JP2005236273A - Flame-retardant composition for solder resist, hardening method and use thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flame-retardant composition having flame retardancy and flexibility both as well as being excellent in solder heat resistance, moisture proof, and reliability in a high temperature, which is therefore suitable for use as a cover lay film for an FPC, solder resist, etc. <P>SOLUTION: This invention comprises following items: a flame-retardant composition including polyester resin (A) which contains a bromine atom in a molecule; a hardened material of the composition for solder resist; an ink containing the composition and a colorant; a hardening method of the composition; an insulating protection film and an interlayer insulating film composed of the composition; and printed circuit boards including the films. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a flame retardant composition for solder resist. More specifically, the present invention relates to a flame retardant composition for a solder resist used for manufacturing a printed wiring board, particularly a flexible printed wiring board, and a curing method and use thereof.

In the production of a printed wiring board, various substrate protection means such as a resist used during etching and a solder resist used in a soldering process have been conventionally required. Solder for protecting irrelevant wiring in the soldering process for component mounting even in the manufacturing process of film-like printed wiring boards (flexible printed wiring boards; hereinafter abbreviated as FPC) used for small equipment A resist is required.
As a protection means for such a substrate, conventionally, a cover lay in which a polyimide film punched into a predetermined mold is laminated has been used. This coverlay also serves as a protective film for the wiring after soldering, and is required to have heat resistance and insulation during soldering and flexibility so that cracks do not occur when the board is assembled. Furthermore, the FPC used for devices other than battery-driven devices also requires flame retardancy.

Coverlays formed by punching a polyimide film satisfy the above-mentioned requirements and are currently most frequently used. However, an expensive mold is required for punching, and the punched film is manually positioned. Since they are bonded together, there is a problem that the cost is further increased and it is difficult to form a fine pattern.
As a method for solving these problems, a method has been proposed in which a photosensitive resin composition is applied in a liquid form on a substrate, or a film is pasted. According to this method, after forming a coating film on a substrate, a fine pattern coverlay can be easily formed by exposure, development, and heating by photographic technology. Has been.

  However, none of the conventional photosensitive resin compositions satisfy all these characteristics required for FPC. For example, a photosensitive resin composition comprising a prepolymer obtained by addition reaction of a polybasic acid anhydride to a novolak-type epoxy vinyl ester resin, a photopolymerization initiator, a diluent, and an epoxy compound has been proposed (Japanese Patent Publication No. 1-54390). Although this resin composition has good heat resistance and insulation, it is not flexible and unsuitable for FPC. In addition, a binder system comprising a low molecular weight copolymer, which is a reaction product of a copolymer formed from an ethylenically unsaturated dicarboxylic acid anhydride and an ethylenically unsaturated comonomer, and an amine, and a carboxylic acid-containing high molecular weight copolymer is added to an acrylic resin. A photosensitive resin composition containing a fluorinated urethane monomer component, a photoinitiator and a block polyisocyanate crosslinking agent has been proposed (Japanese Patent Laid-Open No. 7-278492; Patent Document 2), but this resin composition has flame retardancy. There was a problem that the use was limited.

  As a method for imparting flame retardancy to the photosensitive resin composition, a conventional flame retardant such as a brominated epoxy resin or a flame retardant system in combination with a flame retardant aid such as antimony trioxide is used. There was a method (JP-A-9-325490; Patent Document 3, JP-A-11-242331; Patent Document 4). However, these flame retardant systems may be inferior in reliability in a high temperature environment, and when using an antimony compound, it is necessary to consider environmental issues regarding the waste treatment of the resin. Furthermore, the brominated epoxy resin has a large problem that flexibility is impaired and thermosetting property is lowered when an amount capable of obtaining a sufficient flame retardancy is added.

  In this way, it is easy to obtain a resist that has both high flame resistance and flexibility enough to meet the standards of the UL standard (Underwriters Laboratories requirements), and excellent in soldering heat resistance, moisture resistance, high temperature reliability, etc. Instead, further improvements were desired.

Japanese Patent Publication No. 1-54390 JP 7-278492 A JP-A-9-325490 JP-A-11-242331

  The present invention provides a curable flame retardant composition for resist, particularly a solder resist for FPC, which has both a high level of flame retardancy and flexibility, and is excellent in solder heat resistance, moisture resistance, and high temperature reliability. It aims at providing the flame retardant composition for solder resists which can be used suitably.

  As a result of intensive studies, the present inventors have found that the above problem can be solved by blending a specific polyester resin containing a bromine atom in the molecule, and have completed the present invention.

（式中、Ｘ¹、Ｘ²、Ｘ³及びＸ⁴のうち、少なくとも２個は臭素原子を表し、残りは水素原子を表し、Ｒ¹及びＲ²はそれぞれ２価の有機基を表す。）で示される化合物及び／またはジブロモネオペンチルグリコールである前記３記載のソルダーレジスト用難燃組成物。
５．前記式（１）で示される化合物（ａ）が、下記式（２）

