JP2605176B2 - Method for producing polyimide - Google Patents

Description

The present invention relates to a method for producing a polyimide. More particularly, it relates to an improved method for producing a polyimide having good thermal stability.

[Conventional technology]

Conventionally, polyimides obtained by the reaction of a diamine compound and a tetracarboxylic dianhydride have excellent mechanical strength and dimensional stability in addition to high heat resistance, and properties such as flame retardancy, electrical insulation, and chemical resistance. In order to combine these, they are widely used in the fields of electric / electronic equipment, aerospace equipment, transportation equipment, and the like, and a number of production methods are being studied.

For example, Japanese Patent Publication No. 36-10999 discloses that a diamine compound and a tetracarboxylic dianhydride are reacted in an amide solvent to produce a polyamic acid which is a precursor of a polyimide, and then an imidizing agent such as acetic anhydride. A method has been proposed in which a polyimide having a repeating structural unit corresponding to this polyamic acid is obtained by chemically imidizing the compound with a polyamic acid.

However, this method is not preferable from an industrial point of view in that it takes a lot of time to polymerize the polyamic acid, which is a precursor of the polyimide, and the storage stability of the polyamic acid is not good, and also, the chemical imidization is not preferable. It is difficult to remove the acetic acid generated at that time from the target polyimide, and when polyimide containing acetic acid is used as a molding material, there is a problem that foaming is caused.

As a method for solving such problems, a method of reacting a diamine compound with a tetracarboxylic dianhydride in a phenolic solvent such as cresol to obtain a polyimide by a heat dehydration reaction (FW Harris et al., Applied pol.
y. Symposium, No. 26, pp. 421-428 (1975) ,;
56 etc.) have been proposed.

In such a method, the problem of the method of generating a polyamic acid in a phenol solvent and subsequently performing imidation to generate a polyamic acid in the amide-based solvent and then chemically imidizing in acetic anhydride. Has been improved.

The method proposed by Harris et al. Is a method for producing a polyamic acid-cresol solution using m-cresol as a solvent and isoquinoline as a catalyst. However, in this method, the tetracarboxylic dianhydride used is a phenylated bisphthalic anhydride having a special structure represented by the following general formulas (1) and (2), and is generally used industrially. There is no known example of using tetracarboxylic dianhydride having low solubility in a solvent represented by pyromellitic dianhydride or benzophenone tetracarboxylic dianhydride.

That is, these methods also have a problem in that oligomers are generated from the difference in solubility of the diamine compound and the tetracarboxylic dianhydride in the phenolic solvent, and the thermal stability of the polyimide is poor by including this component. And the use of tetracarboxylic dianhydride having a specific structure which is structurally modified in order to enhance the solubility in a phenolic solvent.

[Problems to be solved by the invention]

A first object of the present invention is to provide a method for easily producing a polyimide having excellent properties.

A second object of the present invention is to provide a method for producing polyimide, which can stably supply polyimide powder having good thermal stability.

[Means for solving the problem]

The present inventors have conducted intensive studies to achieve the above object, and as a result, previously prepared a monomer solution in which a diamine compound and a tetracarboxylic dianhydride were respectively dissolved in a phenolic solvent, and mixed the monomer solutions. Then, the polymerization reaction is started, and then, by heating and performing a dehydration ring-closing reaction, a polyimide having good heat stability can be obtained.In the above method, the tetracarboxylic dianhydride is converted to a phenol-based By preparing a monomer solution dissolved in a solvent in the presence of an organic base, a more remarkable effect is exhibited.Furthermore, a diamine compound and tetracarboxylic dianhydride are dissolved in a phenol solvent in which an organic base is present. To produce a polyamic acid solution, followed by heating to carry out a dehydration ring-closure reaction, thereby achieving thermal stability. It found such that good polyimide is obtained, and have completed the present invention.

That is, the present invention relates to a compound represented by the general formula (I) H ₂ N—R ₁ —NH ₂ (I) wherein R ₁ is an aliphatic group, a cycloaliphatic group, a monocyclic aromatic group, A divalent group selected from the group consisting of an aromatic group, a non-fused cyclic aromatic group in which the aromatic groups are connected directly or by a bridge member) and a diamine compound represented by the general formula (II): (Wherein, R ₂ is an aliphatic group, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, a non-condensed cyclic aromatic group in which aromatic groups are connected directly or by a bridge member. A tetravalent group selected from the group consisting of groups represented by the general formula (III): (Wherein R ₁ and R ₂ are each an aliphatic group, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, or a non-fused R ₁ represents a divalent group and R ₂ represents a tetravalent group, which is selected from the group consisting of polycyclic aromatic groups. The diamine compound represented by formula (II) and the tetracarboxylic dianhydride represented by the general formula (II) are dissolved in a phenolic solvent, polymerization is initiated to produce a polyamic acid, and then reacted at a temperature of 100 ° C. or higher to obtain an imide ring. A method of producing a polyimide corresponding to a raw material monomer while removing water of reaction generated as a result of the conversion, and (1) a solution in which a diamine compound is dissolved in a phenolic solvent; Dianhydrides containing organic bases And (2) reacting a diamine compound and a tetracarboxylic dianhydride in a phenolic solvent in the presence of an organic base. And heat-imidizing the resulting polyamic acid solution.

