JP2010191215A - Photosensitive thermosetting resin composition and flexible printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive thermosetting resin composition for giving excellent flame retardancy without using a brominated epoxy resin or a halogen-based flame retardant, having excellent resolution, adhesiveness, heat resistance, chemical resistance and folding resistance, and suppressing generation of harmful gas such as hydrogen bromide and dioxins during combustion. <P>SOLUTION: The photosensitive thermosetting resin composition includes: (A) a resin component having a (meth)acryloyl group and a carboxyl group in one molecule and soluble with a diluted alkali solution; (B) a thermosetting component having an epoxy group; (C) a (meth)acryloyl group-containing phosphorus compound expressed by general formula [1], wherein R<SP>1</SP>represents hydrogen or a methyl group; (D) a phosphazene compound; (E) a photopolymerization initiator; and (F) a diluent. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention can obtain excellent flame retardancy without using brominated epoxy resin or halogen-based flame retardant, and has excellent resolution, adhesion, heat resistance, chemical resistance, folding resistance, and combustion The present invention relates to a photosensitive thermosetting resin composition in which generation of harmful gases such as hydrogen bromide and dioxins is suppressed, and a flexible printed wiring board using the same.

  Cover coat or solder to protect the wiring pattern formed on the substrate by screen printing or other methods from the external environment and to prevent solder from attaching to unnecessary parts when surface mounting electronic components on the printed wiring board. A protective film called a mask is used. Such a protective film is made of, for example, an epoxy resin composition, but cannot be used as it is because the epoxy resin easily burns. Therefore, in order to impart flame retardancy, a halogen-based flame retardant is added, or an epoxy resin having bromine in the skeleton is used (for example, see Patent Document 1).

  However, since it was reported that decabromophenyl oxide, the most typical brominated flame retardant, produced toxic brominated dibenzooxide and furan during incineration, the safety of brominated flame retardants as a whole was suspected. Yes. In addition, conventional resins using brominated flame retardants also generate a harmful gas such as dioxins during incineration, so the environmental impact during incineration and disposal is large.

  Furthermore, in recent years, organophosphorous flame retardants have been used in place of brominated flame retardants in response to environmental problems. However, organophosphorous flame retardants do not necessarily have excellent flame retardancy, and when imparting the same flame retardance as brominated flame retardants, they must be added in large amounts compared to brominated flame retardants, resulting in reduced characteristics. There are problems such as bleed. In order to improve such characteristic deterioration, for example, a resin system using a specific compound has been studied, but it has not yet had sufficient characteristics (for example, see Patent Documents 2 and 3). .)

JP-A-9-54434 JP 2001-72835 A JP 2007-147720 A

  The present invention has been made to solve the above-mentioned problems, and can provide excellent flame retardancy without using brominated epoxy resin or halogen-based flame retardant, and has resolution, adhesion, and heat resistance. Another object of the present invention is to provide a photosensitive thermosetting resin composition that has excellent chemical resistance and folding resistance, and suppresses the generation of harmful gases such as hydrogen bromide and dioxins during combustion. Further, the present invention is a flexible printed wiring which is excellent in flame retardancy obtained by using the above-described photosensitive thermosetting resin composition, and in which generation of harmful gases such as hydrogen bromide and dioxins during combustion is suppressed. The purpose is to provide a board.

（但し、式中、Ｒ^１は水素またはメチル基を示す。）
（Ｄ）ホスファゼン化合物、（Ｅ）光重合開始剤、および（Ｆ）希釈剤を含有することを特長とする。 The photosensitive thermosetting resin composition of the present invention is an alkali development type photosensitive thermosetting resin composition having (A) a (meth) acryloyl group and a carboxyl group in one molecule. A resin component soluble in an alkaline solution, (B) a thermosetting component having an epoxy group, (C) a (meth) acryloyl group-containing phosphorus compound represented by the following general formula [1],

(In the formula, R ¹ represents hydrogen or a methyl group.)
It contains (D) a phosphazene compound, (E) a photopolymerization initiator, and (F) a diluent.

（但し、式中、Ｒ^２、Ｒ^３は、同一または互いに異なって、水素原子、アミノ基、またはハロゲンを含まない炭素数１〜１２以下の１価の有機基を示し、Ｒ^４、Ｒ^５は、同一または互いに異なって、水素原子、水酸基、または炭素数１〜１２以下の１価の有機基を示し、ｍは３以上１０以下の整数を示す。）

（但し、式中、Ｒ^６、Ｒ^７は、同一または互いに異なって、水素原子、アミノ基、またはハロゲンを含まない炭素数１〜１２以下の１価の有機基を示し、ｎは３以上１０以下の整数を示す。） In the photosensitive thermosetting resin composition of the present invention, the (D) phosphazene compound preferably contains a phosphazene oligomer represented by the following general formula [2] or [3].

^(Wherein, R 2, ^{R 3} are the same or different from each other, a hydrogen atom, an amino group or a monovalent organic group having 1 to 12 carbon atoms containing no ^halogen,, R 4, ^{R 5} Are the same or different from each other, and each represents a hydrogen atom, a hydroxyl group, or a monovalent organic group having 1 to 12 carbon atoms, and m represents an integer of 3 to 10.

(In the formula, R ⁶ and R ⁷ are the same or different from each other, and each represents a hydrogen atom, an amino group, or a monovalent organic group having 1 to 12 carbon atoms that does not contain halogen, and n is 3 or more and 10 The following integers are shown.)

  Moreover, in the photosensitive thermosetting resin composition of the present invention, 1 part by mass of the thermosetting component (B) having an epoxy group with respect to 100 parts by mass of the resin component (A) soluble in the dilute alkali solution. 100 parts by mass or less, (C) (meth) acryloyl group-containing phosphorus compound 1 part by mass to 50 parts by mass, (D) phosphazene compound 1 part by mass to 50 parts by mass, (E) photopolymerization initiator It is preferable to contain 1 to 50 parts by mass and 1 to 100 parts by mass of the diluent (F).

