyl groups, and the rest may be hydrogen atoms, alkyl, acyl or aryl groups. } In the general formula (7), n is an integer of usually 2 to 200, preferably 2 to 6. When n exceeds 200, the viscosity is high and the handling becomes poor. Examples of Y ¹ and X ² are the same as those shown in the general formula (2).

As the photocationic polymerization initiator (B) used in the present invention, known photocationic polymerization initiators can be used. Specific examples of the (B) include triphenylsulfonium hexafluoroantimonate, triphenylsulfonium phosphate, p- (phenylthio)
Phenyldiphenylsulfonium hexafluoroantimonate, p- (phenylthio) phenyldiphenylsulfonium hexafluorophosphate, 4-chlorophenyldiphenylsulfonium hexafluorophosphate, 4-chlorophenyldiphenylsulfonium hexafluoroantimonate, bis [4-diphenyl-sulfonylio) phenyl ] Sulfide-bis-hexafluorophosphate, bis [4-diphenyl-sulfonyl) phenyl] sulfide-bis-hexafluoroantimonate, (2,4-cyclopentadien-1-yl) [(1-methylethyl) benzene] -Fe-hexafluorophosphate etc. can be mentioned. These are readily available from the market. Examples of commercially available products include "SP-150" and "SP-" manufactured by Asahi Denka Co., Ltd.
170 ";" Irgacure 26 manufactured by Ciba Geigy "
1 ";" UVR-697 "manufactured by Union Carbide Co.
4 ”,“ UVR-6990 ”and the like.

In the present invention, a reactive diluent (C) can be optionally used for the purpose of controlling the viscosity of the composition.

Examples of the (C) include compounds represented by the following general formula (8). CH ₃ —CH═CH—O—X ² —O—R ³ (8) (In the formula, X ² represents an alkylene diol, arylene diol, polyether diol, polyurethane diol, or polycarbonate diol represented by HOX ² OH. It is a residue of any diol, and R ³ has 2 to 2 carbon atoms.
12 alkyl, aryl, aralkyl or cycloalkyl groups, or a hydrogen atom. ｝

Examples of X ² in the above general formula (8) include the same as those shown in the above general formula (2), and R 2
³ is an alkyl, aryl, aralkyl or cycloalkyl group having 2 to 12 carbon atoms, or a hydrogen atom.

In the present invention, the weight ratio of (A) :( B) is usually (95-99.9) :( 0.01-).
5), preferably (96-98) :( 2-4).
If the ratio of (B) is less than 0.05, a sufficient polymerization initiation effect cannot be obtained, and even if it exceeds 5, the curing rate is not further improved and it is uneconomical.

When the reactive diluent (C) is used, the amount of the (C) is usually 5 to 60% by weight, preferably 10 to 30% by weight based on the total weight of (A) and (B). %. If the amount of the (C) exceeds 60% by weight, the curing rate will decrease.

If desired, the composition of the present invention may contain a known radical photopolymerizable composition (D).
The amount of (D) is 100 parts by weight of the composition of the present invention,
It is usually 0 to 100 parts by weight, preferably 0 to 40 parts by weight.

The composition of the present invention further comprises, if necessary,
Known epoxy resin (bisphenol A type epoxy resin, bisphenol F type epoxy resin, tetrabromobisphenol A type epoxy resin, novolac type epoxy resin, etc.), colorant, filler, non-reactive resin, leveling agent, antistatic agent, solvent , And other various additives may be contained.

The optical cation-curable overcoat agent for optical discs comprising the composition of the present invention is applied on the recording film of an optical disc and then cured at high speed by irradiating light energy such as UV to provide good adhesion and durability. Form a film with excellent properties. Further, during photocuring, unlike the conventional photoradical curable type, there is no inhibition of curing by oxygen in the air, and since there is almost no shrinkage during curing, the warpage during coating is extremely small.

The coating method on the optical disk recording film is not particularly limited, and known methods (spin coater, etc.) are used.
Can be used. Further, usable light includes UV emitted from a high pressure mercury lamp, a metal halide lamp, a low pressure mercury lamp and the like.

[0053]

The present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. The numerical values in the compounding composition column are parts by weight.

