JP2776522B2 - Photopolymerizable composition - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a photopolymerizable composition, and more particularly, to a photopolymerizable composition having improved photosensitive curing speed and storage stability.

[Prior Art and Problems to be Solved by the Invention] Photopolymerizable compositions are widely used in the production of printed circuit boards, integrated circuits, metal relief images and printing plates. The photopolymerizable composition usually contains a thermoplastic polymer binder, a photopolymerization initiator, a photosensitizer, an addition polymerizable compound, and the like, and is usually used in the form of a solution or a dry film. Is done. Then, a solution-type photopolymerizable composition or a dry film-form photopolymerizable composition dissolved in an organic solvent is applied or laminated on the surface of a copper-clad laminate for a printed board or a metal substrate to be subjected to fine processing. The resist image is formed by laminating, exposing a predetermined pattern with actinic rays, and developing an unexposed portion with a developing solution.

In addition, since the active region of the photopolymerization initiator is usually in the ultraviolet region, the exposure is performed with active light containing the ultraviolet region. Therefore, in order to increase the productivity of a printed wiring board or the like, it is required that the sensitivity to actinic rays is high and the photosensitive curing speed is high. In addition, in order to maintain stable photosensitive curability over a long period of time, the photopolymerization initiator and the photosensitizer contained in the photopolymerizable composition do not precipitate and are compatible with the thermoplastic polymer binder and the like. It is required to be excellent.

However, conventional photosensitizers and photopolymerizable compositions have a problem that the photosensitive curing speed is not yet sufficient, the exposure time becomes longer, and the productivity is reduced. In addition, the photosensitizer and the photo-heavy initiator are still insufficient in compatibility with the thermoplastic polymer binder and the like, and may lack storage stability of the photopolymerizable composition.

An object of the present invention is to provide a photopolymerizable composition which is excellent in compatibility with a thermoplastic polymer binder and the like and storage stability, and has a high photosensitive curing speed.

[Constitution of the Invention] As a result of intensive studies, the present inventors have found that when a specific alkylaminobenzoic acid alkyl ester, a thioxanthone and a specific thermoplastic polymer binder are combined, photosensitivity and compatibility are excellent. It has been found that a photopolymerizable composition having excellent photosensitive curing speed and storage stability can be obtained in combination with an addition polymerizable compound. That is, the present invention provides (a) at least a (meth) acrylic monomer and a carboxyl group-containing monomer, wherein the (meth) acrylic monomer has a weight ratio of an acrylate ester to a methacrylic ester. The former / the latter is a thermoplastic polymer binder composed of a copolymer of monomers with a ratio of 20/80 to 65/35
100 parts by weight, (b) 0.01 to 30 parts by weight of thioxanthone optionally having a halogen atom or an alkyl group, and (c) the following general formula (I) (Wherein, R ₁ represents a linear alkyl group having 6 to 10 carbon atoms,
R ₂ represents a methyl or ethyl group. R ₃ represents an alkyl group having 1 to 20 carbon atoms) alkylaminobenzoic acid alkyl ester represented by the formula:
(D) a liquid or solid addition polymerizable compound 10 at normal temperature and normal pressure;
The above problem is solved by a photopolymerizable composition containing up to 200 parts by weight.

First, the alkylaminobenzoic acid alkyl ester of the present invention will be described.

In the compound represented by the general formula (I), examples of the alkyl group of R ₁ and R ₃ include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, octyl, 2- Examples thereof include linear or branched alkyl groups such as ethylhexyl, nonyl, decyl, undecyl, dodecyl, tridecyl, octadecyl, and icosyl groups. However, the linear alkyl group of R ₁ has 6 to 10 carbon atoms, and the alkyl group of R ₃ has 1 to 20 carbon atoms. R ₂ is preferably a methyl or ethyl group, particularly a methyl group.

