JP2010077283A - Multibranched polyester(meth)acrylate compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive thermocurable resin composition for solder resist with balanced functionality and coating capacity suitable for flexible printed circuit board, and to provide a compound which can give the cured product of the same. <P>SOLUTION: The multibranched polyester (meth)acrylate compound (A) is prepared by reacting a multibranched polyester polyol (a), a monoisocyanate containing a unsaturated group (b), and a polybasic anhydride (c). Also in one preferable embodiment of the compound, the reaction product of the multibranched polyester polyol (a) and the monoisocyanate containing a unsaturated group (b) is reacted with the polybasic anhydride (c). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hyperbranched polyester (meth) acrylate compound, a photosensitive thermosetting resin composition, and a cured product obtained by curing a photosensitive thermosetting resin composition.

  The solder resist ink is used for protecting a circuit when a printed wiring board is produced. In terms of the function of the ink, ultraviolet curing property, developability, and the cured coating film are required to have long-term electrical insulation in addition to performance such as solder heat resistance and plating resistance. Substrate types can be broadly classified into rigid and flexible types. Rigid type substrates have a long history and are mainly used for electrical appliances that can secure the board area. Flexible type substrates are used for small electrical appliances with little space, such as digital cameras and mobile phones. All the substrates are progressing toward higher density and higher accuracy, and the demands for the materials used are becoming stricter.

  In the production of the current flexible printed circuit board, a method for forming an insulating film protective layer includes a method in which a film obtained by punching a circuit pattern with a mold is bonded with an adhesive, and a method in which a film is formed with a photosensitive thermosetting resin composition. There is. The former is excellent in flexibility and folding resistance, but has a problem that a die is required for each pattern and that it cannot cope with a fine pattern. On the other hand, the latter can deal with fine patterns, but the film warps and changes its shape, the adhesiveness is insufficient and peeling occurs, or the folding resistance is insufficient and cracks occur when bent. Have

  Various studies have been made on these problems. For example, a resist ink containing a soft polycarboxylic acid acrylic resin and an epoxy resin as essential components is known (Patent Document 1). In addition, resist inks in which the double bond equivalent of a polyfunctional epoxy acrylate resin is adjusted and resist inks containing rubber-modified epoxy acrylate as an essential component are known (Patent Documents 2 and 3). In recent years, demands for high density and high accuracy have been increasing even for flexible type substrates. When forming an insulating film protective layer, a method in which a film obtained by punching a circuit pattern with a mold is pasted with an adhesive or a conventional method for applying a photosensitive thermosetting resin composition for a solder resist is known.

JP-A-11-15825 JP2007-224169A JP 11-265066 A

  However, the resist ink containing the soft polycarboxylic acid acrylic resin and the epoxy resin as essential components has low heat resistance although it solves the problems of flexibility and warping, and cannot be applied to high-density mounting in recent years. The problem remains. In addition, the resist ink and the like containing the above-described rubber-modified epoxy acrylate as an essential component solves the problems of flexibility and warpage and has excellent folding resistance, but tackiness and developability during solvent drying, There is a problem that the sensitivity is not sufficient. Thus, as a solder resist, coating such as sensitivity, tackiness in solvent drying, developability, etc. and flexibility, folding resistance, plating resistance, electrical insulation required for flexible printed circuit boards It is difficult to satisfy the performance in a well-balanced manner, and there is no photosensitive thermosetting resin composition for solder resists that has been sufficiently satisfied so far.

  In addition, the method of pasting a film having a circuit pattern punched out with an adhesive with an adhesive does not correspond to high density and high accuracy, and is a method of applying the conventional photosensitive thermosetting resin composition for solder resist However, the balance between functionality such as developability and coating performance such as folding resistance, adhesion, and flexibility is not sufficient.

  Accordingly, in order to solve the above problems, an object of the present invention is to provide a photosensitive thermosetting resin composition for a solder resist having a good balance between functionality and coating film performance suitable for a flexible printed wiring board and a cured product thereof. There is to do.

  In order to achieve the above object, the present inventors have intensively studied to solve the above problems, and as a result, a photocurable resin composed of a novel multi-branched polyester (meth) acrylate, an epoxy compound, a photopolymerization initiator, It has been found that a composition containing a diluted good as an essential component is excellent in ultraviolet curability, developability, solder heat resistance, plating resistance, electrical insulation and the like, and has little warpage during curing and excellent folding resistance. The present invention has been completed.

  That is, the multibranched polyester (meth) acrylate compound (A) of the present invention is obtained by reacting a multibranched polyester polyol (a), an unsaturated group-containing monoisocyanate (b), and a polybasic acid anhydride (c). It is characterized by that.

  Further, in a preferred embodiment of the compound of the present invention, it is obtained by reacting a polybasic acid anhydride (c) with a reaction product of a multi-branched polyester polyol (a) and an unsaturated group-containing monoisocyanate (b). Features.

  In a preferred embodiment of the compound of the present invention, the multi-branched polyester polyol (a) is synthesized from an alcohol having two or more hydroxyl groups and a polycarboxylic acid.

  In a preferred embodiment of the compound of the present invention, the multi-branched polyester polyol (a) is characterized in that an alcohol having 3 or more hydroxyl groups is an essential component.

  In a preferred embodiment of the compound of the present invention, the multibranched polyester polyol (a) is characterized in that the average number of hydroxyl groups per molecule (number average molecular weight / hydroxyl group equivalent) is 8 to 32.

  In a preferred embodiment of the compound of the present invention, the polyfunctional polyester (meth) acrylate compound (A) has a carboxyl group in the range of 50 to 110 mgKOH / g.

  In a preferred embodiment of the compound of the present invention, the polyfunctional polyester (meth) acrylate compound (A) has a (meth) acryloyl group equivalent in the range of 600 to 1200 g / eq.

  The photosensitive thermosetting resin composition of the compound of the present invention comprises the multi-branched polyester (meth) acrylate compound (A), an epoxy compound (B) having two or more epoxy groups in one molecule, and a photopolymerization initiator. It contains (C) and diluent (D) as essential components.

  The cured product of the present invention is obtained by curing the photosensitive thermosetting resin composition according to claim 8.

  The photo-curable compound of the present invention, that is, a multi-branched polyester (meth) acrylate compound obtained by reacting a multi-branched polyester polyol, an unsaturated group-containing monoisocyanate, and a polybasic acid anhydride has excellent heat resistance and flexibility. It has an advantageous effect of being excellent and having excellent folding resistance. In addition, the photosensitive thermosetting resin composition of the present invention containing such a photocurable compound of the present invention as a photocurable component has an excellent balance of touch drying property, photocurability, and alkali developability, In addition to providing a cured product with a high level of sufficient flexibility, heat resistance, adhesion and PCT resistance, and no warping after thermosetting, printed wiring board production and printed wiring with solder resist applied Manufacture of IC packages such as BGA (Ball Grid Array) and CSP (Chip Scale Package) using boards and sealing resin, especially for COF (Chip on Film) and / or flexible printed circuit boards There is an advantageous effect of facilitating the mounting of electronic components.

  The photosensitive thermosetting resin composition of the present invention and / or its cured product is advantageous in that it is excellent in ultraviolet curability, developability with an aqueous alkali solution, chemical resistance, electrical insulation, adhesion, and folding resistance. There is an effect.

  An example of the present invention will be described in detail below. First, in this specification, (meth) acrylate means a methacrylate compound, an acrylate compound, or a mixture thereof, and (meth) acrylic acid ester means a methacrylic acid ester, an acrylic acid ester, or a mixture thereof.

