JPS63225629A - Polyimide resin - Google Patents

Abstract

PURPOSE:To obtain a polyimide resin excellent in solubility, tensile strength, heat stability, moldability, insulation property, adhesiveness, etc. and suitable as an insulating film or the like, by ring-closing, by heating, a specified polyamic acid having a main chain to which a siloxane structure is introduced. CONSTITUTION:A polyamic acid of the formula (wherein R' is a siloxane, R'' is a bivalent aromatic residue, R''' is a tetravalent aromatic residue, and n is a positive integer) is prepared. This polyamic acid is ring-closed by heating to obtain the purpose polyimide resin. The polyamic acid of the formula is produced by reacting a diamine structure-terminated aromatic diamine compound (e.g., 4,4'-diaminodiphenyl ether) with a diamine structure-terminated siloxane compound [e.g., 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane] and an aromatic tetracarboxylic acid dianhydride (e.g., pyromellitic dianhydride).

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a novel polyimide resin that has excellent thermal cost properties, mechanical properties, adhesive properties, solubility, chemical resistance, and electrical properties. .

[Conventional technology]

Conventionally, an aromatic diamine component such as 4.4'-diaminodiphenyl ether, pyromellitic dianhydride, 3
．． 1 strength and heat resistance by molding and heating a polyamic acid obtained by reacting an aromatic acid dianhydride such as 3',4,4'-benzophenonetetracarboxylic dianhydride in an organic polar solvent. It is known that polyimide molded products with excellent properties can be obtained (Japanese Patent Publication No. 58-8394).
issue).

[Problem that the invention seeks to solve]

However, although such polyimide molded products have excellent tensile strength, their precursor polyamic acids are limited to high boiling point organic polar solvents (N,N-dimethylformamide, N,N-dimethylacetamide).

N-methyl-2-pyrrolidone, dimethyl sulfoxide)
It is insoluble in common low-boiling point solvents (toluene, dioxane, tetrahydrofuran, methyl ethyl ketone, etc.) and has extremely poor workability.

Furthermore, the polyimide obtained by thermally ring-closing the polyamic acid precursor is insoluble in high-boiling organic polar solvents. Further, polyimide has problems in that it has poor adhesion to metals, plastics, etc., and also tends to produce voids and cracks during molding due to the generation of moisture accompanying dehydration and ring closure.

The present invention is intended to solve the above problems.

We aim to improve the solubility, moldability, and adhesiveness, which are the shortcomings of conventional polyimides, and to obtain polyimide resins with excellent thermal stability, mechanical properties, adhesiveness, solubility, chemical resistance, and electrical properties. The purpose is

[Means for solving problems]

As a result of extensive research into polyimide resins, the present inventors have found that by introducing a siloxane structure into the main face of a polyamic acid compound, which is a precursor of polyimide resins, we have achieved thermal stability equivalent to that of conventional polyimide molded products. have sex,
Furthermore, they discovered that mechanical and electrical properties, solubility, adhesion to other substances, etc. could be highly improved, and this invention was completed.

That is, the present invention is based on the general formula (wherein R' is a siloxane group, R' is a divalent aromatic residue, R1 is a tetravalent aromatic residue, and n is this integer.

) is a novel polyimide resin made by thermally ring-closing a polyamic acid represented by

The precursor of the polyimide resin of the present invention has the above general formula (1
) is a polyamic acid represented by This polyamic acid is an aromatic diamine compound H,NR'-NH,...(2) (where R' in formula 1 is a divalent aromatic residue) having a terminal diamine structure represented by the following formula. ) and a siloxane compound 1 having a terminal diamine structure represented by the following formula (dJ-(cHJsR')CHshNH*
” (3) (However, R' in formula 1 is a siloxane group.)
and one or more aromatic tetracarboxylic dianhydrides represented by the following formula (in formula 1, R' is a tetravalent aromatic residue) in a molar ratio of 1:1=2, and polar Obtained by reaction in a solvent.

The polyamic acid thus obtained undergoes dehydration and ring closure through heat treatment and is converted into polyimide resin. In this case, the heat treatment temperature is 160°C or higher, preferably 200°C to
00°C is sufficient.

Examples of the aromatic diamine compound having the terminal diamine structure of formula (2) used in the present invention include 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, and 4,4'-diaminodiphenyl sulfone. .

In addition, as a siloxane compound having a terminal diamine structure of formula (3), 1,3-bis(3-7minoprobyl)-1
, 1,3,3-tetramethyldisiloxane, 1,5-bis(3-aminopropyl)-1,1,3,3,5,5-
Hexamethyltrisiloxane, 1. Two-bis(3-aminopropyl)-1゜1.3,3,5,5,7,7-octamethyltetrasiloxane, etc. with 2 to 5 siloxane groups
There are siloxane compounds.

As the aromatic tetracarboxylic dianhydride of formula (4),
3.3', 4.4'-benzophenonetetracarboxylic dianhydride, pyromellitic dianhydride, 3.3', 4
Examples include 4'-biphenyltetracarboxylic dianhydride. As the reaction solvent used in the above reaction, inert solvents such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide are used. Depending on the purpose of use, toluene or the like may be used in combination with the above solvent.

