JP2603928B2 - Novel polyamic acid composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel polyamic acid composition which is a precursor of a polyimide resin known as a heat-resistant resin. Specifically, the present invention relates to a novel polyamic acid composition used as a precursor for producing a polyimide resin having excellent thermal dimensional stability and excellent mechanical properties.

(Prior art) Conventionally, polyimide resins are known to have high heat resistance, chemical resistance, electrical properties, mechanical properties, and other excellent properties. A polyimide film obtained by using a polyamic acid composed of 4,4'-diaminodiphenyl ether and pyromellitic dianhydride as shown in 10999 has been widely used in the past, and has been used for various mechanical properties such as elongation. It is known that although it has excellent characteristics, it generally has a large coefficient of linear expansion and poor thermal dimensional stability. On the other hand, a polyimide film obtained by using a polyamic acid composed of paraphenylenediamine and pyromellitic dianhydride has a small linear expansion coefficient and excellent thermal dimensional stability, but is very fragile, and is practically used as a film. However, it has a disadvantage that it cannot be used industrially in practice.

On the other hand, in recent years, there has been an increasing demand for a polyimide resin having more excellent thermal dimensional stability and excellent mechanical properties such as elongation, and various studies have been made for this purpose. . For example, JP-A-61-264028,
61-241325, JP-A-61-181828, JP-A-61-158025, JP-A-58-185624, etc., for the purpose of improving thermal dimensional stability, for example, paraphenylenediamine, dimethylbenzidine and pyromellitic dianhydride. For the purpose of improving rigidity and other mechanical properties by using rigid molecules such as
A soft segment such as diaminodiphenyl ether, benzophenonetetracarboxylic dianhydride or biphenyltetracarboxylic dianhydride is used, and all of them are intended to achieve the above object by utilizing a polyamic acid obtained by copolymerization of these soft segments.

However, in the improved method using the above copolymerization method,
For example, a polyimide resin using a polyamic acid such as dimethylbenzidine or benzophenonetetracarboxylic dianhydride has insufficient heat resistance, and a polyimide resin using a polyamic acid such as biphenyltetracarboxylic dianhydride has a tensile strength. There is a problem that a yield point is generated in the test and stress strain occurs.

Further, according to such a copolymerization method, the arrangement of the monomer units in one molecule becomes irregular, and it is extremely difficult to control this. As a result, the resulting polyimide resin has a disadvantage that the performance becomes unstable.

(Problems to be Solved by the Invention) Conventionally widely used polyimide resins have a large linear expansion coefficient of about 3 × 10 ⁻⁵ ° C. ^−1, and have poor thermal dimensional stability.
When laminated with a metal or the like, there is a problem that a so-called warpage or curl occurs.

On the other hand, various attempts have been made to make the linear expansion coefficient close to that of metal, but the polyimide film obtained in any case causes problems in mechanical strength, heat resistance, and chemical resistance, and furthermore, polyamic acid In the polymerization, the molecular structure could not be regulated, and the performance of the obtained polyimide resin was extremely unstable.

(Means for Solving the Problems) In order to solve the above problems, the present inventors have conducted intensive studies, and as a result, the polymerization was carried out using substantially equimolar amounts of pyromellitic dianhydride and 4,4'-diaminodiphenyl ether. General formula [Wherein, m is a positive integer] a polyamic acid solution in which a polyamic acid (A) composed of a repeating unit represented by the following formula is dissolved in an organic polar solvent in an amount of 5 to 40% by weight, and mainly pyromellitic dianhydride And a general formula obtained by polymerization using substantially equimolar amounts of paraphenylenediamine and [Wherein, n is a positive integer] a polyamic acid solution in which 5 to 40% by weight of a polyamic acid (B) composed of a repeating unit represented by the following formula (1) is dissolved in an organic polar solvent: A: B is 8 from 20:80
A polyamic acid composition characterized by a ratio of up to 0:20 has been found. The polyimide resin obtained from this polyamic acid composition has a small coefficient of linear expansion and excellent mechanical strength.

