JPH0610203B2 - Photopolymerization curing composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photopolymerizable composition which is cured by irradiation with light and can be developed with an alkaline aqueous solution. More specifically, it relates to a photopolymerizable curable composition having improved resistance to etching, plating and the like after development.

[Conventional technology and problems]

In general, a photopolymerization cured product is a substrate, for example, a copper clad laminate, is coated on a metal surface to be subjected to microfabrication, is laminated by lamination, etc., and is exposed to actinic light to cure the exposed portion,
The unexposed area is dissolved and removed by a solvent having an appropriate solubility. The solvent is roughly classified into one using an organic solvent such as 1,1,1-trichloroethane and one using an aqueous solvent such as an aqueous solution of sodium carbonate.

In recent years, a photopolymerizable composition that develops with an aqueous solvent has been gradually used in terms of work environment, surrounding environment, and manufacturing cost.

However, as compared with the case of using a conventional organic solvent developing type photopolymerization / curing composition, there are many restrictions on the treatment of etching and plating, and this often causes a problem in use.

[Means for solving problems]

As a result of intensive studies to solve such problems, the present inventors have found that an addition-polymerizable compound-type thermoplastic polymer binder obtained by copolymerizing an addition-polymerized monomer having a specific structure is more resistant. The present invention has been found to be improved.

That is, the present invention includes (1) 4 to 40% by weight of a carboxyl group-containing addition-polymerizable monomer (A) and at least 5% by weight of the following non-acidic addition-polymerizable monomer (B) and the following non-acidic monomer: Thermoplastic polymer binder 100 copolymerized with addition-polymerized monomer (C)
Based on parts by weight, non-acidic addition-polymerized monomer (B): at least one of acrylic acid ester or methacrylic acid ester monomer represented by the following general formula (I) (R ₁ is a hydrogen atom or a methyl group, R ₂ is an alkylene group having 1 to 5 carbon atoms, R ₃ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom, and n is an integer of 1 to 20. ) Non-acidic addition-polymerizable monomer (C): at least one non-acidic addition-polymerizable monomer having a Q value and an e-value satisfying the following formula (II) (Q _A and e _A are Q value and e value of addition polymerization monomer (A), and Q _C and e _C are Q value and e value of addition polymerization monomer (C)) (2) 50 at normal pressure Addition-polymerizable compounds having a boiling point of ℃ or higher 10
To 200 parts by weight and (3) a photoinitiator and / or 0.01 to 30 parts by weight of a photoinitiator system, the present invention relates to a photopolymerizable curable composition.

First, the thermoplastic polymer binder used in the present invention will be described in detail. In the photopolymerizable cured composition of the addition polymerizable compound type according to the present invention, the resistance of the resist film is largely dependent on the properties of the polymer binder. The acidic addition-polymerization monomer (A) having a carboxyl group in the copolymer forming the polymer binder of the present invention imparts developability to the copolymer, and accounts for the proportion in the copolymer composition. As 4
It is in the range of 40 weight percent. The appropriate ratio varies depending on the type of the developing solution. For example, the so-called semi-aqueous solution developing type containing ethylene glycol monobutyl ether or the like contains 4 to 15% by weight, and the complete aqueous solution developing type contains 15 to 15% by weight.
The range of 40 weight percent can be used as a rough guide. Of course, the optimum copolymerization rate of the acid addition polymerization monomer of the semi-aqueous solution type or the complete aqueous solution type varies depending on the developing solution and the developing conditions. In the present invention, the addition polymerization monomer having a carboxyl group (A), methacrylic acid,
A mixture of methacrylic acid and acrylic acid is preferred.

Since the acidic addition-polymerized monomer is copolymerized, the thermoplastic polymer binder essentially swells and dissolves in an alkaline liquid. Therefore, it is essential to copolymerize a non-acidic addition monomer in order to impart resistance. Particularly, a non-acidic addition-polymerizable monomer (B) which is an acrylic acid ester or a methacrylic acid ester having a specific structure is effective for improving the resistance to an alkaline aqueous solution.