Among the compounds represented by the general formula (I), preferred alkylaminobenzoic acid alkyl esters include p- (N
-Hexyl-N-methylamino) methyl benzoate, p-
(N-hexyl-N-methylamino) ethyl benzoate,
propyl p- (N-hexyl-N-methylamino) benzoate, hexyl p- (N-hexyl-N-methylamino) benzoate, p- (N-hexyl-N-methylamino)
Amyl benzoate, p- (N-hexyl-N-methylamino) isoamyl benzoate, p- (N-heptyl-N-methylamino) methyl benzoate, p- (N-heptyl-N
Ethyl-methylamino) benzoate, propyl p- (N-heptyl-N-methylamino) benzoate, heptyl p- (N-heptyl-N-methylamino) benzoate, p-
(N-heptyl-N-methylamino) amyl benzoate,
Isoamyl p- (N-heptyl-N-methylamino) benzoate, methyl p- (N-octyl-N-methylamino) benzoate, p- (N-octyl-N-methylamino)
Ethyl benzoate, propyl p- (N-octyl-N-methylamino) benzoate, butyl p- (N-octyl-N-methylamino) benzoate, p- (N-octyl-N-
Methylamino) heptyl benzoate, amyl p- (N-octyl-N-methylamino) benzoate, isoamyl p- (N-octyl-N-methylamino) benzoate and the like.

The alkylaminobenzoic acid alkyl ester represented by the general formula (I) can be obtained, for example, by the following reaction formula. That is, a p-aminobenzoic acid ester is reacted with an aldehyde represented by the general formula R1aCHO in the presence of a reduction catalyst to obtain a monoalkylaminobenzoic acid ester, and then an alkyl halide represented by the general formula R ₂ X or It can be obtained by reacting with an alkylsulfonate or an aldehyde represented by R2aCHO.

(Wherein, R ₁ , R ₂ and R ₃ are the same as above. R _1a has 5 to 5 carbon atoms.
X is a halogen atom or OSO ₂ R ₄
Wherein R ₄ represents an aryl group or a linear alkyl group. R _2a represents a hydrogen atom or a methyl group. As the reduction catalyst used in the above reaction, for example, a palladium catalyst such as palladium carbon or pardium black is exemplified, and usually about 0.1 to 5% by weight is used.

The first-stage reaction is usually performed by hydrogenation in the presence of an organic solvent. As the organic solvent, for example, hexane, octane, aliphatic or alicyclic hydrocarbons such as cyclohexane, benzene, aromatic hydrocarbons such as toluene, chloroform, halogenated hydrocarbons such as carbon tetrachloride, methanol, ethanol , Propanol, alcohols such as isopropanol, acetone, ketones such as methyl ethyl ketone, methyl acetate, esters such as ethyl acetate, diethyl ether, tetrahydrofuran,
Examples thereof include ethers such as dioxane, aprotic polar solvents such as N, N-dimethylformamide, dimethylsulfoxide, and hexamethylphosphoric triamide, and a mixed solvent thereof.

The first-stage reaction is usually carried out under pressurized conditions at room temperature to 150 ° C.
The reaction is carried out with stirring at a temperature of approximately
It ends in about an hour.

When using an alkyl halide or an alkyl sulfonate represented by the general formula R ₂ X in the second-stage reaction,
The reaction can be carried out in the presence or absence of a basic catalyst. As the basic catalyst, alkali metal hydroxides, carbon salts and the like are suitable. As the reaction solvent, the above-mentioned solvents can be used, and the reaction can be carried out in the range of room temperature to the boiling point of the solvent.

When an aldehyde represented by the general formula R _2a CHO is used in the second-stage reaction, the reaction can be performed in the same manner as in the first-stage reaction.

In the above reaction, the first-stage reaction may be performed after the second-stage reaction is performed.

The alkylaminobenzoic acid alkyl ester as the target compound can be easily isolated and purified from the reaction mixture by a conventional separation and purification means such as a distillation method, a recrystallization method, a column chromatography, and a solvent extraction method. .

The compound represented by the general formula (I) has photosensitivity,
Since it has excellent compatibility with the specific thermoplastic polymer binder, it can be applied to various photopolymerizable compositions containing a photopolymerization initiator and an addition polymerizable compound.