Examples 1 to 6 and Comparative Examples 1 to 3 were prepared using the overcoating agents prepared according to the formulation shown in Table 1.
It was applied by a spin coater on an optical disk having a recording film formed on a polycarbonate substrate by sputtering, and the photoreactivity and the moisture resistance of the cured film were evaluated according to the following evaluation methods and evaluation criteria. Table 1 shows the obtained evaluation results. Photoreactivity: UV on high pressure mercury lamp on the coated surface of overcoat
Was irradiated for a predetermined amount and the curability was observed. The curability was evaluated by rubbing the coated surface after irradiating a certain amount of UV with a cotton swab and the degree of adhesion of the uncured material to the cotton. Moisture resistance: An optical disc having a cured film obtained by irradiating UV of 900 mJ / cm ² was left in an atmosphere of 70 ° C. and 90% RH for 1000 hours, and the presence or absence of abnormality of the cured film was evaluated.

[0055]

[Table 1]

The compounds used in the formulations shown in Table 1 are as follows. The CH ₃ —CH═CH— group (propenyl group) is abbreviated as Pr. Propenyl ether end groups Compound (1): Pr-O- ( CH 2 CH 2 O) 12 -Pr propenyl ether end groups of compound (2): (Y: terephthalic acid residue) Propenyl ether end group compound (3): (X: triethylene glycol residue) (Z: 4,4′-diphenylmethane diisocyanate residue) propenyl ether end group compound (4): (X: triethylene glycol residues) propenyl ether end groups compound (5): R [O- ( CH 2 CH 2 O) 12 -Pr] 3 (R: glycerol residue) propenyl ether end groups of compound (6): (X ¹ : triethyleneglycerin residue) (Y: terephthalic acid residue) (X ² : residue of polyurethane diol of the following formula) (Z: 4,4'-diphenylmethane diisocyanate residue) Acrylate end group compound (7): Epoxy terminal group compound (8): "Epicoat 828"
(Bisphenol type epoxy resin manufactured by Yuka Shell Co., Ltd.) Alicyclic epoxy terminal compound (9): "ERL-422
1 "(manufactured by Union Carbide Corporation, alicyclic epoxy resins) reactive diluent (10): Pr-O- CH 2 CH 2 -OH reactive diluent (11): 2-hydroxyethyl acrylate reactive diluent ( 12): "BRL-4206" (manufactured by Union Carbide Co., alicyclic epoxy resin diluent) Photocationic polymerization catalyst (13): "UVR-6974"
{50% ethylene carbonate solution of a mixture of p- (phenylthio) phenyldiphenylsulfonium hexafluoroantimonate and bis [4- (diphenylsulfonyl) phenyl] sulfide bishexafluoroantimonate, manufactured by Union Carbide} Photoradical polymerization catalyst (14): "Irgacure 18
4 "(manufactured by Ciba Geigy)

[0057]

EFFECT OF THE INVENTION The photocationic curable overcoat composition for an optical disk containing the compound having a propenyl ether terminal group of the present invention has a better curability than that of a conventional radical polymerization acrylate-based optical disk, and can be used as a disk substrate. To form a cured coating film having excellent adhesion and moisture resistance. Also,
It is fast curable as compared with the one using a conventionally known epoxy UV cation curable resin. Because of the above effects, the photocationic curable composition of the present invention is extremely useful as an overcoating agent for protecting the recording film of an optical disk.

Claims (9)