As the diamine compound represented by the general formula (I) applicable to the method of the present invention, in the general formula (I), R ₁ is an aliphatic group; ethylenediamine, m-aminobenzylamine, p-aminobenzylamine and the like. R ₁ is a cycloaliphatic group; 1,4-diaminocyclohexane and the like, R ₁ is a monocyclic aromatic group; m-phenylenediamine,
R ₁ is a condensed polycyclic aromatic group such as o-phenylenediamine and p-phenylenediamine; R ₁ is a non-condensed cyclic aromatic group in which an aromatic group is directly connected, such as 2,6-diaminonaphthalene. R ₁ is a non-fused cyclic aromatic group in which aromatic groups are connected by a bridge member, such as 4,4′-diaminobiphenyl, 4,3′-diaminobiphenyl; bis (3-aminophenyl) ether;
(3-aminophenyl) (4-aminophenyl) ether, bis (4-aminophenyl) ether, bis (3-aminophenyl) ether
Aminophenyl) sulfide, (3-aminophenyl)
(4-aminophenyl) sulfide, bis (4-aminophenyl) sulfide, bis (3-aminophenyl) sulfoxide, (3-aminophenyl) (4-aminophenyl) sulfoxide, bis (4-aminophenyl) sulfoxide, bis (4-aminophenyl) sulfoxide (3-aminophenyl) sulfone, (3
-Aminophenyl) (4-aminophenyl) sulfone,
Bis (4-aminophenyl) sulfone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone,
4,4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,
4'-diaminodiphenylmethane, bis [4- (3-aminophenoxy) phenyl] methane, bis [4- (4-
Aminophenoxy) phenyl] methane, 1,1-bis [4
-(3-aminophenoxy) phenyl] ethane, 1,1-
Bis [4- (4-aminophenoxy) phenyl] ethane, 1,2-bis [4- (3-aminophenoxy) phenyl] ethane, 1,2-bis [4- (4-aminophenoxy) phenyl] ethane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4-
(4-aminophenoxy) phenyl] propane, 2,2-
Bis [4- (3-aminophenoxy) phenyl] butane, 2,2-bis [4- (4-aminophenoxy) phenyl] butane, 2,2-bis [4- (3-aminophenoxy) phenyl] -1 , 1,1,3,3,3-hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 3-bis (3-aminophenoxy) benzene, 1,3-bis (3
-Aminophenoxy) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (3-aminophenoxy) biphenyl, 4,4 ' -Bis (4-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy)
Phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (3-
Aminophenoxy) phenyl] sulfoxide, bis [4
-(4-aminophenoxy) phenyl] sulfoxide,
Bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-amino) Phenoxy) phenyl] ether, 1,4-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3
-Aminophenoxy) benzoyl] benzene, 4,4'-
Bis [3- (4-aminophenoxy) benzoyl] diphenyl ether, 4,4'-bis [3- (3-aminophenoxy) benzoyl] diphenyl ether, 4,4'-bis [4- (4-amino-α, α -Dimethylbenzyl) phenoxy] benzophenone, 4,4'-bis [4- (4-
Amino-α, α-dimethylbenzyl) phenoxy] diphenylsulfone; bis [4- {4- (4-aminophenoxy) phenoxy} phenyl] sulfone;

Among these diamine compounds, the diamine compound used in the present invention as a particularly useful polyimide raw material is represented by the general formula (I) in which R ₁ is a group represented by the formula (V) (Wherein X ₁ is a direct bond, -CH _2- , -S -, - O -, - SO 2 -, - CO-, (Where Y ₁ is a direct bond, -S -, - O -, - SO 2 -, - CO-, Is a group represented by the following formula :). Specific examples of the compound include the compounds described above.

