KR20210022631A - Adhesive composition containing acrylonitrile butadiene rubber copolymer polyamide imide resin - Google Patents

Abstract

Provides an adhesive composition having improved adhesion, insulation reliability, flame retardancy, and B-stage adhesive film embrittlement resistance, improved humidification solder heat resistance, and excellent spillability and B-stage adhesive film temporary adhesiveness. (A1) polyamide imide resin not containing acrylonitrile butadiene rubber; (A2) acrylonitrile butadiene rubber copolymerized polyamide imide resin; And (B) an epoxy resin having two or more epoxy groups per molecule to form a homogeneous phase, wherein (i) the mass ratio of A1/A2 in the composition is 0.1 or more and 1.0 or less; (ii) the mass ratio of (A1+A2)/B in the composition is 0.9 or more and 3.6 or less; (iii) (A2) is a copolymer comprising (a) a polycarboxylic acid derivative having an acid anhydride group, (b) an isocyanate compound or an amine compound, and (c) an acrylonitrile-butadiene rubber having a carboxyl group at both ends. It is a resin, and the ratio of the structural units derived from each acid component in the case of 100 mol% of the constituent units derived from the total acid components in (A2) is (a) 90 to 99 mol%, (c) 1 to 5 mol %to be.

Description

Adhesive composition containing acrylonitrile butadiene rubber copolymer polyamide imide resin

The present invention relates to an adhesive composition comprising an acrylonitrile butadiene rubber copolymerized polyamide imide resin, and more specifically, excellent adhesion, heat resistance, insulation, flexibility, flame retardancy, fluidity, coverlay film, adhesive film, It relates to an adhesive composition suitable for a three-layer copper clad laminate or the like.

In general, flexible printed wiring boards (hereinafter, also referred to as FPCs) are applied to wiring board materials and mounting board materials for electronic devices that require flexibility and small space. For example, it is widely used in device mounting boards for display devices used in liquid crystal displays, plasma displays, organic EL displays, etc., relay cables between boards such as smart phones, tablet device terminals, digital cameras, and portable game machines, and operation switch boards. .

In recent years, as electronic devices become smaller, thinner, and highly functional, electronic circuits have been highly integrated, and in addition to the smaller and thinner FPCs, the demand for multilayer FPCs in which a single layer of FPC is laminated with an interlayer adhesive is increasing. Therefore, even for the coverlay (hereinafter also referred to as CL) of the FPC and the adhesive used between layers, higher adhesiveness, insulation reliability, humidification solder heat resistance, and the like are required.

As a measure for improving the humidification solder heat resistance, it is generally considered to reduce the water absorption of the resin composition by reducing the polarity of the resin. However, since the adhesiveness to the circuit material (copper foil) decreases when the resin polarity is decreased, there is a problem that it is difficult to achieve both of these characteristics.

By the way, the adhesive used for FPC is a circuit such as copper foil and polyimide film from the release film after the B-stage adhesive film obtained by applying a liquid resin composition on a release film and volatilizing a solvent is wound up in a roll shape. It is used by temporary bonding to the material and thermocompression bonding.

Therefore, in the winding process of the B-stage adhesive film, flexibility is required so as not to cause cracks in the adhesive film. In addition, when the B-stage adhesive film is temporarily bonded to the circuit material, by providing temporary-adhesion to the B-stage adhesive film, the roll-to-roll FPC production becomes possible, and productivity can be significantly improved. In addition, in the thermocompression bonding process, it is required that the amount of the adhesive outflow from the CL end is small.

As a resin used for CL and the interlayer insulating layer, a closed cyclic polyimide resin has been proposed which is excellent in heat resistance, insulation and chemical resistance, and is solvent-soluble. However, in general, since a high boiling point solvent such as N-methyl-2-pyrrolidone is used as a solvent for a wholly aromatic polyimide resin varnish polymerized only with an aromatic monomer, drying/curing In this case, a curing process at a high temperature of 200°C or higher for a long time is required, and there is a problem that thermal deterioration of the electronic component occurs.

In addition, since the wholly aromatic polyimide resin generally has a high glass transition temperature, there is a problem that the embedding property is deteriorated when the adhesive is thermocompressed to a substrate such as a polyimide film or copper foil, and the adhesive strength is lowered.

On the other hand, in order to solve the problem of such a decrease in adhesiveness, a polysiloxane-modified polyimide resin has been disclosed (see, for example, Patent Documents 1 and 2).

In addition, for improving the solvent solubility in a low boiling point solvent, a method of copolymerizing acrylonitrile butadiene having a reactive functional group with a wholly aromatic polyamide-imide resin having excellent solvent solubility has been proposed (for example, see Patent Document 3). ).

However, the polysiloxane-modified polyimide resin described in Patent Literatures 1 and 2 uses diamine having an expensive dimethylsiloxane bond as a starting material, and is therefore inferior in economic efficiency. In addition, there is a problem that adhesiveness decreases with an increase in the amount of polysiloxane copolymerization. In addition, in the polyamide-imide resin described in Patent Document 3, it is necessary to increase the copolymerization amount of acrylonitrile butadiene, and as a result, there is a concern that the insulation reliability may decrease.

Patent Document 1: Japanese Patent Laid-Open Publication No. Hei 7-304950 Patent Document 2: Japanese Patent Laid-Open No. 8-333455 Patent Document 3: Japanese Patent Laid-Open No. 2003-289594

The present invention has been made against the background of these prior art problems, and its purpose is to improve (1) adhesiveness, (2) insulation reliability, (3) flame retardancy, and (4) B-stage adhesive film embrittlement resistance equivalent to conventional products. Provides an adhesive composition having (5) improved humidification solder heat resistance, and (6) spillability, and (7) B-stage adhesive film temporary adhesiveness, and in particular, an electronic component having an interlayer insulating layer or an adhesive layer It is to provide an adhesive composition suitable for use in the.

The inventors of the present invention found that, as a result of earnestly examining in order to achieve the above object, an adhesive composition that forms a homogeneous phase while containing a specific component as an essential component in a specific ratio has the characteristics of (1) to (7) above. The present invention has been completed.

That is, the present invention has the following configurations (1) to (6).

(1) (A1) Polyamide imide resin not containing acrylonitrile butadiene rubber;

(A2) acrylonitrile butadiene rubber copolymerized polyamide imide resin; And

(B) An adhesive composition characterized by containing an epoxy resin having two or more epoxy groups per molecule as an essential component to form a homogeneous phase, and satisfying the following conditions (i) to (iii):

(i) the mass ratio of A1/A2 in the composition is 0.1 or more and 1.0 or less;

(ii) the mass ratio of (A1+A2)/B in the composition is 0.9 or more and 3.6 or less;

(iii) When (A2) is a resin containing the following components (a), (b) and (c) as a copolymerization component, and the structural units derived from the total acid components of (A2) are 100 mol% The proportion of the constituent units derived from the acid component is (a) 90-99 mol%, (c) 1-5 mol%:

(a) a polycarboxylic acid derivative having an acid anhydride group;

(b) an isocyanate compound or an amine compound;

(c) Acrylonitrile-butadiene rubber having carboxyl groups at both ends.

(2) The valence of the polycarboxylic acid derivative of the component (a) is trivalent and/or tetravalent, the weight average molecular weight of the component (c) is 500 to 5000, and the proportion of the acrylonitrile moiety is 10 to 50 mass. The adhesive composition according to (1), characterized in that it is in the range of %.

(3) The adhesive composition according to (2), wherein (a) is a polycarboxylic acid derivative having an aromatic ring, and (b) is a diisocyanate compound having an aromatic ring or a diamine compound having an aromatic ring.

(4) The adhesive composition according to any one of (1) to (3), wherein the molecular weight (Mc) between crosslinking points determined by the following formula when thermally cured at 170°C for 3 hr is 2000 or less:

Molecular weight between crosslinking points (Mc) = 3ρRT×1000000/E'

However, R = 8.31 [Jmol ^-1 K ^-1 ], E'and T are determined by dynamic viscoelasticity measurement, and ρ is determined by specific gravity measurement.

(5) The adhesive composition according to any one of (1) to (4), further comprising a phosphorus-based flame retardant (C).

(6) The adhesive composition according to any one of (1) to (5), wherein the numerical value obtained by the following formula is 1.5 or more and 7.0 or less:

Compounding ratio of epoxy resin solid content (parts by mass) to adhesive solid content (parts by mass) × epoxy equivalent [eq/t]/(polyamide imide resin (A1) solid content (parts by mass) to adhesive solid content (parts by mass)) Blending ratio × acid value of polyamide imide resin (A1) [eq/t] + NBR copolymerized polyamide imide resin (A2) solid content (parts by mass) to adhesive solid content (parts by mass) × NBR copolymerized polyamide The compounding ratio of the acid value of the imide resin (A2) [eq/t] + the solid content of the compound having a phenolic hydroxyl group to the solid content of the adhesive (parts by mass) × phenolic hydroxyl value [eq/t]}.

The adhesive composition of the present invention has (1) adhesiveness, (2) insulation reliability, (3) flame retardancy, (4) B-stage adhesive film embrittlement resistance, which is equivalent to that of conventional products, while (5) improving humidification solder heat resistance. Also, (6) outflow property and (7) B-stage adhesive film are excellent in temporary adhesiveness, so they can be suitably used in an electronic component having an interlayer insulating layer or an adhesive layer.

Hereinafter, the adhesive composition of the present invention will be described in detail. The adhesive composition of the present invention is a resin composition that forms a homogeneous phase while containing a specific component as an essential component in a specific ratio, and is a polyamide imide resin (A1) that does not contain an acrylonitrile butadiene rubber, and an acrylonitrile butadiene rubber. It contains a copolymerized polyamide imide resin (A2) and an epoxy resin (B) having two or more epoxy groups per molecule, and more preferably contains a phosphorus-based flame retardant (C).

<Polyamide imide resin (A1)>

The polyamide imide resin (A1) of the present invention is not particularly limited as long as it can achieve the object of the present invention, but (a) a trivalent and/or tetravalent polycarboxylic acid derivative having an acid anhydride group, (b ) It is preferable that it is a resin which uses an isocyanate compound or an amine compound as a copolymerization component. As for the polyamide imide resin (A1) of this invention, it is preferable that Tg is 160 degreeC or more resin.

