JPS628141A - Photopolymerizable composition - Google Patents

Abstract

PURPOSE:To remarkably improve the conservative stability of the titled composition, even if a photopolymerization initiator as well as a color coupler are incorporating to the titled composition by incorporating an oxalic acid and/or its salt to a conventional photopolymerizable composition. CONSTITUTION:The titled composition is comprised (A) 30-100pts.wt. compd. having at least one of an ethylenic unsatd. group, and (B) 0-70pts.wt. thermoplastic org. polymer on the 100pts.wt. components (A) and (B), and (C) 0.1-10pts. wt. compd. contg. the group shown by the formula (C) on the 100pts.wt. components (A) and (B), and (D) 1-20pts.wt. compd. capable of forming a radical by forming a complex with the component (C) with an active ray, (E) 0.1-5pts.wt. leuco dyestuff, (F) 0.1-5pts.wt. a halogen compd. and (G) 0.01-20 pts.wt. oxalic acid and or its salt. The boiling points of each components (A)-(F) are >=100 deg.C at a room temp.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a photopolymerizable composition, and more particularly to a photopolymerizable composition with improved stability during storage.

(Prior art) Current printed wiring boards are made by providing a layer of a photopolymerizable composition on the surface of a copper-clad laminate, washing off the unexposed areas by image exposure and development, and then exposing the board after obtaining a photocured image. It is manufactured by a method in which the copper is removed by etching and then the photocured image is peeled off, or a different metal is plated on the exposed copper portion, the photocured image is peeled off and the exposed body portion is etched, etc. There is. The photopolymerizable composition is widely used as such etching photoresists or plating photoresists. It is used by coating and drying on a clad laminate, or by coating and drying on a film such as a polyester film and then hot-pressing onto a copper-clad laminate.

Conventionally, in order to increase the curing speed by irradiation with actinic rays and achieve high photosensitivity, a photopolymerizable composition consisting of a compound having an ethylenically unsaturated group was formed with an amino compound and a complex with the amino compound by irradiation with actinic rays. It is known to add photoinitiator systems consisting of compounds that generate radicals. For example, using a combination of an aromatic ketone such as aminophenyl ketone and a 2.4°5-triaryl imidazole dimer (Japanese Patent Publication No. 48-38403, U.S. Pat. No. 731,733), Use of a combination with a methylene compound (Special public interest
No. 9-11936, US Pat. No. 877,853) are known.

It is also known to add a coloring agent system consisting of a leuco dye and a halogen compound to the photopolymerizable composition in order to clearly distinguish the area irradiated with actinic rays. For example, Spragg et al., US Pat. No. 3,113,024, describes the addition of a color former system consisting of a leukotriphenylmethane dye and a halogenated sulfone.

However, when the photoinitiator system and the color former system are simultaneously blended as a photopolymerizable composition, there is a problem in that the storage stability decreases, especially when stored as a festival. It is stable, with the drawback of discoloration and gelation.

(Problems to be Solved by the Invention) An object of the present invention is to eliminate the drawbacks of the prior art and provide a photopolymerizable composition with excellent storage stability.

(Means for Solving the Problems) As a result of various studies to achieve the above object, the present inventors added oxalic acid and/or
Alternatively, the inventors have discovered that storage stability can be significantly improved by incorporating cyfusate, even when a photoinitiator system and a color former system are simultaneously incorporated, and have thus arrived at the present invention.

The present invention comprises (A) 30 to 100 parts by weight of a compound having at least one ethylenically unsaturated group and (B) 0.0 parts by weight of a thermoplastic organic polymer. ~70 parts by weight of (A) and (B)
The total amount of (A) and (B) is 100 parts by weight.
0.1 to 10 parts by weight (each independently means hydrogen atom or lower alkyl group) per 100 parts by weight of (
D) 1 to 20 parts by weight of a compound that forms a complex with component C to generate radicals when exposed to actinic rays, (E) 0.1 to 5 parts by weight of a leuco dye, and (F) 0.1 to 5 parts by weight of a halogen compound.
parts by weight and (G) 0.01 to 20 parts by weight of oxalic acid and/or oxalate, and components (A) to (F
) The photopolymerizable composition has a boiling point of each component of 100° C. or higher at normal pressure.

