JP2007206421A - Photosensitive resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition which can satisfy both alkali developability and photocurability and which will not cause warpage of a substrate at curing, because of small shrinkage due to curing. <P>SOLUTION: The photosensitive resin composition capable of forming an alkali developable film contains an acid modified vinyl ester, having a bisphenol S skeleton and an alkylene glycol chain. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a photosensitive resin composition useful for image formation.

  The photosensitive resin composition for image formation is capable of microfabrication by applying the principle of photolithography (photolithography) and can form an image by giving a cured product having excellent physical properties. It is widely used for various resist materials and printing plates. There are a solvent development type and an alkali development type in this photosensitive resin composition for image formation, but in recent years, an alkali development type that can be developed with a dilute weak alkaline aqueous solution has become mainstream from the viewpoint of environmental measures. Alkali-developable photosensitive resin compositions are also used in printed wiring board production, liquid crystal display board production, printing plate making and the like.

  When the photosensitive resin composition for image formation is used in a photolithography process as a resin composition for a liquid development type solder resist, for example, the resin composition is first applied on a substrate, and then dried by heating. A series of steps is employed in which after forming a coating film, a film for forming a pattern is attached to the coating film, exposed, and developed. In such a process, if adhesiveness remains in the coating film after drying by heating, a part of the resist adheres to the pattern forming film after peeling, and an accurate pattern cannot be reproduced. There was a problem that the forming film could not be peeled off. For this reason, tack-free property after coating film formation is an important required characteristic of a liquid development type resist.

  In addition, photosensitivity during exposure and developability after exposure are also important required characteristics. That is, in order to form a fine pattern with high reliability and good reproducibility, during development, a portion cured by exposure must not be eroded by the developer, and conversely, an unexposed portion can be promptly developed during development. Must be removed.

  Furthermore, for the cured part, characteristics related to long-term reliability such as heat resistance, water resistance, moisture resistance, etc. that can withstand high processing conditions (soldering process in the case of solder resist, etc.) are required. ing.

  Carboxyl group-containing epoxy (meth) acrylate in which a carboxyl group is introduced by reacting an acid anhydride with an epoxy (meth) acrylate obtained by reacting an epoxy resin with (meth) acrylic acid to satisfy the above characteristics to some extent. Is known (for example, Patent Documents 1 and 2). This carboxyl group-containing epoxy (meth) acrylate satisfies a balanced balance of tack-free properties, photosensitivity, and developability, and compares important properties such as heat resistance and water resistance required for cured products. Good. However, with the advancement of technology, higher-level characteristics, for example, as the pattern becomes finer and the electronic devices become smaller, lighter, and more functional, there is a demand for a thinner overall thickness while multilayering the printed circuit board. It is required to respond to.

In the case of a solder resist, as described above, a process such as after-curing or soldering at a high temperature is performed on a cured portion after development. However, when the substrate is thinned, the solder resist is cured during such high-temperature processing. There is a problem that the entire substrate is warped by shrinkage.
In the case of the above-mentioned epoxy (meth) acrylate, the cured coating film properties such as heat resistance are excellent, and there is no problem when used for a relatively thick substrate, but application to a thin plate is difficult. On the other hand, as a solder resist with a small warp at the time of curing, it can be used for a flexible printed wiring board, a reaction product of polyfunctional epoxy compound of bisphenol F or bisphenol A type and unsaturated monocarboxylic acid, polybasic A solder resist made of an acid-modified epoxy acrylate to which an acid anhydride has been added has been proposed (Patent Document 3). However, in this case, there is room for improvement in terms of heat resistance and the like. Furthermore, a technique using a mixture of a bisphenol-type carboxyl group-containing epoxy (meth) acrylate and a novolac-type carboxyl group-containing epoxy (meth) acrylate is also disclosed (Patent Document 4), but is also applied to a flexible wiring board. There was room for improvement in terms of heat resistance, etc., as much as possible.

JP-A 61-243869 JP 63-258975 A JP-A-5-32746 JP 2000-109541 A

  Therefore, in the present invention, the sensitivity at the time of exposure and the alkali developability can be made compatible, and further, the shrinkage in curing is small in the heat treatment step after pattern formation, and the substrate is used when applied to a substrate like a solder resist. An object of the present invention is to provide a photosensitive resin for image formation that gives a cured product that does not cause warping.

This invention which solved the said subject makes it 1st summary to be the photosensitive resin composition characterized by containing the acid modified vinyl ester which has bisphenol S frame | skeleton and an alkylene glycol chain | strand. Next, the acid-modified vinyl ester comprises a bifunctional epoxy compound, a bifunctional phenol compound, an unsaturated monomer having a functional group capable of reacting with an unsaturated monobasic acid and / or a phenolic hydroxyl group, A second gist is that synthesized from a basic acid anhydride and using a bifunctional epoxy compound or a bifunctional phenol compound having a bisphenol S skeleton as at least a part thereof. The third gist is that at least a part of the bifunctional epoxy compound has an alkylene glycol chain.
The present invention is described in detail below.

