JP2831867B2 - Polyamic acid copolymer, polyimide copolymer comprising the same, polyimide film, and methods for producing them - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamic acid copolymer which gives a polyimide film having excellent heat resistance, high elasticity, low thermal expansion and low moisture absorption, a polyimide copolymer comprising the same, a polyimide film and a polyimide film thereof. It relates to a manufacturing method.

[0002]

2. Description of the Related Art Hitherto, a polyimide resin has excellent electrical insulation as well as excellent heat resistance, and is widely used as an industrial material including electric equipment. Polyimide resin is
In this way, it has various superior properties compared to other polymers, but with the advancement of technology, the required properties required for polyimide resin also become advanced, and it is desired to have various performances depending on the application. I have.

[0003] When it is considered to be used for electric equipment, if the hygroscopicity is high, the electrical insulation is reduced, and the risk of contamination with ionic impurities is increased, and the reliability as a material is undesirably reduced. Therefore, low moisture absorption is desired. Further, from the viewpoint of strength as a material, it is desirable that the material has high elasticity. Since it is preferable that the dimensional change is small with respect to the temperature change, low thermal expansion is required.

[0004] For example, if only a rigid straight chain such as pyromellitic anhydride and paraphenylenediamine is used, a polyimide having high elasticity can be synthesized. But,
With this structure, only films that are very brittle and have high hygroscopicity can be obtained. In addition, polyimide is generally a resin having relatively high water absorption due to large polarization of a carbonyl group and a nitrogen atom in an imide ring. Thus, there is a need for a polyimide that sufficiently satisfies the physical properties of high elasticity, low moisture absorption, and appropriate flexibility.

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to a polyamic acid copolymer which is excellent in heat resistance and gives excellent properties such as high elasticity, low coefficient of thermal expansion and low moisture absorption, a polyimide copolymer and a polyimide film comprising the same. It is another object of the present invention to provide a method for producing them.

[0006]

Means for Solving the Problems In order to solve the above problems, the present inventors have made intensive studies and completed the present invention. That is, the first aspect of the present invention is as follows:

[0007]

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(Where R ₂ and R ₄ are the following groups)

[0009]

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(Where X is F, Cl, Br, CH ₃ ,
CH ₃ O and CF ₃ are shown. A) a linear diamine (hereinafter, referred to as a linear diamine) residue having a structure in which the main chain direction of the diamine does not include a straight line connecting two nitrogen atoms and does not include a bending group such as an ether bond selected from the above. And R ₆ are the following groups

[0011]

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A flexible diamine (hereinafter, referred to as a flexible diamine) residue having a structure containing a bending group such as an ether bond or a carbonyl group in the main chain, R ₁ , R 2
₅ represents a pyromellitic dianhydride residue, and R ₃ represents the following group

[0013]

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[0014] It is selected from the following. ), The polyamic acid copolymer represented by

A second aspect of the present invention for producing the above-mentioned polyamic acid copolymer is that at least one equivalent of the linear diamine defined in the first aspect of the present invention has the following structural formula:

[0016]

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After adding 1 equivalent of a tetracarboxylic dianhydride selected from the above, then adding 2 equivalents of pyromellitic dianhydride, and then adding 1 equivalent of the flexible diamine specified in the first item of the present invention. A method for producing a polyamic acid copolymer,

A third aspect of the present invention for producing the above polyamic acid copolymer is that after adding 2 equivalents of pyromellitic dianhydride to 1 equivalent of the flexible diamine specified in the first aspect of the present invention, 2 equivalents of the linear diamine specified in the first aspect of the present invention were added, and the following structural formula was added.

[0019]

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A method for producing a polyamic acid copolymer, which comprises adding 1 equivalent of a tetracarboxylic dianhydride selected from the group consisting of:

A fourth aspect of the present invention for producing the above polyamic acid copolymer is the following structural formula:

[0022]

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To one equivalent of a tetracarboxylic dianhydride selected from the above, 2 equivalents of the linear diamine specified in the first aspect of the present invention and then 2 equivalents of pyromellitic dianhydride are added. A method for producing a polyamic acid copolymer, characterized by adding 1 equivalent of the flexible diamine specified in the first aspect of the present invention,

A fifth aspect of the present invention for producing the above polyamic acid copolymer is to add 2 equivalents of pyromellitic dianhydride and 1 equivalent of the flexible diamine specified in the first aspect of the present invention. 2 equivalents of the linear diamine specified in the first aspect of the present invention were added, and the following structural formula was added.