Examples of the compound having at least one ethylenically unsaturated group (component A) used in the photopolymerizable composition of the present invention include a compound obtained by adding an α,β-unsaturated carboxylic acid to a polyhydric alcohol. , such as tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolbrobandi(
meth)acrylate, trimethylolpropane tri(
meth)acrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethanetetra(meth)acrylate, polybropylene glycol di(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc. , α, β- to glycidyl group-containing compounds
Compounds obtained by adding unsaturated carboxylic acids, such as trimethylolpropane triglycidyl ether triacrylate, bisphenol A diglycidyl ether diacrylate, etc., and polyhydric carboxylic acids, such as phthalic anhydride, with hydroxyl groups and ethylenically unsaturated groups. esters with substances such as β-hydroxyethyl (meth)acrylate, alkyl esters of acrylic acid or methacrylic acid, such as methyl (meth)acrylate,
Examples include ethyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. These are 2 if necessary.
More than one species may be used.

The blending amount of component (A) is 30 to 10 parts when the total amount of component (B) and component (A) described below is 100 parts by weight.
0 parts by weight, preferably 40 to 70 parts by weight. If the blending amount is less than 30 M parts, the photocured product will be brittle and sufficient physical properties will not be obtained.

Examples of the thermoplastic organic polymer (component (B)) include (
Copolymers of meth)acrylic acid alkyl esters and (meth)acrylic acid, copolymers of (meth)acrylic acid alkyl esters, (meth)acrylic acid, and vinyl monomers copolymerizable with these, and the like are used. Examples of the (meth)acrylic acid alkyl ester include (meth)acrylic acid methyl ester, (meth)acrylic acid ethyl ester, (meth)acrylic acid butyl ester, (meth)acrylic acid 2-ethylhexyl ester, and the like. In addition, (meth)acrylic acid alkyl esters and vinyl monomers that can be copolymerized with (meth)acrylic acid include (meth)acrylic acid tetrahydrofurfuryl ester, (meth)acrylic acid dimethylethyl ester, and (meth)acrylic acid diethyl ester. , methacrylic acid glycidyl ester, 2.2.2-)lifluoroethyl (meth)acrylate, 2.2.3.3-tetrafluoropropyl (meth)acrylate acrylamide, diacetone acrylamide, styrene, vinyltoluene, etc. . In addition to homopolymers and copolymers of the above-mentioned compounds, the thermoplastic organic polymer component (B)) includes copolyesters obtained using terephthalic acid, isophthalic acid, or sebacic acid as the acid component, and lji combinations of butadiene and acrylonitrile. , cellulose acetate, cellulose acetate butyrate, methyl cellulose, ethyl cellulose, etc. can also be used. Use of these thermoplastic organic polymers improves coating properties and the film strength of the resulting cured product.

The blending amount of component (B) is 0 to 70 parts by weight, preferably 30 to 60 parts by weight, when the total amount of component (A) and component (B) is 100 parts by weight. When this amount is more than 70 parts by weight, photosensitivity decreases.

Further, the weight average molecular weight of this thermoplastic organic polymer is preferably 10.000 or more from the viewpoint of coating properties and film strength.

These component (A) and component (B) are used in such an amount that the total amount of both components is 100 parts by weight.

Examples of the group-containing compound (component (C)) include p-aminophenyl represented by - (wherein R1 and R2 each independently represent a hydrogen atom or a lower alkyl group, and R3 means a group -0R4 or an alkyl group). Ketones are mentioned. Specific examples of these compounds include, for example, 4,41
-bis(dimethylamino)benzophenone [Michler's ketone], 4,41-bis(diethylamino)benzophenone, dimethylaminobenzoic acid ethyl ester, dimethylaminobenzoic acid butyl ester, dimethylaminobenzoic acid isoamyl ester, and the like.

In addition to the compound represented by the general formula (I), component (C) may include, for example, di(n-propyl)amine and triamine.
Amines such as (n-butyl)amine, triamylamine, propylene diamine, and aniline are used.

