JP2019049709A - Photosensitive resin composition, dry film coated with photosensitive resin composition and printed wiring board having photocured film of photosensitive resin composition - Google Patents

Abstract

To provide: a photosensitive resin composition capable of obtaining a cured coating film having a superior line shape for preventing undercut and excellent elongation characteristics without impairing basic characteristics such as dry-to-touch property; a dry film coated with the photosensitive resin composition; and a printed wiring board having a photocured film of the photosensitive resin composition.SOLUTION: There is provided a photosensitive resin composition which comprises (A) a carboxyl group-containing photosensitive resin obtained by adding e) a polybasic acid and/or a polybasic acid anhydride to an unsaturated carboxylated epoxy resin which is a reaction product of a) an epoxy resin having two or more epoxy groups in one molecule, b) at least one saturated monocarboxylic acid having 5 to 17 carbon atoms, c) a dicarboxylic acid and d) an ethylenically unsaturated group-containing carboxylic acid and (B) a photopolymerization initiator.SELECTED DRAWING: None

Description

  The present invention provides a photosensitive resin composition having an excellent line shape and capable of obtaining a cured coating film having excellent elongation properties, a dry film coated with the photosensitive resin composition, and the photosensitive resin. The present invention relates to a printed wiring board having a photocured film of a composition.

  A protective film (for example, an insulating film) may be formed on a substrate (for example, a substrate on which a pattern of a conductor circuit is formed). Examples of the substrate on which the pattern of the conductor circuit is formed include a printed wiring board using a flexible substrate or a rigid substrate. As a protective film of a printed wiring board, the photocuring film of the photosensitive resin composition containing photosensitive resin may be used.

  With the advancement of electronic devices in recent years, electronic components are mounted at a high density on a printed wiring board, so that the protective film of the printed wiring board has a shape in which undercutting is prevented even for fine lines. In other words, it is required that the resolution be good. Further, among the printed wiring boards, flexible printed wiring boards using flexible substrates such as polyimide are required to have a flexible protective film, and therefore, excellent elongation characteristics are also required.

  Therefore, in Patent Document 1, (A) a photosensitive prepolymer having two or more unsaturated double bonds and one or more carboxyl groups in one molecule, in order to provide a cured coating film excellent in flexibility. (B) Photopolymerization resin, (C) Diluent, (D) Epoxy compound, (E) Polybutadiene having one or more internal epoxide groups in one molecule, and (F) Photosensitive resin containing polyurethane fine particles Compositions have been proposed.

  However, in Patent Document 1, there is still a room for improvement in the elongation characteristics, and there is a problem that it is not possible to sufficiently obtain an excellent line shape in which the undercut is prevented.

JP 2002-293882 A

  In view of the above-mentioned circumstances, the present invention has an excellent line shape in which undercuts are prevented without impairing basic characteristics such as dryability to the touch, and it is possible to obtain a cured coating film excellent in elongation characteristics. The present invention aims to provide a photosensitive resin composition, a dry film coated with the photosensitive resin composition, and a printed wiring board having a photocured film of the photosensitive resin composition.

  Embodiments of the present invention include (A) a) an epoxy resin having two or more epoxy groups in one molecule, b) at least one saturated monocarboxylic acid having 5 to 17 carbon atoms, and c) dicarboxylic acid d) Carboxyl group-containing photosensitivity obtained by adding e) a polybasic acid and / or a polybasic acid anhydride to an unsaturated carboxylated epoxy resin which is a reaction product with an ethylenically unsaturated group-containing carboxylic acid It is a photosensitive resin composition comprising a resin and (B) a photopolymerization initiator.

  An embodiment of the present invention is a photosensitive resin composition characterized in that the b) at least one saturated monocarboxylic acid having 5 to 17 carbon atoms is linear.

  An embodiment of the present invention is a photosensitive resin composition characterized in that the c) dicarboxylic acid contains at least one dicarboxylic acid having 6 to 20 carbon atoms.

  An embodiment of the present invention is a photosensitive resin composition characterized in that the c) dicarboxylic acid contains at least one dicarboxylic acid having 6 to 10 carbon atoms.

An aspect of the present invention is that the above e) polybasic acid and / or polybasic acid anhydride is a polybasic acid anhydride, and the polybasic acid anhydride is a compound represented by the following general formula (1)
(Wherein, 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 a compound represented by these, It is a photosensitive resin composition characterized by the above-mentioned.

  An embodiment of the present invention is a photosensitive resin composition further comprising (C) (meth) acrylate monomer.

  An aspect of the present invention is a photosensitive resin composition further comprising (D) an epoxy compound.

  An aspect of the present invention is a dry film characterized in that the photosensitive resin composition is coated on a film.

  The aspect of this invention is a printed wiring board characterized by having the photocured film which patterned the coating film formed by laminating the said dry film on the board | substrate, and patterning it.

  The aspect of this invention is a printed wiring board characterized by having a photocured film which patterned the coating film formed by apply | coating the said photosensitive resin composition on a board | substrate.

  According to an aspect of the present invention, a photosensitive resin composition comprising (A) a carboxyl group-containing photosensitive resin and (B) a photopolymerization initiator, wherein (A) a carboxyl group-containing photosensitive resin is A) an epoxy resin having two or more epoxy groups in one molecule, b) at least one saturated monocarboxylic acid having 5 to 17 carbon atoms, c) a dicarboxylic acid, and d) an ethylenically unsaturated group containing Excellent transparency and touch by having a chemical structure obtained by adding e) a polybasic acid and / or a polybasic acid anhydride to an unsaturated carboxylated epoxy resin which is a reaction product with a carboxylic acid It is possible to obtain a photosensitive resin composition having drying properties, and to obtain a cured coating film excellent in resolution and excellent in elongation characteristics by being able to obtain an excellent line shape in which undercut is prevented. Can.

  In addition, according to an aspect of the present invention, a medium-chain to long-chain monocarboxylic acid (saturated monocarboxylic acid having 5 to 17 carbon atoms) having a structure excellent in transparency, elongation characteristics, insulation reliability, and hydrophobicity. Together with an ethylenically unsaturated group-containing carboxylic acid and added to an epoxy resin having two or more epoxy groups in one molecule, photocurability, transparency, elongation properties, insulation reliability, combustion resistance and hydrophobicity It is possible to form a cured coating film having excellent properties. Further, by adding a polybasic acid and / or a polybasic acid anhydride and introducing a carboxyl group into the resin, it can be solubilized in a weakly alkaline aqueous solution (for example, an aqueous solution of sodium carbonate, an aqueous solution of potassium carbonate, etc.) And developability can be imparted to the resin composition.