で示される化合物である前記４記載のソルダーレジスト用難燃組成物。
６．分子中に２個のエポキシ基を有する化合物（ｃ）が、式（３）

（式中、Ｒ³は、炭素数１２〜３０の、置換基を有してもよいアルキレン基または置換基を有してよいアルケニレン基を表す。）
で示される前記３記載のソルダーレジスト用難燃組成物。
７．Ｒ³が、７，１１−オクタデカジエニレン基または７，１２−ジメチル−７，１１−オクタデカジエニレン基である前記６記載のソルダーレジスト用難燃組成物。
８．前記１乃至７のいずれか１項に記載のソルダーレジスト用難燃組成物の硬化物。
９．前記１乃至７のいずれか１項に記載のソルダーレジスト用難燃組成物と着色剤とを含有することを特徴とするインク。
１０．前記１乃至７のいずれか１項に記載のレジスト用硬化性難燃組成物を基板に１０〜１００μｍの厚みで塗布した後、１００〜２００℃の温度範囲で１０〜６０分熱処理して硬化させることを特徴としたソルダーレジスト用難燃組成物の硬化方法。
１１．前記１乃至７のいずれか１項に記載のソルダーレジスト用難燃組成物からなることを特徴とする絶縁保護皮膜。
１２．前記１乃至７のいずれか１項に記載のソルダーレジスト用難燃組成物からなることを特徴とする層間絶縁膜。
１３．前記１１記載の絶縁保護皮膜を有することを特徴とするプリント配線板。
１４．前記１２記載の層間絶縁膜を有することを特徴とするプリント配線板。 That is, this invention relates to the flame retardant composition for solder resists shown in the following 1-14, its hardening method, and a use.
1. A flame retardant composition for a solder resist, comprising a polyester resin (A) containing a bromine atom in the molecule.
2. 2. The flame retardant composition for a solder resist according to 1 above, wherein the content of the polyester resin (A) containing a bromine atom in the molecule in the resin component is 10 to 70% by mass.
3. The polyester resin (A) containing a bromine atom in the molecule contains a compound (a) having two or more bromine atoms and two or more hydroxyl groups in the molecule, a compound (b) having an acid anhydride group, and a molecule 3. The flame retardant composition for a solder resist according to the above 1 or 2, which is a resin obtained by reacting a compound (c) having two epoxy groups.
4). The compound (a) having two or more bromine atoms and two or more hydroxyl groups in the molecule is represented by the following formula (1):

(In the formula, at least two of X ¹ , X ² , X ³ and X ⁴ represent bromine atoms, the rest represent hydrogen atoms, and R ¹ and R ² each represent a divalent organic group.) 4. The flame retardant composition for solder resists according to 3 above, which is a compound represented by the formula (1) and / or dibromoneopentyl glycol.
5). The compound (a) represented by the formula (1) is represented by the following formula (2)

5. The flame retardant composition for a solder resist according to the above 4, which is a compound represented by
6). The compound (c) having two epoxy groups in the molecule is represented by the formula (3)

(In the formula, R ³ represents an alkylene group having 12 to 30 carbon atoms which may have a substituent or an alkenylene group which may have a substituent.)
4. The flame retardant composition for solder resists according to 3 above,
7). 7. The flame retardant composition for a solder resist according to 6, wherein R ³ is a 7,11-octadecadienylene group or a 7,12-dimethyl-7,11-octadecadienylene group.
8). Hardened | cured material of the flame retardant composition for soldering resists of any one of said 1 thru | or 7.
9. 8. An ink comprising the flame retardant composition for a solder resist according to any one of 1 to 7 and a colorant.
10. 8. The resist curable flame retardant composition according to any one of 1 to 7 is applied to a substrate with a thickness of 10 to 100 μm, and then cured by heat treatment at a temperature range of 100 to 200 ° C. for 10 to 60 minutes. A method for curing a flame retardant composition for a solder resist, characterized in that:
11. An insulating protective film comprising the flame retardant composition for a solder resist according to any one of 1 to 7 above.
12 8. An interlayer insulating film comprising the flame retardant composition for a solder resist according to any one of 1 to 7 above.
13. A printed wiring board comprising the insulating protective film according to 11 above.
14 13. A printed wiring board comprising the interlayer insulating film as described in 12 above.

  The flame retardant composition for solder resists of the present invention can form a protective film having excellent flame retardancy and flexibility and solder heat resistance, and is particularly suitable for forming FPC coverlays, solder resists and the like. Can do.

The present invention is described in detail below.
1. Polyester resin having bromine atom in molecule (A)
The polyester resin (A) containing a bromine atom in the molecule used in the flame retardant composition for a solder resist of the present invention includes thermosetting having a bromine atom, an ester bond and a long-chain alkylene group or a long-chain alkenylene group in the molecule. Resin.
Specifically, for example, a compound (a) having two or more bromine atoms and two or more hydroxyl groups in the molecule, a compound (b) having an acid anhydride group, and two or more epoxy groups in the molecule. It can be obtained by reacting the compound (c).

（Ｘ¹、Ｘ²、Ｘ³及びＸ⁴のうち、少なくとも２個は臭素原子を表し、残りは水素原子を表し、Ｒ¹、Ｒ²はそれぞれ２価の有機基を表す。）
で示される化合物及びジブロモネオペンチルグリコールが挙げられる。 1-1. Compound having two or more bromine atoms and two or more hydroxyl groups in the molecule (a)
The compound (a) having two or more bromine atoms and two or more hydroxyl groups in the molecule is preferably represented by the formula (1)

(At least two of X ¹ , X ² , X ³ and X ⁴ represent bromine atoms, the rest represent hydrogen atoms, and R ¹ and R ² each represent a divalent organic group.)
And a compound represented by formula (2) and dibromoneopentyl glycol.

The compound represented by the formula (1) can be obtained, for example, by addition condensation of brominated phthalic anhydride or brominated phthalic acid and a compound having two hydroxyl groups in one molecule.
In the formula (1), R ¹ and R ² represent a divalent organic group, which is a portion where one of two hydroxyl groups in one molecule is dehydroxylated. Here, R ¹ and R ² may be the same or different. As preferred R ¹ and R ² , those having an alkylene group are preferred in the present invention where flexibility is required. Specific examples include ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, methylethylene, 1-methylpropylene, and 2,2-dimethylpropylene. , And those having an oxygen atom in their base chain.

  Moreover, as a compound having two hydroxyl groups in one molecule, which is a raw material for the compound of formula (1), ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,12-dodecanediol, neopentyl glycol, diethylene glycol, triethylene Examples include glycol, dipropylene glycol, and tripropylene glycol.