The polyamide imide resin (A1) of the present invention is a polyamide imide resin that does not contain acrylonitrile butadiene rubber, and therefore, it is excellent in heat resistance and insulation reliability. In addition, the polyamide imide resin (A1) is compatible with the acrylonitrile butadiene rubber copolymer polyamide imide resin (A2) to be described later to form a homogeneous phase, thereby forming an acrylonitrile butadiene rubber copolymer polyamide imide resin ( Insulation reliability of A2) can be improved. Moreover, since the acid value which becomes the crosslinking point with the epoxy resin (B) which is a hardening|curing agent is high, the crosslinking density of the coating film after thermosetting becomes high, and humidification solder heat resistance can be improved. Further, when the Tg is 160°C or higher, it is possible to suppress outflow during thermocompression bonding.

In addition, the polyamide imide resin (A1) and (A2) generate a hydroxyl group when crosslinking with the epoxy resin (B). In particular, the polyamide imide resin (A1) has a high acid value as a crosslinking point with the epoxy resin (B), so that more hydroxyl groups are generated during thermal curing. Since this hydroxyl group improves the affinity with ACF, the polyamide imide resin (A1) can improve the ACF adhesion.

Whether the morphology of the adhesive composition is in a uniform phase or phase separation can be determined as follows by the domain size when the pre-treated adhesive composition is observed with a JEM2100 transmission electron microscope manufactured by Nihon Denshi under conditions of an acceleration voltage of 200 kV.

Homogeneous phase: adhesive composition does not contain domains greater than 0.1 μm

Phase separation: adhesive composition contains 0.1 μm or more domains

Under the condition that the weight ratio of A1/A2 in the adhesive composition is 0.1 or more and 1.0 or less, when the adhesive composition forms a phase-separated structure of sea islands, the island component is a polyamide imide resin that does not contain acrylonitrile butadiene rubber ( A1), and the sea component contains acrylonitrile butadiene rubber copolymerized polyamide imide resin (A2). Therefore, the morphology of the adhesive composition depends on the compatibility of (A1) not containing acrylonitrile butadiene rubber and the polyamide imide resin (A2) containing acrylonitrile butadiene rubber, and the acrylic contained in (A2) As the mass of the ronnitrile butadiene rubber decreases or the mass ratio of A1/A2 decreases, the compatibility between (A1) and (A2) improves, and the adhesive composition tends to form a homogeneous phase.

As described above, the polyamide imide resin (A1) is preferably a resin having a glass transition temperature of 160°C or higher, and a polycarboxyl having an aromatic ring when the structural unit derived from the total acid component is 100 mol%. It is preferable that it is a resin with at least 90 mol% of an anhydride of the acid. The blending amount of the polyamide imide resin (A1) is preferably 10 to 99 parts by mass, more preferably 20 to 90 parts by mass based on 100 parts by mass of the acrylonitrile butadiene rubber copolymerized polyamide imide resin (A2). to be. That is, the mass ratio of A1/A2 in the composition is preferably 0.1 or more and 1.0 or less, and more preferably 0.2 or more and 0.9 or less. When the blending amount is less than the above, it is difficult to obtain the effect of reducing leakage and improving the humidified solder, and in many cases, the adhesiveness is lowered. Regarding the compatibility, when the adhesive composition forms a phase-separated structure of the islands due to a decrease in compatibility, it is difficult to obtain an effect of improving the insulation reliability of the acrylonitrile butadiene rubber copolymerized polyamide imide resin (A2).

<Acrylonitrile butadiene rubber copolymerized polyamide imide resin (A2)>

The acrylonitrile butadiene rubber (hereinafter also referred to as NBR) copolymerized polyamide imide resin (A2) of the present invention includes (a) a polycarboxylic acid derivative having an acid anhydride group, (b) an isocyanate compound or an amine compound, and (c ) It is a resin containing an acrylonitrile butadiene rubber having a carboxyl group at both ends as a copolymerization component.

<(a) Polycarboxylic acid derivative having an acid anhydride group>

The component (a) constituting the polyamide imide resin (A1) and NBR copolymerized polyamide imide resin (A2) of the present invention is an acid anhydride group that reacts with an isocyanate component or an amine component to form a polyimide resin. It is a polycarboxylic acid derivative (hereinafter, also simply referred to as component (a)), and for example, an aromatic polycarboxylic acid derivative, an aliphatic polycarboxylic acid derivative, or an alicyclic polycarboxylic acid derivative can be used. Further, the valence of the polycarboxylic acid derivative is not particularly limited, but may generally be trivalent and/or tetravalent.

Although it does not specifically limit as an aromatic polycarboxylic acid derivative, For example, trimellitic anhydride, pyromellitic dianhydride, ethylene glycol bis anhydro trimellitate, propylene glycol bis anhydro trimellitate, 1,4-butanediol Alkylene glycol bis anhydrotrimelitate, such as bis anhydrotrimellitate, hexamethylene glycol bis anhydrotrimellitate, polyethylene glycol bis anhydrotrimellitate, and polypropylene glycol bis anhydrotrimellitate, 3,3 '-4,4'-benzophenonetetracarboxylic dianhydride, 3,3'-4,4'-biphenyltetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1, 4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,5,6-pyridine tetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 3,3',4 ,4'-diphenylsulfone tetracarboxylic dianhydride, m-terphenyl-3,3',4,4'-tetracarboxylic dianhydride, 4,4'-oxydiphthalic dianhydride, 1,1,1 ,3,3,3-hexafluoro-2,2-bis(2,3- or 3,4-dicarboxyphenyl)propanedianhydride, 2,2-bis(2,3- or 3,4-di Carboxyphenyl)propanedianhydride, 2,2-bis[4-(2,3- or 3,4-dicarboxyphenoxy)phenyl]propanedianhydride, 1,1,1,3,3,3-hexafluoro Rho-2,2-bis[4-(2,3- or 3,4-dicarboxyphenoxy)phenyl]propanedianhydride, or 1,3-bis(3,4-dicarboxyphenyl)-1,1 ,3,3-tetramethyldisiloxane dianhydride, etc. are mentioned.

Although it does not specifically limit as an aliphatic or alicyclic polycarboxylic acid derivative, For example, butane-1,2,3,4-tetracarboxylic dianhydride, pentane-1,2,4,5-tetracarboxylic dianhydride , Cyclobutanetetracarboxylic dianhydride, hexahydropyromellitic dianhydride, cyclohexa-1-ene-2,3,5,6-tetracarboxylic dianhydride, 3-ethylcyclohexa-1-ene-3- (1,2),5,6-tetracarboxylic dianhydride, 1-methyl-3-ethylcyclohexane-3-(1,2),5,6-tetracarboxylic dianhydride, 1-methyl-3- Ethylcyclohexa-1-ene-3-(1,2),5,6-tetracarboxylic dianhydride, 1-ethylcyclohexane-1-(1,2),3,4-tetracarboxylic dianhydride, 1-propylcyclohexane-1-(2,3),3,4-tetracarboxylic dianhydride, 1,3-dipropylcyclohexane-1-(2,3),3-(2,3)-tetra Carboxylic dianhydride, dicyclohexyl-3,4,3',4'-tetracarboxylic dianhydride, bicyclo[2,2,1]heptane-2,3,5,6-tetracarboxylic dianhydride, 1-propylcyclohexane-1-(2,3),3,4-tetracarboxylic dianhydride, 1,3-dipropylcyclohexane-1-(2,3),3-(2,3)-tetra Carboxylic dianhydride, dicyclohexyl-3,4,3',4'-tetracarboxylic dianhydride, bicyclo[2,2,1]heptane-2,3,5,6-tetracarboxylic dianhydride, Bicyclo[2,2,2]octane-2,3,5,6-tetracarboxylic dianhydride, bicyclo[2,2,2]octo-7-ene-2,3,5,6-tetracar Acid dianhydride, hexahydrotrimelitic anhydride, and the like.

These polycarboxylic acid derivatives having an acid anhydride group may be used alone or in combination of two or more. Considering the humidification solder heat resistance, adhesion, solubility, cost, etc., pyromellitic anhydride, trimellitic anhydride, ethylene glycolbisanhydrotrimellitate, 3,3'-4,4'-benzophenonetetracarboxyl Acid dianhydride and 3,3',4,4'-biphenyltetracarboxylic dianhydride are preferable, and trimellitic anhydride and ethylene glycolbisanhydrotrimellitate are more preferable.

The copolymerization amount of the component (a) in the polyamide imide resin (A1) or the NBR copolymerized polyamide imide resin (A2) needs to be 90 mol% when the total acid component to be reacted is 100 mol%. , It is preferably 91 mol% or more. If it is less than the above range, humidification solder heat resistance and insulation reliability may not be obtained. The upper limit of the copolymerization amount of the component (a) is up to 99 mol% in consideration of the balance with the component (c).

<(b) an isocyanate compound or an amine compound>

The component (b) constituting the NBR copolymerized polyamide imide resin (A2) of the present invention is not particularly limited as long as it is an isocyanate compound or an amine compound (hereinafter, also simply referred to as component (b)), and for example, aromatic polyisocyanate, aliphatic Polyisocyanates, alicyclic polyisocyanates, or polyamines corresponding thereto. Preferably, aromatic polyisocyanates or aromatic polyamines are used. The aromatic polyisocyanate is not particularly limited, but, for example, diphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3'- or 5 ,2'- or 5,3'- or 6,2'- or 6,3'-dimethyldiphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2 '- or 4,3'- or 5,2'- or 5,3'- or 6,2'- or 6,3'-diethyldiphenylmethane-2,4'-diisocyanate, 3,2' -Or 3,3'- or 4,2'- or 4,3'- or 5,2'- or 5,3'- or 6,2'- or 6,3'-dimethoxydiphenylmethane-2 ,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-3,3'-diisocyanate, diphenylmethane-3,4'-diisocyanate, diphenylether-4,4 '-Diisocyanate, benzophenone-4,4'-diisocyanate, diphenylsulfone-4,4'-diisocyanate, tolylene-2,4-diisocyanate, tolylene-2,6-diisocyanate, m- Xylylenediisocyanate, p-xylylenediisocyanate, naphthalene-2,6-diisocyanate, 4,4'-[2,2 bis(4-phenoxyphenyl)propane]diisocyanate, 3,3' or 2, 2'-dimethylbiphenyl-4,4'-diisocyanate, 3,3'- or 2,2'-diethylbiphenyl-4,4'-diisocyanate, 3,3'-dimethoxybiphenyl-4 , 4'-diisocyanate, 3,3'-diethoxybiphenyl-4,4'-diisocyanate, and the like. Considering heat resistance, adhesion, solubility, and cost, diphenylmethane-4,4'-diisocyanate, tolylene-2,4-diisocyanate, m-xylylenediisocyanate, 3,3'- or 2, 2'-dimethylbiphenyl-4,4'-diisocyanate is preferable, and 3,3'-dimethylbiphenyl-4,4'-diisocyanate and tolylene-2,4-diisocyanate are more preferable. These can be used alone or in combination of two or more. In addition, when an aromatic polyamine is used, a polyamine corresponding to the aromatic polyisocyanate can be used.

