JP5048364B2 - Flame retardant adhesive resin composition and coverlay film using the same - Google Patents

Description

  The present invention relates to a heat-resistant adhesive resin composition and a cover lay film, and more particularly to a high heat-resistant and flame-retardant adhesive resin composition and a cover lay film substantially free of halogen elements.

As a printed wiring board, conventionally, a base material made of paper-phenolic resin, glass fiber-epoxy resin, or a base material such as a polyimide film or a polyethylene terephthalate film and a metal foil are used.
In the present specification, a printed wiring board refers to a laminate before circuit processing, a circuit processed from this metal foil is referred to as a printed wiring board, and both are referred to as printed boards.

  Further, in recent years, printed wiring boards used in the fields of electrical / electronic equipment and precision equipment have a reduced wiring occupation area, and thus the demand for multilayer printed circuit boards has been increasing. Various adhesives or adhesive films are used in the process of producing a multilayer printed wiring board by laminating printed wiring boards or compounding different kinds of circuit materials.

  As such an adhesive, a prepreg adhesive in which a woven fabric such as glass fiber is impregnated with an epoxy or bismaleimide resin is known. However, these have problems such as insufficient flexibility and poor dimensional stability. Conventionally, adhesives such as acrylonitrile butadiene rubber / phenol resin, phenol resin / butyral resin, acrylonitrile butadiene rubber / epoxy resin have been proposed (for example, JP-A-4-29393 and JP-A-4-36366). JP-A-4-41581). However, these adhesives do not have sufficient chemical resistance and heat resistance, have large thermal degradation, have insufficient heat resistance to moisture-absorbing solder, and workability such as the occurrence of smear during drilling to form through holes. The point was not enough.

  In addition, a polyimide adhesive having excellent heat resistance has also been proposed (see, for example, US Pat. No. 4,543,295). However, such a polyimide has difficulties in practical use because it requires a thermocompression bonding temperature of 250 ° C. or higher in order to bond substrates such as copper or polyimide film and obtain satisfactory adhesive strength. It was.

  Patent Document 1 discloses an adhesive using polyimide made of diaminopolysiloxane and aromatic tetracarboxylic acid as raw materials for thermocompression bonding at a low temperature. However, such a polyimide alone has a drawback in that the adhesive strength is not sufficient and the reliability is poor.

  As a polyimide adhesive having excellent adhesive strength, for example, Patent Document 2 discloses a film adhesive made of polyamideimide and an epoxy resin as an adhesive for manufacturing a flexible printed wiring board. However, when such a film is used for bonding uneven surfaces on which circuits are formed, such as the production of multilayer printed wiring boards, the filling of the circuit surfaces is not sufficient, and sufficient heat resistance to the solder bath is obtained. I can't.

  For this reason, adhesives for multilayer printed circuit boards and adhesives for coverlay films can be pressed at a low temperature of 250 ° C or lower, and adhesive strength, chemical resistance, heat resistance, hygroscopic solder heat resistance, and dimensional stability during wiring processing Materials with excellent properties and the like have been demanded. Moreover, the material excellent in the flame retardance from the point of ensuring fire safety has been calculated | required.

  In the conventional adhesive film, a resin or additive containing a halogen such as bromine has been used to impart flame retardancy. Halogen has been widely used for the purpose of imparting flame retardancy, cost performance, and resistance to plastic deterioration. However, there is a concern that the halogen contained therein may cause harmful substances such as dioxin during combustion, and it is strongly desired to eliminate the halogen from the material.

  Various non-halogen materials have been developed as flame retardant materials that replace halogen. An example of such an adhesive film is Patent Document 3. However, such an adhesive film has a problem that the migration resistance is lowered by the inclusion of a metal hydroxide or the like.

  By the way, Patent Document 4 discloses a heat-resistant adhesive film for printed circuit boards made of a polyimide having a silicon unit and an epoxy resin. However, the epoxy resin used here is a general epoxy resin derived from bisphenol A or a phenol resin, and the type of polyimide and the combination with the epoxy resin are also general and are resistant to flame retardancy. Consideration was not enough. Patent Document 5 discloses an acenaphthylene-modified phenolic resin and an epoxy resin obtained by epoxidizing it. However, there is no disclosure about combining such acenaphthylene-modified phenolic resin or epoxy resin with polyimide to form an adhesive resin composition.

JP-A-4-23879 JP-A-52-91082 JP 2004-146286 A JP 2001-203467 A WO2003 / 104295

  An object of the present invention is to provide a non-halogen flame-retardant adhesive resin composition and a cover lay film that can be pressed at a low temperature of 250 ° C. or lower and that is excellent in heat resistance, hygroscopic solder heat resistance, workability, and the like. There is to do.

  As a result of intensive studies to achieve the above object, the present inventors have completed the present invention by using a specific plasticizer in a combination of a specific polyimide resin and an epoxy resin.

That is, this invention has the repeating unit represented by the following general formula (1) and the following general formula (2), and the composition ratio of the repeating unit represented by the general formulas (1) and (2) is ( 1) / (2) = Silicon unit-containing polyimide resin in a range of 50/50 to 10/90 (molar ratio) 65 to 98% by weight, and naphthol resin having a structure in which an acenaphthenyl group is substituted with a naphthalene ring is epoxidized 1 to 45 parts by weight of a phosphoric ester plasticizer having a molecular weight of 1000 or less is blended with 100 parts by weight of a mixed resin composed of 2 to 35% by weight of an acenaphthylene-modified epoxy resin having a structure obtained in the above manner. The flame retardant adhesive resin composition is substantially free of halogen elements. Here, the acenaphthylene-modified epoxy resin has a structure represented by the following general formula (4).

一般式（１）において、Ar₁は４価の芳香族基を示し、R₁及びR₂は２価の炭化水素基を示し、R₃及びR₄は炭素数１〜６の１価の炭化水素基を示し、mは１〜２０の数を示す。一般式（２）において、Ar₁は４価の芳香族基を示し、Ar₂は２価の芳香族基を示す。

In the general formula (1), Ar ₁ represents a tetravalent aromatic group, R ₁ and R ₂ represent a divalent hydrocarbon group, and R ₃ and R ₄ represent a monovalent carbon having 1 to 6 carbon atoms. A hydrogen group is shown, m shows the number of 1-20. In the general formula (2), Ar ₁ represents a tetravalent aromatic group, and Ar ₂ represents a divalent aromatic group.

