JP2003119285A - Block copolymer polyimide composition soluble in ketonic and/or ethereal solvent and production method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a block copolymer polyimide composition soluble in a ketonic and/or ethereal solvent which is head to be subject to the influence of water from the surrounding environment. SOLUTION: The solvent of a polyimide is generally a polar solvent such as N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide and dimethyl sulfoxide. These nonaqueous solvents are however sensitive to water and very liable to absorb water, thus causing a whitening phenomenon on the surface of a polyimide. The solubility of a polyimide is improved by blocking the composition of the polyimide by using a lactone and a base as catalysts, so that the polyimide becomes soluble in a ketonic and/or ethereal solvent, in which the polyimide has not hitherto been soluble. Since the ketonic and ethereal solvent is scarcely affected by water, the whitening phenomenon on the surface of a polyamide due to moisture absorption can be suppressed to the utmost.

Description

Detailed Description of the Invention

TECHNICAL FIELD The present invention relates to a polyimide composition soluble in a ketone and / or ether solvent and a method for producing the same. Polyimide has excellent heat resistance,
As it has electrical insulation, mechanical properties and chemical resistance, it can be used for electrical and electronic parts, semiconductors, communication equipment and peripheral parts,
Applied to circuits.

[Prior Art] Since a polyimide resin is hardly soluble in an organic solvent, polyamic acid is used in a polar solvent.
Then, it was necessary to heat and dehydrate to form a film.

Recently, solvent-soluble polyimides have been found,
It is used as an alignment film for liquid crystals and as an insulating film for flexible substrates for coating.

However, as a dissolving solvent, N-methylpyrrolidone, N, N-dimethylformamide, N, N-
Nonaqueous solvents such as dimethylacetamide and dimethylsulfoxide have been used.

Polyimide varnishes and polyimide inks using these non-aqueous solvents have the drawback that when used in an environment where the relative humidity exceeds 50%, the surfaces of the films and molded products obtained are whitened.

[0006] Even if these whitened films and molded products are heated and dried, not only polyimide's original tough film is not obtained, but also original properties such as electric characteristics cannot be obtained.

The cause of this whitening is N-methylpyrrolidone, which is the solvent used to dissolve the polyimide.
This is because non-aqueous solvents such as N, N-dimethylformamide and dimethyl sulfoxide have high water absorption.

Therefore, in order to use the polyimide resin dissolved in these solvents for coating or the like, it is necessary to blow dry air or nitrogen gas into the coating device, or to cover the coating device so that moisture does not enter from the surroundings. there were.

When used as an electronic material,
It is necessary to remove dust and impurities from the polyimide resin with a fine filtration device, and in this case also, replace the filtration device and the receiver such as the bottle with dry air or nitrogen gas, or cover it so that moisture does not enter from the surroundings. It was necessary to devise.

Further, in the step of converting these polyimide resins into ink, dry air or nitrogen gas is similarly blown in the step of mixing with a filler by a roll treatment or a mill.
Alternatively, it was necessary to cover the entire device to prevent water from getting in from the surroundings.

Even with such a contrivance, there was a defect that a slight amount of water entered during the storage of the polyimide resin, the viscosity of the resin changed, and the polyimide resin could not be used repeatedly.

[Problems to be Solved by the Invention] An object of the present invention is to produce N-, which has a high water absorbency and causes the whitening phenomenon.
It is to provide a block copolymerized polyimide composition that is soluble in ketones and ethers that have been considered to be insoluble in the past, which is completely different from non-aqueous solvents such as methylpyrrolidone, N, N-dimethylformamide, and dimethylsulfoxide. .

[Means for Solving the Problems] As a result of earnest studies, the present inventors have found that a block copolymerized polyimide composition soluble in a ketone and / or an ether that is hardly affected by moisture from the surroundings and a method for producing the same. Heading, completed the present invention.

A soluble block copolymerized polyimide composition is synthesized by sequentially reacting a tetracarboxylic dianhydride and a diamine in a ketone and / or ether solvent in the presence of an acid catalyst.