Specific examples of brominated phthalic anhydride that is a raw material for the compound of formula (1) include tetrabromophthalic anhydride, and examples of brominated phthalic acid include tetrabromophthalic acid.
The compound represented by the formula (1) includes brominated phthalic anhydride, a compound having two hydroxyl groups in one molecule, propylene oxide, as described in International Publication No. 94/10123. And those obtained by reaction with alkylene oxides such as ethylene oxide.

で示される化合物が挙げることができる。 Among the compounds represented by formula (1), those having a more preferred structure from the viewpoints of flexibility and flame retardancy are represented by formula (2)

The compound shown by these can be mentioned.

1-2. Compound (b) having an acid anhydride group
The compound (b) having an acid anhydride group is used for molecular chain extension of the polyester resin (A) containing a bromine atom used in the present invention. Specific examples of such compounds include succinic anhydride, maleic anhydride, itaconic anhydride, citraconic anhydride, dodecenyl succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride. , Methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, chlorendic anhydride, etc., but succinic anhydride, Itaconic acid is preferred.

（Ｒ³は炭素数が１２〜３０の置換基を有しても良いアルキレン基、または置換基を有しても良いアルケニレン基を表す。）
で示される化合物が特に好ましい。 1-3. Compound (c) having two epoxy groups in the molecule
The compound (c) having two or more epoxy groups in the molecule is used for the purpose of imparting flexibility to the polyester resin (A) containing a bromine atom used in the present invention. Specific examples of such a compound include an epoxy compound having a polyalkylene oxide in a molecule such as polyethylene glycol diglycidyl ether and polypropylene glycol diglycidyl ether. )

(R ³ represents an alkylene group which may have a substituent having 12 to 30 carbon atoms or an alkenylene group which may have a substituent.)
The compound shown by is especially preferable.

Here, R ³ represents an alkylene group which may have a substituent or an alkenylene group which may have a substituent, but those having 12 to 30 carbon atoms are preferred from the viewpoint of flexibility. Specific examples of the alkylene group which may have a substituent include dodecylene group, tetradecylene group, hexadecylene group, octadecylene group, icosylene group, tetracosylene group, octacosylene group, 7-ethylhexadecylene group and the like. Specific examples of the alkenylene group which may have a substituent include a 7,11-octadecadienylene group and a 7,12-dimethyl-7,11-octadecadienylene group. In particular, from the viewpoint of imparting flexibility and easy availability of raw materials, a compound having a 7,11-octadecadienylene group or a 7,12-dimethyl-7,11-octadecadienylene group is preferably used. it can.

1-4. Method for Producing Polyester Resin Containing Bromine Atom in Molecule The production method for the polyester resin (A) having a bromine atom in the molecule used in the present invention is not particularly limited. For example, two or more in the molecule Of the compound (a) having a bromine atom and two or more hydroxyl groups and the acid anhydride group of the compound (b) having an acid anhydride group to react with an oligoester (A1 (Step 1), and then reacting the epoxy group of the compound (c) having two epoxy groups in the molecule (Step 2).

1-4-1. Process 1
The step of reacting the hydroxyl group of compound (a) with the acid anhydride group of compound (b) is carried out without a catalyst or, if necessary, using a catalyst.
As the catalyst, tertiary amines such as triethylamine, trioctylamine, benzyldimethylamine, and 2,4,6-tris (dimethylaminomethyl) phenol are preferably used. Although there is no restriction | limiting in particular in the reaction temperature of the addition reaction in the process 1, Generally it is 0-200 degreeC, Preferably it is 20-150 degreeC, More preferably, it is 50-120 degreeC. If it is 0 ° C. or lower, the reaction is very slow, and if it is 200 ° C. or higher, polymerization or decomposition is caused, which is not preferable.

  An organic solvent can be used for the addition reaction in Step 1. In particular, when a solid or high viscosity raw material is used, it is preferable to use an organic solvent because stirring becomes difficult. The organic solvent is not particularly limited as long as it does not inhibit the addition reaction. For example, benzene, toluene, xylene, tetrahydrofuran, dibutyl ether, diethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl Ether acetate, diethylene glycol ethyl ether acetate, methyl methoxypropionate, ethyl methoxypropionate, methyl ethoxypropionate, ethyl ethoxypropionate, ethyl acetate, isoamyl acetate, ethyl lactate, acetone, methyl ethyl ketone, cyclohexanone, N, N-dimethylformamide, N-methylpyrrolidone etc. can be mentioned. These solvents can be used alone or in combination of two or more.

  The molar ratio at the time of reaction of the compound (a) and the compound (b) in the step 1 is preferably (a) / (b) = 0.45 to 0.55, and more preferably 0.48 to 0.52. When the molar ratio is less than 0.45, the residual amount of the compound (b) increases, and the properties of the cured product are deteriorated. On the other hand, when it becomes larger than 0.55, the oligoester (A1) has a hydroxyl group at the molecular end, and it becomes difficult to react with the compound (c) in Step 2.

1-4-2. Process 2
In the reaction of the oligoester (A1) and the compound (c), it is preferable to use a catalyst for promoting the reaction. The catalyst is not particularly limited as long as it is generally used in the reaction between an epoxy group and a carboxyl group. Specific examples include metal halides such as aluminum chloride, tin chloride and zinc chloride, pyridine compounds such as pyridine, α-picoline, isoquinoline and quinoline, pyridinium salts such as N-methylpyridinium chloride and N-ethylpyridinium chloride, Quaternary ammonium salts such as benzyltrimethylammonium chloride, benzyltriethylammonium chloride, tetrabutylammonium bromide, phosphine compounds such as triphenylphosphine, ethyltriphenylphosphonium bromide, tetraphenylphosphonium bromide, benzyltriphenylphosphorus Phosphonium salts such as nium chloride, hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide, and carbonates such as potassium carbonate and calcium carbonate. Rukoto can.