（但し、Ar₃は３価又は４価の芳香族基を示し、Xは水酸基、アミノ基、カルボキシル基又はメルカプト基を示し、kは１又は２を示す） The flame retardant adhesive resin composition is excellent in a resin composition by containing 1 to 15 parts by weight of an epoxy resin curing agent with respect to 100 parts by weight of the total of the silicon unit-containing polyimide resin and the acenaphthylene-modified epoxy resin. Curability can be imparted and the physical properties of the cured resin can be improved. Moreover, 1-20 mol% of Ar < ₂ > in General formula (2) which is a repeating unit of the said silicon unit containing polyimide resin with the epoxy resin hardening | curing agent or instead of an epoxy resin hardening | curing agent is following General formula (3). By using a divalent aromatic group having a functional group reactive with the epoxy group represented, excellent curability can be given to the resin composition, and the physical properties of the cured resin can be improved.

(However, Ar ₃ represents a trivalent or tetravalent aromatic group, X represents a hydroxyl group, an amino group, a carboxyl group, or a mercapto group, and k represents 1 or 2)

（但し、Aはナフタレン核を示し、Gはグリシジル基を示し、Rはアセナフテニル基又は水素を示し、Xはアルキレン基又は-Y-Ar-Y-で表されるアラルキレン基を示し、pは０〜１５の数を示し、qは１又は２を示し、そしてR中にアセナフテニル基が占める割合は10モル％以上である。また、Yはアルキレン基を示し、Arは2価の芳香族基を示す。） The acenaphthylene-modified epoxy resin is preferably an epoxy resin having a structure represented by the following general formula (4) or (5).

(However, A represents a naphthalene nucleus, G represents a glycidyl group, R represents an acenaphthenyl group or hydrogen, X represents an alkylene group or an aralkylene group represented by -Y-Ar-Y-, and p represents 0. Represents a number of ˜15, q represents 1 or 2, and the proportion of acenaphthenyl group in R is 10 mol% or more, Y represents an alkylene group, and Ar represents a divalent aromatic group. Show.)

（但し、Aはナフタレン核を示し、Gはグリシジル基を示し、R₅、R₆及びR₈は水素原子又は炭素数１〜６のアルキル基を示し、R₇は下記式（a）で示されるアセナフテニル基又は水素を示すが10モル％以上はアセナフテニル基である。pは０〜１５の数であり、qは１又は２である。

(However, A represents a naphthalene nucleus, G represents a glycidyl group, R ₅ , R ₆ and R ₈ represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ₇ is represented by the following formula (a). 10 mol% or more is an acenaphthenyl group, p is a number from 0 to 15, and q is 1 or 2.

  Moreover, this invention is a flame-retardant adhesive film characterized by forming said flame-retardant adhesive resin composition into a film form.

Furthermore, the present invention is characterized in that the flame retardant adhesive film described above is inserted between objects to be bonded, and is used by thermocompression bonding under conditions of a pressure of 1 to 100 kg / cm ² and a temperature of 20 to 250 ° C. It is the usage method of a flame-retardant adhesive film.

Furthermore, the present invention provides a cover lay film formed from a base film and an adhesive resin composition, wherein the adhesive resin composition is the flame retardant adhesive resin composition described above. It is a film. Further, in the present invention, after covering the above-mentioned coverlay film so that a desired portion of the conductor circuit is coated on the circuit board on which the conductor circuit is formed, the pressure is 1 to 100 kg / cm ² , the temperature is 20 to An insulating coating is formed by thermocompression bonding under a condition of 250 ° C.

  Hereinafter, the present invention related to the flame-retardant adhesive resin composition will be described, and then the present invention related to the coverlay film will be described, but the common parts will be described simultaneously. First, each component of the flame retardant adhesive resin composition of the present invention will be described.

  The flame retardant adhesive resin composition of the present invention (hereinafter also referred to as a resin composition) has repeating units represented by the above general formula (1) and general formula (2), and includes the general formula (1) and (1) / (2) = 50/50 to 10/90 (molar ratio) -containing silicon unit-containing polyimide resin (hereinafter referred to as silicon unit-containing polyimide resin) Acenaphthylene-modified epoxy resin having a structure obtained by epoxidizing a naphthol resin having a structure in which an acenaphthenyl group is substituted with a naphthalene ring (hereinafter also referred to as acenaphthylene-modified epoxy resin), 2 to 35% by weight A resin composition containing 1 to 45 parts by weight of a phosphoric ester plasticizer to 100 parts by weight of a mixed resin comprising substantially no halogen element. That.

As the silicon unit-containing polyimide resin, it is desirable to use a solvent-soluble polyimide resin having good film moldability. Furthermore, if a functional group capable of reacting with an epoxy group is contained in the polyimide resin, the epoxy resin curing agent can be dispensed with or in a small amount. In order to have a functional group capable of reacting with an epoxy group in the polyimide resin, 1 to 20 mol%, preferably 2 to 10 mol%, of Ar ₂ in the general formula (2) is the general formula (3). There is a method of using a raw material aromatic diamine so that a polyimide resin having an aromatic group represented by

The silicon unit-containing polyimide resin is usually obtained by reacting diaminosiloxane and aromatic diamine with tetracarboxylic dianhydride. Since Ar ₁ in the above general formulas (1) and (2) can be said to be a residue of tetracarboxylic dianhydride, Ar ₁ is understood from the description of tetracarboxylic dianhydride. Moreover, since the silicon unit in General formula (1) can be said to be a residue of diaminosiloxane, a silicon unit is understood from diaminosiloxane description. Furthermore, since Ar ₂ in the general formula (2) can be said to be a residue of an aromatic diamine, Ar ₂ is understood from the explanation of the aromatic diamine.

  As specific examples of tetracarboxylic dianhydride, preferably 3,3 ′, 4,4′-diphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride, And one or more tetracarboxylic dianhydrides selected from 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride and 2,2 ′, 2,3′-benzophenone tetracarboxylic dianhydride. It is done. Also, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, 1,4,5 , 8-Naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 3,3,6,7 Other tetracarboxylic acids such as anthracene tetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, 4,4 ′-(hexafluoroisopyridene) phthalic dianhydride Although an anhydride is also mentioned, when using these other tetracarboxylic dianhydrides, it is good to use together with 1 or more types of the tetracarboxylic dianhydride mentioned as said preferable. When other tetracarboxylic dianhydrides are used in combination, the range of 5 to 50 mol% is preferable.