[0025]

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A method for producing a polyamic acid copolymer characterized by adding 1 equivalent of a tetracarboxylic dianhydride selected from the group consisting of:

A sixth aspect of the present invention is to provide a polyimide copolymer obtained by dehydrating and cyclizing the polyamic acid copolymer of the first aspect,

According to a seventh aspect of the present invention, there is provided a method for producing a polyimide copolymer, comprising dehydrating and cyclizing the polyamic acid copolymer obtained in the second aspect of the present invention.

An eighth aspect of the present invention is a method for producing a polyimide copolymer, comprising dehydrating and cyclizing the polyamic acid copolymer obtained in the third aspect of the present invention.

A ninth aspect of the present invention is a method for producing a polyimide copolymer, comprising dehydrating and cyclizing the polyamic acid copolymer obtained in the fourth aspect of the present invention.

According to a tenth aspect of the present invention, there is provided a method for producing a polyimide copolymer, comprising dehydrating and cyclizing the polyamic acid copolymer obtained in the fifth aspect of the present invention.

An eleventh aspect of the present invention provides a polyimide film obtained by dehydration-closing the polyamic acid copolymer of the first aspect,

A twelfth aspect of the present invention is a method for producing a polyimide film, comprising casting the polyamic acid copolymer obtained in the second aspect on a support and dehydrating and ring-closing the same.

According to a thirteenth aspect of the present invention, there is provided a method for producing a polyimide film, comprising casting the polyamic acid copolymer obtained in the third aspect on a support and subjecting it to dehydration ring closure.

A fourteenth aspect of the present invention is a method for producing a polyimide film, comprising casting the polyamic acid copolymer obtained in the fourth aspect on a support and dehydrating and ring-closing the polyimide film.

A fifteenth aspect of the present invention relates to a method for producing a polyimide film, comprising casting the polyamic acid copolymer obtained in the fifth aspect on a support and dehydrating and ring-closing the polyimide film. Is what you do.

Hereinafter, the present invention will be described in detail. The linear diamine used in the present invention refers to a diamine compound having a structure that does not include a bending group such as an ether bond and has a structure in which a main chain direction of a diamine matches a straight line connecting two nitrogen atoms. For example,

[0038]

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(Where X is F, Cl, Br, CH ₃ ,
CH ₃ O and CF ₃ are shown. And the like, and these can be used alone or in combination of two or more.

On the other hand, a flexible diamine refers to a structure in which a main chain contains a bending group such as an ether bond or a carbonyl group.

[0041]

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And the like. These can be used alone or in combination of two or more. Also,
If a long-chain diamine is used for the flexible diamine residue (R ₆ ), lower hygroscopicity can be realized.

It is important that the constituent units of the polyamic acid copolymer of the present invention are regularly arranged in the same order as the above structural units. In order to realize this, the following synthesis method is used. Is used. The polyamic acid copolymer solution is obtained by polymerizing in an organic polar solvent using substantially equimolar amounts of an acid anhydride and a diamine component.

The organic polar solvent used in the reaction for producing the polyamic acid copolymer includes, for example, sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, N, N-dimethylformamide, N, N-diethylformamide N, N-
Acetamide solvents such as dimethylacetamide and N, N-diethylacetamide; pyrrolidone solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone; phenol, o-, m- or p-cresol;
Xylenol, halogenated phenols, phenolic solvents such as catechol, or hexamethylphosphoramide, γ-butyrolactone, and the like can be mentioned, and it is preferable to use these alone or as a mixture, and further, xylene, toluene, etc. Partial use of aromatic hydrocarbons is also possible.

A method for synthesizing a polyamic acid copolymer solution will be specifically described. Synthesis Method 1 At least one equivalent of an organic polar solvent and a linear diamine is placed in a vessel in an amount of 2 equivalents, and the mixture is stirred under cooling. One equivalent of at least one of tetracarboxylic dianhydrides selected from the following three is added, and the mixture is cooled and stirred for preferably 20 minutes or more.

