JP2014052599A - Photosensitive resin composition and printed wiring board having cured film of photosensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition that gives a cured product having excellent characteristics in folding property (flexibility) and low warpage property without degrading various characteristics such as developing property, flame retardancy and insulating property.SOLUTION: The photosensitive resin composition comprises: an alkali-soluble resin (A) which is obtained by adding a (d) polybasic acid anhydride to a reaction product of (a) an epoxy resin having two or more epoxy groups in one molecule, (b) at least one aliphatic acid having 10 or more carbon atoms per one carboxyl group and (c) a carboxylic acid containing an ethylenically unsaturated group; and a photopolymerization initiator (B).

Description

  The present invention can provide a cured product excellent in low warpage and bendability and excellent in insulation, gold plating resistance and flame retardancy, and further in a photosensitive resin excellent in sensitivity, developability and touch dryness. The present invention relates to a composition, and a dry film and a printed wiring board using the photosensitive resin composition.

  A printed wiring board is used to form a pattern of a conductor circuit on a substrate and to mount electronic components on the soldering land of the pattern by soldering. The circuit portion excluding the soldering land is used as a permanent protective film. It is covered with a solder resist film. This prevents solder from adhering to unnecessary parts when soldering electronic components to a printed wiring board, and prevents circuit conductors from being directly exposed to air and being corroded by oxidation or humidity. To do.

  Usually, the solder resist is required to have various characteristics such as dryness to touch, sensitivity, developability, gold plating resistance, flame retardancy, and insulation. Among the printed wiring boards, flexible printed wiring boards (hereinafter sometimes referred to as “FPC”) that use a thin film substrate such as polyimide, in addition to the characteristics of the above-mentioned solder resist, are flexible so that they do not break even when bent. There is a demand for a solder resist having a low warpage with little warpage caused by shrinkage (foldability, flexibility) and shrinkage after curing.

  Furthermore, in recent years, a method of combining a halogen compound such as brominated epoxy resin with antimony trichloride or the like has been used as a method for flame retardancy. However, the use of such a halogen compound or antimony compound is not preferable from the viewpoint of environmental load, and studies have been made on flame retardancy with a compound having low environmental load.

  Examples of halogen-free flame-retardant technologies with low environmental impact include, for example, alkaline aqueous solution-soluble resins and curing agents obtained by adding polybasic acid anhydrides to the reaction products of biphenyl novolac epoxy resins and unsaturated monocarboxylic acids An aqueous alkaline solution-soluble photosensitive resin composition containing a biphenyl novolac type epoxy resin as a photopolymerization initiator and a photopolymerization initiator has been proposed (Patent Document 1). However, since the cured film of the alkaline aqueous solution-soluble photosensitive resin composition of Patent Document 1 is not sufficiently flexible, it cannot be said to be particularly suitable as a solder resist for flexible printed wiring boards.

  Moreover, since the solder resist for flexible printed wiring boards needs to have excellent flexibility in addition to halogen-free flame retardancy as described above, a carboxyl group-containing resin having a urethane structure There has been proposed a photosensitive resin composition in which a phosphoric flame retardant is combined (Patent Document 2). However, in the photosensitive resin composition of Patent Document 2, a highly flexible component via a hydrophilic urethane bond in order to impart flexibility to a resin having photosensitivity and alkali developability as a main component. Since (the component derived from the raw diisocyanate compound) is introduced into the resin, there is a problem that it is particularly difficult to maintain both heat resistance and insulating properties.

JP 2007-41107 A JP 2011-123420 A

  In view of the above circumstances, an object of the present invention is to provide a photosensitive resin composition that can form a cured product having excellent bendability and low warpage without impairing various properties such as developability, flame retardancy, and insulation. Is to provide things.

  Embodiments of the present invention include: a) an epoxy resin having two or more epoxy groups in one molecule; b) at least one fatty acid having 10 or more carbon atoms per carboxyl group; and c) ethylenic unsaturation. A photosensitive resin composition containing an alkali-soluble resin (A) obtained by adding d) a polybasic acid anhydride to a reaction product with a group-containing carboxylic acid, and a photopolymerization initiator (B). .

  One aspect of the present invention is a photosensitive resin composition in which at least one of the fatty acids is a dibasic acid. In this embodiment, the fatty acid can be used alone or in combination of two or more, but when the fatty acid is used alone, it is composed of a dibasic acid and is a mixture of two or more fatty acids. Contains at least one dibasic acid. Since fatty acids have 10 or more carbon atoms per carboxyl group, fatty acids that are dibasic acids have 20 or more carbon atoms.

  One embodiment of the present invention is a photosensitive resin composition in which at least one of the fatty acids is a linear saturated aliphatic monobasic acid having 18 or more carbon atoms.

  In one embodiment of the present invention, the polybasic acid anhydride is represented by the following general formula (1):

(In the formula, R ² represents a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, an aryl group, a carboxyl group, or a hydroxyl group, and m is an integer of 1 to 3). It is the photosensitive resin composition which is a compound represented by these.

  In one embodiment of the present invention, the epoxy resin has the following general formula (2).

(In the formula, R ¹ represents a hydrogen atom, or a linear or branched alkyl group or aryl group having 1 to 8 carbon atoms, l is an integer of 1 to 3, and n is an integer of 1 to 10. .) Is a photosensitive resin composition. In this embodiment, an epoxy resin of the general formula (2) which is a biphenyl aralkyl type epoxy resin (biphenyl novolac type epoxy resin) is used.

  One aspect of the present invention is a photosensitive resin composition further comprising a flame retardant (C) selected from the group consisting of a phosphorus element-containing compound and aluminum hydroxide.

  One embodiment of the present invention is a photosensitive resin composition further comprising a thermosetting compound (D).

  One embodiment of the present invention is a dry film obtained by applying the photosensitive resin composition to a film and then drying it.

  One embodiment of the present invention includes a cured film obtained by patterning and photocuring a coating film formed by laminating a dry film obtained by applying the photosensitive resin composition onto a film and then drying the film. It is a printed wiring board.

  One embodiment of the present invention is a printed wiring board having a cured film obtained by patterning and photocuring a coating film formed by applying the photosensitive resin composition on a substrate.

  According to the present invention, a long-chain fatty acid having a high flexibility and a structure excellent in combustion resistance and hydrophobicity, that is, a fatty acid having 10 or more carbon atoms per carboxyl group is contained in an ethylenically unsaturated group. Contains an ethylenically unsaturated group and a long-chain fatty acid skeleton with excellent flexibility, hydrophobicity, and flame resistance by adding to carboxylic acid and an epoxy resin having two or more epoxy groups in one molecule A modified epoxy resin skeleton can be formed. Furthermore, a polybasic acid anhydride is added to the hydroxyl group (mainly secondary) generated by the reaction of the carboxyl group of the long-chain fatty acid and / or ethylenically unsaturated group-containing carboxylic acid and the epoxy group of the epoxy resin to the resin. By introducing a carboxyl group, it can be solubilized in a weak alkaline aqueous solution (for example, an aqueous sodium carbonate solution, an aqueous potassium carbonate solution, etc.). Thereby, the photosensitive resin composition containing the alkali-soluble resin (A) is a resin composition having photocurability and developability in the weak alkaline aqueous solution, and the cured product has bendability and low warpage. Moreover, it is excellent in heat resistance and insulation, and it can also be set as the resin composition which has a more flame retardance by providing a flame-retardant component.

  When the fatty acid contains a dibasic acid, the resulting alkali-soluble resin (A) has a relatively different epoxy group because the different epoxy groups of the epoxy resin are bonded to each other via the dibasic acid. The rigid skeleton can be configured to be crosslinked by a covalent bond with a highly flexible skeleton derived from a long-chain fatty acid. Thereby, the coating film which hardened the photosensitive resin composition containing the alkali-soluble resin (A) of this invention can have what had heat resistance and a softness | flexibility. In addition, since the fatty acid contains a dibasic acid, an epoxy resin having a relatively low molecular weight can be adjusted to an appropriate molecular weight, so that the photosensitivity excellent in dryness to touch after drying while maintaining alkali developability. It becomes possible to make a functional resin composition.

  According to the invention, the fatty acid contains a linear saturated aliphatic monobasic acid having 18 or more carbon atoms, thereby introducing a structure derived from a long-chain fatty acid excellent in flexibility into the alkali-soluble resin. Thus, in improving the bendability of the cured coating film, a cohesive force that is considered to be derived from a hydrophobic bond of a linear saturated aliphatic chain having 18 or more carbon atoms is generated in the coating film after drying. As a result, even when a solvent is blended in the photosensitive resin composition containing the alkali-soluble resin (A) of the present invention, the coating after the preliminary drying, which is a step of volatilizing the solvent, is also dry to the touch. It can be set as the excellent photosensitive resin composition.

  According to the present invention, a phosphorus element-containing compound and / or aluminum hydroxide and a thermosetting compound can be contained without impairing various properties such as bendability and low warpage of the cured product of the photosensitive resin composition. Is possible.

  Next, the photosensitive resin composition of the present invention will be described in detail. The photosensitive resin composition of the present invention comprises: a) an epoxy resin having two or more epoxy groups in one molecule; b) at least one fatty acid having 10 or more carbon atoms per carboxyl group; and c) It contains d) an alkali-soluble resin (A) obtained by adding a polybasic acid anhydride to a reaction product with an ethylenically unsaturated group-containing carboxylic acid, and a photopolymerization initiator (B). And Each of the above components is as follows.