<(c) Acrylonitrile butadiene rubber having carboxyl groups at both ends>

The component (c) constituting the NBR copolymerized polyamide imide resin (A2) of the present invention is not particularly limited as long as it is NBR having a carboxyl group at both ends (hereinafter, also simply referred to as component (c)). The component (c) is copolymerized as a flexible component that imparts adhesiveness and the like to the NBR copolymerized polyamide imide resin (A2).

The weight average molecular weight of the component (c) is preferably 500 to 5000, more preferably 1000 to 4500, and still more preferably 1500 to 4000. When the molecular weight is too low, the adhesiveness and flexibility may decrease, and when the molecular weight is too high, copolymerization becomes difficult due to a decrease in reactivity.

The proportion of the acrylonitrile moiety in the component (c) is preferably 10 to 50% by mass, more preferably 15 to 45% by mass, and still more preferably 20 to 40% by mass. If there are too few acrylonitrile sites, copolymerization becomes difficult due to a decrease in compatibility, and if too many, insulation reliability may decrease.

The copolymerization amount of the component (c) in the NBR copolymerized polyamide imide resin (A2) is required to be 1 to 5 mol%, preferably 2 to 4.8 mol%, more preferably 3 It is ∼4.6 mol%. When the copolymerization amount of the component (c) is too small, the adhesiveness and flexibility may decrease, and when too large, the insulation reliability may decrease.

In addition, the mass ratio of the component (c) in the adhesive composition is preferably 5 to 13 mass%, more preferably 6 to 12 mass% with respect to the adhesive solid component. When the mass ratio of the component (c) is too small, the adhesiveness and flexibility may decrease, and when too large, the insulation reliability may decrease.

As a commercial item of the component (c), the CTBN series of Hypro (trade name) of CVC Thermoset Specialties company etc. are mentioned, for example.

<Other acid components>

In the polyamide imide resin (A1) and NBR copolymerized polyamide imide resin (A2) of the present invention, aliphatic, alicyclic, or aromatic polycarboxylic acids are further added as needed within a range that does not impair the desired performance. It does not matter if it is copolymerized. Aliphatic dicarboxylic acids include, for example, succinic acid, glutamic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decanedioic acid, dodecanedioic acid, eicosandioic acid, 2-methylsuccinic acid, 2-methyladip Acid, 3-methyladipic acid, 3-methylpentanedicarboxylic acid, 2-methyloctanedicarboxylic acid, 3,8-dimethyldecanedicarboxylic acid, 3,7-dimethyldecanedicarboxylic acid, 9 ,12-dimethyleichoic acid diacid, fumaric acid, maleic acid, dimer acid, hydrogenated dimer acid, etc. are mentioned. As an alicyclic dicarboxylic acid, for example, 1,4-cyclohexanedicarboxylic acid, 1,3 -Cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 4,4'-dicyclohexyldicarboxylic acid, and the like, and examples of the aromatic dicarboxylic acid include isophthalic acid and terephthalic acid. , Orthophthalic acid, naphthalenedicarboxylic acid, oxydibenzoic acid, stilbenedicarboxylic acid, and the like. These dicarboxylic acids may be used alone or in combination of two or more. In consideration of heat resistance, adhesion, solubility, cost, and the like, sebacic acid, 1,4-cyclohexanedicarboxylic acid, dimer acid, or isophthalic acid is preferable.

Further, in addition to the component (c), if necessary, another flexible component may be copolymerized within a range that does not impair the target performance. For example, aliphatic/aromatic polyester diols (manufactured by Toyobo Co., Ltd., brand name VYLON (registered trademark) 200), aliphatic/aromatic polycarbonate diols (manufactured by Daicel Chemical Industries, Ltd., brand name PLACCEL (registered trademark)- CD220, Kuraray Co., Ltd., brand name C-2015N, etc.), polycaprolactone diols (Daisel Chemical Industries Co., Ltd., brand name PLACCEL (registered trademark)-220, etc.), carboxy-modified acrylonitrile butadiene rubbers ( CVC Thermoset Specialties, brand name HyproCTBN1300×13, etc.), polydimethylsiloxane diol, polymethylphenylsiloxane diol, and polysiloxane derivatives such as carboxy-modified polydimethylsiloxanes.

Polyamide-imide resin (A1) and NBR copolymerized polyamide-imide resin (A2) are prepared by using a polycarboxylic acid component having an acid anhydride group (component (a)) and an acid component having carboxyl groups at both ends. ((c) component) and an isocyanate component (component (b)) to prepare a method (isocyanate method), or a polycarboxylic acid component having an acid anhydride group (component (a)), an acid component having a carboxyl group at both ends ( There are known methods such as a method of reacting component (c) with an amine component (component (b)) to obtain an amic acid and then cyclizing (direct method). Industrially, the isocyanate method is advantageous.

In the case of the isocyanate method, the blending amount of the component (a), the component (b) and the component (c) is the ratio of the total number of acid anhydride groups + number of carboxyl groups to the number of isocyanate groups, and the number of isocyanate groups / (number of acid anhydride groups + number of carboxyl groups) = It is desirable to make it 0.8 to 1.2. When the ratio is less than 0.8, it becomes difficult to increase the molecular weight of the polyamide imide resin (A1) and NBR copolymerized polyamide imide (A2), and the coating film may become brittle. In addition, when it is higher than 1.2, the viscosity of the polyamide imide resin (A1) and NBR copolymerized polyamide imide (A2) becomes high, and the leveling property may deteriorate when the adhesive solution is applied.

The polymerization reaction of the polyamide imide resin (A1) and the NBR copolymerized polyamide imide resin (A2) used in the present invention is performed in the presence of one or more organic solvents, for example, in the isocyanate method, free-generated carbon dioxide gas is removed from the reaction system. It is preferable to carry out by heating and condensing while removing.

As the polymerization solvent, as long as the reactivity with isocyanate is low, it can be used, and for example, a solvent that does not contain a basic compound such as an amine is preferable. Examples of such solvents include toluene, xylene, ethylbenzene, nitrobenzene, cyclohexane, isophorone, diethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, dipropylene glycol Methyl ether acetate, diethylene glycol ethyl ether acetate, methyl methoxypropionate, ethyl methoxypropionate, methyl ethoxypropionate, ethyl ethoxypropionate, ethyl acetate, n-butyl acetate, isoamyl acetate, ethyl lactate, acetone, methyl Ethyl ketone, cyclohexanone, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone, γ-butyrolactone, dimethyl sulfoxide, chloroform and chloride Methylene, etc. are mentioned.

The polymerization solvent is preferably N,N-dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone, and γ-butyrolactone from the viewpoint of volatility upon drying, polymer polymerization, and solubility. More preferably, they are N,N-dimethylacetamide and γ-butyrolactone.

When N-methylpyrrolidone, N-ethylpyrrolidone, etc. are used in combination, it is included in the adhesive from the viewpoint of solvent drying property because of its high boiling point, and from the viewpoint of preventing splashing during coating due to high surface tension. It is preferable to set the mass ratio of these high boiling point solvents to 20 mass% or less with respect to the total amount of solvents.

The amount of the solvent to be used is preferably 0.8 to 5.0 times (mass ratio), more preferably 0.9 to 2.0 times, that of the resulting polyamide imide resin (A1) and NBR copolymerized polyamide imide resin (A2). When the amount is less than the above range, the viscosity at the time of synthesis is too high, and synthesis tends to be difficult due to inability to stir, and when it exceeds the above range, the reaction rate tends to decrease.

In the case of the isocyanate method, the reaction temperature is preferably 60 to 200°C, more preferably 100 to 180°C. If the reaction temperature is less than the above range, the reaction time becomes longer, and if it exceeds the above range, decomposition of the monomer component may occur during the reaction. In addition, a three-dimensional reaction occurs and gelation is likely to occur. The reaction temperature may be performed in multiple stages. The reaction time can be appropriately selected depending on the scale of the batch, the reaction conditions employed, and particularly the reaction concentration.

In the case of the isocyanate method, triethylamine, lutidine, picoline, undecene, triethylenediamine (1,4-diazabicyclo[2,2,2]octane), DBU(1,8- Amines such as diazabicyclo[5,4,0]-7-undecene), alkali metals such as lithium methylate, sodium methylate, sodium ethylate, potassium butoxide, potassium fluoride and sodium fluoride, alkaline earth metal compounds, or It may be carried out in the presence of a catalyst such as a metal such as titanium, cobalt, tin, zinc, or aluminum, or a semimetal compound.

<Production of polyamide imide resin (A1)>

The polyamide imide resin (A1) can be produced by a conventionally known method, and can be obtained, for example, by condensation reaction (polyimide) of component (a) and component (b). Hereinafter, although the manufacturing method of the polyamide imide resin (A1) of this invention is illustrated, this invention is not limited by this.

After adding and dissolving (a) component, (b) component, polymerization catalyst, and polymerization solvent to the reaction vessel, reacting at 80 to 190°C, preferably 100 to 160°C for 5 hours or more while stirring under a nitrogen stream, polymerization By diluting with a solvent to an appropriate solvent viscosity and cooling, the target polyamide imide resin (A1) can be obtained.

The polyamide imide resin (A1) of the present invention preferably has a molecular weight equivalent to a logarithmic viscosity of 0.2 to 0.4 dl/g at 30°C, more preferably a logarithmic viscosity of 0.3 to 0.35 dl/g. It has a molecular weight. When the logarithmic viscosity is less than the above range, the B-stage adhesive film may become brittle. On the other hand, if it exceeds the above range, there is a possibility that the acid value which becomes the crosslinking point with the epoxy resin (B) may decrease, or the compatibility with the NBR copolymerized polyamide imide resin (A2) may decrease.

<Preparation of NBR copolymerized polyamide imide resin (A2)>

The NBR copolymerized polyamide imide resin (A2) can be prepared by a conventionally known method, and can be obtained by, for example, condensation reaction (polyimide) of component (a), component (b), and component (c). . Hereinafter, although the manufacturing method of the NBR copolymerized polyamide imide resin (A2) of this invention is illustrated, this invention is not limited by this.

After dissolving by adding and dissolving (a) component, (b) component, (c) component, polymerization catalyst, and polymerization solvent to the reaction vessel, the mixture is stirred at 80 to 190°C, preferably 100 to 160°C for 5 hours or longer. After reacting, the target NBR copolymerized polyamide imide resin (A2) can be obtained by diluting with a polymerization solvent to an appropriate solvent viscosity and cooling.