  According to the aspect of the present invention, by adding a dicarboxylic acid to an epoxy resin having two or more epoxy groups in one molecule, different epoxy groups of epoxy resins which are constituent components of a carboxyl group-containing photosensitive resin are By mutually bonding via the said dicarboxylic acid, the comparatively rigid frame which an epoxy resin has becomes the structure bridge | crosslinked by the covalent bond by the frame | skeleton which has flexibility derived from dicarboxylic acid. Thereby, elongation property can be provided to the cured coating film of the photosensitive resin composition of this invention. In addition, since a relatively low molecular weight epoxy resin can be adjusted to an appropriate molecular weight by introducing a dicarboxylic acid into a carboxyl group-containing photosensitive resin, it is possible to dry the touch after drying while maintaining the alkali developability. It can be set as the photosensitive resin composition used as the cured coating film excellent in nature.

  According to the aspect of the present invention, the transparency of the photosensitive resin composition is further improved by containing a medium- to long-chain dicarboxylic acid having 6 to 10 carbon atoms as the dicarboxylic acid, and the undercut is further ensured. It is possible to obtain a cured coating having a better line shape (i.e., having excellent resolution) prevented by Moreover, the touch-drying property of the photosensitive resin composition is further improved by containing a medium- to long-chain dicarboxylic acid having 6 to 10 carbon atoms as the dicarboxylic acid.

  Next, the photosensitive resin composition of the present invention will be described in detail. The photosensitive resin composition of the present invention comprises (A) a) an epoxy resin having two or more epoxy groups in one molecule, and b) at least one saturated monocarboxylic acid having 5 to 17 carbon atoms and c. E) Carboxyl obtained by adding e) a polybasic acid and / or a polybasic acid anhydride to an unsaturated carboxylated epoxy resin which is a reaction product of a dicarboxylic acid and d) an ethylenically unsaturated group-containing carboxylic acid It contains a group-containing photosensitive resin and (B) a photopolymerization initiator. The above components are as follows.

(A) Carboxyl group-containing photosensitive resin a) Epoxy resin having two or more epoxy groups in one molecule If an epoxy resin having two or more epoxy groups in one molecule is a bifunctional or more epoxy resin Either can be used. The epoxy equivalent of the epoxy resin having two or more epoxy groups in one molecule is not particularly limited, but the upper limit thereof is a decrease in the introduction ratio of the ethylenically unsaturated group-containing carboxylic acid, the saturated monocarboxylic acid and the dicarboxylic acid 1000 g / eq is preferable, 500 g / eq is more preferable, and 400 g / eq is particularly preferable, from the viewpoint of preventing a decrease in photosensitivity and elongation properties due to the above. On the other hand, the lower limit thereof is preferably 100 g / eq, particularly preferably 200 g / eq, in view of heat resistance and mechanical strength.

  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, phenol aralkyl type epoxy resin, dicyclopentadiene Type epoxy resin, rubber modified epoxy resin such as silicone modified epoxy resin, ε-caprolactone modified epoxy resin, bisphenol novolac epoxy resin such as bisphenol A type, bisphenol F type, bisphenol AD type, cresol novolac such as о-cresol novolac type Type epoxy resin, cycloaliphatic polyfunctional epoxy resin, glycidyl ester polyfunctional epoxy resin, glycidyl amine polyfunctional epoxy resin, heterocyclic polyfunctional epoxy resin, bisphenol modified epoxy resin Borac type epoxy resin, multifunctional modified novolac type epoxy resin, condensate type epoxy resin of phenol and aromatic aldehyde having phenolic hydroxyl group, epoxy resin having fluorene skeleton, epoxy resin having adamantane skeleton introduced be able to. In addition, those resins into which a halogen atom such as Br or Cl is introduced may be used.

  Among these, from the viewpoint of the photosensitivity of the cured product of the photosensitive resin composition, elongation characteristics and insulation reliability, biphenyl aralkyl type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, phenol aralkyl type epoxy resin Biphenyl aralkyl type epoxy resin, for example, the following general formula (2) because

(Wherein, R ¹ represents a hydrogen atom, or a linear or branched alkyl 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) Particularly preferred are biphenylaralkyl type epoxy resins and phenolaralkyl type epoxy resins represented by

Commercially available epoxy resins having two or more epoxy groups in one molecule include, for example, NC-3000 (Nippon Kayaku Co., Ltd., biphenyl aralkyl wherein R ^{1 in the} general formula (2) is a hydrogen atom) Type epoxy resin), HP-7200H (DIC Corporation, dicyclopentadiene type epoxy resin), NC-7000 and NC-7300 (Nippon Kayaku Co., Ltd., naphthalene type epoxy resin), NC-2000 (Nippon Kayaku Co., Ltd.) And phenol aralkyl type epoxy resins). The epoxy resins having two or more epoxy groups in one molecule described above may be used alone or in combination of two or more.

b) Saturated monocarboxylic acid having 5 to 17 carbon atoms A saturated monocarboxylic acid having 5 to 17 carbon atoms is, for example, a saturated monocarboxylic acid having a hydrocarbon group having 5 to 17 carbon atoms . The saturated monocarboxylic acid having 5 to 17 carbon atoms includes fatty acids having 5 to 17 carbon atoms which are monobasic acids.

  The saturated monocarboxylic acid having 5 to 17 carbon atoms reacts with the epoxy group of the epoxy resin having two or more epoxy groups in one molecule, and the transparency derived from the above-mentioned saturated monocarboxylic acid in the resin, Medium- to long-chain hydrocarbon structures with excellent flexibility and insulation reliability are introduced. Thereby, the cured coating film of the photosensitive resin composition has excellent line shape by which undercut is prevented by imparting excellent transparency to the photosensitive resin composition, and further, the photosensitive resin composition is obtained. The cured coating film of the object can obtain excellent elongation characteristics, insulation reliability and the like. In addition, the introduction of a medium- to long-chain hydrocarbon structure derived from the above-mentioned saturated monocarboxylic acid imparts excellent touch-drying property to the photosensitive resin composition.