Alkali-soluble resin (A)
The alkali-soluble resin (A) includes: a) an epoxy group of an epoxy resin having two or more epoxy groups in one molecule; b) at least one fatty acid having 10 or more carbon atoms per carboxyl group; c) By reacting an ethylenically unsaturated group-containing carboxylic acid, a reaction product, a long-chain fatty acid-modified ethylenically unsaturated group-containing modified epoxy resin is obtained, and further, a long-chain fatty acid and / or an ethylenically unsaturated group is contained. D) A polybasic acid anhydride is added to a hydroxyl group (mainly secondary) generated by a reaction between a carboxyl group of a carboxylic acid and an epoxy group of an epoxy resin to introduce a free carboxyl group into the resin.

a) Epoxy resin having two or more epoxy groups in one molecule Any epoxy resin having two or more epoxy groups in one molecule can be used as long as it is a bifunctional or more epoxy resin. The epoxy equivalent of an epoxy resin having two or more epoxy groups in one molecule is not particularly limited, but prevents deterioration in photosensitivity and bendability due to a decrease in the ratio of introduction of ethylenically unsaturated group-containing carboxylic acid and long chain fatty acid. From the point which does, 1000 or less are preferable and 100-500 are especially preferable.

  Examples of the epoxy resin having two or more epoxy groups in one molecule include biphenyl aralkyl type epoxy resin, phenyl aralkyl type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, and silicone-modified. Rubber modified epoxy resin such as epoxy resin, ε-caprolactone modified epoxy resin, phenol novolac type epoxy resin such as bisphenol A type, bisphenol F type, bisphenol AD type, cresol novolac type epoxy resin such as о-cresol novolac type, cyclic fat Polyfunctional epoxy resin, glycidyl ester type polyfunctional epoxy resin, glycidylamine type polyfunctional epoxy resin, heterocyclic polyfunctional epoxy resin, bisphenol-modified novolac type epoxy resin, polyfunctional modified type Examples thereof include a borac type epoxy resin, a condensate type epoxy resin of a phenol and an aromatic aldehyde having a phenolic hydroxyl group, an epoxy resin containing a fluorene skeleton, and an epoxy resin into which an adamantane skeleton is introduced. Moreover, what introduce | transduced halogen atoms, such as Br and Cl, to these resin can also be used.

  Among these, biphenyl aralkyl type epoxy resin and dicyclopentadiene type epoxy resin are preferable from the viewpoint of the photosensitivity of the cured product of the photosensitive resin composition, bendability, low warpage, heat resistance and insulation, and bendability. In terms of heat resistance and flame retardancy, the following general formula (2)

(In the formula, R ¹ represents a hydrogen atom, or a linear or branched alkyl group or aryl group having 1 to 8 carbon atoms, l is an integer of 1 to 3, and n is an integer of 1 to 10. .) Is particularly preferred.

Examples of commercially available epoxy resins having two or more epoxy groups in one molecule include NC-3000 (manufactured by Nippon Kayaku Co., Ltd., R ^{1 in the} general formula (2) is a hydrogen atom. Biphenyl aralkyl type epoxy resin). The above-mentioned epoxy resin having two or more epoxy groups in one molecule may be used alone or in combination of two or more.

b) Fatty acid having 10 or more carbon atoms per carboxyl group Fatty acid having 10 or more carbon atoms per carboxyl group is added to the epoxy group of an epoxy resin having two or more epoxy groups in one molecule. By reacting and introducing the long-chain hydrocarbon structure derived from the fatty acid into the resin, the flexibility and water resistance of the cured product of the photosensitive resin composition can be improved. The fatty acid having 10 or more carbon atoms per carboxyl group is not particularly limited, and either saturated or unsaturated can be used, and either linear or branched can be used. Examples of the fatty acid include a monobasic acid having 10 or more carbon atoms and a dibasic acid having 20 or more carbon atoms, and the monobasic acid and dibasic acid from the viewpoint of compatibility between bendability and dryness to touch. Is preferably linear or branched having 2 or less side chains having 2 or less carbon atoms.

  In addition, while introducing the fatty acid structure into the epoxy resin, different epoxy groups of the epoxy resin are bonded to each other via the fatty acid, so that the relatively rigid skeleton of the epoxy resin is flexible from the long chain fatty acid. The fatty acid is at least from the point of being able to have a structure crosslinked by a covalent bond with a high long-chain hydrocarbon skeleton, and imparting a structure excellent in bending property, heat resistance and chemical resistance of the cured coating film to the epoxy resin. It preferably contains one dibasic acid. Furthermore, in the present invention, it is possible to improve the bendability of the cured coating film by introducing many flexible long-chain hydrocarbon skeletons derived from long-chain fatty acids. In addition to a dibasic acid having a number of 10 or more, a fatty acid, a polyfunctional epoxy resin, and an ethylenically unsaturated group-containing carboxylic acid can be obtained by using a single base having 10 or more carbon atoms per carboxyl group. The molecular weight of the reaction product can be appropriately controlled while improving the composition ratio of the component derived from the long-chain fatty acid. In this way, by adjusting the molecular weight appropriately, it is possible to achieve both dryness of the coated film after drying, solubility in weak alkaline developer (ie, alkali developability) and flexibility of the cured film. It becomes. As the monobasic acid, in particular, a linear saturated monobasic acid having 18 or more carbon atoms per carboxyl group is included, so that the aggregation is considered to be derived from the hydrophobic bond of the linear saturated aliphatic chain. Force is generated in the coating after drying, and the coating after pre-drying not only has excellent touch drying properties, but also contains many structures derived from long-chain fatty acids with excellent flexibility. The coating film can have excellent bendability and low warpage.

  The number of carbon atoms per carboxyl group is preferably 10 or more from the viewpoint of obtaining flexibility and hydrophobicity in the cured coating film. On the other hand, the upper limit of the number of carbon atoms per carboxyl group is not particularly limited, but is preferably 22 or less from the viewpoint of maintaining alkali developability.

  Specific examples of fatty acids having 10 or more carbon atoms per carboxyl group include monobasic acids such as capric acid (decanoic acid: C10), tetradecanoic acid (C11), lauric acid (dodecanoic acid: C12), Pentadecanoic acid (C13), myristic acid (tetradecanoic acid: C14), pentadecylic acid (C15), palmitic acid (hexadecanoic acid: C16), margaric acid (heptadecanoic acid: C17), stearic acid (C18), isostearic acid (C18) Tuberculostearic acid (C19), arachidic acid (C20), behenic acid (C22), lignoceric acid (C23), tetracosanoic acid (C24), hexacosanoic acid (C26), octacosanoic acid (C28), triacontanoic acid (C30) ) And the like.

  Dibasic acids include eicosane diacid (C20), ethyl octadecanedioic acid (C20), eicosadiene diacid (C20), vinyl octadecaenedioic acid (C20), dimethyl eicosadiene diacid (C22), dimethyleico C36 dimer acid by dimerization reaction of unsaturated fatty acids such as sundioic acid (C22), diphenylhexadecanedioic acid (C28), oleic acid (C18), etc., and hydrogenated olefinic double bond of the dimer acid Examples thereof include hydrogenated dimer acid. As a commercial item of the above-mentioned dibasic acid, for example, “SL-20” manufactured by Okamura Seiyaku Co., Ltd., whose main component is eicosane diacid represented by the following formula (3),

  “SB-20” manufactured by Okamura Seiyaku Co., Ltd., whose main component is 8-ethyloctadecanedioic acid represented by the following formula (4),

  Mainly (8E, 12E) -eicosa-8,12-dienedioic acid represented by the following formula (5) and (8E) -11-vinyloctadeca-8-enedioic acid represented by the following formula (6), respectively. "ULB-20" manufactured by Okamura Essential Oil Co., Ltd.

  “IPU-22” manufactured by Okamura Seiyaku Co., Ltd., whose main component is (8E, 12E) -9,12-dimethyl-eicosa-8,12-dienedioic acid, represented by the following formula (7):

  “IPS-22” manufactured by Okamura Seiyaku Co., Ltd., which is mainly composed of 9,12-dimethyleicosanedioic acid represented by the following formula (8),

  “ST-2P” manufactured by Okamura Seiyaku Co., Ltd., whose main component is 8,9-diphenylhexadecanedioic acid represented by the following formula (9),

  "UNIDYM10", "UNIDYM14", "UNIDYM18", "UNIDYM22", "UNIDYM35" made by Arizona Chemical, whose main component is C36 dimer acid having an olefinically unsaturated double bond, olefinic unsaturation of the C36 dimer acid Examples thereof include “Pripol 1010” manufactured by Croda, which is a hydrogenated dimer acid in which a double bond is hydrogenated.

  The above fatty acids having 10 or more carbon atoms per carboxyl group may be used alone or in combination of two or more.

  The reaction method of an epoxy resin having two or more epoxy groups in one molecule and at least one fatty acid having 10 or more carbon atoms per carboxyl group may be a known method, for example, the above epoxy resin And a reaction method in which the fatty acid is heated in a suitable diluent.