The NBR copolymerized polyamide imide resin (A2) of the present invention preferably has a molecular weight corresponding to a logarithmic viscosity of 0.3 to 1.5 dl/g at 30°C, and more preferably, a logarithmic of 0.4 to 1.0 dl/g. It has a molecular weight corresponding to the viscosity. When the logarithmic viscosity is less than the above range, the B-stage adhesive film may become brittle. On the other hand, if it exceeds the above range, it becomes difficult to dissolve in a solvent, and it is easy to insolubilize during polymerization. In addition, the viscosity of the varnish may increase and handling may become difficult.

The glass transition temperature of the NBR copolymerized polyamide imide resin (A2) of the present invention is preferably 50°C or higher, and more preferably 100°C or higher. If it is less than 50 degreeC, there exists a possibility that the humidification solder heat resistance may fall. The upper limit is preferably 160° C. or less because it is necessary to impart adhesiveness under general press lamination temperature conditions.

<Epoxy resin (B) component>

The epoxy resin (B) of the present invention is not particularly limited as long as it is an epoxy resin having two or more epoxy groups per molecule. Although it does not specifically limit as an epoxy resin (B), For example, it may be modified with silicone, urethane, polyimide, polyamide, etc., and may contain sulfur atom, nitrogen atom, etc. in a molecular skeleton. For example, glycidyl ether epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type, or hydrogenated ones thereof, phenol novolak type epoxy resin, cresol novolak type epoxy resin, hexa And glycidyl ester-based epoxy resins such as hydrophthalate glycidyl ester and dimer acid glycidyl ester, and linear aliphatic epoxy resins such as epoxidized polybutadiene and epoxidized soybean oil. These commercially available products include, for example, bisphenol A type epoxy resins such as jER828, 1001 manufactured by Mitsubishi Chemical Co., Ltd., and hydrogenated bisphenol A type epoxy resins manufactured by Shinnittetsu Sumikin Chemicals, such as ST-2004 and 2007. Resin, EXA-9726 manufactured by DIC Corporation, bisphenol F type epoxy resin manufactured by Shinnittetsu Sumikin Chemical Co., Ltd. YDF-170, 2004, etc., brand names jER152, 154 manufactured by Mitsubishi Chemical Corporation, Dow Chemical Brand name DEN-438 manufactured by DIC Corporation, phenol novolak type epoxy resin such as HP7200, HP7200H manufactured by DIC Corporation, brand name YDCN-700 series manufactured by Shinnittetsu Sumikin Chemical Co., Ltd., manufactured by Nippon Kayaku Corporation Cresol novolac type epoxy resins such as EOCN-125S, 103S, 104S, etc., and flexible epoxy resins such as YD-171 manufactured by Shinnittetsu Sumikin Chemical Co., Ltd., and brand names Epon1031S manufactured by Mitsubishi Chemical Corporation, Chiba Brand name Araldite 0163 manufactured by Specialty Chemicals Co., Ltd., brand name DENACOL EX-611, EX-614, EX-622, EX-512, EX-521, EX-421, manufactured by Nagase Chemtech Co., Ltd. Multifunctional epoxy resins such as EX-411 and EX-321, brand name Epicoat 604 manufactured by Mitsubishi Chemical Co., Ltd., brand name YH-434 manufactured by Shinnittetsu Sumikin Chemical Co., Ltd., manufactured by Chiba Specialty Chemical Co., Ltd. Araldite PT810 and other heterocyclic-containing epoxy resins, Daicel Chemical Industry Co., Ltd. trade names Seroxide 2021, EHPE3150, UCC made ERL4234 and other alicyclic epoxy resins, DIC Co., Ltd. product trade name Epi Bisphenol S-type epoxy resin such as clone EXA-1514, triglycidyl isocyanurate such as TEPIC manufactured by Nissan Chemical Industries, Ltd., bixylenol-type epoxy resin such as brand name YX-4000 manufactured by Mitsubishi Chemical Corporation, Bisphenol-type epoxy resins such as the brand name YL-6056 manufactured by Mitsubishi Chemical Co., Ltd. are mentioned, and these are independent You may use it, and you may use it in combination of several.

In addition, the epoxy resin (B) generally contains chlorine as an impurity in its manufacturing process. However, it is required to reduce the amount of halogen from the viewpoint of reducing the environmental load, and it is known that the insulating property decreases when there is a large amount of chlorine, particularly hydrolyzable chlorine. Therefore, the total amount of chlorine contained in the epoxy resin (B) is preferably 2000 ppm or less, more preferably 1500 ppm or less, and still more preferably 1000 ppm or less. In addition, it is preferable that the total amount of chlorine in the nonvolatile component of the adhesive is 500 ppm or less.

Among these epoxy resins, (B1) is preferably a liquid epoxy resin at room temperature from the viewpoint of imparting temporary adhesiveness to the B stage adhesive film, and more preferably an epoxy resin that is liquid at room temperature and has two or more epoxy groups per molecule. desirable. Examples of the epoxy resin (B1) include a bisphenol A type epoxy resin and a bisphenol F type epoxy resin. Further, for the purpose of increasing the crosslinking density of the coating film after heat curing, a solid epoxy resin (B2) at room temperature can be used. (B2) is a solid at room temperature and is preferably an epoxy resin having two or more epoxy groups per molecule, and more preferably a solid at room temperature and an epoxy resin having more than two epoxy groups per molecule. Examples of the polyfunctional epoxy (B2) include phenol novolak type epoxy resins and o-cresol novolak type epoxy resins having a large number of functional groups. It is preferable that any one of (B1) and (B2) has two or more epoxy groups per molecule, and it is more preferable that both (B1) and (B2) have two or more epoxy groups per molecule.

Increasing the crosslinking density of the coating film after heat curing is to suppress the water absorption of the coating film under moisture absorption conditions (temperature 40°C, humidity 80% RH, 2 days) in the humidification solder heat resistance evaluation, and heat curing at 170°C for 3 hr. , It can be performed by making the molecular weight between crosslinking points calculated|required by the following formula into 2000 or less, and the humidification solder heat resistance can be improved by this. The lower limit of the molecular weight between crosslinking points is not particularly limited, but is generally about 300.

Molecular weight between crosslinking points (Mc) = 3ρRT×1000000/E'

However, R = 8.31 [Jmol ^-1 K ^-1 ], E'and T are determined by dynamic viscoelasticity measurement, and ρ is determined by specific gravity measurement.

The upper limit of the epoxy groups of the polyfunctional epoxy (B2) having more than two epoxy groups per molecule is not particularly limited, but considering that the number of commercially available products is generally 12 or less, it is 12.

As the epoxy resin (B), in the ratio of the combination of a liquid epoxy resin (B1) at room temperature in the composition and a polyfunctional epoxy (B2) having more than two epoxy groups per molecule, from the viewpoint of provision of temporary adhesiveness, It is preferable to set B1/(B1+B2) to 0.6 or more by mass ratio, and 0.65 or more is more preferable. The upper limit of the mass ratio is not particularly limited and is 1.0.

The epoxy resin (B) used in the present invention may further contain an epoxy compound having only one epoxy group per molecule as a diluent.

In the adhesive composition of the present invention, in order to impart temporary adhesion to the B-stage adhesive film and to increase the crosslinking density of the coating film after heat curing to improve the humidification solder heat resistance and insulation reliability, the mass ratio of (A1+A2)/B is It is important. (A1+A2)/B is preferably 0.9 or more and 3.6 or less, and more preferably 1.0 or more and 3.5 or less. If the mass ratio is less than the above range, the crosslinking density of the coating film after heat curing becomes low, and the humidification solder heat resistance and insulation reliability become insufficient, and if it exceeds the above range, the B-stage adhesive film temporary adhesiveness is insufficient, which is not preferable.

In addition, when a phosphorus-based flame retardant having a phenolic hydroxyl group is used in combination, the compound having a phenolic hydroxyl group is an epoxy resin (B) similar to the polyamide imide resin (A1) or the NBR copolymerized polyamide imide resin (A2). It acts as a heat curing agent. Accordingly, it is possible to increase the crosslinking density of the coating film after heat curing, thereby improving the humidification solder heat resistance and insulation reliability. When the phosphorus-based flame retardant having a phenolic hydroxyl group is used in combination, the amount of the epoxy resin (B) used is the total amount of the epoxy group in the epoxy resin (B), which is a thermosetting resin, and the acid value of the thermosetting agents (A1) and (A2) reacting with the epoxy group. It is necessary to determine in consideration of the balance between the total number of hydroxyl groups in the compound having a phenolic hydroxyl group. Therefore, it is preferable that the numerical value calculated by the following formula is 1.5-7.0, and it is more preferable that it is 2.0-6.0. When this value is less than the above range, there is a risk that a part of the thermosetting agent may remain unreacted even after thermal curing due to insufficient epoxy resin (B), while when it exceeds the above range, an excess amount of epoxy resin (B ) May remain unreacted even after thermal curing. When the crosslinking density of the coating film after heat curing is lowered, the humidification solder heat resistance and insulation reliability may decrease.

Compounding ratio of epoxy resin solid content (parts by mass) to adhesive solid content (parts by mass) × epoxy equivalent [eq/t]/(polyamide imide resin (A1) solid content (parts by mass) to adhesive solid content (parts by mass)) Blending ratio × acid value of polyamide imide resin (A1) [eq/t] + NBR copolymerized polyamide imide resin (A2) solid content (parts by mass) to adhesive solid content (parts by mass) × NBR copolymerized polyamide The acid value of the imide resin (A2) [eq/t] + the compounding ratio of the solid content of the compound having a phenolic hydroxyl group to the solid content of the adhesive (parts by mass) × phenolic hydroxyl value [eq/t]}

<Phosphorus flame retardant (C) component>

It is preferable that the adhesive composition of the present invention further contains a phosphorus-based flame retardant (C). By blending the phosphorus-based flame retardant (C), the flame retardancy of the adhesive can be improved. The phosphorus-based flame retardant (C) is not particularly limited as long as it contains a person in the structure, but a phosphazene or a phosphinic acid derivative is preferable from the viewpoint of hydrolysis resistance, heat resistance, bleed-out and the like. These may be used alone or in combination of two or more.

The phosphazene compound is represented by the following general formula [I] or [II] (in the formula, X may be the same or different, and represents hydrogen, a hydroxyl group, an amino group, an alkyl group, an aryl group, an organic group, and organic Examples of the group include an alcohol group, a phenoxy group, an allyl group, a cyanophenoxy group, and a hydroxyphenoxy group, and n is an integer of 3 to 25).