Examples of the thermoplastic polymer binder include a copolymer of a (meth) acrylic monomer composed of an acrylate ester and a methacrylate ester and a carboxyl group-containing monomer, and a styrene monomer and an acrylate ester. A copolymer of a (meth) acrylic monomer composed of a methacrylic acid ester and a carboxyl group-containing monomer is used. When the above polymer is combined with the alkylaminobenzoic acid alkyl ester represented by the general formula (I), particularly excellent storage stability can be obtained.

Examples of the styrene monomer include styrene, α-substituted styrene in which the α-position is substituted with an alkyl group or a halogen atom, for example, α-methylstyrene, α-chlorostyrene, and the like; substituted styrene in which a hydrogen atom of a benzene ring is substituted For example, p-methylstyrene, p-ethylstyrene, p-propylstyrene, p-isopropylstyrene, p- (tert-butyl) styrene and the like are exemplified, and at least one kind is used. Among the styrene monomers, styrene, α-methylstyrene and the like are preferred.

As the acrylate, for example, methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, tert-butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate Octyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, and the like. Alternatively, examples of the methacrylate include a methacrylate corresponding to the above acrylate. One or more of these acrylates and methacrylates are used.

When the unexposed portion is removed and developed with an alkali developer or the cured film is peeled off, it is effective to copolymerize an addition polymerizable monomer having a carboxyl group.
Examples of such an addition-polymerizable monomer include maleic acid, itaconic acid, methacrylic acid, and acrylic acid.

The thermoplastic polymer can be composed of an appropriate ratio of each monomer, but when composed of a styrene monomer, an acrylate ester and a methacrylate ester, usually 10 to 60% by weight of a styrene monomer, an acrylate ester and Methacrylic acid ester is about 90 to 40% by weight. When an acrylate and a methacrylate are used in combination, the acrylate / methacrylate is usually used at a ratio of about 20 to 65/80 to 35% by weight, preferably about 30 to 50/70 to 50% by weight. Is done. The addition-polymerizable monomer having a carboxyl group is usually a styrene monomer,
Total amount of acrylate and methacrylate
About 15 to 40% by weight is used for 60 to 85% by weight.

The compound represented by the general formula (I) has excellent photosensitivity and is used in combination with thioxanthones which may have a halogen atom or an alkyl group. Examples of the thioxanthones include thioxanthone, its halogenated 2-chlorothioxanthone, its alkylated 2-methylthioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, and 2,4-
Examples thereof include dimethylthioxanthone, 2,4-diethylthioxanthone, and 2,4-dibutylthioxanthone.

Thioxanthones are other photoinitiators, such as 2
-Methylanthraquinone, 2-ethylanthraquinone,
Substituted or unsubstituted polyquinones such as 1,4-dimethylanthraquinone, 1-chloroanthraquinone and 2-chloroanthraquinone, benzophenone, 4,4'-bis (dimethylamino) benzophenone, 4,4'-bis (diethylamino ) Aromatic ketones such as benzophenone, benzoniones, benzoin ethers, benzyl, α, α-
It can be used in combination with various photopolymerization initiators such as oxime esters such as diethoxyacetophenone and benzophenone oxime acetate.

One or more photopolymerization initiators are used. The photopolymerization initiator is used in an amount of 0.01 to 30 parts by weight, preferably 1 to 15 parts by weight, based on 100 parts by weight of the thermoplastic polymer binder. If the photopolymerization initiator is used in an amount of less than 0.01 part by weight with respect to the thermoplastic polymer binder, the photocuring speed is not sufficient, and if it exceeds 30 parts by weight, the properties of the cured film deteriorate.