  First, a hyperbranched polyester (meth) acrylate compound (A) obtained by reacting a hyperbranched polyester polyol (a), an unsaturated group-containing monoisocyanate (b), and a polybasic acid anhydride (c), and the hyperbranched polyester The multibranched polyester (meth) acrylate compound (A) obtained by reacting the polybasic acid anhydride (c) with the reaction product of the polyol (a) and the unsaturated group-containing monoisocyanate (b) will be described.

  In the present invention, the hyperbranched polyester polyol (a), the unsaturated group-containing monoisocyanate (b), and the polybasic acid anhydride (c) may be reacted. A polybasic acid anhydride (c) may be reacted with the reaction product of isocyanate (b). From the viewpoint of stabilizing alkali developability when the compound of the present invention is used as a composition, a multibranched polyester is used. It is preferable to further react the polybasic acid anhydride (c) with the reaction product of the polyol (a) and the unsaturated group-containing monoisocyanate (b).

  In the present invention, the alcohol component constituting the multi-branched polyester polyol (a) is not particularly limited, but if the alcohol compound having three or more hydroxyl groups is not contained, there is no branch of the polyester polyol, From the viewpoint that the number of hydroxyl groups is small and a multi-branched polyester (meth) acrylate compound (A) that satisfies the required performance may not be synthesized, it is preferable to use a compound having three or more hydroxyl groups. For example, glycerin and / or trimethylolpropane is preferably used as the alcohol having three or more hydroxyl groups. Examples of other alcohol components include neopentyl glycol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1,5-pentanediol, 1,6-hexanediol, 3,3-dimethylolheptane, 1,4-cyclohexanedimethanol, spiroglycol, bisphenol A ethylene oxide adduct Bisphenol A propylene oxide adduct, trimethylolethane, pentaerythritol, dipentaerythritol and the like can be used, and can be used in combination with the above-described alcohol component.

  The polycarboxylic acid component constituting the multi-branched polyester polyol (a) of the present invention is not particularly limited, but isophthalic acid and / or terephthalic acid is preferably used. Bifunctional or higher acid or polybasic acid anhydrides can be used as long as the properties of the multibranched polyester (meth) acrylate compound (A) of the present invention are not impaired. For example, phthalic anhydride, biphenyldicarboxylic acid , Naphthalenedicarboxylic acid, tetrahydrophthalic acid, adipic acid, azelaic acid, sebacic acid, fumaric acid, cyclohexanedicarboxylic acid, dimer acid and the like. Further, a tri- or tetrafunctional acid component such as trimellitic anhydride, trimesic acid, pyromellitic anhydride may be used in combination as long as the multi-branched polyester polyol (a) is not gelled.

  The multi-branched polyester polyol (a) as a raw material of the multi-branched polyester (meth) acrylate compound (A) of the present invention is produced by a known production method using the above-mentioned predetermined alcohol component and acidic component as raw materials. Can do. During the reaction, the temperature in the kettle is not particularly limited, but is preferably 195 to 250 ° C. If the temperature is lower than 195 ° C., the number of branches may decrease and the degree of dispersion may decrease, and the tack-free property and chemical resistance at the time of solvent drying required for the multi-branched polyester (meth) acrylate compound (A) cannot be satisfied. On the other hand, if the temperature exceeds 250 ° C., the alcohol is easily discharged out of the system, and the balance between the alcohol and the acid is lost, so that the target multi-branched polyester polyol (a) may not be obtained. The end point of the reaction is preferably 8 mg KOH / g or less in terms of acid value. When the reaction is terminated before reaching 8 mg KOH / g or less, a reaction other than the target reaction occurs in the subsequent reaction, and the desired product having the desired characteristics is obtained. There is a possibility that it cannot be obtained. In addition, a well-known reaction catalyst can be used for the synthesis | combination of multibranched polyester polyol (a).

  The average number of hydroxyl groups (number average molecular weight / number of hydroxyl groups) per molecule of the multi-branched polyester polyol (a) obtained by the above-described raw materials and production method is not particularly limited, but 8 to 32 is the number. preferable. When the polyfunctional polyester (meth) acrylate compound (A) is used with less than 8 compounds (a), the sensitivity to light may be deteriorated. On the other hand, when the number exceeds 32, the polyfunctional polyester (meth) acrylate is used. Since many hydroxyl groups remain in the compound (A) and the molecular weight increases, there is a possibility of adversely affecting the developability and moisture resistance and chemical resistance, which are coating film performance.

  The unsaturated group-containing monoisocyanate (b) used in the present invention is a monoisocyanate having an ethylenically unsaturated group, such as 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate, isophorone diisocyanate and 2-hydroxy. And an equimolar reaction product of an unsaturated group-containing monoalcohol such as ethyl (meth) acrylate. These can be used alone or in combination.

  The reaction between the multi-branched polyester polyol (a) and the unsaturated group-containing monoisocyanate (b) can be carried out in the same manner as the known urethane acrylate synthesis method under air flow, and no catalyst or an appropriate amount of catalyst can be added. good. The reaction between the multi-branched polyester polyol (a) and the unsaturated group-containing monoisocyanate (b) can be followed by IR until the isocyanate peak in the vicinity of 2380 cm −1 disappears. In order to ensure the stability during production and the storage stability of the reaction product, it is preferable to use a known polymerization inhibitor. Examples of such a polymerization inhibitor include hydroquinone, monomethyl ether hydroquinone, toluhydroquinone, di-tert-4-methylphenol, trimonomethyl ether hydroquinone, phenothiazine, and tert-butylcatechol. The amount of these used is in the range of 0.0001 to 1 part by weight, preferably 0.001 with respect to 100 parts by weight in total of the reaction of the hyperbranched polyester polyol (a) and the unsaturated group-containing monoisocyanate (b). It can be used in the range of ~ 0.2 parts by weight. If the amount is less than 0.0001 parts by weight, the polymerization inhibition effect is small, gelation occurs during the reaction, and the target compound may not be obtained or the storage stability of the reaction product may be significantly reduced. It is not preferable. On the other hand, when the amount exceeds 1 part by weight, the curing reaction of the photosensitive thermosetting resin composition is inhibited, and a cured product containing an uncured product is obtained, which may not satisfy the required performance of each characteristic.

  The (meth) acryloyl group equivalent of the polyfunctional polyester (meth) acrylate compound (A) of the present invention is not particularly limited, but is preferably in the range of 600 to 1200 g / eq. If the (meth) acryloyl group equivalent is less than 600 g / eq, it is not preferred because the shrinkage during curing is large and warping may occur and the film may be deformed. If it exceeds 1200 g / eq, the photocurability is lowered and an image pattern can be drawn. There is a risk that the chemical resistance will be lost.

  Moreover, the multibranched polyester (meth) acrylate compound (A) of the present invention may be reacted with a multibranched polyester polyol (a), an unsaturated group-containing monoisocyanate (b), and a polybasic acid anhydride (c). Further, the polybasic acid anhydride (c) may be reacted with the reaction product of the multi-branched polyester polyol (a) and the unsaturated group-containing monoisocyanate (b).

  The polybasic acid anhydride (c) is not particularly limited, and examples thereof include maleic anhydride, succinic anhydride, itaconic anhydride, octenyl succinic anhydride, pentadodecenyl succinic anhydride, phthalic anhydride, tetrahydro Dibasic acid anhydrides such as phthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, nadic anhydride, 3,6-endomethylenetetrahydrophthalic anhydride, tetrabromophthalic anhydride, anhydrous Tribasic acid anhydrides such as trimellitic acid, pyromellitic anhydride, biphenyl tetracarboxylic dianhydride, diphenyl ether tetracarboxylic dianhydride, butane tetracarboxylic dianhydride, benzophenone tetracarboxylic dianhydride, diphenyl sulfone Tetracarboxylic dianhydride, Glycol - bis (trimellitic acid) ester, glycerol alpha, alpha-bis (trimellitic anhydride) ester β- monoacetate, tetracarboxylic acid anhydrides such as naphthalene tetracarboxylic acid dianhydride.