The tetracarboxylic acid dianhydride is 3,
3 ', 4,4'-biphenyl tetracarboxylic acid dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic acid dianhydride, 3,3 ', 4,4'-biphenyl ether tetracarboxylic acid dianhydride Anhydride, 3,3 ', 4,4'-diphenylsulfone tetracarboxylic acid dianhydride, bicyclo (2,2,2) -oct-7-ene-2,3,5,6-
Tetracarboxylic acid dianhydride, 1,2,4,5-cyclohexane tetracarboxylic acid dianhydride, pyromellitic acid dianhydride, 2,2-bis (3,4-dicarboxylicoxyphenyl) hexafluoropropane dianhydride , 5- (2,5-
Examples thereof include dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, and these can be used alone or in combination of two or more kinds.

As the diamine, siloxane diamine,
Bis (3-aminopropyl) etherethane, N, N-
Bis (3-aminopropyl) ether, 1,4 bis (3
-Aminopropyl) piperazine, isophoronediamine,
1,3'-bis (aminomethyl) cyclohexane, 3,
3'-dimethyl-4,4'-diaminodicyclohexanemethane, 4,4'-methylenebis (cyclohexylamine), 4,4'-diaminodiphenyl ether, 3,
4'diaminodiphenyl ether, 1,3-bis (4-
Aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy)) Phenyl] hexafluoropropane, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, 4,4′bis (4-aminophenoxy) biphenyl, 1,4 -Bis (4-aminophenoxy) benzene, 4,4'-diaminodiphenyl sulfide, 3,3 'diamino-4,4' dihydroxybiphenyl sulfone and the like, which may be used alone or
Combinations of more than one type can be used.

Silicone diamine is commercially available BY
16-853U, BY16-853C (Product of Toray Radar Corning Silicone Co., Ltd., trade name), X-22
-1660B-3, KF-8010, X-22-161
A (product of Shin-Etsu Chemical Co., Ltd., trade name) and the like can be used.

A block copolymerized polyimide in a ketone, an ether or a mixed solvent of a ketone and an ether is prepared by heating a tetracarboxylic acid in a solvent of a ketone, an ether or a mixed solvent of a ketone and an ether in the presence of an acid catalyst formed by a lactone and a base. The dianhydride and diamine are dehydrated and imidized, and water produced during the reaction is removed from the reaction system by azeotropic distillation with the reaction solvent. When synthesizing in a polar solvent such as NMP, toluene is added as an azeotropic solvent.

Usually, the solvent for polyimide is a polar solvent such as N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide or dimethylsulfoxide. It is also possible to synthesize these solvents by adding polyimide to a ketone and / or ether solvent at 40 wt% or less.

As the lactone, γ-valerolactone is used,
As the base, pyridine, N-methylmorpholine or the like is used,
The acid generated by the equilibrium reaction can be used as a catalyst.

The multi-component block copolymer can be improved in photosensitivity, adhesiveness, water repellency, mechanical properties, etc. by incorporating a functional part and a structural part in the molecule. By making the solvent-soluble polyimide oligomer in the first step reaction, the solubility of the polyimide, which is hardly soluble in the ketone, the ether, or the mixed solvent of the ketone and the ether, can be increased.

The ketone solvent of the present invention must be easy to work in coating and mixing steps, and the solvent after molding must be easily removed.
It is desirable that the temperature is ℃ or less.

As such a ketone solvent, methyl ethyl ketone, methyl propyl ketone, methyl isopropyl ketone, methyl butyl ketone, methyl isobutyl ketone, methyl n-hexyl ketone, diethyl ketone, diisopropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone , Methylcyclohexanone,
Acetylacetone, diacetone alcohol and cyclohexen-1-one are used.

In particular, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, acetylacetone and diacetone alcohol are inexpensive and most suitable as general-purpose solvents.

The ether solvent of the present invention is required to be easy to work in coating and mixing steps, and to be able to easily remove the solvent after molding.
It is preferably 0 ° C or lower.