  The photosensitive resin composition of the present invention contains an acid-modified vinyl ester having a bisphenol S skeleton and an alkylene glycol chain. The acid-modified vinyl ester includes a bifunctional epoxy compound, a bifunctional phenol compound, an unsaturated monomer having a functional group capable of reacting with an unsaturated monobasic acid and / or a phenolic hydroxyl group, and a polybasic acid anhydride. Obtained by using a bifunctional epoxy compound or a bifunctional phenol compound having a bisphenol S skeleton, and a bifunctional epoxy compound having an alkylene glycol chain in at least a part. It is done.

  Usually, a vinyl ester is obtained by reacting a carboxyl group of an unsaturated monobasic acid with an epoxy group in an epoxy compound, and this reaction introduces a double bond that becomes a crosslinking point at the time of curing. In contrast, in the present invention, a vinyl ester having a double bond distance longer than the distance between epoxy groups of the starting epoxy compound is synthesized, and this vinyl ester is used as one composition of the photosensitive resin composition. It is. If the distance between the double bonds is increased, flexibility can be imparted to the cured product, but there is a concern that the glass transition temperature is lowered and the heat resistance is impaired due to a decrease in the crosslinking density, but in the present invention, bisphenol S is contained in the vinyl ester. By introducing the skeleton, heat resistance is not impaired by the aggregation effect due to intermolecular interaction, and good alkali developability is exhibited by the presence of the alkylene glycol chain. In addition to reconciling these conflicting properties at a high level, surprisingly, by having both the bisphenol S skeleton and the alkylene glycol chain, the shrinkage of the cured coating during heat treatment is extremely small, and the substrate is thin. It has been found that the warpage can be reduced even when using.

  That is, the acid-modified vinyl ester in the present invention has a bisphenol S skeleton and an alkylene glycol chain, and reacts with a bifunctional epoxy compound, a bifunctional phenol compound, an unsaturated monobasic acid and / or a phenolic hydroxyl group. A difunctional epoxy compound or a bifunctional phenol compound having a bisphenol S skeleton, and an alkylene in at least a part of the bifunctional epoxy compound. It is obtained by using one having a glycol chain.

  First, a bifunctional phenol compound will be described as a first raw material for the vinyl ester in the present invention.

When obtaining the acid-modified vinyl ester of the present invention, it is essential to use at least one of a bifunctional epoxy compound or a bifunctional phenol compound having a bisphenol S skeleton at least in part. Accordingly, when only the bifunctional epoxy compound having no bisphenol S skeleton is used, the bifunctional phenol compound having at least a part of the bisphenol S skeleton is used. Examples of the phenol compound having such a bisphenol S skeleton include bisphenol S, tetrabromobisphenol S, tetramethylbisphenol S and the like, and one or a combination of two or more can be used. Among these, bisphenol S is preferable because it is easily available.
Moreover, you may use together the well-known phenolic compound which does not have bisphenol S frame | skeleton as a bifunctional phenolic compound, As such a phenolic compound, bisphenol A, bisphenol F, 9,9-bis (4-hydroxyphenyl) Known bisphenols excluding bisphenol S such as fluorene and bis (4-hydroxyphenyl) sulfide, biphenols and the like can be mentioned. Furthermore, a trifunctional or higher functional phenol compound may be used in combination, and examples thereof include novolak resin and 1,1,1-tris (4-hydroxyphenyl) ethane.
Here, when the phenol compound not having a bisphenol S skeleton is used in combination, the amount used is preferably 75 mol% or less when the entire phenol compound is 100 mol%. When it exceeds 75 mol%, the aggregation effect derived from the bisphenol S skeleton is insufficient, and the heat resistance of the cured product may not be sufficiently obtained. The more preferable usage amount of the phenol compound having no bisphenol S skeleton is 50 mol% or less, and the more preferable usage amount is 25 mol% or less.
Next, a bifunctional epoxy compound will be described as a second raw material for the acid-modified vinyl ester in the present invention.

  As in the case of the above-mentioned phenol compound, when only a bifunctional phenol compound having no bisphenol S skeleton is used, a bifunctional epoxy compound having at least a part of the bisphenol S skeleton is used. Examples of such an epoxy compound having a bisphenol S skeleton include those obtained by reacting a phenol compound having the bisphenol S skeleton with an epihalohydrin such as epichlorohydrin or epibromohydrin under known conditions, or the bisphenol S skeleton described above. It is possible to use a compound obtained by reacting an ethylene oxide or propylene oxide with a phenol compound having an epihalohydrin (having both a bisphenol S skeleton and an alkylene glycol chain), and combining one or more of these Can be used. Among these, bisphenol S type epoxy obtained by reacting bisphenol S and epichlorohydrin is preferable because it is easily available.

  When using a bifunctional epoxy compound having a bisphenol S skeleton but no alkylene glycol chain, at least part of the bifunctional epoxy compound having no bisphenol S skeleton has an alkylene glycol chain. It will be used indispensable. Examples of such an epoxy compound having an alkylene glycol chain include those obtained by reacting a known phenol compound having no bisphenol S skeleton with ethylene oxide or propylene oxide and then reacting with epihalohydrin, or hydrogenated products thereof. Or a diglycidyl ether type epoxy resin of a polyhydric alcohol.

  Among these, since the characteristics of the cured coating film such as heat resistance are good, it is preferable to use a phenol compound obtained by reacting an ethylene oxide or propylene oxide with an epihalohydrin.