[0046]

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Add 2 equivalents of pyromellitic dianhydride to the above mixture,
Preferably, the mixture is cooled and stirred for at least 20 minutes. One equivalent of at least one flexible diamine is dissolved in an organic polar solvent and gradually added with cooling and stirring to obtain the polyamic acid copolymer solution.

Synthesis Method 2 At least one equivalent of an organic polar solvent and a flexible diamine is placed in a container in an amount of 1 equivalent, and cooled and stirred. Add 2 equivalents of pyromellitic dianhydride, preferably 2
Cool and stir for 0 minutes or more. Two equivalents of at least one linear diamine are added, and the mixture is cooled and stirred for preferably 20 minutes or more. The tetracarboxylic dianhydride selected from the above three is 1
One or more equivalents of one or more species are added to the above mixed solution to obtain the polyamic acid copolymer solution.

Synthesis Method 3 One or more equivalents of an organic polar solvent and one or more tetracarboxylic dianhydrides selected from the above three are placed in a vessel and cooled and stirred. Two equivalents of at least one linear diamine are added, and the mixture is cooled and stirred for preferably 20 minutes or more. Add 2 equivalents of pyromellitic dianhydride to the above mixture,
Preferably, the mixture is cooled and stirred for at least 20 minutes. One equivalent of at least one kind of flexible diamine is dissolved in an organic polar solvent, and the solution is gradually added with cooling and stirring to obtain the polyamic acid copolymer.

Synthesis Method 4 An organic polar solvent and 2 equivalents of pyromellitic dianhydride are placed in a vessel, and the mixture is cooled and stirred. One equivalent of at least one flexible diamine is added, and the mixture is preferably cooled and stirred for at least 20 minutes. Two equivalents of at least one linear diamine are added, and the mixture is cooled and stirred for preferably 20 minutes or more. One equivalent of at least one of the tetracarboxylic dianhydrides selected from the above three is added to the above mixed solution to obtain the polyamic acid copolymer solution. The polyamic acid copolymer obtained as described above is preferably dissolved in the organic polar solvent in an amount of 5 to 40% by weight, preferably 10 to 30% by weight, from the viewpoint of handling.

From this aromatic polyamic acid copolymer solution, the following formula

[0052]

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(Where R _{1 to} R ₆ are the same as those described above). In order to obtain the polyimide copolymer and the polyimide film of the present invention having a repeating structural unit represented by the following formula, Any of the chemical methods using a dehydrating agent may be used, but the chemical method is preferred because the resulting polyimide film has excellent mechanical properties such as elongation and tensile strength. Hereinafter, an example of a method for producing a polyimide film will be described.

A solution obtained by adding a dehydrating agent having a stoichiometric amount or more and a catalytic amount of a tertiary amine to the polyamic acid polymer or a solution thereof is cast or coated on a drum or an endless belt to form a film. At a temperature of 150 ° C. or less for about 5
After drying for 90 minutes, a self-supporting polyamic acid film is obtained. Next, this is peeled off from the support and the end is fixed. Thereafter, the polyimide film is gradually heated to about 100 to 500 ° C. to be imidized, and after cooling, is removed from a drum or an endless belt to obtain a polyimide film of the present invention. Examples of the dehydrating agent mentioned here include aliphatic acid anhydrides such as acetic anhydride, aromatic acid anhydrides, and the like. Examples of the catalyst include aliphatic tertiary amines such as triethylamine, aromatic tertiary amines such as dimethylaniline, and heterocyclic tertiary amines such as pyridine, picoline and isoquinoline.

[0055]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, ODA is 4,4'-diaminodiphenyl ether, BAPB is 4,4'-bis (aminophenoxyphenyl) biphenyl, BAPP is 4,4'-bis (aminophenoxyphenyl) propane, and p-PDA is paraphenylene. Diamine, TPE-Q is 1,4-bis (4-aminophenoxy) benzene, PMDA is pyromellitic anhydride, BTDA is benzophenonetetracarboxylic dianhydride, BPDA is biphenyltetracarboxylic dianhydride, DMF is dimethylformamide Represents