Examples of such ether solvents include dipropyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, tetrahydropyran, ethyl isoamyl ether, ethyl-t-butyl ether, ethyl benzyl ether, diethylene glycol dimethyl ether, cresyl methyl ether, anisole. , Phenetole is used.

In particular, tetrahydrofuran, anisole,
Phenetol and diethylene glycol dimethyl ether are inexpensive and most suitable as general-purpose solvents.

Of course, these solvents can be used alone, but they may be used as a mixture, and it goes without saying that the mixing ratio has an optimum range depending on the resin composition.

In the coating and drying steps, the mixed system is preferable because the polyimide resin composition can be used stably.

When it is difficult to dissolve in a ketone, an ether or a mixed solvent of a ketone and an ether depending on the composition of the polymer, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide and the like can be further mixed. . The amount thereof is 40% or less of the total solvent, preferably 20% or less. Within this range, whitening can be suppressed to some extent.

When the molecular weight is high, the solubility in a solvent tends to be poor.

Therefore, the polystyrene reduced weight average molecular weight of the block copolymerized polyimide soluble in ketone, ether or a mixed solvent of ketone and ether is 10.000-2.
The range of 0.0000 is practical.

A method for synthesizing a block copolymerized polyimide which is soluble in a ketone, an ether or a mixed solvent of a ketone and an ether will be specifically illustrated in Examples 1, 2 and 3.

The solvent for the polyimide is usually a polar solvent such as N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide or dimethylsulfoxide.

Each of these solvents has a high boiling point and cannot be easily replaced with the ketone and ether used in the present invention.

Therefore, it is necessary to remove the reaction solvent by precipitating the polyimide synthesized with a polar solvent such as NMP using a poor solvent such as methanol.

These steps may be a general method for purifying a polymer resin.

After the resin is precipitated, it is filtered and dried.

The dried block copolymerized polyimide powder is dissolved in ketone, ether or a mixed solvent of ketone and ether.

At this time, if it is difficult to dissolve, it is dissolved by heating within a range up to the boiling point of the solvent.

If necessary, the time required for dissolution can be shortened by performing the stirring.

A block copolymerized polyimide is synthesized in a polar solvent such as NMP, precipitated, washed and dried with a poor solvent such as methanol, and then the polyimide powder is redissolved in a solvent such as ketone, ether or a mixed solvent of ketone and ether. A method for producing a soluble block copolymerized polyimide, which is characterized in that: is specifically illustrated in Examples 4 and 5.

[Examples] The present invention is described in detail below with reference to some examples. The present invention is not limited to these examples, since a solvent-soluble block-copolymerization polyimide composition having characteristics can be obtained by combining various tetracarboxylic dianhydrides, diamines and solvents.

[Example 1] 3.4.3 '. 4'-biphenyltetracarboxylic dianhydride (Ube Industries, Ltd., molecular weight 2
94.25, hereinafter referred to as BPDA) 4.41 g (15 mmol), 2,2-bis [4- (4-aminophenoxy) phenyl] propane (manufactured by Wakayama Seika, molecular weight 41)
0.5, hereinafter referred to as BAPP) 12.32 g (30 mmol), 0.15 g of γ-valerolactone as a catalyst
(1.5 mmol) and 2.4 g (3 mmol) of pyridine, and 64.75 g of anisole as a solvent were charged.
First, 0.5 at 100 rpm in a nitrogen atmosphere at room temperature.
After stirring for hr and forming a uniform solution, the temperature was raised in an oil bath at 180 ° C., and the mixture was stirred at 180 rpm for 1 hour. Azeotropic water was removed during the reaction. After the one-step reaction is completed, cool to room temperature,
BPDA 8.83 g (30 mmol), silicone oil (To-Lead Corning Silicone product By-85
13.80 g (15 mmol) of 3U) and 150 g of anisole as a solvent were further charged. 100 at room temperature
After stirring at rpm for about 1 hour, the temperature was raised in an oil bath at 180 ° C., and the mixture was stirred at 180 rpm for 2 hours and 45 minutes for reaction. During that time, the water collected was drained every hour. The polymer concentration of the polyimide solution thus obtained is 15 wt%
When the molecular weight of this polyimide was measured by gel permeation chromatography (Toso product), the polystyrene reduced molecular weight was the number average molecular weight (Mn).
9225, weight average molecular weight (Mw) 21437, Z average molecular weight (Mz) 37515, Mw / Mn = 2.32, M
It was z / Mn = 4.07.