The structure of the polyamic acid composition will be described in detail. The polyamic acid (A) and the polyamic acid (B) are (A) :( B) in a molar ratio of the repeating unit in a ratio of 20:80 to 80:20. It is desirable to mix at a ratio of preferably 30:70 to 80:20. Polyamic acid (A) in molar ratio of 80
% Or more, but the resulting polyamide film has a small effect of improving the thermal dimensional stability. On the other hand, it is also possible to mix the polyamic acid (B) at a molar ratio of 80% or more. Although possible, the resulting polyimide film is fragile and does not substantially form a film. The number of repetitions of the polyamic acids (A) and (B),
The sizes of m and n are not restricted at all. However, when a large mechanical strength of the polyimide is required, the weighted average value of the weight average molecular weight of the polyamic acid (A) and the polyamic acid (B) in consideration of the mixed weight of the polymers (A) and (B) is given by It is preferably 20,000 or more, more preferably 100,000 or more. Although the polyamic acid composition can be taken out in a solid form, it is contained in an organic polar solvent in an amount of 5 to 40% by weight, preferably 5 to 30% by weight.
% By weight, more preferably 5 to 25% by weight, from the viewpoint of handling.

Next, a method for producing the polyamic acid composition will be described. Pyromellitic dianhydride is used as an aromatic tetracarboxylic dianhydride, and 4,4'-diaminodiphenyl ether is used as an aromatic diamine component. The components are used in substantially equimolar amounts, and 0 to 0 in an organic polar solvent.
100 ° C, preferably 8 to 80 ° C, more preferably 5 to 50 ° C
To obtain the polyamic acid (A). On the other hand, in the same manner, using pyromellitic dianhydride as an aromatic tetracarboxylic dianhydride, using paraphenylenediamine as an aromatic diamine component, using these equimolar amounts of these two components, and using an organic polar solvent. At a temperature of 0 to 100 ° C, preferably 5 to 80 ° C, more preferably 5 to 50 ° C to obtain the polyamic acid (B).

However, when obtaining the polyamic acid (A) or the polyamic acid (B), it is most desirable to use pyromellitic dianhydride alone as the aromatic tetracarboxylic dianhydride in order to obtain the effects of the present invention. , For example, 3,3 ', 4,4'-
Diphenyltetracarboxylic dianhydride, 3,3 ', 4,4'-
It is also possible to use tetrabasic anhydrides such as benzophenonetetracarboxylic dianhydride and naphthalene-1,2,5,6-dianhydride. An acid anhydride other than pyromellitic dianhydride can be used in any amount as long as the objects and effects of the present invention are achieved. However, the amount of the acid anhydride is not more than 10% based on the total acid anhydride component in the polymer (A) or (B). It is suitable that the amount is not more than 5 mol%, preferably not more than 5 mol%, and more preferably not more than 3%. In addition, when obtaining the polyamic acid (A), it is most preferable to use 4,4-diaminodiphenyl ether alone as the diamine component, and when obtaining the polyamic acid (B), use paraphenylenediamine alone as the diamine component. It is most preferable to obtain either polyamic acid (A) or polyamic acid (B) by the general formula: H ₂ N—R—NH ₂ (where R is a divalent organic group). Diamine compounds such as 4,4'-bis (4
-Aminophenoxy) biphenyl, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] Sulfone, bis [4- (2-aminophenoxy) phenyl] sulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3- Aminophenoxy) benzene, 1,4-bis (4-aminophenyl) benzene, bis [4- (4-aminophenoxy) phenyl] ether,
4,4'-diaminodiphenylmethane, bis (3-ethyl-4-aminophenyl) methane, bis (3-methyl-4
-Aminophenyl) methane, bis (3-chloro-4-aminophenyl) methane, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3'-
Dimethoxy-4,4'-diaminodiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dichloro-
4,4'-diaminobiphenyl, 2,2 ', 5,5'-tetrachloro-4,4'-diaminobiphenyl, 3,3'-dicarboxy-4,4'-diaminobiphenyl, 3,3'- Dihydroxy-
4,4'-diaminobiphenyl, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide,
3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'-diaminobiphenyl, 4,4'-diaminooctafluorobiphenyl, 2,4-diaminotoluene, para Phenylenediamine, metal phenylenediamine, 2,2
-Bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2-bis (4-aminophenyl) propane, 2, 2-bis (4-aminophenyl) hexafluoropropane, 2,2-bis (3-hydroxy-4-aminophenyl) propane, 2,2-bis (3
-Hydroxy-4-aminophenyl) hexafluoropropane, 9,9-bis (4-aminophenyl) -10-hydro-anthracene, orthotrizine sulfone and 3,3 ', 4,
Partial use of tetramines such as 4'-biphenyltetraamine and 3,3 ', 4,4'-tetraaminodiphenyl ether is also possible. Polyhydric amines other than 4,4'-diaminodiphenyl ether and paraphenylenediamine can be used in any amount as long as the objects and effects of the present invention are achieved. It is suitable to use 10 mol% or less, preferably 5 mol% or less, more preferably 3 mol% or less.

