JPH0253829A - Production of aromatic polymide resin - Google Patents

Abstract

PURPOSE:To obtain the title resin having excellent moldability, heat resistance and mechanical and thermal characteristics and useful for a composite material, etc., by blending and compatibilizing different and plural polyamic acids and then imidizing the polyamic acids using a chemical cyclizing agent. CONSTITUTION:(A) A polymer acid obtained by reacting p-phenylene diamine with pyromellitic dianhydrides is blended and compatibilized with (B) a polyamic acid obtained by reacting an aromatic diamine with an aromatic tetracarboxylic acid dianhydrides and then the blend is imidized using a chemical cyclizing agent (e.g., acetic anhydride) to provide the aimed resin. Furthermore, the cyclization treatment is preferably carried out by reacting the above-mentioned blend at 10-50 deg.C for >=12hr and subjecting the blend to vacuum drying at 50-200 deg.C for >=1hr.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a method for producing an aromatic polyimide resin that is solution castable and exhibits excellent moldability as well as excellent heat resistance, mechanical properties, and thermal properties. It is related to.

[Conventional technology]

Polymer materials are used in the field of membrane materials, such as alumina substrates, insulating materials for printed circuits formed on metal plates, base materials for flexible printed circuits, and glabella insulating films for multilayer wiring of LSIs, as well as composite materials. It has been used in the field of structural materials such as matrix resins due to its excellent electrical insulation and processability. In these fields, improvements in heat resistance have traditionally been considered in order to improve performance, but in recent years, improvements in dimensional stability and heat resistance when used in combination with other materials, such as ceramics, have been considered from the perspective of reliability as parts. In order to prevent expansion coefficient mismatches, excellent mechanical and thermal properties such as high rigidity and thermal expansion coefficient are also required.

Aromatic polyimides have been well known as polymeric materials with excellent heat resistance. Because this polyimide has a soluble precursor, it is often used as a solution-castable coating or membrane material, but its mechanical properties are generally on the same level as ordinary polymer materials, and its coefficient of thermal expansion is large. It also did not have excellent thermal properties. On the other hand, although polyimide obtained by polycondensation of P-phenylenediamine and pyromellitic dianhydride and heat curing is expected to have high rigidity due to its molecular structure,
The resulting membrane was brittle and impractical.

[Problem to be solved by the invention]

The present invention specifically solves the above-mentioned drawbacks of aromatic polyimides containing p-phenylene pyromellitimide. Cyclization (US
The object of the present invention is to provide a method for producing an aromatic polyimide resin that can be used as a tough film or coating film with excellent mechanical properties and thermal properties.

[Means to solve the problem]

The present invention involves mixing and dissolving a polyamic acid obtained by reacting p-phenylene diamine and pyromellitic dianhydride with a polyamic acid obtained by reacting an aromatic diamine with an aromatic tetracarboxylic dianhydride. This is a method for producing an aromatic polyimide resin, which is characterized in that the aromatic polyimide resin is then imidized using a chemical cyclizing agent.

Examples of the aromatic diamine used in the present invention include 2N 4\-1 -NH2. These aromatic diamines can be used alone or in combination of two or more.

Further, examples of the aromatic tetracarboxylic dianhydride include the following, and it is also possible to use it alone or in a mixture of two or more kinds. However, in view of the gist of the present invention, aromatic diamine and aromatic tetracarboxylic dianhydride are simultaneously p
- Must not be phenylene diamine and pyromellitic dianhydride.

The weight ratio of the polyamic acid obtained from P-phenylene diamine and pyromellitic dianhydride to the polyamic acid obtained from aromatic diamine and aromatic tetracarboxylic dianhydride is 10:90 to 95:5. desirable. This is because if the total amount of p-phenylenediamine and pyromellitic acid derivative is less than 10% by weight, it tends not to exhibit good mechanical and thermal properties, and if it exceeds 95% by weight, it tends to become brittle. .

Although any commonly used polycondensation method can be applied to the method for synthesizing polyamic acid in the present invention, low-temperature solution polycondensation is particularly preferred. That is, by dissolving the above-mentioned p-phenylene diamine and pyromellitic dianhydride, and aromatic diamine and aromatic tetracarboxylic dianhydride, respectively, and polycondensing them at a low temperature of 0 to 10°C, a high molecular weight aromatic polyamic acid is obtained. Acid is obtained. By mixing this solution in the above ratio, casting it on a substrate, and concentrating the solvent, a film of mixed and compatible polyamic acid can be obtained.

The solvent during the above reaction and casting is as follows:
The aromatic compound produced by dissolving the reaction reagent containing the above-mentioned P-phenylene diamine, pyromellitic dianhydride, aromatic diamine, and aromatic tetracarboxylic dianhydride and essentially not reacting with it. It is desirable that the polyamic acid be dissolved or stably dispersed. Examples of such a solvent include N-methylpyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphoric triamide, and mixed solvents thereof can also be used.

The thus obtained mixed and compatible polyamic acid film is peeled off from the substrate, fixed on an iron frame, and then immersed in a chemical cyclizing agent for imidization. As the cyclizing agent used here, aliphatic acid anhydrides such as acetic anhydride and propionic anhydride are suitable, and acetic anhydride is particularly preferred. Further, in this chemical cyclization, an organic base such as pyridine, 3-methylpyridine, 3,5-lutidine, or quinoline can be used as a catalyst, and it is preferable to use the above-mentioned acetic anhydride and pyridine in combination. Other organic solvents may be used as diluents during this chemical cyclization.