  As a saturated monocarboxylic acid having 5 to 17 carbon atoms, a saturated monocarboxylic acid having a cyclic aliphatic hydrocarbon group, a saturated monocarboxylic acid having a linear aliphatic hydrocarbon group, a branched fatty acid Any saturated monocarboxylic acid having a group hydrocarbon group may be used. Among them, the cohesion that is considered to be derived from the hydrophobic bond of the linear saturated aliphatic chain is generated in the coating after drying, and the coating after predrying not only has further excellent contact dryness. And, by having a structure of a linear saturated aliphatic chain which is more excellent in flexibility, the cured coating film is linear from the viewpoint of having more excellent elongation characteristics and improving transparency and elongation characteristics in a well-balanced manner. Preferred are saturated monocarboxylic acids having an aliphatic hydrocarbon group of

  The carbon number of the saturated monocarboxylic acid is not particularly limited as long as it is in the range of 5 to 17. However, the carbon number of 5 to 12 is preferable from the viewpoint of improving the transparency and the elongation characteristics in a balanced manner.

  Examples of saturated monocarboxylic acids having 5 to 17 carbon atoms include pentanoic acid (C5), hexanoic acid (C6), heptanoic acid (C7), octanoic acid (C8), nonanoic acid (C9), decanoic acid C10), dodecanoic acid (C12), tetradecanoic acid (C14), hexadecanoic acid (C16), heptadecanoic acid (C17) and the like. These may be used alone or in combination of two or more.

  The proportion (feed ratio) of the saturated monocarboxylic acid having 5 to 17 carbon atoms in the carboxyl group-containing photosensitive resin (solid content) is not particularly limited, but the lower limit thereof is elongation characteristics and insulation reliability. 5.0 mass% is preferable from the point of further improving, and 8.0 mass% is especially preferable from the point of further improving elongation characteristics. On the other hand, the upper limit value thereof is an alkali while ensuring the introduction amount of polybasic acid and / or polybasic acid anhydride while ensuring the introduction amount of the ethylenically unsaturated group-containing carboxylic acid to surely obtain photosensitivity. 20% by mass is preferable, and 18% by mass is particularly preferable, from the viewpoint of reliably obtaining developability.

c) Dicarboxylic acid Dicarboxylic acid reacts with the epoxy group of the epoxy resin having two or more epoxy groups in one molecule to introduce the hydrocarbon structure of dicarboxylic acid into the epoxy resin, and the epoxy different from the above epoxy resin Groups can be linked to each other through dicarboxylic acids, so that the relatively rigid skeleton of the epoxy resin can be configured to be covalently crosslinked by a dicarboxylic hydrocarbon-derived flexible hydrocarbon structure. It imparts to the epoxy resin a structure excellent in the elongation properties, transparency and touch-drying properties of the cured coating. In addition, by using a saturated monocarboxylic acid and a dicarboxylic acid in combination, it is possible to adjust an epoxy resin having a relatively low molecular weight to an appropriate molecular weight while having flexibility. Therefore, it can be set as the photosensitive resin composition which becomes a cured coating film excellent in the touch-drying property after drying, maintaining flexibility and alkali developability.

  As a dicarboxylic acid, for example, a saturated dicarboxylic acid having an acyclic saturated aliphatic hydrocarbon group, an unsaturated dicarboxylic acid having an acyclic unsaturated aliphatic hydrocarbon group, a saturated having a cyclic saturated aliphatic hydrocarbon group Preferred are dicarboxylic acids and unsaturated dicarboxylic acids having cyclic unsaturated aliphatic hydrocarbon groups. Moreover, as a saturated dicarboxylic acid having an acyclic saturated aliphatic hydrocarbon group, a linear aliphatic hydrocarbon group or a branched aliphatic hydrocarbon group having two or less side chains having 2 or less carbon atoms Particularly preferred are saturated dicarboxylic acids having As an unsaturated dicarboxylic acid having an acyclic unsaturated aliphatic hydrocarbon group, a linear aliphatic hydrocarbon group or a branched aliphatic hydrocarbon group having two or less side chains having 2 or less carbon atoms Particularly preferred are unsaturated dicarboxylic acids having

  From the above, dicarboxylic acids include saturated fatty acids which are dibasic acids and unsaturated fatty acids which are dibasic acids.

  The carbon number of the dicarboxylic acid is not particularly limited, but in the case of a dicarboxylic acid having an acyclic aliphatic hydrocarbon group, the lower limit thereof is preferably 5 carbons from the viewpoint of reliably obtaining elongation characteristics, and particularly preferably 6 carbons. preferable. On the other hand, the upper limit of the carbon number of the dicarboxylic acid having an acyclic aliphatic hydrocarbon group is an excellent line shape in which the transparency of the photosensitive resin composition is surely improved and the undercut is surely prevented. The carbon number is preferably 20 from the viewpoint that a cured coating film having the above can be obtained, and the touch-drying property of the photosensitive resin composition is also surely improved, and the transparency of the photosensitive resin composition is further improved. From the viewpoint of obtaining a cured coating film having an excellent line shape and further improving the touch-drying property of the photosensitive resin composition, the carbon number is more preferably 12 and particularly preferably 10. In the dicarboxylic acid having a cyclic aliphatic hydrocarbon group, the lower limit thereof is preferably 6 carbon atoms, and particularly preferably 7 carbon atoms, from the viewpoint of reliably obtaining elongation characteristics. On the other hand, the upper limit of the carbon number of the dicarboxylic acid having a cyclic aliphatic hydrocarbon group is an excellent line shape in which the transparency of the photosensitive resin composition is surely improved and the undercut is surely prevented. The cured coating film can be obtained, and the carbon number of 20 is preferable from the viewpoint of surely improving the touch-drying property of the photosensitive resin composition, and the transparency of the photosensitive resin composition is further improved, which is more excellent. The cured coating film having the line shape can be obtained, and from the viewpoint of further improving the touch-drying property of the photosensitive resin composition, the carbon number is more preferably 12 and particularly preferably 10.

The dicarboxylic acid is, for example, the following general formula (3)
HOOC-R ³ -COOH (3)
(Wherein, R ³ represents an acyclic saturated aliphatic hydrocarbon group having ^{3 to} 18 carbon atoms, an acyclic unsaturated aliphatic hydrocarbon group having 3 to 18 carbon atoms, or a cyclic saturated aliphatic hydrocarbon group Or a dicarboxylic acid compound represented by a C 4-18 aliphatic hydrocarbon group having a cyclic unsaturated aliphatic hydrocarbon group (preferably having one cyclic aliphatic hydrocarbon group) Is preferred.

