JPH11335652A - Film adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a film adhesive excellent in heat resistance and adhesion to inorganic materials and heat-resistant resin materials by mixing the solutions of two kinds of polyimide resins having specific structures with each other, casting the solution mixture and subsequently drying the cast film. SOLUTION: This film adhesive is obtained by mixing (A) the organic solvent solution of a polyimide resin comprising repeating units of formula I X1 comprises 5-40 mol.% of a group of formula II (R1 to R4 are each H, CH3 or the like), 50-95 mol.% of one to three kinds of divalent groups selected from a group of formula III [(n) is 1-50] or the like, and 0-40 mol.% of one or two kinds of divalent groups selected from a group of formula IV or the like; Y1 is one or two kinds of tetravalent groups selected from a group of formula V or the like} and having an imidation rate of >=95% with (B) the organic solvent solution of a polyimide resin comprising repeating units of formula VI (X2 comprises >=60 mol.% of one to four kinds of divalent groups selected from a group of formula III or the like and 0-40 mol.% of one or two kinds of divalent groups selected from a group of formula IV or the like; Y2 is one or two kinds of tetravalent groups selected from a group of formula V or the like) and having an imidation rate of >=95% in a resin A/B weight ratio of 0.1-10, casting the mixture and subsequently drying the cast film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film adhesive having excellent adhesion to inorganic substances such as metals and heat-resistant resins such as polyimides.

[0002]

2. Description of the Related Art Conventionally, as a heat-resistant thermocompression-bondable film adhesive, a polyamide-based or polyamide-imide-based thermoplastic heat-resistant resin, or an epoxy-based, phenol-based, or acrylic-based resin has been used. One using a thermosetting heat-resistant resin is known. However, polyamide-based and polyamide-imide-based resins have a drawback that the water absorption is increased due to the hydrophilic nature of the amide group, and there is a limit in using them for electronic applications requiring reliability. Thermosetting materials can be thermocompression bonded at a relatively low temperature, but in order to obtain heat resistance, a longer curing time is required and mass productivity is poor, there are many ionic impurities, and a large amount of volatilization occurs during heat curing. There were drawbacks such as the generation of minutes.

In order to solve these problems, a heat-resistant adhesive using a thermoplastic polyimide resin has been developed. This adhesive mainly shows excellent adhesiveness and adhesive workability to inorganic materials such as metals and ceramics, but its adhesiveness to heat-resistant resins such as polyimide, polyamideimide, polyamide, epoxy and phenol is not necessarily sufficient. Did not. For example, the surface treatment of the adherend is required, or it takes a long time to dry the solvent at the time of adhesion because it does not adhere unless the residual solvent in the adhesive film is left, and the precursor is amic acid or is sufficiently imidized. If not, the adhesive strength is weak, and if it is attempted to bond in this state, it takes time for foaming or imidization, and it is not always advantageous in terms of achieving both the adhesiveness and the bonding workability.

[0004]

SUMMARY OF THE INVENTION The present invention has been made as a result of intensive studies to obtain a film adhesive having excellent heat resistance and excellent adhesion to inorganic materials and heat-resistant resin materials. The present inventors have found that the above-mentioned problems can be solved by mixing two kinds of resin organic solvent solutions in a solution, and then casting and drying the mixed solution, thereby achieving the present invention.

[0005]

The polyimide resin composition of the present invention comprises an organic solvent solution of a polyimide resin A comprising a repeating unit of the general formula (A) and an organic solvent solution of a polyimide resin B comprising a repeating unit of the general formula (B). A polyimide resin composition obtained by mixing a solvent solution with A and B so that the weight ratio A / B of A and B is 0.1 to 10.

[0006]

Embedded image 中 In the formula, 5 to 40 mol% of X1 is the structural formula (1)
0 to 95 mol% is one to three kinds of divalent groups selected from structural formulas (2) to (5), and 0 to 40 mol% is one of structural formulas (6) to (8). The selected one or two kinds of divalent groups.

[0007]

Embedded image

[0008]

Embedded image

[0009]

Embedded image

[0010]

Embedded image

[0011]

Embedded image

[0012]

Embedded image

[0013]

Embedded image

[0014]

Embedded image Y1 is one or two kinds of tetravalent groups selected from structural formulas (9) to (13).