  The ratio of the fatty acid having 10 or more carbon atoms per carboxyl group in the alkali-soluble resin (A) (preparation ratio) is not particularly limited, but is 15% by mass from the viewpoint of further improving bendability and low warpage. The above is preferable, and 22% by mass or more is particularly preferable from the viewpoint of surely improving the bendability. On the other hand, the upper limit is preferably 50% by mass from the viewpoint of maintaining photosensitivity by appropriately maintaining the introduction amount of the ethylenically unsaturated group-containing carboxylic acid.

c) Ethylenically unsaturated group-containing carboxylic acid Ethylenically unsaturated group-containing carboxylic acid reacts with an epoxy group of an epoxy resin having two or more epoxy groups in one molecule, and the epoxy resin is reacted with a photopolymerization initiator. A photocurable group is introduced that can be polymerized by the generated free radicals. The ethylenically unsaturated group-containing carboxylic acid is not particularly limited as long as it imparts photocurability to the epoxy resin. For example, acrylic acid, methacrylic acid, β-acryloxypropionic acid, ω-carboxypolycaprolactone- Examples thereof include carboxylic acids capable of introducing an acryloyl group or a methacryloyl group into an epoxy resin, such as (meth) acrylic acid, crotonic acid, and cinnamic acid. Among these, acrylic acid and methacrylic acid (hereinafter sometimes referred to as (meth) acrylic acid) are preferable, and acrylic acid is particularly preferable. These may be used alone or in combination of two or more. The reaction method of the epoxy resin having two or more epoxy groups in one molecule and the ethylenically unsaturated group-containing carboxylic acid is not particularly limited. For example, the epoxy resin and the ethylenically unsaturated group-containing carboxylic acid are appropriately used. A reaction method of heating in a diluent is mentioned.

d) Polybasic acid anhydride Polybasic acid anhydrides are a hydroxyl group and an ethylenically unsaturated group produced by the reaction of the epoxy resin with at least one fatty acid having 10 or more carbon atoms per carboxyl group. A free carboxyl group is introduced into the epoxy resin in response to a hydroxyl group generated by the reaction with the contained carboxylic acid. The polybasic acid anhydride to be used is not particularly limited, and either saturated or unsaturated can be used. Polybasic acids include, for example, succinic acid, maleic acid, adipic acid, citric acid, phthalic acid, tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, 3-ethyltetrahydrophthalic acid, 4- Ethyltetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, 3-ethylhexahydrophthalic acid, 4-ethylhexahydrophthalic acid, methyltetrahydrophthalic acid, methylhexahydro Examples include anhydrides of polybasic acids such as phthalic acid, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, trimellitic acid, pyromellitic acid and diglycolic acid.

  As the polybasic acid anhydride, from the viewpoint of alkali developability, the following general formula (1)

(In the formula, R ² represents a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, an aryl group, a carboxyl group, or a hydroxyl group, and m is an integer of 1 to 3). The compound represented by these is preferable. Since the compound represented by the general formula (1) has a free carboxyl group and an acid anhydride group in one molecule, it is produced by a reaction between a carboxylic acid having a fatty acid and / or an ethylenically unsaturated group and an epoxy group. The hydroxyl group thus formed reacts with the acid anhydride group of the above compound and is introduced into the resin skeleton by an ester bond. At this time, two carboxyl groups can be introduced into the resin per molecule of the compound represented by the general formula (1). Therefore, while introducing many long-chain fatty acid components into the resin, it is possible to introduce into the resin an amount of carboxyl groups necessary to efficiently obtain alkali solubility with a small number of hydroxyl groups. Thereby, the high softness | flexibility and hydrophobicity of the cured coating film by introduction | transduction of a long-chain fatty-acid component, and the alkali developability after preliminary drying can be made compatible at a high level. In particular, the alkali-soluble resin of the present invention in which the compound represented by the general formula (1) is introduced while designing the same amount of carboxylic acid is the present invention in which an acid anhydride other than the compound represented by the general formula (1) is introduced. Compared to the alkali-soluble resin, alkali development can be performed in a shorter time. In addition, these compounds may be used independently and may mix and use 2 or more types in order to adjust alkali developability moderately.

  The solid content acid value of the alkali-soluble resin (A) is preferably 50 mgKOH / g to 200 mgKOH / g from the viewpoint of alkali development. If it is less than 50 mgKOH / g, alkali development at a sufficient speed tends to be difficult, and if it exceeds 200 mgKOH / g, it tends to be difficult to maintain the exposure pattern due to swelling of the exposed part by an alkali developer. Further, the upper limit is more preferably 150 mgKOH / g from the viewpoints of preventing moisture resistance and insulation from being lowered and maintaining gold plating resistance.

  Moreover, the weight average molecular weight of alkali-soluble resin (A) has the preferable range of 3000-50000. If it is less than 3000, the toughness and the touch drying property of the cured product tend to be lowered, and if it exceeds 50000, the alkali developability may be significantly lowered. The double bond equivalent (hereinafter referred to as “double bond equivalent”) derived from the ethylenically unsaturated group-containing carboxylic acid of the alkali-soluble resin (A) is not particularly limited, but is preferably 500 to 5000 g / eq. If it is less than 500, the crosslink density by photocuring tends to increase and the warpability tends to deteriorate due to the bendability and curing shrinkage of the cured coating film. If it exceeds 5000, the photocurability becomes low and the required exposure due to the decrease in sensitivity. There is a tendency to increase the amount, and to decrease the chemical resistance and plating resistance of the cured coating film. More preferably, it is 700-3500 from the point which makes the bendability and photosensitivity of a cured coating film compatible. In addition, as the alkali-soluble resin, other known resins having a carboxyl group can be used in combination with the alkali-soluble resin (A) of the present invention. For example, an acid anhydride compound is added to the hydroxyl group of epoxy (meth) acrylate. Urethane-modified epoxy acrylate synthesized by condensation of added resin, epoxy (meth) acrylate, diisocyanate, and dialcohols having carboxyl groups such as dimethylolpropionic acid and dimethylolbutanoic acid, (meth) acrylic acid and styrene And a copolymer of an ethylenically unsaturated group-containing compound such as monofunctional (meth) acrylates, and a resin obtained by adding a compound having an ethylenically unsaturated group and an epoxy group thereto.

Photopolymerization initiator (B)
The photopolymerization initiator is not particularly limited as long as it is generally used. For example, oxime ester photopolymerization initiator, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether Benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ) , Benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiarybutylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2- Ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4 diethylthioxanthone, benzyldimethyl ketal, acetophenone dimethyl ketal, P-dimethylaminobenzoic acid ethyl ester, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, Bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl- Nthylphosphine oxide, (2,4,6-trimethylbenzoyl) ethoxyphenylphosphine oxide, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], 2- Propanedione-2-O-benzoyloxime, 1-phenyl-1,2-propanedione-2-O-benzoyloxime, ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole- 3-yl]-, 1- (O-acetyloxime) and the like. These may be used alone or in combination of two or more.

  When the photosensitive resin composition of the present invention is irradiated with ultraviolet light having a wavelength of 300 to 450 nm, free radicals are generated from the photopolymerization initiator, and the ethylenically unsaturated group of the alkali-soluble resin used in the present invention The photosensitive resin composition can be cured by initiating radical polymerization. Although the compounding quantity of a photoinitiator is not specifically limited, 2-20 mass parts is preferable with respect to 100 mass parts of alkali-soluble resin, and 5-15 mass parts is especially preferable.

  In the photosensitive resin composition of this invention, a flame retardant (C) and a thermosetting compound (D) can further be mix | blended as needed other than said each component.

Flame retardant (C)
By mix | blending a flame retardant with the photosensitive resin composition of this invention, the flame retardance of hardened | cured material can be improved more. Although a flame retardant is not specifically limited, A well-known thing can be used, For example, a phosphorus element containing compound, aluminum hydroxide, etc. can be mentioned. Specific examples of the phosphorus element-containing compound include tris (chloroethyl) phosphate, tris (2,3-dichloropropyl) phosphate, tris (2-chloropropyl) phosphate, tris (2,3-bromopropyl) phosphate, tris (bromo). Halogenated phosphoric acid such as chloropropyl) phosphate, 2,3-dibromopropyl-2,3-chloropropyl phosphate, tris (tribromophenyl) phosphate, tris (dibromophenyl) phosphate, tris (tribromoneopentyl) phosphate Non-halogen aliphatic phosphates such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, triallyl phosphine; Riphenyl phosphate, cresyl diphenyl phosphate, dicresyl phenyl phosphate, tricresyl phosphate, trixylenyl phosphate, xylenyl diphenyl phosphate, tris (isopropylphenyl) phosphate, isopropylphenyl diphenyl phosphate, diisopropylphenylphenyl phosphate, tris (trimethyl Phenyl) phosphate, tris (t-butylphenyl) phosphate, hydroxyphenyl diphenyl phosphate, octyl diphenyl phosphate, 3-glycidyloxypropylene diphenylphosphine oxide, 3-glycidyloxydiphenylphosphine oxide, diphenylvinylphosphine oxide, 2- (9,10 -Dihydro-9-oxa-10-oxai -10-phosphaphenanthrene-10-yl) methylsuccinic acid bis- (2-hydroxyethyl) -ester non-halogen aromatic phosphate such as polymer; aluminum trisdiethylphosphinate, aluminum diethylphosphinate, trismethylethylphosphine Aluminum phosphate, aluminum trisdiphenylphosphinate, zinc bisdiethylphosphinate, zinc bismethylethylphosphinate, zinc bisdiphenylphosphinate, titanyl bisdiethylphosphinate, titanium tetrakisdiethylphosphinate, titanyl bismethylethylphosphinate, tetrakismethylethyl Metal salts of phosphinic acid such as titanium phosphinate, titanyl bisdiphenylphosphinate, titanium tetrakisdiphenylphosphinate, etc. The Among these, a solid flame retardant aluminum trisdiethylphosphinate, aluminum diethylphosphinate, and aluminum hydroxide are preferable from the viewpoint of excellent flame retardancy and dryness to touch. In particular, aluminum trisdiethylphosphinate is preferable because it exhibits excellent flame retardancy. Aluminum trisdiethylphosphinate is commercially available, for example, as “Exorit OP-935” manufactured by Clariant Japan Co., Ltd. and “Exorit OP-930” manufactured by the same company. These may be used alone or in combination of two or more.