Further, a known epoxy compound having neither a bisphenol S skeleton nor an alkylene glycol chain may be used in combination as the bifunctional epoxy compound. Examples of such an epoxy compound include bisphenol A type, tetrabromobisphenol A type, and bisphenol F type. Bisphenol type epoxy resins; alicyclic epoxy resins; diglycidyl ester type epoxy resins; diglycidyl amine type epoxy resins; biphenyl type epoxy resins; phenylene type epoxy resins.
Furthermore, a trifunctional or higher functional epoxy compound may be used in combination. Examples thereof include polyfunctional glycidylamine resins such as tetraglycidylaminodiphenylmethane; polyfunctional glycidyl ether resins such as tetraphenylglycidyl ether ethane; phenol A novolak-type epoxy resin or a cresol novolak-type epoxy resin; a polyphenol compound obtained by a condensation reaction of a phenol compound such as phenol, o-cresol, m-cresol, or naphthol with an aromatic aldehyde having a phenolic hydroxyl group; and epichlorohydrin, A reaction product of a phenol compound and a polyphenol compound obtained by addition reaction of a diolefin compound such as divinylbenzene or dicyclopentadiene with epichlorohydrin; 4-vinyl Those obtained by epoxidizing a ring-opening polymerization of cyclohexene-1-oxide with a peracid; epoxy resin having a heterocyclic ring such as triglycidyl isocyanurate; etc known epoxy compounds.
Here, when the epoxy compound having neither a bisphenol S skeleton nor an alkylene glycol chain is used in combination, the amount used is preferably 75 mol% or less when the entire epoxy compound is 100 mol%. When it exceeds 75 mol%, the effects derived from the bisphenol S skeleton and the alkylene glycol chain are insufficient, and the heat resistance and alkali developability may be impaired, and the warp reduction effect may not be exhibited. The more preferable usage amount of the epoxy compound having neither the bisphenol S skeleton nor the alkylene glycol chain is 50 mol% or less, and the more preferable usage amount is 25 mol% or less.
An unsaturated monomer having a functional group capable of reacting with an unsaturated monobasic acid and a phenolic hydroxyl group, which is the third raw material of the acid-modified vinyl ester in the present invention, is a radically polymerizable unsaturated diester in the vinyl ester. Unsaturated monomer used to introduce a heavy bond and having a functional group capable of reacting with an unsaturated monobasic acid when reacting with an epoxy group and reacting with a phenolic hydroxyl group when reacting with a phenolic hydroxyl group Is used.

  The unsaturated monobasic acid to be reacted with the epoxy group is a monobasic acid having one carboxyl group and one or more radically polymerizable unsaturated bonds. Specific examples include acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, β-acryloxypropionic acid, hydroxyalkyl (meth) acrylate having one hydroxyl group and one (meth) acryloyl group, and dibasic acid anhydride. Reaction products, reaction products of polyfunctional (meth) acrylates having two hydroxyl groups and two or more (meth) acryloyl groups with dibasic acid anhydrides, caprolactone modified products of these monobasic acids, etc. 1 type, or 2 or more types can be used. Among them, preferred are those having a (meth) acryloyl group such as acrylic acid and methacrylic acid.

  The monomer reacted with a phenolic hydroxyl group is a compound having a functional group capable of reacting with one phenolic hydroxyl group and one or more radically polymerizable unsaturated bonds. Examples of functional groups capable of reacting with phenolic hydroxyl groups include isocyanate groups, vinyl ether groups, epoxy groups, oxazoline groups, aziridine groups, oxetanyl groups, and specific examples of monomers include isocyanate ethyl (meth) acrylate. , (Meth) acrylic acid 2- (vinyloxyethoxy) ethyl, glycidyl (meth) acrylate, allyl glycidyl ether, 2-isopropenyl-2-oxazoline, N- (meth) acryloylaziridine, etc. Species or two or more can be used.

The synthesis reaction of the vinyl ester of the present invention (before reaction with polybasic acid anhydride)
-A method of synthesizing a batch of unsaturated monomers having a functional group capable of reacting with a bifunctional phenolic compound, a bifunctional epoxy compound, an unsaturated monobasic acid and / or a phenolic hydroxyl group,
A method in which a chain extension reaction with a bifunctional phenol compound and a bifunctional epoxy compound is performed first, and then an unsaturated monomer having a functional group capable of reacting with an unsaturated monobasic acid and / or a phenolic hydroxyl group is reacted;
Unsaturated monomer having a functional group capable of reacting with a phenolic hydroxyl group with respect to the remaining phenolic hydroxyl group after first reacting the bifunctional phenolic compound, the bifunctional epoxy compound and the unsaturated monobasic acid Or a reaction of an unsaturated monomer having a functional group capable of reacting with a bifunctional phenol compound, a bifunctional epoxy compound and a phenolic hydroxyl group, and then reacting with the remaining epoxy group. A method of reacting a saturated monobasic acid,
Any method may be adopted.