  Examples of the compound represented by the general formula (3) include dicarboxylic acids having an acyclic aliphatic hydrocarbon group, such as pentanedioic acid (C5), adipic acid (C6), suberic acid (C8) and sebacic acid (C10), dodecanedioic acid (C12), tetradecanedioic acid (C14), hexadecanedioic acid (C16), ethyloctadecanedioic acid (C20), eicosanedioic acid (C20), dicarboxylic acids such as eicosadiene diacid (C20) Can be mentioned. Moreover, as dicarboxylic acids having a cyclic aliphatic hydrocarbon group, for example, dicarboxylic acids such as cyclobutanedicarboxylic acid (C6), cyclopentanedicarboxylic acid (C7), cyclohexanedicarboxylic acid (C8) and the like can be mentioned. These may be used alone or in combination of two or more.

  The proportion (feed ratio) of the dicarboxylic acid in the carboxyl group-containing photosensitive resin (solid content) is not particularly limited, but the lower limit is 2.0% by mass from the viewpoint of further improving the elongation characteristics and insulation reliability. Is preferred, and 3.0% by mass is particularly preferred from the viewpoint of further improving the elongation properties. On the other hand, the upper limit value thereof is an alkali while ensuring the introduction amount of polybasic acid and / or polybasic acid anhydride while ensuring the introduction amount of the ethylenically unsaturated group-containing carboxylic acid to surely obtain photosensitivity. From the viewpoint of reliably obtaining developability, 15% by mass is preferable, and 10% by mass is particularly preferable.

  The reaction method of an epoxy resin having two or more epoxy groups in one molecule, and at least one saturated monocarboxylic acid having 5 to 17 carbon atoms and a dicarboxylic acid may be a known method, for example, the above-mentioned epoxy The reaction method which heats resin and said carboxylic acid in a suitable diluent is mentioned.

d) Ethylenically unsaturated group-containing carboxylic acid The ethylenically unsaturated group-containing carboxylic acid reacts with the epoxy group of the epoxy resin having two or more epoxy groups in one molecule, and the epoxy resin is reacted with a photopolymerization initiator. Introduce a photocurable group that can be polymerized by the free radicals generated. The ethylenically unsaturated group-containing carboxylic acid is not particularly limited as long as it imparts photocurability to an epoxy resin, and examples thereof include acrylic acid, methacrylic acid, β-acryloxypropionic acid, and ω-carboxy-polycaprolactone. -(Meth) acrylic acid, crotonic acid, cinnamic acid and the like, and carboxylic acids capable of introducing an acryloyl group or methacryloyl group into an epoxy resin can be mentioned. 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 proportion (feed ratio) of the ethylenically unsaturated group-containing carboxylic acid in the carboxyl group-containing photosensitive resin (solid content) is not particularly limited, but the lower limit thereof is 2.0 mass from the point of further improving the sensitivity. % Is preferable, and 3.0% by mass is particularly preferable. On the other hand, the upper limit thereof improves elongation characteristics and insulation reliability by maintaining the introduction amount of saturated monocarboxylic acid and dicarboxylic acid having 5 to 17 carbon atoms, and further, polybasic acid and / or polybasic acid 10 mass% is preferable from the point which maintains the introduction amount of a basic acid anhydride and obtains alkali developability reliably, and 8.0 mass% is especially preferable.

  The method for reacting the epoxy resin having two or more epoxy groups in one molecule with the ethylenically unsaturated group-containing carboxylic acid is not particularly limited. For example, the above-mentioned epoxy resin and ethylenically unsaturated group-containing carboxylic acid are suitable A reaction method of heating in a diluent may be mentioned.

d) Polybasic acids, polybasic acid anhydrides Polybasic acids, polybasic acid anhydrides, hydroxyl groups formed by the reaction of the epoxy resin with saturated monocarboxylic acids having 5 to 17 carbon atoms and dicarboxylic acids, and A free carboxyl group is introduced into the epoxy resin in reaction with the hydroxyl group generated by the reaction with the ethylenically unsaturated group-containing carboxylic acid. The alkali developability is imparted by introducing a carboxyl group into the photosensitive resin. The polybasic acid and polybasic acid anhydride to be used are not particularly limited, and either saturated or unsaturated one may be used. Examples of polybasic acids include dicarboxylic acids, tricarboxylic acids, and carboxylic acids having four or more carboxyl groups. Examples of polybasic acids include succinic acid, maleic acid, adipic acid, citric acid, phthalic acid, tetrahydrophthalic acid, 3-methyltetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, 3-ethyltetrahydrophthalic acid, 4-ethyltetrahydrophthalic acid Ethyl tetrahydrophthalic acid, hexahydrophthalic acid, 3-methylhexahydrophthalic acid, 4-methylhexahydrophthalic acid, 3-ethylhexahydrophthalic acid, 4-ethylhexahydrophthalic acid, methyltetrahydrophthalic acid, methylhexahydro Phthalic acid, endomethylene tetrahydrophthalic acid, methyl endomethylene tetrahydrophthalic acid, trimellitic acid, trimellitic acid derivatives, pyromellitic acid, diglycolic acid and the like can be mentioned. As polybasic acid anhydride, the anhydride of the said polybasic acid is mentioned.

Among the polybasic acids and polybasic acid anhydrides, polybasic acid anhydrides are preferred from the viewpoint of the reaction efficiency with the above hydroxyl groups formed in the epoxy resin, that is, the ease of introduction of free carboxylic acids, and polybasic acid anhydrides From the viewpoint of alkali developability, the following general formula (1)
(Wherein, 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 is preferable.

  The compound represented by the general formula (1) is a compound having a hydroxyl group formed by the reaction of a saturated monocarboxylic acid having 5 to 17 carbon atoms, a dicarboxylic acid or a carboxylic acid having an ethylenic unsaturated group with an epoxy group The acid anhydride group reacts with the acid anhydride group to be introduced into the resin skeleton through an ester bond. At this time, the compound represented by the general formula (1) can introduce two carboxyl groups into one resin per molecule. Therefore, while introducing a large amount of saturated monocarboxylic acid and dicarboxylic acid components into the resin, it is possible to introduce into the resin an amount of carboxyl groups necessary for efficiently obtaining alkali solubility with a small number of hydroxyl groups.

