JPH0745650B2 - Heat resistant adhesive composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a heat-resistant adhesive composition having excellent heat resistance, moisture resistance, electrical characteristics, and processability.

(Prior Art) In recent years, the demand for FPCs (flexible printed wiring boards) that are light and can be mounted so as to three-dimensionally perform wiring or function has increased with the increase in density of electronic devices and their miniaturization.

Especially in polyimide film based FPC, high temperature (2
There are applications where adhesive strength at 60 to 300 ° C) is required, and the adhesive is required to have a film forming ability as a double-sided adhesive tape, be easily B-stageable, and have good storage stability. It

However, adhesion and heat resistance to polyimide film,
It was extremely difficult to combine workability and the like.

Conventionally, nitrile rubber has been used as an adhesive for FPC (JP-A-51-1).
35936, JP 57-3877), polyamide-based (JP 5
4-125285), polyester-based (JP-A-50-16866,
Many proposals have been made such as JP-A-54-7441) and polyacrylic resins. However, under the present circumstances, none of them satisfy the adhesive strength at high temperature and have a function as a double-sided adhesive tape.

(Problems to be Solved by the Invention) The present invention has been made in view of the above circumstances, and is excellent in heat resistance, moisture resistance, adhesiveness, electrical characteristics, storage stability, and processability, and has practical utility. It is intended to provide a large heat resistant adhesive composition.

[Structure of the Invention] (Means and Actions for Solving Problems) As a result of intensive studies to achieve the above object, the present inventors have found that by using an addition reaction type polyimide and an acrylic elastomer in combination, The present invention has been completed by finding out that the above object is achieved. That is, the present invention includes (A) an acrylic elastomer having one or more functional groups selected from an epoxy group, a carboxyl group and a hydroxyl group, and (B) (a) N, N of an unsaturated dicarboxylic acid. A reaction product of a ′ -bisimide compound, (b) aminophenol, and (c) aniline or an aniline derivative,
A heat-resistant adhesive composition comprising (C) an epoxy compound and (D) a curing accelerator as essential components. Then, the acrylic elastomer is used as a resin component [(A) + (B)
+ (C)] in a proportion of 5 to 50% by weight and a curing accelerator in a proportion of 0.01 to 5% by weight with respect to the epoxy resin.

Hereinafter, the present invention will be described in more detail.

As the acrylic elastomer (A) used in the present invention,
A compound having one or more functional groups selected from an epoxy group, a carboxyl group and a hydroxyl group, and specific compounds include, for example, ARONTAC S-1511L,
S-1511X, S-10015, S-1017 (Toa Gosei Kagaku Co., Ltd., trade name), AR-51 (Nippon Zeon Co., Ltd. trade name), Baxtite PA-501, PA-502 (Nippon Mektron Co., Ltd., Product name), Teisan Resin WSO23, SG51, SG70L, SG80, SG90, SG2
80 (manufactured by Teikoku Kagaku Sangyo Co., Ltd.) and the like can be mentioned, and these are used alone or in combination of two or more.

The (B) reaction product used in the present invention is an addition reaction product of (a) an N, N′-bisimide compound of an unsaturated dicarboxylic acid, (b) aminophenol, and (c) aniline or an aniline derivative. (A) N, N'- of unsaturated dicarboxylic acid
As the bisimide compound, a compound having the following general formula is used.

However, in the formula, R ¹ represents a divalent group having at least 2 carbon atoms, and R ² represents a divalent group containing a double bond between carbon atoms. That is, as R ¹ , a linear or branched alkylene group, a cycloalkylene group having a ring of 5 to 6 carbon atoms, a heterocyclic group containing at least one of oxygen, nitrogen or sulfur atom, a benzene group Alternatively, a plurality of benzene groups and alicyclic groups bonded by —NHCO—, —NR ⁶ —, —SiO ⁶ R ⁷ — or —SO ₂ — as well as polycyclic aromatic groups can be mentioned ( However, R ⁶ and R ⁷ represent an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having a ring having 5 to 6 carbon atoms, and a benzene group). Examples of R ² , that is, a divalent group containing a double bond between carbon atoms, include a maleic acid residue, a citraconic acid residue, and a tetrahydrophthalic acid residue. Therefore, specific examples of the N, N′-bisimide compound of unsaturated dicarboxylic acid satisfying the above-mentioned conditions of R ¹ and R ² include the following, which are one kind or a mixture of two or more kinds. To use as.