In any of these methods, the functional group in the unsaturated monomer having an epoxy group in the bifunctional epoxy compound or a functional group capable of reacting with the epoxy group in the epoxy compound and the phenolic hydroxyl group is used. The total of phenolic hydroxyl groups in the bifunctional phenolic compound or phenolic hydroxyl groups in the phenolic compound and carboxyl groups in the unsaturated monobasic acid is 0.8 to 1.2 equivalents per 1 equivalent in total. It is preferable to prepare and react as described above.
The double bond equivalent of the vinyl ester obtained by the above method (molecular weight per chemical equivalent of radical polymerizable double bond) is preferably 450 g / eq or more and 7000 g / eq or less. If it is lower than 450 g / eq, the distance between cross-linking points is too short, and the warp reduction effect may not be sufficiently exhibited. A more preferred lower limit is 600 g / eq, and a more preferred lower limit is 750 g / eq. On the other hand, when the molecular weight exceeds 7000 g / eq, the molecular weight becomes too large, so that sufficient fluidity cannot be obtained even in the presence of a diluent such as a radical-polymerizable monomer or solvent described later, and handling is difficult during manufacturing and coating operations. It can be difficult. More preferably, it is 6000 g / eq, and a more preferable upper limit is 5000 g / eq.

  Vinyl ester synthesis reaction conditions are not particularly limited, but in the presence or absence of diluents such as radical polymerizable monomers and solvents described below, polymerization inhibitors such as hydroquinone and oxygen, tertiary amines such as triethylamine, and triethylbenzyl Quaternary ammonium salts such as ammonium chloride, imidazole compounds such as 2-ethyl-4-methylimidazole, tertiary phosphines such as triphenylphosphine, quaternary phosphonium salts such as benzyltriphenylphosphonium bromide, metal organic acids or inorganic salts Or what is necessary is just to perform at 80-150 degreeC normally in coexistence of reaction catalysts, such as a chelate compound.

  According to the above, a vinyl ester having a bisphenol S skeleton and an alkylene glycol chain is obtained. This vinyl ester is an unsaturated monomer having an epoxy group as a functional group capable of reacting with a bifunctional epoxy compound or a phenolic hydroxyl group. Is used, it has an alcoholic hydroxyl group produced by ring-opening by reaction of an epoxy group of these with a phenolic hydroxyl group or an unsaturated monobasic acid. A book that can be alkali-developed by making an acid-modified vinyl ester in which a carboxyl group is introduced by addition reaction of these hydroxyl groups with a polybasic acid anhydride that is the fourth raw material of the acid-modified vinyl ester in the present invention. The photosensitive resin of the invention is obtained. Polybasic acid anhydrides include phthalic anhydride, succinic anhydride, octenyl succinic anhydride, pentadodecenyl succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, 3,6- Reaction of endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, tetrabromophthalic anhydride, 9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide with itaconic anhydride or maleic anhydride Dibasic acid anhydrides such as products; trimellitic anhydride; biphenyl tetracarboxylic dianhydride, naphthalene tetracarboxylic dianhydride, diphenyl ether tetracarboxylic dianhydride, butane tetracarboxylic dianhydride, cyclopentane tetracarbo Acid dianhydride, pyromellitic acid anhydride, aliphatic such as benzophenone tetracarboxylic acid dianhydride or aromatic tetracarboxylic acid dianhydride and the like, may be used alone or two or more of them.

  The solvent for the addition reaction is not particularly limited, and any solvent that can be used for vinyl ester synthesis can be used. Industrially, following the synthesis of vinyl ester, it is convenient to carry out an addition reaction by adding a polybasic acid anhydride to the reaction solution.

  A catalyst may be used in the addition reaction as necessary. Specific catalysts include tertiary amines such as triethylamine, quaternary ammonium salts such as triethylbenzylammonium chloride, imidazole compounds such as 2-ethyl-4-methylimidazole, phosphorus such as triphenylphosphine and tetraphenylphosphonium bromide. Examples thereof include a compound, a carboxylic acid metal salt such as lithium acetate, and an inorganic metal salt such as lithium carbonate.

  The polybasic acid anhydride is preferably reacted so that the acid anhydride group in the polybasic acid anhydride is 0.1 to 1.1 mol with respect to 1 chemical equivalent of the hydroxyl group in the vinyl ester. More preferably, it is 0.2-0.9 mol. In order to develop good alkali developability even in a weak alkaline aqueous solution, the acid value of the acid-modified vinyl ester is preferably 30 mgKOH / g or more, and a more preferred lower limit is 50 mgKOH / g. Moreover, a preferable upper limit is 150 mgKOH / g, and a more preferable upper limit is 120 mgKOH / g. About reaction temperature, Preferably it is 60-150 degreeC, More preferably, it is 80-120 degreeC.

  In the present invention, a resin composition constituted with an acid-modified vinyl ester and a radical polymerizable compound such as epoxy acrylate described later can be used as an alkali-developable photosensitive resin composition for image formation. An acid-modified vinyl ester having an increased amount of radical-polymerizable unsaturated bonds, obtained by reacting a hydroxyl group and / or carboxyl group possessed by a monomer having a functional group capable of reacting with these groups, is used. You can also.