  The flexible printed wiring board of the present invention is a flexible printed wiring board having a polyimide layer and a copper layer laminated on at least one main surface of the polyimide layer, and the above-described flexible printed wiring board of the present invention is formed on at least one main surface. It has the resin layer which consists of a photosensitive thermosetting resin composition, It is characterized by the above-mentioned.

  According to the present invention, a specific (meth) acryloyl group-containing phosphorus compound and a phosphazene compound are used in combination, and in particular, by using a specific phosphazene compound in combination as a phosphazene compound, a brominated epoxy resin or a halogen-based flame retardant is used. Excellent flame retardancy can be obtained without using it, and it has excellent resolution, adhesion, heat resistance, chemical resistance and folding resistance, and generation of harmful gases such as hydrogen bromide and dioxins during combustion. A suppressed photosensitive thermosetting resin composition can be provided. Further, according to the present invention, by using such a photosensitive thermosetting resin composition, it is excellent in flame retardancy and the like, and generation of harmful gases such as hydrogen bromide and dioxins during combustion is suppressed. A flexible printed wiring board can be provided.

（但し、式中、Ｒ^１は水素またはメチル基を示す。） The photosensitive thermosetting resin composition of the present invention (hereinafter simply referred to as a resin composition) is an alkali development type resin composition, which comprises (A) a (meth) acryloyl group and a carboxyl group in one molecule. And a resin component soluble in a dilute alkali solution, (B) a thermosetting component having an epoxy group, (C) a (meth) acryloyl group-containing phosphorus compound represented by the following general formula [1], (D) a phosphazene compound And (E) a photopolymerization initiator, and (F) a diluent.

(In the formula, R ¹ represents hydrogen or a methyl group.)

  The resin component soluble in the diluted alkaline solution (A) has a (meth) acryloyl group and a carboxyl group in one molecule, and is soluble in the diluted alkaline solution. This resin component is one in which the (meth) acryloyl group in the molecule is polymerized by radicals generated from the photopolymerization initiator of the component (E) by irradiation with active energy rays such as ultraviolet rays, and as a result, the resin composition is insolubilized. is there.

  As a resin component soluble in such a dilute alkaline solution, for example, an epoxy acrylate compound (for example, an epoxy resin obtained by esterifying (meth) acrylic acid to an epoxy resin to be acrylic-modified and further adding an acid anhydride) Epoxy acrylate oligomer).

  As an epoxy resin used for the synthesis | combination of this epoxy acrylate compound, a well-known epoxy resin is mentioned, Especially a bisphenol-type epoxy resin is mentioned as a suitable thing. Moreover, as (meth) acrylic acid used for the synthesis | combination of an epoxy acrylate compound, acrylic acid, methacrylic acid, and a mixture thereof are mentioned, for example. Furthermore, examples of acid anhydrides used for the synthesis of epoxy acrylate compounds include phthalic anhydride, succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, and methyltetrahydrophthalic anhydride. Acid, itaconic anhydride, methylendomethylenetetrahydrophthalic anhydride and the like can be mentioned, and succinic anhydride and phthalic anhydride are particularly preferable.

  The resin component soluble in the dilute alkaline solution of component (A) includes, for example, a polyol compound, a polybasic acid anhydride having two anhydrides in the molecule, and one epoxy group in the molecule. Examples thereof include a carboxyl group-containing urethane compound (for example, a carboxyl group-containing urethane oligomer) obtained by reacting with (meth) acrylic acid.

  The resin component soluble in the dilute alkali solution of component (A) preferably has an acid value of 50 mgKOH / g or more and 200 mgKOH / g or less. If the acid value is less than 50 mgKOH / g, the alkali solubility may be reduced and alkali development may be difficult. If it exceeds 200 mgKOH / g, the film may be greatly reduced during development, and the resolution may be significantly reduced. is there. The acid value of the alkali-soluble component (A) is preferably 80 mgKOH / g or more and 150 mgKOH / g or less.

  The content of the resin component soluble in the dilute alkali solution of the component (A) is preferably 20% by mass or more and 70% by mass or less in the entire resin composition. If the content of the resin component soluble in the dilute alkali solution of component (A) is less than 20% by mass, insolubilization of the resin composition by irradiation with active energy rays may not be sufficient, and 70% by mass When it exceeds, there exists a possibility that the heat resistance of a resin composition, etc. may become insufficient.

  (B) The thermosetting component which has an epoxy group of a component is a compound which has 1 or more glycidyl ether groups in a molecule | numerator, for example, Specifically, what is generally called an epoxy resin is mentioned. Such an epoxy resin is not particularly limited and is, for example, a glycidyl etherified product of a polyphenol compound such as bisphenol A, bisphenol F, bisphenol S, 4,4′-biphenylphenol, phenol novolak, orthocresol novolak, and the like. Glycidyl ethers; glycidyl amines typified by tetraglycidyl diaminodiphenyl methane, tetraglycidyl diaminodiphenyl sulfone, etc. are mentioned, preferably those having an epoxy equivalent of 130 g / eq or more and 1500 g / eq or less are used alone or in combination. be able to.

  (B) As for content of the thermosetting component which has an epoxy group of a component, 1 to 100 mass parts is preferable with respect to 100 mass parts of resin components soluble in the dilute alkali solution of (A) component. If the content of the thermosetting component having an epoxy group as the component (B) is less than 1 part by mass, the heat resistance of the cured product of the resin composition may be insufficient, and if it exceeds 100 parts by mass, the resin There is a possibility that alkali development of the composition is lowered and alkali development becomes difficult.