[Claims] 1. An overcoat composition for an optical disk comprising a compound (A) having at least two propenyl ether terminal groups in the molecule and a photocationic polymerization initiator (B) as essential components. 2. (A) is selected from the group consisting of (poly) ether oligomers having propenyl ether end groups, polyester oligomers having propenyl ether end groups, urethane oligomers having propenyl ether end groups and monomers having propenyl ether end groups. The composition according to claim 1, which is one or more compounds selected. 3. The composition according to claim 2, wherein the (poly) ether oligomer having a propenyl ether terminal group is an oligomer represented by the following general formula (1). ^{X 1 [-O- (AO) m} -R 1] n (1) { wherein, n is an integer of 2 to 200, the n-number of m 0 to
It is an integer of 200 and at least one of m is 1 or more. At least two of n R ¹ 's are propenyl groups, and the rest may be hydrogen atoms, alkyl, acyl or aryl groups. A is an alkylene, arylene, aralkylene or cycloalkylene group having 2 to 12 carbon atoms,
When m is 2 or more, A may be the same or different,
The (AO) m portion may be randomly added or block added. X ¹ is a polyhydric alcohol residue. ｝ 4. The composition according to claim 2, wherein the polyester oligomer having a propenyl ether terminal group is an oligomer represented by the following general formula (2), general formula (3), or general formula (4). {In the formula, m is an integer of 1 to 200, n is an integer of 2 to 200, and X ² and X ³ are HOX ² OH and HOX ³ OH, respectively.
Represented by alkylene diol, arylene diol,
It is a residue of any one of polyether diol, polyurethane diol or polycarbonate diol, Y ¹ is a polyvalent carboxylic acid residue, and Y ² is a divalent carboxylic acid residue. At least two of n R ¹ 's are propenyl groups, and the rest may be hydrogen atoms, alkyl, acyl or aryl groups. ｝ {In the formula, m is an integer of 1 to 200, n is an integer of 2 to 200, X ² is an alkylene or arylene group,
X ¹ is a polyhydric alcohol residue. At least two of n R ¹ 's are propenyl groups, and the rest may be hydrogen atoms, alkyl, acyl or aryl groups. ｝ {In the formula, m is 1 to 200, n is an integer of 2 to 200, and X ² and X ³ are alkylene diols, arylene diols, polyether diols, and polyurethanes represented by HOX ² OH and HOX ³ OH, respectively. X ¹ is a polyhydric alcohol residue, which is the residue of either a diol or a polycarbonate diol. At least two of n R ¹ 's are propenyl groups, and the rest may be hydrogen atoms, alkyl, acyl or aryl groups. ｝ 5. The composition according to claim 2, wherein the urethane oligomer having a propenyl ether terminal group is an oligomer represented by the following general formula (5). {In the formula, m is 0 to 200, n is an integer of 2 to 200, and Q ¹ is -OX ² O- or -N (R ² ) -X ⁴ -N (R
² )-, and Q ² is a group represented by -OX ² O-. X ² is a residue of any one of alkyl diol, aryl diol, polyether diol, polyester diol or polycarbonate diol represented by HOX ² OH. -N (R ²⁾ -X ⁴ -
N (R ²⁾ - is ^{HN (R 2) -X 4 -N} (R 2) a diamine residue represented by H, X ⁴ is alkylene having 2 to 12 carbon atoms, arylene, aralkylene or cycloalkylene group And R ² is an alkyl, aryl, aralkyl or cycloalkyl group having 2 to 12 carbon atoms. Z ¹ is a polyvalent isocyanate residue and Z ² is a divalent isocyanate residue. At least two of n R ¹ 's are propenyl groups, and the rest may be hydrogen atoms, alkyl, acyl or aryl groups. ｝ 6. The composition according to claim 2, wherein the monomer having a propenyl ether terminal group is a compound represented by the following general formula (6) or general formula (7). ^{X 1 [-O-R 1]} n (6) { wherein, n is an integer of 2 to 200, X ¹ is a polyhydric alcohol residue. At least two of n R ¹ 's are propenyl groups, and the rest may be hydrogen atoms, alkyl, acyl or aryl groups. ｝ {In the formula, n is 2-200, X ² is a diol residue represented by HOX ² OH, which is any one of alkylene diol, arylene diol, polyether diol, polyurethane diol or polycarbonate diol, and Y
¹ is a polyvalent carboxylic acid residue. At least two of n R ¹ 's are propenyl groups, and the rest may be hydrogen atoms, alkyl, acyl or aryl groups. ｝ 7. A weight ratio of (A) :( B) is (95-9).
9.9): (0.01-5), The composition in any one of Claims 1-6. 8. A reactive diluent (C) is further compounded, and the content of (C) is 5 to 60% by weight based on the total weight of (A) and (B). 7. The composition according to any one of 7. 9. The composition according to claim 8, wherein (C) is a reactive diluent represented by the following general formula (8). CH ₃ —CH═CH—O—X ² —O—R ³ (8) (In the formula, X ² represents an alkylene diol, arylene diol, polyether diol, polyurethane diol, or polycarbonate diol represented by HOX ² OH. It is a residue of any diol, and R ³ has 2 to 2 carbon atoms.
12 alkyl, aryl, aralkyl, cycloalkyl group or hydrogen atom. ｝