  Among these, aliphatic or alicyclic structures such as succinic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, etc. from the viewpoint of ink stability and developability. It is preferred to select a polybasic acid anhydride having. Moreover, the said polybasic acid anhydride (c) can be used individually or in combination of 2 or more types.

  The acid value of the polyfunctional polyester (meth) acrylate compound (A) of the present invention is not particularly limited, but is preferably in the range of 50 to 110 mgKOH / g from the viewpoint of ink stability and developability. When the acid value is less than 50 mgKOH / g, the solubility in an alkaline aqueous solution is deteriorated, and development of the formed cured film may be difficult, and solder heat resistance and PCT resistance may be reduced. On the other hand, if it exceeds 110 mgKOH / g, the polyfunctional polyester (meth) acrylate compound (A) is developed up to the surface of the exposed part regardless of the exposure conditions in photocuring (temporary curing), or the PCT resistance is greatly reduced. There is a risk that.

  Next, it contains a polyfunctional polyester (meth) acrylate compound (A), an epoxy compound (B) having two or more epoxy groups in one molecule, a photopolymerization initiator (C), and a diluent (D). The photosensitive thermosetting resin composition will be described.

  The epoxy compound (B) having two or more epoxy groups in one molecule constituting the photosensitive thermosetting resin composition is not particularly limited, but phenols having two or more active hydrogens in one molecule. Carboxylic acids, glycols, or amines can be obtained by epoxidizing with epichlorohydrin by a known method, alone or in combination of two or more. Also, phenols, carboxylic acids, glycols, or amines having two active hydrogens in one molecule are epoxidized with epichlorohydrin by a known method, alone or in combination of two or more, and further in the molecule An epoxy compound having three or more epoxy groups in one molecule obtained by epoxidizing a secondary alcoholic hydroxyl group with epichlorohydrin by a known method can also be used. Furthermore, it is obtained by epoxidizing phenol novolaks having 3 or more phenolic hydroxyl groups in one molecule obtained by addition condensation of phenols such as phenol and cresol with formaldehyde by a known method. Epoxy compounds having 3 or more epoxy groups in one molecule can also be used.

  A general commercial item can also be used for the epoxy compound (B) which has a 2 or more epoxy group in 1 molecule. Examples of commercially available products include “Epicoat 828”, “Epicoat 834”, “Epicoat 1001” and “Epicoat 1004” manufactured by Japan Epoxy Resin Co., Ltd., and “Epicron 840” manufactured by Dainippon Ink and Chemicals, Inc. “Epicron 850”, “Epicron 1050”, “Epicron 2055”, trade names “Epototo 128” manufactured by Tohto Kasei Co., Ltd., trade names “D.E.R. 317”, “D.E.R. .331 ”,“ D.E.R.661 ”,“ D.E.R.664 ”, trade names“ Araldite 250 ”,“ Araldite 260 ”,“ Araldite 2600 ”manufactured by Asahi Kasei Kogyo Co., Ltd., Sumitomo Chemical Co., Ltd. Bisphenols such as “Sumiepoxy ESA-011”, “Sumiepoxy ESA-014”, “Sumiepoxy ELA-128” Type A epoxy compound, trade name “Epicron 830S” manufactured by Dainippon Ink & Chemicals, Inc., product name “Epicoat 807” manufactured by Japan Epoxy Resin Co., Ltd., trade names “Epototo YDF-170”, “Epototo YDF-” manufactured by Tohto Kasei Co., Ltd. 175 ”,“ Epototo YDF-2004 ”,“ Araldite XPY306 ”manufactured by Asahi Kasei Kogyo Co., Ltd., Nippon Kayaku product name“ EBPS-200 ”, Asahi Denka Kogyo product name“ EPX ” -30 ", bisphenol S-type epoxy compounds such as Dainippon Ink & Chemicals' brand name" Epicron EXA1514 ", bisphenol fluorene-type epoxy compounds such as Osaka Gas's brand name" BPFG ", Japan Epoxy Resin Product names “YL-6056”, “YL-6021”, “YX-4” 00 ”,“ YX-4000H ”and other bixylenol type or biphenyl type epoxy compounds, or mixtures thereof, trade names“ Epototo ST-2004 ”,“ ST-2007 ”,“ ST-3000 ”manufactured by Tohto Kasei Co., Ltd. Hydrogenated bisphenol A type epoxy compounds such as “Epicoat 152” and “Epicoat 154” manufactured by Japan Epoxy Resin Co., Ltd., and “D.E.N. 431” and “D.E. N.438 ”, trade names“ Epicron N-690 ”,“ Epicron N-695 ”,“ Epicron N-730 ”,“ Epicron N-770 ”,“ Epicron N-865 ”, manufactured by Dainippon Ink & Chemicals, Product names “Epototo YDCN-701”, “Epototo YDCN-704” manufactured by Toto Kasei Co., Ltd., “Araldite” manufactured by Asahi Kasei Kogyo Co., Ltd. “ECN1235”, “Araldite ECN1273”, “Araldite ECN1299”, “Araldite XPY307”, trade names “EPPN-201”, “EOCN-1025”, “EOCN-1020”, “EOCN-104S” manufactured by Nippon Kayaku Co., Ltd. “RE-306”, trade names “Sumiepoxy ESCN-195X” and “ESCN-220” manufactured by Sumitomo Chemical Co., Ltd., trade name “Epicoat YL-903” manufactured by Japan Epoxy Resin, Dainippon Trade names “Epicron 152” and “Epicron 165” manufactured by Ink Chemical Industries, Ltd., “Epototo YDB-400” and “Epototo YDB-500” manufactured by Tohto Kasei Co., Ltd., and “D. E. R542 ”, trade name“ Araldite 8018 ”manufactured by Asahi Kasei Kogyo Co., Ltd., brominated bisphenol A type epoxy compounds such as“ Sumiepoxy ESB-400 ”and“ Sumiepoxy ESB-700 ”manufactured by Sumitomo Chemical Co., Ltd., manufactured by Nippon Steel Chemical Co., Ltd. Epoxy compounds having a naphthalene skeleton such as “ESN-190”, “ESN-360”, and trade names “HP-4032”, “EXA-4700”, “EXA-4750” manufactured by Dainippon Ink and Chemicals, Inc. Epoxy compounds having a dicyclopentadiene skeleton such as trade names “HP-7200” and “HP-7200H” manufactured by Dainippon Ink & Chemicals, Inc., trade names “YL-933” manufactured by Japan Epoxy Resin, Nippon Kayaku Trishydroxyphenylmethane type epoxy such as “EPPN-501” and “EPPN-502” Compound, product name “TEPIC” manufactured by Nissan Chemical Co., Ltd., heterocyclic epoxy compound such as product name “TGI” manufactured by Mitsubishi Gas Chemical Company, product name “Epicoat 604” manufactured by Japan Epoxy Resin Co., Ltd. Glycidylamine-type epoxy compounds such as “Epototo YH-434”, Asahi Kasei Kogyo Co., Ltd. “Araldite MY720”, Sumitomo Chemical Co., Ltd. “Sumiepoxy ELM-120”, Daicel Chemical Industries, Ltd. Examples include alicyclic epoxy compounds such as the name “Celoxide 2011”, trade names “Araldite CY175”, “Araldite CY179” manufactured by Asahi Kasei Kogyo Co., Ltd., and the product name “HBE-100” manufactured by Shin Nippon Chemical Co., Ltd. It is not limited to. These epoxy compounds can be used alone or in combination of two or more.