The resin composition preferably contains an epoxy resin curing agent in order to further improve properties such as adhesion, chemical resistance, and heat resistance. Examples of such epoxy resin curing agents include 2MZ, 2E4MZ, C11Z, C17Z, 2PZ, 1B2MZ, 2MZ-CN, 2E4MZ-CN, C11Z-CN, 2PZ-CN, 2PHZ-CN, 2MZ-CNS, 2E4MZ-CNS. Imidazole derivatives such as 2PZ-CNS, 2MZ-AZINE, 2E4MZ-AZINE, C11Z-AZ1NE, 2MA-OK, 2P4MHZ, 2PHZ and 2P4BHZ (all manufactured by Shikoku Kasei Kogyo Co., Ltd.); guanamines such as acetoguanamine and benzoguanamine; diamino Polyamines such as diphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenylsulfone, dicyandiamide, urea, urea derivatives, melamine, polybasic hydrazides; organic acid salts of these polyamines And / or epoxy adducts; amine complex of boron trifluoride; triazine derivatives such as ethyldiamino-S-triazine, 2,4-diamino-S-triazine, 2,4-diamino-6-xylyl-S-triazine Trimethylamine, triethanolamine, N, N-dimethyloctylamine, N-benzyldimethylamine, pyridine, N-methylmorpholine, hexa (N-methyl) melamine, 2,4,6-tris (dimethylaminophenol), tetra Tertiary amines such as methylguanidine and m-aminophenol; polyphenols such as polyvinylphenol, polyvinylphenol bromide, phenol novolak, and alkylphenol novolak; tributylphosphine, triphenylphosphine, tris-2-cyanoethylphosphine Organic phosphines such as triphenyl, phosphonium salts such as tri-n-butyl (2,5-dihydroxyphenyl) phosphonium bromide and hexadecyltributylphosphonium chloride; quaternary ammonium salts such as benzyltrimethylammonium chloride and phenyltributylammonium chloride, Polybasic acid anhydride; diphenyliodonium tetrafluoroboroate, triphenylsulfonium hexafluoroantimonate, 2,4,6-triphenylthiopyrylium hexafluorophosphate, Irgacure 261 (manufactured by Ciba Geigy), Optomer SP- 170 (Asahi Denka Co., Ltd.) photocationic polymerization catalyst; styrene-maleic anhydride resin; equimolar reaction product of phenyl isocyanate and dimethylamine and tolylene diisocyanate And known curing agents or curing accelerators such as an equimolar reaction product of an organic polyisocyanate such as isophorone diisocyanate and dimethylamine. These may be used alone or in admixture of two or more. it can.

  The content of the epoxy resin curing agent is preferably 0.01 parts by mass or more and 25 parts by mass or less with respect to 100 parts by mass of the resin component soluble in the dilute alkali solution of the component (A), and 0.1 parts by mass. More preferably, it is 15 parts by mass or less. If the content of the epoxy resin curing agent is less than 0.01 parts by mass, the resin composition may not be sufficiently cured, and if it exceeds 25 parts by mass, the heat resistance of the cured product of the resin composition, etc. May decrease.

  The (meth) acrylic group-containing phosphorus compound (C) is polymerized by radicals generated from the photopolymerization initiator (E) by irradiation with active energy rays such as ultraviolet rays, and insolubilizes the resin composition. In combination with the phosphazene compound of component D), it is contained in order to improve various properties including flame retardancy. The (meth) acrylic group-containing phosphorus compound of component (C) is represented by the above general formula [1], and specifically is represented by the following chemical formulas [1a] and [1b].

  Such a (meth) acryl group-containing phosphorus compound can be produced, for example, according to the method described in JP-A-7-48394. (C) As for content of the (meth) acryl group containing phosphorus compound of a component, 1 mass part or more and 50 mass parts or less are preferable with respect to 100 mass parts of resin components soluble in the dilute alkali solution of (A) component. When the content of the (meth) acrylic group-containing phosphorus compound of component (C) is less than 1 part by mass, the flame retardancy of the cured product of the resin composition may not be sufficient, and when it exceeds 50 parts by mass In addition, the adhesiveness of the cured product of the resin composition is lowered, and cracks are easily generated.

  The phosphazene compound as the component (D) is contained in order to improve various properties such as flame retardancy by using in combination with the (meth) acrylic group-containing phosphorus compound as the component (C). As such phosphazene compounds, known phosphazene compounds used for imparting flame retardancy can be used. For example, phosphazene oligomers represented by the following general formulas [2] and [3] can be preferably used. .

（但し、式中、Ｒ^２、Ｒ^３は、同一または互いに異なって、水素原子、アミノ基、またはハロゲンを含まない炭素数１〜１２以下の１価の有機基を示し、Ｒ^４、Ｒ^５は、同一または互いに異なって、水素原子、水酸基、または炭素数１〜１２以下の１価の有機基を示し、ｍは３以上１０以下の整数を示す。）

^(Wherein, R 2, ^{R 3} are the same or different from each other, a hydrogen atom, an amino group or a monovalent organic group having 1 to 12 carbon atoms containing no ^halogen,, R 4, ^{R 5} Are the same or different from each other, and each represents a hydrogen atom, a hydroxyl group, or a monovalent organic group having 1 to 12 carbon atoms, and m represents an integer of 3 to 10.

（但し、式中、Ｒ^６、Ｒ^７は、同一または互いに異なって、水素原子、アミノ基、またはハロゲンを含まない炭素数１〜１２以下の１価の有機基を示し、ｎは３以上１０以下の整数を示す。）

(In the formula, R ⁶ and R ⁷ are the same or different from each other, and each represents a hydrogen atom, an amino group, or a monovalent organic group having 1 to 12 carbon atoms that does not contain halogen, and n is 3 or more and 10 The following integers are shown.)