Maleic acid N, N'-4,4'-diphenylmethane bisimide, maleic acid N, N'-4,4'-diphenyl ether bisimide, maleic acid N, N'-paraphenylene bisimide, maleic acid N, N ' -Benzidine bisimide, maleic acid N, N'-meta-xylene bisimide, maleic acid N, N '
-1,5-naphthalene-bisimide, maleic acid N, N'-4,
4'-diphenylsulfone-bisimide, maleic acid N,
N'-2,2'-4,4'-dimethylene-cyclohexane-bisimide, maleic acid N, N'-4,4'-dicyclohexyl-methanebisimide, maleic acid N, N'-4,4'-diphenyl Cyclohexane-bisimide, maleic acid N, N'-
4,4'-diphenyl-phenylamine-bisimide, maleic acid N, N'-4,4'-diphenyl-diphenylsilane-bisimide, maleic acid N, N'-4,4'-diphenylsulfur-bisimide, maleic acid N, N'-2,2 '-(4,4'-
Diphenyl) -propane-bisimide, maleic acid N,
N'-metaphenylene-bisimide, maleic acid N, N'-
3,3 '-(N, N'-metaphenylene-bisbenzamide)
Bisimide and the like.

As the (b) aminophenol which is the next component of the reaction product, one having the following general formula is used.

However, in the formula, R ³ represents a hydrogen atom, a halogen atom or an alkyl group. Specific compounds include the following, and these are used as one type or as a mixed system of two or more types. o-aminophenol, m-aminophenol, p
-Aminophenol, 2-amino-4-chlorophenol, 2-amino-4-methylphenol and the like.

As the other component of the reaction product, (c) aniline or an aniline-derived pair, one having the following general formula is used.

However, in the formula, R ⁴ and R ⁵ represent a hydrogen atom, an alkyl group, a halogen atom, -OCH ₃ , -OC ₂ H ₅ , -COOCH ₃ , -COOC ₂ H ₅ or the like group which does not contain active hydrogen. As specific compounds, aniline, o-chloroaniline, m-toluidine,
Any methyl-p-aminobenzoic acid ester or the like can be used as long as it does not contain active hydrogen in the nuclear substituent of aniline.

As the epoxy compound having at least two epoxy groups in the molecule (C) used in the present invention, for example, Epibis type compound based on bisphenol A, Epicoat 82
8 (Shell Chemical Co., Ltd., trade name), alkyl-modified Epicron 800, Epicron 4050 (Dainippon Ink and Chemicals Co., Ltd. trade name), Shodyne (Showa Denko KK, trade name), Araldite CY- Glycidyl ester compounds such as 183 (Ciba Geigy, trade name), Novolac-type Epicoat 154 (Shell Chemical Co., trade name), DEN43
1, DEN438 (Dow Chemical Co., trade name), cresol novolac type ECN1280, ECN1235 (Ciba Geigy Co.,
Product name), urethane-modified EPU-6, EPU-10 (trade name, manufactured by Asahi Denka Co., Ltd.). Epoxy resins represented by the following formulas (1) to (3) can also be used.

In addition to the above-mentioned epoxy resins, various kinds of epoxy resins can be used. In short, all kinds of epoxy resins can be used if the conditions are appropriately selected.