Diluents include dioxane, tetrahydrofuran, benzene, chloroform, carbon tetrachloride, acetonitrile,
Examples include ethyl acetate. The chemical cyclization treatment conditions are a temperature of 10 to 50°C and a treatment time of 10 minutes to 24 hours, preferably 12 hours or more.

Thereafter, the aromatic polyimide resin of the present invention is obtained by vacuum drying at 50 to 200°C for 1 hour or more.

In the present invention, the aromatic polyamic acid solution after the polycondensation reaction may be mixed as it is to form a film.
It is also possible to use a solution in which the polycondensation reaction solution is poured into a large amount of methanol, etc., the polyamic acid is precipitated and purified, and then mixed and redissolved in the solvent. The mixed polyamic acid solution is cast onto the substrate using a spinner or coater,
After that, it is desirable to concentrate the solvent by heating or vacuum drying so that the polymer concentration becomes 40 to 70%. This is because if the polymer concentration is less than 40%, it tends to become cloudy when immersed in the cyclizing agent.

The mixed and compatible aromatic polyamic acid in the present invention is
Highly rigid and tough films, coatings, etc. can be obtained by casting, concentrating, forming a film, and then immersing it in a chemical cyclizing agent using a solution such as that described in 2. It is possible to carry out a stretching treatment before immersion in the chemical cyclizing agent. It is also possible to use it in combination with various filler 1 reinforcing agents to form a composite material.

〔Example〕

The present invention will be explained below with reference to Examples.

Example 1 p-phenylenediamine 9.733g (0.09mol)
Pour 500 ml (l) of N-methylpyrrolidone into a four-eye flask equipped with a stirrer, nitrogen gas inlet tube, and thermometer.
After dissolving, add pyromellitic dianhydride 19.631 under water cooling.
g (0.09 mol) was added thereto, and the polycondensation reaction was carried out with stirring at 0 to 10°C for 1 hour and then at room temperature for 4 hours. Similarly, 2.002 g (0.01 mol) of diaminodiphenyl ether and 2.181 g (0.01 mol) of pyromellitic dianhydride
mol) was subjected to a polycondensation reaction in 50 mfl of N-methylpyrrolidone.

Then, the above two types of amic acid solutions were mixed at room temperature,
The mixture was stirred for about 2 hours to obtain a uniform mixed polyamic acid solution.

Next, the mixed solution mentioned above was applied to a glass plate, air-dried at 80'C for 2 hours, then removed from the glass plate and fixed on an iron frame.
, benzene 1.80m+Q for 12 hours or more. This was vacuum dried at 180° C. for 2 hours to obtain a polyimide film. This film is 1.780cm"
Infrared absorption due to imide groups was observed near "-", confirming imidization.The glass transition temperature of this film was 40
0° C. or higher (DSC method), and various characteristics are as shown in Table 1.

Example 2 According to Example 1, p-phenylenediamine 5.407
g (0.05 mol) and pyromellitic dianhydride 10.9
0.06 g (0.05 mol), diaminodiphenyl ether], 0.012 g (0.05 mol) and 1.0.906 g (0.05 mol) of pyromellitic dianhydride were each polycondensed in 300 mQ of N-methylpyrrolidone. react,
A mixed polyamic acid solution was obtained.

The mixed polyamic acid solution obtained above was chemically cyclized according to Example 1 to obtain a polyimide film. Various properties of this film are shown in Table 1.

Example 3 9.733 g of p-phenylenediamine according to Example 1
(0.09 mol) and pyromellitic dianhydride 19.63
1 g (0.09 mol), diaminodiphenyl ether 2
．． 002g (0.01 mol) and benzophenonetetracarboxylic dianhydride (0.01 mol) were each subjected to a polycondensation reaction in 300 mQ of N-methylpyrrolidone to obtain a mixed polyamic acid solution.

The mixed polyamic acid solution obtained above was chemically cyclized according to Example 1 to obtain a polyimide film. Various properties of this film are shown in Table 1.

Comparative Example 1 According to Example 1, p-phenylenediamine 9.733
g (0.09 mol) and pyromellitic acid 19.631 g (
0.09 mol), diaminodiphenyl ether 2.00
2g (0.01 mol) and pyromellitic dianhydride 2.1
81 g (0.01 mol) of each were subjected to a polycondensation reaction in N-methylpyrrolidone to obtain a mixed polyamic acid solution.

The mixed polyamic acid solution obtained above was applied onto a glass plate, air-dried in an oven at 80°C for 2 hours, removed from the glass plate, fixed on an iron frame, and then heated at 200°C for 1 hour.
The polyimide film was cured by heating at 300° C. for 1 hour. However, the resulting film was so fragile that it was impossible to measure its various properties.

Claims (1)

[Claims] (1) Polyamic acid obtained by reacting p-phenylene diamine and pyromellitic dianhydride and polyamic acid obtained by reacting aromatic diamine and aromatic tetracarboxylic dianhydride were mixed and made compatible. A method for producing an aromatic polyimide resin, which is then imidized using a chemical cyclizing agent.