  The epoxy compound (B) having two or more epoxy groups in one molecule is formed with a carboxyl group of the polyfunctional polyester (meth) acrylate compound (A) by performing finish curing with heat after forming a resist pattern. It reacts with each other to form a strong bond, and improves the properties such as adhesion between the cured film of the solder resist and the base material, and heat resistance. Although the compounding quantity is not specifically limited, An epoxy group is 0.1-1.5 equivalent with respect to 1 equivalent of carboxyl groups in the molecule | numerator of a polyfunctional polyester (meth) acrylate compound (A), Preferably Is blended within the range of 0.5 to 1.3 equivalents. When the amount is less than 0.1 equivalent, the hygroscopic property of the cured film is increased, and the electrical insulation property may be lowered. On the other hand, when the amount exceeds 1.5 equivalents, photocurability (temporary curing) and alkali developability are lowered, and it is difficult to form an image of a resist pattern.

  Next, the photopolymerization initiator (C) in the curable resin composition of the present invention will be described in detail. The photopolymerization initiator (C) used in the present invention has a function of generating radicals by irradiation with ultraviolet rays (light) and curing by radical polymerization when the curable resin composition is photocured (temporarily cured). As such a photopolymerization initiator (C), known ones can be used. Preferred photopolymerization initiators (C) include, for example, benzoins such as benzoin, benzyl, benzoin methyl ether, and benzoin isopropyl ether. And benzoin alkyl ethers, acetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2- Atophenones such as morpholino-propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, N, N-dimethylaminoacetophenone, 2-methylanthraquinone, 2- Ethyl anthraquinone, 2-amino Anthraquinones such as anthraquinone, thioxanthones such as 2,4-dimethylthioxanthone, ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal, benzophenone, methylbenzophenone, 4,4′-dichlorobenzophenone, 4,4′-bisdiethylamino Examples include benzophenones such as benzophenone and xanthones, and these can be used alone or in combination of two or more. Further, such a photopolymerization initiator (C) is a benzoic acid ester such as ethyl-4-dimethylaminobenzoate or 2- (dimethylamino) ethylbenzoate, or a tertiary amine such as triethylamine or triethanolamine. Such known photosensitizers can be used alone or in combination of two or more.

  Although the usage-amount of the said photoinitiator (C) is not specifically limited, It uses in the range of 0.1-30 weight part with respect to 100 weight part of acid-modified epoxy (meth) acrylate compounds (A). It is preferable to use in the range of 1 to 20 parts by weight. When the amount is less than 0.1 parts by weight, the polymerization does not proceed due to ultraviolet (light) irradiation, and the formed film may be uncured and the alkali developability may be deteriorated. The heat resistance and mechanical properties of the film may be reduced.

  Next, the diluent (D) in the curable resin composition of the present invention will be described in detail.

Examples of the diluent (D) used in the curable resin composition of the present invention include an organic solvent and a (meth) acrylic ester, dissolves the polyfunctional polyester (meth) acrylate compound (A), and serves as a solder resist ink. Diluents that have the effect of ensuring an appropriate working viscosity and have reactivity such as (meth) acrylic acid esters are incorporated into the network during radical polymerization, improving photocurability, heat resistance, and crack resistance, The effect which improves the adhesiveness etc. with a board | substrate is produced.
Further, the diluent (D) includes a multi-branched polyester polyol (a) having at least 4 hydroxyl groups in one molecule and an unsaturated group-containing monoisocyanate (b) in the production of the polyfunctional polyester (meth) acrylate compound (A). ) And the reaction of adding polybasic acid anhydride (c), the diluent (D) is adjusted to an appropriate viscosity for the purpose of obtaining a stable reaction product that does not cause gelation. You can also.

  Examples of such diluent (D) include ketones such as methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene, methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, and propylene. Glycol ethers such as glycol monoethyl ether, dipropylene glycol diethyl ether, triethylene glycol monoethyl ether, esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate, carbitol acetate, ethanol, propanol, ethylene glycol, propylene glycol, etc. Of organic solvents such as alcohols, aliphatic hydrocarbons such as octane and decane, petroleum ethers such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha and solvent naphtha. It can be exemplified, but the invention is not limited thereto. These can be used alone or in combination of two or more.

  In addition, the diluent (D) can be used by replacing part or all of the organic solvent with (meth) acrylic acid esters having photocurability. Examples of such (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, i-butyl (meth) acrylate, and t-butyl. (Meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, alkyl (meth) acrylate such as stearyl (meth) acrylate, epoxy group-containing (meth) acrylate such as glycidyl (meth) acrylate, ( Aminoalkyl (meth) acrylates such as (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropy Hydroxyalkyl (meth) acrylates such as (meth) acrylate, mono- or di (meth) acrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, N, N-dimethyl (meth) acrylamides, N, N -Aminoalkyl (meth) acrylates such as dimethylaminoethyl (meth) acrylate, hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, polyhydric alcohols such as tris-hydroxyethylisosinurate, or , These ethylene oxide or propylene oxide adduct polyvalent (meth) acrylates, phenoxyethyl (meth) acrylate, bisphenol A polyethoxydi ( (E) (meth) acrylates of ethylene oxide or propylene oxide adducts of phenols such as acrylate, glycidyl ether (meth) acrylates such as glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl isocyanurate, ε -Ε-caprolactone-modified (meth) acrylates such as caprolactone-modified tris (acryloxyethyl) isocyanurate, melamine (meth) acrylate, and the like can be mentioned, but are not limited thereto. These can be used alone or in combination of two or more.

  Although the usage-amount of the said diluent (D) is not specifically limited, Preferably, it mix | blends in the range of 1-300 weight part with respect to 100 weight part of acid-modified epoxy (meth) acrylate compounds (A). Moreover, when using (meth) acrylic acid ester as said diluent (D), the usage-amount is 3-50 with respect to 100 weight part of said acid-modified epoxy (meth) acrylate compounds (A). It is preferable to use in the range of parts by weight, preferably in the range of 5 to 15 parts by weight. If the amount is less than 3 parts by weight, the effect of imparting photocurability is not sufficient, and if it exceeds 50 parts by weight, the dryness to touch of the dry film is lowered, which is not preferable.

  The curable resin composition of the present invention has a carboxyl group in the molecule of the multi-branched polyester (meth) acrylate compound in the thermosetting step (finish curing) and two or more epoxy groups in one molecule as necessary. For the purpose of promoting the reaction with the epoxy compound (B) it has, a curing accelerator can be added. Examples of the curing accelerator include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1- Imidazole derivatives such as (2-cyanoethyl) -2-ethyl-4-methylimidazole, guanamines such as guanamine, acetoguanamine, benzoguanamine, dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine And amine compounds such as 4-methyl-N, N-dimethylbenzylamine and melamine. These can be used alone or in combination of two or more.

  The amount of such a curing accelerator used is not particularly limited, but in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the multi-branched polyester (meth) acrylate compound (A), Preferably it can be used in the range of 0.5 to 2 parts by weight. When the amount is less than 0.1 part by weight, the effect of promoting the curing reaction of the epoxy compound (B) having two or more epoxy groups in one molecule may be reduced, and when the amount exceeds 10 parts by weight The life of the curable resin composition may be shortened.