Examples of the (D) curing accelerator used in the present invention include dicyandiamide, Epicure YPH-201 (trade name of Yuka Shell Epoxy Co., Ltd.), BF ₃ imidazole complex AC-4B series (trade name of Maruzen Petroleum Co., Ltd.), Imidazole derivative, 4,
Aromatic amines such as 4'-diaminodiphenyl sulfone may be used, and these may be used alone or in admixture of two or more.

The heat-resistant adhesive composition of the present invention contains an acrylic elastomer, a reaction product, an epoxy compound, and a curing accelerator as essential components, and the blending ratios thereof will be described. The composition of the present invention is prepared by reacting an N, N′-bisimide compound of an unsaturated dicarboxylic acid with an aminophenol and an aniline or an aniline derivative in a solvent-free or inert solvent, and then adding an epoxy compound and an acrylic elastomer to the reaction. To manufacture. It is preferable that the total amount of aminophenol and aniline or an aniline derivative is 0.1 to 1.0 mol and the epoxy compound is 0.2 to 2.0 equivalents per 1 mol of the N, N'-bisimide compound of the unsaturated dicarboxylic acid. The reason is that when the total amount of aminophenol and aniline or an aniline derivative exceeds 1.0 mol, an epoxy compound corresponding to the excess must be blended, and as a result,
This is because the heat resistance, which is the greatest feature of the adhesive composition, is impaired. Further, if it is less than 0.1 mol, the softening temperature is high and the solubility is deteriorated so that it cannot be dissolved in a low boiling point solvent, which is not preferable.
This is because when the epoxy compound is less than 0.2 equivalent, the moisture resistance becomes poor, and when it exceeds 2.0 equivalent, the heat resistance is impaired.
The mixing ratio of the reaction product (B) and the epoxy compound (C) to the acrylic elastomer (A) depends on the resin component [(A)
+ (B) + (C)] to 5 acrylic acrylic elastomers
It is preferable to mix such that the content is ˜50% by weight. This is because if the content is less than 5% by weight, the film-forming property becomes poor, and if it exceeds 50% by weight, sufficient heat resistance cannot be obtained, which is not preferable. Further, it is desirable that the curing accelerator is blended in an amount of 0.01 to 5% by weight based on the epoxy compound. If the blending amount is less than 0.01% by weight, curing is not accelerated and curing occurs, and if it exceeds 5% by weight, storage stability and workability are deteriorated, which is not preferable.

The present invention, the heat-resistant adhesive composition, the compounding order of each component described above, the reaction temperature, the solvent can be appropriately selected,
It is not particularly limited. Hereinafter, production examples of typical adhesives will be described.

An N, N′-bisimide compound of unsaturated dicarboxylic acid, aminophenol and aniline or an aniline derivative are charged into a reaction vessel at a predetermined ratio. The temperature of the reaction system is 100-200
Raise the temperature to ℃ to melt the contents and proceed the reaction until it shows a predetermined viscosity, then lower the temperature to 80-150 ℃, add a predetermined amount of epoxy compound and continue the reaction while stirring at the same temperature. To do. As the reaction progresses, the reaction system gradually becomes viscous, so the cure time is measured and the reaction proceeds to an appropriate point. This reaction product is dissolved in a solvent such as acetone, methyl ethyl ketone, dioxane, or tetrahydrofuran to mix a predetermined amount of a solution of an acrylic elastomer, and a predetermined amount of a curing accelerator is added to obtain a resin solution having a suitable use as an adhesive. Obtainable. It is also possible to use a solvent from the beginning. For example, in the reaction vessel, N, N'-bisimide compound of unsaturated dicarboxylic acid, aminophenol and aniline or aniline derivative is charged together with dioxane, after proceeding the reaction until a predetermined viscosity while refluxing dioxane, A predetermined amount of epoxy compound is added. Then, the reaction is continued while refluxing dioxane until an appropriate cure time is exhibited, and then a predetermined amount of an acrylic elastomer solution and a predetermined amount of a curing accelerator are mixed to obtain an adhesive composition. The adhesive composition thus prepared may contain various additives and fillers depending on the intended use. Further, if necessary, a filler such as a tackifier or a flame retardant can be appropriately mixed.