The blending amount of component (C) is 0.1 to 10 parts by weight, preferably 1.0 to 7 parts by weight, based on 100 parts by weight of the total amount of components (A) and (B). If this amount is less than 0.1 part by weight, a practical photocuring rate cannot be obtained, and if it is more than 10 parts by weight, stability may decrease or the curing of the bottom of the resist may not proceed. There are cases.

Compound (
Examples of component (D) include benzophenone, 2-chlorothioxanthone, 2°4-diethylthioxanthone, and 2-propylthioxanthone.

The blending amount of component (D) is 1 to 20 parts by weight, preferably 2 to 10 parts by weight, based on 100 parts by weight of the total amount of components (A) and (B). If this amount is less than 1 part by weight, a practical photocuring speed may not be obtained, or 20 parts by weight.
If the amount is more than 1 part by weight, the stability may decrease or the curing of the bottom portion of the resist may not progress.

Preferred combinations of component (C) and component (D) include, for example, 4.41-bis(dimethylamino)benzophenone/benzophenone, 4.4'-bis(diethylamino)benzophenone/benzophenone, and dimethylaminobenzoic acid ethyl ester. /2,4-diethylthioxanthone, dimethylaminobenzoic acid isoamyl ester/2
．． Examples include 4-diethylthioxanthone, dimethylaminobenzoic acid isoamyl ester/2-propylthioxanthone, and the like.

Examples of the leuco dye (component (E)) used in the photopolymerizable composition of the present invention include tris(4-dimethylamino-2-methylphenyl)methane [leuco crystal violet], tris(4-diethylamino-2- Examples include methylphenyl)methane leucomalachite green.

The blending amount of component (E) is 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight, based on 100 parts by weight of the total amount of components (A) and (B). If this amount is less than 0.1 part by weight, sufficient color development will not be achieved by irradiation with actinic rays, and if it is more than 5 parts by weight, stability will be reduced.

The halogen compound used in the photopolymerizable composition of the present invention (
Component (F)) releases halide free radicals by irradiation with actinic rays and causes the leuco dye of component (E) to develop color. For example, amyl bromide, isoamyl bromide, isobutylene bromide, ethylene bromide, Diphenylmethyl bromide, benzal bromide, methylene bromide, tribromomethylphenylsulfone, carbon tetrabromide, tris(2,3-dibromopropyl) phosphate, trichloroacetamide, amyl iodide, isobutyl iodide, 1,1. 1-) Lichloro-
Examples include 2,2-bis(p-chlorophenyl)ethane, hexachloroethane, methyl methacrylate-tribromophenyl acrylate copolymer, methyl methacrylate-dibromopropyl acrylate copolymer, and the like.

The blending amount of component (F) is 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight, based on 100 parts by weight of the total amount of components (A) and (B). If this amount is less than 0.1 part by weight, sufficient color development will not be achieved by irradiation with actinic rays, and if it is more than 5 parts by weight, stability will be reduced.

Preferred combinations of component (E) and component (F) include, for example, leuco crystal violet/carbon tetrabromide,
Leuco Crystal Violet/Tribromomethylphenylsulfone, Leuco Crystal Violet/1.
1.1-) Lichloro2.2-bis<p-chlorophenyl)ethane, tris(4-diethylamino-2-methylphenyl)methane/carbon tetrabromide, tris(4-diethylamino-2-)1. Tylphenyl)methane/tribromomethylphenylsulfone, tris(4-diethylamino-2-methylphenyl)methane/1°1.1-trichloro-2,2-bis(p-chlorophenyl)ethane, and the like.

The photopolymerizable composition of the present invention contains oxalic acid and/or oxalate (component (G)) to improve storage stability.
) is used. As the oxalate, for example, malachite green oxalate, sodium oxalate, potassium oxalate, ammonium chelate, etc. are used.

The blending amount of component (G) is 0.01 to 20 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the total amount of component (A) and component (B). This amount is 0.01
If it is less than 2 parts by weight, it will not be able to maintain sufficient stability during storage, and if it is more than 2 parts by weight, it will not be sufficiently dispersed in the photopolymerizable composition.