[0015]

Embedded image ｝

[0016]

Embedded image 中 In the formula, X2 represents at least 60 mol% of 1 to 4 divalent groups selected from structural formulas (2) to (5), and 0 to 40 mol% of structural formulas (6) to (8). 1-2) selected from
Types of divalent groups. Y2 is a structural formula (9) to (13)
And 1 to 2 types of tetravalent groups selected from ｝

The polyimide resin A is a polyimide resin having excellent adhesion to heat-resistant resin materials such as polyimide resin, polyamide imide resin, epoxy resin, and phenol resin. Introduction of a cyclohexane ring having an alicyclic structure is effective for increasing the adhesive strength to a heat-resistant resin.

The polyimide resin B is a polyimide resin having excellent adhesion to inorganic materials such as metals and ceramics.

In the present invention, the polyimide resin A and B are blended in a weight ratio A / B in the range of 0.1 to 10 so as to achieve both the adhesion to the inorganic material and the heat-resistant resin.
If the mixing ratio is out of the above range, the adhesion to either the inorganic material or the heat-resistant resin is undesirably reduced. Further, since the film adhesive of the present invention does not contain any material other than the polyimide resin, it exhibits the same heat resistance as the conventional polyimide resin.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The polyimide resin A of the present invention is obtained by reacting a polyamic acid obtained by reacting a diamine represented by the general formula (14) with a tetracarboxylic dianhydride represented by the general formula (15) in an organic solvent solution. It can be synthesized by dehydration ring closure in water.

[0021]

Embedded image {Where X1 corresponds to X1 in general formula (A)}

[0022]

Embedded image {Wherein Y1 corresponds to Y1 in general formula (A)}

Similarly, the polyimide resin B is also represented by the general formula (1)
It can be synthesized from the diamine represented by 6) and the acid dianhydride represented by the general formula (17).

[0024]

Embedded image {Wherein X1 corresponds to X2 in general formula (B)}

[0025]

Embedded image {Where Y1 corresponds to Y2 in general formula (B)}

It can also be synthesized by performing a decarboxylation reaction using diisocyanate instead of diamine.

Diamines wherein X1 in the general formula (14) is the general formula (1) are 4,4'-diaminodicyclohexylmethane, 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, 4,4'-diamine. Diamino-3,3'-diethyldicyclohexylmethane, 4,4'-diamino-
3,3 ', 5,5'-tetramethyldicyclohexylmethane, 4,4'-diamino-3,3', 5,5'-tetraethyldicyclohexylmethane, 4,4'-diamino-3,3'-dimethoxydicyclohexyl Methane, 4,
4'-diamino-3,3'-diethoxydicyclohexylmethane and the like, which contribute to adhesion to heat-resistant resins. If the ratio is less than 5 mol% of the total amine components, no effect can be obtained. Particularly, in the field where importance is attached to the heat-resistant resin, one of all amine components used for the polyimide resin A is used.
It is preferably at least 5 mol%. On the other hand, if the content is more than 40 mol%, the storage stability deteriorates such as gelation of the solution, which is not preferable. Among them, the use of 4,4'-diaminodicyclohexylmethane is preferable from the viewpoint of both adhesiveness and heat resistance.

X1 in the general formula (14) or the general formula (1
6) The diamine in which X2 is represented by the general formula (2) is 1,3-bis (3-aminopropyl) tetramethylsiloxane or α, ω-bis (3-aminopropyl) polydimethylsiloxane, and the obtained polyamic acid And the solubility of polyimide resin in organic solvents, thermoplasticity, and adhesion. The use of these diamines can lower the glass transition temperature, and is particularly suitable for applications requiring low-temperature bonding. The amount ratio is preferably 5 mol% or more of the total amine component from the viewpoint of solubility and thermoplasticity. From the viewpoint of heat resistance, it is more preferable to use it in the range of 5 to 50 mol%. In particular, when 1,3-bis (3-aminopropyl) tetramethylsiloxane is used, it is possible to improve solubility, thermoplasticity, and adhesion without impairing heat resistance.