Examples of the functional group capable of reacting with a hydroxyl group and / or a carboxyl group include an isocyanate group, a vinyl ether group, an epoxy group, an oxazoline group, an aziridine group, and an oxetanyl group. Specific examples of the monomer include isocyanate ethyl ( (Meth) acrylate, (meth) acrylic acid 2- (vinyloxyethoxy) ethyl, glycidyl (meth) acrylate, allyl glycidyl ether, 2-isopropenyl-2-oxazoline, N- (meth) acryloylaziridine, etc. 1 type (s) or 2 or more types can be used.
When the hydroxyl group and the monomer are reacted, the reaction can be performed at any stage before or after the reaction with the polybasic acid anhydride. The reaction conditions between the hydroxyl group and / or carboxyl group and the monomer may be determined by appropriately selecting the catalyst and reaction temperature for each functional group by a known method.

  The amount of the monomer used relative to the hydroxyl group and / or carboxyl group should be such that the functional group capable of reacting with these in the monomer is 0.9 mol or less, more preferably 0.8 mol or less. Is preferred.

  In addition, when the monomer is reacted with the carboxyl group of the acid-modified vinyl ester, the carboxyl group is consumed, so that the acid value of the acid-modified vinyl ester obtained by increasing the amount of the radical polymerizable unsaturated bond is It is preferable to adjust the composition of the acid-modified vinyl ester and the amount of monomer used so that it is 30 mgKOH / g or more (more preferably 50 mgKOH / g or more) and 150 mgKOH / g or less (more preferably 120 mgKOH / g or less). .

  In the present invention, an acid-modified vinyl ester and a known radical polymerizable compound are mixed and used as a photosensitive resin composition. Such radically polymerizable compounds include radically polymerizable resins and radically polymerizable monomers. As the radical polymerizable resin, unsaturated polyester, epoxy acrylate, urethane acrylate, polyester acrylate, or the like can be used. When these radical polymerizable resins are used, in order to effectively exhibit the alkali developability improvement and the warp reduction effect derived from the acid-modified vinyl ester used as a component of the photosensitive resin composition of the present invention, resin solids ( When the total amount of the acid-modified vinyl ester and the solid content of the radical polymerizable resin is 100% by mass, the radical polymerizable resin is preferably used at 90% by mass or less. A more preferable upper limit value is 80% by mass, and a further preferable upper limit value is 70% by mass.

  As the radical polymerizable monomer, either a monofunctional (one radical polymerizable double bond) monomer or a polyfunctional monomer (two or more radical polymerizable double bonds) can be used. The radical polymerizable monomer is involved in photopolymerization, and can improve the properties of the resulting cured product and can also adjust the viscosity of the photosensitive resin composition. The preferred use amount when using the radical polymerizable monomer is 5 to 500 parts by mass (more preferably) with respect to 100 parts by mass of the resin solid content (total amount of the acid-modified vinyl ester of the present invention and the radical polymerizable resin solid content). Is 10 to 100 parts by mass).

  Specific examples of the radical polymerizable monomer include N-phenylmaleimide, N- (2-methylphenyl) maleimide, N- (4-methylphenyl) maleimide, N- (2,6-diethylphenyl) maleimide, N- ( 2-chlorophenyl) maleimide, N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-cyclohexylmaleimide, N-phenylmethylmaleimide, N- (2,4,6-tribromophenyl) Maleimide, N- [3- (triethoxysilyl) propyl] maleimide, N-octadecenylmaleimide, N-dodecenylmaleimide, N- (2-methoxyphenyl) maleimide, N- (2,4,6 -Trichlorophenyl) maleimide, N- (4-hydroxyphenyl) maleimi N-substituted maleimide group-containing monomers such as styrene, α-methylstyrene, α-chlorostyrene, vinyltoluene, p-hydroxystyrene, divinylbenzene, diallyl phthalate, diallylbenzene phosphonate, etc. Vinyl ester monomers such as vinyl acetate and vinyl adipate; (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (Meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, N-hydroxymethyl (meth) acrylamide, pentaerythritol mono (meth) acrylate, dipentaerythritol mono (Meth) acrylate, trimethylolpropane mono (meth) acrylate, 1,6-hexanediol mono (meth) acrylate, glycerol mono (meth) acrylate, (di) ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate , Trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tris [2- (meth) acryloyloxyethyl] triazine, etc. (Meth) acrylic monomers: n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, n-hexyl vinyl ether, (Hydroxy) alkyl vinyl (thio) ethers such as rohexyl vinyl ether, 2-ethylhexyl vinyl ether, 4-hydroxybutyl vinyl ether; 2- (vinyloxyethoxy) ethyl (meth) acrylate, 2- (isopropeno) Radical polymerizable double bonds such as 2- (isopropenoxyethoxyethoxyethoxy) ethyl (meth) acrylate, 2- (isopropenoxyethoxyethoxyethoxy) ethyl (meth) acrylate, etc. Vinyl (thio) ether; monomers containing acid anhydride groups such as maleic anhydride or monomers obtained by ring-opening modification of acid anhydride groups with alcohols, amines, water, etc .; N-vinylpyrrolidone, N -N-vinyl monomers such as vinyl oxazolidone; Examples thereof include compounds having one or more double bonds capable of radical polymerization, such as alcohol and triallyl cyanurate. These are appropriately selected according to the use and required characteristics of the resin composition, and can be used alone or in combination of two or more.

