JPH0462554A - photosensitive composition - Google Patents

Abstract

PURPOSE:To provide the photosensitive composition hardenable in high sensitivity by cationic polymerization in spite of containing a colorant by incorporating a cationically polymerizable compound, a photopolymerization initiator, a condensed type azo pigment, and a sensitizer in the composition. CONSTITUTION:The photosensitive composition polymerizable by the cationic polymerization contains the cationically polymerizable compound, an aromatic iodonium salt, the condensed type azo pigment, and the sensitizer. Said azo pigment is the one having a molecular weight of >=1000 and synthesized through the 2 steps of coupling and condensation and superior in coloring power and resistances to solvents, light, and heat, and rapidly hardened in the presence of oxygen in spite of containing the colorant by using said pigment especially as a red and yellow pigment, and reduces deterioration of sensitivity. The aromatic iodonium salt is allowed to release a Lewis acid by irradiation with ultraviolet rays to start the cationic polymerization, and the photopolymerization initiator is used in combination with various kinds of sensitizers.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a photosensitive composition used for photosensitive inks, photosensitive paints, sealants, etc. In particular, it can be cured rapidly even in the presence of oxygen. This invention relates to a cationic polymerizable photosensitive composition.

[Conventional technology]

Yoto: Many photosensitive compositions are used that mainly consist of a compound having an acrylic group in its molecular structure and a photopolymerization initiator that generates radicals when irradiated with light.

However, in the radical polymerization reaction, oxygen becomes an inhibitor of polymerization, and there are problems in the photocuring reaction in the atmosphere (such as slow polymerization rate and residual stickiness on the surface of the resin coating of the photosensitive composition). As a result, exposure equipment has become expensive and large, and the cost has increased due to exposure in nitrogen, etc.In addition, epoxy resin, which has good electrical properties of the cured product and is widely used as the main component of sealants, Around this time, General Electric Co. reported a photosensitive composition using an aromatic onium compound as a polymerization initiator as a method for photocuring epoxy resins and vinyl ether resins, which had the problem of not being able to be cured by radical polymerization reactions. No. 50-151997, No. 52-14278
issue).

Photosensitive compositions produced by such cationic polymerization reactions have the advantage that they can be easily cured even in the atmosphere because they are not inhibited by oxygen. When cation radicals react, polymerization is stopped. For this reason, when a compound having a nitrogen atom in its molecular structure, especially a colorant added to UV ink, UV paint, sealant, etc., is added to the photosensitive composition, the sensitivity will be extremely reduced. [Problems to be solved by the invention] This was one of the major reasons for preventing the spread of polymeric photosensitive compositions. The object of the present invention is to provide a photosensitive composition that cures with high sensitivity regardless of the conditions.

[Means to solve the problem]

As a result of intensive studies to solve the above problems, the present inventors have arrived at the present invention.
A photosensitive composition that is cured by a cationic polymerization reaction, the composition containing at least a cationically polymerizable compound, an aromatic iodonium salt, a condensed azo pigment, and a sensitizer. It is.

In the present invention, by using condensed azo pigments as red and yellow pigments, the present invention cures quickly in the presence of oxygen and specifically reduces the decrease in sensitivity, despite the presence of a coloring agent. It is a photosensitive composition.

In the present invention, a condensed azo pigment (Dai) used as a colorant is a pigment with a molecular weight of 1000 or more that is synthesized through two steps of coupling and condensation, and has high coloring power and excellent solvent resistance, light resistance, and heat resistance. It is excellent in

As the cationically polymerizable compound used in the present invention, epoxy compounds having two or more oxirane rings in one molecule or vinyl ether compounds having two or more vinyl ether groups in one molecule are particularly desirable.

Examples of the epoxy compound include sphenol A type epoxy resin, novolak type epoxy resin, alicyclic type epoxy resin, and epoxidized polybutadiene.

Example 1: As a bisphenol A type epoxy resin,
Epicoat 828°834 manufactured by Yuka Shell Epoxy Co., Ltd.
836.1001. 1004. 1007, DER331, 332, 661, 664, 6 manufactured by Tau Chemical Company
67, Araldite 260.280 manufactured by Ciba Geigy
．． 6071.6084.6097 etc. are mentioned.