  Therefore, while introducing a large amount of saturated monocarboxylic acid and dicarboxylic acid components into the resin, it is possible to introduce into the resin an amount of carboxyl groups necessary for efficiently obtaining alkali solubility with a small number of hydroxyl groups. Thereby, the elongation characteristics and insulation reliability of the cured coating film by the introduction of the saturated monocarboxylic acid and the dicarboxylic acid component, and the alkali developability after preliminary drying can be compatible at a high level. In particular, a photosensitive resin composition containing a carboxyl group-containing photosensitive resin into which a compound represented by the general formula (1) is introduced while designing to the same amount of carboxylic acid is a compound other than the compound represented by the general formula (1) The alkali development can be performed in a shorter time as compared with the carboxyl group-containing photosensitive resin into which a polybasic acid or an anhydride thereof is introduced. These compounds may be used alone or in combination of two or more in order to appropriately adjust the alkali developability.

  The proportion (feed ratio) of the polybasic acid and / or polybasic acid anhydride in the carboxyl group-containing photosensitive resin (solid content) is not particularly limited, but the lower limit thereof is a point at which good alkali developability is obtained. To 7.0% by mass is preferable, and 9.0% by mass is particularly preferable. On the other hand, the upper limit thereof is preferably 20% by mass, and particularly preferably 16% by mass, from the viewpoint of reliably preventing a decrease in insulation reliability.

  The method for reacting the polybasic acid and / or the polybasic acid anhydride with the unsaturated carbon-oxidized epoxy resin which is the reaction product of the components a) to d) is not particularly limited. The reaction may be carried out by heating the polybasic acid and / or polybasic acid anhydride in a suitable diluent and adding a catalyst as required.

  The solid content acid value of the carboxyl group-containing photosensitive resin obtained by reacting a polybasic acid and / or a polybasic acid anhydride with an unsaturated carboxylated epoxy resin which is a reaction product of the components a) to d) is Although not particularly limited, it is preferably 30 to 80 mg KOH / g, particularly preferably 40 to 70 mg KOH / g, from the viewpoint of the balance between good alkali developability and prevention of reduction in insulation reliability.

  The mass average molecular weight of the carboxyl group-containing photosensitive resin is not particularly limited, but the lower limit thereof is preferably 3,000, and particularly preferably 5,000, from the viewpoint of preventing a decrease in the toughness and the touch dryness of the cured product. On the other hand, the upper limit thereof is preferably 50,000, and particularly preferably 30,000, from the viewpoint of preventing a decrease in alkali developability.

(B) Photopolymerization initiator The photopolymerization initiator is not particularly limited as long as it is generally used, and, for example, 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, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -Butanone-1, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-phenyl benzophenone, 4,4'-diethylamino benzophenone, dichloro benzophenone, 2-methyl anthraquinone, 2-ethyl anthraquinone, 2-tert-butyl anthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, P -Dimethylaminobenzoic acid ethyl ester, 2,4,6-trimethyl benzoyl diphenyl phosphine oxide, bis (2,4,6- trimethyl benzoyl) phenyl phosphite Oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentyl phosphine oxide, (2,4,6-trimethylbenzoyl) ethoxyphenyl phosphine oxide, 1,2-octanedione, 1- [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-carbazol-3-yl]-, 1- (O-acetyloxime) and the like. These may be used alone or in combination of two or more.

  The photosensitive resin composition of the present invention has excellent transparency, so that the content of the photopolymerization initiator can be reduced as compared with the prior art, and as a result, the generation of gas from the photopolymerization initiator at the time of photocuring is prevented. An excellent coating film appearance can be obtained.

  Although content of a photoinitiator is not specifically limited, 5-30 mass parts is preferable with respect to 100 mass parts of (A) carboxyl group-containing photosensitive resin, and 10-25 mass parts is especially preferable.

(C) (Meth) Acrylate Monomer (Meth) Acrylate Monomer is a photopolymerizable monomer, and by photocuring by irradiation of active energy rays such as ultraviolet rays, sufficient photocuring of the photosensitive resin composition is achieved. It is used to obtain a cured product having acid resistance, heat resistance, alkali resistance and the like. Thus, the (meth) acrylate monomer functions as a reactive diluent.

  Examples of (meth) acrylate monomers include 2-hydroxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, diethylene glycol mono (meth) acrylate, triethylene glycol di (meth) acrylate, 2-hydroxy-3. -Phenoxypropyl (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, neo Pentyl glycol adipate di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) Acrylate, ethylene oxide modified phosphoric acid di (meth) acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol Tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, propionic acid modified dipentaerythritol penta (meth) acrylate, dipentaerythritol Hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) acrylate, urethane (meth) acrylate Rate monomer. These may be used alone or in combination of two or more.

  Although content of a (meth) acrylate monomer is not specifically limited, 5-30 mass parts is preferable with respect to 100 mass parts of (A) carboxyl group-containing photosensitive resin, and 10-25 mass parts is especially preferable.

(D) Epoxy Compound The epoxy compound is for increasing the crosslink density of the cured product to obtain a cured product such as a cured coating film having sufficient mechanical strength. The epoxy compound includes, for example, an epoxy resin. As an epoxy resin, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin (eg, biphenyl novolac type epoxy resin, phenol novolac type epoxy resin, o-cresol novolac type epoxy resin, p-tert- Butylphenol novolac type etc., bisphenol F type and bisphenol S type epoxy resin obtained by reacting epichlorohydrin with bisphenol F and bisphenol S, and further an alicyclic type having cyclohexene oxide group, tricyclodecane oxide group, cyclopentene oxide group etc. Having a triazine ring such as epoxy resin, tris (2,3-epoxypropyl) isocyanurate, triglycidyl tris (2-hydroxyethyl) isocyanurate Liglycidyl isocyanurate, dicyclopentadiene type epoxy resin, adamantane type epoxy resin, phenol aralkyl type epoxy resin, phenol modified xylene resin type epoxy resin, glycidyl ester type epoxy resin (eg, diglycidyl phthalic acid ester, hexahydrophthalic acid di) Glycidyl ester, isophthalic acid diglycidyl ester, dimer acid diglycidyl ester, etc. can be mentioned. These compounds may be used alone or in combination of two or more.

  Although the compounding quantity of an epoxy compound is not specifically limited, 10-150 mass parts is preferable with respect to 100 mass parts of (A) carboxyl group-containing photosensitive resin, and 20-100 mass parts is especially preferable.

  Moreover, you may mix | blend a coloring agent, a non-reactive diluent, an additive, an antifoamer etc. suitably other than said (A)-(D) component as needed.