The photopolymerizable composition of the present invention can contain a thermal polymerization inhibitor such as p-methoxyphenol, hydroquinone, pyrogallol, naphthylamine, phenothiazine, and t-butylcatechol.

Further, the photopolymerizable composition of the present invention may contain colorants such as dyes and pigments. Examples of colorants include tsukusin, auramine base, crystal violet, Victoria pia blue, malachite green, methyl orange, Ashidoviolets) RRH etc. are used.

Furthermore, known additives such as plasticizers, adhesion promoters, and talc may be added to the photopolymerizable composition of the present invention.

Each component (A) to (F) of the photopolymerizable composition must all have a boiling point of 100° C. or higher at normal pressure. If the boiling point of each of these components is lower than 100° C., the varnish of the photopolymerizable composition will volatilize during drying after being applied onto the support.

The photopolymerizable composition of the present invention combines the components A to G with a solvent for dissolving them, such as toluene, acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone,
Methyl cellosolve, ethyl cellosolve, chloroform,
A uniform varnish can be obtained by dissolving and mixing in methylene chloride, methyl alcohol, ethyl alcohol, etc.

The photopolymerizable composition of the present invention can be used by applying it as it is to a substrate such as a copper plate, drying it, exposing it to actinic rays, and photocuring it. Alternatively, the varnish may be applied onto a film such as a polyester terephthalate film, dried, and then laminated onto a substrate and photocured for use.

The active light source used for photocuring is wavelength 3.
A material that emits light of 00 to 450 nm is used, and preferred examples include mercury vapor arc, carbon arc, and xenon arc.

(Effects of the Invention) Although the photopolymerizable composition of the present invention simultaneously contains a photoinitiator system to achieve high photosensitivity and a color former system to clarify the area irradiated with actinic rays, , and has excellent storage stability.

The photopolymerizable composition of the present invention can be used as a photoresist for etching or plating, for example, by using a photocured film as a relief, or by using a copper-clad laminate as a substrate.

(Example) The present invention will be explained below with reference to Examples.

Examples 1 to 6 40.0% by weight methyl cellosolve of methyl methacrylate/methacrylic acid/2-ethylhexyl acrylate (weight ratio 60/20/20) copolymer (weight average molecular weight 80,000) 130 g of solution (polymer component 52
g), 10g of tetraethylene glycol diacrylate
, poly(p#5)oxyethylated bisphenol A
dimethacrylate (BPE manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)
-10>30g, Leuco Crystal Violet 1.0
A solution (t
) 192.1 g (total nonvolatile content 94.1 g, nonvolatile content concentration 49.0% by weight) was obtained.

Next, each component shown in Table 1 was added to this solution (I) to obtain a photopolymerizable composition of the present invention (the unit in Table 1 is g).

This composition was stored in a dark place at 23° C., and the stability of the varnish was evaluated by checking the number of days until discoloration and gelation occurred. The results are shown in Table 1.

In the table, the symbol 0 means that there is no abnormality, Δ means that discoloration or thickening is observed, and × means that gelation is observed.

Comparative Examples 1 to 4 Each component shown in Table 1 was added to solution (I) and treated in the same manner as in Example 1 to obtain a photopolymerizable composition. Table 1 shows the results of evaluating the stability of

Below margin

Claims (1)

[Claims] 1. (A) 30 to 100 parts by weight of a compound having at least one ethylenically unsaturated group and (B) 0 to 70 parts by weight of a thermoplastic organic polymer, (A) and (B) ), and 100 parts by weight of (A) and (B).
(C) ▲ Numerical formulas, chemical formulas, tables, etc. ▼ 0.1 to 10 parts by weight of a group-containing compound (R_1 and R_2 each independently mean a hydrogen atom or a lower alkyl group) to parts by weight, (
D) 1 to 20 parts by weight of a compound that forms a complex with component C to generate radicals when exposed to actinic rays, (E) 0.1 to 5 parts by weight of a leuco dye, and (F) 0.1 to 5 parts by weight of a halogen compound.
parts by weight and (G) 0.01 to 20 parts by weight of oxalic acid and/or oxalate, and components (A) to (F
) A photopolymerizable composition in which the boiling point of each component is 100°C or higher at normal pressure.