X1 in the general formula (14) or the general formula (1
The diamine wherein X2 in 6) is represented by the general formula (3) is 4,4 ′
-Methylenedi-O-toluidine, 4,4'-methylenedi-2,6-xylidine, 4,4'-methylenedi-2,6
-Diethylaniline, 4,4'-diamino-3,3'-
Diethyl-5,5'-dimethyldiphenylmethane or the like contributes to the solubility and heat resistance of the obtained polyamic acid and polyimide resin in organic solvents. In addition, by using a diamine having this structure, a polyimide resin soluble in an organic solvent having a glass transition temperature of 250 ° C. or more can be easily synthesized, and is particularly suitable for applications requiring an elastic modulus at a high temperature. I have. The amount ratio is preferably 10 mol% or more of all amine components from the viewpoint of solubility and heat resistance. 4,4′- wherein R1 to R4 are all hydrogen atoms
Diaminodiphenylmethane cannot be used because it greatly reduces the solubility of the polyimide resin in organic solvents.

X1 in the general formula (14) or the general formula (1
6) The diamine wherein X2 is a general formula (4) is 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 2,2-bis (4- (3-aminophenoxy) phenyl) propane, 2,2-bis (4- (4-aminophenoxy) phenyl) hexafluoropropane, 2,2-
Bis (4- (3-aminophenoxy) phenyl) hexafluoropropane and the like contribute to the solubility and adhesion of the obtained polyamic acid and polyimide resin. The amount ratio is preferably 10 mol% or more of all amine components from the viewpoint of solubility and heat resistance.

X1 of the general formula (14) or the general formula (1
6) The diamine wherein X2 is represented by the general formula (5) is 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4
-Aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, etc., which contribute to the solubility and heat resistance of the obtained polyamic acid and polyimide resin.
The amount ratio is 10% of all amine components from the viewpoint of solubility and heat resistance.
It is preferable to use at least mol%. In particular, when 1,3-bis (3-aminophenoxy) benzene is used, the solubility is high.
It is preferable because the adhesiveness can be improved.

X1 of the general formula (14) or the general formula (1
The diamine wherein X2 of 6) is a general formula (6) is 3,3′-
Dihydroxy-4,4'-diaminobiphenyl, 3,
3′-dimethoxy-4,4′-diaminobiphenyl,
3,3 ', 5,5'-Tetramethoxy-4,4'-diaminobiphenyl, 3,3'-diethoxy-4,4'-diaminobiphenyl and the like contribute to the adhesion of the obtained polyimide resin. The amount ratio is preferably 1 mol% or more of the total amine component from the viewpoint of adhesiveness, but if it is 30 mol% or more, the solubility in an organic solvent is undesirably reduced. In particular, when 3,3′-dihydroxy-4,4′-diaminobiphenyl is used, the initial adhesiveness is improved, and at the same time, even if an accelerated test such as a heat treatment or a moisture absorption treatment is performed, the adhesive strength is not reduced and the reliability is improved. Therefore, it is preferable.

X1 in the general formula (14) or the general formula (1
6) X2 represented by the general formulas (7) and (8) is 3,4′-diaminodiphenyl ether, 4,4′-diamine.
Diaminodiphenyl ether, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,5 diaminotoluene, 2,4 diaminotoluene, 4,6-dimethyl-m-phenylenediamine, 2,
5-dimethyl-p-phenylenediamine, 2,4,6-
Trimethyl-m-phenylenediamine, 3,5 diaminobenzoic acid, etc., which can be used particularly for applications requiring heat resistance. However, when the content is 40 mol% or more of the total amine components, the solubility in an organic solvent decreases, which is not preferable.

In the polyimide resin A, at least 50 mol% of X1 must be a divalent group selected from structural formulas (2) to (5) from the viewpoint of solubility. For the same reason, the sum of the divalent groups selected from the structural formulas (6) to (8) must not exceed 40 mol% of X1.

Similarly, from the viewpoint of solubility, the sum of the divalent groups selected from (6) to (8) must not exceed 40 mol% of X2 in the polyimide resin B (2) to (2). 5)
The sum of the divalent groups selected from the above is 60 mol% of X2
It is necessary.