Examples of the organic polar solvent used for the production reaction of the polyamic acid (A) and the polyamic acid (B) include, for example, sulfoxide-based solvents such as dimethyl sulfoxide and diethyl sulfoxide, N, N-dimethylformamide, and N, N-diethylformamide. Formamide-based solvents such as N, N-dimethylacetamide, N, N-N-diethylacetamide and other acetamido-based solvents, N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone and other pyrrolidone-based solvents, phenol, o- , M- or p-cresol, xylenol, halogenated phenol, phenolic solvents such as catechol, or hexamethylphosphoramide, γ-butyrolactone, and the like, and these are preferably used alone or as a mixture. Furthermore, xylene,
Partial use of aromatic hydrocarbons such as toluene is also possible. Polyamic acid (A) and polyamic acid (B)
Is preferably 5 to 40% by weight, preferably 5 to 30% by weight, more preferably 5 to 25% by weight in the above-mentioned organic polar solvent from the viewpoint of handling.

A polyamic acid solution in which the polyamic acid (A) is dissolved in an organic polar solvent and a polyamic acid solution in which the polyamic acid (B) is dissolved in an organic polar solvent are represented by (A):
(B) can be mixed at a repeating unit molar ratio of 20:80 to 80:20, preferably at a ratio of 30:70 to 80:20 to obtain a solution of the polyamic acid composition of the present invention. it can. The method of mixing the polyamic acid solution is not particularly limited. The composition can be dried at a temperature of 60 ° C. or lower to obtain a solid composition.

The polyamic acid mixed solution thus obtained is cast or coated to form a film, and the film is dried and the polyamide acid is thermally or chemically dehydrated and ring-closed (imidized) to form a polyimide film. be able to.

The polyimide film obtained from the polyamic acid composition of the present invention has extremely excellent thermal dimensional stability, excellent mechanical properties such as elongation, and, unlike conventional copolymers, has predetermined properties. Obtained stably.

(Examples) Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to only these examples.

Comparative Examples 1-3 In a 500 ml four-necked flask, 21.54 g of 4,4'-diaminodiphenyl ether was collected, and 845.00 g, 245.00 g, and 95.0 g, respectively.
0 g of N, N-dimethylacetamide was added and dissolved. On the other hand, in a 100 ml eggplant flask, pyromellitic dianhydride 23.46
g was collected and added as a solid to the 4,4'-diaminodiphenyl ether solution. Furthermore, pyromellitic dianhydride remaining on the wall surface of the 100 ml eggplant flask is removed.
10.00 g of N, N-dimethylacetamide was poured into the reaction system (four-neck flask). Stirring was further continued for 1 hour to obtain polyamic acid solutions of 5, 15, and 30% by weight, respectively. The reaction temperature was kept at 5-10 ° C. However, with the above operation, the handling of pyromellitic dianhydride and the inside of the reaction system were placed under a stream of dry nitrogen.

Next, these polyamic acid solutions were cast-coated on a glass plate and dried at about 100 ° C. for about 60 minutes.Then, the polyamic acid coating film was peeled off from the glass plate, and the coating film was fixed on a support frame. About 30 minutes at about 200 ° C, about 60 minutes at about 200 ° C, about 6 minutes at about 300 ° C
After heating for 0 minutes and dehydration ring closure drying, a polyimide film of 15 to 25 microns was obtained. These films exhibited the following properties:

Linear expansion coefficient (at 200 ° C.) 3.5 × 10 ⁻⁵ (cm / cm / ° C.) Elongation 85.7% Comparative example 4-6 Paraphenylenediamine 14.91 in a 500 ml four-necked flask
g, 845.00 g, 245.00 g, and 95.09 g of N, N-dimethylacetamide were added and dissolved, and 30.00 g of pyromellitic dianhydride was reacted according to the methods of Comparative Examples 1 to 3 to obtain 5, 15 g, respectively. And a 30% by weight polyamic acid solution. However,
Pyromellitic dianhydride remaining on the final wall is 1
The solution was poured into the reaction system (four-necked flask) with 0.00 g of N, N-dimethylacetamide.

Next, polyimide films were obtained from these polyamic acid solutions according to the methods of Comparative Examples 1 to 3, but these films were brittle and their properties could not be measured.