  From the viewpoint of workability and the like when applying the photosensitive resin composition of the present invention to a substrate, a solvent may be blended in the composition. Solvents include hydrocarbons such as toluene and xylene; cellosolves such as cellosolve and butylcellosolve; carbitols such as carbitol and butylcarbitol; cellosolve acetate, carbitol acetate, (di) propylene glycol monomethyl ether acetate, glutar Examples include esters such as acid (di) methyl, succinic acid (di) methyl, and adipic acid (di) methyl; ketones such as methyl isobutyl ketone and methyl ethyl ketone; (di) ethers such as ethylene glycol dimethyl ether, and the like. These solvents can be used alone or in combination of two or more.

  The photosensitive resin composition of the present invention can be thermally cured by using a known thermal polymerization initiator. However, for fine processing and image formation by photolithography, a photopolymerization initiator is added and photocuring is performed. It is preferable to make it.

  Known photopolymerization initiators can be used such as benzoin such as benzoin, benzoin methyl ether, benzoin ethyl ether and alkyl ethers thereof; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone. Acetophenones such as 4- (1-t-butyldioxy-1-methylethyl) acetophenone; anthraquinones such as 2-methylanthraquinone, 2-amylanthraquinone, 2-t-butylanthraquinone, 1-chloroanthraquinone; 2,4 -Thioxanthones such as dimethylthioxanthone, 2,4-diisopropylthioxanthone and 2-chlorothioxanthone; Ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal; Benzophenone, 4- (1- -Benzophenones such as butyldioxy-1-methylethyl) benzophenone and 3,3 ', 4,4'-tetrakis (t-butyldioxycarbonyl) benzophenone; 2-methyl-1- [4- (methylthio) phenyl]- Examples include 2-morpholino-propan-1-one and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1; acylphosphine oxides and xanthones.

  These photopolymerization initiators are used as one type or a mixture of two or more types, and the resin solid content (total amount of acid-modified vinyl ester and radical polymerizable resin solid content in the present invention) and radical polymerization that can be used as necessary. It is preferable that 0.5-30 mass parts is contained with respect to a total of 100 mass parts of an ionic monomer. When the amount of the photopolymerization initiator is less than 0.5 parts by mass, it is necessary to increase the light irradiation time or it is difficult for polymerization to occur even if light irradiation is performed, so that an appropriate surface hardness can be obtained. Disappear. In addition, even if it mixes photopolymerization initiator exceeding 30 mass parts, there is no merit which uses it in large quantities.

  The photosensitive resin composition of the present invention may contain a compound having a functional group capable of reacting with two or more carboxyl groups in one molecule. Thus, a stronger cured coating film can be obtained by curing using light and heat in combination. When used for image formation, heat treatment after light irradiation and alkali development can increase the degree of crosslinking while consuming carboxyl groups in the cured coating film, and can improve physical properties such as durability.

  Examples of such a compound having a functional group capable of reacting with two or more carboxyl groups in one molecule include an epoxy compound, an oxazoline compound, and an oxetane compound. Specifically, examples of the epoxy compound include novolak type epoxy resin, bisphenol type epoxy resin, alicyclic epoxy resin, triglycidyl isosialate, and the like, and examples of the oxazoline compound include 1,3-phenylenebisoxazoline. A preferable amount of use is 5 to 70 mass with respect to a total of 100 mass parts of the resin solid content (total amount of the acid-modified vinyl ester of the present invention and the radical polymerizable resin solid content) and the radical polymerizable monomer that can be used if necessary. Parts, more preferably 10 to 50 parts by mass. At this time, a curing agent such as dicyandiamide or an imidazole compound may be used in combination.

  If necessary, the photosensitive resin composition of the present invention may further include a filler such as talc, clay, barium sulfate, a coloring pigment, an antifoaming agent, a coupling agent, a leveling agent, a sensitizer, and a release agent. Well-known additives such as lubricants, plasticizers, antioxidants, ultraviolet absorbers, flame retardants, polymerization inhibitors, thickeners, and the like may be added. Furthermore, various reinforcing fibers can be used as reinforcing fibers to form a fiber-reinforced composite material.

  When the photosensitive resin composition of the present invention is used for image formation, it is applied to a substrate, exposed to obtain a cured coating film, and then an unexposed portion is formed by using a solvent such as the above-described solvent or trichloroethylene-based solvent. However, it is preferable to perform alkali development since a carboxyl group is introduced and an unexposed portion is dissolved in an alkaline aqueous solution. Specific examples of usable alkali include alkali metal compounds such as sodium carbonate, potassium carbonate, sodium hydroxide and potassium hydroxide; alkaline earth metal compounds such as calcium hydroxide; ammonia; monomethylamine, dimethylamine and trimethylamine Water-soluble organic amines such as monoethylamine, diethylamine, triethylamine, monopropylamine, dimethylpropylamine, monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, diethylenetriamine, dimethylaminoethyl methacrylate, and polyethyleneimine. 1 type (s) or 2 or more types can be used.

  The photosensitive resin composition of the present invention can be used in the form of a dry film that is applied in advance to a film of polyethylene terephthalate or the like and dried in addition to the method of applying the photosensitive resin composition directly to a substrate in a liquid state. In this case, a dry film may be laminated on a substrate, and the film may be peeled off before or after exposure.