Examples of such compounds include 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, 2-phenoxypropyl acrylate, 3-phenoxypropyl acrylate, phenoxydiethoxy acrylate, phenoxytriethoxy acrylate, and phenoxyacrylate. Dipropoxy, P-chlorphenoxyethyl acrylate, P-methylphenoxyethyl acrylate, 2-phenoxypropyl methacrylate, 3-phenoxypropyl methacrylate, phenoxydiethoxy methacrylate, phenoxytriethoxy methacrylate, phenoxydipropoxy methacrylate , P-chlorophenoxyethyl methacrylate, P-methylphenoxyethyl methacrylate, and the like, but are not limited thereto. At least 5 of these non-acidic addition-polymerizable monomers (B) are contained in the copolymer.
It must be contained in a weight percentage or more.

The non-acidic addition-polymerized monomer (C) serves as a component that imparts resistance together with the addition-polymerized monomer (B), and additionally has a role of controlling the glass transition point (Tg) of the copolymer. A suitable copolymer Tg is between 40 ° C. and 120 ° C., and at 40 ° C. or lower, when the photosensitive layer is sandwiched between the support film and the protective film, the photosensitive layer flows out with time when used as a “dry film”. "Cold flow" phenomenon occurs and 120 ℃
In the above case, the adhesion of the photosensitive layer to the substrate is significantly impaired.

Furthermore, the non-acidic addition-polymerizable monomer (C) has a function of forming a copolymer in which the acidic addition-polymerization monomer (A) is as uniformly and intramolecularly weighted as possible. If the acidic addition-polymerized monomers are not uniformly polymerized, not only will the development of the cured composition be poor, but in the worst case, precipitation of the copolymer during polymerization and precipitation of the copolymer during blending with the coating liquid will occur. Occurs. Such non-acidic addition-polymerized monomer (C) is determined according to the acidic addition-polymerized monomer (A). For example, polymerized monomer (A)
When methacrylic acid (Q _A = 2.340, e _A = 0.650) is selected as, methyl methacrylate (Q _C = 0.740, e _C = 0.400, Ethyl methacrylate (Q _C = 0.730, e _C = 0.520, And so on. In this case, n-butyl acrylate (Q _C = 0.500, e _C = 1.060, Then, methacrylic acid is rapidly consumed during the polymerization, resulting in a non-uniform copolymer composition, and in some cases precipitation occurs.

Incidentally, in the case of using a plurality of acidic addition polymerization monomers (A) in the present invention, the non-acidic addition polymerization monomer (C) is at least one acidic addition polymerization monomer (A) among them. It satisfies the above formula (II).

Next, it is added to the photopolymerizable cured composition of the present invention at 50 ° C.
Examples of the addition-polymerizable compound having the above boiling point include styrene-based compounds such as styrene, α-methylstyrene, and chlorostyrene, methyl (meth) acrylate (means methyl acrylate and methyl methacrylate, and the same applies hereinafter), Ethyl (meth) acrylate, n- and i-propyl (meth) acrylate, n
-, Sec- and t-butyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, butoxyethyl (meth) acrylate, cyclohexyl ( Meta)
Monofunctional (meth) acrylate compounds such as acrylate, phenoxyethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, (meth) acrylonitrile , (Meth) acrylamide, (meth) acrylamides such as N-methylol (meth) acrylamide, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, propylene glycol di (Meth) acrylate, dipropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth Bifunctional (meth) acrylates such as acrylate, 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate ) Trifunctional or higher functional (meth) acrylates such as acrylate, trimethylolethane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, di (meth) acrylate of ethylene oxide and / or propylene oxide adduct of bisphenol A, hydrogen (Meth) acrylates such as di (meth) acrylate of ethylene and / or propylene oxide adduct of modified bisphenol A, N, N'-methylenebis (meth) acrylamide, N, N'-benzylidenebis (meth) acrylic acid De like bisacrylamide such as, but not limited thereto. In the composition of the present invention, these addition polymerizable compounds are contained in an amount of 10 to 200 parts by weight based on 100 parts by weight of the thermoplastic polymer binder.

The photoinitiators and / or photoinitiator systems that can be used in the compositions of the present invention include:

That is, there are substituted or unsubstituted polynuclear quinones, for example, 2
-Ethyl anthraquinone, 2-tert-butyl anthraquinone, octamethyl anthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone,
1-chloroanthraquinone, 2-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthaquinone,
9,10-phenanthraquinone, 2-methyl-1,4-naphthaquinone, 2,3-dichloronaphthaquinone, 1,4-dimethylanthraquinone, 2,3-dimethylanthraquinone, 3-chloro-2-methylanthraquinone, 7,8,9,10-tetrahydrophthalcenequinone, etc., but other aromatic ketones such as benzophenone, Michler's ketone [4,4 ′
-Bis (dimethylamino) benzophenone] 4,4'-bis (diethylamino) benzophenone], 4-methoxy-4'-dimethylaminobenzophenone and the like. Other examples include benzoin and benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin phenyl ether, methylbenzoyl and ethylbenzoin. Furthermore, 2,4,5-triarylimidazole dimer and 2-mercaptobenzoxazole, leuco crystal violet, tris (4-diethylamino-
Combinations with 2-methylphenyl) methane and the like can also be used.