The acid dianhydride used in the present invention is pyromellitic anhydride (hereinafter abbreviated as PMDA), 3,3 ', 4,4'-
Biphenyltetracarboxylic dianhydride (hereinafter abbreviated as BPDA), 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (hereinafter abbreviated as BTDA), 4,4′-
Oxydiphthalic dianhydride (hereinafter abbreviated as ODPA),
3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride (hereinafter abbreviated as DSDA). Particularly for applications requiring heat resistance and adhesiveness, it is preferable to use BPDA and BTDA together.
Is preferably in the range of 1 to 20 in molar ratio BPDA / BTDA. If the ratio is larger or smaller than this, the solubility of the resulting polyimide resin is undesirably reduced.
In particular, in applications where low-temperature adhesion is required, ODP
It is preferable to use A.

The equivalent ratio between the acidic component and the amine component in the polymerization reaction is an important factor that determines the molecular weight of the resulting polyamic acid. It is well known that there is a correlation between the molecular weight and physical properties of a polymer, especially the number average molecular weight and mechanical properties. The higher the number average molecular weight, the better the mechanical properties. Therefore, in order to obtain practically excellent strength, it is necessary to have a high molecular weight to some extent. In the present invention, the equivalent ratio r between the acidic component and the amine component is preferably a molar ratio of 0.95 ≦ r ≦ 1.05. 0.97 ≦ r ≦ 1.0
The range of 3 is more preferable in terms of both mechanical strength and heat resistance.

The reaction between the tetracarboxylic dianhydride and the diamine is carried out by a known method in an aprotic polar solvent. Aprotic polar solvents include N, N-dimethylformamide (DMF), N, N-dimethylacetamide (D
MAC), N-methyl-2-pyrrolidone (NMP), tetrahydrofuran (THF), diglyme, cyclohexanone, gamma-butyrolactone (GBL), 1,4-
And dioxane (1,4-DO). As the aprotic polar solvent, only one kind may be used, or two or more kinds may be used as a mixture. At this time, a non-polar solvent compatible with the aprotic polar solvent may be mixed and used. Aromatic hydrocarbons such as toluene, xylene, and solvent naphtha are often used. The proportion of the non-polar solvent in the mixed solvent is preferably 30% by weight or less.
This is because if the nonpolar solvent is 30% by weight or more, the solvent power of the solvent may be reduced and polyamic acid may be precipitated. The reaction between the tetracarboxylic dianhydride and the diamine is
The well-dried diamine component is dissolved in the above-mentioned dehydrated and purified reaction solvent, and the ring closure ratio is 98%, more preferably 99%.
The above-mentioned well-dried tetracarboxylic dianhydride is added to proceed the reaction.

The polyamic acid solution thus obtained is subsequently heat-dehydrated and cyclized in an organic solvent to give imidized polyimide. Since the water generated by the imidization reaction interferes with the ring closure reaction, an organic solvent incompatible with water is added to the system and azeotroped, and the system is removed from the system using a device such as a Dean-Stark tube. To be discharged. Dichlorobenzene is known as an organic solvent incompatible with water,
For the purpose of electronics, the above-mentioned aromatic hydrocarbon is preferably used because there is a possibility that a chlorine component may be mixed.
Further, it does not prevent the use of compounds such as acetic anhydride, β-picoline, and pyridine as a catalyst for the imidization reaction.

In the present invention, the higher the degree of imide ring closure, the better the degree of imidization. If the rate of imidization is low, imidization occurs due to heat during use and water is undesirably generated, so that 95% or more, more preferably 98% or more. It is desirable that an imidization ratio is achieved. If the imidation ratio of either of the polyimide resins A and B before mixing is lower than 95%, the adhesion to inorganic substances and the heat-resistant resin is undesirably reduced. Although this mechanism has not been elucidated, it is considered that this is because the phase structure of the polyimides A and B in the film adhesive changes.