  Although the compounding quantity of a flame retardant is not specifically limited, 50 mass parts is preferable from the point which prevents the fall of a bendability reliably with respect to 100 mass parts of alkali-soluble resin, and 40 mass parts is especially preferable.

Thermosetting compound (D)
The thermosetting compound is activated by applying heat to increase the crosslink density of the cured product and impart sufficient mechanical strength and heat resistance to the cured product. Examples of the thermosetting compound include polyfunctional epoxy compounds such as the above epoxy resins used for the synthesis of the alkali-soluble resin (A), block isocyanate compounds, maleimide compounds, benzoxazine compounds, dicyandiamide (DICY), and derivatives thereof. And latent curing agents such as melamine and its derivatives. The blocked isocyanate can be used even if it is commercially available, for example, MF-K60B, SBN-70D, TPA-B80E, 17B-60PX, E402-B80T (above, manufactured by Asahi Kasei Chemicals Co., Ltd., trade name), Sumidur BL-3175, BL-4165, BL-1100, BL-1265, Death Module TPLS-2957, TPLS-2062, TPLS-2078, TPLS-2117, Desmotherm 2170, Desmotherm 2265 (above, manufactured by Sumitomo Bayer Urethane Co., Ltd., trade name) ), Coronate 2512, Coronate 2513, Coronate 2520 (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name), B-830, B-815, B-846, B-870, B-874, B-882 (Mitsui Takeda Chemical Co., Ltd.) , Product name), BI7986, BI 7951, BI7982, BI7960 (Baxenden, trade name), Karenz MOI-BM, Karenz MOI-BP (Showa Denko, trade name) and the like. These blocked isocyanates may be used alone or in combination of two or more.

  Although the compounding quantity of a thermosetting compound is not specifically limited, From the point of the balance of the mechanical strength of hardened | cured material and developability, 10-50 mass parts is preferable with respect to 100 mass parts of alkali-soluble resin, and 20-30. Part by mass is particularly preferred.

  Moreover, the photosensitive resin composition of this invention is a photocurable compound, a filler, an inorganic ion exchanger, a coloring agent, an antifoamer, a solvent other than said (A)-(D) component as needed. Etc. can be contained.

  The photocurable compound is a photosensitive compound that assists photocuring of the photosensitive resin composition during exposure by photocuring by irradiation with ultraviolet rays. Examples of the photocurable compound include compounds having an ethylenically unsaturated group, such as polyether (meth) acrylate, polyester (meth) acrylate, urethane (meth) acrylate, polycarbonate polyol (meth) acrylate, An epoxy (meth) acrylate etc. are mentioned. Specific examples thereof include pentaerythritol, dipentaerythritol, trimethylolpropane, butanediol, hexanediol, dicyclopentadienedimethanol, stearyl alcohol, behenyl alcohol, phenol, bisphenol A and the like, and ethylene oxide modification, propylene oxide modification. Epoxy (meth) acrylate, hydroxyalkyl (meth) acrylate and various polyols acrylated with (meth) acrylate, bisphenol A type epoxy resin, phenol novolac type epoxy resin, cresol novolak type epoxy resin, etc. Urethane acrylates and polycarbonate diols, which are condensed with various diisocyanates and triisocyanates (Meth) acrylated polycarbonate diol (meth) acrylates, phenoxyethyl methacrylate, diethylene glycol dimethacrylate, 2-hydroxyethyl methacrylate, 2-hydroxy-3-phenoxypropyl acrylate, ditrimethylolpropane tetraacrylate, 2-methacrylic acid 2- Hydroxyethyl, phenoxyethyl methacrylate, diethylene glycol monomethacrylate, 2-hydroxy-3-phenoxypropyl acrylate, phenol EO modified (meth) acrylate, nonylphenol PO modified (meth) acrylate, isobornyl (meth) acrylate, octyl (meth) Acrylate, dipropylene glycol di (meth) acrylate, ethoxylated O-phenylphenol (meth) Acrylate, phenoxypolyethylene glycol (meth) acrylate, 2-hydroxy-3-acryloyloxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, benzyl (Meth) acrylate, phenoxyethyl (meth) acrylate, N-acryloyloxyethyl hexahydrophthalimide, monohydroxyethyl (meth) acrylate phthalate, tricyclodecane dimethylol di (meth) acrylate, bisphenol F EO modified di (meta) ) Acrylate, 9,9-bis [4- (2-acryloyloxyethoxy) phenyl] fluorene, isocyanuric acid-modified di (meth) acrylate, trimethylolpropane tri (me Acrylate), triethylene glycol di (meth) acrylate, neopentyl di (meth) acrylate, isocyanuric acid modified tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dimethylolpropane tetra (meth) acrylate, dipentaerythritol penta ( And (meth) acrylate and dipentaerythritol hexa (meth) acrylate. The compounding quantity of a photocurable compound can be selected suitably, and 5-100 mass parts is preferable with respect to 100 mass parts of alkali-soluble resin. When the amount is less than 5 parts by mass, the photosensitivity tends to decrease. When the amount is more than 100 parts by mass, the alkali developability tends to decrease. More preferably, it is 10-80 mass parts with respect to 100 mass parts of alkali-soluble resin.

  Among the fillers, the inorganic filler is a filler mainly for improving the mechanical strength and heat resistance of the cured coating film. The filler is not particularly limited as long as it is generally used, and examples of the inorganic filler include barium sulfate, crystalline silica, amorphous silica, talc, alumina, mica, magnesium oxide, boron nitride and the like. be able to. The organic filler is added to improve heat resistance and flexibility. The organic filler has a structure in which a resin such as urethane, acrylic, or silicone is previously cross-linked, has a single composition, or has a multi-layer structure such as a core-shell type in which the components differ between the core and the shell. You can choose the right one. The organic filler is particularly preferably a urethane type or a silicone type which is excellent in flexibility from the viewpoint of bendability and chemical resistance. Among the above organic fillers, for example, as commercially available urethane resins, specifically, “RHC-730” manufactured by Dainichi Seika Co., Ltd., “Art Pearl C” manufactured by Negami Kogyo Co., Ltd. -300 "," C-400 "," C-800 "," P-800T "," U-600T "," CF-600T "," JB-400T "," JB- " Examples include powdered urethane resins such as “800T”, “CE-400T”, “CE-800T”, “MM-120TW”, “C-400R”, and “JB-8000”. The blending amount of the filler can be selected as appropriate, but is preferably 300 or less from the viewpoint of preventing the tendency for alkali developability, photosensitivity, and bendability to decrease with respect to 100 parts by mass of the alkali-soluble resin.

  The inorganic ion exchanger is a so-called ion catcher, which takes in ions of opposite charge and performs ion exchange, thereby removing ionic impurities such as chlorine ions and sodium ions remaining in the photosensitive resin composition of the present invention. Capture and fix. Furthermore, to prevent the ion migration phenomenon in the cured product of the photosensitive resin composition even under high-temperature and high-humidity conditions by capturing and fixing metal ions and halogen ions that move as ions by applying voltage. Used for. By preventing this ion migration phenomenon, when the photosensitive resin composition of the present invention is used for a solder resist film of a printed wiring board, a short circuit between electrodes caused by the solder resist film can be surely prevented.

  Inorganic ion exchangers include, for example, “IXE-100” and “IXE-300” manufactured by Toagosei Co., Ltd. as cation exchangers, and “Toyo Gosei Co., Ltd.” manufactured by Toagosei Co., Ltd. “IXE-500”, “IXE-530”, “IXE-550”, “IXE-700”, “IXE-700F”, “IXE-800”, both ion exchangers, manufactured by Toagosei Co., Ltd. IXE-600 "," IXE-633 "," IXE-6107 "," IXE-6136 "," IXEPLUS-A1 "," IXEPLUS-A2 "," IXEPLUS-B1 ", and the like. Among these, “IXE-100”, which is a cation exchanger, is particularly desirable because of its excellent insulation, chemical resistance, and heat resistance. These may be used alone or in combination of two or more.

  Although the compounding quantity of an inorganic ion exchanger is not specifically limited, 1-30 mass parts is preferable with respect to 100 mass parts of alkali-soluble resin. When the amount is less than 1 part by mass, the insulating property tends to be insufficiently improved. When the amount is more than 30 parts by mass, the bending performance tends to be lowered. More preferably, it is 3-15 mass parts.

  Examples of the colorant include a white colorant, a black colorant, a blue colorant, and a yellow colorant. Specific examples of these colorants include metal oxide inorganic pigments such as titanium oxide, organic pigments such as phthalocyanines, perylenes and anthraquinones, and carbons such as acetylene black. A well-known thing can be used for an antifoamer, for example, a silicone type, a hydrocarbon type, an acryl type, a vinyl ether type etc. can be mentioned.