Example 1 In a 500 ml four-necked flask, 158.72 g of a 15% by weight polyamic acid solution obtained according to the method of Comparative Example 2 was collected, and 41.28 g of a 15% by weight polyamic acid solution obtained according to the method of Comparative Example 5 were mixed. About 10 at 5-10 ° C under dry nitrogen stream
Stirred for minutes. Next, according to the method of Comparative Example 1,
A polyimide film was obtained from the mixed solution of polyamic acid by weight.
This film exhibited the following properties:

Coefficient of linear expansion (at 200 ° C.) 1.72 × 10 ⁻⁵ (cm / cm / ° C.) Elongation 32.8% Example 2 112.35 g of a 15% by weight polyamic acid solution obtained according to the method of Comparative Example 2 in a 500 ml four-necked flask The mixture was further mixed with 87.65 g of a 15% by weight polyamic acid solution obtained according to the method of Comparative Example 5, and dried at 5 to 10 ° C. under a dry nitrogen stream at about 10 ° C.
Stirred for minutes. Next, a polyimide film was obtained from this 15% by weight polyamic acid mixed solution according to the methods of Comparative Examples 1 to 3. This film exhibited the following properties:

Coefficient of linear expansion (at 200 ° C.) 0.69 × 10 ⁻⁵ (cm / cm / ° C.) Elongation 14.7% Example 3 176.98 g of a 5% by weight polyamic acid solution obtained according to the method of Comparative Example 1 in a 500 ml four-necked flask The mixture was further mixed with 23.02 g of a 30% by weight polyamic acid solution obtained according to the method of Comparative Example 6 and dried at 5 to 10 ° C. under a dry nitrogen stream at about 10 ° C.
Stirred for minutes. Next, a polyimide film was obtained from this polyamic acid mixed solution according to the methods of Comparative Examples 1 to 3. This film exhibited the following properties:

Linear expansion coefficient (at 200 ° C.) 0.69 × 10 ⁻⁵ (cm / cm / ° C.) Elongation 14.7% Example 4 35.21 g of a 30% by weight polyamic acid solution obtained according to the method of Comparative Example 3 in a 500 ml four-necked flask 164.79 g of a 5% by weight polyamic acid solution obtained according to the method of Comparative Example 4 were mixed, and dried at 5 to 10 ° C. under a dry nitrogen stream at about 10 ° C.
Stirred for minutes. Next, a polyimide film was obtained from this polyamic acid mixed solution according to the methods of Comparative Examples 1 to 3. This film exhibited the following properties:

Coefficient of linear expansion (at 200 ° C.) 0.69 × 10 ⁻⁵ (cm / cm / ° C.) Elongation 14.7% Example 5 59.87 g of a 15% by weight polyamic acid solution obtained according to the method of Comparative Example 1 in a 500 ml four-necked flask And further mixed with 140.13 g of a 15% by weight polyamic acid solution obtained according to the method of Comparative Example 2 and dried at 5 to 10 ° C. under a dry nitrogen stream at about 10 ° C.
Stirred for minutes. Next, a polyimide film was obtained from this 15% by weight polyamic acid mixed solution according to the methods of Comparative Examples 1 to 3. This film exhibited the following properties:

Linear expansion coefficient (at 200 ° C.) 0.23 × 10 ⁻⁵ (cm / cm / ° C.) Elongation 5.0% The results of Comparative Examples 1 to 3 and Examples 1 to 5 are summarized in Table 1. (Effects of the Invention) The polyimide film obtained from the polyamic acid composition of the present invention has a smaller linear expansion coefficient than the known polyimide film, is excellent in thermal dimensional stability, and is further improved by reducing the known linear expansion coefficient. This has the effect of having the flexibility, heat resistance, and processability that the polyimide film could not have.

In particular, by controlling the structure of the repeating unit in one molecule of the polyamic acid, which cannot be achieved by the conventional copolymerization method, the performance of the resulting polyimide film can be made constant.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hirosaku Nagano 2-9-130 Maikodai, Tarumizu-ku, Kobe-shi, Hyogo Prefecture (56) References -161831 (JP, A)

Claims (1)

(57) [Claims] (1) pyromellitic dianhydride and 4,4 '
-General formula obtained by polymerization using substantially equimolar amounts of diaminodiphenyl ether [Wherein, m is a positive integer] a polyamic acid solution in which a polyamic acid (A) composed of a repeating unit represented by the following formula is dissolved in an organic polar solvent in an amount of 5 to 40% by weight, and mainly pyromellitic dianhydride And a general formula obtained by polymerization using substantially equimolar amounts of paraphenylenediamine and [Wherein, n is a positive integer] a polyamic acid solution in which 5 to 40% by weight of a polyamic acid (B) composed of a repeating unit represented by the following formula (1) is dissolved in an organic polar solvent: A: B is 8 from 20:80
A polyamic acid composition having a ratio of up to 0:20.