Commercially available products of these phosphazene compounds include, for example, cyclic phenoxy phosphazene (manufactured by Otsuka Chemical Co., Ltd., trade names: SPB-100, SPE-100), cyclic cyanophenoxy phosphazene (Fushimi Co., Ltd.) Pharmaceutical manufacturing, brand name: FP-300), cyclic hydroxyphenoxy phosphazene (made by Otsuka Chemical Co., Ltd., brand name: SPH-100), etc. are mentioned. These are the main components of n = 3, and have three functional groups reacting with an epoxy group. In addition, phosphazene, which does not have a reactive functional group with the epoxy resin (B), bleeds out over time and elutes phosphorus in the glass under the influence of hydrolysis under severe conditions of use, thereby reducing electrical insulation. There are cases. Therefore, reactive phosphazene having a functional group reacting with the epoxy resin (B) is preferred. Specifically, cyclic hydroxyphenoxy phosphazene and the like having a phenolic hydroxyl group can be mentioned.

As the phosphinic acid derivative, a phenanthrene-type phosphinic acid derivative is preferable. For example, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (manufactured by Sanko Co., Ltd., brand name: HCA) ), 10-benzyl-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide (manufactured by Sanco Co., Ltd., brand name: BCA), 10-(2,5-dihydroxyphenyl)-10 -H-9-oxa-10-phosphaphenanthrene-10-oxide (made by Sanko Co., Ltd., brand name HCA-HQ), etc. are mentioned. Among the above-described phosphinic acid derivatives, HCA has reactivity with the epoxy resin (B), but bleed-out occurs and high temperature and high humidity resistance may be inferior. Therefore, it is necessary to appropriately select the blending amount in consideration of performance. In addition to the above phosphorus compounds, other phosphorus compounds may be used alone or in combination of two or more, as long as the flame retardancy, solder heat resistance, and bleed-out are not impaired.

As the phosphorus-based flame retardant (C), it is preferable to use (i) a phosphorus-based flame retardant having no functional group reacting with an epoxy group, and (ii) a phosphorus-based flame retardant having two or more, particularly three functional groups reacting with the epoxy group. The ratio of the phosphorus-based flame retardant of (i) and (ii) is preferably 1:9 to 9:1, and more preferably 2:8 to 8:2 in terms of mass ratio. When the phosphorus-based flame retardant of (i) is large, the insulation reliability may be deteriorated, and when the phosphorus-based flame-retardant of (ii) is large, the adhesiveness may decrease.

(i) A phosphorus-based flame retardant that does not have a functional group reacting with an epoxy group has a role of imparting flexibility to the adhesive after heat curing because it is not introduced into the crosslinked structure during thermal curing. For example, the aforementioned cyclic phenoxy phosphazene (manufactured by Otsuka Chemical Co., Ltd., trade names: SPB-100, SPE-100), cyclic cyanophenoxy phosphazene (manufactured by Fushimi Pharmaceutical Co., Ltd.), brand name: FP -300), 10-benzyl-10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide (manufactured by Sanko Co., Ltd., brand name: BCA) or phosphoric acid ester system (manufactured by Daihachi Chemical, brand name: PX-200) and so on. (ii) A phosphorus-based flame retardant having two or more functional groups reacting with an epoxy group has a role of suppressing bleed-out and not reducing heat resistance by being introduced into a crosslinked structure during thermal curing. For example, the aforementioned cyclic hydroxyphenoxy phosphazene (manufactured by Otsuka Chemical Co., Ltd., trade name: SPH-100), 10-(2,5-dihydroxyphenyl)-10-H-9-oxa-10- These include phosphaphenanthrene-10-oxide (manufactured by Sanko Co., Ltd., brand name HCA-HQ). Here, in the case of having one functional group reacting with the epoxy, since it becomes the terminal of the crosslinked structure and cuts the network, there is a possibility that the effect of not lowering the heat resistance of (ii) becomes insufficient.

The amount of the phosphorus-based flame retardant (C) used in the present invention is preferably used so that the phosphorus content of the adhesive solid content is 1.1 to 5.0, and more preferably 1.2 to 4.0. When the phosphorus content of the adhesive solid content is less than the above range, the flame retardancy may be lowered, and when it exceeds the above range, the B-stage adhesive film embrittlement resistance may decrease.

<Other ingredients>

In the adhesive composition of the present invention, in addition to the polyamide imide resin (A1), NBR copolymerized polyamide imide resin (A2), epoxy resin (B) and phosphorus flame retardant (C), properties such as adhesion, chemical resistance, and heat resistance In order to further improve this, a curing accelerator (polymerization catalyst) can be added. As the curing accelerator used in the present invention, any one capable of accelerating the curing reaction of the polyamide imide resin (A) and the epoxy resin (B) is not particularly limited.

As a specific example of such a curing accelerator, for example, manufactured by Shikoku Chemical Industries, Ltd., 2MZ, 2E4MZ, C11Z, C17Z, 2PZ, 1B2MZ, 2MZ-CN, 2E4MZ-CN, C11Z-CN, 2PZ-CN, 2PHZ-CN , 2MZ-CNS, 2E4MZ-CNS, 2PZ-CNS, 2MZ-AZINE, 2E4MZ-AZINE, C11Z-AZINE, 2MA-OK, 2P4MHZ, 2PHZ, 2P4BHZ and other imidazole derivatives, acetoguanamine, benzoguanamine, etc. Namines, diaminodiphenylmethane, m-phenylenediamine, m-xylenediamine, diaminodiphenylsulfone, dicyandiamide, urea, urea derivatives, melamine, polyamines such as polybasic hydrazide, and organic acid salts thereof And/or an epoxy adduct, an amine complex of boron trifluoride, ethyldiamino-S-triazine, 2,4-diamino-S-triazine, 2,4-diamino-6-xylyl-S-tri Triazine derivatives such as azine, trimethylamine, triethanolamine, N,N-dimethyloctylamine, N-benzyldimethylamine, pyridine, N-methylmorpholine, hexa(N-methyl)melamine, 2,4,6- Tris(dimethylaminophenol), tetramethylguanidine, DBU(1,8-diazabicyclo[5,4,0]-7-undecene), DBN(1,5-diazabicyclo[4,3,0] -5-nonene), and other organic acid salts and/or tetraphenylboroate, polyvinylphenol, polyvinylphenol bromide, tributylphosphine, triphenylphosphine, tris-2-cyanoethyl Organic phosphines such as phosphine, quaternary phosphonium such as tri-n-butyl (2,5-dihydroxyphenyl) phosphonium bromide, hexadecyltributylphosphonium chloride, and tetraphenylphosphonium tetraphenylboroate Salts, quaternary ammonium salts such as benzyltrimethylammonium chloride and phenyltributylammonium chloride, the polycarboxylic anhydride, diphenyliodonium tetrafluoroboroate, triphenylsulfonium hexafluoroantimonate, 2,4 ,6-triphenylthiopyryllium hexafluorophosphate, Irgacure 261 (manufactured by Chiba Specialty Chemical Co., Ltd.), Optmer SP-170 (manufactured by ADEKA Co., Ltd.), and other photocationic polymerization catalysts, styrene- Anhydrous An equimolar reaction product of a leic acid resin, an equimolar reaction product of phenyl isocyanate and dimethylamine, and an equimolar reaction product of an organic polyisocyanate such as tolylene diisocyanate and isophorone diisocyanate and dimethylamine. You may use these individually or in combination of 2 or more types. Preferably, it is a curing accelerator having latent curing properties, and examples thereof include organic acid salts of DBU and DBN and/or tetraphenylboroate, photocationic polymerization catalysts, and the like.

The amount of the curing accelerator used is preferably 0 to 20 parts by mass when the total of the polyamide imide resin (A1) + NBR copolymerized polyamide imide (A2) is 100 parts by mass. When it exceeds 20 parts by mass, storage stability and humidification solder heat resistance of the resin composition may decrease.

To the adhesive composition of the present invention, a compound having a phenolic hydroxyl group can be added to the adhesive composition of the present invention for the purpose of increasing the crosslinking density of the coating film after heat curing and improving insulation reliability and humidification solder heat resistance within the range not impairing the effects of the present invention have. The compound having a phenolic hydroxyl group is not particularly limited as long as it contains a phenolic hydroxyl group in the structure. From the viewpoint of solvent solubility and compatibility with polyamide-imide resin, a compound having a high phenolic hydroxyl group concentration is preferred.

Commercially available products of these compounds include, for example, Asahi Organic Materials Co., Ltd. EP4020G, EP4050G, EP4080G, EPR5010G, EPR5030G, EP6050G, Yasuhara Chemical Co., Ltd. YS Polystar K125, K140, G125, G150, Maywa Chemical Co., Ltd. ) Manufacturing MEHC-7800 grade, MEHC-7851 grade, MEHC-7841 grade, MEH-8000 grade, MEH-7000, MEH-7600 series, MEH-7500 series, DL-series, H-4, HF-1M, HF- 3M, HF-4M, XMEH-001-01, XMEH-002-01, XMEH-003-01, Sumikanol 610 manufactured by Taoka Chemical Industries, Ltd., Tamanol 1010R manufactured by Arakawa Chemical Industries, Tamanol 100S, Tamanol 510, Tamanol 7509, Tamanol 7705, Showa Denko Shounol CKM-1634, Shounol CKM-1636, Shounol CKM-1737, Shounol CKM-1282, Shounol CKM-904, Shounol CKM-907, Shounol CKM -908, Shounol CKM-983, Shounol CKM-2400, Shounol CKM-941, Shounol CKM-2103, Shounol CKM-2432, Shounol CKM-5254, BKM-2620, BRP-5904, RM-0909 , BLS-2030, BLS-3574, BLS-3122, BLS-362, BLS-356, BLS-3135, CLS-3940, CLS-3950, BRS-356, BRS-621, BLL-3085, BRL-113, BRL -114, BRL-117, BRL-134, BRL-274, BRL-2584, BRL-112 A, BRL-120 Z, CKS-3898, Schenectadi Chemical Co., Ltd. SP-460B, SP-103H, HRJ-1367 , Gunei Chemical Industry Co., Ltd. Regitop PL2211, Sumitomo Bakelite Co., Ltd. PR-HF-3, PR-53194, PR-53195, Hood Co., Ltd. Nicanol HP-150, Nicanol HP-120, Nicanol HP-100, Nicanol HP-210, manufactured by DIC Pryophene 5010, Pryophene 503, TD-447, etc. are mentioned.