で表されるジアミノシロキサンが用いられる。一般式（５）において、R₁〜R₄は一般式（１）のそれらと同じ意味を有する。 As diaminosiloxane, the following general formula (5)

The diaminosiloxane represented by these is used. In the general formula (5), R _{1 to} R ₄ have the same meaning as those in the general formula (1).

R ₁ and R _{2 each} represent a divalent hydrocarbon group, preferably an alkylene group having 1 to 6 carbon atoms or a phenylene group. R ₃ and R ₄ each represent a hydrocarbon group having 1 to 6 carbon atoms, preferably an alkyl group having 1 to 6 carbon atoms or a phenyl group. These may be the same or different.

  m is in the range of 1-20, but is preferably in the range of 2-14 as a number average. When the amount is less than this range, when the flame retardant adhesive resin composition is formed into a film and used as a flame retardant adhesive film, the film filling property is lowered. The same applies to the silicon unit of the general formula (1).

  By using diaminosiloxane as a silicon unit-containing polyimide resin, the flame-retardant adhesive film of the present invention can be given fluidity during thermocompression bonding, and the filling property on the printed circuit board surface can be improved.

  Preferable specific examples of diaminosiloxane include diaminosiloxanes represented by the following formula.

  More preferable specific examples of the diaminosiloxane include phenyl group-substituted diaminosiloxanes represented by the following formula. Here, j and n in the following formula have a total number of j and n in the range of 1 to 20, but preferably in the range of 2 to 14.

In the general formula (2), specific examples of the aromatic diamine that gives Ar ₂ include m-phenylenediamine, p-phenylenediamine, 4,4′-diaminodiphenylpropane, 4,4′-diaminodiphenylmethane, and benzidine. 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diamino -P-terphenyl and the like are mentioned, but 2,2-bis (3-aminophenoxyphenyl) propane, 2,2-bis (4-aminophenoxyphenyl) propane, 3 for the purpose of improving the solubility in organic solvents. , 3-bis (3-aminophenoxyphenyl) sulfone, 4,4-bis (3-amino Phenoxyphenyl) sulfone, 3,3-bis (4-aminophenoxyphenyl) sulfone, 4,4-bis (4-aminophenoxyphenyl) sulfone, 2,2-bis (3-aminophenoxyphenyl) hexafluoropropane, 2, , 2-bis (4-aminophenoxyphenyl) hexafluoropropane, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 4,4- (p-phenylenediene) It is preferable to use one or more diamines having three or more aromatic rings such as isopropylidene) bisaniline and 4,4- (m-phenylenediisopropylidene) bisaniline. Aromatic diamines that give Ar ₂ do not have silicon units or siloxane units.

It is also advantageous to use a reactive aromatic diamine represented by the following general formula (7) having a functional group reactive with an epoxy resin as a part of the aromatic diamine.

In the general formula (7), Ar ₃ , X and k have the same meanings as those in the general formula (3). Such reactive aromatic diamines include 2,5-diaminophenol, 3,5-diaminophenol, 4,4 ′-(3,3′-dihydroxy) diaminobiphenyl, 4,4 ′-(2,2 '-Dihydroxy) diaminobiphenyl, 2,2'-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 3,3', 4,4'-biphenyltetraamine, 3,3 ', 4,4' -Tetraaminodiphenyl ether, 4,4 '-(3,3'-dicarboxy) diphenylamine, 3,3'-dicarboxy-4,4'-diaminodiphenyl ether, and the like are particularly preferable. At least one of (3,3′-dihydroxy) diphenylamine and 4,4 ′-(2,2′-dihydroxy) diphenylamine. By using the reactive aromatic diamine, it reacts with the epoxy resin at the time of thermocompression bonding to form a crosslinked structure, so that the adhesive strength and chemical resistance of the adhesive film of the present invention can be further improved. The reactive aromatic diamine is preferably used in the range of 1 to 20 mol%, more preferably in the range of 2 to 10 mol% of the total aromatic diamine.

  The silicon unit-containing polyimide resin is obtained by reacting the above diaminosiloxane and aromatic diamine with tetracarboxylic dianhydride in a solvent to form a precursor resin, and then heating and ring-closing the resin in the general formulas (1) and (2). A polyimide resin having a repeating unit represented can be produced. At this time, the constitutional ratio (molar ratio) of the repeating units represented by the general formulas (1) and (2) is (1) / (2) = 50/50 to 10/90, preferably 50/50 to 20 /. A range of 80. Outside this range, the effect of the present invention cannot be obtained.

  As the epoxy resin, an acenaphthylene-modified epoxy resin is used. The flame retardancy of the adhesive resin composition of the present invention can be improved by the contribution of the acenaphthenyl group-substituted naphthalene skeleton generated by the reaction of acenaphthylene with the naphthalene ring.

  The acenaphthylene-modified epoxy resin is obtained by reacting a naphthol resin, preferably a naphthol novolak resin with acenaphthylene, to obtain an acenaphthylene-modified naphthol resin having a structure in which an acenaphthenyl group is substituted on a naphthalene ring (naphthol ring), and then OH of the naphthol resin It has a structure obtained by epoxidizing a group with epichlorohydrin to form an OG group (glycidyl ether group). However, the method for producing the acenaphthylene-modified epoxy resin is not limited to the above method.

As an acenaphthylene modified epoxy resin, the epoxy resin represented by the said General formula (4) is illustrated preferably. In the general formula (4), A represents a naphthalene nucleus, G represents a glycidyl group, R represents an acenaphthenyl group or hydrogen, X represents an alkylene group or an aralkylene group represented by —Y—Ar—Y—. , P represents a number from 0 to 15, q represents 1 or 2, and the proportion of acenaphthenyl group in R is 10 mol% or more. Y represents an alkylene group, and Ar represents a divalent aromatic group. X and Y are alkylene groups, preferably an alkylene group having 1 to 3 carbon atoms, and more preferably a methylene group. X is derived from a cross-linking agent that reacts with naphthol when producing naphthol resin. When the cross-linking agent is formalin, a methylene group is provided, and when it is RO-H ₂ C-Ph-CH ₂ -OR (R is H or alkyl, Ph is phenylene), -H ₂ C-Ph-CH ₂ The aralkyl group represented by-is given. Ar represents a divalent aromatic group, and is preferably a phenylene group or a biphenylene group. A is a naphthalene nucleus, but at least 10 mol%, preferably 30 mol% or more, more preferably 40 mol% or more of all naphthalene nuclei are substituted with an acenaphthenyl group. If this substitution rate is low, sufficient flame retardancy cannot be obtained. Since the epoxy resin is a mixture, it is sufficient that the epoxy resin as a whole has 10 moles or more of acenaphthenyl groups per 100 moles of all naphthalene nuclei. However, although 80 mol% or more may be substituted with an acenaphthenyl group, the effect is saturated, so 20-80 mol%, preferably 30-70 mol% is preferable. Moreover, although p shows the number of 0-15, Preferably it is 0-5 as an average value, More preferably, it is the range of 0.1-3. q represents 1 or 2, but is preferably 1.