[Example 2] 5.88 g (20 mmol) of BPDA, silicone oil (product of Toray Dan Colling Co., product number By16-853U, amine equivalent: 46)
0) 9.20 g (10 mmol,) 0.3 g (3 mmol) of γ-valerolactone and 0.
47 g (6 mmol), 40 g of anisole as a solvent,
11 g of NMP was charged. First, at room temperature, the mixture was stirred under a nitrogen atmosphere at 100 rpm for 0.5 hr to form a uniform solution, which was then heated in an oil bath at 180 ° C. and stirred at 180 rpm for 1 hour. Azeotropic water was removed during the reaction. After the completion of the one-step reaction, the mixture was cooled to room temperature, and bicyclo [2,2,2] oct-2-ene-2,3,5,6-tetracarboxylic dianhydride (manufactured by Aldrich, molecular weight 248.19, hereinafter BC
2.48 g (10 mmol), isophorone diamine (product of Tokyo Kasei, molecular weight 170.25) 3.4
1 g (20 mmol), and anisole 3 as a solvent
Charged 9.56 g. After stirring at room temperature at 100 rpm for about 1 hour, the temperature was raised in an oil bath at 180 ° C for 180 r
The reaction was allowed to stir at pm for 4 hours. During that time, the water collected was drained every hour. The polymer concentration of the polyimide solution thus obtained was 18 wt%. When the molecular weight of this polyimide was measured by gel permeation chromatography (Toso product), the polystyrene reduced molecular weight was the number average molecular weight (Mn ) 11481, weight average molecular weight (Mw) 24431, Z average molecular weight (Mz) 3
9756, Mw / Mn = 2.13, Mz / Mn = 3.3
It was 8.

Example 3 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-
1,2-dicarboxylic acid anhydride (manufactured by Tokyo Kasei Co., molecular weight 2
64.23, hereinafter referred to as CP acid) 10.57 g (40 mmol), bis [4- (3-aminophenoxy) phenyl] sulfone (manufactured by Wakayama Seika, molecular weight 432.5, hereinafter referred to as m-BAPS) 8.65 g (20 mmol), 0.4 g (4 mmol) of γ-valerolactone as a catalyst
Then, 0.63 g (8 mmol) of pyridine and 20 g of cyclohexanone as a solvent were charged. First, at room temperature, under a nitrogen atmosphere, stirring was performed at 100 rpm for 0.5 hr to form a uniform solution, and then the temperature was raised in an oil bath at 180 ° C. to 180 rp.
It was stirred at m for 1 hour. Azeotropic water was removed during the reaction. After the completion of the one-step reaction, the mixture was cooled to room temperature and 8.21 g of BAPP
(20 mmol), and 40.64 g of cyclohexanone was further charged as a solvent. After stirring at room temperature at 100 rpm for about 1 hour, raise the temperature in an oil bath at 180 ° C to 180
The reaction was carried out by stirring at rpm for 2 hours. During that time, the water collected was drained every hour. The polymer concentration of the polyimide solution thus obtained was 30 wt%. When the molecular weight of this polyimide was measured by gel permeation chromatography (Toso product), the polystyrene reduced molecular weight was the number average molecular weight (Mn ) 7042, weight average molecular weight (Mw) 11574, Z average molecular weight (Mz) 1
7551, Mw / Mn = 1.64, Mz / Mn = 2.4
It was 9.