At least one kind of the alkylaminobenzoic acid alkyl ester represented by the general formula (I) is used. The alkylaminobenzoic acid alkyl ester is used in an amount of 0.01 to 30 parts by weight, preferably 1 to 15 parts by weight, based on 100 parts by weight of the thermoplastic polymer binder. If the amount of the alkylaminobenzoic acid alkyl ester is less than 0.01 part by weight, it is difficult to increase the photo-curing speed, and if it exceeds 30 parts by weight, the properties of the cured film deteriorate. The alkylaminobenzoic acid alkyl ester represented by the general formula (I) has excellent compatibility with a thermoplastic polymer binder and the like, contributes to stabilization of the photopolymerizable composition, and has a low photo-setting speed. Significantly promote.

In the anti-invention, in order to further improve the photocurability,
Using the thioxanthone or the like, an alkylaminobenzoic acid alkyl ester represented by the general formula (I), and 2,2,4,5-triarylimitazolyl dimonomers represented by the following general formula (II) in combination Is preferred.

(Wherein, Ar ₁ , Ar ₂ and Ar ₃ represent an optionally substituted aryl group) Examples of the 2,4,5-triarylimidazolyl dimer represented by the general formula (II) include: 2,2 ', 4,4', 5,5'-
Hexaphenylbisimidazole, 2,2'-di (o-
Chlorophenyl) -4,4 ', 5,5'-tetraphenylbisimidazole, 2,2'-di (o-chlorophenyl) -4,
4 ', 5,5'-tetra (m-methoxyphenyl) bisimidazole, 2,2'-di (o-fluorophenyl) -4,
4 ', 5,5'-tetraphenylbisimidazole, 2,2'-
Di (o-methoxyphenyl) -4,4 ', 5,5'-tetraphenylbisimidazole, 2,2'-di (p-chlorophenyl) -4,4', 5,5'-tetraphenylbisimidazole, 2,2'-di (p-chlorophenyl) -4,4 ', 5,5'-
Tetra (m-methoxyphenyl) bisimidazole, 2,
2'-di (p-fluorophenyl) -4,4 ', 5,5'-tetraphenylbisimidazole, 2,2'-di (p-methoxyphenyl) -4,4', 5,5'-tetra Examples thereof include phenylbisimidazole. Represented by the above general formula (II)
At least one 2,4,5-triarylimidazolyl dimer is used. The 2,4,5-triarylimidazolyl dimer represented by the general formula (II) is a thermoplastic polymer binder 10
It is used in an amount of 0.01 to 30 parts by weight, preferably 1 to 15 parts by weight based on 0 parts by weight. If the amount of 2,4,5-triarylimidazolyl dimer is less than 0.01 part by weight, it is difficult to increase the photo-curing speed, and if it exceeds 30 parts by weight, the properties of the cured film deteriorate.

Examples of the addition polymerizable compound include acrylates and methacrylates which are liquid or solid at normal temperature and normal pressure and have two or more acryloyl groups or methacryloyl groups in the molecule.

Examples of the acrylate having two acryloyl groups in the molecule include ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene gericol diacrylate, propylene glycol diacrylate, and dipropylene. Glycol diacrylate, tripropylene glycol diacrylate, tetrapropylene glycol diacrylate, polypropylene glycol diacrylate,
1,4-butanediol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, diacrylate of ethylene oxide adduct of bisphenol A, diacrylate of propylene oxide adduct of bisphenol A, hydrogenated bisphenol A A diacrylate of an ethylene oxide adduct of
Examples thereof include diacrylate of propylene oxide adduct of hydrogenated bisphenol A, N, N'-methylenebisacrylamide, and N, N'-benzylidenebisacrylamide.

Examples of the acrylate having three or more acryloyl groups in the molecule include glycerin triacrylate,
Examples thereof include trimethylolpropane triacrylate, trimethylolethane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate.

Examples of the methacrylate having two or more methacryloyl groups in the molecule include methacrylates corresponding to the above acrylates.

At least one of the above acrylates and methacrylates is used, and both may be used as a mixture. In addition,
Monofunctional acrylates and methacrylates may be appropriately used in combination.

The amount of the addition polymerizable compound is usually 10 to 200 parts by weight, preferably 20 to 15 parts by weight per 100 parts by weight of the thermoplastic polymer binder.
It is about 0 parts by weight.