Moreover, as an acenaphthylene modified epoxy resin, the epoxy resin represented by the said General formula (5) is illustrated preferably. Here, A represents a naphthalene nucleus, G represents a glycidyl group, R ₅ , R ₆ and R ₈ represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and R ₇ is represented by the formula (a). An acenaphthenyl group or hydrogen, p is a number from 0 to 15 and q is 1 or 2; In addition, it can be understood that the symbol corresponding to the general formula (4) has a similar meaning. The substitution rate of the acenaphthenyl group is 10 mol% or more, preferably 30 mol% or more.

  A method for producing acenaphthylene-modified naphtholic epoxy resin will be described. Although not particularly limited, acenaphthylene, which is one of aromatic olefins, can be added to the naphthalene ring of the naphthol resin because the Friedel-Crafts reaction can be used. An epoxy resin can be obtained by reacting the naphthol resin having an acenaphthenyl group-substituted naphthalene skeleton thus obtained with epichlorohydrin using a known method. The naphthol resin used here may be a naphthol novolak resin or a naphthol aralkyl resin, but a naphthol aralkyl resin is preferred from the viewpoint of moisture resistance and impact resistance.

  The acenaphthylene-modified epoxy resin has an average of 0.1 or more, preferably 0.3 or more, more preferably 0.4 or more acenaphthylene added to one naphthalene nucleus having a naphthol structure. In addition, an acenaphthenyl group-unsubstituted naphthalene nucleus may be contained. When the naphthol resin is a naphthol aralkyl resin, when it reacts with acenaphthylene, acenaphthylene not only reacts with the naphthalene nucleus, but part of it may be substituted with a benzene ring that constitutes aralkyl. There is no problem.

  The acenaphthylene-modified epoxy resin is preferably an epoxy resin represented by the above formula (4) or (5).

Specifically, a naphthalene skeleton-containing epoxy resin represented by the following formula can be given.

More specifically, a naphthalene skeleton-containing epoxy resin represented by the following formula can be given.

  The blending ratio of the silicon unit-containing polyimide resin and the acenaphthylene-modified epoxy resin is 65 to 98% by weight of polyimide resin, 2 to 35% by weight of epoxy resin, preferably 70 to 90% by weight of polyimide resin, and 10 to 30% by weight of epoxy resin. It is a range. By mix | blending in this range, heat resistance and adhesiveness can further be improved, without reducing the original characteristic of a polyimide resin.

  The resin composition of the present invention comprises 1 to 45 parts by weight of a phosphate ester plasticizer in 100 parts by weight of a mixed resin of the polyimide resin containing the siloxane unit and the acenaphthylene-modified epoxy resin. Such a plasticizer is not particularly limited as long as it can be mixed with the polyimide resin, and further improves the low-temperature pressure-bonding property, filling property and flame retardancy without deteriorating the original properties of the polyimide resin. Can do. When the blending amount of the plasticizer is less than 1 part by weight, the effect of improving the low-temperature press bonding property and the circuit filling property is small, and when it exceeds 45 parts by weight, the adhesiveness, heat resistance and flame retardancy are lowered.

  The preferred molecular weight of the phosphoric ester plasticizer is 1000 or less. If the molecular weight exceeds this, the adhesive strength and heat resistance will decrease.

  Specific examples of the phosphoric ester plasticizer include the following: trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, tributoxyethyl phosphate, trioleyl phosphate , Triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, and the like. These plasticizers may be used alone or in combination of two or more.

  The resin composition of the present invention may contain an epoxy resin curing agent that does not contain a halogen element, if necessary, in addition to the above components as essential components. In this case, the blending ratio is 1 to 15% by weight, preferably 5 to 10% by weight, based on 100 parts by weight of the total of the polyimide resin and the epoxy resin. From another viewpoint, the range of 20 to 70% by weight of the epoxy resin is preferable. The use of the epoxy resin curing agent is effective when a silicon unit-containing polyimide resin that does not have the functional group represented by the general formula (3) in the molecule is used.

  Specific examples of the epoxy resin curing agent include phenols such as phenol novolak, o-cresol novolak, phenol resole, amines such as naphthols and diethylenetriamine, and acid anhydrides such as pyromellitic anhydride and phthalic anhydride. Can be mentioned.

In addition to the above-described components, the resin composition of the present invention may optionally contain a conventionally known curing accelerator not containing a halogen element, a coupling agent, a filler, a pigment, and the like. Moreover, other polyimide resins or other epoxy resins other than the silicon unit-containing polyimide resin or acenaphthylene- modified epoxy resin can be blended in a small amount as long as the effects of the present invention are not impaired.

  The flame-retardant adhesive resin composition of the present invention comprising the above components can be used in the form of a film. In this case, it can be formed into a film using a conventionally known method. As an example of a suitable molding method, a resin composed of a polyimide resin, an epoxy resin and a plasticizer component is dissolved in a solvent, and the obtained resin solution is used for a metal foil, a polyester film, a polyimide film, or the like whose surface is peeled off. There is a method of forming a flame-retardant adhesive film of the present invention (hereinafter also referred to as an adhesive film) by coating on a base material by a conventionally known method, drying and peeling from the base material.

  Typical examples of the solvent used in the film forming step include N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-diethylacetamide. Amide solvents such as N, N-dimethylmethoxyacetamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, tetrahydrofuran, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dioxane, γ-butyrolactone, xylenol, phenol, methyl cellosolve, ethyl cellosolve, Mention may be made of ethers, esters and alcohol solvents such as methyl cellosolve acetate, ethyl cellosolve acetate, toluene, xylene and methyl ethyl ketone. In addition, the solvent used at the time of forming the polyimide resin may be used as it is as the solvent for forming the film.