The tetracarboxylic dianhydride represented by the general formula (II) applicable to the method of the present invention includes a compound represented by the general formula (I
In I), for example, R ₂ is an aliphatic group; ethylene tetracarboxylic dianhydride, butane tetracarboxylic dianhydride, etc .; R ₂ is a cycloaliphatic group; cyclopentane tetracarboxylic dianhydride , Cyclohexanetetracarboxylic dianhydride, R ₂ is a monocyclic aromatic group; 1,2,3,4-benzenetetracarboxylic dianhydride, pyromellitic dianhydride, R ₂ is condensed A polycyclic aromatic group; 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalene Tetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, etc., R ₂ is a non-fused cyclic aromatic group linked directly to an aromatic group; 3,3 ', 4,4'-biphenyl Le tetracarboxylic dianhydride, 2,2 ', 3,3'-biphenyl tetracarboxylic dianhydride, R ₂ is a non-fused cyclic aromatic groups linked by a bridge member to an aromatic group; 3, 3 ', 4,4'-benzophenone tetracarboxylic dianhydride, 2,2', 3,3'-benzophenone tetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride Anhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (2,3-dicarboxyphenyl) ether dianhydride Product, bis (3,4-dicarboxyphenyl) sulfone dianhydride, bis (2,3-
Dicarboxyphenyl) sulfone dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-di Carboxyphenyl) methane dianhydride, 4,4 '
-(P-phenylenedioxy) diphthalic dianhydride, 4,
4 '-(m-phenylenedioxy) diphthalic dianhydride and the like.

In these tetracarboxylic dianhydrides, the compounds used in the present invention as particularly useful polyimide raw materials are:
In the general formula (I), R ₂ is a group represented by the formula (VI): Wherein X ₂ is a direct bond, -CH _2- , -S -, - O -, - SO 2 -, - CO-, (Where Y ₂ is a direct bond, —S—, —O—, —SO ₂ —, —CO— or —CH ₂ —).] The tetracarboxylic dianhydride or pyromellitic dianhydride Things.

The phenolic solvent used in the method of the present invention includes phenol, m-cresol, o-cresol, p-cresol, cresylic acid, ethylphenol, isopropylphenol, tert-butylphenol, xylenol, chlorophenol, and dichlorophenol. , Phenylphenol and the like. These phenol solvents may be used alone or in combination of two or more.

In the present invention, triethylamine, tributylamine, tripentylamine, as an organic base to be coexistent when preparing a monomer solution or a polyamic acid solution,
N, N-dimethylaniline, N, N-diethylaniline, pyridine, α-picoline, β-picoline, γ-picoline, 2,
Examples thereof include 4-lutidine, 2,6-lutidine, quinoline, isoquinoline and the like, and preferably pyridine, γ-picoline and the like.

In addition, when producing a polyimide suitable for use in molding material applications, it is common to use a monoamine, a dicarboxylic anhydride, etc. as a polymer end capping agent at the time of polymerization, but these are used at the time of producing a polyamic acid solution. There is no problem even if they coexist.

Examples of the dicarboxylic anhydride used as the polymer end capping agent include phthalic anhydride, 2,3-benzophenone dicarboxylic anhydride, 3,4-benzophenone dicarboxylic anhydride, and 2,3-dicarboxyphenylphenyl. Ether anhydride, 3,4-dicarboxyphenyl phenyl ether anhydride, 2,3-biphenyl dicarboxylic anhydride, 3,4-biphenyl dicarboxylic anhydride, 2,3-dicarboxyphenyl phenyl sulfone anhydride, 3, 4-dicarboxyphenylphenylsulfone anhydride, 2,3-dicarboxyphenylphenylsulfide anhydride, 3,4-dicarboxyphenylphenylsulfide anhydride, 1,2-
Naphthalenedicarboxylic anhydride, 2,3-naphthalenedicarboxylic anhydride, 1,8-naphthalenedicarboxylic anhydride, 1,2-anthracenedicarboxylic anhydride, 2,3-anthracenedicarboxylic anhydride, 1,9- And anthracene dicarboxylic anhydride.