In addition, there are substituted or unsubstituted thioxanthones, such as 2-chlorothioxanthone, 2,4-diethylthioxanthone, and 2,4-dimethylthioxanthone. Further, a combination of these thioxanthones with an aliphatic or aromatic tertiary amine such as N-methyldiethanolamine, P-dimethylaminobenzoic acid ethyl ester and the like can be used, and a combination of thioxanthones with an alkylaminobenzophenone such as Michler's ketone can be used. Combinations of thioxanthones and oxime esters such as benzophenone oxime acetate are also effective. These addition-polymerizable initiators that can be activated by light may be used alone or in combination of two or more. The present invention is not limited to these.

These are 0.01 per 100 parts by weight of the thermoplastic polymer binder.
-30 parts by weight, preferably 0.1-15 parts by weight.

In the present invention, other stabilizers, dyes and the like, which are the above essential elements, can be added as required. Examples of the stabilizer include hydroquinone, hydroquinone monomethyl ether, t-butylcatechol and the like. These can be added within a range that does not inhibit the photopolymerization reaction. Also, a plasticizer for imparting appropriate flexibility can be added. For example, phthalic acid esters such as diethyl phthalate, dibutyl phthalate, diheptyl phthalate and dioctyl phthalate, fatty acid esters such as dioctyl adipate and dibutyl diglycol adipate, phosphoric acid esters such as trimethylphosphine and sulfone such as toluene sulfonic acid amide. Examples thereof include acid amides.

Further, a dye may be added to facilitate the visual discrimination of the photosensitive layer. Examples thereof include crystal violet, malachite green, Victoria blue, methylene blue and the like.

In the present invention, when the photopolymerization curable composition is solvent-free, a usual printing method or coating method is used, and when it is dissolved or dispersed in a solvent, it is coated or impregnated on a suitable support, and then, A photopolymer layer can be formed by evaporating the solvent. In this case, the support may be any one that does not adversely affect photopolymerization, and examples thereof include various plastics, various films, paper, glass, various metals, and ceramic products.

Such a photopolymer layer is cured by light from a suitable light source such as a low pressure mercury lamp or an ultrahigh pressure mercury lamp. The composition of the present invention can be used as a photopolymer or a photoresist when producing a printing plate, a printed substrate or the like.

〔Example〕

Next, the present invention will be specifically described with reference to examples. The present invention is not limited to the embodiment.

Example of Synthesis of Thermoplastic Polymer Binder A thermoplastic polymer binder solution was obtained by polymerizing the following addition-polymerized monomers.

Liquid A Methacrylic acid 250 g Methyl methacrylate 350 g 2-Phenoxyethyl acrylate 450 g Liquid B α, α′-azobis-iso-butyronitrile 5 g Tetrahydrofuran 250 g Dropping funnel containing liquids A and B, reflux condenser, nitrogen inlet pipe, 1000 in a 5 separable flask equipped with a stir bar.
g methyl ethyl ketone was added and heated to 75 ° C. Next, both liquids A and B were added dropwise over 3 hours, and stirring was continued while maintaining the temperature at 75 ° C for 8 hours. A clear resin solution was obtained.

Synthetic Comparative Example Attempts were made to polymerize the following addition-polymerizable monomers.

Liquid A Methacrylic acid 250 g N-butyl acrylate 350 g 2-Phenoxyethyl acrylate 450 g Liquid B α, α′-azobis-iso-butyronitrile 5 g Tetrahydrofuran 250 g Polymerization was attempted in the same manner as in Example 1, but the reaction liquid was obtained after the initiation of polymerization. It became cloudy and precipitated, and it could not be entangled with a stirring bar to obtain a uniform resin solution.