The photopolymerizable composition of the present invention may contain, if necessary, a thermal polymerization reaction, a stabilizer for improving storage stability, a color former, a colorant for facilitating the discrimination of a resist image, and a plastic for imparting flexibility. And the like. Examples of the stabilizer include p-methoxyphenol, hydroquinone, hydroquinone monomethyl ether, tert-butylcatechol and the like, and are used in an appropriate amount as long as the photopolymerizability is not inhibited. As the color former, a leuco compound of a triarylmethane dye is useful. For example, leuco crystal violet, leucomalachite green, mineral salts such as hydrochloride and sulfate of these leuco bodies, p-toluenesulfonate And the like. Examples of the coloring agent include crystal violet, malachite green, Victoria blue, methylene blue and the like. Examples of the plasticizer include phthalic acid esters such as diethyl phthalate, dibutyl phthalate, diheptyl phthalate and dioctyl phthalate; aliphatic esters such as dioctyl adipate and dibutyl diglycol adipate; phosphates such as trimethyl phosphine;
Examples thereof include sulfonic acid amides such as toluenesulfonic acid amide.

The photopolymerizable composition of the present invention may be a liquid containing no organic solvent, but is usually used in the form of a dispersed liquid or a dry film which is insoluble in the organic solvent. Examples of the organic solvent include alcohols such as methanol, ethanol, and propanol; esters such as ethyl acetate; ketones such as ascent and methyl ethyl ketone; ethers such as diethyl ether and tetrahydrofuran; and halogenated hydrocarbons such as methylene chloride. And the like. The dry film is produced, for example, by applying a polymerizable composition to a base film such as a polyethylene terephthalate film and drying, and then laminating a cover film such as a polyethylene film with a pressure roll or the like. The thickness of the polymerizable composition of the dry film is not particularly limited as long as the resolution and workability are not reduced, but is usually 5 to 100 μm, preferably 20 to 70 μm.

The photosensitive layer comprising the photopolymerizable composition of the present invention is usually prepared by printing or coating a liquid photopolymerizable composition containing an organic solvent on a support such as a printed circuit board to remove the organic solvent or dry the photopolymerizable composition. It is formed by peeling the cover film of the film and laminating the film on the support with a rubber roll or the like.

The photosensitive layer is a light source that generates chemically active radiation,
For example, exposure is performed with a light source such as a low-pressure mercury lamp, an ultra-high-pressure mercury lamp, and a xenon lamp. Exposure is usually performed by providing a cover sheet on the photosensitive layer as necessary and using a negative or positive pattern mask by a contact method or a projection method. After exposure, development with a developer provides a resist image corresponding to the pattern. As the developing solution, a developing solution comprising an organic solvent such as perchloroethylene and trichloroethane, an alkaline developing solution containing a basic compound, and the like can be used. As the basic compound of the alkali developer,
For example, inorganic bases such as potassium carbonate, sodium carbonate, potassium bicarbonate, sodium bicarbonate, sodium silicate, and sodium phosphate; and organic bases such as trimethylamine, triethylamine, ethanolamine, diethanolamine, triethanolamine, morpholine, and pyridine are exemplified. Is done. Note that the alkali developer may contain an organic solvent such as ethylene glycol monobutyl ether.

When a circuit pattern is formed, after forming a resist image, the resist image is treated with a plating solution or an etching solution, and the resist image is peeled off with a strong alkaline aqueous solution such as sodium hydroxide or an organic solvent such as methylene chloride. .

The photopolymerizable composition of the present invention can be used as a photoresist when producing a printed wiring board, a circuit board, a metal relief image, a printing plate, or the like.

[Effects of the Invention] According to the photopolymerizable composition of the present invention, a specific alkylaminobenzoic acid alkyl ester is combined with a photopolymerization initiator, a thermoplastic polymer binder, and an addition polymerizable compound, so that the composition is excellent. It shows a photosensitive curing speed, shortens the exposure time as compared with a conventional photopolymerizable composition, and can increase the productivity of a printed wiring board and the like. Further, since the above alkylaminobenzoic acid alkyl ester is excellent in compatibility, the photopolymerizable composition of the present invention exhibits stable photocurable properties over a long period of time.