Examples of the monovalent organic group in R ² , R ³ , R ⁶ and R ⁷ in the general formulas [2] and [3] include an alkyl group, an aryl group, a cyanoaryl group, a cyanate aryl group, and an allyl group. . Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decanyl group. Examples of the aryl group include a phenyl group, a naphthyl group, a biphenyl group, an ethylphenyl group, an isopropylphenyl group, an n-propylphenyl group, an isobutylphenyl group, and a t-butylphenyl group. Examples of the cyanoaryl group include a 4-cyanophenyl group and a 4-cyanobiphenyl group. Examples of the cyanate aryl group include a cyanate phenyl group.

Examples of the monovalent organic group in R ⁴ and R ⁵ which are terminal groups of the general formula [2] include an alkyl group, an aryl group, a cyanoaryl group, a cyanate aryl group, an allyl group, a cyanate group, an alkoxyl group, An aryloxy group is mentioned. Examples of the alkyl group, aryl group, cyanoaryl group, and cyanate aryl group are the same as those described above for R ² and the like. Examples of the alkoxyl group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, nonyloxy group and decyloxy group. Examples of the aryloxy group include a phenoxy group, a 1-naphthyloxy group, and a 2-naphthyloxy group.

  More preferable phosphazene compounds include, for example, propoxyphosphazene oligomers, phenoxyphosphazene oligomers, cyanate phenylphosphazene oligomers, cyanophenoxyphosphazene oligomers, and the like. Furthermore, a phosphazene compound having a melting point of 80 ° C. or higher is preferably used from the viewpoint of heat resistance, moisture resistance, flame retardancy, chemical resistance, and the like. Such phosphazene compounds can be used alone or in admixture of two or more.

  The content of the phosphazene compound as the component (D) is preferably 1 part by mass or more and 50 parts by mass or less, particularly 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the resin component soluble in the diluted alkali solution of the component (A). Part or less is preferred. When the content of the phosphazene compound as the component (D) is less than 1 part by mass, the flame retardancy of the cured product of the resin composition may be insufficient, and when it exceeds 50 parts by mass, the cured product of the resin composition The adhesiveness of the resin is lowered, and cracks are easily generated.

  The photopolymerization initiator of component (E) is an active radical generator that generates active radicals upon irradiation with active energy rays such as ultraviolet rays, and known and conventional ones can be used.

  Examples of the active radical generator include benzoins such as benzoin, benzoin methyl ether, and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1- Acetophenones such as dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, N, N-dimethylaminoacetophenone; 2-methyl Anthraquinones such as anthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 1-chloroanthraquinone, 2-amylanthraquinone, 2-aminoanthraquinone; 2,4-dimethylthioxanthone, 2, -Thioxanthones such as diethylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, 2,4-diisopropylthioxanthone; ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal; benzophenone, methylbenzophenone, 4,4'-dichlorobenzophenone, Benzophenones such as 4,4′-bisdiethylaminobenzophenone, Michler's ketone, 4-benzoyl-4′-methyldiphenyl sulfide; A combination of the above can be used.

  When a plurality of photopolymerization initiators are used in combination, for example, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (Irgacure 907, manufactured by Ciba-Geigy) And a combination of 2,4-diethylthioxanthone (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.), 2-isopropylthioxanthone, or 4-benzoyl-4′-methyldiphenyl sulfide.

  (E) As for content of the photoinitiator of a component, 1 mass part or more and 50 mass parts or less are preferable with respect to 100 mass parts of resin components soluble in the dilute alkali solution of (A) component. When the content of the photopolymerization initiator as the component (E) is less than 1 part by mass, the resin composition may not be sufficiently insolubilized by irradiation with active energy rays. When the content exceeds 50 parts by mass, the resin composition The adhesion of the cured product is reduced, and cracks and the like are likely to occur.

  Moreover, a photosensitizer can be contained in the resin composition as needed. Examples of the photosensitizer include tertiary amines such as N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, and triethanolamine. These may be used alone or in combination of two or more.

  Examples of the diluent for component (F) include organic solvents and photopolymerizable monomers. The photopolymerizable monomer dilutes a resin component soluble in the dilute alkali solution of the component (A), adjusts the viscosity to a state where it can be easily applied, and enhances photopolymerizability. In addition, the organic solvent is formed by diluting the resin component soluble in the dilute alkali solution of the component (A), adjusting the viscosity to a state where it can be easily applied, and applying and drying to form a film. Therefore, either a contact method or a non-contact exposure method in which the photomask is brought into contact with the coating film is selected according to the type of diluent used.

  Examples of the organic solvent include ketones such as ethyl methyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, di Glycol ethers such as propylene glycol monoethyl ether, dipropylene glycol diethyl ether and triethylene gericol monoethyl ether; esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate and carbitol acetate; ethanol, propanol, ethylene glycol, propylene Alcohols such as glycol; aliphatic hydrocarbons such as octane and decane; petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtho It may be mentioned petroleum-based solvents and the like.

  Examples of the photopolymerizable monomer include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; monoglycols such as ethylene glycol, methoxytetraethylene glycol, and polyethylene glycol. Or di (meth) acrylates; (meth) acrylamides such as N, N-dimethyl (meth) acrylamide and N-methylol (meth) acrylamide; aminoalkyls such as N, N-dimethylaminoethyl (meth) acrylate (meta) Acrylates; polyhydric alcohols such as hexanediol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, tris-hydroxyethyl isocyanurate; Polyhydric (meth) acrylates of ethylene oxide or propylene oxide adducts of polyhydric alcohols; Polyvalents of ethylene oxide or propylene oxide adducts of phenols such as phenoxyethyl (meth) acrylate and polyethoxydi (meth) acrylate of bisphenol A ( (Meth) acrylates; glycidyl ether (meth) acrylates such as glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl isocyanurate; ε-caprolactone modified (meta) such as caprolactone-modified tris (acryloxyethyl) isocyanurate ) Acrylates; melamine (meth) acrylate and the like. Such diluents can be used alone or in admixture of two.