In the present invention, the obtained polyimide resin solution can be used as it is. It is also possible to throw this solution into a poor solvent to reprecipitate and precipitate the polyimide resin to remove and purify the unreacted monomer, and to dry and dissolve it again in an organic solvent for use. Especially volatiles and impurities,
In applications in which foreign substances are disliked, it is preferable to filter and use the polyimide solution thus produced.

The mixing of the two kinds of polyimide resins can be easily performed by stirring in a solution, but in this case, the solvent used must be one that dissolves both polyimide resins.

Various additives such as a leveling agent, a leveling agent and a defoaming agent for improving the surface smoothness of the film can be added to the resin solution as required. In addition, an aromatic hydrocarbon-based solvent can be used within a range in which the solvent is uniformly dissolved in order to adjust the evaporation rate of the solvent.

In order to make the resin solution into a film adhesive in the present invention, it is obtained by casting or applying the resin solution.
For example, using a heat-resistant film substrate as a support, a film layer is similarly formed on one or both surfaces thereof, and used as a film adhesive together with the support, or flow onto a release sheet such as a roll, a metal sheet, or a polyester sheet. The film can be obtained by a method such as forming a film with a coater or a roll coater, heating and drying, and then peeling to form a single-layer film adhesive. The heat-resistant film substrate used in the present invention is such that the polyimide resin film has a small coefficient of thermal expansion and is excellent in dimensional stability against temperature changes, is flexible and easy to handle, and has an adhesive force with the resin of the present invention. Is preferable in that it is excellent. Especially the glass transition temperature
A polyimide resin having a temperature of 350 ° C. or higher is excellent in workability and stability in a step of drying a coating varnish.

The base film used for producing a single-layer film adhesive is required to have the heat resistance of the release agent and the base material not lower than the drying temperature. The substrate is preferably a polyethylene terephthalate film, a polyethylene naphthalate film, a polyimide film, a polyphenylene sulfide film, an aluminum foil, or a stainless steel film. As the release agent, a hydrocarbon-based release agent has insufficient heat resistance, and is preferably a heat-resistant resin such as silicone, silicone-modified epoxy, or fluororesin. Application and drying of resin varnish
An apparatus in which a coating facility such as a flow coater or a roll coater is combined with a hot-air drying furnace can be used.
After applying the resin varnish to the support, the resin varnish is guided to a hot-air drying oven and dried at a temperature and air volume sufficient to evaporate the solvent of the varnish. The method of using the film adhesive of the present invention is not particularly limited, but it can be used as an adhesive tape, for example, by cutting into a predetermined shape and bonding by thermocompression bonding with a heated heat block.

The film adhesive of the present invention is a film adhesive mainly composed of a substantially completely imidized polyimide resin having a specific structure. By mixing two types of solvent-soluble polyimide resins having different structures in a solution to form a film, it became possible to draw out the excellent points of each polyimide resin. It is a highly versatile film adhesive with excellent adhesion to various adherends, such as inorganic substances such as metals and ceramics, and heat-resistant resins such as polyimide, polyamide imide, polyamide, epoxy and phenol. Further, since the film adhesive of the present invention is thermoplastic, it can be thermocompression-bonded in a short time of 1 second or less, and has significantly superior bonding workability as compared with a thermosetting adhesive involving a chemical reaction. is there. In addition, since it is in the form of a film, adhesion workability,
Excellent dimensional accuracy of bonded part.

[0047]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Abbreviations in Examples and Comparative Examples are as follows. PI: Polyimide PAA: Polyamic acid HM: 4,4'-diaminodicyclohexylmethane MHM: 4,4'-diamino-3,3'dimethyldicyclohexylmethane APDS: 1,3-bis (3-aminopropyl) tetramethylsiloxane APPS : Α, ω-bis (3-aminopropyl) polydimethylsiloxane (average molecular weight: 837) MDT: 4,4′-methylenedi-O-toluidine MDX: 4,4′-methylenedi-2,6-xylidine DDM: 4, 4'-Diaminodiphenylmethane BAPP: 2,2-bis (4- (4-aminophenoxy) phenyl) propane APB: 1,3-bis (3-aminophenoxy) benzene HAB: 3,3'-dihydroxy-4,4 '-Diaminobiphenyl 34' DDE: 3,4'-diaminodiphenyl ether 25D X: 2,5-dimethyl-p-phenylenediamine BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride BTDA: 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride ODPA: 4,4'-oxydiphthalic dianhydride DSDA: 4,4'-diphenylsulfonetetracarboxylic dianhydride PMDA: pyromellitic anhydride NMP: N-methyl-2-pyrrolidone DMAc: N, N-dimethylacetamide GBL: gamma-butyrolactone