  As a suitable usage method of the flame-retardant adhesive film of the present invention, for example, a flexible printed wiring board, a glass fiber-epoxy wiring board, a paper-phenol wiring board, or various printed wiring boards obtained by processing these circuits, metal Suitable for adhesion of adherends such as resin base materials. A printed wiring board can be obtained by bonding a metal foil and a resin base material, and a multilayer printed wiring board or printed wiring board can be obtained by bonding printed wiring boards or printed wiring boards together. By bonding the board and the coverlay film, a printed wiring board with a coverlay can be obtained. In addition, it can be used as an adhesive film for connecting a printed wiring board or a printed wiring board. In any case, it is used in the process of manufacturing or processing a printed circuit board.

As a method of bonding using the flame retardant adhesive film of the present invention, an adhesive film is inserted between two adherends, and the temperature is 20 to 250 ° C. and the pressure is 1 to 100 kg / cm ² . And a method of forming an adhesive layer between the adherends by preferably heat-treating at a temperature of 50 to 250 ° C. for a predetermined time and completely curing the epoxy resin.

  The flame retardant adhesive resin composition of the present invention can also be applied to an adhesive layer of a coverlay film. In that case, although a coverlay film is formed from a base film and the said adhesive resin composition, the curvature as a film can be suppressed by mix | blending the said plasticizer within the said range.

  As a method of forming the coverlay film of the present invention, it is possible to form a film using a conventionally known method. As an example of a suitable molding method, the above resin composition is dissolved in a solvent, and the resulting resin solution is coated on a base film by a conventionally known method, and then dried, thereby covering the coverlay film of the present invention. There is a method. After coating the base film with a thickness of 2 to 200 μm, preferably 5 to 100 μm, more preferably 10 to 50 μm, 50 to 140 ° C., preferably 80 to 140 ° C., more preferably 100 to 140 ° C. It is possible to make a coverlay film by drying with. Although it will not specifically limit if it is an insulating resin film used as a coverlay film as a base film, A polyimide film is preferable in order to increase heat resistance and a flame retardance. The insulating resin film may have an appropriate thickness as required, but is preferably 3 to 50 μm, more preferably 5 to 30 μm.

  As a typical solvent used in the film forming step, those described above can be used in the same manner.

As a preferred method of using the coverlay film of the present invention, the coverlay film of the present invention is coated on the circuit board on which the conductor circuit is formed so that a desired portion of the conductor circuit is coated, and then the pressure is applied. An insulating coating can be formed by thermocompression bonding under conditions of 1 to 100 kg / cm ² and a temperature of 20 to 250 ° C.

  The adhesive resin composition and the coverlay film of the present invention can be thermocompression bonded at a lower temperature than conventional polyimide adhesives without impairing the inherent excellent heat resistance and electrical characteristics of polyimide. Excellent flame retardancy can be imparted without containing halogen elements, and there is little risk of the generation of harmful substances such as dioxins when discarded by incineration. Therefore, the flame retardant adhesive resin composition according to the present invention and the flame retardant adhesive film using the same are suitable for adhesives for multilayer printed circuit boards, adhesives for composite circuit boards, adhesives for coverlay films, etc. Can be used.

  Unless otherwise specified in the examples of the present invention, various measurements and evaluations are as follows.

[Measurement of tensile strength]
The tensile strength of the adhesive film and coverlay film was cut into a strip shape with a width of 12.5 mm and a length of 120 mm, and the crosshead speed was measured using a tensile tester (Toyo Seiki Co., Ltd., Strograph-R1). Measured under the conditions of 25 mm / min and a distance between chucks of 101.6 mm, and the value obtained by dividing the measured load by the cross-sectional area of the test piece (0.31 mm ² ) is the tensile strength.

[Measurement of glass transition temperature (Tg)]
The glass transition temperature of the adhesive film and the coverlay film was measured using a thermomechanical analyzer (Bruker, 4000SA), a test piece with a width of 2 mm and a length of 30 mm, a chuck distance of 15 mm, a load of 2 g, and a heating rate. The amount of thermal expansion in the length direction of the test piece is measured at 5 ° C./minute, and the inflection point is defined as the glass transition temperature (Tg).

[Measurement of adhesive strength]
1) Adhesive film The adhesive strength as an adhesive film was obtained by cutting a test piece into a width of 10 mm and a length of 100 mm using a tensile tester (Toyo Seiki Co., Ltd., Strograph-M1). After thermocompression bonding between glossy surfaces of two copper foils (35μm thick) and between two polyimide films (manufactured by Kaneka Corporation, Apical NPI) at 180 ° C for 60 minutes at 40kg / cm ² The force at the time of peeling at a speed of 50 mm / min in the 180 ° direction is defined as the adhesive strength. The adhesive strength 1 is the adhesive strength to the copper foil, and the adhesive strength 2 is the adhesive strength to the polyimide film.
2) Coverlay film Adhesive strength as a coverlay film was cut out to a width of 10mm and a length of 100mm using a tensile tester (Toyo Seiki Co., Ltd., Strograph-M1). Place the surface on a glossy surface of copper foil (35μm thickness) or a polyimide film (Kaneka Corporation, Apical NPI) and heat-press at 180 ° C for 60 minutes at 40kg / cm ² , then 180 ° The force when peeling in the direction at a speed of 50 mm / min is defined as the adhesive strength. The adhesive strength 1 is the adhesive strength to the copper foil, and the adhesive strength 2 is the adhesive strength to the polyimide film.

[Measurement of relative permittivity]
1) Adhesive film The relative dielectric constant of the adhesive film is measured at 180 ° C for 60 minutes at 40 kg / cm ² using an automatic dielectric loss measuring device (manufactured by Ando Electric Co., Ltd., TR-1100). JIS C-6481 electrode pattern was printed on both sides of the test piece with silver paste. The test piece after printing the electrode pattern is allowed to stand at 25 ° C. and 50% relative humidity for 24 hours, and the value obtained by measuring the relative dielectric constant at 1 Hz is taken as the relative dielectric constant.
2) Coverlay film The relative dielectric constant as a coverlay film was measured using a dielectric loss automatic measuring device (manufactured by Ando Electric Co., Ltd., TR-1100 type). The test piece was prepared by thermosetting a polyimide film (Akane NPI, Apical NPI, 100 mm × 100 mm × 25 μm thickness) at 180 ° C. for 60 minutes at 40 kg / cm ² . What used the electrode pattern of JIS C-6481 printed on both the adhesive agent surface and the polyimide film surface using the silver paste was used. The test piece is allowed to stand for 24 hours at 25 ° C. and a relative humidity of 50%, and the value obtained by measuring the relative permittivity at 1 Hz is defined as the relative permittivity.