  An inorganic filler can be added to the curable resin composition of the present invention for the purpose of improving the adhesion to the printed wiring board, if necessary. For example, inorganic fillers such as talc, silica, barium sulfate, barium titanate, silicon oxide, aluminum oxide, calcium carbonate, and aluminum hydroxide can be blended. These inorganic fillers can be added in a range of up to 150 parts by weight with respect to 100 parts by weight of the curable resin composition. If it exceeds 150 parts by weight, the curability may be adversely affected and the physical properties of the cured film may be reduced. In addition to the above components, the curable resin composition of the present invention may contain various colorants, leveling agents, antifoaming agents, and the like that are added to ordinary solder resist resin compositions as necessary. it can.

  The curable resin composition of the present invention is obtained by uniformly mixing the above-described blending components (A), (B), (C) and (D), and blending components added as necessary, using a roll mill, a sand mill or the like. Can be obtained by mixing. Moreover, application | coating on the printed wiring board of the curable resin composition of this invention is normally performed by the screen printing method, the electrostatic coating method, the roll coater method, the curtain coater method, etc. After coating, dry at 60 to 90 ° C for 10 to 60 minutes, irradiate with active energy rays such as ultraviolet rays, and then remove unexposed parts with dilute alkaline aqueous solution such as 0.1 to 5 wt% sodium carbonate aqueous solution Then, a solder pattern image is formed by development. After that, in order to completely cure the film, heat treatment (100 to 180 ° C. for 5 to 60 minutes) as a final curing using a hot air dryer or far infrared rays or the like makes two or more epoxy groups in one molecule. When (meth) acrylic acid esters are used as the acid-modified epoxy (meth) acrylate compound (A) and the diluent (D) in addition to the curing reaction of the epoxy compound (B) having (meth) acrylic acid esters Polymerization is promoted, and a cured film having excellent adhesion, heat resistance, and mechanical properties can be obtained. Furthermore, if necessary, for example, by heating to a temperature of 140 to 180 ° C. and thermosetting, and further, (meth) acrylic acid-modified epoxy (meth) acrylate compound (A) and diluent (D) For the purpose of accelerating the polymerization of acid esters, it is possible to obtain a cured film having excellent characteristics by exposing it again to ultraviolet rays (light).

  The irradiation light source for ultraviolet (light) curing is not particularly limited. For example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp, or a metal halide lamp can be used.

  Examples of the present invention will be described below. However, the following examples do not limit the scope of the present invention.

  In this embodiment, “parts” means parts by weight unless otherwise specified. In this example, the multi-branched polyester (meth) acrylate compound resin means that the multi-branched polyester (meth) acrylate compound is diluted with an organic solvent and / or a diluent of (meth) acrylic acid esters. means.

  Synthesis example of hyperbranched polyester polyol (a) used for hyperbranched polyester (meth) acrylate compound (A)

Synthesis Example 1 (Multi-branched polyester polyol (a) -1)
A flask equipped with a stirrer, a gas introduction tube, a packed tower, and a thermometer was charged with 389.7 g of terephthalic acid, 248.4 g of glycerin, and 246.3 g of bisphenol A propylene oxide adduct (molecular weight 350). The dehydration condensation reaction was performed. The reaction was terminated when the acid value reached 3 mgKOH / g. As a result of the GPC measurement and the hydroxyl value measurement, a multi-branched polyester polyol (a) -1 having a number average molecular weight of 1600 having an average of 10 hydroxyl groups was obtained.

Synthesis Example 2 (Multi-branched polyester polyol (a) -2)
An apparatus similar to Synthesis Example 1 was charged with 470.3 g of isophthalic acid, 247.6 g of glycerin, and 184.0 g of bisphenol A ethylene oxide adduct (molecular weight 325), and a dehydration condensation reaction was performed at 220 ° C. under a nitrogen flow. The reaction was terminated when the acid value reached 0.5 mgKOH / g. As a result of GPC measurement and hydroxyl value measurement, a multi-branched polyester polyol (a) -2 having a number average molecular weight of 7200 having an average of 32 hydroxyl groups was obtained.

Synthesis Example 3 (Multi-branched polyester polyol (a) -3)
In the same apparatus as in Synthesis Example 1, 513.0 g of isophthalic acid and 398.1 g of glycerin were charged, and a dehydration condensation reaction was performed at 220 ° C. under a nitrogen flow. The reaction was terminated when the acid value reached 1 mgKOH / g. As a result of the GPC measurement and the hydroxyl value measurement, a multi-branched polyester polyol (a) -3 having a number average molecular weight of 700 having an average of 6 hydroxyl groups was obtained.

Synthesis Example 4 (multi-branched polyester polyol (a) -4)
In the same apparatus as in Synthesis Example 1, 589.8 g of isophthalic acid and 338.0 g of glycerin were charged, and a dehydration condensation reaction was performed under a nitrogen flow at 240 ° C. The reaction was terminated when the acid value reached 0.2 mgKOH / g. As a result of GPC measurement and hydroxyl value measurement, a hyperbranched polyester polyol (a) -4 having a number average molecular weight of 13,000 having an average of 64 hydroxyl groups was obtained.

Synthesis Example 5 (Polyester polyol (a) -5)
In the same apparatus as in Synthesis Example 1, 470.26 g of isophthalic acid and 1109.7 g of bisphenol A ethylene oxide adduct (molecular weight 325) were charged, and a dehydration condensation reaction was performed at 240 ° C. under a nitrogen stream. The reaction was terminated when the acid value reached 0.2 mgKOH / g. As a result of the GPC measurement and the hydroxyl value measurement, a multi-branched polyester polyol (a) -5 having a number average molecular weight of 2600 having an average of 2 hydroxyl groups was obtained.

Synthesis example of hyperbranched polyester (meth) acrylate compound (A) Synthesis example 6 (hyperbranched polyester (meth) acrylate compound (A) -1)
Into a flask equipped with a stirrer, a gas introduction tube, a packed tower, and a thermometer, 400.00 g of compound (a) -1 obtained in Synthesis Example 1 was charged and dissolved, and then 87.83 g of 2-acryloyloxyethyl isocyanate. Then, 0.25 g of toluhydroquinone was added, and the mixture was reacted at 120 ° C. with stirring and air flow. The reaction was traced by IR measurement, and the time when the peak derived from the isocyanate group in the vicinity of 2380 cm −1 disappeared was taken as the reaction end point. When the isocyanate group concentration was titrated, it was 0%. After completion of the reaction, the reaction mixture was diluted with diethylene glycol monoethyl ether acetate so that the solid content became 70%. Subsequently, 135.09 g of tetrahydrophthalic anhydride and 1.25 g of triphenylphosphine were added, and the mixture was reacted at a reaction temperature of 110 ° C. for 8 hours under stirring and air flow. After completion of the reaction, diethylene glycol monoethyl ether acetate was added so that the solid content was 65% to obtain a multi-branched polyester (meth) acrylate compound (A) -1 having an acrylic equivalent of 1000 and a solid content acid value of 80 mgKOH / g.

Synthesis Example 7 (Multi-branched polyester (meth) acrylate compound (A) -2)
In a device similar to Synthesis Example 5, 400.00 g of Compound (a) -1 obtained in Synthesis Example 1 was charged and dissolved, and then 80.99 g of 2-acryloyloxyethyl isocyanate and 0.23 g of toluhydroquinone were added. The reaction was conducted in the same manner as in Synthesis Example 5. After completion of the reaction, the reaction mixture was diluted with diethylene glycol monoethyl ether acetate so that the solid content became 70%. Subsequently, 93.43 g of tetrahydrophthalic anhydride and 1.15 g of triphenylphosphine were added and reacted in the same manner as in Synthesis Example 5. After completion of the reaction, diethylene glycol monoethyl ether acetate was added so that the solid content was 65% to obtain a multi-branched polyester (meth) acrylate compound (A) -2 having an acrylic equivalent of 1000 and a solid content acid value of 60 mgKOH / g.