  Among these, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, tetrabutylammonium bromide, ethyltriphenylphosphonium bromide, tetraphenyl are particularly useful because of their availability, speed of addition reaction, and the difficulty of side reactions. Phosphonium bromide and benzyltriphenylphosphonium chloride are preferred.

  In step 2, an organic solvent can be used. In particular, when a solid or high-viscosity raw material is used, it is preferable to use an organic solvent because stirring becomes difficult, and it is more preferable to carry out the reaction in an organic solvent that is inert (not reacting) with respect to the epoxy group. As such an organic solvent, the same solvent as in Step 1 is preferable.

  Although there is no restriction | limiting in particular in the reaction temperature of the addition reaction of the process 2, Generally it is 0-200 degreeC, Preferably it is 20-150 degreeC, More preferably, it is 50-120 degreeC. The reaction is very slow at 0 ° C. or lower, and decomposition is caused at 200 ° C. or higher, which is not preferable.

  In this step 2, the ratio (molar ratio) during the reaction of the oligoester (A1) and the compound (c) is preferably (A1) / (c) = 0.5 to 2, more preferably 1.1 to 2. If the ratio is less than 0.5, the oligoester (A1) is excessive, and if it is greater than 2, the compound (c) is excessive, both of which deteriorate the properties of the cured product.

  Moreover, the quantity of the catalyst used at these processes 1 and 2 is 0.01-10 mass% with respect to the sum total of the raw material in each process, Preferably it is 0.1-5 mass%. If the amount is less than 0.01% by mass, the reaction rate becomes slow, so that the heating time becomes long, making it difficult to produce at an economical cost, which is not preferable. On the other hand, if the amount is more than 10% by mass, coloring may be remarkable, which is not preferable.

2. Resin component other than polyester resin (A) having bromine atom in molecule As resin component other than polyester resin (A) having bromine atom in molecule used in the present invention, it can react with the polyester resin and is a solder resist. A thermosetting resin that can be used in the composition for use is preferable.

Examples of such thermosetting resins include epoxy resins, phenol resins, vinyl ester resins, polyester resins, urethane resins, silicone resins, acrylic resins, melamine derivatives (eg, hexamethoxymelamine, hexabutoxylated melamine, condensed hexamethoxymelamine). Etc.), urea compounds (for example, dimethylol urea), bisphenol compounds (for example, tetramethylol / bisphenol A), oxazoline compounds, and the like. These thermosetting resins can be used alone or in combination of two or more.
Among these, an epoxy resin is preferable from the viewpoints of long-term insulation characteristics, heat resistance, and processability.

2-1-1. Epoxy resin Epoxy resin is a compound containing two or more oxirane groups in one molecule. Specifically, bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol F Type epoxy resin, novolak type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, triphenylmethane type epoxy resin, N-glycidyl type epoxy resin, bisphenol A novolak type epoxy resin, rubber modified epoxy resin, dicyclo Examples thereof include an epoxy compound having two or more epoxy groups in one molecule such as a pentadiene phenolic epoxy resin, a silicone-modified epoxy resin, and an ε-caprolactone-modified epoxy resin. Furthermore, bisphenol S type epoxy resin, diglycidyl phthalate resin, heterocyclic epoxy resin, bixylenol type epoxy resin, biphenyl type epoxy resin and the like can be mentioned. In the present invention, these epoxy resins can be used alone or in combination of two or more.

2-1-2. Epoxy resin curing catalyst The epoxy resin can be cured in the presence of a curing catalyst. Examples of such curing catalysts include compounds having a catalytic action for promoting the polymerization of epoxy groups such as tertiary amines and imidazole compounds.
Specific examples of the tertiary amine compound include triethylamine, dimethylcyclohexylamine, N, N-dimethylpiperazine, benzyldimethylamine, 2- (N, N-dimethylaminomethyl) phenol, 2,4,6-tris (N , N-dimethylaminomethyl) phenol, 1,8-diazabiscyclo (5.4.0) undecene-1, and the like.

Specific examples of the imidazole compound include 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole. 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-methylimidazole trimellitate, 1-cyanoethyl-2-undecylimidazolium trimellitate, 2,4-diamino-6- [2′-methyl Imidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-undecylimidazolyl- (1 ′)]-ethyl-s-triazine, 2-methylimidazole isocyanuric acid addition , 2-phenylimidazole / isocyanuric acid adduct, 2 , 4-Diamino-6- [2′-methylimidazolyl- (1 ′)]-ethyl-s-triazine / isocyanuric acid adduct and the like.
More detailed specific examples of these tertiary amine compounds and imidazole compounds are described in "New Development of Epoxy Resin Curing Agent" (CMC Co., Ltd., 1994) pages 94-107.

2-1-3. Epoxy resin curing agent In addition to the curing catalyst, a compound having a functional group that reacts with an epoxy group (curing agent) can be used for curing the epoxy resin. Examples of the curing agent include a compound having a functional group to be added to an epoxy group, such as a primary or secondary amine compound, an acid anhydride compound, or a phenol compound.

  Specific examples of the primary or secondary amine compound include ethylenediamine, triethylenetetramine, polyoxypropylenediamine, isophoronediamine, bis (4-amino-3-methyldicyclohexyl) methane, bis (aminomethyl) cyclohexane, norbornenediamine. 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro (5.5) undecane, aliphatic amines such as m-xylylenediamine, m-phenylenediamine, diaminodiphenylmethane, Aromatic amines such as diaminodiphenyl sulfone and α, α′-bis (4-aminophenyl) -p-diisopropylbenzene are exemplified. Details are described in “New Development of Epoxy Resin Curing Agent” (CMC Co., Ltd., published in 1994), pages 41-93.