  A solvent is used in order to adjust the viscosity and drying property of the photosensitive resin composition. Examples of the solvent include ketones such as methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene and xylene, alcohols such as methanol, isopropanol and cyclohexanol, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, Petroleum solvents such as petroleum ether and petroleum naphtha, cellosolves such as cellosolve and butylcellosolve, carbitols such as carbitol and butylcarbitol, ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, diethylene glycol mono Examples thereof include acetates such as ethyl ether acetate and butyl carbitol acetate. The amount of the solvent used is preferably 1 to 500 parts by weight with respect to 100 parts by weight of the alkali-soluble resin.

  The method for producing the photosensitive resin composition of the present invention described above is not limited to a specific method. For example, after blending the above components at a predetermined ratio, at room temperature, kneading means such as a three roll, ball mill, sand mill, etc. Alternatively, it can be produced by kneading or mixing by a stirring means such as a super mixer or a planetary mixer. Further, prior to the kneading or mixing, if necessary, preliminary kneading or premixing may be performed.

  Next, an example of how to use the above-described photosensitive resin composition of the present invention will be described. First, a method for forming a solder resist film by applying the photosensitive resin composition of the present invention on a flexible wiring board substrate having a circuit pattern formed by etching a copper foil will be described as an example.

  On the flexible wiring board substrate having a circuit pattern formed by etching a copper foil, the photosensitive resin composition produced as described above is formed in a desired thickness using a known method such as a screen printing method or a spray coating method. Apply it. After coating, if necessary, preliminary drying is performed by heating at a temperature of about 60 to 80 ° C. for about 15 to 60 minutes to volatilize the solvent in the photosensitive resin composition, and the solvent is volatilized from the photosensitive resin composition. To make the surface of the coating film tack-free. On the coated photosensitive resin composition, a negative film having a light-transmitting pattern other than the land of the circuit pattern is brought into close contact, and ultraviolet rays (for example, in a wavelength range of 300 to 400 nm) are irradiated from above. Then, the coating film is developed by removing the non-exposed areas corresponding to the lands with a dilute alkaline aqueous solution. As a developing method, a spray method, a shower method, or the like is used, and examples of the diluted alkaline aqueous solution used include 0.5 to 5% sodium carbonate aqueous solution. Next, the target solder resist film can be formed on the substrate for a flexible wiring board by curing for 20 to 80 minutes with a hot-air circulating dryer or the like at 130 to 170 ° C.

  Next, a method for forming a solder resist film using a dry film coated with the photosensitive resin composition of the present invention on a flexible wiring board substrate having a circuit pattern formed by etching a copper foil will be described. To do.

  The dry film includes a support film (for example, a thermoplastic film such as a polyethylene terephthalate film and a polyester film), a solder resist layer coated on the support film, and a cover film (for example, a polyethylene film) that protects the solder resist layer. , Polypropylene film). After coating the photosensitive resin composition on the support film by a known method such as a roller coating method, the coating film is dried to form a solder resist layer on the support film, and then on the formed solder resist layer A dry film can be created by laminating a cover film on the substrate. A solder resist film is formed on the flexible wiring board substrate by bonding the solder resist layer and the flexible wiring board substrate while peeling the cover film of the dry film. Thereafter, in the same manner as described above, a solder resist film having a target circuit pattern can be formed on the flexible wiring board substrate by performing the steps of exposure, development, and curing.

  An electronic circuit unit is formed by soldering an electronic component to the flexible wiring board substrate coated with the cured film thus obtained by a jet soldering method, a reflow soldering method, or the like. .

  Next, examples of the present invention will be described. However, the present invention is not limited to these examples as long as the gist thereof is not exceeded.

About alkali-soluble resin (A) Physical property measurement conditions The solid content was obtained by drying the alkali-soluble resin (A) at 150 ° C. for 2 hours and calculating the mass ratio before and after drying. The solid content acid value was calculated by first measuring the acid value of the alkali-soluble resin (A) by the phenolphthalein color change method based on alkali neutralization titration, and then multiplying by the solid content ratio. The double bond equivalent was calculated by the solid content mass (g) of the alkali-soluble resin (A) / the number of moles of ethylenically unsaturated group-containing carboxylic acid.
2. The weight average molecular weight was measured as follows.
It measured using the Tosoh GPC apparatus. The measurement conditions are as follows.
Column: TSK gel (manufactured by Tosoh Corporation, "SuperH4000", "SuperHZ2500")
Detector: Differential refraction Solvent: Tetrahydrofuran Solute concentration: 10mg / mL
Standard material: Standard polystyrene (manufactured by VARIAN, "EASICAL PS-2" (monodisperse sample))
Flow rate: 0.3mL / min
Temperature: 40 ° C

  Synthesis examples of the alkali-soluble resins A-1) to A-16) will be described with reference to Table 1.

Synthesis example A-1)
In a 300 mL separable flask equipped with a stirrer and a reflux condenser, diethylene glycol monoethyl ether acetate (hereinafter referred to as “EDGAC”) 84.1 g, distilled dimer acid (C36) (manufactured by Arizona Chemical, UNIDYM14) 33.2 g, acrylic acid 14.4 g Then, 0.53 g of triphenylphosphine and 0.27 g of methoxyhydroquinone were charged, and the mixture was heated and stirred until it was dissolved at 80 ° C. while blowing 0.1 mL / sec of nitrogen / air (2: 1) into the reaction vessel. Separately, 89.2 g (111.5 g as a solution) of biphenyl aralkyl type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent 227) dissolved in 80% by mass in a 1: 1 mixture of EDGAC and Solvesso 150 After warming to 80 ° C., the mixture was put into the flask and heated and stirred at 115 ° C. for about 10 hours to react until the acid value of the reaction solution became 5 mgKOH / g or less. 22.8 g of hydrogenated trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Company, Inc., HTMAn-s) was further added to the reaction product, and the mixture was heated and stirred at 100 ° C. for 4 hours in the atmosphere. The disappearance of the acid anhydride group was confirmed by FT-IR (infrared spectrophotometer). As a result, an alkali-soluble resin A-1 having a solid content of 60% by mass, a solid content acid value of 85 mgKOH / g, and a weight average molecular weight of 6000 was obtained.

Synthesis example A-2)
In a 300 mL separable flask equipped with a stirrer and a reflux condenser, EDGAC 84.5 g, Distilled dimer acid (C36) (Arizona Chemical, UNIDYM14) 32.6 g, Methacrylic acid 16.8 g, Triphenylphosphine 0.53 g, Methoxyhydroquinone 0.27 g The mixture was heated and stirred until dissolved at 80 ° C. while blowing 0.1 mL / sec of nitrogen / air (2: 1) into the reaction vessel. Separately, 87.5 g (109.3 g as a solution) of biphenylaralkyl type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent 227) dissolved at 80% by mass in a 1: 1 mixture of EDGAC and Solvesso 150 After warming to 0 ° C., the mixture was put into the flask and heated and stirred at 115 ° C. for about 10 hours to react until the acid value of the reaction solution became 5 mgKOH / g or less. 22.8 g of hydrogenated trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd., HTMAn-s) was further added to the reaction product, and the mixture was heated and stirred at 100 ° C. for 4 hours in the atmosphere. The disappearance of the acid anhydride group was confirmed by FT-IR (infrared spectrophotometer). As a result, an alkali-soluble resin A-2 having a solid content of 60% by mass, a solid content acid value of 85 mgKOH / g, and a weight average molecular weight of 8400 was obtained.

Synthesis example A-3)
In a 300 mL separable flask equipped with a stirrer and a reflux condenser, 84.0 g of EDGAC, 16.3 g of dimer dimer acid (C36) (UNIDYM14, manufactured by Arizona Chemical), 16.3 g of stearic acid, 14.7 g of acrylic acid, 0.53 g of triphenylphosphine Then, 0.27 g of methoxyhydroquinone was charged, and the mixture was heated and stirred until it was dissolved at 80 ° C. while blowing nitrogen and air (2: 1) into the reaction vessel at 0.1 mL / sec. Separately, 89.7 g of phenyl aralkyl type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent 227) dissolved in a 1: 1 mixture of EDGAC and Solvesso 150 at 80% by mass (112.1 g as a solution) is 80. After warming to 0 ° C., the mixture was put into the flask and heated and stirred at 115 ° C. for about 10 hours to react until the acid value of the reaction solution became 5 mgKOH / g or less. 22.7 g of hydrogenated trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd., HTMAn-s) was further added to the reaction product, and the mixture was heated and stirred at 100 ° C. for 4 hours in the atmosphere. The disappearance of the acid anhydride group was confirmed by FT-IR (infrared spectrophotometer). As a result, an alkali-soluble resin A-3 having a solid content of 60% by mass, a solid content acid value of 85 mgKOH / g, and a weight average molecular weight of 4700 was obtained.