(Synthesis of polyimide resin PI-1) 349.5 g of dehydrated and purified GBL was placed in a four-necked flask equipped with a dry nitrogen gas inlet tube, a cooler, a thermometer, and a stirrer. Stirred. Next, 34.792 g (0.060 mol) of APDS, which is an amine component, and 12.380 g (0.14 mol) of HM were added.
The system was heated to 60 ° C. and stirred until uniform. After homogeneously dissolving, the system was cooled to 5 ° C. in an ice water bath, and the acid component OD
62.044 g (0.2 mol) of PA was powdered as 10
Then, stirring was continued for 5 hours to obtain a polyamic acid solution. During this time, the flask was kept at 5 ° C. Thereafter, the nitrogen gas inlet tube and the condenser were removed, a Dean-Stark tube filled with toluene was attached to the flask, and 87.4 g of toluene was added to the system. The system was heated by replacing the ice water bath with an oil bath, and the generated water was removed from the system. After heating for 4 hours, no water was generated from the system. After cooling, the reaction solution was poured into a large amount of methanol to precipitate a polyimide resin. After filtering the solid content, the solid was dried under reduced pressure at 80 ° C. for 12 hours to obtain a solid resin. When the infrared absorption spectrum was measured by the KBr tablet method, an absorption of 5.60 μm derived from the cyclic imide bond was recognized, but an absorption of 6.06 μm derived from the amide bond could not be recognized. 100% imidization was confirmed.

(Polyimide resins PI-2 to 35, 10
Synthesis of 1, 102) The blending of the amine component and the acid component shown in Table 1 was carried out in the same manner as in the above-mentioned synthesis of PI-1.
5, 101 and 102 were synthesized. It was confirmed that these polyimide resins were almost 100% imidized similarly to PI-1.

[0050]

[Table 1]

[0051]

[Table 2]

[0052]

[Table 3]

[0053]

[Table 4]

(Synthesis of polyimide resins PI-103 to 108)
Synthesis of I-103 to 108 was attempted.

(Synthesis of polyimide resin PI-109) 349.5 g of dehydrated and purified GBL was placed in a four-necked flask equipped with a dry nitrogen gas inlet tube, a cooler, a thermometer, and a stirrer.
The mixture was vigorously stirred for 10 minutes while flowing nitrogen gas. Next, 34.792 g (0.060) of APDS which is an amine component
Mol) and 12.380 g (0.14 mol) of HM, and the system was heated to 60 ° C. and stirred until uniform. After homogeneously dissolving, the system was cooled to 5 ° C. in an ice water bath, and 62.44 g (0.2 mol) of ODPA as an acid component was added over 10 minutes while keeping the powdery state. I got During this time, the flask was kept at 5 ° C. Thereafter, the nitrogen gas inlet tube and the condenser were removed, a Dean-Stark tube filled with toluene was attached to the flask, and 87.4 g of toluene was added to the system. The system was heated by replacing the ice water bath with an oil bath, and the generated water was removed from the system. After heating for 2 hours, the dehydration reaction was not completed but was cooled. After cooling, the reaction solution was poured into a large amount of methanol to precipitate a polyimide resin. After filtering the solids, 12
After drying under reduced pressure for a time, a solid resin was obtained. When the infrared absorption spectrum was measured by the KBr tablet method, an absorption of 5.60 μm derived from the cyclic imide bond and 6.06 μm derived from the amide bond were observed. When calculated from the absorbance ratio, the imidization ratio of this resin was about 75%.

(Synthesis of Polyimide Resin PI-110) PI-110 was synthesized in the same manner as in the synthesis of PI-109 with the composition shown in Table 1. When the same evaluation was performed, the imidation ratio of this resin was about 80%.