  The colorant is not particularly limited, such as pigments and dyes, and any of white colorants, blue colorants, yellow colorants, black colorants and the like can be used. Examples of the colorant include inorganic colorants such as titanium oxide which is a white colorant and carbon black which is a black colorant, and organic colorants such as phthalocyanine-based such as phthalocyanine green and phthalocyanine blue and anthraquinone-based. Can be mentioned.

  The nonreactive diluent is for adjusting the viscosity and the drying property of the photosensitive resin composition. As a non-reactive diluent, for example, an organic solvent can be mentioned. Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexane, aromatic hydrocarbons such as toluene and xylene, alcohols such as methanol, isopropanol and cyclohexanol, and alicyclic hydrocarbons such as cyclohexane and methyl cyclohexane. Petroleum ether, petroleum solvents such as petroleum naphtha, cellosolves such as cellosolve and butyl cellosolve, carbitols such as carbitol and butyl carbitol, ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol Esters, such as acetate and diethylene glycol monoethyl ether acetate, etc. can be mentioned.

  Additives include, for example, dicyandiamide (DICY) and derivatives thereof, curing catalysts such as melamine and derivatives thereof, coupling agents such as silanes, titanates and aluminas, acetylacetonates such as acetylacenate Zn and acetylacenate Cr Metal salts of enamines, tin octylate, quaternary sulfonium salts, imidazoles such as triphenylphosphine and 2-mercaptobenzimidazole, imidazolium salts, thermosetting accelerators such as triethanolamine borate, polycarboxylic acid amides, etc. And the like. Moreover, as an antifoamer, silicone type, hydrocarbon type, an acryl type etc. can be mentioned, for example.

  The method for producing the photosensitive resin composition of the present invention described above is not limited to a specific method, but, for example, it may be produced by mixing and dispersing the above-mentioned respective components in predetermined proportions with three rolls at room temperature. it can. Moreover, you may pre-mix with a stirrer before the said mixing dispersion | distribution as needed.

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

  Screen printing, bar coater, spray coating, applicator, blade coater, knife coater, roll coater, etc. The photosensitive resin composition manufactured as described above is printed on a flexible wiring board having a circuit pattern formed by etching a copper foil. The desired thickness is applied using a known method such as a gravure coater. After application, 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 volatilize the solvent from the photosensitive resin composition To make the surface of the coating tack free. A negative film having a light-transmissive pattern except the lands of the circuit pattern is adhered onto the applied photosensitive resin composition, and ultraviolet light (for example, in the range of wavelength 300 to 400 nm) is irradiated thereon. Then, the coating film is developed by removing the non-exposed area corresponding to the land with a dilute alkaline aqueous solution. A spray method, a shower method, etc. are used for the image development method, and 0.5-5 mass% sodium carbonate aqueous solution is mentioned as a dilute alkali aqueous solution used, for example. Subsequently, the target solder resist film can be formed on the flexible wiring board by performing post curing for 20 to 80 minutes with a hot air circulating dryer at 130 to 170 ° C. or the like.

  Next, an example of a method of forming a solder resist film using a dry film obtained by coating the photosensitive resin composition of the present invention on a flexible wiring board having a circuit pattern formed by etching a copper foil is described. Do.

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

  The electronic circuit unit is formed by soldering the electronic component on the flexible wiring board covered with the cured coating film obtained in this manner by a jet soldering method, a reflow soldering method, or the like.

  EXAMPLES Next, examples of the present invention will be described, but the present invention is not limited to these examples as long as the purpose of the present invention is not exceeded.

Photosensitive resin A-1
106.1 g of NC-3000 (epoxy group: 0.383 mol, Nippon Kayaku Co., Ltd.) in a 300 ml four-neck separable flask equipped with a stirring blade, a thermometer, a reflux tube and a nitrogen introduction tube, dodecanoic acid 24. 6 g (carboxylic acid: 0.123 mol, Kishida Chemical Co., Ltd.), adipic acid 8.4 g (carboxylic acid: 0.115 mol, Kishida Chemical Co., Ltd.), 66.1 g of diethylene glycol monoethyl ether acetate (Sanyo Chemical Co., Ltd.) In addition, the mixture was stirred at 110 ° C. for 30 minutes under a nitrogen / oxygen mixed gas atmosphere, mixed and dissolved. Then, after raising the liquid temperature of the reaction liquid to 115 ° C., 0.3 g of 4-methoxyphenol (Kishida Chemical Co., Ltd.), 10.4 g of acrylic acid (carboxylic acid: 0.145 mol, Osaka Organic Chemical Industry Co., Ltd. ) And triphenylphosphine 0.9 g (Kishida Chemical Co., Ltd.) were introduced. The mixture was stirred at 115 ° C. for 8 hours, and the acid value was measured to confirm that the carboxylic acid had completely disappeared. Then, 24.8 g of cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride (H-TMAn-S) (carboxylic acid anhydride: 0.125 mol, Mitsubishi Gas Chemical Co., Ltd.) in an air atmosphere, After adding 16.5 g of diethyldiglycol (Nippon Emulsifier Co., Ltd.) and stirring at 100 ° C. for 2 hours, the reaction completion is confirmed by FT-IR (infrared spectrophotometer), and the photosensitivity compounded in Example 1 258.0 g of resin A-1 was obtained. The mass average molecular weight (Mw) was 9100.

Photosensitive resin A-2
In the same manner as the photosensitive resin A-1, 106.1 g of NC-3000, 24.6 g of dodecanoic acid, 9.9 g of 1,4-cyclohexanedicarboxylic acid (carboxylic acid: 0.115 mol, Tokyo Chemical Industry Co., Ltd.), The reaction is carried out by reacting 66.2 g of diethylene glycol monoethyl ether acetate, 0.3 g of 4-methoxyphenol, 10.4 g of acrylic acid, 0.8 g of triphenylphosphine, 24.8 g of H-TMAn-S, and 16.5 g of diethyl diglycol. 258.5g of photosensitive resin A-1 mix | blended in Example 2 was obtained. Mw was 8400.

Photosensitive resin A-3
In the same manner as the photosensitive resin A-1, 106.1 g of NC-3000, 16.0 g of heptanoic acid (carboxylic acid: 0.123 mol, Kishida Chemical Co., Ltd.), 11.6 g of sebacic acid (carboxylic acid: 0.115 mol) Kishida Chemical Co., Ltd., 63.6 g of diethylene glycol monoethyl ether acetate, 0.3 g of 4-methoxyphenol, 10.4 g of acrylic acid, 0.8 g of triphenylphosphine, 23.8 g of H-TMAn-S (carboxylic acid anhydride: 0.120 mol) and 15.9 g of diethyl diglycol were reacted to obtain 248.4 g of a photosensitive resin A-3 blended in Example 3. Mw was 9700.