  Acid anhydride compounds include maleic anhydride, succinic anhydride, dodecenyl succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride , Endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, chlorendic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, ethylene glycol bis (anhydrotrimellilate), Examples thereof include glycerol tris (anhydro trimellitate), polyazeline acid anhydride, polydodecanedioic acid anhydride, 7,12-dimethyl-7,11-octadecadien-1,18-dicarboxylic acid partial anhydride, and the like. The details are described in “New Development of Epoxy Resin Curing Agent” (CMC Co., Ltd., published in 1994), pages 117-145.

Specific examples of phenolic compounds include bisphenol F, bisphenol A, bisphenol S, phenol novolak, o-cresol novolak, p-cresol novolak, t-butylphenol novolak, dicyclopentadiene cresol, poly-p-vinylphenol, bisphenol A. A type novolak is exemplified. Details are described in “New Development of Epoxy Resin Curing Agent” (CMC, 1994) pages 149-162.
In order to increase the reactivity of the acid anhydride compound and the phenol compound with the epoxy group, the above-described tertiary amine compound or imidazole compound may be added.

3. Other additives 3-1. Flame retardant imparting agent other than polyester resin (A) having bromine atom in molecule (B)
In the flame retardant composition for a solder resist of the present invention, a flame retardant imparting agent (B) other than the polyester resin (A) having a bromine atom in the molecule may be blended.
Examples of such a flame retardant imparting agent include bromine compounds (B1), hydrated metal compounds (B2), phosphorus compounds (B3), and antimony compounds (B4).

  The bromine compound (B1) is preferably a compound having a bromine content of 40% by mass or more, more preferably 45% by mass or more from the viewpoint of flame retardancy. Specific examples include brominated bisphenol A type epoxy resin, brominated cresol novolac type epoxy resin, tetrabromobisphenol A carbonate oligomer, tetrabromobisphenol A, tetrabromobisphenol A-bis (2,3-dibromopropyl ether), tetra Bromobisphenol A-bis (allyl ether), tetrabromobisphenol A-bis (bromoethyl ether), tetrabromobisphenol A-bis (ethoxylate), tetrabromobisphenol S, tetrabromobisphenol S-bis (2,3-dibromo Propyl ether), brominated phenylglycidyl ether, hexabromobenzene, pentabromotoluene, hexabromocyclododecane, decabromodiphenyl oxide, octabu Modiphenyl oxide, ethylenebis (pentabromophenyl), ethylenebis (tetrabromophthalimide), tetrabromophthalic anhydride, tribromophenol, tris (tribromophenoxy) triazine, polydibromophenylene oxide, bis (tribromophenoxyethane), Examples thereof include tribromoneopentyl glycol, dibromoneopentyl glycol, pentabromobenzyl acrylate, dibromostyrene, tribromostyrene, poly (pentabenzyl acrylate), brominated polystyrene and the like.

  The hydrated metal compound (B2) is a metal compound having water of crystallization, and examples thereof include, but are not limited to, those in which the amount of bound water per mole by thermal analysis is 12 to 60% (mass%). It is not a thing. From the viewpoint of flame retardancy and the like, preferably, a hydrated metal compound having an endothermic amount at the time of thermal decomposition of 400 J / g or more, preferably 600 to 2500 J / g is used. Specific examples of such hydrated metal compounds include aluminum hydroxide, magnesium hydroxide, calcium hydroxide, dosonite, calcium aluminate, dihydrate gypsum, zinc borate, barium metaborate, zinc hydroxystannate, kaolin. And vermiculite. Of these, aluminum hydroxide and magnesium hydroxide are particularly preferred.

  The particle size of the hydrated metal compound used in the present invention is not particularly limited, but the average particle size is preferably 40 μm or less, more preferably 2 μm or less. When the average particle diameter exceeds 40 μm, the transparency of the cured resist film is deteriorated and the light transmittance may be lowered, or the appearance and smoothness of the coating film surface may be impaired.

  As the hydrated metal compound (B2) used in the present invention, those subjected to surface treatment with a polar surface treatment agent are particularly preferable from the viewpoint of improving transparency. Examples of the surface treatment agent having such polarity include silane coupling agents and titanate coupling agents such as epoxy silane, amino silane, vinyl silane, and mercapto silane.

The phosphorus compound (B3) used in the present invention is preferably a compound having a chemical structure of “P—O—Y” (wherein Y is an organic group), and usually has a trivalent phosphorus atom. Or a pentavalent thing is used. Trivalent compounds include phosphite compounds, phosphonite compounds, and phosphinite compounds. On the other hand, those having a pentavalent phosphorus atom include phosphate compounds, phosphonate compounds, and phosphinate compounds. Among these, a phosphate ester compound having a pentavalent phosphorus atom is preferably used from the viewpoint of storage stability.
The organic group forming the ester of these phosphate ester compounds may be any of an aliphatic hydrocarbon group, an aromatic hydrocarbon group, an alicyclic hydrocarbon group, etc., among which flame retardancy and solder From the viewpoint of heat resistance, those having an aromatic hydrocarbon group are preferred.

  Examples of such phosphate ester compounds include triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, resorcinol bis (diphenol) phosphate, bisphenol A bis (diphenyl phosphate), 2-ethylhexyl diphenyl phosphate, 10- (2,5-dihydroxyphenyl) -10H-9-oxa-10-phosphaphenanthrene = 10-oxide and the like.

In addition to the above phosphorus compounds, phosphazene compounds having a structure of “—P (Y) ₂ ═N—” (where Y is an organic group), phosphorus-containing epoxy resins, and the like can be used without any problem. be able to.
Specific examples of the antimony compound (B4) used in the present invention include antimony trioxide, antimony tetraoxide, antimony pentoxide, and sodium antimonate.

3-2. Organic Solvent The flame retardant composition for a solder resist of the present invention may be used by adding an organic solvent as necessary for adjusting the viscosity. By adjusting the viscosity, it becomes easy to apply or print on an object by roller coating, spin coating, screen coating, curtain coating or the like.