Further, as the monoamine compound, for example, aniline,
o-toluidine, m-toluidine, p-toluidine, 2,
3-xylidine, 2,4-xylidine, 2,5-xylidine,
2,6-xylidine, 3,4-xylidine, 3,5-xylidine, o-chloroaniline, m-chloroaniline, p-chloroaniline, o-bromoaniline, m-bromoaniline, p-bromoaniline, o- Nitroaniline, m-nitroaniline, p-nitroaniline, o-aminophenol, m-aminophenol, p-aminophenol,
o-anisidine, m-anisidine, p-anisidine, o
-Phenetidine, m-phenetidine, p-phenetidine, o-aminobenzaldehyde, m-aminobenzaldehyde, p-aminobenzaldehyde, o-aminobenzotrifluoride, m-aminobenzotrifluoride, p-aminobenzotrifluoride, o-aminobenzonitrile, m-aminobenzonitrile, p-aminobenzonitrile, 2-aminobiphenyl, 3-aminobiphenyl, 4-aminobiphenyl, 2-aminophenylphenyl ether, 3-aminophenylphenyl ether, 4-amino Phenylphenyl ether, 2-aminobenzophenone, 3-aminobenzophenone, 4-aminobenzophenyl, 2-aminophenylphenyl sulfide, 3-aminophenylphenyl sulfide, 4-aminophenylphenyls Fido, 2-aminophenylphenylsulfone, 3-aminophenylphenylsulfone, 4-aminophenylphenylsulfone, α-naphthylamine, β-naphthylamine, 1-amino-2-naphthol, 2-amino-1-naphthol, 4-amino -1
-Naphthol, 5-amino-1-naphthol, 5-amino-2-naphthol, 7-amino-2-naphthol, 8
-Amino-1-naphthol, 8-amino-2-naphthol, 1-aminoanthracene, 2-aminoanthracene, 9-aminoanthracene and the like.

Embodiments of the method of the present invention using the above various monomers and reaction reagents are as follows.

That is, the method according to the present invention, wherein the diamine compound and the tetracarboxylic dianhydride of the above (1) are separately dissolved in a phenolic solvent, and these solutions are mixed to initiate polymerization, Specifically, when a diamine compound represented by the general formula (I) is reacted with a tetracarboxylic dianhydride represented by the general formula (II) to produce a polyimide represented by the general formula (III), A monomer solution obtained by dissolving a diamine compound in a phenolic solvent and a monomer solution prepared by dissolving tetracarboxylic dianhydride in a phenolic solvent in the presence of an organic base are mixed,
This is a method of producing a corresponding polyimide by reacting at a temperature of 100 ° C. or higher.

In this method, the monomer solution concentration of the separately prepared monomer solution varies depending on the type of the monomer and the type of the phenolic solvent, and the solubility thereof is not particularly limited, but is usually 5 to 50% by weight. It is preferably 10 to 30% by weight from the viewpoint of workability and the like.

In this method, when preparing a monomer solution in which tetracarboxylic dianhydride is dissolved in a phenolic solvent, the amount of the organic base coexisting in the phenolic solvent depends on the type of the monomer used and the type of the phenolic solvent. Although different, it is usually from 10 to 1000 mol, preferably from 100 to 300 mol, per 100 mol of monomer.

Also, the mixing temperature of the monomer solution is usually 200 ° C. or less,
The temperature is preferably 100 ° C. or less, and heating may be performed in this temperature range when preparing the monomer solution.

The reaction temperature is 100 to 300 ° C, preferably 150 to 250 ° C.

 The reaction pressure is not particularly limited, and the reaction can be carried out at normal pressure.

The reaction time depends on the type of solvent and the reaction temperature,
Usually 4 to 24 hours is sufficient.

Of course, there is no problem even if an organic base is present in a separately prepared solution of the diamine compound in the phenolic solvent.

In the method (2) of the present invention, the diamine compound and the tetracarboxylic dianhydride are dissolved in a phenol solvent,
The method is characterized by reacting in the presence of an organic base, specifically, a diamine compound represented by the general formula (I) and a tetracarboxylic dianhydride represented by the general formula (II) The reaction is carried out in a phenolic solvent in the presence of an organic base to give a compound of the general formula (IV) (Wherein, R ₁ and R ₂ are the same as described above).
This is a method of producing a corresponding polyimide by reacting at a temperature of 0 ° C. or higher.

That is, in this method, a diamine compound and a tetracarboxylic dianhydride are directly added to a phenol solvent in which an organic base is present, and a polyamic acid solution containing a polyamic acid produced by the reaction is produced. The solution is heated to a temperature of 100 ° C. or higher to produce the corresponding polyimide.

When producing a polyamic acid solution by this method, the amount of the organic base coexisting in the phenolic solvent varies depending on the type of the monomer and the type of the phenolic solvent. ~ 1000
Moles, preferably 100-300 moles.

Further, the amount of the diamine compound and the tetracarboxylic dianhydride to be added to the phenolic solvent in which an organic base is coexisted is not particularly limited depending on the type of the monomer and the type of the phenolic solvent. The concentration of the monomer is usually from 5 to 50% by weight, preferably from 10 to 30% by weight in view of workability and the like, and the ratio of the diamine compound to the tetracarboxylic dianhydride is from 0.8 to 1.2, preferably from 0.9 to 0.9%. It is in the range of ~ 1.1.