(Synthesis of Polyamic Acid Resin PAA-1) 355.6 g of dehydrated and purified NMP was placed in a four-necked flask equipped with a dry nitrogen gas inlet tube, a cooler, a thermometer, and a stirrer.
The mixture was vigorously stirred for 10 minutes while flowing nitrogen gas. Next, 20.350 g (0.080 mol) of MDX as an amine component, 10.317 g (0.05 mol) of HM, and BAPP
12.315 g (0.030 mol), APDS 9.94
1 g (0.04 mol) was charged, and the system was heated to 60 ° C. and stirred until uniform. After dissolving uniformly, the system was cooled to 5 ° C. in an ice water bath, and 51.900 g of BPDA as an acid component was used.
(0.176 mol), BTDA 6.316 g (0.02
(0 mol) in the form of a powder over 10 minutes, followed by stirring for 5 hours to obtain a uniform polyamic acid solution.

(Synthesis of Polyamic Acid Resin PAA-2) PAA-2 was synthesized in the same manner as in the synthesis of PAA-1 with the composition shown in Table 1.

Example 1 In a glass flask, 20 g of a polyimide resin PI-1 solution (solid content concentration: 20%) and PI
180 g of the -22 solution (solid content: 20%) was added and stirred sufficiently to obtain a uniform blend solution. This solution was applied to a polyimide film (trade name: Upilex SGA, thickness: 50 μm, manufactured by Ube Industries, Ltd.) using a reverse roll coater, dried at 250 ° C. for 30 minutes, and the thickness of the adhesive layer was about 3 μm.
A 0 μm film adhesive was obtained. This film adhesive was thermocompression-bonded to a 42-alloy plate, which is a kind of stainless steel, to produce a test piece. The bonding temperature is 320 ° C. The pressure bonding time was 1 second, and the pressure applied to the bonding surface was 4 kgf / cm ² . The 180 degree peel strength of this test piece was 1.7 kgf /
cm. Under exactly the same conditions, an inorganic material such as copper foil, aluminum foil, silicon wafer, an organic heat-resistant material polyimide film (trade name Kapton K, manufactured by Dupont Toray) and a polyimide semiconductor protective film (trade name Sumiresin) Excel CRC, manufactured by Sumitomo Bakelite Co., Ltd.) and a cured resin plate of a phenolic resin (trade name: Sumilite Resin PR, manufactured by Sumitomo Durez Co., Ltd.) as a thermosetting resin and an epoxy resin (trade name: Epicoat, Yuka (Shell Epoxy Co., Ltd.) was tested for adhesion to a cured resin plate. Table 2 shows the results. It shows a strong adhesive force of 1.0 kgf / cm or more to all the adherends, and it can be seen that the adhesiveness to inorganic and organic materials is compatible.

(Examples 2 to 44) Using the same method as in Example 1, the film adhesives of Examples 2 to 44 were prepared with the combinations of polyimide resins and the ratios shown in Table 2. Table 2 shows the results of the same adhesion evaluation as in Example 1. All formulations showed good adhesion to all adherents.

[0061]

[Table 5]

[0062]

[Table 6]

[0063]

[Table 7]

(Comparative Example) Using the same method as in Example 1, the film adhesives of Comparative Examples 1 to 28 were tried to be prepared by using the combination of the polyimide resin or the polyamic acid resin shown in Table 3 and the amount ratio. Table 3 shows the results of the same adhesive evaluation as in Example 1 for films that could be formed.

[0065]

[Table 8]

[0066]

[Table 9]

(Comparative Examples 1 to 6)
When a single kind of polyimide resin was used without being mixed, the adhesive strength to either or both of the inorganic material and the heat-resistant material was reduced.

(Comparative Examples 7 to 10) As in Comparative Examples 7 to 10, when the mixing ratio of the two kinds of polyimide resins deviated from the above-mentioned ratio, the adhesive strength to either the inorganic material or the heat-resistant material was reduced.