Synthesis example A-4)
In a 300 mL separable flask equipped with a stirrer and reflux condenser, EDGAC 83.5 g, organic acid mixture containing 85% or more of eicosan diacid (Okamura Seiyaku Co., Ltd., SL-20) 16.8 g, stearic acid 15.8 g, Acrylic acid 12.4 g, triphenylphosphine 0.53 g, and methoxyhydroquinone 0.27 g were charged, and the mixture was heated and stirred until it was dissolved at 80 ° C. while nitrogen and air (2: 1) was blown into the reaction vessel at a rate of 0.1 mL / sec. Separately, 91.8 g (114.7 g as a solution) of biphenyl aralkyl type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent 227) dissolved in 80% by mass in a 1: 1 mixture of EDGAC and Solvesso 150 After warming to 80 ° C., the mixture was put into the flask and heated and stirred at 115 ° C. for about 10 hours to react until the acid value of the reaction solution became 5 mgKOH / g or less. 22.8 g of hydrogenated trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd., HTMAn-s) was further added to the reaction product, and the mixture was heated and stirred at 100 ° C. for 4 hours in the atmosphere. The disappearance of the acid anhydride group was confirmed by FT-IR (infrared spectrophotometer). As a result, an alkali-soluble resin A-4 having a solid content of 60% by mass, a solid content acid value of 85 mgKOH / g, and a weight average molecular weight of 6800 was obtained.

Synthesis example A-5)
In a 300 mL separable flask equipped with a stirrer and a reflux condenser, EDGAC 85.6 g, organic acid mixture containing 85% or more of eicosan diacid (Okamura Seiyaku Co., Ltd., SL-20) 16.3 g, stearic acid 28.7 g, Acrylic acid 8.6 g, triphenylphosphine 0.53 g, and methoxyhydroquinone 0.27 g were charged, and the mixture was heated and stirred until it was dissolved at 80 ° C. while blowing 0.1 mL / sec of nitrogen / air (2: 1) into the reaction vessel. Separately, 83.2 g (103.9 g as a solution) of biphenyl aralkyl type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent 227) dissolved in 80% by mass in a 1: 1 mixture of EDGAC and Solvesso 150 After warming to 80 ° C., the mixture was put into the flask and heated and stirred at 115 ° C. for about 10 hours to react until the acid value of the reaction solution became 5 mgKOH / g or less. 22.8 g of hydrogenated trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd., HTMAn-s) was further added to the reaction product, and the mixture was heated and stirred at 100 ° C. for 4 hours in the atmosphere. The disappearance of the acid anhydride group was confirmed by FT-IR (infrared spectrophotometer). As a result, an alkali-soluble resin A-5 having a solid content of 60% by mass, a solid content acid value of 85 mgKOH / g, and a weight average molecular weight of 9000 was obtained.

Synthesis example A-6)
In a 300 mL separable flask equipped with a stirrer and a reflux condenser, EDGAC 87.2 g, organic acid mixture containing 85% or more of eicosanedioic acid (SL-20, Okamura Seiyaku Co., Ltd., 16.4 g), stearic acid 39.7 g, Acrylic acid (4.0 g), triphenylphosphine (0.53 g), and methoxyhydroquinone (0.27 g) were charged, and the mixture was heated and stirred until it was dissolved at 80 ° C. while blowing nitrogen and air (2: 1) into the reaction vessel at 0.1 mL / sec. Separately, 76.6 g (95.8 g as a solution) of biphenyl aralkyl type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent 227) dissolved at 80% by mass in a 1: 1 mixture of EDGAC and Solvesso 150 After warming to 80 ° C., the mixture was put into the flask and heated and stirred at 115 ° C. for about 10 hours to react until the acid value of the reaction solution became 5 mgKOH / g or less. 22.8 g of hydrogenated trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd., HTMAn-s) was further added to the reaction product, and the mixture was heated and stirred at 100 ° C. for 4 hours in the atmosphere. The disappearance of the acid anhydride group was confirmed by FT-IR (infrared spectrophotometer). As a result, an alkali-soluble resin A-6 having a solid content of 60% by mass, a solid content acid value of 85 mgKOH / g, and a weight average molecular weight of 11,000 was obtained.

Synthesis example A-7)
In a 300 mL separable flask equipped with a stirrer and a reflux condenser, 87.2 g of EDGAC, 33.5 g of distilled dimer acid (C36) (manufactured by Arizona Chemical, UNIDYM14), 16.8 g of stearic acid, 8.5 g of acrylic acid, 0.53 g of triphenylphosphine Then, 0.27 g of methoxyhydroquinone was charged, and the mixture was heated and stirred until it was dissolved at 80 ° C. while blowing nitrogen and air (2: 1) into the reaction vessel at 0.1 mL / sec. Separately, 78.0 g (97.6 g as a solution) of biphenyl aralkyl type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent 227) dissolved in 80% by mass in a 1: 1 mixture of EDGAC and Solvesso 150 After warming to 80 ° C., the mixture was put into the flask and heated and stirred at 115 ° C. for about 10 hours to react until the acid value of the reaction solution became 5 mgKOH / g or less. 22.8 g of hydrogenated trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd., HTMAn-s) was further added to the reaction product, and the mixture was heated and stirred at 100 ° C. for 4 hours in the atmosphere. The disappearance of the acid anhydride group was confirmed by FT-IR (infrared spectrophotometer). As a result, an alkali-soluble resin A-7 having a solid content of 60% by mass, a solid content acid value of 85 mgKOH / g, and a weight average molecular weight of 13100 was obtained.

Synthesis example A-8)
In a 300 mL separable flask equipped with a stirrer and a reflux condenser, EDGAC 86.3 g, organic acid mixture containing 85% or more of eicosan diacid (Okamura Seiyaku Co., Ltd., SL-20) 16.1 g, behenic acid 32.1 g, 8.3 g of acrylic acid, 0.53 g of triphenylphosphine, and 0.27 g of methoxyhydroquinone were charged, and the mixture was heated and stirred until it was dissolved at 80 ° C. while blowing 0.1 mL / sec of nitrogen / air (2: 1) into the reaction vessel. Separately, 80.3 g (100.3 g as a solution) of biphenylaralkyl type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent 227) dissolved in 80% by mass in a 1: 1 mixture of EDGAC and Solvesso 150 After warming to 80 ° C., the mixture was put into the flask and heated and stirred at 115 ° C. for about 10 hours to react until the acid value of the reaction solution became 5 mgKOH / g or less. 22.8 g of hydrogenated trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd., HTMAn-s) was further added to the reaction product, and the mixture was heated and stirred at 100 ° C. for 4 hours in the atmosphere. The disappearance of the acid anhydride group was confirmed by FT-IR (infrared spectrophotometer). As a result, an alkali-soluble resin A-8 having a solid content of 60% by mass, a solid content acid value of 85 mgKOH / g, and a weight average molecular weight of 12000 was obtained.

Synthesis example A-9)
In a 300 mL separable flask equipped with a stirrer and a reflux condenser, EDGAC 87.5 g, organic acid mixture containing 85% or more of eicosan diacid (Okamura Seiyaku Co., Ltd., SL-20) 17.2 g, stearic acid 19.6 g, Charge 20.4g of behenic acid, 4.1g of acrylic acid, 0.53g of triphenylphosphine and 0.27g of methoxyhydroquinone, and heat until dissolved at 80 ° C while blowing 0.1mL / sec of nitrogen and air (2: 1) into the reaction vessel. Stir. Separately, 75.5 g (94.4 g as a solution) of biphenylaralkyl type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent 227) dissolved in 80% by mass in a 1: 1 mixture of EDGAC and Solvesso 150 After warming to 80 ° C., the mixture was put into the flask and heated and stirred at 115 ° C. for about 10 hours to react until the acid value of the reaction solution became 5 mgKOH / g or less. 22.7 g of hydrogenated trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd., HTMAn-s) was further added to the reaction product, and the mixture was heated and stirred at 100 ° C. for 4 hours in the atmosphere. The disappearance of the acid anhydride group was confirmed by FT-IR (infrared spectrophotometer). As a result, an alkali-soluble resin A-9 having a solid content of 60% by mass, a solid content acid value of 85 mgKOH / g, and a weight average molecular weight of 13,500 was obtained.

Synthesis example A-10)
In a 300 mL separable flask equipped with a stirrer and a reflux condenser, EDGAC 87.0 g, organic acid mixture containing 85% or more of eicosanedioic acid (SL-20) manufactured by Okamura Seiyaku Co., Ltd., 15.2 g, stearic acid 12.6 g, Charge 25.1 g of behenic acid, 6.4 g of acrylic acid, 0.53 g of triphenylphosphine, and 0.27 g of methoxyhydroquinone, and heat until dissolved at 80 ° C while blowing 0.1 mL / sec of nitrogen and air (2: 1) into the reaction vessel. Stir. Separately, 77.7 g (97.2 g as a solution) of biphenyl aralkyl type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent 227) dissolved in 80% by mass in a 1: 1 mixture of EDGAC and Solvesso 150 After warming to 80 ° C., the mixture was put into the flask and heated and stirred at 115 ° C. for about 10 hours to react until the acid value of the reaction solution became 5 mgKOH / g or less. 22.7 g of hydrogenated trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd., HTMAn-s) was further added to the reaction product, and the mixture was heated and stirred at 100 ° C. for 4 hours in the atmosphere. The disappearance of the acid anhydride group was confirmed by FT-IR (infrared spectrophotometer). As a result, an alkali-soluble resin A-10 having a solid content of 60% by mass, a solid content acid value of 85 mgKOH / g, and a weight average molecular weight of 9900 was obtained.