Usually, the most common method is to charge an organic base and a diamine compound into a phenolic solvent and to add tetracarboxylic dianhydride in a divided manner.

The reaction temperature when producing a polyamic acid solution is usually 10
The temperature is 0 ° C. or lower, preferably 60 ° C. or lower.

The reaction pressure is not particularly limited, and the reaction can be carried out at normal pressure.

The reaction time depends on the type of monomer used, the type of solvent,
Depending on the reaction temperature, the reaction is usually carried out for a time sufficient to complete the formation of the polyamic acid. Usually 1 to 24 hours is sufficient.

The polyamic acid solution thus obtained is heated to a temperature of 100 ° C. or higher, and a corresponding polyimide is produced while removing reaction water generated due to imide cyclization.

The reaction temperature at the time of imide cyclization is 100 ° C. or higher, preferably 150 ° C. or higher. The reaction pressure is not particularly limited, and the reaction can be carried out at normal pressure. The reaction time varies depending on the type of the solvent and the reaction temperature, and usually 4 to 24 hours is sufficient.

〔effect〕

In the method of the present invention, a polyimide which should have excellent properties originally has a poor imidization rate due to its production method, contamination of a generated oligomer component, contamination of a multiphase mixture accompanied by defective removal of a residual solvent, and the like. An object of the present invention is to provide an improved method for producing a polyimide, which solves problems such as a decrease in heat resistance and a decrease in molding workability due to the above.

In the future, further high heat resistance, excellent mechanical properties and moldability are required for polyimide, but the method of the present invention is a method that can produce a polyimide that meets such requirements, and its use is This is highly expected.

In addition, the method of the present invention is a method for producing a polyimide that can thermally perform imide cyclization after polymerizing a polyamic acid in a phenolic solvent. It is also a very industrially superior method that can easily remove contaminants and the like that cause a decrease in the thermal stability of polyimide, and is industrially suitable for a large-scale production system.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

In addition, the physical property in an Example and a comparative example was measured by the following method.

Logarithmic viscosity (η); 0.50 g of polyimide powder was heated and dissolved in 100 ml of a mixed solvent of p-chlorophenol / phenol (weight ratio: 9/1) and measured at 35 ° C. Glass transition temperature (Tg); DSC (Shimadzu DT-40) Series DSC-4
1M) Example 1 42.29 g of pyromellitic dianhydride was placed in a vessel equipped with a stirrer, reflux condenser, water separator, nitrogen inlet tube and outlet.
(0.194 mol), 1.78 g (0.012 mol) of phthalic anhydride, 15.8 g (0.2 mol) of pyridine, and 195.6 g of m-cresol, and stirred under a nitrogen atmosphere with pyromellitic dianhydride and phthalic anhydride Is dissolved to prepare 255.5 g of a monomer solution A.

Next, 29.2 g (0.1 mol) of 1,3-bis (3-aminophenoxy) benzene and m-
79.54 g of cresol is charged and heated to 50 ° C. while stirring under a nitrogen atmosphere to dissolve 1,3-bis (3-aminophenoxy) benzene to prepare 108.8 g of a monomer solution B.

127.7 g of the monomer solution A was charged into the monomer solution B under a nitrogen atmosphere, and then heated to 202 ° C. while stirring. During this time, distillation of about 3.6 cc of water was confirmed. Further, the reaction was performed at 202 ° C. for 4 hours. afterwards,
The mixture was cooled to room temperature, discharged into about 1.5 methyl ethyl ketone, and filtered to obtain a pale yellow polyimide powder.

After washing the polyimide powder with methyl ethyl ketone, it was blow-dried at 200 ° C. for 6 hours under a nitrogen stream to obtain 46.
92 g (yield 98.5%) of polyimide powder was obtained.

The η of this polyimide powder was 0.51 dl / g, the Tg was 221 ° C., and the 1% weight loss temperature was 521 ° C.

Comparative Example 1 A reaction apparatus similar to that in Example 1 was charged with 29.2 g (0.1 mol) of 1,3-bis (3-aminophenoxy) benzene and 177.3 g of N-methyl-2-pyrrolidone, and a nitrogen atmosphere was added at room temperature. At the bottom, add 21.15 g (0.097 mol) of pyromellitic dianhydride in portions while paying attention to the rise in solution temperature.
Stir for 20 hours.