  In addition, the CTP (Computer To Plate) system, which has been widely used in the printing plate making field, that is, the pattern forming film is not used at the time of exposure, and laser light is directly scanned and exposed on the coating film by digitized data. The drawing method can be adopted.

  The photosensitive resin composition of the present invention can achieve both alkali developability and photocurability, and furthermore, since the shrinkage of curing is small, the warpage of the substrate can be reduced during curing. Therefore, the photosensitive resin composition of the present invention is an alkali-developable photosensitive resin composition for image formation, such as a solder resist for printed wiring boards, an etching resist, an electroless plating resist, and a build-up method printed wiring board. It can be suitably used for various applications such as an insulating layer, liquid crystal display plate production, and printing plate making.

Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are not intended to limit the present invention, and all modifications made without departing from the spirit of the present invention are within the technical scope of the present invention. Is included. In the following description, “part” represents “part by mass” and “%” represents “% by mass” unless otherwise specified. Moreover, the measuring method of each physical property value in the following examples is as follows.
[Developability]
10% dipentaerythritol hexaacrylate (polyfunctional monomer) and 5% Irgacure 907 (trade name; photopolymerization initiator manufactured by Ciba Specialty Chemicals) are added to the solid content of the acid-modified vinyl ester solution. A uniform solution was applied on the copper plate so that the film thickness after drying was about 30 μm, and then heated at 90 ° C. for 30 minutes. Thereafter, the film was immersed in a 1% aqueous sodium carbonate solution at 30 ° C. for 3 minutes, and the developability (alkali solubility) was evaluated based on the remaining degree of the coating film.
[Photocurability]
The dried coating film obtained in the same manner as in the evaluation of developability was exposed to ² J / cm ² using an ultraviolet exposure device, and then immersed in a 1% aqueous sodium carbonate solution at 30 ° C. for 3 minutes. Photocurability was evaluated according to the degree of remaining.
[Warpage during curing]
10% dipentaerythritol hexaacrylate (polyfunctional monomer) and 5% Irgacure 907 (trade name; photopolymerization initiator manufactured by Ciba Specialty Chemicals) are added to the solid content of the acid-modified vinyl ester solution. The solution was applied to a polyethylene terephthalate film having a thickness of 125 μ and 60 mm × 30 mm so that the thickness after drying was about 100 μm, and then heated at 90 ° C. for 30 minutes. Next, after performing exposure at ² J / cm ² using an ultraviolet exposure device, it was further heated at 160 ° C. for 1 hour. The specimen was cooled to room temperature, and the degree of warpage was evaluated according to the following criteria.