In addition, examples of the compounds that generate phenolic hydroxyl groups by self-crosslinking during thermal curing include Fa-type benzoxazine, Pd-type benzoxazine, and BF-BXZ and BS-BXZ, manufactured by Shikoku Chemical Industries, Ltd. have.

The compounding amount of the compound having a phenolic hydroxyl group is preferably 3 to 20 parts by mass when the total of the polyamide imide resin (A1) + NBR copolymerized polyamide imide (A2) is 100 parts by mass. When it is less than 3 parts by mass, the effect of improving the crosslinking density is difficult to be obtained, and when it exceeds 20 parts by mass, there is a fear that the B-stage sheet may become brittle.

To the adhesive composition of the present invention, a high heat-resistant resin can be added for the purpose of suppressing leakage during thermal compression within a range not impairing the effects of the present invention. As a high heat-resistant resin, it is preferable that it is a resin with a glass transition temperature of 160 degreeC or more like polyamide imide resin (A1). Although it does not specifically limit specifically, Polyimide resin, polyetherimide resin, polyether ether ketone resin, etc. are mentioned. In addition, it is preferable to dissolve the high heat-resistant resin in a solvent. As for satisfying these conditions, when the constituent units derived from all acid components are set to 100 mol%, a resin in which an anhydride of the polycarboxylic acid having an aromatic ring is 90 mol% or more is preferable. The blending amount of these high heat-resistant resins is preferably 5 to 60 parts by mass, more preferably 6 to 50 parts by mass, when 100 parts by mass of the NBR copolymerized polyamide imide (A2) is used. When the blending amount is too small, it is difficult to obtain an effect of suppressing outflow, and when too large, the temporary adhesiveness and adhesiveness of the B-stage adhesive sheet may be deteriorated.

In addition to the above-described epoxy resin (B), glycidylamine can be added to the adhesive composition of the present invention for the purpose of reducing the outflow of the adhesive during lamination within a range not impairing the effects of the present invention. The amount of glycidylamine to be added is preferably 0.01 to 5% by mass relative to the total mass of the polyamide imide resin (A1), the NBR copolymerized polyamide imide (A2), and the epoxy resin (B) in the adhesive, 0.05-2 mass% is more preferable. When the addition amount of glycidylamine is too large, the fluidity of the adhesive at the time of lamination is too small, and the embedding property of the circuit may be lowered, and when the addition amount is too small, there is a possibility that a sufficient spill suppression effect cannot be obtained. Examples of the glycidylamine include the brand names TETRAD-X and TETRAD-C manufactured by Mitsubishi Gas Chemical Co., Ltd., the brand name GAN manufactured by Nippon Kayaku Co., Ltd., and the brand name ELM-120 manufactured by Sumitomo Chemical Co., Ltd. There are, and these may be used individually or may be used in combination of multiple.

To the adhesive composition of the present invention, a silane coupling agent may be added for the purpose of improving adhesion, and a conventionally known silane coupling agent is not particularly limited. Specific examples thereof include aminosilane, mercaptosilane, vinylsilane, epoxysilane, methacrylic silane, isocyanate silane, ketimine silane or a mixture or reactant thereof, or a compound obtained by reaction of these and polyisocyanates. I can. Examples of such silane coupling agents include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylethyldiethoxysilane, and bistrimethoxysilyl. Propylamine, bistriethoxysilylpropylamine, bismethoxydimethoxysilylpropylamine, bisethoxydiethoxysilylpropylamine, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2 -(Aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylethyldiethoxysilane Aminosilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropylmethyldiethoxysilane, γ-mercaptopropyl Mercaptosilane such as ethyl diethoxysilane, vinyl trimethoxysilane, vinyl triethoxysilane, vinyl silane such as toris-(2-methoxyethoxy) vinylsilane, γ-glycidoxypropyltrimethoxysilane, γ -Glycidoxypropyldimethylethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethylmethyldimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β -(3,4-epoxycyclohexyl) Epoxysilane such as ethyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldie Methacrylsilanes such as oxysilane and 3-methacryloxypropyltriethoxysilane, isocyanate silanes such as isocyanate propyltriethoxysilane, isocyanate propyltrimethoxysilane, etc. Ketimine silanes such as oxysilane may be mentioned, and these may be used alone or in combination of two or more. Among these silane coupling agents, since the epoxy silane has a reactive epoxy group, it can react with the polyamide imide resin, and is preferable from the viewpoint of improving heat resistance and moist heat resistance. The blending amount of the silane coupling agent is preferably 0 to 10% by mass, more preferably 0 to 5% by mass when the total nonvolatile content of the adhesive composition is 100% by mass. When the blending amount exceeds the above range, the humidification solder heat resistance may decrease.

To the adhesive composition of the present invention, an organic/inorganic filler can be added for the purpose of improving the solder heat resistance within a range that does not impair the effects of the present invention. As an inorganic filler, for example, silica (SiO ₂ , brand name aerogel manufactured by Aerosil Co., Ltd. in Japan), alumina (Al ₂ O ₃ ), titania (TiO ₂ ), tantalum oxide (Ta ₂ O ₅₎ ), zirconia (ZrO ₂ ), silicon nitride (Si ₃ N ₄ ), barium titanate (BaO TiO ₂ ), barium carbonate (BaCO ₃ ), lead titanate (PbO TiO ₂ ), lead zirconate titanate (PZT), zircon titanate Scattering lead (PLZT), gallium oxide (Ga ₂ O ₃ ), spinel (MgO·Al ₂ O ₃ ), mullite (3Al ₂ O ₃ ·2SiO ₂ ), cordierite (2MgO·2Al ₂ O ₃ ·5SiO ₂ ), talc (3MgO·4SiO ₂ ·H ₂ O), aluminum titanate (TiO ₂ -Al ₂ O ₃ ), yttria-containing zirconia (Y ₂ O ₃ -ZrO ₂ ), barium silicate (BaO·8SiO ₂ ), nitriding Boron (BN), calcium carbonate (CaCO ₃ ), calcium sulfate (CaSO ₄ ), zinc oxide (ZnO), magnesium titanate (MgO TiO ₂ ), barium sulfate (BaSO ₄ ), organic bentonite, carbon (C), organic Smectite (trade name Lucentite (registered trademark) STN, Lucentite SPN, Lucentite SAN, Lucentite SEN manufactured by Corp. Chemical Co., Ltd.) can be used, and these may be used alone or in combination of two or more. .

As the inorganic filler used in the present invention, the average particle diameter is preferably 50 μm or less, and the maximum particle diameter is 100 μm or less, more preferably 20 μm or less, and the average particle diameter 10 μm or less is the most. desirable. The average particle diameter (median diameter) referred to herein is a value obtained on a volume basis using a laser diffraction/scattering particle size distribution measuring device. When the average particle diameter exceeds 50 μm, there is a possibility that the B-stage adhesive film may become brittle, and appearance defects may occur.

Examples of the organic filler used in the present invention include polyimide resin particles, benzoguanamine resin particles, and epoxy resin particles.

To the adhesive composition of the present invention, a silicone-based, fluorine-based, polymer-based antifoaming agent or a leveling agent may be added for the purpose of improving the leveling property and defoaming property at the time of application within a range that does not impair the effects of the present invention.

The blending amount of these other components is preferably less than 25 mass% in total when the nonvolatile content of the adhesive composition is 100 mass%. That is, by setting the blending amount of the main component A1+A2+B+C to 75% by mass or more, desired adhesive properties can be expressed.

<Adhesive composition (adhesive)>

The adhesive composition (adhesive) of the present invention contains the aforementioned polyamide imide resin (A1) component, NBR copolymerized polyamide imide (A2), and epoxy resin (B) component, and if necessary, a phosphorus-based flame retardant (C) It is a composition containing the ingredients. Further, if necessary, other blending components can be blended in the above-described ratio. Thereby, it can be used as an adhesive agent suitable for a flexible printed wiring board.

<Adhesive solution>

The adhesive solution is obtained by dissolving the adhesive composition (adhesive) of the present invention in the polymerization solvent. As for the adhesive solution, the viscosity in the B-type viscometer is preferably in the range of 3 dPa·s to 30 dPa·s at 25°C, and more preferably in the range of 4 dPa·s to 20 dPa·s. When the viscosity is less than the above range, the amount of solution flowing out during application increases, and the film thickness tends to become thinner. When the viscosity exceeds the above range, there is a tendency for the leveling property to the substrate to decrease during application.

<Adhesive film>

The adhesive solution can obtain an adhesive film by distilling off the solvent in the following manner, for example. That is, the above-described adhesive solution was applied to the release film with a film thickness of 5 to 80 μm by a method such as a screen printing method, a spray method, a roll coating method, an electrostatic coating method, and a curtain coating method, and the coating film was applied at 60 to 150°C. After drying for 3 to 10 minutes, the solvent is distilled off. Drying may be in air or in an inert atmosphere.

Further, for the purpose of adjusting the fluidity of the adhesive at the time of thermocompression bonding, heat treatment is performed after drying the solvent, and the polyamide imide resin and the epoxy resin are partially reacted in some cases. In addition, the state before thermocompression bonding is called a B stage.

As a site|part where an adhesive is used in FPC, a CL film, an adhesive film, and a three-layer copper-clad laminated board are mentioned.

In a CL film and an adhesive film, it is common to perform processing, such as winding, storage, cutting, punching, etc. in a B-stage state, and flexibility in a B-stage state is also required. On the other hand, in a three-layer copper clad laminate, it is common to perform thermocompression bonding and thermosetting immediately after formation of the B-stage state.

In addition, in all of the above applications, a B-stage adhesive film is thermocompressed with an adherend, and a thermosetting treatment is performed before use.

The CL film is composed of an insulating plastic film/adhesive layer or an insulating plastic film/adhesive layer/protective film. An insulating plastic film is a film with a thickness of 1 to 200 μm made of plastics such as polyimide, polyamide imide, polyester, polyphenyrene sulfide, polyether sulfone, polyether ether ketone, aramid, polycarbonate, and polyarylate. And a plurality of films selected from these may be laminated. The protective film is not particularly limited as long as it can be peeled off without impairing the properties of the adhesive. For example, polyethylene, polypropylene, polyolefin, polyester, polymethylpentene, polyvinyl chloride, polyvinylidene fluoride, polyphenyrene sulfide, etc. A plastic film, a film obtained by coating these with silicone or fluoride or other releasing agent, a paper laminated with them, and a paper impregnated or coated with a releasable resin may be mentioned.