  As organic solvents, isopropanol, 1-butanol, toluene, xylene, ethylbenzene, cyclohexane, isophorone, ethylene glycol monoacetate, diethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n -Butyl ether, propylene glycol monomethyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, diethylene glycol ethyl ether acetate, methyl methoxypropionate, ethyl methoxypropionate, methyl ethoxypropionate, ethyl ethoxypropionate, ethyl acetate, isoamyl acetate , Lactic acid Chill, acetone, methyl ethyl ketone, cyclohexanone, N, N- dimethylformamide, N- methylpyrrolidone and the like. You may use these individually or in combination of 2 or more types.

  The amount of the organic solvent used is preferably adjusted so that the flame retardant composition for the solder resist has a viscosity of 500 to 500,000 mPa · s (measured value at 25 ° C. using a B-type viscometer). A more preferable viscosity is 1,000 to 500,000 mPa · s. When the viscosity is in this range, it is suitable for application to an object and printing, and becomes easier to use. Moreover, the usage-amount of the organic solvent for setting it as such a viscosity is 1.5 mass times or less with respect to solid content other than an organic solvent. When the amount of the organic solvent used exceeds 1.5 mass times, the solid content becomes low. When printing this flame retardant composition for solder resist on a substrate or the like, a sufficient film thickness cannot be obtained by a single printing. , Many times of printing may be required.

3-3. Others A colorant may be further added to the flame retardant composition for a solder resist of the present invention to be used as an ink. Examples of the colorant include phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, crystal violet, titanium oxide, carbon black, naphthalene black and the like. When used as an ink, the viscosity is preferably 500 to 500,000 mP · s (measured value at 25 ° C. by a B-type viscometer).

  In order to adjust fluidity, a flow regulator can be further added to the flame retardant composition for solder resist of the present invention. For example, when the flame retardant composition for solder resist is applied to an object by roller coating, spin coating, screen coating, curtain coating, etc., the fluidity modifier appropriately controls the fluidity of the flame retardant composition for solder resist. Can be adjusted. Examples of the flow regulator include inorganic and organic fillers, waxes, surfactants and the like.

  Specific examples of the inorganic filler include talc, barium sulfate, barium titanate, silica, alumina, clay, magnesium carbonate, calcium carbonate, aluminum hydroxide, and a silicate compound. Specific examples of the organic filler include silicone resin, silicone rubber, and fluorine resin. Specific examples of the wax include polyamide wax and oxidized polyethylene wax. Specific examples of the surfactant include silicone oil, higher fatty acid ester, amide and the like. These fluidity modifiers can be used alone or in combination of two or more. Of these, the use of an inorganic filler is preferable because not only the fluidity of the flame retardant composition for solder resist but also the properties such as adhesion and hardness can be improved.

Moreover, additives, such as a thermal-polymerization inhibitor, a thickener, an antifoamer, a leveling agent, an adhesiveness imparting agent, can be added to the flame retardant composition for a solder resist of the present invention as necessary. Examples of the thermal polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, tert-butylcatechol, pyrogallol, phenothiazine and the like. Examples of the thickener include asbestos, olben, benton, montmorillonite and the like. An antifoaming agent is used in order to erase the foam which arises at the time of printing, coating, and hardening. Specific examples include acrylic and silicone surfactants. The leveling agent is used to lose unevenness on the surface of the film that occurs during printing and coating. Specific examples include acrylic and silicone surfactants. Examples of the adhesion imparting agent include imidazole, thiazole, triazole, and silane coupling agents.
In addition, an ultraviolet inhibitor, a plasticizer, and the like can be added for storage stability within a range that does not impair the gist of the present invention.

4). Method for Producing Flame Retardant Composition for Solder Resist The flame retardant composition for solder resist of the present invention can be produced by mixing each of the above components by a usual method. The mixing method is not particularly limited, and a part of the components may be mixed and then the remaining components may be mixed, or all the components may be mixed at once.
Specifically, after mixing each of the above-described components, it is produced using a known kneading method such as a kneader, three rolls, or a bead mill.

5). Cured product and use of flame retardant composition for solder resist The flame retardant composition for solder resist of the present invention can be obtained by applying a heat treatment on a substrate or the like and then heat-treating it as it is.
The flame retardant composition for a solder resist of the present invention maintains high flexibility despite having excellent flame retardancy, and unlike the case where other flame retardants are blended, thermosetting does not decrease, Furthermore, it is possible to form a cured film that satisfies performances such as heat resistance, electrical insulation, and adhesion to a wiring board. And since this cured film is particularly excellent in flame retardancy, flexibility, and electrical insulation, even when used on a thin wiring board such as an FPC board, curling does not occur, and electrical performance and handleability are also improved. An excellent insulating protective film having excellent flexibility can be formed. Moreover, the composition of this invention can be used conveniently also as an interlayer insulation resin layer of a multilayer printed wiring board.

  The insulating protective coating is formed by applying a flame retardant composition for solder resist to a thickness of 10 to 100 μm on a substrate on which a circuit is formed, and then heat-treating it in a temperature range of 100 to 200 ° C. for 10 to 60 minutes to cure. Can be formed.