Example 4 35.31 g (12) of BPDA
0 mmol), silicone oil (product of Toray Dunkoling Co., product number By16-853U, amine equivalent: 4)
60) 55.54 g (60 mmol) of catalyst, γ-
Valerolactone 1.8 g (18 mmol) and pyridine 2.85 g (36 mmol), N-methylpyrrolidone (hereinafter referred to as NMP) 150 g as a solvent, toluene 40
I charged g. First, 100 at room temperature under a nitrogen atmosphere.
Stir at 0.5 rpm for 0.5 hr to form a uniform solution, then 1
The temperature was raised in an oil bath at 80 ° C., and the mixture was stirred at 180 rpm for 1 hour. During the reaction, an azeotropic component of toluene and water was removed. After the one-step reaction was completed, the mixture was cooled to room temperature and 17.65 g (6
0 mmol), silicone oil (Toray-Dow Corning Silicone Co. By-853U) 27.60 g (3
0 mmol), 3,4 ′ diaminodiphenyl ether (manufactured by Wakayama Seika, molecular weight 200.2, hereinafter m-DADE
12.01 g (60 mmol), 1,3-bis (4-aminophenoxy) benzene (manufactured by Wakayama Seika, molecular weight 292.34, hereinafter referred to as m-TPE) 8.77 g
(30 mmol) Further, 200 g of NMP and 30 g of toluene were charged as a solvent. After stirring at room temperature at 100 rpm for about 1 hour, heat the bath to 180 ° C. and
Reaction was carried out by stirring at rpm for 4 hours and 30 minutes. During that time, the toluene and water azeotrope were drained once every hour. The polymer concentration of the polyimide solution thus obtained was 30 wt%.

After cooling the polyimide varnish obtained by the above synthesis method to room temperature, it is gradually added to methanol while stirring, and the resulting polyimide precipitate is finely pulverized with a mixer to obtain a pulverized polyimide powder. It was washed 3 times with methanol and filtered by suction filtration. The polyimide powder thus obtained was dried at room temperature for 3 hours, 60 ° C. for 1 hour, and 90 ° C. for 1 hour using a vacuum dryer.
Anisole was added to the dried polyimide powder so that the solid content was 24%, and the mixture was stirred at room temperature for about 30 minutes to melt some powders, but most of them were powders.
The temperature was raised to 0 ° C. and the mixture was stirred for about 30 minutes, and the polyimide powder was melted to form a uniform solution. It remained fluid even when cooled to room temperature. When the molecular weight of this polyimide was measured by a gel permeation chromatography method (Toso product), the polystyrene reduced molecular weight was the number average molecular weight (Mn).
13890, weight average molecular weight (Mw) 31456, Z average molecular weight (Mz) 47203, Mw / Mn = 2.26,
It was Mz / Mn = 3.39.

This polyimide solution did not show any increase in viscosity even after 2 weeks, and kept its fluidity. The temperature is 2
An ink for screen printing was prepared using this liquid in an environment of 5 ° C. and a humidity of 60%. Three rolls are used to mix the filler with the polyimide varnish, and the surface area of the polyimide that comes into contact with the air increases while kneading with the rolls, which makes it considerably susceptible to the moisture contained in the air. Usually, when NMP is used as the solvent, NMP absorbs moisture within 10 minutes and the surface of the polyimide becomes white. However, when anisole was used as the solvent, it was hardly affected by moisture in the air when kneading with a roll, and no whitening phenomenon was observed on the surface of the polyimide even after 40 minutes of exposure to the air.