[Measurement of volume resistivity]
The volume resistivity of the adhesive film and the coverlay film is a value measured based on JIS C-2330.

[Measurement of thermal decomposition temperature]
The thermal decomposition temperature of the adhesive film and the coverlay film is a value obtained by measuring a 5% weight loss temperature in a nitrogen atmosphere using TG / DTA6200 manufactured by SII.

[Method for evaluating solder heat resistance]
1) Adhesive film Solder heat resistance as an adhesive film was evaluated by sandwiching a test piece with a width of 10m and a length of 100mm between two glossy surfaces of copper foil (thickness 35μm) at 180 ° C for 60 minutes. What was thermocompression bonded under the conditions of 40 kg / cm ² was used. This test piece with copper foil was left for 24 hours at 25 ° C and 50% relative humidity, then immersed in a solder bath at 260 ° C for 60 seconds, and observed for adhesion, foaming, blistering, peeling, etc. Confirm by confirming.
2) Coverlay film Solder heat resistance of the coverlay film was evaluated by placing the adhesive side of a test piece with a width of 10m and a length of 100mm on the glossy surface of a piece of copper foil (thickness of 35μm). , 60 minutes, thermocompression bonded under the condition of 40 kg / cm ² was used. This test piece with copper foil was left for 24 hours at 25 ° C and 50% relative humidity, then immersed in a solder bath at 260 ° C for 60 seconds, and observed for adhesion, foaming, blistering, peeling, etc. Confirm by confirming.
Note that> 300 ° C. means that these defects are not recognized at 300 ° C. or lower.

[Flame retardancy evaluation method]
The flame retardancy was evaluated at a level indicating the degree of flame retardancy by a combustion test based on UL-94. VTM-0 means that there is flame retardancy, and the case where flame retardancy was not expressed was judged as NG.

EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, of course, this invention is not limited to this. In addition, the symbol used in the present Example shows the following compounds.
ODPA: 3,3 ', 4,4'-diphenyl ether tetracarboxylic dianhydride
DSDA: 3,3 ', 4,4'-diphenylsulfonetetracarboxylic dianhydride
BTDA: 3,3 ', 4,4'-benzophenone tetracarboxylic dianhydride
BPDA: 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride
BAPP: 2,2'-bis (4-aminophenoxyphenyl) propane
mBAPS : bis (3-aminophenoxyphenyl) sulfone
BisAM: 1,3-bis (aminoisopropyl) benzene
HAB: 4,4 '-(3,3'-dihydroxy) diaminobiphenyl
HFP : 2,2′-bis (3-amino-4-hydroxyphenyl) hexafluoropropane
TCP: tricresyl phosphate
PSX-A , PSX-B, PSX-C and PSX-D: Diaminosiloxane represented by the following formula (8) (however, the average m number is in the range of 1 to 20, and the average molecular weight of PSX-A is 740) PSX-B has an average molecular weight of 1000, PSX-C has an average molecular weight of 1240, and PSX-D has an average molecular weight of 2000.)
PSX-Ph: diaminosiloxane represented by the following formula (9) (however, the total number of j and n is in the range of 2 to 20, j and n are both 1 or more, and the average molecular weight is 1320)
NA resin: 1-naphthol aralkyl resin represented by the following formula (10) (SN-485 manufactured by Nippon Steel Chemical Co., Ltd.)

Synthesis example 1
In a 500 ml separable flask, 180 g of NA resin and 20 g of acenaphthylene were used and stirred at 100 ° C. for 1 hour to carry out an addition reaction to obtain 200 g of acenaphthylene-modified naphthol aralkyl resin. The softening point of the obtained acenaphthylene-modified naphthol aralkyl resin was 54 ° C. as measured according to JIS K 2548, and the hydroxyl equivalent (OH equivalent) was 236. The addition reaction rate of acenaphthylene by GPC was 99%, and the substitution rate of acenaphthenyl group (number of moles of acenaphthylene added per mole of naphthalene ring) was 0.4.

Synthesis example 2
Next, 100 g of the acenaphthylene-modified naphthol aralkyl resin thus obtained was dissolved in 400 g of epichlorohydrin, and 40 g of 50% aqueous sodium hydroxide solution was added over 4 hours while reducing the pressure to 100 mmHg at 60 ° C. for 5 hours. Reacted. During this reaction, the produced water was removed out of the system by azeotropy with epichlorohydrin.
After completion of the reaction, after completion of the reaction, excess epichlorohydrin was distilled off under reduced pressure. 450 g of methyl isobutyl ketone was added to the residue to dissolve the epoxy resin, followed by filtration under reduced pressure, and the epoxy resin was recovered from the filtrate. Thereafter, 20 g of a 20% aqueous sodium hydroxide solution was added, and the mixture was reacted at 80 ° C. for 2 hours. Subsequently, filtration and washing were performed, and methyl isobutyl ketone was distilled off under reduced pressure to obtain 120 g of brown acenaphthylene-modified naphtholic epoxy resin (modified resin A). The resulting modified resin A had a softening point of 48 ° C. and an epoxy equivalent of 308.

Synthesis example 3
To a 500 ml separable flask, add 160 g of phenol aralkyl resin (MEH-7800-4L, Meiwa Kasei Co., Ltd., OH equivalent 162), melt at 100 ° C., add 40 g of acenaphthylene, stir at 100 ° C. for 1 hour, The addition reaction was performed to obtain 198 g of acenaphthylene-modified phenolic resin. The softening point of the obtained acenaphthylene-modified phenol aralkyl resin was 59 ° C. as a result of measurement according to JIS K 2548, and the hydroxyl equivalent (OH equivalent) was 184. The addition reaction rate of acenaphthylene by GPC was 99%, and the substitution rate of acenaphthenyl group was 0.4.