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

Copolymer of 25 wt% methacrylic acid, 35 wt% methyl methacrylate, 45 wt% 2-phenoxyethyl acrylate 50 g Trimethylolpropane triacrylate 30 g Benzophenone 1.5 g Michler's ketone 0.15 g Victoria blue 0.05 g Methyl ethyl ketone 80 g This is 25 μm thick It was coated on a polyethyl glycol terephthalate film support and dried at 75 ° C. to obtain a photosensitive film. The thickness of the photosensitive layer was 25 μm. This was laminated on a polished copper clad laminate with a rubber roller heated to 100 ° C. Place a wiring circuit pattern mask on it and irradiate it with an ultra-high pressure mercury lamp from a distance of 50 cm for 10 seconds. After curing, develop it with a 1% sodium carbonate aqueous solution at 30 ° C. to obtain a resin relief image on the copper clad laminate. It was

Next, copper was etched with an alkaline etchant to obtain a good printed wiring board.

Example 2 The following components were mixed to obtain a photopolymerization cured composition.

Copolymer of 25 wt% methacrylic acid, 45 wt% ethyl methacrylate and 35 wt% phenoxydiethoxy acrylate 50 g Trimethylolpropane triacrylate 30 g Benzophenone 1.5 g Michler's ketone 0.15 g Victoria blue 0.05 g Methyl ethyl ketone 80 g Evaluation similar to Example 1 As a result, a good printed wiring board was obtained.

Example 3 The following components were mixed to obtain a photopolymerization cured composition.

Copolymer of methacrylic acid 12 wt%, acrylic acid 8 wt%, propyl methacrylate 60 wt%, 2-phenoxyethyl acrylate 20 wt% 50 g Trimethylolpropane triacrylate 30
g 2-chlorothioxanthone 0.5
g Methyldiethanolamine 0.05
g Victoria Blue 0.05
g Methyl ethyl ketone 80
g As a result of evaluation as in Example 2, a good printed wiring board was obtained.

Comparative Example 1 The following components were mixed to obtain a photopolymerization / curing composition.

Copolymer of 25 wt% methacrylic acid, 38 wt% methyl methacrylate and 37 wt% n-butyl acrylate 50 g Trimethylolpropane triacrylate 30 g 2-Chlorthioxanthone 0.5 g Methyldiethanolamine 0.05 g Victoria blue 0.05 g Methylethylketone 80 g As in Example 2. However, disconnection was observed on the excellent printed wiring board.

Comparative Example 2 The following components were mixed to obtain a photopolymerization cured composition.

Copolymer of 25 wt% methacrylic acid, 47 wt% methyl methacrylate, 28 wt% 2-methoxyethyl acrylate 5
0 g Trimethylolpropane triacrylate 30 g 2-Chlorthioxanthone 0.5 g Methyldiethanolamine 0.05 g Methylethylketone 80 g Evaluation was made in the same manner as in Example 2, but the printed wiring board obtained had a break.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C08F 299/02 MRS 7442-4J G03F 7/038 501 H05K 1/03 7011-4E

Claims (2)

[Claims] 1. A carboxyl group-containing addition-polymerizable monomer (A) in an amount of 4 to 40% by weight and the following non-acidic addition-polymerized monomer (B) in at least 5% by weight and the following non-acidic addition 100 parts by weight of the thermoplastic polymer binder obtained by copolymerizing the polymerizing monomer (C) with the non-acidic addition polymerizing monomer (B): acrylic acid represented by the following general formula (I) At least one of ester or methacrylic acid ester monomer (R ₁ is a hydrogen atom or a methyl group, R ₂ is an alkylene group having 1 to 5 carbon atoms, R ₃ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom, and n is an integer of 1 to 20. ) Non-acidic addition-polymerizable monomer (C): at least one non-acidic addition-polymerizable monomer having a Q value and an e-value satisfying the following formula (II) (Q _A and e _A are Q value and e value of addition polymerization monomer (A), and Q _C and e _C are Q value and e value of addition polymerization monomer (C)) (2) 50 at normal pressure Addition-polymerizable compounds having a boiling point of ℃ or higher 10
To 200 parts by weight, and (3) a photoinitiator and / or 0.01 to 30 parts by weight of a photoinitiator system, a photopolymerizable curable composition. 2. An addition polymerization monomer having a carboxyl group
The photopolymerizable composition according to claim 1, wherein (A) is methacrylic acid alone or a mixture of methacrylic acid and acrylic acid.