The adhesive film is a structure in which a protective film is formed on at least one side of an adhesive layer made of an adhesive, and is a configuration of a protective film/adhesive layer, or a protective film/adhesive/protective film. In some cases, an insulating plastic film layer is formed in the adhesive layer. The adhesive film can be used for multilayer printed circuit boards.

The three-layer copper-clad laminate is a configuration in which copper foil is bonded to at least one surface of an insulating plastic film with an adhesive. The copper foil is not particularly limited, but a rolled copper foil or an electrolytic copper foil conventionally used for a flexible printed wiring board can be used.

The polyamide-imide resin layer of the FPC thus obtained becomes a solder resist layer, a surface protective layer, an interlayer insulating layer, or an adhesive layer of a flexible printed wiring board. As described above, the polyamide-imide resin composition of the present invention can be used as a film forming material, not only useful for overcoat inks for semiconductor devices and various electronic components, solder resist inks, and interlayer insulating films, but also as paints, coatings, adhesives, and the like. Here, the solder resist layer is a film formed on the entire surface of the circuit conductor except for the part to be soldered. When wiring electronic components to a printed wiring board, solder is prevented from adhering to unnecessary parts, and the circuit is directly exposed to air. It is used as a protective film to prevent exposure. The surface protective layer is used to mechanically and chemically protect an electronic member from a processing process or a use environment by bonding to the surface of a circuit member. The interlayer insulating layer is used in order to prevent energization between layers in which fine wiring is formed in the package substrate. The adhesive layer is mainly used when bonding a metal layer and a film layer to perform bonding processing.

Example

Examples are given below to illustrate the present invention more specifically, but the present invention is not limited thereto. The evaluation of the characteristic value in Examples was performed by the following method.

<Logarithmic viscosity>

Polyamide imide resin (A1) or NBR copolymerized polyamide imide resin (A2) was dissolved in N-methyl-2-pyrrolidone so that the polymer concentration was 0.5 g/dl. The solution viscosity and solvent viscosity of the solution were measured at 30° C. with an Uberod type viscometer and calculated by the following equation.

Logarithmic viscosity (dl/g) = [ln(V1/V2)]/V3

V1: Calculated from the time the solvent (N-methyl-2-pyrrolidone) passes through the capillary of the Uberod type viscometer

V2: Calculated from the time the polymer solution passes through the capillary of the Uberod type viscometer

V3: polymer concentration (g/dl)

<acid value>

0.2 g of polyamide imide resin (A1) or NBR copolymerized polyamide imide resin (A2) was dissolved in 20 ml of N-methylpyrrolidone and titrated with 0.1 N potassium hydroxide ethanol solution, (A) The equivalent (equivalent / 10 6 g) per 10 6 g of the component was determined.

<Adhesion>

The adhesive solution was applied to a polyimide film (Apical 12.5 NPI manufactured by Kaneka) so that the thickness after drying was 20 μm, and dried with a hot air dryer at 140° C. for 3 minutes to obtain a B-stage adhesive film. The adhesive coated surface of this B-stage adhesive film and the glossy surface of copper foil (BHY thickness 18 μm manufactured by ENEOS) were thermocompressed under reduced pressure at 160° C., 3 MPa for 30 seconds with a vacuum press laminator, and then heated and cured at 170° C. for 3 hours. . The cured laminate was peeled off at a rate of 50 mm/min in the direction of 90° in an atmosphere of 25°C using a tensile tester (autograph AG-X plus manufactured by Shimadzu) to measure the adhesive strength.

○: adhesion strength of 0.6 N/mm or more or re-breaking of polyimide film

×: adhesive strength less than 0.6 N/mm

<Insulation reliability>

A B-stage adhesive film was prepared in the same manner as in the adhesive evaluation, and heat-compressed under reduced pressure at 160°C, 3 MPa for 30 seconds on a comb-shaped pattern of L/S = 50/50 μm using a vacuum press laminating machine, and then 170°C. It cured by heating for 3 hours. In an environment at a temperature of 85°C and a humidity of 85%, a voltage of 200 V was applied for 250 hours.

○: Resistance after 250 hours is 1×10 ⁸ Ω or more, and there is no dendrite

×: Resistance value after 250 hours ^{is less than 1×10 8} Ω, with dendrites

××: Short circuit within 250 hours

<Outflow>

In the same manner as in the insulation reliability evaluation, the B-stage adhesive film was thermocompressed on a comb-shaped pattern of L/S = 50/50 μm using a vacuum press laminating machine at 160° C., 3 MPa, for 30 seconds under reduced pressure, and between the wirings from the CL end. The amount of the spilled adhesive was measured under a microscope.

○: Outflow amount less than 100 μm

×: Outflow amount 100 μm or more

<Humidification solder heat resistance>

In the same manner as in the adhesive evaluation, a heat-cured laminate was prepared, cut into 20 mm in width and length, left standing for 2 days in an environment at a temperature of 40°C and a humidity of 80% RH, and then placed the polyimide side up in a 280°C solder bath. Float for 1 minute.

○: No swelling or peeling

×: There is swelling or peeling

<Adhesive composition morphology measurement>

The adhesive solution was applied to a glossy surface of copper foil (BHY thickness 18 μm manufactured by ENEOS) so that the thickness after drying became 20 μm, followed by heating and curing at 170° C. for 3 hours. The obtained sample was embedded in an epoxy resin, and a frozen section was produced using a cryomicrotome. The prepared section was dyed in OsO4 vapor for 30 minutes and carbon-deposited. The observation was made under conditions of an acceleration voltage of 200 kV using a JEM2100 transmission electron microscope manufactured by Nippon Denshi.

○: The adhesive composition does not contain domains of 0.1 μm or more and forms a homogeneous phase.

×: The adhesive composition contains a domain of 0.1 μm or more and forms a phase-separated structure of the islands.

<Flame retardant>

A B-stage adhesive film was prepared in the same manner as in the evaluation of adhesion, and the adhesive coated surface and the polyimide film (Apical 12.5NPI manufactured by Kaneka) were thermocompressed under reduced pressure at 160°C for 30 seconds using a vacuum press laminating machine. Then, it heat-hardened at 170 degreeC for 3 hours. The sample after curing was evaluated for flame retardancy according to the UL-94 VTM standard.

○: VTM-0 equivalent

×: Does not satisfy VTM-0

<B-stage adhesive film embrittlement resistance>

The adhesive solution was applied to a PET film (E5101 thickness 50 μm manufactured by Toyobo) so that the thickness after drying was 20 μm, and dried with a hot air dryer at 140° C. for 3 minutes to obtain a B-stage adhesive film. The adhesive side was wound on the outside and bent by 180°, and 1 kg of a bell was placed on it.

○: No cracking occurs in the adhesive film

×: cracking occurs in the adhesive film

<Temporary adhesion of B-stage adhesive film>

Heat the coated surface of the B-stage adhesive film and the glossy surface of copper foil (18 μm thickness of BHY manufactured by ENEOS) of the B-stage adhesive film obtained in the same manner as the B-stage adhesive film embrittlement resistance evaluation under the conditions of 90°C, 0.3 MPa, and 0.75 m/min. Squeezed.

○: The adhesive film is completely transferred to the copper foil.

△: Part of adhesive film is transferred to copper foil, part remains on PET film, fracture

X: The adhesive film is not transferred to the copper foil at all, and remains on the PET film.

<ACF adhesion>

The adhesive solution was applied to the non-gloss surface of a rolled copper foil (BHY thickness 12 μm manufactured by ENEOS) so that the thickness after drying became 3.5 μm, and dried with a hot air dryer at 140° C. for 3 minutes to obtain a B-stage adhesive film. A copper foil/adhesive/polyimide film was formed by thermocompressing the adhesive coated surface of this B-stage adhesive film and the polyimide film (Apical 12.5NPI manufactured by Kaneka) under reduced pressure at 130°C, 2 MPa for 5 seconds with a vacuum press lamination machine. The resulting three-layer single-sided CCL was obtained. Further, a 5-layer double-sided CCL composed of copper foil/adhesive/polyimide film/adhesive/copper foil was prepared by thermocompressing a B-stage adhesive film on the polyimide surface of the obtained laminate by the same method, and 2 at 100°C. Time, followed by heat curing at 200°C for 3 hours.

Next, the obtained double-sided CCL was patterned with L/S = 0.1/0.1 mm and cut into a size of 10 x 30 mm. The patterned double-sided FPC and ACF (AC-7106 manufactured by Hitachi Chemical Co., Ltd.) were pre-attached by thermocompression bonding at 80° C., 1 MPa for 5 seconds, and the ACF side and soda glass (26×76 mm t = 1.3 mm) of the obtained FPC/ACF laminate. ) Was thermocompressed at 180° C., 2 MPa, for 15 seconds.

Regarding the obtained FPC/ACF/soda glass laminate, the FPC was peeled in a direction of 90° at a rate of 50 mm/min in an atmosphere of 25° C. using a tensile tester, and the adhesive strength was measured.

○: Adhesive strength of 0.5 N/mm or more or FPC re-breaking

×: adhesive strength less than 0.5 N/mm

<Molecular weight between cross-linking points>

It was calculated by the following formula.

Molecular weight between crosslinking points (Mc) = 3ρRT×1000000/E'

However, R = 8.31 [Jmol ^-1 K ^-1 ], E'and T were determined by dynamic viscoelasticity measurement, and ρ was determined by specific gravity measurement.

<Dynamic viscoelasticity measurement>

The adhesive solution was applied to a glossy surface of copper foil (BHY made by ENEOS, thickness 18 μm) so that the thickness after drying became 20 μm, and heated and cured at 170° C. for 3 hours. After removing the copper foil by etching the obtained sample, it was cut into strips having a width of 10 mm and a thickness of 20 μm, and the dynamic viscoelasticity was measured at a frequency of 110 Hz using a dynamic viscoelasticity measuring device DVA-220 manufactured by ITEI Measurement and Control Co., Ltd. did. The lowest storage modulus in the rubber-like flat region was E', and the temperature at that time was T.

<Measurement of specific gravity>

The adhesive solution was applied to a glossy surface of copper foil (BHY made by ENEOS, thickness 18 μm) so that the thickness after drying became 20 μm, and heated and cured at 170° C. for 3 hours. After the obtained sample was etched to remove the copper foil, the specific gravity of each sample at 23° C. was measured in accordance with JIS Z8807 8 (in-liquid weighing method) using the Shimadzu Corporation specific gravity measuring device SGM-300P.