Photosensitive resin A-4
In the same manner as Photosensitive Resin A-1, 106.1 g of NC-3000, 19.5 g of heptanoic acid (carboxylic acid: 0.150 mol), 19.7 g of 8-ethyloctadecanedioic acid (carboxylic acid: 0.115 mol, Okamura Oil Co., Ltd., 69.1 g of diethylene glycol monoethyl ether acetate, 0.2 g of 4-methoxyphenol, 10.4 g of acrylic acid, 0.7 g of triphenylphosphine, 27.1 g of H-TMAn-S (carboxylic acid anhydride: 0) .137 mol) and 17.3 g of diethyl diglycol were reacted to obtain 270.1 g of the photosensitive resin A-4 blended in Example 4. Mw was 10000.

Photosensitive resin A-5
In the same manner as the photosensitive resin A-1, 104.7 g (epoxy group: 0.378 mol) of NC-3000, 32.7 g of behenic acid (carboxylic acid: 0.096 mol, NOF Corporation), stearic acid 6. 9 g (carboxylic acid: 0.024 mol, NOF Corporation), 19.5 g of 8-ethyloctadecanedioic acid (carboxylic acid: 0.114 mol, Okamura Oil Co., Ltd.), 76.8 g of diethylene glycol monoethyl ether acetate, 4-methoxy Comparative Example 1 is prepared by reacting 0.3 g of phenol, 10.2 g of acrylic acid, 0.9 g of triphenylphosphine, 28.8 g of H-TMAn-S (carboxylic anhydride: 0.145 mol), and 19.2 g of diethyl diglycol. 300.0 g of photosensitive resin A-5 to be blended in Mw was 10,500.

Photosensitive resin A-6
In the same manner as the photosensitive resin A-1, 106.1 g of NC-3000, 59.1 g of diethylene glycol monoethyl ether acetate, 0.2 g of 4-methoxyphenol, 27.6 g of acrylic acid, 0.7 g of triphenylphosphine, H 22.3 g of TMan-S (carboxylic acid anhydride: 0.113 mol) and 14.8 g of diethyl diglycol were reacted to obtain 230.7 g of a photosensitive resin A-6 blended in Comparative Example 2. Mw was 2000.

Photosensitive resin A-7
In the same manner as the photosensitive resin A-1, 106.1 g of NC-3000, 8.4 g of adipic acid, 59.1 g of diethylene glycol monoethyl ether acetate, 0.2 g of 4-methoxyphenol, 19.3 g of acrylic acid, triphenyl 0.79 g of phosphine, 22.3 g of H-TMAn-S, and 14.8 g of diethyl diglycol were reacted to obtain 230.9 g of a photosensitive resin A-7 blended in Comparative Example 3. Mw was 7000.

Photosensitive resin A-8
In the same manner as the photosensitive resin A-1, 106.1 g of NC-3000, 46.6 g of dodecanoic acid (carboxylic acid: 0.233 mol), 72.1 g of diethylene glycol monoethyl ether acetate, 0.2 g of 4-methoxyphenol, By reacting 10.8 g of acrylic acid (carboxylic acid: 0.150 mol), 0.7 g of triphenylphosphine, 27.1 g of H-TMAn-S (carboxylic anhydride: 0.137 mol), 18.0 g of diethyl diglycol, 281.5 g of photosensitive resin A-8 blended in Comparative Example 4 was obtained. Mw was 4000.

Photosensitive resin A-9
A photosensitive resin A except that 88.8 g (epoxy group: 0.383 mol, Nippon Kayaku Co., Ltd.) was used instead of NC-3000 instead of 106.1 g (epoxy group: 0.383 mol). In the same manner as -1, 240.7 g of the photosensitive resin A-9 blended in Example 5 was obtained. Mw was 10000.

Photosensitive resin A-10
A photosensitive resin A except that 91.2 g (epoxy group: 0.383 mol, Nippon Kayaku Co., Ltd.) was used instead of NC-3000 by 106.1 g (epoxy group: 0.383 mol). In the same manner as -1, 243.1 g of the photosensitive resin A-10 blended in Example 6 was obtained. Mw was 8000.

About the mass ratio of each component of photosensitive resin A-1 to A-10, it shows in following Table 1. In addition, photosensitive resin A-1 to A-10 was dried at 150 degreeC for 2 hours, and solid content of photosensitive resin A-1 to A-10 was calculated | required from mass ratio before and behind drying. The solution acid number was measured by the phenolphthalein color change method based on alkali neutralization titration. The mass average molecular weight (Mw) was measured under the following conditions using a gel permeation chromatography (GPC) apparatus (Shimadzu Corporation).
Column: TSKgel (Tosoh Corporation)
Detector: Differential Refractive Index Detector Developing solvent: Tetrahydrofuran Standard substance: Standard polystyrene Flow rate: 0.5 ml / min

Examples 1 to 6, Comparative Examples 1 to 4
Each component shown in the following Table 2 is mix | blended in the compounding ratio shown in the following Table 2, and it is made to mix and disperse at room temperature using 3 rolls, The photosensitive used in Examples 1-6 and Comparative Examples 1-4 Resin composition was prepared. In addition, the compounding quantity shown to following Table 2 represents a mass part.

Test piece preparation process The photosensitive resin composition prepared as mentioned above was coated as follows, and the test piece was produced.

Photosensitive resin composition prepared by screen printing after surface treatment of a substrate for a flexible wiring board having a circuit pattern formed on a polyimide film (Toray DuPont Co., Ltd., Kapton 100H) with diluted sulfuric acid (3 mass%) Was applied and then predried at 80 ° C. for 20 minutes in a BOX furnace. After predrying, a negative film (photomask) having a light-transmitting pattern other than the lands of the circuit pattern is brought into close contact with the coating film, and ultraviolet light is exposed onto the film from above (HMW-680GW, Oak Manufacturing Co., Ltd.) Exposure to 500 mJ / cm ² . Then, after developing with a 1% by mass sodium carbonate developing solution at 30 ° C., a cured coating is formed on the substrate by post curing at 150 ° C. for 60 minutes in a BOX furnace, and Examples and Comparative Examples Test pieces were obtained. The thickness of each cured coating was 20 to 23 μm.