Example 1 DMF and p-PDA were placed in a 2-liter separable flask.
Was taken, and mixed well at room temperature until the diamino compound was completely dissolved, and then stirred while cooling with ice. Next, 1 equivalent of BTDA was added at once, and the mixture was cooled and stirred for 40 minutes. Then, 2 equivalents of PMDA were added at once, and the mixture was cooled and stirred for 40 minutes. One equivalent of ODA was dissolved in DMF, and the solution was gradually added, followed by cooling and stirring for 1 hour.
An F solution was obtained. The amount of DMF used was such that the concentration of charged monomers of the diamino compound and the aromatic tetracarboxylic acid compound was 18% by weight. The polyamic acid solution was applied on a glass plate by casting and dried at about 100 ° C. for about 30 minutes. Thereafter, the polyamic acid coating film was peeled off from the glass plate, and the coating film was fixed on a support frame. Minutes,
Heating was performed at about 200 ° C. for about 60 minutes and at about 300 ° C. for about 60 minutes, followed by dehydration ring-closing and drying to obtain a polyimide film of about 25 μm. Table 1 shows the physical properties of the obtained polyimide film.
It was shown to.

Example 2 DMF and p-PDA were placed in a 2-liter separable flask.
Was taken, and mixed well at room temperature until the diamino compound was completely dissolved, and then stirred while cooling with ice. Next, 1 equivalent of BTDA was added, and the mixture was cooled and stirred for 40 minutes. Then, 2 equivalents of PMDA were added at once, and the mixture was cooled and stirred for 40 minutes. Dissolve 1 equivalent of TPE-Q in DMF and slowly add
Thereafter, the mixture was cooled and stirred for 1 hour to obtain a polyamic acid DMF solution. It was fired in the same manner as in Example 1 to obtain a polyimide film. Table 1 shows the physical properties of the obtained polyimide film.

Example 3 DMF and p-PDA were placed in a 2-liter separable flask.
Was taken, and mixed well at room temperature until the diamino compound was completely dissolved, and then stirred while cooling with ice. Next, 1 equivalent of BTDA was added, and the mixture was cooled and stirred for 40 minutes. Then, 2 equivalents of PMDA were added at once, and the mixture was cooled and stirred for 40 minutes. One equivalent of BAPB was dissolved in DMF, added gradually, and then cooled and stirred for 1 hour to obtain a polyamic acid DMF solution. It was fired in the same manner as in Example 1 to obtain a polyimide film. Table 1 shows the physical properties of the obtained polyimide film.

Example 4 DMF and p-PDA were placed in a 2-liter separable flask.
Was taken, and mixed well at room temperature until the diamino compound was completely dissolved, and then stirred while cooling with ice. Next, 1 equivalent of BTDA was added, and the mixture was cooled and stirred for 40 minutes. Then, 2 equivalents of PMDA were added at once, and the mixture was cooled and stirred for 40 minutes. One equivalent of BAPP was dissolved in DMF, added gradually, and then cooled and stirred for 1 hour to obtain a DMF solution of polyamic acid. It was fired in the same manner as in Example 1 to obtain a polyimide film. Table 1 shows the physical properties of the obtained polyimide film.

Example 5 DMF and p-PDA were placed in a 2-liter separable flask.
Was taken, and mixed well at room temperature until the diamino compound was completely dissolved, and then stirred while cooling with ice. Next, 1 equivalent of BPDA was added, and the mixture was cooled and stirred for 40 minutes. Then, 2 equivalents of PMDA were added at once, and the mixture was cooled and stirred for 40 minutes. One equivalent of BAPB was dissolved in DMF, added gradually, and then cooled and stirred for 1 hour to obtain a polyamic acid DMF solution. It was fired in the same manner as in Example 1 to obtain a polyimide film. Table 1 shows the physical properties of the obtained polyimide film.

Comparative Example 1 In the same manner as in Example 1, a polyimide film was obtained using PMDA and ODA in equimolar amounts. Table 1 shows the physical properties of the obtained polyimide film.

Comparative Example 2 DMF and p-PDA were placed in a 2-liter separable flask.
And 2 equivalents of ODA and 1 equivalent of ODA were mixed well at room temperature until the diamino compound was completely dissolved, and then stirred while cooling with ice. Next, 2 equivalents of PMDA and 1 equivalent of BTDA were gradually added, followed by cooling and stirring for 1 hour to obtain a polyamic acid DMF solution. It was fired in the same manner as in Example 1 to obtain a polyimide film. Table 1 shows the physical properties of the obtained polyimide film.