  The content of the diluent of component (F) is not particularly limited and can be appropriately selected depending on the coating method of the resin composition. For example, it is soluble in the dilute alkaline solution of component (A). 1 to 100 parts by mass is preferable with respect to 100 parts by mass of the resin component, and particularly 10 to 80 parts by mass is preferable. When the content of the diluent of component (F) is less than 1 part by mass or exceeds 100 parts by mass, both are not preferable because the applicability of the resin composition is not excellent.

  In this invention, you may contain organic phosphorus compounds other than these with the (meth) acryl group containing phosphorus compound of (C) component, and the phosphazene compound of (D) component. By including such an organic phosphorus compound, it is preferable in that sufficient flame retardancy can be obtained even when the amount of the flame retardant added is reduced. Such an organic phosphorus compound may be an organic phosphorus compound generally used as a flame retardant for a photosensitive thermosetting resin composition, and examples thereof include organic phosphorus compounds such as melamine phosphate compounds and phosphinates. be able to.

  Examples of the melamine phosphate compound include a melamine phosphate compound represented by the following general formula [4]. This is a salt in which phosphoric acid and melamine exist.

（但し、式中、ｑは１以上１０以下の整数である。）

(In the formula, q is an integer of 1 to 10, inclusive.)

  Examples of the phosphinic acid salts include phosphinic acid salts represented by the following general formulas [5] and [6].

（但し、式中、Ｒ^８、Ｒ^９は、同一または互いに異なって、直鎖状若しくは分枝鎖状の炭素数１以上６以下のアルキル基、または炭素数６以上１２以下のアリール基であり、Ｍ^ｓ＋は、イオン化したＭｇ、Ｃａ、Ａｌ、Ｓｂ、Ｓｎ、Ｇｅ、Ｔｉ、Ｚｎ、Ｆｅ、Ｚｒ、Ｃｅ、Ｂｉ、Ｓｒ、Ｍｎ、Ｌｉ、Ｎａ、およびＫ、ならびにプロトン化された窒素塩基から選ばれる少なくとも一つのイオンであり、ｒ、ｓ、ｔはそれぞれ１以上４以下であり、かつｒ＝ｓ×ｔを満たすものである。）

（但し、式中、Ｒ^１０、Ｒ^１１は、同一または互いに異なって、直鎖状若しくは分枝鎖状の炭素数１以上６以下のアルキル基、または炭素数６以上１２以下のアリール基であり、Ｒ^１２は、直鎖状若しくは分枝鎖状の炭素数１以上１０以下のアルキレン基、炭素数６以上１０以下のアリーレン基、炭素数６以上１０以下のアルキルアリーレン基、または炭素数６以上１０以下のアリールアルキレン基であり、Ｍ^ｖ＋は、イオン化したＭｇ、Ｃａ、Ａ１、Ｓｂ、Ｓｎ、Ｇｅ、Ｔｉ、Ｚｎ、Ｆｅ、Ｚｒ、Ｃｅ、Ｂｉ、Ｓｒ、Ｍｎ、Ｌｉ、Ｎａ、およびＫ、ならびにプロトン化された窒素塩基から選ばれる少なくとも一つのイオンであり、ｕ、ｖ、Ｗはそれぞれ１以上４以下であり、かつ２×ｕ＝ｖ×ｗを満たすものである。）。

(In the formula, R ⁸ and R ⁹ are the same or different from each other, and are linear or branched alkyl groups having 1 to 6 carbon atoms, or aryl groups having 6 to 12 carbon atoms. , M ^{s +} from ionized Mg, Ca, Al, Sb, Sn, Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, and K, and a protonated nitrogen base (At least one selected ion, r, s, and t are 1 or more and 4 or less, respectively, and r = s × t is satisfied.)

(In the formula, R ¹⁰ and R ¹¹ are the same or different from each other, and are linear or branched alkyl groups having 1 to 6 carbon atoms, or aryl groups having 6 to 12 carbon atoms. , R ¹² represents a linear or branched alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, an alkylarylene group having 6 to 10 carbon atoms, or 6 or more carbon atoms. 10 or less arylalkylene groups, and ^{Mv +} is ionized Mg, Ca, A1, Sb, Sn, Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, and K, And at least one ion selected from protonated nitrogen bases, u, v and W are each 1 or more and 4 or less and satisfy 2 × u = v × w.

Examples of protonated nitrogen bases in M ^{s +} and M ^{v +} in the general formulas [5] and [6] include protonated nitrogen bases such as ammonia, melamine, and triethanolamine. In particular, an ammonium ion (NH ₄ ⁺ ) is preferable.

In addition, examples of the alkyl group represented by R ^{8 to} R ¹¹ in the general formulas [5] and [6] include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tertiary butyl group, and an n- group. A pentyl group is mentioned, As an aryl group, a phenyl group is mentioned, for example. Examples of the alkylene group for R ¹² include methylene group, ethylene group, n-propylene group, isopropylene group, n-butylene group, tertiary butylene group, n-pentylene group, n-octylene group, and n-dodecylene group. Examples of the arylene group include a phenylene group and a naphthylene group. Examples of the alkylarylene group include a methylphenylene group, an ethylphenylene group, a tertiary butylphenylene group, a methylnaphthylene group, an ethylnaphthylene group, a Examples include an arylalkylene group such as a phenylmethylene group, a phenylethylene group, a phenylpropylene group, and a phenylbutylene group.

Moreover, as another organic phosphorus compound, phosphinoyl propionic acid represented by the following general formula [7] can be mentioned.

  The content of the other organic phosphorus compound is preferably 1 part by mass or more and 50 parts by mass or less, particularly 1 part by mass or more and 30 parts by mass or less, with respect to 100 parts by mass of the resin component soluble in the dilute alkali solution of component (A). Is preferred. Other organic phosphorus compounds may be used alone or in combination of two or more.