[Example 5] The same operation as in Example 1 was carried out.
3,4,3 ′, 4′-benzophenone tetracarboxylic acid dianhydride (Himie Linz Ges.mbh product, molecular weight 322.23, hereinafter referred to as BTDA) 25.
78 g (80 mmol), isophorone diamine 6.81
g (40 mmol), 1.20 g (12 mmol) of γ-valerolactone as a catalyst and 1.90 (2
4 mmol), N-methylpyrrolidone 100 as a solvent
g, 30 g of toluene are charged. The mixture was stirred at 100 rpm under a nitrogen atmosphere at room temperature for 0.5 hr for 0.5 hr to form a uniform solution, which was heated to 180 ° C. and stirred at 180 rpm for 1 hour. During the reaction, an azeotropic component of toluene and water was removed. After cooling to room temperature, 34.6 g (80 mmol) of m-BAPS, cyclohexane-1,2,4,5-tetracarboxylic dianhydride (manufactured by Shin Nippon Rika Co., Ltd., molecular weight 226.25, hereinafter H
-PMDA) 9.05 g (40 mmol), N-methylpyrrolidone 115.76 g and toluene 30 g as a solvent were added, and the mixture was stirred at room temperature for 1 hour and then 180 ° C, 180
Stir at rpm for 3 hours. The polymer concentration of the polyimide solution thus obtained was 25 wt%.

After cooling the polyimide varnish obtained by the above synthesis method to room temperature, it is gradually added to methanol while stirring, and the resulting polyimide precipitate is finely pulverized with a mixer to obtain a pulverized polyimide powder. It was filtered and washed 3 times with methanol. The thus obtained polyimide powder is further heated at room temperature for 3 hours and then at 60 ° C. for 1 hour and further at 90 ° C.
Dried in a vacuum dryer for 1 hour. Cyclohexanone was added to the dried polyimide powder so that the solid content was 20%, and the mixture was stirred at room temperature for 30 minutes to dissolve some powders, but most of them are still powders. The temperature was raised to 100 ° C. and the mixture was stirred for 30 minutes to uniformly dissolve the polyimide powder. When the molecular weight of this polyimide was measured by a gel permeation chromatography method (Toso product), the polystyrene reduced molecular weights were number average molecular weight (Mn) 18664, weight average molecular weight (Mw) 102276, and Z average molecular weight (M
z) 325769, Mw / Mn = 5.47 This polyimide solution was applied onto a SUS substrate using a spinner,
No whitening phenomenon was observed on the surface of the polyimide coating film even if left for 30 minutes. On the other hand, when polyimide using NMP as a solvent was used, the surface of the polyimide gradually became white from the surroundings within 5 minutes without standing. About 1
The whole thing became white after 0 minutes.

[Effects of the Invention] As described above, according to the present invention, when a polyimide or the like is mixed with a filler using a mortar, an automatic mortar, a boll meal, a triple roll, or the like, it is not easily affected by moisture in the air. Become. Moreover, when the film is formed by a method such as a die coater, a curtain coater, a roll coater, a gravure coater, a screen printing, and a spinner, it is less susceptible to the moisture in the air, and polyimide can be used even in an environment with a certain amount of humidity.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Itaya             1-17-1 Namiki, Kanazawa-ku, Yokohama-shi, Kanagawa             605 F-term (reference) 4J043 PA04 PA09 QB15 QB26 QB31                       RA35 SA06 SA42 SA43 SA71                       SB01 SB02 SB03 TA22 TB01                       TB02 TB03 UA042 UA082                       UA121 UA122 UA131 UA132                       UA141 UA151 UA381 UA662                       UA672 UA761 UA781 UB011                       UB021 UB061 UB062 UB121                       UB122 UB131 UB152 UB281                       UB301 UB302 UB351 UB402                       VA011 VA021 VA022 VA031                       VA041 VA051 VA061 VA062                       VA071 VA081 VA091 WA09                       WA16 XA03 XA13 XA16 XA18                       XA19 XB02 XB03 XB17 XB20                       XB37 ZA12 ZA31 ZA46 ZB47                       ZB50

Claims (11)