0.888 g (0.006 mol) of phthalic anhydride was added to this polyamic acid solution at room temperature under a nitrogen atmosphere, and the mixture was further stirred for 1 hour. Then, 7.9 g (0.1 mol) of pyridine and 40.8 g (0.4 mol) of acetic anhydride were added to the solution.
Then, after stirring at room temperature for 10 hours, the mixture was discharged into about 1.5 methyl ethyl ketone, and filtered to obtain a pale yellow polyimide powder.

After washing the polyimide powder with methyl ethyl ketone, it was blow-dried at 200 ° C. for 6 hours under a nitrogen stream to obtain 46.
68 g (98% yield) of polyimide powder was obtained.

The η of this polyimide powder was 0.50 dl / g, the Tg was 221 ° C., and the 1% weight loss temperature was as low as 479 ° C.

Comparative Example 2 In a reactor similar to that in Example 1, 29.2 g (0.1 mol) of 1,3-bis (3-aminophenoxy) benzene, 21.15 g (0.097 mol) of pyromellitic dianhydride and 0.888 of phthalic anhydride were used.
g (0.006 mol), pyridine 7.9 g (0.1 mol) and m-
177.3 g of cresol was charged and heated to 202 ° C. while stirring under a nitrogen atmosphere. During this time, distillation of about 3.6 cc of water was confirmed. After further reacting at 202 ° C. for 4 hours, the mixture was cooled to room temperature, discharged into about 1.5 methyl ethyl ketone, and filtered to obtain a pale yellow polyimide powder.

After washing the polyimide powder with methyl ethyl ketone, it was blow-dried at 200 ° C. for 6 hours under a nitrogen stream to obtain 46.
97 g (98.6% yield) of polyimide powder was obtained.

The η of this polyimide powder was 0.50 dl / g, the Tg was 221 ° C., and the 1% weight loss temperature was 498 ° C.

Example 2 In the same reactor as in Example 1, pyromellitic dianhydride (14.92 g, 0.068 mol) and phthalic anhydride 1.066 g (0.0072 g) were added.
Mol), 5.70 g (0.0726 mol) of pyridine and 68.9 g of m-cresol, and dissolving pyromellitic dianhydride and phthalic anhydride with stirring under a nitrogen atmosphere to prepare 90.57 g of a monomer solution C. I do.

Next, 4,4'-bis (3-
22.1 g (0.06 mol) of aminophenoxy) biphenyl and 60.0 g of m-cresol were charged and heated to 50 ° C. while stirring under a nitrogen atmosphere to dissolve 4,4′-bis (3-aminophenoxy) biphenyl. To prepare 82.11 g of monomer solution D.

The monomer solution D was added to the monomer solution C under a nitrogen atmosphere.
5.48 g was charged, and then heated to 202 ° C. while stirring. During this time, distillation of about 2.1 cc of water was confirmed. Further, after performing a reaction at 202 ° C. for 4 hours, the reaction solution was cooled to room temperature, discharged into about 1.5 methyl ethyl ketone, and filtered.
A yellow polyimide powder was obtained.

After washing this polyimide powder with methyl ethyl ketone, it was blow-dried at 200 ° C. for 6 hours under a nitrogen stream, and 32.
6 g (98% yield) of polyimide powder was obtained.

Η of this polyimide powder is 0.50dl / g, Tg is 252 ° C, 1%
The weight loss temperature was 540 ° C.

Example 3 62.15 g (0.193 mol) of 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 2.79 g (0.03 mol) of γ-picoline and 310.7 g of phenol were prepared in the same reactor as in Example 1. Was heated with stirring under a nitrogen atmosphere, and 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride was dissolved at 120 ° C. to prepare 375.6 g of a monomer solution E.

Next, 21.2 g (0.1 mol) of 3,3'-diaminobenzophenone and 57.6 g of phenol were placed in the same reactor as above.
And heated to 90 ° C. while stirring under a nitrogen atmosphere,
3,8.8 g of monomer solution F is prepared by dissolving 3,3'-diaminobenzophenone.

The monomer solution E1 was added to this monomer solution F under a nitrogen atmosphere.
87.8 g was charged, and then heated to 182 ° C. while stirring. During this time, distillation of about 3.6 cc of water was confirmed. Further, after performing the reaction at 182 ° C. for 4 hours, the mixture was cooled to about 50 ° C. and discharged into about 1.5 methyl ethyl ketone. Thereafter, the mixture was separated by filtration to obtain a pale yellow polyimide powder.