  For the purpose of improving adhesion, hardness, etc., the resin composition has barium sulfate, barium titanate, silicon oxide powder, finely divided silicon oxide, amorphous silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, A publicly known inorganic filler such as aluminum hydroxide and mica powder can be contained as required. When the inorganic filler is contained, the content thereof is preferably 60% by mass or less, particularly preferably 5% by mass or more and 40% by mass or less, with respect to the entire resin composition.

  Further, the resin composition includes phthalocyanine / blue, phthalocyanine / green, iodine / green, disazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black, and other known and commonly used colorants, hydroquinone, hydroquinone monomethyl ether, t- Known and conventional polymerization inhibitors such as butylcatechol, pyrogallol and phenothiazine, known and conventional thickeners such as asbestos, olben, benton and montmorillonite, defoamers such as silicone, fluorine and polymer, leveling agents, imidazole Known and commonly used additives such as silane coupling agents such as those based on thiols, thiazoles and triazoles can be contained as required.

  In addition, copolymers of ethylenically unsaturated compounds such as acrylic acid esters, known conventional binder resins such as polyester resins synthesized from polyhydric alcohols and polybasic acid compounds, polyester (meth) acrylates, Photopolymerizable oligomers such as polyurethane (meth) acrylate and epoxy (meth) acrylate can be used as long as they do not affect various properties as a solder resist.

  The resin composition of the present invention has the above-mentioned components (A) to (F) as essential components, and other components as described above are added as necessary and within the limits not departing from the gist of the present invention. -It can manufacture by mix | blending after mixing uniformly with a three roll mill etc.

  The resin composition thus produced is applied on a flexible copper-clad laminate having a wiring pattern formed thereon by a method such as a screen printing method, a curtain coating method, a spray coating method, or a roll coating method. It heat-processes at the temperature of 100 degreeC, and the organic solvent is volatilized and dried and it is set as a coating film. Thereafter, the resist film is selectively exposed by irradiating active energy rays such as ultraviolet rays through a photomask having a predetermined exposure pattern formed on the coating film, and developing the unexposed portion with a dilute alkaline aqueous solution to form a resist pattern. And by heating this resist pattern to the temperature of 140-180 degreeC, a thermosetting component can be hardened and a resist film can be obtained.

  Examples of the alkaline aqueous solution used for development include potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines and the like. Examples of the irradiation light source used for exposure include a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a xenon lamp, and a metal halide lamp.

  The flexible printed wiring board of the present invention has a polyimide layer and a copper layer laminated on at least one main surface of the polyimide layer, and the resin composition of the present invention described above on at least one main surface. It has the resin layer which consists of. The polyimide layer and the copper layer constituting the flexible printed wiring board may be directly laminated, or may be laminated via an adhesive layer. A wiring pattern can be formed on the copper layer portion as necessary, and drilling through hole plating can be performed.

  For example, such a flexible printed wiring board covers a wiring pattern as described above after a wiring pattern is formed on the copper foil portion of a flexible copper-clad laminate in which a copper foil is bonded to one or both sides of a polyimide film. Then, the resin composition of the present invention is applied, exposed and developed, and thermally cured to form a resin layer, which can be easily produced.

  In addition, the flexible printed wiring board of the present invention is formed by heating and press-molding by superposing a reinforcing plate via a thermosetting resin composition or the like as an adhesive, thereby providing a new flexible printed wiring board of the present invention. A flexible printed wiring board with a reinforcing plate can be used. Furthermore, in the flexible printed wiring board of the present invention, another flexible printed wiring board is overlaid through a thermosetting resin composition as an adhesive, and heat-press molding is performed, and if necessary, through holes are formed. By performing through-hole plating and forming a circuit, a multilayer flexible printed wiring board as a new flexible printed wiring board of the present invention can be obtained.

  Hereinafter, the present invention will be described in detail with reference to examples.

  First, manufacture of the photosensitive thermosetting resin composition of an Example and a comparative example is demonstrated. In addition, the compounding quantity of each photosensitive thermosetting resin composition is as showing in Table 1.

(Synthesis of phosphorus-containing epoxy resin)
The phosphorus containing epoxy resin used for preparation of the resin composition of a comparative example was synthesize | combined as follows. That is, bisphenol F type diglycidyl ether (EPICLON830, manufactured by Dainippon Ink & Chemicals, Inc., epoxy equivalent 185 g / eq) 453.5 g as an epoxy resin, and 10- (2,5-dihydroxyphenyl) -10H-9 as a phosphorus compound -Oxa-10-phosphaphenanthrene-10-oxide (HCA-HQ, manufactured by Sanko Chemical Co., Ltd., molecular weight 324.3) 104.5 g, tetramethylammonium chloride 0.5 g as an aqueous solution as a reaction catalyst, in ethanol The phosphorus compound and the epoxy resin were reacted at an equivalent ratio of 0.140 / 1 at a temperature of 100 to 180 ° C. for 5 hours to obtain a phosphorus-containing epoxy resin having an epoxy equivalent of 300 g / eq and a phosphorus content of 2.0%.

Example 1
44 parts by mass of an epoxy acrylate compound (Kayarad ZFRl122, manufactured by Nippon Kayaku Co., Ltd.) as a resin component having a (meth) acryloyl group and a carboxyl group in one molecule and soluble in a dilute alkaline solution, and photopolymerizable as a diluent 6.5 parts by weight of monomer (Kayarad DPHA, Nippon Kayaku Co., Ltd.), 4.5 parts by weight of photopolymerization initiator 1 (Darocur TPO, manufactured by Ciba Geigy) as a photopolymerization initiator and photopolymerization initiator 2 (Irgacure) 184, manufactured by Ciba-Geigy) 2.0 parts by mass, (meth) acrylic group-containing phosphorus compound (meth) acrylic group-containing phosphorus compound represented by the chemical formula [1a] 13 parts by mass, and thermosetting component biphenyl type epoxy resin (Epicoat YL6121H, manufactured by Japan Epoxy Resin Co., Ltd.) 13 mass capital, imidazole polymerization catalyst (2E4M as curing agent) , Shikoku Kasei Kogyo Co., Ltd.) 1.3 parts by mass, melamine 1.3 parts by mass, barium sulfate (B-30, Sakai Chemical Industry Co., Ltd.) 6.5 parts by mass, phthalocyanine green 1.3 parts by mass, fine silica (Aerosil R972, manufactured by Nippon Aerosil Co., Ltd.) 3.3 parts by mass, and 3.3 parts by mass of a phenoxyphosphazene oligomer (melting point: 110 ° C.) as a phosphazene compound were kneaded with a three-roll mill to obtain a resin composition (photosensitive A thermosetting resin composition) was produced.