  The flame retardant composition for a solder resist of the present invention can be used for various applications, in particular, flame retardancy, thermosetting, adhesion to a substrate, insulation, heat resistance, warp deformation, flexibility, etc. It is suitable for use as an insulating protective film for printed wiring boards that require these characteristics and as an interlayer insulating resin layer for multilayer printed wiring boards.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

<Synthesis of polyester resin (A) containing bromine atom in molecule>
Synthesis example 1:
PHT-4 diol (trade name: 3,4,5,6-tetrabromophthalic acid mixed ester of propylene glycol and diethylene glycol, hydroxyl group equivalent 279, manufactured by Great Lakes Chemical Corporation) 200 g, succinic anhydride (acid anhydride group equivalent 100) , Tokyo Chemical Co., Ltd.) 71.9 g and diethylene glycol ethyl ether acetate (Tokyo Kasei Co., Ltd.) 125.2 g are charged into a 500 ml four-necked separable flask, and a thermometer, a stirrer, a nitrogen inlet tube, and a condenser are provided. And then reacted at 120 ° C. for 5 hours in a nitrogen stream. After confirming that the absorption derived from the carbonyl group of the acid anhydride group disappeared with an infrared spectrophotometer (FT / IR8000 manufactured by JASCO Corporation, hereinafter referred to as “FT-IR”), the mixture was allowed to cool to room temperature. . Furthermore, IPU-22G (trade name 8,13-dimethyl-8,12-eicosadienedioic acid = bis (2,3-epoxypropyl), epoxy equivalent 279, manufactured by Okamura Oil Co., Ltd.) 100.6 g, tetrabutylammonium After adding 3.48 g of bromide, the reaction was carried out at 110 ° C. After 10 hours of reaction, it was confirmed that the acid value was almost constant, and then allowed to cool. The obtained resin had a solid content concentration of 75% by mass, a solid content acid value of 60 mgKOH / g, a bromine content of 27.1% by mass, and a weight average molecular weight in terms of polystyrene by GPC (gel permeation chromatography) of 3000. there were.

Synthesis example 2:
PHT-4diol 160g, succinic anhydride 57.5g, diethylene glycol ethyl ether acetate 113.5g were charged into a 500ml four-necked separable flask, and a thermometer, a stirrer, a nitrogen inlet tube and a condenser were added, and then in a nitrogen stream 120 The reaction was carried out for 6 hours at ° C. After confirming that the absorption derived from the carbonyl group of the acid anhydride group disappeared by FT-IR, the mixture was allowed to cool to room temperature. Further, 120.2 g of IPU-22G and 2.78 g of tetrabutylammonium bromide were added, and the reaction was performed at 110 ° C. After 10 hours of reaction, it was confirmed that the acid value was almost constant, and then allowed to cool. The obtained resin had a solid content concentration of 75% by mass, a solid content acid value of 30 mgKOH / g, a bromine content of 26.8% by mass, and a weight average molecular weight in terms of polystyrene by GPC of 6000.

Synthesis Example 3:
500 ml 4-neck separable of dibromoneopentyl glycol (hydroxyl equivalent 131, produced by Bromchem Far East Co., Ltd.) 118.9 g, succinic anhydride 90.9 g, diethylene glycol ethyl ether acetate (produced by Tokyo Chemical Industry Co., Ltd.) 108.7 g The flask was charged, a thermometer, a stirrer, a nitrogen introduction tube and a condenser were added, and then reacted at 120 ° C. for 6 hours in a nitrogen stream. After confirming that the absorption derived from the carbonyl group of the acid anhydride group disappeared by FT-IR, the mixture was allowed to cool to room temperature. Furthermore, SB-20G (trade name 8,12-eicosadiene diacid = bis (2,3-epoxypropyl), epoxy equivalent 249, manufactured by Okamura Oil Co., Ltd.) 113.0 g, tetrabutylammonium bromide 3.24 g were added. Thereafter, the reaction was carried out at 110 ° C. After 10 hours of reaction, it was confirmed that the acid value was almost constant, and then allowed to cool. The obtained resin had a solid content concentration of 75% by mass, a solid content acid value of 79 mgKOH / g, a bromine content of 22.2% by mass, and a weight average molecular weight in terms of polystyrene by GPC of 3000.

Examples 1-8 and Comparative Examples 1-2:
A flame retardant composition was prepared by mixing three times through a three roll mill (Model RIII-1RM-2, manufactured by Kodaira Seisakusho Co., Ltd.) three times with the mixing ratio shown in Table 1 separately.

The following evaluation was implemented about each obtained flame-retardant composition.
-Thermosetting 25 pm thick polyimide film [Kapton (registered trademark) 100H, manufactured by Toray DuPont Co., Ltd.] coated with a flame retardant composition for each solder resist by screen printing with a 150 mesh polyester plate, circulating hot air at 150 ° C It put into the type | formula dryer, and thermosetting was performed for 20 minutes, 40 minutes, and 60 minutes, respectively. Furthermore, several drops of ethyl acetate were added to the heat-cured coating film, and the state of the coating film after rubbing with Kimwipe was visually observed. If cured, no change is seen in the coating. The evaluation criteria for thermosetting are shown below.
○: No change is seen in the coating film,
Δ: Whitening of the coating film
X: The coating film is dissolved.

-Flexibility The flame retardant composition for each solder resist was applied to a substrate by screen printing with a 150 mesh polyester plate, and was thermally cured at 150 ° C for the time determined as ◯ in the thermosetting evaluation. As the substrate, the above-mentioned 25 μm thick polyimide film was used. The obtained polyimide film was bent 180 ° outward so that the cured film was whitened by visual observation. Judgment criteria are shown below.
○: No whitening of the cured film,
X: The cured film is whitened or cracked.

Solder heat resistance According to the test method of JIS · C-6481, each flame resist composition for solder resist was applied to a substrate with a 150 mesh polyester plate by screen printing, and judged as ○ in the above thermosetting evaluation at 150 ° C. For a set time. The substrate is a printed board made of copper foil (thickness 35 μm), single area polyimide film (thickness 50 μm) [Iupicel (registered trademark) N, manufactured by Ube Industries, Ltd.] washed with 1% sulfuric acid aqueous solution, washed with water, and air What was dried in a stream was used.
The obtained substrate was floated in a solder bath at 260 ° C. for 5 seconds as one cycle, and the cured film was visually observed for each cycle, and it was confirmed that there was no change and no change was observed. The maximum number of cycles when repeated.