(Production Example 1) Synthesis of polyamide imide resin (A1-1)

268.98 g (1.40 mol) of trimellitic anhydride and 315.32 g (1.26 mol) of 4,4'-diphenylmethane diisocyanate (MDI) as diisocyanate were added and dissolved in 710.09 g of N-methyl-2-pyrrolidone. . Thereafter, the reaction was carried out at 140° C. for 5 hours while stirring under a nitrogen stream, and then 169.07 g of dimethylacetamide was added, diluted, and cooled to room temperature, whereby a brown, viscous polyamide imide resin solution of 35% by mass of nonvolatile content ( A1-1) was obtained.

(Production Example 2) Synthesis of NBR copolymerized polyamide imide resin (A2-1)

Trimellitic anhydride 248.54 g (1.29 mol), NBR 225.40 g (0.06 mol), sebacic acid 8.49 g (0.04 mol), 4,4'-diphenylmethane diisocyanate (MDI) 353.85 g (1.41 mol) as diisocyanate And dissolved in 1069.59 g of dimethylacetamide. Thereafter, after reacting at 140° C. for 5 hours while stirring under a nitrogen stream, 594.22 g of dimethylacetamide was added, diluted, and cooled to room temperature, whereby a brown and viscous NBR copolymerized polyamide imide resin having a nonvolatile content of 30% by mass A solution (A2-1) was obtained.

(Production Example 3) Synthesis of NBR copolymerized polyamide imide resin (A2-2)

Trimellitic anhydride 256.61 g (1.34 mol), NBR 225.40 g (0.06 mol), 4,4'-diphenylmethane diisocyanate (MDI) 352.10 g (1.41 mol) as diisocyanate were added, and dimethylacetamide 1066.32 g Dissolved. Thereafter, after reacting at 140° C. for 5 hours while stirring under a nitrogen stream, 592.40 g of dimethylacetamide was added, diluted, and cooled to room temperature, whereby a brown and viscous NBR copolymer polyamide imide resin having a nonvolatile content of 30% by mass A solution (A2-2) was obtained.

(Production Example 4) Synthesis of NBR copolymerized polyamide imide resin (A2-3)

Trimellitic anhydride 262.26 g (1.37 mol), NBR 122.50 g (0.04 mol), and 4,4'-diphenylmethane diisocyanate (MDI) 353.85 g (1.41 mol) as diisocyanate were added to 921.23 g of dimethylacetamide. Dissolved. Thereafter, after reacting at 140°C for 5 hours while stirring under a nitrogen stream, 511.79 g of dimethylacetamide is added, diluted, and cooled to room temperature, whereby a brown and viscous NBR copolymer polyamide imide resin having a nonvolatile content of 30% by mass A solution (A2-3) was obtained.

(Production Example 5) Synthesis of NBR copolymerized polyamide imide resin (A2-4)

Trimellitic anhydride 256.61 g (1.34 mol), NBR 225.40 g (0.06 mol), and 4,4'-diaminodiphenylmethane 280.34 g (1.41 mol) as diamine were added, and dissolved in 1067.17 g of dimethylacetamide. Then, it was made to react at 80 degreeC for 4 hours, stirring under a nitrogen stream. Thereafter, after further reacting at 150°C for 10 hours, 592.87 g of dimethylacetamide was added, diluted, and cooled to room temperature to obtain a brown and viscous NBR copolymerized polyamide imide resin solution (A2- 4) was obtained.

(Comparative Production Example 1) Synthesis of NBR copolymerized polyamide imide resin (A2-5)

252.84 g (1.32 mol) of trimellitic anhydride, 294.00 g (0.08 mol) of NBR, and 353.85 g (1.41 mol) of 4,4'-diphenylmethane diisocyanate (MDI) as diisocyanate were added, and to 1164.35 g of dimethylacetamide Dissolved. Then, after reacting at 140°C for 5 hours while stirring under a nitrogen stream, 646.86 g of dimethylacetamide is added, diluted, and cooled to room temperature, whereby a brown and viscous NBR copolymer polyamide imide resin having a nonvolatile content of 30% by mass A solution (A2-5) was obtained.

(Comparative Production Example 2) Synthesis of NBR copolymerized polyamide imide resin (A2-6)

221.91 g (1.15 mol) of trimellitic anhydride, 122.50 g (0.04 mol) of NBR, 42.47 g (0.21 mol) of sebacic acid, 352.10 g (1.41 mol) of 4,4'-diphenylmethane diisocyanate (MDI) as diisocyanate And dissolved in 922.71 g of dimethylacetamide. Thereafter, after reacting at 140° C. for 5 hours while stirring under a nitrogen stream, 512.62 g of dimethylacetamide was added, diluted, and cooled to room temperature, whereby a brown and viscous NBR copolymer polyamide imide resin having a nonvolatile content of 30% by mass A solution (A2-6) was obtained.

Table 1 shows the details of Preparation Examples 1 to 5 and Comparative Preparation Examples 1 to 2.

(Examples 1 to 9 and Comparative Examples 1 to 7)

According to the mixing ratio shown in Table 2, polyamide imide resin (A1), NBR copolymerized polyamide imide resin (A2-1 to 6), epoxy resin (B), flame retardant (C), etc. were mixed to prepare an adhesive solution. It prepared and evaluated the said property.

Table 2 shows the details of the blending ratio and characteristic evaluation of the adhesive solutions of Examples 1 to 9 and Comparative Examples 1 to 7.

As is clear from Table 2, Examples 1 to 9 form a homogeneous phase while having a specific constituent component, and the copolymerization amount of the component (a) in the NBR copolymerized polyamide imide resin (A2) is 90 mol% or more. Moreover, since the mass ratio of A1/A2 was 0.1 or more and 1.0 or less, humidification solder heat resistance, insulation reliability, and outflow at the time of thermal compression bonding were good. Moreover, by making the mass ratio of (A1+A2)/B into 0.9 or more and 3.6 or less, the temporary adhesiveness of a B stage adhesive film was also favorable.

On the other hand, in Comparative Example 1, since the copolymerization amount of the component (c) in the NBR copolymerized polyamide imide resin (A2) was large, the adhesive composition formed a phase-separated structure of the islands, and the insulation reliability was poor. Since Comparative Example 2 does not contain the polyamide imide resin (A1) which does not contain NBR, leakage, insulation reliability, and ACF adhesion were poor. Further, the humidification solder heat resistance was also poor due to an increase in the molecular weight between the crosslinking points. In Comparative Example 3, since the A1/A2 weight ratio exceeded 1.0, adhesiveness was poor. In Comparative Example 4, since the copolymerization amount of sebacic acid in the NBR copolymerized polyamide imide resin (A2) was large and the copolymerization amount of the component (a) was small, the leakage and humidification solder heat resistance were poor. In Comparative Example 5, since the compounding amount of the liquid epoxy (B1) at room temperature was small, and the weight ratio of (A1+A2)/B exceeded 3.6, the temporary adhesion of the B-stage adhesive film was poor, and the NBR contained in the adhesive. Since the content rate was high, insulation reliability was poor. In Comparative Example 6, since the (A1+A2)/B weight ratio was less than 0.9, insulation reliability and humidification solder heat resistance were poor. Since Comparative Example 7 did not contain any NBR copolymerized polyamide imide resin (A2), adhesiveness, B-stage adhesive film embrittlement resistance, and B-stage adhesive film temporary adhesion were poor.

[Industrial availability]

The adhesive composition of the present invention has adhesiveness, insulation reliability, flame retardancy, B-stage adhesive film embrittlement resistance, improves humidification solder heat resistance, and has excellent spillability, B-stage adhesive film temporary adhesion, especially interlayer It is suitable for use in electronic components having an insulating layer or an adhesive layer. For this reason, in addition to being useful for overcoat inks for various electronic components such as flexible printed wiring boards, solder resist inks, and interlayer insulating films, it can be used in a wide range of electronic devices as paints, coatings, adhesives, etc., which greatly contributes to the industrial world. It is expected.

Claims (6)

(A1) polyamide imide resin not containing acrylonitrile butadiene rubber;
(A2) acrylonitrile butadiene rubber copolymerized polyamide imide resin; And
(B) An adhesive composition characterized by containing an epoxy resin having two or more epoxy groups per molecule as an essential component to form a homogeneous phase, and satisfying the following conditions (i) to (iii):
(i) the mass ratio of A1/A2 in the composition is 0.1 or more and 1.0 or less;
(ii) the mass ratio of (A1+A2)/B in the composition is 0.9 or more and 3.6 or less;
(iii) When (A2) is a resin containing the following components (a), (b) and (c) as a copolymerization component, and the structural units derived from the total acid components of (A2) are 100 mol% The proportion of the constituent units derived from the acid component is (a) 90-99 mol%, (c) 1-5 mol%:
(a) a polycarboxylic acid derivative having an acid anhydride group;
(b) an isocyanate compound or an amine compound;
(c) Acrylonitrile-butadiene rubber having carboxyl groups at both ends. The polycarboxylic acid derivative according to claim 1, wherein the valence of the polycarboxylic acid derivative of the component (a) is trivalent and/or tetravalent, the weight average molecular weight of the component (c) is 500 to 5000, and the ratio of the acrylonitrile moiety is 10. Adhesive composition, characterized in that it is in the range of -50% by mass. The adhesive composition according to claim 2, wherein (a) is a polycarboxylic acid derivative having an aromatic ring, and (b) is a diisocyanate compound having an aromatic ring or a diamine compound having an aromatic ring. The adhesive composition according to any one of claims 1 to 3, wherein when thermally cured at 150°C for 4 hr, the molecular weight (Mc) between crosslinking points determined by the following formula is 2000 or less:
Molecular weight between crosslinking points (Mc) = 3ρRT×1000000/E'
However, R = 8.31 [Jmol ^-1 K ^-1 ], E'and T are determined by dynamic viscoelasticity measurement, and ρ is determined by specific gravity measurement. The adhesive composition according to any one of claims 1 to 4, further comprising a phosphorus-based flame retardant (C). The adhesive composition according to any one of claims 1 to 5, wherein the numerical value obtained from the following formula is 1.5 or more and 7.0 or less:
Compounding ratio of epoxy resin solid content (parts by mass) to adhesive solid content (parts by mass) × epoxy equivalent [eq/t]/(polyamide imide resin (A1) solid content (parts by mass) to adhesive solid content (parts by mass)) Blending ratio × acid value of polyamide imide resin (A1) [eq/t] + NBR copolymerized polyamide imide resin (A2) solid content (parts by mass) to adhesive solid content (parts by mass) × NBR copolymerized polyamide The compounding ratio of the acid value of the imide resin (A2) [eq/t] + the solid content of the compound having a phenolic hydroxyl group to the solid content of the adhesive (parts by mass) × phenolic hydroxyl value [eq/t]}.