(Example 2)
In the production of the resin composition of Example 1, the (meth) acryl group-containing phosphorus compound is represented by the general formula [1b] instead of the (meth) acryl group-containing phosphorus compound represented by the general formula [1a] (meth) ) Manufactured using an acrylic group-containing phosphorus compound.

(Example 3)
In the production of the resin composition of Example 2, instead of using only the phenoxyphosphazene oligomer (melting point 110 ° C.) as the phosphazene compound, 2.3 parts by mass of the phenoxyphosphazene oligomer (melting point 110 ° C.) and cyanophenoxyphosphazene (melting point 120 ° C.) It manufactured using 1.0 mass part.

(Draft Example 4)
In the production of the resin composition of Example 1, instead of using only the (meth) acrylic group-containing phosphorus compound represented by the general formula [1a] as the (meth) acrylic group-containing phosphorus compound, it is represented by the general formula [1a]. It manufactured using 6.5 mass parts of (meth) acryl group-containing phosphorus compounds and 6.5 mass parts of (meth) acryl group-containing phosphorus compounds represented by the general formula [1b].

(Example 5)
51 parts by mass of an epoxy acrylate compound (Kayarad ZFRl122, manufactured by Nippon Kayaku Co., Ltd.) as a resin component that has a (meth) acryloyl group and a carboxyl group in one molecule and is soluble in a dilute alkaline solution, and is photopolymerizable as a diluent. Monomer (Kayarad DPHA, Nippon Kayaku Co., Ltd.) 12.5 parts by mass, photopolymerization initiator 1 (Darocur TPO, Ciba Geigy) 4.5 parts by mass and photopolymerization initiator 2 (Irgacure) 184, manufactured by Ciba-Geigy Co., Ltd.) 2.0 parts by mass, 6.5 parts by mass of (meth) acrylic group-containing phosphorus compound represented by chemical formula [1a] as a (meth) acrylic group-containing phosphorus compound, and biphenyl type as a thermosetting component 6.5 parts by mass of an epoxy resin (Epicoat YL6121H, manufactured by Japan Epoxy Resin Co., Ltd.), an imidazole polymerization catalyst (2 4MZ, manufactured by Shikoku Kasei Kogyo Co., Ltd.) 1.3 parts by mass, 1.3 parts by mass of melamine, 6.5 parts by mass of barium sulfate (B-30, manufactured by Sakai Chemical Industry Co., Ltd.), 1.3 parts by mass of phthalocyanine green, fine powder A resin composition was produced by blending 3.3 parts by mass of silica (Aerosil R972, manufactured by Nippon Aerosil Co., Ltd.) and 3.3 parts by mass of a phenoxyphosphazene oligomer (melting point: 110 ° C.) as a phosphazene compound and kneading in a three-roll mill. .

(Comparative Example 1)
51 parts by mass of an epoxy acrylate compound (Kayarad ZPRl122, manufactured by Nippon Kayaku Co., Ltd.) as a resin component that has a (meth) acryloyl group and a carboxyl group in one molecule and is soluble in a dilute alkaline solution, and is photopolymerizable as a diluent. Monomer (Kayarad DPHA, Nippon Kayaku Co., Ltd.) 12.5 parts by mass, photopolymerization initiator 1 (Darocur TPO, Ciba Geigy) 4.5 parts by mass and photopolymerization initiator 2 (Irgacure) 184, manufactured by Ciba-Geigy) 2.0 parts by mass, 13 parts by mass of a brominated epoxy resin (Epicron 1121, manufactured by Dainippon Ink) as a thermosetting component, and an imidazole-based polymerization catalyst (2E4MZ, Shikoku Kasei Kogyo Co., Ltd.) as a curing agent 1.3 parts by mass and 1.3 parts by mass of melamine, 6.5 parts by mass of barium sulfate (B-30, Sakai Chemical Industry Co., Ltd.), phthalocyanine 1.3 parts by weight of lean, 3.3 parts by weight of fine silica (Aerosil R972, manufactured by Nippon Aerosil Co., Ltd.), and 3.3 parts by weight of phenoxyphosphazene oligomer (melting point 110 ° C.) as a phosphazene compound are mixed and kneaded by a three roll mill. Thus, a resin composition was produced.

(Comparative Example 2)
In the production of the resin composition of Comparative Example 1, production was carried out using the above-described phosphorus-containing epoxy resin instead of using the brominated epoxy resin.

(Comparative Example 3)
In the production of the resin composition of Comparative Example 2, the compounding amount of the phosphorus-containing epoxy resin was changed from 13 parts by mass to 16.3 parts by mass, and the resin composition was produced without compounding the phosphazene compound.