Synthesis example A-11)
In a 300 mL separable flask equipped with a stirrer and a reflux condenser, EDGAC 87.0 g, 16.3 g of an organic acid mixture containing 80% or more of 8-ethyloctadecanedioic acid (SB-20, manufactured by Okamura Seiyaku Co., Ltd.), stearic acid 28.7 g, 8.6 g of acrylic acid, 0.53 g of triphenylphosphine, and 0.27 g of methoxyhydroquinone were charged and heated and stirred until dissolved at 80 ° C. while blowing 0.1 mL / sec of nitrogen / air (2: 1) into the reaction vessel. . Separately, 83.2 g (103.9 g as a solution) of biphenyl aralkyl type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent 227) dissolved in 80% by mass in a 1: 1 mixture of EDGAC and Solvesso 150 After warming to 80 ° C., the mixture was put into the flask and heated and stirred at 115 ° C. for about 10 hours to react until the acid value of the reaction solution became 5 mgKOH / g or less. 22.8 g of hydrogenated trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd., HTMAn-s) was further added to the reaction product, and the mixture was heated and stirred at 100 ° C. for 4 hours in the atmosphere. The disappearance of the acid anhydride group was confirmed by FT-IR (infrared spectrophotometer). As a result, an alkali-soluble resin A-11 having a solid content of 60% by mass, a solid content acid value of 85 mgKOH / g, and a weight average molecular weight of 10100 was obtained.

Synthesis Example A-12)
In a 300 mL separable flask equipped with a stirrer and a reflux condenser, 15.5 g of organic acid mixture (SB-20, Okamura Seiyaku Co., Ltd., SB-20) containing 86.4 g of EDGAC and 80% or more of 8-ethyloctadecanedioic acid, behenic acid 33.0 g, 8.3 g of acrylic acid, 0.53 g of triphenylphosphine, and 0.27 g of methoxyhydroquinone were charged, and the mixture was heated and stirred until it was dissolved at 80 ° C. while blowing 0.1 mL / sec of nitrogen / air (2: 1) into the reaction vessel. . Separately, 80.0 g (99.9 g as a solution) of biphenylaralkyl type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent 227) dissolved in 80% by mass in a 1: 1 mixture of EDGAC and Solvesso 150 After warming to 80 ° C., the mixture was put into the flask and heated and stirred at 115 ° C. for about 10 hours to react until the acid value of the reaction solution became 5 mgKOH / g or less. 22.8 g of hydrogenated trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd., HTMAn-s) was further added to the reaction product, and the mixture was heated and stirred at 100 ° C. for 4 hours in the atmosphere. The disappearance of the acid anhydride group was confirmed by FT-IR (infrared spectrophotometer). As a result, an alkali-soluble resin A-12 having a solid content of 60% by mass, a solid content acid value of 85 mgKOH / g, and a weight average molecular weight of 9900 was obtained.

Synthesis example A-13)
In a 300mL separable flask equipped with a stirrer and reflux condenser, EDGAC 89.4g, Dimer dimer acid (C36) (Arizona Chemical, UNIDYM14) 25.5g, Behenic acid 39.6g, Acrylic acid 3.7g, Triphenylphosphine 0.53g Then, 0.27 g of methoxyhydroquinone was charged, and the mixture was heated and stirred until it was dissolved at 80 ° C. while blowing nitrogen and air (2: 1) into the reaction vessel at 0.1 mL / sec. Separately, 68.1 g (99.9 g as a solution) of biphenyl aralkyl type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent 227) dissolved in 80% by mass in a 1: 1 mixture of EDGAC and Solvesso 150 After warming to 80 ° C., the mixture was put into the flask and heated and stirred at 115 ° C. for about 10 hours to react until the acid value of the reaction solution became 5 mgKOH / g or less. 22.7 g of hydrogenated trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd., HTMAn-s) was further added to the reaction product, and the mixture was heated and stirred at 100 ° C. for 4 hours in the atmosphere. The disappearance of the acid anhydride group was confirmed by FT-IR (infrared spectrophotometer). As a result, an alkali-soluble resin A-13 having a solid content of 60% by mass, a solid content acid value of 85 mgKOH / g, and a weight average molecular weight of 10,200 was obtained.

Synthesis example A-14)
In a 300 mL separable flask equipped with a stirrer and a reflux condenser, EDGAC 83.9 g, Dimer dimer acid (C36) (Arizona Chemical, UNIDYM14) 32.9 g, Acrylic acid 14.2 g, Triphenylphosphine 0.53 g, Methoxyhydroquinone 0.27 g The mixture was heated and stirred until dissolved at 80 ° C. while blowing 0.1 mL / sec of nitrogen / air (2: 1) into the reaction vessel. Separately, 89.9 g (112.3 g as a solution) of dicyclopentadiene type epoxy resin (manufactured by DIC Corporation, HP-7200H, epoxy equivalent 280) dissolved in 80% by mass in a 1: 1 mixture of EDGAC and Solvesso 150 After warming to 0 ° C., the mixture was put into the above flask and heated and stirred at 115 ° C. for about 10 hours to react until the acid value of the reaction solution became 5 mgKOH / g or less. 22.7 g of hydrogenated trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd., HTMAn-s) was further added to the reaction product, and the mixture was heated and stirred at 100 ° C. for 4 hours in the atmosphere. The disappearance of the acid anhydride group was confirmed by FT-IR (infrared spectrophotometer). As a result, an alkali-soluble resin A-14 having a solid content of 60% by mass, a solid content acid value of 85 mgKOH / g, and a weight average molecular weight of 8200 was obtained.

Synthesis example A-15)
In a 300 mL separable flask equipped with a stirrer and reflux condenser, EDGAC 84.1g, Distilled dimer acid (C36) (Arizona Chemical, UNIDYM14) 33.0g, Acrylic acid 14.4g, Triphenylphosphine 0.53g, Methoxyhydroquinone 0.27g The mixture was heated and stirred until dissolved at 80 ° C. while blowing 0.1 mL / sec of nitrogen / air (2: 1) into the reaction vessel. Separately, 89.2 g (111.5 g as a solution) of biphenylaralkyl type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent 227) dissolved in 80% by mass in a 1: 1 mixture of EDGAC and Solvesso 150 After warming to 80 ° C., the mixture was put into the flask and heated and stirred at 115 ° C. for about 10 hours to react until the acid value of the reaction solution became 5 mgKOH / g or less. To this reaction product, 23.0 g of succinic anhydride was further added, and the mixture was heated and stirred at 100 ° C. for 4 hours in the atmosphere. The disappearance of the acid anhydride group was confirmed by FT-IR (infrared spectrophotometer). As a result, an alkali-soluble resin A-15 having a solid content of 60% by mass, a solid content acid value of 85 mgKOH / g, and a weight average molecular weight of 10100 was obtained.

Synthesis example A-16)
In a 300 mL separable flask equipped with a stirrer and a reflux condenser, EDGAC 84.0 g, organic acid mixture containing 85% eicosan diacid (Okamura Seiyaku Co., Ltd., SL-20) 16.8 g, stearic acid 46.2 g, acrylic 1.1 g of acid, 0.53 g of triphenylphosphine, and 0.27 g of methoxyhydroquinone were charged, and the mixture was heated and stirred until it was dissolved at 80 ° C. while blowing 0.1 mL / sec of nitrogen / air (2: 1) into the reaction vessel. Separately, 72.6 g (90.8 g as a solution) of biphenyl aralkyl type epoxy resin (Nippon Kayaku Co., Ltd., NC-3000, epoxy equivalent 227) dissolved in 80% by mass in a 1: 1 mixture of EDGAC and Solvesso 150 After warming to 80 ° C., the mixture was put into the flask and heated and stirred at 115 ° C. for about 10 hours to react until the acid value of the reaction solution became 5 mgKOH / g or less. 22.8 g of hydrogenated trimellitic anhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd., HTMAn-s) was further added to the reaction product, and the mixture was heated and stirred at 100 ° C. for 4 hours in the atmosphere. The disappearance of the acid anhydride group was confirmed by FT-IR (infrared spectrophotometer). As a result, an alkali-soluble resin A-16 having a solid content of 60% by mass, a solid content acid value of 85 mgKOH / g, and a weight average molecular weight of 11,000 was obtained.

  Regarding the alkali-soluble resins of Synthesis Examples A-1 to A-16, the blending amount (preparation amount) of raw materials (unit: mass (g)) and double bond equivalent are summarized in Table 1 below.

Examples 1-18, Comparative Examples 1-3
The components shown in Table 2 below are blended at the blending ratios shown in Table 2 below, mixed and dispersed at room temperature using three rolls, and used in Examples 1 to 18 and Comparative Examples 1 to 3. A functional resin composition was prepared. In addition, the compounding quantity shown in following Table 2 represents a mass part.

The detail about each component in Table 2 is as follows.
Alkali-soluble resin / FLX-2089: A photosensitive carboxyl group-containing resin solution using a urethane-modified epoxy resin manufactured by Nippon Kayaku Co., Ltd.
ZFR-1122: Nippon Kayaku Co., Ltd., carboxyl-modified bisphenol F type epoxy acrylate resin solution.
ZCR-1601: An acid anhydride-modified resin solution of biphenyl novolac type epoxy acrylate manufactured by Nippon Kayaku Co., Ltd.