(Examples) Next, the present invention will be specifically described with reference to Examples.

Example 1 Maleic acid N, N 'was placed in a flask equipped with a stirrer and a thermometer.
-4,4'-diphenyl ether bisimide 36.03g and p-
Aminophenol 6.0 g, aniline 4.15 g and dioxane 26 g
Was charged, and the reaction proceeded while refluxing dioxane.
The reaction was allowed to proceed for 12 hours until it reached 58 seconds / 50 ° C with a bubble viscometer. The temperature was lowered to 80 ° C., 30 g of Shrimp Coat 828 (trade name, manufactured by Shell Chemical Co., Ltd.) and 52 g of dioxane were added, and heating and stirring were continued for another 30 minutes to cool. To this solution, SG280 (trade name, manufactured by Teikoku Chemical Co., Ltd.) 67 g, 2-ethyl-4methyl-imidazole 0.3 g and a solution of 1.2 g of 4,4'-diaminodiphenyl sulfone dissolved in 5 g of methyl ethyl ketone were added and heat resistance was added. An adhesive composition was produced.

Next, Kapton with a thickness of 25 μm (trade name, manufactured by DuPont)
The above-mentioned adhesive was applied to the so that the thickness after drying was about 35 μm, and dried at 100 ° C. for 5 minutes, and further at 150 ° C. for 2 minutes. Then, a Kapton base copper clad plate (copper foil 35μm) is overlaid on the shine surface of the etched copper foil for evaluation, and using a hot press, press temperature 170 ± 2 ° C, pressure 25kg / cm ² , heating time Lamination was performed for 30 minutes.

Adhesiveness after heat deterioration, solder heat resistance, solder resistance after humidification,
Tests were conducted on the adhesiveness and the insulation resistance between wires after the soldering process, and the results are shown in Table 1. It was possible to confirm the remarkable curing of the present invention.

Example 2 Maleic acid N, N'-4,4'-diphenylmethanebisimide
71.66 g, o-aminophenol (3.28 g) and p-aminobenzoic acid ethyl ester (1.66 g) were charged, and the contents were melted by heating with occasional stirring. Stir this liquid vigorously,
After raising the temperature to 150 ℃ and proceeding the reaction for about 15 minutes, raise the temperature to 120
After the temperature was lowered to 80 ° C., the reaction was further advanced for 15 minutes, and when the temperature was lowered to 80 ° C., 40 g of epoxy resin DEN431 (trade name, manufactured by Dow Chemical Co.) was added, and the mixture was heated and stirred for another hour. Then, it was poured into an enameled vat and cooled, and then pulverized with a mixer. 25% solution of 60 g of crushed resin and acrylic elastomer AR-51 (trade name, manufactured by Nippon Zeon Co., Ltd.) in a mixed solvent of methyl ethyl ketone / toluene = 1/1
30g, AC-4B50 (BF ₃ -imidazole complex, Maruzen Petrochemical Co., Ltd., trade name) 0.2g, and dioxane 170g were respectively weighed and thoroughly stirred with a high-speed stirrer, and heat-resistant by passing through a 100-mesh wire net. An adhesive was prepared.

Next, Kapton with a thickness of 25 μm (trade name, manufactured by DuPont)
The above-mentioned adhesive solution was applied to the above so that the thickness after drying would be about 35 μm, and dried at 100 ° C. for 5 minutes and further at 150 ° C. for 2 minutes. Then, for evaluation, a Kapton base copper clad plate (copper foil 35 μm) was superposed on the shine surface of the etched copper foil using a hot press, and the press temperature was 170 ± 2.
Lamination was performed under the conditions of ℃, pressure 25kg / cm ² , heating time 30 minutes. The adhesiveness after heat deterioration, the soldering heat resistance, the soldering resistance after humidification, the adhesiveness after soldering, and the insulation resistance between wires were tested, and the results are shown in Table 1. The remarkable effect of the present invention was confirmed.