(Comparative Example 4)
53.3 parts by mass of an epoxy acrylate compound (Kayarad ZFR1122, manufactured by Nippon Kayaku Co., Ltd.) as a resin component that has a (meth) acryloyl group and a carboxyl group in one molecule and is soluble in a dilute alkaline solution, and light as a diluent 13.5 parts by mass of a polymerizable monomer (Kayarad DPHA, manufactured by Nippon Kayaku Co., Ltd.), 4.5 parts by mass of a photopolymerization initiator 1 (Darocur TPO, manufactured by Ciba Geigy) as a photopolymerization initiator and a photopolymerization initiator 2 (Irgacure 184, manufactured by Ciba-Geigy) 2.0 parts by mass, imidazole-based polymerization catalyst (2E4MZ, manufactured by Shikoku Kasei Kogyo Co., Ltd.) 1.3 parts by mass as a curing agent, 1.3 parts by mass of melamine, barium sulfate (B -30, manufactured by Sakai Chemical Industry Co., Ltd.) 6.5 parts by mass, 1.3 parts by mass of phthalocyanine green, fine silica (Aerosil R972, manufactured by Nippon Aerosil Co., Ltd.) .3 parts by weight, phenoxyphosphazene oligomer (melting point 110 ° C.) was blended 13.0 parts by weight phosphazene compound, a resin composition was prepared by kneading in a three-roll mill.

  Next, the resin composition of an Example and a comparative example is 20-30 micrometers thick by screen printing using a 150 mesh polyester screen to the copper clad polyimide film board (copper thickness 18 micrometers / polyimide film thickness 25 micrometers) by which pattern formation was carried out. The whole surface was applied so that the film was dried and dried for 30 minutes by a hot air dryer at 80 ° C. to form a coating film.

Then, the negative film of the resist pattern was made to contact a coating film, and it irradiated with the ultraviolet-ray using the ultraviolet irradiation exposure apparatus (exposure amount 400mJ / cm < ² >). And it developed with 1 kgf / cm < ² > for 1 minute spray using 1 mass% concentration sodium carbonate aqueous solution, and the unexposed part was dissolved and removed. Furthermore, the cured film was obtained by thermosetting under the conditions of 150 ° C. × 60 minutes.

  About the obtained cured film, flame retardance, insulation resistance, combustion gas analysis, adhesion, pencil hardness, resolution, solder heat resistance, chemical resistance, folding resistance are measured based on the following methods and standards. evaluated. The results are shown in Table 1.

[Flame retardance test]
The test was conducted according to the UL94 flame retardant test.
[Insulation resistance]
The test was conducted according to IEC-PB112.
[Combustion gas analysis]
The sample was burned in air at 750 ° C. for 10 minutes, and the gas generated at that time was absorbed in water as an absorbing solution and analyzed by ion chromatography, and the hydrogen bromide concentration in 100 g of the generated gas was calculated.
[Adhesion]
A test piece in which the cured film surface of the test substrate was cross-cut to 100 mm in accordance with JIS D 0202 was subjected to a peeling test using a cellophane tape to examine the number of peeled pieces.
[Pencil hardness]
It measured according to JISK5400.
[Resolution]
Using an electron microscope, the opening state when alkali development on the substrate was confirmed.
[Solder heat resistance]
A test piece was floated on a solder bath at 260 ° C. for 1 minute to observe the presence or absence of swelling, and evaluation was performed according to the following criteria. ◎… No swelling, ○… Swelling in part, ×… Swelling in whole [chemical resistance]
The test pieces were immersed in 10% sulfuric acid, 10% aqueous sodium hydroxide, isopropyl alcohol, methanol, and methyl ethyl ketone for 30 minutes at room temperature to confirm the appearance, and evaluated according to the following criteria. ○: No change in appearance, ×: Change in appearance [Folding resistance]
According to JIS C 6471, the number of times until a crack was generated in the cured film was measured at R = 0.8 mm and a load of 4.9 N using an MlT folding resistance tester.

  As is apparent from Table 1, the resin compositions of the examples are excellent in flame retardancy and suppressed generation of hydrogen bromide, and have adhesion, hardness, resolution, solder heat resistance, chemical resistance. It can be seen that the resin composition has sufficient characteristics with respect to the property and folding resistance, and is superior to a conventional resin composition using a brominated epoxy resin or a phosphorus-containing epoxy resin.

Claims (4)

(A) a resin component having a (meth) acryloyl group and a carboxyl group in one molecule and soluble in a dilute alkali solution;
(B) a thermosetting component having an epoxy group,
(C) a (meth) acryloyl group-containing phosphorus compound represented by the following general formula [1],

(In the formula, R ¹ represents hydrogen or a methyl group.)
(D) a phosphazene compound,
A photosensitive thermosetting resin composition comprising (E) a photopolymerization initiator and (F) a diluent. The photosensitive thermosetting resin composition according to claim 1, wherein the (D) phosphazene compound contains a phosphazene oligomer represented by the following general formula [2] or [3].

^(Wherein, R 2, ^{R 3} are the same or different from each other, a hydrogen atom, an amino group or a monovalent organic group having 1 to 12 carbon atoms containing no ^halogen,, R 4, ^{R 5} Are the same or different from each other, and each represents a hydrogen atom, a hydroxyl group, or a monovalent organic group having 1 to 12 carbon atoms, and m represents an integer of 3 to 10.

(In the formula, R ⁶ and R ⁷ are the same or different from each other, and each represents a hydrogen atom, an amino group, or a monovalent organic group having 1 to 12 carbon atoms that does not contain halogen, and n is 3 or more and 10 The following integers are shown.)   (B) 1 part by mass or more and 100 parts by mass or less of the (C) (meth) acryloyl group, with respect to 100 parts by mass of the resin component soluble in the (A) dilute alkali solution. 1 part by weight or more and 50 parts by weight or less of the phosphorus compound, 1 part by weight or more and 50 parts by weight or less of the (D) phosphazene compound, 1 part by weight or more and 50 parts by weight or less of the (E) photopolymerization initiator, and the diluent (F) 1 to 100 parts by mass of the photosensitive thermosetting resin composition according to claim 1 or 2. A flexible printed wiring board having a polyimide layer and a copper layer laminated on at least one main surface of the polyimide layer,
A flexible printed wiring board comprising a resin layer comprising the photosensitive thermosetting resin composition according to any one of claims 1 to 3 on at least one main surface.