Synthesis Example 8 (Multi-branched polyester (meth) acrylate compound (A) -3)
In a device similar to Synthesis Example 5, 400.00 g of Compound (a) -2 obtained in Synthesis Example 2 was charged and dissolved, and then 87.83 g of 2-acryloyloxyethyl isocyanate and 0.25 g of toluhydroquinone were added, The reaction was conducted in the same manner as in Synthesis Example 5. After completion of the reaction, the reaction mixture was diluted with diethylene glycol monoethyl ether acetate so that the solid content became 70%. Next, 135.09 g of tetrahydrophthalic anhydride and 1.25 g of triphenylphosphine were added and reacted in the same manner as in Synthesis Example 5. After completion of the reaction, diethylene glycol monoethyl ether acetate was added so that the solid content was 65% to obtain a multi-branched polyester (meth) acrylate compound (A) -3 having an acrylic equivalent of 1000 and a solid content acid value of 80 mgKOH / g.

Synthesis Example 9 (Multi-branched polyester (meth) acrylate compound (A) -4)
In a device similar to Synthesis Example 5, 400.00 g of Compound (a) -2 obtained in Synthesis Example 2 was charged and dissolved, and then 80.99 g of 2-acryloyloxyethyl isocyanate and 0.23 g of toluhydroquinone were added. The reaction was conducted in the same manner as in Synthesis Example 5. After completion of the reaction, the reaction mixture was diluted with diethylene glycol monoethyl ether acetate so that the solid content became 70%. Subsequently, 93.43 g of tetrahydrophthalic anhydride and 1.15 g of triphenylphosphine were added and reacted in the same manner as in Synthesis Example 5. After completion of the reaction, diethylene glycol monoethyl ether acetate was added so that the solid content was 65% to obtain a multi-branched polyester (meth) acrylate compound (A) -4 having an acrylic equivalent of 1000 and a solid content acid value of 60 mgKOH / g.

Synthesis Example 10 (Multi-branched polyester (meth) acrylate compound (A) -5)
In a device similar to Synthesis Example 5, 400.00 g of Compound (a) -1 obtained in Synthesis Example 1 was charged and dissolved, and then 126.70 g of 2-acryloyloxyethyl isocyanate and 0.27 g of toluhydroquinone were added, The reaction was conducted in the same manner as in Synthesis Example 5. After completion of the reaction, the reaction mixture was diluted with diethylene glycol monoethyl ether acetate so that the solid content became 70%. Then, 102.30 g of tetrahydrophthalic anhydride and 1.33 g of triphenylphosphine were added and reacted in the same manner as in Synthesis Example 5. After completion of the reaction, diethylene glycol monoethyl ether acetate was added so that the solid content was 65% to obtain a multi-branched polyester (meth) acrylate compound (A) -5 having an acrylic equivalent of 700 and a solid content acid value of 60 mgKOH / g.

Synthesis Example 11 (Multi-branched polyester (meth) acrylate compound (A) -6)
In a device similar to Synthesis Example 5, 400.00 g of Compound (a) -1 obtained in Synthesis Example 1 was charged and dissolved, and then 78.28 g of 2-acryloyloxyethyl isocyanate and 0.24 g of toluhydroquinone were added, The reaction was conducted in the same manner as in Synthesis Example 5. After completion of the reaction, the reaction mixture was diluted with diethylene glycol monoethyl ether acetate so that the solid content became 70%. Then, 132.44 g of tetrahydrophthalic anhydride and 1.22 g of triphenylphosphine were added and reacted in the same manner as in Synthesis Example 5. After completion of the reaction, diethylene glycol monoethyl ether acetate was added so that the solid content was 65%, to obtain a multi-branched polyester (meth) acrylate compound (A) -6 having an acrylic equivalent of 1100 and a solid content acid value of 80 mgKOH / g.

Synthesis Example 12 (Multi-branched polyester (meth) acrylate compound (A) -7)
In a device similar to Synthesis Example 5, 400.00 g of Compound (a) -3 obtained in Synthesis Example 3 was charged and dissolved, and then 87.83 g of 2-acryloyloxyethyl isocyanate and 0.25 g of toluhydroquinone were added, The reaction was conducted in the same manner as in Synthesis Example 5. After completion of the reaction, the reaction mixture was diluted with diethylene glycol monoethyl ether acetate so that the solid content became 70%. Next, 135.09 g of tetrahydrophthalic anhydride and 1.25 g of triphenylphosphine were added and reacted in the same manner as in Synthesis Example 5. After completion of the reaction, diethylene glycol monoethyl ether acetate was added so that the solid content was 65%, to obtain a multi-branched polyester (meth) acrylate compound (A) -7 having an acrylic equivalent of 1000 and a solid content acid value of 80 mgKOH / g.

Synthesis Example 13 (Multi-branched polyester (meth) acrylate compound (A) -8)
In a device similar to Synthesis Example 5, 400.00 g of Compound (a) -4 obtained in Synthesis Example 4 was charged and dissolved, and then 87.83 g of 2-acryloyloxyethyl isocyanate and 0.25 g of toluhydroquinone were added, The reaction was conducted in the same manner as in Synthesis Example 5. After completion of the reaction, the reaction mixture was diluted with diethylene glycol monoethyl ether acetate so that the solid content became 70%. Next, 135.09 g of tetrahydrophthalic anhydride and 1.25 g of triphenylphosphine were added and reacted in the same manner as in Synthesis Example 5. After completion of the reaction, diethylene glycol monoethyl ether acetate was added so that the solid content was 65% to obtain a multi-branched polyester (meth) acrylate compound (A) -8 having an acrylic equivalent of 1000 and a solid content acid value of 80 mgKOH / g.

Synthesis Example 14 (Multi-branched polyester (meth) acrylate compound (A) -9)
In a device similar to Synthesis Example 5, 400.00 g of Compound (a) -1 obtained in Synthesis Example 1 was charged and dissolved, and then 203.11 g of 2-acryloyloxyethyl isocyanate and 0.29 g of toluhydroquinone were added, The reaction was conducted in the same manner as in Synthesis Example 5. After completion of the reaction, the reaction mixture was diluted with diethylene glycol monoethyl ether acetate so that the solid content became 70%. Subsequently, 117.15 g of tetrahydrophthalic anhydride and 1.44 g of triphenylphosphine were added and reacted in the same manner as in Synthesis Example 5. After completion of the reaction, diethylene glycol monoethyl ether acetate was added so that the solid content was 65% to obtain a multi-branched polyester (meth) acrylate compound (A) -9 having an acrylic equivalent of 500 and a solid content acid value of 60 mgKOH / g.

Synthesis Example 15 (Multi-branched polyester (meth) acrylate compound (A) -10)
In a device similar to Synthesis Example 5, 400.00 g of Compound (a) -1 obtained in Synthesis Example 1 was charged and dissolved, and then 59.03 g of 2-acryloyloxyethyl isocyanate and 0.23 g of toluhydroquinone were added, The reaction was conducted in the same manner as in Synthesis Example 5. After completion of the reaction, the reaction mixture was diluted with diethylene glycol monoethyl ether acetate so that the solid content became 70%. Then, 127.11 g of tetrahydrophthalic anhydride and 1.17 g of triphenylphosphine were added and reacted in the same manner as in Synthesis Example 5. After completion of the reaction, diethylene glycol monoethyl ether acetate was added so that the solid content was 65%, to obtain a multi-branched polyester (meth) acrylate compound (A) -10 having an acrylic equivalent of 1400 and a solid content acid value of 80 mgKOH / g.