After washing this polyimide powder with methyl ethyl ketone, it was blow-dried at 200 ° C. for 6 hours under a nitrogen stream to 47.
2 g (97% yield) of polyimide powder was obtained.

The η of this polyimide powder was 0.50 dl / g, the Tg was 239 ° C., and the 1% weight loss temperature was 522 ° C.

Table 1 summarizes the results of Examples 1 to 3 and Comparative Examples 1 and 2.

Example 4 In the same reactor as in Example 1, 29.2 g (0.1 mol) of 1,3-bis (3-aminophenoxy) benzene and pyridine 1
5.8 (0.2 mol) and 185.6 g of m-cresol are charged, and 21.15 g (0.097 mol) of pyromellitic dianhydride are added in a nitrogen atmosphere while paying attention so that the solution temperature does not exceed 50 ° C. After stirring for 4 hours, phthalic anhydride 0.88
8 g (0.006 mol) was added, and stirring was further continued for 1 hour to obtain a pale yellow transparent polyamic acid solution. Thereafter, the temperature was raised to 202 ° C. while stirring. During this time, distillation of about 3.6 cc of water was confirmed. After further reacting at 202 ° C. for 4 hours, the reaction solution was cooled to room temperature, discharged into about 1.5 methyl ethyl ketone, and filtered to obtain a pale yellow polyimide powder.

After washing the polyimide powder with methyl ethyl ketone, it was blow-dried at 200 ° C. for 6 hours under a nitrogen stream to obtain 46.
92 g (98.5% yield) were obtained.

The η of this polyimide powder was 0.51 dl / g, the Tg was 221 ° C., and the 1% weight loss temperature in air was 523 ° C.

Example 5 A reaction apparatus similar to that of Example 1 was charged with 22.1 g (0.06 mol) of 4,4'-bis (3-aminophenoxy) biphenyl, 9.42 g (0.12 mol) of pyridine, and 128.7 g of m-cresol. , 12.36 g of pyromellitic dianhydride (0.
0567 mol) was added in portions, taking care that the solution temperature did not exceed 50 ° C., and stirring was continued for 4 hours. Then, 0.977 g (6.6 × 10 ⁻³ mol) of phthalic anhydride was added, and the mixture was further stirred for 1 hour. Thus, a pale yellow transparent viscous polyamic acid solution was obtained. Thereafter, the temperature was raised to 202 ° C. while stirring. During this time, about 2
Distillation of cc water was confirmed. After further reacting at 202 ° C. for 4 hours, the reaction solution was cooled to room temperature, discharged into about 1 methyl ethyl ketone, and filtered to obtain a yellow polyimide powder.

After washing this polyimide powder with methyl ethyl ketone, it was blow-dried at 200 ° C. for 6 hours under a nitrogen stream, and 32.
6 g (98% yield) of polyimide powder was obtained.

The η of this polyimide powder was 0.50 dl / g, the Tg was 252 ° C., and the 1% weight loss temperature was 542 ° C.

Comparative Example 3 In a reaction apparatus similar to that of Example 1, 22.1 g (0.06 mol) of 4,4'-bis (3-aminophenoxy) biphenyl and m-
128.7 g of cresol was charged, and 12.36 g (0.0567 mol) of pyromellitic dianhydride was added in portions under a nitrogen atmosphere, being careful not to exceed 50 ° C., and stirring was continued for 4 hours. , 0.977 g (6.6 × 10 ^-3 mol) of phthalic anhydride was added, and the mixture was further stirred for 1 hour.
No clear polyamic acid solution was obtained.

Example 6 In the same reaction apparatus as in Example 1, 2,3 g (0.1 mol) of 3,3'-diaminobenzophenone, 9.3 g of γ-picoline (0.1 mol)
Mol) and 200 g of phenol, and under nitrogen atmosphere
31.07 g (0.0965 mol) of 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride is decomposed and added with care so that the solution temperature does not exceed 50 ° C. After stirring for 4 hours, 1.036 g (7 × 10 ⁻³ mol) of phthalic anhydride was added, and the mixture was further stirred for 1 hour to obtain a pale orange transparent viscous polyamic acid solution.

Thereafter, the temperature was raised to 150 ° C. while stirring. During this time, distillation of about 3.5 cc of water was confirmed.

Further, after performing a reaction at 145 to 150 ° C. for 4 hours, the mixture was cooled to room temperature, discharged into about 1.5 methyl ethyl ketone, and filtered to obtain a pale yellow polyimide powder.

After washing this polyimide powder with methyl ethyl ketone, it was blow-dried at 200 ° C. for 6 hours under a nitrogen stream and 48.
2 g (97% yield) of polyimide powder was obtained.