Synthesis example 4
Next, 100 g of the acenaphthylene-modified phenol aralkyl resin thus obtained was dissolved in 400 g of epichlorohydrin, and 40 g of a 50% aqueous sodium hydroxide solution was added over 4 hours while reducing the pressure to 100 mmHg at 60 ° C. for 5 hours. Reacted. During this reaction, the produced water was removed out of the system by azeotropy with epichlorohydrin.
After completion of the reaction, after completion of the reaction, excess epichlorohydrin was distilled off under reduced pressure. 450 g of methyl isobutyl ketone was added to the residue to dissolve the epoxy resin, followed by filtration under reduced pressure, and the epoxy resin was recovered from the filtrate. Thereafter, 20 g of a 20% aqueous sodium hydroxide solution was added, and the mixture was reacted at 80 ° C. for 2 hours. Subsequently, filtration and washing were carried out, and methyl isobutyl ketone was distilled off under reduced pressure to obtain 116 g of brown acenaphthylene-modified phenolic epoxy resin (modified resin B). The resulting modified resin B had a softening point of 52 ° C. and an epoxy equivalent of 303.

Synthesis example 5
In a 500 ml separable flask, 180 g of NA resin and 39 g of indene were used and stirred at 100 ° C. for 1 hour, followed by addition reaction to obtain 218 g of naphthol aralkyl resin substituted with indenyl group. The softening point of the obtained indene-modified naphthol aralkyl resin was 107 ° C. as measured according to JIS K 2548, and the hydroxyl group equivalent (OH equivalent) was 261. The addition reaction rate of indene by GPC was 99%, and the indenyl group substitution rate was 0.4.

Synthesis Example 6
Next, 100 g of the indenyl-modified naphthol aralkyl resin thus obtained was dissolved in 285 g of epichlorohydrin, and 35 g of a 50% aqueous sodium hydroxide solution was added over 4 hours, while reducing the pressure at 100 mmHg for 5 hours at 60 ° C. Reacted. During this reaction, the produced water was removed out of the system by azeotropy with epichlorohydrin.
After completion of the reaction, after completion of the reaction, excess epichlorohydrin was distilled off under reduced pressure, 285 g of methyl isobutyl ketone was added to the residue to dissolve the epoxy resin, and sodium chloride was removed by washing with water. Thereafter, 20 g of a 20% aqueous sodium hydroxide solution was added, and the mixture was reacted at 80 ° C. for 2 hours. Subsequently, filtration and washing were performed, and methyl isobutyl ketone was distilled off under reduced pressure to obtain 110 g of a brown indene-modified naphtholic epoxy resin (INPT). The resulting INPT had a softening point of 95 ° C. and an epoxy equivalent of 320.

Synthesis example 7
Using a 500 ml separable flask, 180 g of NA resin and 35 g of styrene were stirred at 140 ° C. for 1 hour, and an addition reaction was carried out to obtain 213 g of a styrenyl-substituted naphthol aralkyl resin. The softening point of the obtained styrene-modified naphthol aralkyl resin was 88 ° C as measured according to JIS K 2548, and the hydroxyl equivalent (OH equivalent) was 258. Further, the addition reaction rate of styrene by GPC was 99%, and the substitution rate of styryl group was 0.4.

Synthesis Example 8
Next, 100 g of the styrene-modified naphthol aralkyl resin thus obtained was dissolved in 290 g of epichlorohydrin, and 36 g of a 50% aqueous sodium hydroxide solution was added over 4 hours, while reducing the pressure at 100 mmHg for 5 hours at 60 ° C. Reacted. During this reaction, the produced water was removed out of the system by azeotropy with epichlorohydrin.
After completion of the reaction, excess epichlorohydrin was distilled off under reduced pressure, 285 g of methyl isobutyl ketone was added to the residue to dissolve the epoxy resin, and sodium chloride was removed by washing with water. Thereafter, 20 g of a 20% aqueous sodium hydroxide solution was added, and the mixture was reacted at 80 ° C. for 2 hours. Subsequently, filtration and washing were performed, and methyl isobutyl ketone was distilled off under reduced pressure to obtain 109 g of a brown styrene-modified naphthol epoxy resin (STNPT). The obtained STNPT had a softening point of 75 ° C. and an epoxy equivalent of 317.

Synthesis Example 9
A 1000 ml separable flask was charged with 50.16 g DSDA (0.14 mol), 200 g N-methyl-2-pyrrolidone and 200 g xylene and mixed well at room temperature, then 31.54 g PSX using a dropping funnel. -A (0.0434 mol) was added dropwise, the reaction solution was ice-cooled with stirring, 37.36 g of BAPP (0.091 mol) and 1.30 g of HAB (0.006 mol) were added, and the mixture was stirred at room temperature for 2 hours. A polyamic acid solution was obtained. This polyamic acid solution was heated to 190 ° C., heated and stirred for 20 hours to obtain a polyimide solution a having a logarithmic viscosity of 0.9 dl / g.

Synthesis Examples 10 to 21
A polyimide solution b to m was prepared in the same manner as in Example 1 except that the raw material composition shown in Table 1 was used.

Example 1
30 parts by weight of the modified resin A obtained in Synthesis Example 2 was mixed with 70 parts by weight of the solid content of the polyimide solution a obtained in Synthesis Example 9. Furthermore, 30 parts by weight of TCP was mixed with 100 parts by weight of a mixed resin of a polyimide resin having a siloxane unit and an epoxy resin, and stirred at room temperature for 2 hours to prepare an adhesive resin (resin composition) solution. This resin solution was applied on a glass plate, dried to form a film, and an adhesive film was obtained. The glass transition temperature of this film was 185 ° C. The film had a tensile strength of 74 MPa, a relative dielectric constant of 2.9, a volume resistivity of 2 × 10 ¹⁵ Ωcm, an adhesive strength of 1.4 kN / m, and a thermal decomposition temperature of 460 ° C. Also, the solder heat resistance was good, with no defects such as blistering and peeling being observed. The results are shown in Tables 2 and 3.

Example 2
Using the polyimide solution b obtained in Synthesis Example 10, a resin composition was prepared with the composition shown in Table 2, and a film was formed in the same manner as in Example 1. Tables 2 and 3 show the results of measuring the various characteristics.