Evaluation items (1) Undercut (resolution)
A line of cured coating was formed on the polyimide film using a photomask with a width of 100 μm. The line shape is observed with a metallurgical microscope (magnification: 100 times) from the cut surface of the formed line, and the width (x) on the surface side of the line and the width (y) on the bottom side (deep side) are measured. The undercut value was measured from −y) / 2 and evaluated according to the following criteria.
○: 5 μm or less Δ: more than 5 μm and 15 μm or less ×: 15 μm or more

(2) Growth rate (%)
The photosensitive resin composition prepared as described above is uniformly coated on a polyethylene terephthalate (PET) film using a bar coater so as to have a thickness of 50 μm ± 10 μm, and then the steps from the above pre-drying to post curing Conducted to form a cured coating. Then, about the sample which peeled off the cured coating film formed from the PET film and was cut into a predetermined size, the elongation rate was measured on condition of 5 mm / min of tensile velocity using an autograph by Shimadzu Corp. The following criteria were evaluated.
:: over 60% ○: over 45% 60% or less 以下: over 30% 45% or less ×: 30% or less

(3) Nose-to-touch property After the preliminary drying of the test piece preparation step, the negative film was brought into contact with the coating film, and after exposure, the adhesion of the coating film to the negative film was evaluated. Evaluation was performed on the basis of the following.
:: no adhesion △: coating remains on the film ×: negative film after peeling off, the film adheres to the negative film

  The evaluation results of Examples 1 to 6 and Comparative Examples 1 to 4 are shown in Table 2 below.

  From Table 2, an epoxy resin having two or more epoxy groups in one molecule, a saturated monocarboxylic acid having 5 to 17 carbon atoms (in the example, a saturated monocarboxylic acid having 7 or 12 carbon atoms) and a dicarboxylic acid Embedded image e) a polybasic acid and / or a polybasic acid anhydride (in the example, cyclohexane), which is a reaction product of a carboxylic acid and an ethylenically unsaturated group-containing carboxylic acid (an acrylic acid in the example); Carboxyl group-containing photosensitive resin (photosensitive resin A-1 to A-4, A-9 to A-10) obtained by adding -1,2,4-tricarboxylic acid-1,2-anhydride) In Examples 1 to 6, each of which was used, a clear resin solution was obtained, and it had excellent finger dryability. Furthermore, in Examples 1 to 6, it was possible to obtain a cured coating film having an excellent line shape in which undercuts are prevented and having excellent elongation characteristics. In particular, Examples 1 to 3, 5 and 6 in which the carbon number of the dicarboxylic acid introduced into the carboxyl group-containing photosensitive resin is 6 to 10 are further compared to Example 4 in which the carbon number is 20. An excellent line shape can be obtained, and the resolution is further improved. Further, in Example 1 using a biphenyl aralkyl type epoxy resin and Example 6 using a phenol aralkyl type epoxy resin, the elongation was further improved as compared to Example 5 using a naphthalene type epoxy resin.

  On the other hand, in Comparative Example 1 in which the saturated monocarboxylic acid having 18 carbon atoms and the saturated carboxylic acid having 22 carbon atoms were introduced into the epoxy resin and the medium-chain to long-chain dicarboxylic acid was not introduced, The transparency was lowered, and the undercut was not prevented to obtain resolution. Moreover, in Comparative Example 1, no finger dryness was also obtained. Further, Comparative Example 2 in which neither a medium chain to long chain saturated monocarboxylic acid nor a medium chain to long chain saturated carboxylic acid was introduced into the carboxyl group-containing photosensitive resin, a carboxyl group-containing photosensitive resin to medium chain to long chain saturated mono Comparative Example 3 in which a medium-chain dicarboxylic acid having 6 carbon atoms is introduced without introducing a carboxylic acid, a long-chain saturated monocarboxylic acid having 12 carbon atoms without introducing a medium-chain to long-chain dicarboxylic acid into a carboxyl group-containing photosensitive resin In Comparative Example 4 in which the acid was introduced, the elongation characteristics were not improved in all cases, and flexibility was not obtained.

  The photosensitive resin composition of the present invention has an excellent line shape in which undercut is prevented without impairing basic properties such as touch dryness, and a cured coating film excellent in elongation properties can be obtained. Therefore, for example, it has high utility value in the field of protective films of printed wiring boards (eg, flexible wiring boards, rigid wiring boards, etc.) on which electronic components are mounted at high density.

Claims (10)

  (A) a) an epoxy resin having two or more epoxy groups in one molecule, b) at least one saturated monocarboxylic acid having 5 to 17 carbon atoms, c) dicarboxylic acid and d) ethylenic unsaturation A carboxyl group-containing photosensitive resin obtained by adding e) a polybasic acid and / or a polybasic acid anhydride to an unsaturated carboxylic acid epoxy resin which is a reaction product with a group-containing carboxylic acid, and (B) A photosensitive resin composition comprising: a photopolymerization initiator.   The photosensitive resin composition according to claim 1, wherein the b) at least one saturated monocarboxylic acid having 5 to 17 carbon atoms is linear.   The photosensitive resin composition according to claim 1 or 2, wherein the c) dicarboxylic acid comprises at least one dicarboxylic acid having 6 to 20 carbon atoms.   The photosensitive resin composition according to claim 1 or 2, wherein the c) dicarboxylic acid contains at least one dicarboxylic acid having 6 to 10 carbon atoms. The above e) polybasic acid and / or polybasic acid anhydride is a polybasic acid anhydride, and the polybasic acid anhydride is represented by the following general formula (1)
(Wherein, 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 a compound represented by these, The photosensitive resin composition of any one of the Claims 1 thru | or 4 characterized by the above-mentioned.   Furthermore, (C) (meth) acrylate monomer is included, The photosensitive resin composition of any one of the Claims 1 thru | or 5 characterized by the above-mentioned.   Furthermore, the photosensitive resin composition according to any one of claims 1 to 6, further comprising (D) an epoxy compound.   A dry film characterized in that the photosensitive resin composition according to any one of claims 1 to 7 is coated on a film.   A printed wiring board having a photocured film obtained by patterning a coating film formed by laminating the dry film according to claim 8 on a substrate.   A printed wiring board having a photocured film obtained by patterning a coating film formed by applying the photosensitive resin composition according to any one of claims 1 to 7 on a substrate.