Synthesis Example 16 (Multi-branched polyester (meth) acrylate compound (A) -11)
After charging 400.00 g of the compound (a) -1 obtained in Synthesis Example 1 and dissolving it in the same apparatus as in Synthesis Example 5, 72.52 g of 2-acryloyloxyethyl isocyanate and 0.21 g of toluhydroquinone were added, The reaction was conducted in the same manner as in Synthesis Example 5. After completion of the reaction, the reaction mixture was diluted with diethylene glycol monoethyl ether acetate so that the solid content became 70%. Subsequently, 41.83 g of tetrahydrophthalic anhydride and 1.03 g of triphenylphosphine were added and reacted in the same manner as in Synthesis Example 5. After completion of the reaction, diethylene glycol monoethyl ether acetate was added so that the solid content was 65%, to obtain a multi-branched polyester (meth) acrylate compound (A) -11 having an acrylic equivalent of 1000 and a solid content acid value of 30 mgKOH / g.

Synthesis Example 17 (Multi-branched polyester (meth) acrylate compound (A) -12)
After charging 400.00 g of the compound (a) -1 obtained in Synthesis Example 1 and dissolving it in the same apparatus as in Synthesis Example 5, 105.68 g of 2-acryloyloxyethyl isocyanate and 0.30 g of toluhydroquinone were added, The reaction was conducted in the same manner as in Synthesis Example 5. After completion of the reaction, the reaction mixture was diluted with diethylene glycol monoethyl ether acetate so that the solid content became 70%. Subsequently, 243.79 g of tetrahydrophthalic anhydride and 1.50 g of triphenylphosphine were added and reacted in the same manner as in Synthesis Example 5. After completion of the reaction, diethylene glycol monoethyl ether acetate was added so that the solid content was 65%, to obtain a multi-branched polyester (meth) acrylate compound (A) -12 having an acrylic equivalent of 1000 and a solid content acid value of 120 mgKOH / g.

Synthesis Example 18 (Polyester (meth) acrylate compound (A) -13)
In a device similar to Synthesis Example 5, 520.00 g of Compound (a) -5 obtained in Synthesis Example 5 was charged and dissolved, and then 28.23 g of 2-acryloyloxyethyl isocyanate and 0.32 g of toluhydroquinone were added, The reaction was conducted in the same manner as in Synthesis Example 5. After completion of the reaction, the reaction mixture was diluted with diethylene glycol monoethyl ether acetate so that the solid content became 70%. Then, 30.42 g of tetrahydrophthalic anhydride and 1.67 g of triphenylphosphine were added and reacted in the same manner as in Synthesis Example 5. After completion of the reaction, diethylene glycol monoethyl ether acetate was added so that the solid content was 65%, to obtain a polyester (meth) acrylate compound (A) -13 having an acrylic equivalent of 2893 and a solid content acid value of 19.3 mgKOH / g.

Synthesis Example 19 (Novolac acrylate compound (E) -1)
424.00 g of cresol novolac type epoxy resin (epoxy equivalent 212) was charged into the same apparatus as in Synthesis Example 5 and dissolved, and then 144.12 g of acrylic acid, 0.11 g of triphenylphosphine, and 0.23 g of toluhydroquinone were added. The reaction was continued under stirring and air flow at a reaction temperature of 120 ° C. until the acid value reached 1 mgKOH / g. After completion of the reaction, the reaction mixture was diluted with diethylene glycol monoethyl ether acetate so that the solid content became 70%. Subsequently, 211.27 g of tetrahydrophthalic anhydride was added, and the mixture was reacted for 8 hours at 110 ° C. under a stream of air with stirring. After completion of the reaction, diethylene glycol monoethyl ether acetate was added so that the solid content was 65% to obtain a novolak acrylate compound (E) -1 having an acrylic equivalent of 390 and a solid content acid value of 100 mgKOH / g.

Synthesis Example 20 (Bisphenol type polyfunctional acrylate compound (E) -2)
In the same apparatus as in Synthesis Example 5, 70 g of pyromellitic anhydride, 97 g of 4-hydroxybutyl acrylate, and 0.3 g of triphenylphosphine were added, and 46 g of acrylic acid was added to lower the viscosity during the reaction, and air was blown The mixture was heated with stirring to maintain the temperature at 85 to 95 ° C. for reaction. The reaction was followed by IR and continued until absorption of unreacted pyromellitic anhydride (1780 cm @ -1) disappeared. The reaction took 6 hours. Next, 216 g of a bisphenol F-type epoxy compound (trade name “Epicron 830S” manufactured by Dainippon Ink and Chemicals, Inc.), 1.0 g of triphenylphosphine, and 2.6 parts of monomethyl ether hydroquinone were charged, and the temperature was increased by stirring. The reaction was carried out for 10 hours while maintaining at 110 to 120 ° C. to obtain a reaction product having an acid value of 1 mgKOH / g. Thereafter, 161.0 g of tetrahydrophthalic anhydride was added, the temperature was maintained at 100 to 110 ° C. with stirring, and the mixture was further reacted for 5 hours to obtain an acid-modified epoxy methacrylate compound having an acid value of 100 mgKOH / g. After completion of the reaction, diethylene glycol monoethyl ether acetate was added so that the solid content was 65%, to obtain a bisphenol type polyfunctional acrylate compound (E) -2 having an acrylic equivalent of 500 and a solid content acid value of 100 mgKOH / g.

Examples 1-13, Comparative Examples 1-2
Using each of the resins obtained in Synthesis Examples 6 to 20, photosensitive thermosetting resin compositions having the formulations shown in Tables 1 and 2 were kneaded with a three-roll mill. Table 1 shows the resin contents and compositions of Examples 1-8.

Table 2 shows the resin contents and compositions of Examples 9-13 and Comparative Examples 1-2.

  The performance evaluation of each composition is shown in Table 3.

The performance evaluation was performed by the following method.
(1) Touch dryness (tackiness at the time of solvent dry removal)
The composition of each of the above examples and comparative examples was applied to the entire surface of a copper foil substrate by screen printing, dried at 80 ° C. for 30 minutes in a hot air drying furnace, and allowed to cool, while the coating film surface temperature was 40 ° C. And at the time of room temperature (23 degreeC), the finger touch drying property of the coating film was confirmed with the finger | toe. Judgment criteria are as follows.
○: There is no tack. Δ: There is a little tack. X: There is a tack.

(2) Alkali developability The composition of each of the above examples and comparative examples was applied onto the copper foil substrate by screen printing, dried at 80 ° C. for 30 minutes in a hot air drying furnace, and allowed to cool to room temperature. Then, a 1% Na ₂ CO ₃ aqueous solution at 30 ° C. was developed for 60 seconds under the condition of a spray pressure of 0.2 MPa, and the presence or absence of the development residue of the dried coating film was visually confirmed. Judgment criteria are as follows.
○: Completely developed. Δ: A part of the coating film remains. X: The coating film remains completely.

(3) Sensitivity The compositions of the above Examples and Comparative Examples were applied to the entire surface of a copper foil substrate (thickness: 1.6 mm) by screen printing, dried at 80 ° C. for 30 minutes in a hot air drying oven, and room temperature. After standing to cool, a step labret (Kodak No. ² , 21 steps) is placed on the coating film, exposed at an exposure amount of 400 mJ / cm ² , and sprayed with a 1% Na ₂ CO ₃ aqueous solution at 30 ° C. at a spray pressure of 0. Development was performed for 60 seconds under the condition of 2 MPa, and the number of steps of the remaining coating film was evaluated by visual observation.