[Claims] 1. A tetracarboxylic dianhydride and a diamine are dehydrated and condensed by heating in a ketone and / or ether solvent so that the solid content of polyimide is 10 wt% or more in the presence of a catalyst of lactone and base. The obtained soluble block copolymerized polyimide composition. 2. The tetracarboxylic dianhydride according to claim 1, which is 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride or 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride. Anhydride, 3,3 ', 4,4'-biphenyl ether tetracarboxylic acid dianhydride, 3,3', 4
4'-diphenylsulfone tetracarboxylic acid dianhydride,
Bicyclo (2,2,2) -oct-7-ene-2,3
5,6-Tetracarboxylic acid dianhydride, 1,2,4,5-
Cyclohexanetetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxylicoxyphenyl) hexafluoropropane dianhydride, pyromellitic dianhydride, 5-
Examples include (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, which may be used alone or in combination of two or more kinds. 3. The diamine of claim 1 includes silicone diamine, bis (3-aminopropyl) etherethane, N, N-bis (3-aminopropyl) ether,
1,4bis (3-aminopropyl) piperazine, isophoronediamine, 1,3'-bis (aminomethyl) cyclohexane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 4,4'-methylenebis ( Cyclohexylamine), 4,4'- (or 3,4'-,
3,3 '-, 2,4'-) diamino-biphenyl ether, 4,4 '-(or 3,4'-, 3,3 '-) diamino-diphenylmethane, 4,4'-(or 3,4'- 4 '
-, 3,3 '-) diamino-diphenyl sulfone, 4,
4 '-(or 3,4'-, 3,3 '-) diamino-diphenyl sulfide, 2,4- (or 2,5-) diaminotoluene, 1,3-bis (4-aminophenoxy)
Benzene, 1,3-bis (3-aminophenoxy) benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2.2-bis [4- (4-aminophenoxy) phenyl] hexa Fluoropropane, bis [4- (4-aminophenoxy) phenyl] sulfone,
Bis [4- (3-aminophenoxy) phenyl] sulfone, 4,4′bis (4-aminophenoxy) biphenyl, 1,4-bis (4-aminophenoxy) benzene,
Examples include 4,4′-diaminodiphenyl sulfide and 3,3′diamino-4,4′dihydroxybiphenyl sulfone, and these can be used alone or in combination of two or more kinds. 4. A tetracarboxylic dianhydride and a diamine are heated in a ketone and / or ether solvent at 160 ° C. to 200 ° C. in the presence of an acid catalyst formed by a lactone and a base,
An oligomer of polyimide is prepared, and then tetracarboxylic acid dianhydride and / or diamine are added so that the molar ratio of total tetracarboxylic acid dianhydride and total diamine becomes 0.95 to 1.05, and the three components are sequentially reacted. The above block copolymerized polyimide is synthesized. 5. The lactone of claim 1 is γ-valerolactone, and the base is pyridine and / or N-methylmorpholine. 6. The ketone solvent of claim 1 has a boiling point of 80 ° C. or higher and 180 ° C. or lower, and is methyl ethyl ketone, methyl propyl ketone, methyl isopropyl ketone, methyl butyl ketone, methyl isobutyl ketone, methyl n-hexyl ketone, diethyl ketone, diisopropyl. Ketones, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, acetylacetone, diacetone alcohol, cyclohexen-1-one are used. 7. The ether solvent according to claim 1 has a boiling point of 60 ° C.
Above 200 ° C., dipropyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, tetrahydropyran, ethyl isoamyl ether,
Ethyl-t-butyl ether, ethylbenzyl ether, diethylene glycol dimethyl ether, cresyl methyl ether, anisole and phenetole are used. 8. The ketone or ether shown in claim 6 or 7 is used alone or in combination as a solvent. 9. The weight average molecular weight of the block copolymerized polyimide is 10.000 to 200.000.
(Measured by gel permeation chromatography and converted to standard polystyrene) 10. N-methylpyrrolidone, 40% by weight or less of the total solvent in a ketone and / or ether solvent, N, N-
Dimethylformamide, N, N dimethylacetamide,
Dimethyl sulfoxide or the like can be mixed. 11. A block copolymerized polyimide obtained by synthesizing in a polar solvent such as N-methylpyrrolidone, N, N-dimethylformamide, N, N dimethylacetamide, dimethylsulfoxide, and the like, using a poor solvent such as methanol. It can be redissolved in a ketone and / or ether solvent after filtration, drying.