[For production]

In the polyimide resin of the present invention, since a siloxane structure is introduced into the main chain of the polyamic acid precursor,
Thermal stability possessed by conventional polyimide resins 1 The solubility, moldability, and adhesion of its precursor and resin are improved without compromising mechanical strength, making it suitable for use as a heat-resistant resin in semiconductor multilayer wiring interlayer insulating films, and insulation. It can be used in a wide range of applications, including films, heat-resistant films, and molding materials.

〔Example〕

The present invention will be specifically described below with reference to Examples.

Example 1 A 500-seater equipped with a thermometer and a stirrer in a nitrogen atmosphere
Pyromellitic dianhydride 17.45 in a four-bottle flask
The concentration is also 15% in the following example, in which 0.08 mol) is dissolved in N,N-dimethylacetamide 236@Q and stirred.

After keeping the reaction system at 10°C, 9.94 g (0.04 mol) of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and further 4,4'- 8.01 g (0.04 mol) of diaminodiphenyl ether and two types of terminal diamine compounds were added dropwise over about 2 minutes. The reaction was carried out at 10° C. for 2 hours and then at room temperature for 5 hours with vigorous stirring.

A polyamic acid solution which is a precursor of the polyimide resin of the present invention was obtained.

Examples 2 to 18 A polyamic acid solution was obtained under the same reaction conditions as in Example 1, except that the combinations of various siloxane compounds, aromatic diamine compounds, and aromatic tetracarboxylic dianhydrides shown in Table 1 were used. .

Table 1 Note) BAPTMS: 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane BAPOMS: 1,7-bis(3-7minoprovir)-1,1,3, 3,5,5゜7.7-octamethyltetrasiloxane ODE: 4,4'-diaminodiphenyl ether DDM: 4.4'-diaminodiphenylmethane DO5=4.4'-diaminodiphenylsulfone PMOA: pyromellitic dianhydride BTD
A: 3,3',4,4'-benzophenonetetracarboxylic dianhydride BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride Polyamic acid solution synthesized in Examples 1 to 18 above After spin-casting several times on a glass plate, heat treatment was performed in nitrogen at 200°C for 2 hours and then at 280°C for 3 hours, resulting in a film thickness of 12
A polyimide film of ~18 μm was obtained, and the film forming ability was satisfactory in all Examples 1 to 18 above.

Table 2 shows the glass transition temperature and thermal stability of each of the polyimide films obtained from the polyamic acid solutions of Examples 1 to 18, and Table 3 shows the tensile strength and heat shrinkage rate of the polyimide films.

Table 4 shows the linear expansion coefficient and dielectric breakdown voltage of the polyamic acids of Examples 1 to 18, and Table 5 shows the solubility of the polyimide resins obtained from them in various solvents.

Table 2 Table 2 (continued) ・：5% weight dehumidification temperature (heating rate 10℃/min.

(in nitrogen atmosphere) Table 3 Table 4 Note) O: soluble, ∆ partially dissolved, ×: insoluble DMAc:
N,N-dimethylacetamide DNF: N,N-dimethylformamide NNP: N-methyl-2-pyrrolidone THF: Tetrahydrofuran Table 5 Note) o: Soluble, ∆ partially dissolved, ×: Insoluble DMAc:
N,N-dimethylacetamide DMF: N,N-dimethylformamide NMP: N-methyl-2-pyrrolidone THF: Tetrahydrofuran Next, the polyamic acid solutions synthesized in Examples 1 to 18 were cast several times on an aluminum plate. in nitrogen.

Heat treatment was performed at 200° C. for 2 hours and then at 280° C. for 3 hours, and the adhesive strength with the aluminum plate was evaluated by a substrate test (JIS K-5400). The results are shown in Table 6.

Table 6 Table 6 (Continued) (Showing the evaluation scores according to the basic test of JIS K-5400) Comparative example Pyromellitic dianhydride (0.08 mol) as aromatic tetracarboxylic dianhydride, and diamine compound The results using polyamic acid reacted with 4,4'-diaminodiphenyl ether (0.08 mol), which is an aromatic diamine, are also shown in Tables 2 to 6.

〔Effect of the invention〕

According to the present invention, since the main chain of polyimide has a siloxane structure, the solubility of polyamic acid, which is a precursor of polyimide resin, is improved, and the polyimide resin produced by heat treatment of this polyamic acid has a high solubility. Tensile strength, heat shrinkability.

Mechanical, electrical, and thermal properties such as insulation and adhesion with other substances are dramatically improved, making it useful for a wide range of applications.

Claims (2)

[Claims] (1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼... (1) (However, in the formula, R' is a siloxane group, R'' is a divalent aromatic residue, and R''' is a tetravalent aromatic residue. Aromatic residue, n is a positive integer.) A polyimide resin obtained by thermally ring-closing a polyamic acid represented by: (2) The polyimide according to claim 1, wherein the polyamic acid is a reaction product of an aromatic diamine compound having a terminal diamine structure, a siloxane compound having a terminal diamine structure, and an aromatic tetracarboxylic dianhydride. system resin.