・ Flammability A flammability test piece was prepared by the following method. A flame retardant composition layer for a solder resist having a thickness of 20 μm was provided on both sides of a polyimide film having a thickness of 25 μm and a thickness of 200 mm × 50 mm (manufactured by Toray DuPont Co., Ltd., Kapton 100H).
As for the combustion characteristics, flame retardancy was evaluated by a method based on a flame retardant test standard 94UL-VTM test for polymer materials of Underwriters Laboratories Inc. (abbreviated as UL) in the United States.
“VTM” and “NOT” in Table 2 are based on the following criteria.

VTM-0: All the following requirements are satisfied.
(1) All specimens do not burn in flames for more than 10 seconds after stopping each flame contact.
(2) Each set of 5 test pieces is subjected to flame contact 10 times in total, and the total flame burning time does not exceed 50 seconds.
(3) Flame or red heat combustion does not reach the 125 mm mark.
(4) Absorbent cotton does not ignite due to flammable drops.
(5) After the second flame contact is stopped, the sum of the flame and red heat combustion of each sample does not exceed 30 seconds.
(6) If only one of the five test pieces in the set is not suitable for the requirement, or if the total flame time is in the range of 51 to 55 seconds, then another five test pieces are tested. All satisfy (1) to (5).

VTM-1: All the following requirements are satisfied.
(1) All specimens do not burn in flames for more than 30 seconds after each flame contact is stopped.
(2) A total of 10 flames are contacted to each group of five test pieces, and the total flame burning time does not exceed 250 seconds.
(3) Flame or red heat combustion does not reach the 125 mm mark.
(4) Absorbent cotton does not ignite due to flammable drops.
(5) After stopping the second flame contact, the sum of the flaming and red hot combustion of each sample does not exceed 60 seconds.
(6) When only one set of five test pieces is not suitable for the requirement, or when the total flame time is in the range of 251 seconds to 255 seconds, another five test pieces are tested. All satisfy (1) to (5).

VTM-2: All of the following requirements are satisfied.
(1) All specimens do not burn in flames for more than 30 seconds after each flame contact is stopped.
(2) A total of 10 flames should be applied to each group of 5 test pieces, and the total flammable combustion time shall not exceed 250 seconds.
(3) The flame or red heat combustion must not reach the 125 mm mark.
(4) Absorbent cotton may be ignited by the flamed drop.
(5) After the second flame contact is stopped, the total flame and red heat combustion of each sample does not exceed 60 seconds.
(6) When only one set of five test pieces is not suitable for the requirement, or when the total flame time is in the range of 251 seconds to 255 seconds, another five test pieces are tested. All satisfy (1) to (5).

NOT: Does not pass any of the above classes.

・ Electrical insulation (insulation resistance)
In the evaluation of the thermosetting property at 150 ° C., the flame retardant composition for each solder resist was applied by screen printing with a 150 mesh polyester plate on IPC-C (comb pattern) of a commercially available substrate (IPC standard). It was thermoset at the time judged as ○. The substrate was left for 192 hours in an atmosphere of 85 ° C. and relative humidity of 85%, and the insulation resistance value was measured before and after this treatment to evaluate the electrical insulation. The insulation resistance value was measured by applying an electric insulation meter to the substrate before and after the treatment in accordance with JIS C5012 after applying a 100 V DC voltage for 1 minute and applying the voltage.
The obtained evaluation results are shown in Table 2.

Claims (14)

  A flame retardant composition for a solder resist, comprising a polyester resin (A) containing a bromine atom in the molecule.   The flame retardant composition for a solder resist according to claim 1, wherein the content of the polyester resin (A) containing a bromine atom in the molecule in the resin component is 10 to 70% by mass.   The polyester resin (A) containing a bromine atom in the molecule contains a compound (a) having two or more bromine atoms and two or more hydroxyl groups in the molecule, a compound (b) having an acid anhydride group, and a molecule The flame retardant composition for a solder resist according to claim 1 or 2, which is a resin obtained by reacting a compound (c) having two epoxy groups with the resin. The compound (a) having two or more bromine atoms and two or more hydroxyl groups in the molecule is represented by the following formula (1):

(In the formula, at least two of X ¹ , X ² , X ³ and X ⁴ represent bromine atoms, the rest represent hydrogen atoms, and R ¹ and R ² each represent a divalent organic group.) The flame retardant composition for a solder resist according to claim 3, which is a compound represented by the formula: and / or dibromoneopentyl glycol. The compound (a) represented by the formula (1) is represented by the following formula (2)

The flame retardant composition for a solder resist according to claim 4, which is a compound represented by the formula: The compound (c) having two epoxy groups in the molecule is represented by the formula (3)

(In the formula, R ³ represents an alkylene group having 12 to 30 carbon atoms which may have a substituent or an alkenylene group which may have a substituent.)
The flame-retardant composition for solder resists of Claim 3 shown by these. The flame retardant composition for a solder resist according to claim 6, wherein R ³ is a 7,11-octadecadienylene group or a 7,12-dimethyl-7,11-octadecadienylene group.   Hardened | cured material of the flame retardant composition for soldering resists of any one of Claims 1 thru | or 7.   An ink comprising the flame retardant composition for a solder resist according to any one of claims 1 to 7 and a colorant.   The resist curable flame retardant composition according to any one of claims 1 to 7 is applied to a substrate with a thickness of 10 to 100 µm, and then cured by heat treatment at a temperature range of 100 to 200 ° C for 10 to 60 minutes. A method for curing a flame retardant composition for a solder resist, characterized by comprising:   An insulating protective film comprising the flame retardant composition for a solder resist according to any one of claims 1 to 7.   An interlayer insulating film comprising the flame retardant composition for a solder resist according to any one of claims 1 to 7.   A printed wiring board comprising the insulating protective film according to claim 11. A printed wiring board comprising the interlayer insulating film according to claim 12.