Example 3
30 parts by weight of the modified resin A obtained in Synthesis Example 2 was mixed with 70 parts by weight of the solid content of the polyimide solution a obtained in Synthesis Example 9. Furthermore, 30 parts by weight of TCP was mixed with 100 parts by weight of a mixed resin of a polyimide resin having a siloxane unit and an epoxy resin, and stirred at room temperature for 2 hours to prepare an adhesive resin composition solution. This resin solution was applied on a polyimide film (manufactured by Kaneka Corporation, Apical NPI, 100 mm × 100 mm × 25 μm thickness) to a thickness of 25 μm and dried to obtain a coverlay film.
The glass transition temperature of this coverlay film was 175 ° C. The coverlay film had a tensile strength of 170 MPa, a relative dielectric constant of 3.2, a volume resistivity of 1.4 × 10 ¹⁵ Ωcm, an adhesive strength of 0.8 kN / m, and a thermal decomposition temperature of 370 ° C. Also, the solder heat resistance was good, with no defects such as blistering and peeling being observed. The results are shown in Tables 2 and 3.
The coverlay film here refers to an adhesive resin composition with a polyimide film.

Examples 4-13
A polyimide solution was prepared in the same manner as in Example 1 with the composition shown in Table 1, a resin composition was prepared with the composition shown in Table 1, and a coverlay film was formed. Tables 2 and 3 show the results of measuring the various characteristics. When an epoxy resin curing agent was used, a naphthol resin (ESN-485 manufactured by Toto Kasei Co., Ltd.) was used as the epoxy resin curing agent. As the epoxy resin, the acenaphthylene-modified naphtholic epoxy resin (modified resin A) obtained in Synthesis Example 2 was used.

Comparative Examples 1-10
In the same manner as in the examples, a polyimide solution was prepared with the composition shown in Table 1, a resin composition was prepared with the composition shown in Table 1, and a coverlay film was formed. Tables 2 and 3 show the results of measuring various characteristics of the coverlay film.

  In Table 2, DGEBA is an epoxy resin obtained by glycidyl etherification of bisphenol A, oCNB is an epoxy resin obtained by glycidyl etherification of o-kuzol novolac resin, and INPT is an indene-modified naphthol property substituted with indene. Epoxy resin, STNPT, is a styrene-modified naphtholic epoxy resin substituted with styrene. A is the modified resin A obtained in Synthesis Example 2, and B is the modified resin B obtained in Synthesis Example 4. The results are shown in Tables 2 and 3.

Comparative Examples 11-14
Except for blending 50 parts by weight of TCP (Comparative Example 11) and not blending TCP (Comparative Example 12), the same procedure as in Example 1 was performed. The results are shown in Tables 2 and 3.

The warpage in Table 3 judged the state of the obtained coverlay film.
None: A state in which warpage is not recognized and can be used.
NG: Indicates that curling or curling is difficult and is difficult to use.

Claims (8)

The following general formula (1) and the following general formula (2)

(In General Formula (1), Ar ₁ represents a tetravalent aromatic group, R ₁ and R ₂ represent a divalent hydrocarbon group, and R ₃ and R ₄ represent a monovalent monovalent group having 1 to 6 carbon atoms. Represents a hydrocarbon group, and m represents a number from 1 to 20. In the general formula (2), Ar ₁ represents a tetravalent aromatic group, and Ar ₂ represents a divalent aromatic group.
The constitutional ratio of the repeating units represented by the general formulas (1) and (2) is (1) / (2) = 50/50 to 10/90 (molar ratio). Silicon unit-containing polyimide resin in the range of 65 to 98% by weight, and the following general formula (4)

(However, A represents a naphthalene nucleus, G represents a glycidyl group, R represents an acenaphthenyl group or hydrogen, X represents an alkylene group or an aralkylene group represented by -Y-Ar-Y-, and p represents 0. Represents a number of ˜15, q represents 1 or 2, and the proportion of acenaphthenyl group in R is 10 mol% or more, Y represents an alkylene group, and Ar represents a divalent aromatic group. Show.)
1 to 45 parts by weight of a phosphoric ester plasticizer having a molecular weight of 1000 or less is mixed with 100 parts by weight of a mixed resin composed of 2 to 35% by weight of an acenaphthylene-modified epoxy resin having a structure represented by : A flame retardant adhesive resin composition substantially free of halogen elements.   2. The flame retardant adhesive resin composition according to claim 1, wherein the flame retardant adhesive resin composition is formed from a resin composition further containing 1 to 15 parts by weight of an epoxy resin curing agent with respect to a total of 100 parts by weight of the silicon unit-containing polyimide resin and the acenaphthylene-modified epoxy resin. object. 1 to 20 mol% of Ar ₂ in the general formula (2) is represented by the following general formula (3)

(However, Ar ₃ represents a trivalent or tetravalent aromatic group, X represents a hydroxyl group, an amino group, a carboxyl group, or a mercapto group, and k represents 1 or 2)
The flame retardant adhesive resin composition according to claim 1, which is a divalent aromatic group having a functional group reactive with an epoxy group represented by the formula: The flame-retardant adhesive resin composition according to any one of claims 1 to 3, wherein the acenaphthylene-modified epoxy resin is an epoxy resin having a structure represented by the following general formula (5) .

(Where, A is a naphthalene nucleus, G is a glycidyl group, R _5, R ₆ and R ₈ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R ₇ is represented by the following formula (a) An acenaphthenyl group or hydrogen, wherein 10 mol% or more is an acenaphthenyl group, p is a number from 0 to 15, and q is 1 or 2.

A flame retardant adhesive film, wherein the flame retardant adhesive resin composition according to claim 1 is formed into a film. The flame-retardant adhesive film according to claim 5 is inserted between objects to be bonded, and a pressure of 1 to 100 kg / cm. ² A method of using a flame retardant adhesive film, wherein the film is used by thermocompression bonding under conditions of a temperature of 20 to 250 ° C. A coverlay film formed from a base film and an adhesive resin composition, wherein the adhesive resin composition is the flame retardant adhesive resin composition according to any one of claims 1 to 4. Coverlay film. The cover lay film according to claim 7 is coated on a circuit board on which a conductor circuit is formed so that a desired portion of the conductor circuit is coated, and then a pressure of 1 to 100 kg / cm. ² A method for producing a circuit board, comprising forming an insulating film by thermocompression bonding under conditions of a temperature of 20 to 250 ° C.