Ugly as novolak-type epoxy resins: Ebiko 152.154 manufactured by Yuka Shell Epoxy Co., Ltd., and Araldite EPN 1138 manufactured by Ciba Geigy Co., Ltd. ECN1235.
ECN1235, ECN1273. ECN1280
．． ECN1299, DEN431 manufactured by Dow Chemical Company
．． Examples include DEN438.

Ciba-Geigy's CY is used as a cycloaliphatic epoxy resin.
175. CY177, CY179. CY184.
Examples of CY192 and epoxidized polybutadiene include EPB12B and EPB27 manufactured by Nippon Soda Co., Ltd.

Examples of vinyl ether compounds include ethylene glycol divinyl ether, 2-chloroethyl vinyl ether,
-Hydroxyethyl vinyl ether, 4-chlorobutyl vinyl ether, 4-hydroxybutyl vinyl ether, and vinyl ether compounds synthesized from aromatic polyhydric alcohols.

1 charge as aromatic polyhydric alcohol Cresol, hydroquinone, 1,2.4-trihydroxybenzene, 1
Examples include 3.5-) dihydroxybenzene, 1.4-dihydroxy-2-7-er-7-butylbenzene, 1.4-dihydroxy-2,5-di-tert-butylbenzene, bisphenol A1, bisphenol S, and the like.

In the present invention, as a photopolymerization initiator, all commonly known compounds that generate radicals when exposed to light can be used. For example, aromatic iodonium salts, carbonyl compounds (benzoin methyl ether, etc.), anisyl, Benzyl compounds such as benzyl dimethyl ketal, quinone compounds such as anthraquinone and camphorquinone, thioxanthone compounds such as 2-chlorothioxanthone, etc.), azo compounds (azo compounds such as azobisisobutyronitrile, phenyl diazonium compounds such as diazonium salts, etc.), organic sulfur compounds (sulfide compounds such as tetramethylthiuram monosulfide, etc.), halogen compounds (silver halide compounds such as silver bromide, halogen compounds such as quinolinesulfonyl chloride) ), organometallic compounds (ferrocene etc.), metal carbonyl compounds (
Among them, aromatic iodonium salts are preferred.

Aromatic iodonium salt +3 used as a photopolymerization initiator in the present invention Releases a Lewis acid upon irradiation with ultraviolet rays to initiate cationic polymerization, and its production method is described in the literature (J, Am).

Chem, Soc, 75.2705 or 81
．． 342) etc.

The aromatic iodonium salt (R1 and R2 are each a phenyl group, a naphthyl penta-alkyl penta, or (a phenyl group, a phenyl group substituted with a halogen, a nitro group, an alkyl group, and an alkoxyl group). Minakami M is B, P, As,
An atom selected from Sb, Sn, Bi, and Fe, Q is a fluorine or chlorine atom, and n is a number larger by 1 than the valence of M. ). Specifically, 1-diphenyliodonium tetrafluoroborate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroarsenate, diphenyliodonium hexafluoroantimonate, di(p-tolyl)-iodonium hexafluoroarsenate, di(4- nitrophenyl)-iodonium bentafluorostanate, di(4-t-butylphenyl)-iodonium hexafluorostibiate, di-2-naphthyl-iodonium tetrafluoroborate, di(4-diphenylyl)-iodonium hexafluorophosphate, Di(3-methoxyphenyl)-iodonium hexafluoroarsenate, phenyl-naphthyl-iodonium tetrafluoroborate, phenyl-4-fluorophenyl-iodonium hexafluorophosphate, phenyl-(3,5-diisopropylphenyl)-iodonium penta Examples include fluorostanate.

The above photopolymerization initiator IL is used in combination with various sensitizers. For example, amines (aliphatic amines such as triethanolamine, aromatic amines such as ethyl-p-dimethylaminobenzoate, cyclic amines such as piperazine, etc.), ureas (such as diphenyl urea), sulfur compounds (
sodium diethyldithiophosphate, etc.), nitriles (dimethylaminobenzonitrile, etc.), phosphorus compounds (tri-n-butylphosphine, etc.), chlorine compounds (hexachloroethane, etc.), pigments (cyanine, black color),
Rose Bengal, etc.) can be used depending on the purpose.

A condensed azo pigment is a high-grade pigment whose molecular weight is increased by a condensation reaction after azo coupling. For example, PI
No, Red-242, Red-214, Red-
221° Orange-61 and the like.

In the present invention, a binder may be added to improve the dispersibility of pigments, photopolymerization initiators, and sensitizers. Preferred binders include polymethyl methacrylate, polyvinyl chloride, polyamide, polyethylene oxide, polycarbonate, It is a polymer compound such as polystyrene.