EXAMPLES Hereinafter, the present invention will be described in more detail based on examples.

Synthesis Example 1 p- (Nn-butyl-N
-Methylamino) ethyl benzoate was synthesized. That is, using a 500 ml reducing bottle, 10.0 g of ethyl p-aminobenzoate was dissolved in 100 ml of ethanol, and 6.55 g of n-butyraldehyde and 2.5 g of 5% palladium carbon were added.
The reaction was carried out at room temperature under a hydrogen pressure of 3 to 4 kg / cm ² for 2 hours until hydrogen absorption ceased. Then, 35% formalin aqueous solution 1
5.69 g, 1.5 g of 5% palladium carbon, and 3.10 g of sulfuric acid were added, and the reaction was further continued. After 1.5 hours of reaction, 3.9 kg / cm ² of hydrogen was absorbed, and the reaction was terminated. After filtering off the catalyst from the reaction solution, the solvent was distilled off to obtain 14.83 g of an oily product.

NMR spectrum (CDCl ₃ , δ) 0.7-1.7 (multiple line, 10H) 2.92 (single line, 3H) 3.30 (triple line, 2H) 4.25 (quadruple line, 2H) 6.51 (double line, 2H) 7.82 (Double line, 2H) IR spectrum (cm ⁻¹ , liquid film method) 2960, 2930, 1700 Boiling point 165 ° C./10 mmHg Synthesis Example 2 Instead of ethyl p-aminobenzoate and n-butyraldehyde in Synthesis Example 1, Amyl p-aminobenzoate and n
Amyl p- (Nn-octyl-N-methylamino) benzoate was obtained in the same manner as in Synthesis Example 1 except that -octylaldehyde was used.

 Example 1 The following components were mixed to obtain a photopolymerizable composition.

Copolymer of 20% by weight of methacrylic acid, 60% by weight of methyl methacrylate and 20% by weight of isobutyl acrylate 50g 2,4-Diethylthioxanthone 1g p- (Nn-octyl-N-methylamino) amyl benzoate 3g Methylolpropane triacrylate 15 g Tetraethylene glycol diacrylate 10 g Victoria blue GH 0.05 g Methyl ethyl ketone 60 g Tetrahydrofuran 10 g The obtained photopolymerizable composition was applied to a 25 μm-thick polyethylene terephthalate film support, dried at 75 ° C., and exposed to light. A functional film was obtained. The thickness of the photosensitive layer was 50 μm. The obtained photosensitive film was laminated on a polished copper-clad laminate using a rubber roller heated to 100 ° C. Next, a 21-step Stofa step tablet is superimposed on the drying film, irradiated with a 2 kw ultra-high pressure mercury lamp from a distance of 50 cm for 10 seconds to cure, and the polyethylene terephthalate film support is peeled off. , And a resin relief image corresponding to "8" on the step tablet was obtained.

Further, a 20 μm-thick polyethylene film was laminated on the photosensitive layer of the photosensitive film to prepare a dry film, which was stored for 6 months in a cool and dark place, and the photosensitive characteristics were evaluated in the same manner as above. The product exhibited the same photosensitive characteristics as described above.

Example 2 In place of the copolymer of Example 1, a copolymer of 14% by weight of methacrylic acid, 14% by weight of acrylic acid, 20% by weight of styrene, and 52% by weight of 2-ethylhexyl methacrylate was used.
A photopolymerizable composition was prepared. When the photosensitive characteristics were evaluated in the same manner as in Example 1, a resin relief image corresponding to "8" of the step tablet was obtained. The dry film after storage for 6 months also exhibited the same photosensitive characteristics as described above.

Example 3 To the photopolymerizable composition of Example 1, 1.5 g of 2,2'-di (p-chlorophenyl) -4,4 ', 5,5'-tetra (m-methoxyphenyl) bisimidazole was added. By mixing, a photopolymerizable composition was obtained.