Photopolymerization initiator Irgacure 907: Ciba Specialty Chemicals, Inc., 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one.
SPEEDCURE DETX: 2,4-diethylthioxanthone manufactured by Nippon Shibel Hegner Co., Ltd.
SPEEDCURE TPO: 2,4,6-trimethylbenzoyl diphenylphosphine oxide manufactured by Nippon Siber Hegner Co., Ltd.
OXE-02: manufactured by BASF, ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] −, 1- (O-acetyloxime).

Thermosetting compound: NC-3000: manufactured by Nippon Kayaku Co., Ltd., biphenyl aralkyl type epoxy resin (epoxy equivalent 227).
-YX4000: manufactured by Mitsubishi Chemical Corporation, tetramethylbiphenol type epoxy resin.

Photo-curing compound / SP4621BC: manufactured by Showa Denko KK, cresol novolac type epoxy acrylate resin (solid content: 70%), diethylene glycol monoethyl ether acetate 15%, remainder Solvesso.
-KRM8296: Daicel Tech Co., Ltd. urethane acrylate resin.
Karayad R-684: Nippon Kayaku Co., Ltd. dicyclopentadiene dimethanol diacrylate.
Organic filler Art Pearl JB-8000: manufactured by Negami Kogyo Co., Ltd.
Inorganic ion exchanger (ion catcher)
IXE-100: manufactured by Toagosei Co., Ltd., Zr-based cation exchanger, median diameter 1.0 μm.
Colorant Lionol Blue FG-7351: Toyo Ink Co., Ltd., phthalocyanine pigment.
Antifoaming agent KS-66: Silicone defoaming agent manufactured by Shin-Etsu Chemical Co., Ltd.

Test piece preparation process The photosensitive resin composition prepared as mentioned above was applied as follows, and the test piece was created.
Photosensitive resin compositions prepared by screen printing after surface treatment with a dilute sulfuric acid (3%) substrate for a flexible wiring board having a circuit pattern formed on a polyimide film (Kapton 100H manufactured by Toray DuPont Co., Ltd.) After coating, preliminary drying was performed at 80 ° C. for 20 minutes in a BOX furnace. After the preliminary drying, a negative film having a pattern in which light is transmitted except for the land of the circuit pattern is brought into close contact with the coating film, and ultraviolet rays are applied to the negative film up to 500 mJ / cm ² using an exposure device (OMW HMW-680GW). Exposed. Then, after developing with 1% sodium carbonate developer at 30 ° C., a cured coating film was formed on the substrate by curing at 150 ° C. for 60 minutes in a BOX furnace. Test pieces of Examples 1 to 3 were obtained. The thickness of the cured coating film was 20 to 23 μm.

Evaluation item (1) Dryness to touch The negative film was brought into contact with the coating film after preliminary drying, and the sticking property of the coating film to the negative film after exposure was evaluated.
Evaluation was carried out in three stages: ◯: no sticking, Δ: trace of sticking on the coating film remaining, x: coating of the negative film after peeling off the negative film.

(2) Sensitivity Step sensitivity tablet (21 stages of Kodak) is installed on the substrate that has been subjected to the preliminary drying process in the same manner as the above test piece preparation process, and the amount of ultraviolet light (main peak wavelength 365 nm) irradiated through this step tablet. Was irradiated to 300 mJ / cm ² using an integrating light meter manufactured by Oak Manufacturing Co., Ltd., and was used as a test piece. The test piece was developed using a 1% aqueous sodium carbonate solution at a spray pressure of 2.0 kg / cm ² for 60 seconds. Of the exposed portion, the portion not removed by development was represented by a number (number of steps). The larger the number of steps, the better the photosensitive characteristics.
The evaluation was performed in three stages: ◯: 8 steps or more, Δ: 6-7 steps, x: 5 steps or less.

(3) Developability The presence or absence of a residue on the circuit pattern and the polyimide film after the development in the test piece preparation step was visually evaluated.
Evaluation: ○: No residue on the circuit pattern or on the polyimide film, Δ: No residue on the circuit pattern, but a little residue on the polyimide film, ×: Residue on both the circuit pattern or the polyimide film The remaining three steps were performed.

(4) Bending property The test piece prepared in the above-mentioned test piece preparation step is repeatedly bent 180 ° by goblet folding several times, and the crack generation state of the cured coating film during 180 ° bending is visually observed and × 200 Observed with an optical microscope, the number of times that no crack was generated was measured.
The evaluation was performed in three stages: ◯: 4 times or more, Δ: 2 to 3 times, ×: 1 time or less.

(5) Warpage property After cutting out the test piece prepared in the above-mentioned test piece preparation step to 3 cm × 3 cm, place the cut out test piece gently on a horizontal table so that the top is concave, and apply no external force. Thus, the vertical distance between the four corners of the test piece and the table was measured in a straight scale, and the maximum value was adopted.
The evaluation was performed in four stages: ◎: 1 mm or less, ○: more than 1 mm to 3 mm, Δ: more than 3 mm to 5 mm, and x: more than 5 mm.

(6) Gold-plating resistance After the gold-plated test piece prepared in the above-mentioned test piece preparation step, a peeling test using a cellophane adhesive tape was performed, and the peel and discoloration of the cured coating film was visually observed to evaluate the gold plating property. .
Evaluation: ○: No peeling of the cured coating film and no discoloration, Δ: Only slight peeling or discoloration of the cured coating film is observed, ×: Peeling or discoloration of the cured coating film is clearly recognized 3 Performed in stages.

(7) Flame retardancy A vertical combustion test based on the UL94 standard was performed. Evaluation was expressed as VTM-0 to combustion based on the UL94 standard.

  The evaluation results of Examples 1 to 18 and Comparative Examples 1 to 3 are shown in Table 3 below.

  From Table 3, Examples 1 to 17 using an alkali-soluble resin modified with a fatty acid having 10 or more carbon atoms per carboxyl group, that is, the fatty acid structure introduced, are dry to touch, sensitivity, It was able to bend and reduce warping without impairing developability, gold plating resistance and flame retardancy. In Examples 3 to 13, and Examples 16 and 17 in which a linear saturated aliphatic monobasic acid structure having 18 or 22 carbon atoms per carboxyl group was introduced into the resin, the bendability was more reliably ensured. Improved. Furthermore, from Examples 14 and 15, the biphenyl aralkyl type epoxy resin has better bendability than the dicyclopentadiene type epoxy resin, and the hydrogenated trimellitic anhydride has more developability than the succinic acid. It was excellent. From Example 16 and other examples, when the double bond equivalent was 3133 g / eq or less, the dryness to touch and the sensitivity were more excellent. Further, also in Example 18 using the alkali-soluble resin having the fatty acid structure introduced therein and the alkali-soluble resin having no fatty acid structure introduced therein, dryness to touch, sensitivity, developability, gold plating resistance, and flame retardancy It was possible to bend and reduce warpage without damaging the surface.

  On the other hand, Comparative Examples 1 to 3 using only an alkali-soluble resin into which a fatty acid having 10 or more carbon atoms per carboxyl group is not introduced cannot obtain bending properties and can suppress warping. There wasn't.

  Since the photosensitive resin composition of the present invention is excellent in bendability and low warpage, and can obtain a cured product of the photosensitive resin composition having flame retardancy and insulation, for example, printed wiring boards, particularly Highly useful in the fields of FPC solder resist film and photosensitive coverlay.

Claims (10)

  a) an epoxy resin having two or more epoxy groups in one molecule; b) at least one fatty acid having 10 or more carbon atoms per carboxyl group; and c) an ethylenically unsaturated group-containing carboxylic acid. A photosensitive resin composition containing an alkali-soluble resin (A) obtained by adding d) a polybasic acid anhydride to a reaction product, and a photopolymerization initiator (B).   The photosensitive resin composition according to claim 1, wherein at least one of the fatty acids is a dibasic acid.   3. The photosensitive resin composition according to claim 1, wherein at least one of the fatty acids is a linear saturated aliphatic monobasic acid having 18 or more carbon atoms. The polybasic acid anhydride is represented by the following general formula (1)

(In the formula, R ² represents a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, an aryl group, a carboxyl group, or a hydroxyl group, and m is an integer of 1 to 3). The photosensitive resin composition of any one of Claims 1 thru | or 3 which is a compound represented by these. The epoxy resin has the following general formula (2)
(In the formula, R ¹ represents a hydrogen atom, or a linear or branched alkyl group or aryl group having 1 to 8 carbon atoms, l is an integer of 1 to 3, and n is an integer of 1 to 10. The photosensitive resin composition according to claim 1, wherein the photosensitive resin composition is a compound represented by the formula:   Furthermore, the photosensitive resin composition of any one of Claims 1 thru | or 5 containing the flame retardant (C) selected from the group which consists of a phosphorus element containing compound and aluminum hydroxide.   Furthermore, the photosensitive resin composition of any one of Claims 1 thru | or 6 containing a thermosetting compound (D).   The dry film obtained by drying the photosensitive resin composition of any one of Claims 1 thru | or 7 after apply | coating to a film.   A coating film formed by laminating a dry film obtained by applying the photosensitive resin composition according to any one of claims 1 to 7 on a film and then drying the pattern is patterned and photocured. Printed wiring board having a cured coating.   A printed wiring board having a cured film obtained by patterning and photocuring a coating film formed by applying the photosensitive resin composition according to any one of claims 1 to 7 on a substrate.