When placed with the coated surface up (being a convex arch), the difference in height between the center and the edge is less than 5 mm (almost not warped).
Δ ---- The difference in height between the center and the edge is 5 to 10 mm (slightly warped).
× ---- The height difference between the center and the edge is 10 mm or more (remarkably warped)
Examples 1 and 2 and Comparative Examples 1 and 2
Example 1
1) Synthesis of acid-modified vinyl ester (A-1) Diglycidyl etherified product of bisphenol A propylene oxide adduct as a bifunctional epoxy compound in a vessel equipped with a stirrer, thermometer, reflux condenser, and gas introduction tube (product) Name “EP-4000”; manufactured by Asahi Denka; 324 parts of epoxy equivalent 324), 94 parts of bisphenol S as a bifunctional phenol compound, 300 parts of propylene glycol monomethyl ether acetate, 0.5 part of benzyltriethylammonium chloride as a reaction catalyst, 140 It was made to react at 10 degreeC for 10 hours, and the loss | disappearance of the phenolic hydroxyl group was confirmed. Next, 18 parts of acrylic acid, 1.3 parts of benzyltriphenylphosphonium chloride as an esterification catalyst, and 0.6 parts of methylhydroquinone as a polymerization inhibitor were charged and reacted at 120 ° C. for 20 hours. Next, as a carboxyl group introduction reaction, 121 parts of tetrahydrophthalic anhydride was charged and reacted at 100 ° C. for 10 hours. As a result, a propylene glycol monomethyl ether acetate solution containing 65% of an acid-modified vinyl ester (A-1) having an acid value of 82 mgKOH / g was obtained.
2) Evaluation of developability, photocurability, and warpage during curing of photosensitive resin composition Photosensitive resin composition using a solution of acid-modified vinyl ester (A-1). The curability and warpage during curing were evaluated.
Regarding developability, the coating film was dissolved and removed by immersion for 3 minutes. Regarding photocurability, the cured coating film after exposure was not changed even after being immersed in an aqueous sodium carbonate solution for 3 minutes. The state of warping at the time of curing was ○ (almost not warped).
Example 2
1) Synthesis of acid-modified vinyl ester (A-2) EP-4000, 259.2 parts and bisphenol A described above as a bifunctional epoxy compound in a vessel equipped with a stirrer, thermometer, reflux condenser, and gas introduction tube Type epoxy resin (trade name “YD-127”; manufactured by Tohto Kasei; epoxy equivalent 183.7), 36.7 parts, bisphenol S 94 parts, propylene glycol monomethyl ether acetate 280 parts as a bifunctional phenol compound, As a reaction catalyst, 0.4 part of benzyltriethylammonium chloride was added and reacted at 140 ° C. for 10 hours to confirm the disappearance of the phenolic hydroxyl group. Next, 18 parts of acrylic acid, 1.2 parts of benzyltriphenylphosphonium chloride as an esterification catalyst, and 0.5 parts of methylhydroquinone as a polymerization inhibitor were charged and reacted at 120 ° C. for 20 hours. Next, as a carboxyl group introduction reaction, 113 parts of tetrahydrophthalic anhydride was charged and reacted at 100 ° C. for 10 hours. As a result, a propylene glycol monomethyl ether acetate solution containing 65% of an acid-modified vinyl ester (A-2) having an acid value of 83 mgKOH / g was obtained.
2) Development of photosensitive resin composition, photocurability, evaluation of warping during curing Photosensitive resin composition using solution of acid-modified vinyl ester (A-2). The curability and warpage during curing were evaluated.
Regarding developability, the coating film was dissolved and removed by immersion for 3 minutes. Regarding photocurability, the cured coating film after exposure was not changed even after being immersed in an aqueous sodium carbonate solution for 3 minutes. The state of warping at the time of curing was ○ (almost not warped).
Comparative Example 1
1) Synthesis of comparative acid-modified vinyl ester (B-1) In a vessel equipped with a stirrer, a thermometer, a reflux condenser, and a gas introduction tube, YD-127 and 183.7 parts described above as a bifunctional epoxy compound were added. Used, 100 parts of bisphenol S as a bifunctional phenol compound, 206 parts of propylene glycol monomethyl ether acetate and 0.3 part of benzyltriethylammonium chloride as a reaction catalyst were added and reacted at 140 ° C. for 10 hours to confirm the disappearance of the phenolic hydroxyl group. . Next, 15 parts of acrylic acid, 0.9 part of benzyltriphenylphosphonium chloride as an esterification catalyst and 0.4 part of methylhydroquinone as a polymerization inhibitor were charged and reacted at 120 ° C. for 20 hours. Next, as a carboxyl group introduction reaction, 83 parts of tetrahydrophthalic anhydride was charged and reacted at 100 ° C. for 10 hours. As a result, a propylene glycol monomethyl ether acetate solution containing 65% of a comparative acid-modified vinyl ester (B-1) having an acid value of 83 mgKOH / g was obtained.
2) Development of photosensitive resin composition, photocurability, evaluation of warping during curing Photosensitive resin composition using solution of acid-modified vinyl ester (B-1) for comparison, developability by the above-described method. The photocurability and the warpage during curing were evaluated.
Regarding the developability, the coating film was not dissolved and removed even by immersion for 3 minutes. The photocurability was not evaluated because the unexposed film could not be dissolved and removed. The state of warping during curing was Δ (slightly warped).
Comparative Example 2
1) Synthesis of comparative acid-modified vinyl ester (B-2) In a container equipped with a stirrer, thermometer, reflux condenser, and gas introduction tube, a cresol novolac epoxy resin (trade name “YDCN-703”; Toto Kasei) Manufactured; epoxy equivalent 207) 207 parts, acrylic acid 73 parts, propylene glycol monomethyl ether acetate 193 parts, benzyltriphenylphosphonium chloride 0.8 part as an esterification catalyst, methylhydroquinone 0.4 part as a polymerization inhibitor, The reaction was carried out at 120 ° C. for 20 hours. Next, as a carboxyl group introduction reaction, 78 parts of tetrahydrophthalic anhydride and 0.2 part of benzyltriethylammonium chloride were added and reacted at 100 ° C. for 10 hours. As a result, a propylene glycol monomethyl ether acetate solution containing 65% of a comparative acid-modified vinyl ester (B-2) having an acid value of 84 mgKOH / g was obtained.
2) Development of photosensitive resin composition, photo-curability, evaluation of warping during curing The photosensitive resin composition using a solution of the comparative acid-modified vinyl ester (B-2), and developability by the method described above. The photocurability and the warpage during curing were evaluated.
Regarding developability, the coating film was dissolved and removed by immersion for 3 minutes. Regarding photocurability, the cured coating film after exposure was not changed even after being immersed in an aqueous sodium carbonate solution for 3 minutes. The state of warping during curing was x (remarkably warped).

Claims (3)

A photosensitive resin composition comprising an acid-modified vinyl ester having a bisphenol S skeleton and an alkylene glycol chain. The acid-modified vinyl ester according to claim 1 is a bifunctional epoxy compound, a bifunctional phenol compound, an unsaturated monomer having a functional group capable of reacting with an unsaturated monobasic acid and / or a phenolic hydroxyl group, 2. A compound synthesized from a polybasic acid anhydride and having a bisphenol S skeleton as at least a part of a bifunctional epoxy compound or a bifunctional phenol compound. The photosensitive resin composition as described in 2. The acid-modified vinyl ester according to claim 1 or 2, wherein the acid-modified vinyl ester has a functional group capable of reacting with a bifunctional epoxy compound, a bifunctional phenol compound, and an unsaturated monobasic acid and / or a phenolic hydroxyl group. The compound according to claim 1 or 2, wherein the compound is synthesized from a polybasic acid anhydride and a polybasic acid anhydride, and at least a part of the bifunctional epoxy compound has an alkylene glycol chain. The photosensitive resin composition as described.