When the photosensitive characteristics were examined in the same manner as in Example 1 except that the exposure time was set to about 7.5 seconds, a resin relief image corresponding to “8” of the step tablet was obtained, and the curing speed was high. Was. Further, the photopolymerizable composition,
Even after being stored in a dry film form for 6 months in a cool and dark place, the same photosensitive characteristics as above were exhibited.

Example 4 The photopolymerizable compositions of Examples 1 and 2 were added with 2,2'-
Di (o-chlorophenyl) 4,4 ', 5,5'-tetra (m-
2 g of (methoxyphenyl) bisimidazole was added and mixed to obtain photopolymerizable compositions.

When the photosensitive characteristics were examined in the same manner as in Example 1 except that the exposure time was set to about 7.5 seconds, a resin relief image corresponding to “8” of the step tablet was obtained, and the curing speed was high. there were. Each photopolymerizable composition was in the form of a dry film and exhibited the same photosensitive characteristics as described above even after being stored in a cool and dark place for 6 months.

Comparative Example 1 Among the components constituting the photocurable composition of Example 1, p-
A photopolymerizable composition containing no (Nn-octyl-N-methylamino) amyl benzoate was obtained. When this photopolymerizable composition was evaluated in the same manner as in Example 1, only a resin relief image corresponding to “4” of the step tablet was obtained.

Comparative Example 2 In the photopolymerizable compositions of Example 1 and Example 2, p- (N
A photopolymerizable composition was obtained using ethyl p- (N-butylamino) benzoate in place of -amyl-n-octyl-N-methylamino) benzoate.

When each photopolymerizable composition was evaluated in the same manner as in Example 1, only a resin relief image corresponding to “6” of the step tablet was obtained. The photosensitive properties of the photopolymerizable composition stored in a dry film for 6 months in a cool dark place were evaluated in the same manner as described above.
Only a resin relief image corresponding to 5) was obtained, and it was found that the photosensitive characteristics were reduced during storage.

Comparative Example 3 In the photopolymerizable composition of Example 4, p- (Nn-octyl-N-methylamino) amyl benzoate was replaced by p-
A photopolymerizable composition was obtained using ethyl (N-butylamino) benzoate.

When this photopolymerizable composition was evaluated in the same manner as in Example 1, only a resin relief image corresponding to “7” of the step tablet was obtained. Further, in the case of the photopolymerizable composition stored in a cool and dark place for 6 months in the form of a dry film, only a resin relief image corresponding to "6.5" of the step tablet was obtained, and it was found that the photosensitive characteristics were reduced during storage.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G03F 7/004-7/031 C08F 2/50

Claims (3)

(57) [Claims] 1. A composition comprising at least a (meth) acrylic monomer and a carboxyl group-containing monomer, wherein the (meth) acrylic monomer has a weight ratio of an acrylate ester to a methacrylate ester of the former / the latter = 20 / 80-65 /
35 parts by weight of a thermoplastic polymer binder composed of a copolymer of a monomer of 35, 0.01 to 30 parts by weight of thioxanthone optionally having a halogen atom or an alkyl group, ) (Wherein, R ₁ represents a linear alkyl group having 6 to 10 carbon atoms,
R ₂ represents a methyl or ethyl group. R ₃ represents an alkyl group having 1 to 20 carbon atoms) alkylaminobenzoic acid alkyl ester represented by the formula:
01 to 30 parts by weight, liquid or solid addition polymerizable compound at normal temperature and pressure 10 to 200
A photopolymerizable composition, comprising: 2. The light according to claim 1, wherein the thermoplastic polymer binder is a copolymer of a monomer composed of a (meth) acrylic monomer, a carboxyl group-containing monomer and a styrene monomer. Polymerizable composition. (3) 2,4,5-triarylimidazolyl dimer 0.01 to 30 per 100 parts by weight of the thermoplastic polymer binder.
The photopolymerizable composition according to claim 1, which contains parts by weight.