Example 3 Maleic acid N, N'-4,4'-diphenylmethane-bisimide 358 g and 2-amino-4-chlorophenol 72.31 g
And 27.03 g of m-toluidine are mixed, and 100 with stirring.
When it exceeds ℃, it gradually begins to dissolve and becomes a brown liquid.
The liquid was further heated to 120 ° C. and stirred for 1 hour. The thus reacted product was dissolved in dioxane to prepare a 50% solution, and 25 g of an epoxy novolac resin (DEN438, manufactured by Dow Chemical Co., Ltd.) was added to 100 g of the solution (solid content: 50 g). Furthermore, 0.25 g of dimethylbenzyldiamine, SG70L (manufactured by Teikoku Chemical Industry Co., Ltd., trade name, solid content 12.5% MEK / toluene mixed solvent) 133.36 g, and 82 g of dioxane were further weighed and sufficiently stirred with a high-speed stirrer, using a 100 mesh wire mesh. A furnace was passed through to prepare a heat resistant adhesive.

Next, the adhesive solution is applied to the Kapton (mentioned above) having a thickness of 25 μm,
It was applied so that the thickness after drying would be about 22 μm, and dried at 100 ° C. for 5 minutes and further at 150 ° C. for 2 minutes. A 35 μm electrolytic copper foil was overlaid on the adhesive coated surface and laminated using a hot press to a temperature of 170 ± 2 ° C., a pressure of 20 kg / cm ² , and a heating time of 60 minutes to produce a substrate for FPC. . Peel strength of the obtained substrate, adhesion after heat deterioration, solder heat resistance,
The solder resistance after humidification and the insulation resistance between wires were tested, and the results are shown in Table 1. The remarkable effect of the present invention was confirmed.

Comparative Example In Example 3, 2-amino-4-chlorophenol
72.31 g, m-toluidine 27.03 g instead of 2-amino-4-chlorophenol 143.61 g, m-toluicin 108.1
An adhesive and a substrate for FPC were prepared in the same manner as in Example 3 except that g was used, and various tests were conducted in the same manner. The results are shown in Table 1.

[Effects of the Invention] As is clear from the above description and Table 1, the heat-resistant adhesive composition of the present invention has excellent heat resistance, moisture resistance, and adhesiveness,
Further, it has good electrical characteristics, processability, and storage stability, and is suitable as an adhesive for FPC.

Claims (3)

[Claims] 1. (A) Acrylic elastomer having one or more functional groups selected from epoxy group, carboxyl group and hydroxyl group, (B) (a) general formula (In the formula, R ¹ represents a divalent group having at least 2 carbon atoms, and R ² represents a divalent group containing a double bond between carbon atoms.)
An unsaturated dicarboxylic acid N, N′-bisimide compound represented by (Wherein R ³ represents a hydrogen atom, a halogen atom or an alkyl group) and (c) the general formula (Wherein R ⁴ and R ⁵ represent a hydrogen atom, an alkyl group, a halogen atom, a group of —OCH ₃ and —OC ₂ H ₅ and do not contain active hydrogen) and a reaction with an aniline or an aniline derivative. A heat-resistant adhesive composition comprising a product, (C) an epoxy compound having two or more epoxy groups in the molecule, and (D) a curing accelerator as essential components. 2. A resin component [(A) + (B) + comprising an acrylic elastomer, a reaction product and an epoxy compound.
5 to 50% by weight of acrylic elastomer relative to (C)]
The heat-resistant adhesive composition according to claim 1, wherein the heat-resistant adhesive composition is contained in the following ratio. 3. A curing accelerator is added to an epoxy resin in an amount of 0.01
Claims 1 or 2 in an amount of -5% by weight
Item 7. A heat resistant adhesive composition according to any one of items.