(Comparative Examples 11 to 16) Even when two kinds of polyimide resins are mixed as in Comparative Examples 11 to 16, when any one of the polyimide resins is different from the above-mentioned structure, an inorganic material, heat-resistant Adhesion to any of the conductive materials decreased.

(Comparative Examples 17 to 22) As in Comparative Examples 17 to 22, when one of the two kinds of polyimide resins is different from that having the above structure, or when the solubility is out of the above range, the solubility is lowered. Cannot be mixed and formed into a film.

(Comparative Examples 23 to 28) As in Comparative Examples 23 to 28, imidation of either or both of the two kinds of polyimide resins was insufficient, or a polyimide resin precursor or a polyamic acid resin was used. When the imidation ratio is out of the above range, the adhesive strength to both the inorganic material and the heat-resistant material is reduced.

[0072]

According to the present invention, the main constituent components of a polyimide resin are excellent in adhesion to both inorganic materials such as metals and ceramics and heat-resistant resin materials such as polyimide, polyamide imide, polyamide, epoxy and phenol. It is possible to provide a film adhesive. Further, it is excellent in heat resistance, and even when bonding at a high temperature, it is possible to minimize bonding failure and appearance failure due to gas generated by decomposition or the like. Also, since it can be used as a tack-free film, it is very effective when continuous workability and a clean environment are required. For this reason, it is extremely useful industrially as a material for electronics requiring high reliability and heat resistance.

Claims (13)

[Claims] 1. An organic solvent solution of a polyimide resin A comprising a repeating unit of the general formula (A) having an imidization ratio of 95% or more and an imidation ratio of 95 comprising a repeating unit of the general formula (B).
% Or more of an organic solvent solution of the polyimide resin B, and the mixture is cast so that the weight ratio A / B of A and B is 0.1 to 10;
Film adhesive obtained by drying. Embedded image 中 In the formula, 5 to 40 mol% of X1 is the structural formula (1)
0 to 95 mol% is one to three kinds of divalent groups selected from structural formulas (2) to (5), and 0 to 40 mol% is one of structural formulas (6) to (8). The selected one or two kinds of divalent groups. Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image Embedded image Y1 is one or two kinds of tetravalent groups selected from structural formulas (9) to (13). Embedded image ｝ 中 In the formula, X2 represents at least 60 mol% of 1 to 4 kinds of divalent groups selected from the structural formulas (2) to (5), and 0 to 40 mol% of the structural formulas (6) to (8). 1-2) selected from
Types of divalent groups. Y2 is a structural formula (9) to (13)
And 1 to 2 types of tetravalent groups selected from ｝ 2. The film adhesive according to claim 1, wherein 5 to 95 mol% of X1 of the polyimide resin A is the structural formula (2). 3. The film adhesive according to claim 1, wherein 10 to 95 mol% of X1 of the polyimide resin A is the structural formula (3). 4. The film adhesive according to claim 1, wherein 10 to 95 mol% of X1 of the polyimide resin A is the structural formula (4). 5. The film adhesive according to claim 1, wherein 10 to 95 mol% of X1 of the polyimide resin A is the structural formula (5). 6. The film adhesive according to claim 1, wherein 1 to 30 mol% of X1 of the polyimide resin A is a structural formula (6). 7. The film adhesive according to claim 1, wherein at least 5 mol% of X2 of the polyimide resin B has the structural formula (2). 8. The film adhesive according to claim 1, wherein at least 10 mol% of X2 of the polyimide resin B has the structural formula (3). 9. The film adhesive according to claim 1, wherein at least 10 mol% of X2 of the polyimide resin B is a structural formula (4). 10. 10 mol% of X2 of polyimide resin B
The film adhesive according to claim 1, wherein the above is the structural formula (5). 11. The film adhesive according to claim 1, wherein 1 to 30 mol% of X2 of the polyimide resin B is a structural formula (6). 12. Y1 of the polyimide resin A and / or Y2 of the polyimide resin B are represented by the structural formulas (10) and (11).
The film adhesive according to any one of claims 1 to 11, comprising a molar ratio (10) / (11) of 1 to 20. 13. The film adhesive according to claim 1, wherein Y1 of the polyimide resin A and / or Y2 of the polyimide resin B have a structural formula (12).