[0063]

[Table 1]

[0064]

As described above, according to the present invention, a polyimide film having excellent heat resistance, high elasticity, low thermal expansion and low moisture absorption can be obtained.

Continuation of front page (56) References JP-A-5-51453 (JP, A) JP-A-5-25273 (JP, A) JP-A-4-335028 (JP, A) JP-A-4-320422 (JP) JP-A-64-20238 (JP, A) JP-A-64-16832 (JP, A) JP-A-1-282218 (JP, A) JP-A-63-254131 (JP, A) 60-210894 (JP, A) JP-A-63-314242 (JP, A) JP-A-63-166287 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08G 73/00 -73/26

Claims (15)

(57) [Claims] [Claim 1] The following formula: (However, R ₂ and R ₄ represent the following groups: (Where X is F, Cl, Br, CH ₃ , CH ₃ O, C
Shows the F _3. A) a linear diamine (hereinafter, referred to as a linear diamine) residue having a structure in which the main chain direction of the diamine does not include a straight line connecting two nitrogen atoms and does not include a bending group such as an ether bond selected from the above. , R ₆ are the following groups: And a flexible diamine (hereinafter, referred to as a flexible diamine) residue having a structure containing a bending group such as an ether bond or a carbonyl group in a main chain thereof, and R ₁ and R ₅ are pyromellitic dianhydrides. R ₃ represents the following group: It was chosen from among A) a polyamic acid copolymer represented by 2. The equivalent of the linear diamine defined in claim 1 to 2 equivalents of the following structural formula: A polyamic acid characterized by adding 1 equivalent of a tetracarboxylic dianhydride selected from the following, then adding 2 equivalents of pyromellitic dianhydride, and then adding 1 equivalent of a flexible diamine specified in claim 1. A method for producing a copolymer. 3. After adding 2 equivalents of pyromellitic dianhydride to 1 equivalent of the flexible diamine specified in claim 1, 2 equivalents of the linear diamine specified in claim 1 are added, and the following structural formula: Formula 6 A method for producing a polyamic acid copolymer, comprising adding 1 equivalent of a tetracarboxylic dianhydride selected from the group consisting of: 4. The following structural formula: After adding 2 equivalents of the linear diamine specified in claim 1 to 1 equivalent of a tetracarboxylic dianhydride selected from the following, and then adding 2 equivalents of pyromellitic dianhydride, the bending defined in claim 1 A method for producing a polyamic acid copolymer, comprising adding 1 equivalent of a reactive diamine. 5. An addition of 2 equivalents of pyromellitic dianhydride to 1 equivalent of a flexible diamine as defined in claim 1 and 2 equivalents of a linear diamine as defined in claim 1 to give the following structural formula: 8] A method for producing a polyamic acid copolymer, comprising adding 1 equivalent of a tetracarboxylic dianhydride selected from the group consisting of: 6. A polyimide copolymer obtained by subjecting the polyamic acid copolymer according to claim 1 to dehydration ring closure. 7. A method for producing a polyimide copolymer, wherein the polyamic acid copolymer obtained in the production method according to claim 2 is subjected to dehydration ring closure. 8. A method for producing a polyimide copolymer, comprising subjecting the polyamic acid copolymer obtained in the production method according to claim 3 to dehydration ring closure. 9. A method for producing a polyimide copolymer, wherein the polyamic acid copolymer obtained in the production method according to claim 4 is subjected to dehydration ring closure. 10. A method for producing a polyimide copolymer, comprising subjecting the polyamic acid copolymer obtained in the method according to claim 5 to dehydration and ring closure. 11. A polyimide film obtained by dehydrating and ring-closing the polyamic acid copolymer according to claim 1. 12. A method for producing a polyimide film, comprising casting the polyamic acid copolymer obtained in the production method according to claim 2 on a support and dehydrating and ring-closing the polyimide film. 13. A method for producing a polyimide film, comprising casting the polyamic acid copolymer obtained in the production method according to claim 3 onto a support and subjecting it to dehydration ring closure. 14. A method for producing a polyimide film, comprising casting the polyamic acid copolymer obtained in the production method according to claim 4 onto a support and dehydrating and ring-closing the polyimide film. 15. A method for producing a polyimide film, comprising casting the polyamic acid copolymer obtained in the production method according to claim 5 on a support and dehydrating and ring-closing.