Furthermore, filling life L, reinforcing material, flame retardant L, antistatic mA, plasticizer, etc. may be mixed.

The amount of the condensed azo pigment contained in the photosensitive composition of the present invention is preferably in the range of 1 to 30% by weight. 1
If the amount is less than 30% by weight, the desired coloration cannot be obtained, and as the amount of pigment added increases, the sensitivity decreases. If it exceeds 30% by weight, the sensitivity and physical properties of the coating film are significantly reduced.

Further, the amount of aromatic iodonium salt and sensitizer added is preferably 01 to 30% by weight.

In general, increasing the amount added increases the sensitivity, but once added to a certain extent, the sensitivity becomes saturated.

〔Example〕

The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to these Examples.

Example 1 15 parts of condensed disazo pigment (PI No. Red-221, manufactured by Dainichiseika Chemical Industry Co., Ltd.) 10 parts of polymethyl methacrylate (Elvacite 2041, manufactured by DuPont) as a binder was dispersed in 300 parts of dichloromethane using a sand mill. A photosensitive resin liquid was prepared by dissolving 100 parts of a vinyl ether compound represented by the following structural formula (I), 5 parts of diphenyliodonium hexafluoroalcoholate, and 5 parts of diethylthioxanthone (manufactured by Nippon Kayaku) as a sensitizer in the dispersion liquid. 300 parts of 2-chloroethyl vinyl ether was dissolved in 500 parts of dimethylformamide and reacted at 50°C for 8 hours.Then, the reaction solution was washed twice with 100 parts of water to remove excess 2-chloroethyl vinyl ether. Obtained by removing the vinyl ether under vacuum at 60°C.

Next The resin solution was applied to a thickness of 101Jn on an aluminum plate using a percoater, and the curing speed was measured by irradiating it with ultraviolet rays.
W, manufactured by Ushio Inc.).The results are shown in Table 1.

Note that the sensitivity is expressed as the light irradiation time until the film surface loses its tackiness.

Comparative Examples 1 to 7 For comparison, the sensitivity of the pigments shown in Table 1 was measured in the same manner. The results are shown in Table 1.

As can be seen from Table 1, the sensitivity of the condensed disazo pigment is 172, which is 172 of the sensitivity of the system without the addition of colorant, but the sensitivity has significantly decreased to 175 to 1/20 for other colorants.

Synthetic heavy hydroquinone of structural formula (I) 100 parts Example 2 Epoxy-novolac resin (manufactured by Dow Chemical Company, DEN
431) 100 parts of dichloromethane, 20 parts of a condensed disazo pigment (PI No. Red-214 Sumiton Fast Red B, manufactured by Sumitomo Chemical Co., Ltd.) were dispersed in a sand mill, and 10 parts of diphenyliodonium hexafluoroalcoholate was dispersed therein. Sensitivity was determined in the same manner as in Example 1 by adding 10 parts of 2-chlorothioxanthone (manufactured by Tokyo Kasei Co., Ltd.). The results are shown in Table 2.

Comparative Example 8.9 Sensitivity was measured in the same manner as in Example 2 except that the pigment was changed to the pigment shown in Table 2. The results are shown in Table 2.

It can be seen that even in photosensitive compositions made of dipoxy resins, the reduction in sensitivity due to condensed disazo pigments is extremely small compared to other pigments.

〔Effect of the invention〕

As described above, the present invention can provide a photosensitive composition that reacts with high sensitivity even in the presence of oxygen, and can be cured using a simple exposure device. Furthermore, the present invention makes it possible to color cationic polymerized photosensitive compositions without significantly reducing their sensitivity.

Claims (1)

[Scope of Claims] 1. A photosensitive composition that is cured by a cationic polymerization reaction, which contains at least a cationically polymerizable compound, a photopolymerization initiator, a condensed azo pigment, and a sensitizer. A photosensitive composition characterized by: 2. The photosensitive composition according to claim 1, which contains 1 to 30% by weight of a condensed azo pigment. 3. The photosensitive composition according to claim 1, wherein the cationically polymerizable compound is an epoxy compound having two or more oxirane rings in its molecular structure. 4. The photosensitive composition according to claim 1, wherein the cationically polymerizable compound is a vinyl ether compound having two or more vinyl ether groups in its molecular structure.