The η of this polyimide powder was 0.50 dl / g, the Tg was 239 ° C., and the 1% weight loss temperature was 519 ° C.

Table 1 summarizes the results of Examples 1 to 6 and Comparative Examples 1 and 2.

Example 7 The polyimide particles obtained in Examples 1 to 6 and Comparative Examples 1 and 2 were used at a temperature of 400 ° C. and a pressure of 5 using a hot press.
A press sheet having a thickness of about 100 μm was prepared under the condition of 0 kg / cm ² .

The number of fish eyes and bubbles per 25 cm ^{2 of the} press sheet was measured, and the results are shown in Table 2.

The results in Table 2 show that the molded product obtained from the polyimide powder produced by the method of the present invention has little fisheye and foam and has good molding stability.

Continuation of front page (56) References JP-A-60-166325 (JP, A) JP-A-61-181832 (JP, A) JP-A-1-110530 (JP, A) JP-A-1-123830 (JP) , A) JP-B-46-11549 (JP, B1) JP-B-39-30060 (JP, B1)

Claims (2)

(57) [Claims] (1) General formula (I) H ₂ N—R ₁ —NH ₂ (I) wherein R ₁ is a group represented by the formula (V) (Wherein X ₁ is a direct bond, -CH _2- , -S -, - O -, - SO 2 -, - CO-, (Where Y ₁ is a direct bond, -S -, - O -, - SO 2 -, - CO-, A) a diamine compound represented by｝ which is a group represented by phenol, m-cresol, o-cresol, p-cresol, cresylic acid,
The diamine compound was dissolved in at least one phenolic solvent selected from the group consisting of ethylphenol, isopropylphenol, tert-butylphenol, xylenol, chlorophenol, dichlorophenol and phenylphenol at a concentration of 5 to 50% by weight. A solution and (b) pyromellitic dianhydride or the general formula (II) RIn the formula, R ₂ is the formula (VI) Wherein X ₂ is a direct bond, -CH _2- , -S -, - O -, - SO 2 -, - CO-, (Where Y ₂ is a direct bond, —S—, —O—, —SO ₂ —, —CO— or —CH ₂ —).] Anhydride is added to triethylamine, tributylamine, tripentylamine in an amount of 10 to 1000 mol based on 100 mol of the tetracarboxylic dianhydride.
N, N-dimethylaniline, N, N-diethylaniline, pyridine, α-picoline, β-picoline, γ-picoline, 2,
Dissolved in the phenolic solvent containing at least one organic base selected from the group consisting of 4-lutidine, 2,6-lutidine, quinoline and isoquinoline at a concentration of the tetracarboxylic dianhydride of 5 to 50% by weight. And (c) mixing and reacting at a temperature of 100 to 300 ° C. (Wherein, R ₁ and R ₂ are the same as described above). 2. (a) Formula (I) H ₂ N—R ₁ —NH ₂ (I) wherein R ₁ is a group represented by the formula (V) (Wherein X ₁ is a direct bond, -CH _2- , -S -, - O -, - SO 2 -, - CO-, (Where Y ₁ is a direct bond, -S -, - O -, - SO 2 -, - CO-, A) a diamine compound represented by｝ which is a group represented by (b) pyromellitic dianhydride or a general formula (II) RIn the formula, R ₂ is the formula (VI) Wherein X ₂ is a direct bond, -CH _2- , -S -, - O -, - SO 2 -, - CO-, (Where Y ₂ is a direct bond, —S—, —O—, —SO ₂ —, —CO— or —CH ₂ —).] Reacting with an anhydride in a phenolic solvent in the presence of an organic base, and (c) the organic base is reacted with the tetracarboxylic dianhydride 100
Triethylamine, tributylamine, tripentylamine, N, N-dimethylaniline, N, N-diethylaniline, pyridine, α-picoline, β-picoline, γ-picoline, 2, 4-lutidine, 2,6-lutidine, at least one selected from the group consisting of quinoline and isoquinoline, wherein the phenolic solvent is phenol, m-cresol, o-cresol, p-cresol, cresylic acid, ethylphenol, isopropyl At least one selected from the group consisting of phenol, tert-butylphenol, xylenol, chlorophenol and dichlorophenol, and (d) the obtained general formula (IV) (Wherein, R ₁ and R ₂ are the same as described above). A polyamic acid solution containing a polyamic acid comprising a repeating unit represented by the general formula (I) is prepared by reacting at a temperature of 100 to 300 ° C. Formula (III) (Wherein, R ₁ and R ₂ are the same as described above).