(4) Adhesiveness The composition of each of the above Examples and Comparative Examples was applied on the entire surface of a polyimide film (thickness 50 μm) by screen printing, dried at 80 ° C. for 30 minutes in a hot air drying oven, and then released to room temperature. After cooling, the film was exposed at an exposure dose of 400 mJ / cm ² , cured at 150 ° C. for 60 minutes in a hot air drying furnace, and allowed to cool to room temperature (film thickness 20 μm). The adhesion of the cured coating film was evaluated according to the following criteria according to JIS D0202.
○: The number of grids remaining completely. Δ: Number of grids less than 100, remaining 60 or more. X: The number of grids remaining less than 60.

(5) Folding resistance The compositions of the above Examples and Comparative Examples were applied onto the polyimide film (thickness 25 μm) by screen printing, dried in a hot air drying oven at 80 ° C. for 30 minutes, and brought to room temperature. After allowing to cool, the film was exposed to light having an exposure dose of 400 mJ / cm ² , cured at 150 ° C. for 60 minutes in a hot air drying furnace, and allowed to cool to room temperature (film thickness 20 μm). The folding resistance of the cured coating film was evaluated by the following criteria by bending the obtained cured coating film 180 °, observing the portion with a microscope.
○: The cured coating film has no cracks. Δ: The cured coating film has some cracks.
X: The cured coating film has a crack.

(6) Warpage property The composition of each of the above examples and comparative examples was applied on the entire surface of a 5 cm square polyimide film (thickness 25 μm) by screen printing, and dried at 80 ° C. for 30 minutes in a hot air drying oven. After being allowed to cool to room temperature, it was exposed under conditions of an exposure dose of 400 mJ / cm ² , cured at 150 ° C. for 60 minutes in a hot air drying furnace, and allowed to cool to room temperature (film thickness 20 μm). The warpage of the cured coating film was measured by measuring the height at which the four corners of the 5 cm square film were warped, and the average value was evaluated according to the following criteria.
○: Warping up is less than 1 mm. (Triangle | delta): The thing whose curvature rises 1 mm or more and less than 5 mm. X: Warping up is 5 mm or more.

(7) Solder heat resistance The composition of each of the above Examples and Comparative Examples was applied to the entire surface of a copper foil substrate (1.6 mm) by screen printing, dried in a hot air drying oven at 80 ° C. for 30 minutes, and room temperature. Then, the film was exposed to light at an exposure dose of 400 mJ / cm ² , cured at 150 ° C. for 60 minutes in a hot air drying furnace, and allowed to cool to room temperature (film thickness 20 μm). A rosin-based flux was applied to the obtained cured coating film and immersed in a solder bath at 260 ° C. for 10 seconds (twice), and the state of the coating film was evaluated according to the following criteria.
○: The cured coating film does not blister, peel off or discolor. Δ: Slightly swollen, peeled off or discolored on the cured coating film. X: The cured coating film has blistering, peeling and discoloration.

(8) Chemical resistance The composition of each of the above Examples and Comparative Examples was applied to the entire surface of a copper foil substrate (1.6 mm) by screen printing, dried in a hot air drying oven at 80 ° C. for 30 minutes, and room temperature. Then, the film was exposed to light at an exposure dose of 400 mJ / cm ² , cured at 150 ° C. for 60 minutes in a hot air drying furnace, and allowed to cool to room temperature (film thickness 20 μm). Next, after the whole surface was immersed in 10% hydrochloric acid for 30 minutes, the adhesion was evaluated according to the following criteria according to JIS D0202.
○: The number of grids remains completely and there is no swelling or discoloration. X: The number of grids is one or more peeled, swollen or discolored.

(9) PCT resistance The compositions of the above Examples and Comparative Examples were applied to the entire surface of a copper foil substrate (1.6 mm) by screen printing, dried in a hot air drying oven at 80 ° C. for 30 minutes, and brought to room temperature. After allowing to cool, the film was exposed to light having an exposure dose of 400 mJ / cm ² , cured at 150 ° C. for 60 minutes in a hot air drying furnace, and allowed to cool to room temperature (film thickness 20 μm). The PCT resistance of the obtained cured coating film was evaluated according to the following criteria under the conditions of 121 ° C. and saturation of 50 hours.
○: The cured coating film does not blister, peel off or discolor. Δ: Slightly swollen, peeled off or discolored on the cured coating film. X: The cured coating film has blistering, peeling and discoloration.

(10) Glass transition temperature The composition of each of the above Examples and Comparative Examples was applied to a Teflon (registered trademark) plate by screen printing, dried at 80 ° C. for 30 minutes in a hot air drying furnace, and allowed to cool to room temperature. Then, the film was exposed to light at an exposure amount of 400 mJ / cm ² , cured at 150 ° C. for 60 minutes in a hot air drying furnace, and allowed to cool to room temperature (film thickness 20 μm). Thereafter, the cured cured coating film was peeled off from the Teflon (registered trademark) plate to obtain an evaluation sample. The glass transition temperature of this evaluation sample was measured by the DMA method.

  The compound of the present invention can be applied to, for example, a photosensitive thermosetting resin composition for solder resist for flexible printed wiring boards. In addition, the photosensitive thermosetting resin composition produced using the compound of the present invention has excellent properties such as ultraviolet curing, developability with an alkaline aqueous solution, chemical resistance, electrical insulation, adhesion, and folding resistance. It is extremely practical.

Claims (9)

  A multibranched polyester (meth) acrylate compound (A) obtained by reacting a multibranched polyester polyol (a), an unsaturated group-containing monoisocyanate (b), and a polybasic acid anhydride (c).   The multibranched polyester (meth) acrylate compound according to claim 1, which is obtained by reacting a polybasic acid anhydride (c) with a reaction product of a multibranched polyester polyol (a) and an unsaturated group-containing monoisocyanate (b). A).   The multibranched polyester (meth) acrylate compound (A) according to claim 1 or 2, wherein the multibranched polyester polyol (a) is synthesized from an alcohol having two or more hydroxyl groups and a polycarboxylic acid.   The multibranched polyester (meth) acrylate compound (A) according to any one of claims 1 to 3, wherein the multibranched polyester polyol (a) contains an alcohol having 3 or more hydroxyl groups as an essential component.   The polyfunctional polyester (meta) according to any one of claims 1 to 4, wherein the multi-branched polyester polyol (a) has an average number of hydroxyl groups (number average molecular weight / hydroxyl group equivalent) per molecule of 8 to 32. ) Acrylate compound (A).   The multi-functional polyester (meth) acrylate compound (A) according to any one of claims 1 to 5, wherein the polyfunctional polyester (meth) acrylate compound (A) has a carboxyl group in the range of 50 to 110 mgKOH / g. ).   The multi-branched polyester (meth) according to any one of claims 1 to 6, wherein the polyfunctional polyester (meth) acrylate compound (A) has a (meth) acryloyl group equivalent in the range of 600 to 1200 g / eq. Acrylate compound (A).   The multibranched polyester (meth) acrylate compound (A) according to any one of claims 1 to 7, an epoxy compound (B) having two or more epoxy groups in one molecule, a photopolymerization initiator ( A photosensitive thermosetting resin composition comprising C) and a diluent (D) as essential components.   A cured product obtained by curing the photosensitive thermosetting resin composition according to claim 8.