JP2001270943A - Method for manufacturing polyimide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method in which manufacturing of a polyimide is possible by a simple process in an aqueous solvent. SOLUTION: The method for manufacturing a polyimide and/or its oligomer comprises on of a tetracarboxylic acid and/or its anhydride and a diamine between 60 deg.C and 100 deg.C in a reaction solvent comprising 80-100 wt.% of water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing polyimide. More specifically, the present invention relates to a method for producing a polyimide in a water solvent, which enables polymerization by a simple process. Further, the present invention relates to a method for producing a polyimide and / or an oligomer thereof having few branches and good thermal stability.

[0002]

2. Description of the Related Art Conventionally, polyimide has been widely used in various fields as a molding material, a composite material, and an electric / electronic material because it has excellent mechanical properties and electrical properties in addition to its excellent heat resistance. Manufacturing methods have been widely studied.

[PRIOR ART] A method for producing a polyimide is, for example, a method in which polycondensation is carried out in a solid phase using a "salt monomer" composed of diamines and pyromellitic acids. (U.S. Patent 27108
No. 53) A method in which a polyamic acid is polymerized in an aprotic amide solvent such as N, N-dimethylacetamide, and the resulting polyamic acid solution is heated to thermally imidize the solvent while removing the solvent. (U.S. Pat. A method in which a dehydration imidization is performed chemically by reacting in the presence of a catalyst, mixed with a poor solvent to precipitate polyimide, and isolated by filtration and drying. (Tokuhei 5-516
No. 16) Diamines and tetracarboxylic dianhydrides are dissolved or suspended in a phenolic solvent such as cresol, immediately heated, thermally dehydrated and imidized, and mixed with a poor solvent. To precipitate polyimide, and then isolate by filtration and drying. (U.S. Pat.No. 5,288,843) A method in which a raw material is stirred under high pressure at a high temperature exceeding 100 ° C. in an aqueous solvent, and a product which is thermally imidized and precipitated is isolated (WO99 / 06470). ing.

[Problems of the prior art] However, from the viewpoints of molding workability and simplicity of the manufacturing process, in the case of the method (1), after forming a lump, a cutting, cutting, There is no other way than to apply a method of obtaining a molded body by performing mechanical processing such as polishing, and it is necessary to once isolate the “salt monomer” used in the manufacturing process, and the obtained “salt monomer” Because it is very unstable, it cannot be said to be a simple method.

In the case of the method (1), it is necessary to remove the solvent and water generated by imidization, and a film-shaped molded product can be obtained, but it is very difficult to obtain a large-sized molded product.

In the method of obtaining a polyimide powder by the above method, it is necessary to remove a large amount of a high boiling point solvent, and there is a disadvantage that the process is complicated and the cost is high.

Therefore, as shown in the following, polymerization with an aqueous solvent is being studied as a new method for producing polyimide. However, in the conventional method, it is necessary to carry out the polymerization under high pressure under the polymerization conditions exceeding 100 ° C., which is not preferable from the viewpoint of the process, and furthermore, the physical properties of the polyimide obtained by this method cannot be said to be sufficient. There is a problem that various characteristics such as thermal stability are deteriorated.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing polyimides having various structures, which has excellent physical properties derived from the structures, such as moldability, sliding properties, low water absorption, and electrical properties. An object of the present invention is to provide a method for obtaining polyimide and / or its oligomer by an easy and inexpensive process without deteriorating the thermal oxidation stability, radiation resistance, and the like.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a process for producing a polyimide in an aqueous solvent, which comprises selecting various reaction conditions to obtain various properties derived from the structure of the polyimide, such as heat stability and melt flow. It is intended to minimize the deterioration of sex and the like.

That is, the present invention provides the following (1) to (4)
Consists of

(1) In a reaction solvent containing 80 to 100% by weight of water, a tetracarboxylic acid and / or an anhydride thereof and a diamine are reacted at 60 ° C. or more and 100 ° C. or less. A method for producing a polyimide and / or an oligomer thereof.

(2) The method for producing a polyimide and / or an oligomer thereof according to (1), wherein the reaction solvent comprises 95% by weight or more of water.

(3) A polyimide and / or an oligomer thereof obtained by the production method according to (1) or (2).

(4) The polyimide according to (3) and / or
Or a polyimide obtained by heat-treating an oligomer thereof at a temperature of 100 ° C to 450 ° C.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Polyimide or oligomer thereof] The polyimide or oligomer thereof produced in the present invention is a polymer having a repeating structure represented by the general formula (1) or an oligomer thereof.

[0016]

Embedded image

(In the formula, Ar and R are each a group having an arbitrary structure.) The polyimide or its oligomer produced in the present invention is a known polyimide or its oligomer in general, and is a homopolymer or its oligomer. Or a copolymer or an oligomer thereof can be arbitrarily applied. Further, the present invention is also applicable to a case where another structure is included in a part of the main chain structure, or a case where a polymer or its oligomer terminal is blocked with a terminal blocking agent such as phthalic anhydride. Further, the structure such as a main chain, a side chain, or a terminal may have a structure such as a branch, a crosslinking factor, or a cyclic structure.

[Molecular weight of polyimide or oligomer thereof] Logarithmic viscosity is generally used as an index of the molecular weight of polyimide or oligomer thereof. The logarithmic viscosity of polyimide or oligomer thereof produced according to the present invention depends on the purpose. It can be controlled freely.

Although the specific molecular weight is not limited, the molecular weight of the polyimide is usually p-
Mixed solvent of chlorophenol and phenol (90:10
(Weight ratio), the logarithmic viscosity measured at 35 ° C. at a concentration of 0.5 g / dl is 0.30 or more and 5.0 or less, and the molecular weight of the polyimide oligomer is 0.05 to 0.1 logarithmic viscosity measured under the same conditions. It is less than 30.

[Raw Materials Used] Essential monomer raw materials used in the method for producing a polyimide of the present invention are (A) a diamine component, (B) a tetracarboxylic acid component or an anhydride thereof,
If necessary, (C) a terminal blocking agent can be used.

[Diamine Component] The diamine component used in the production of the polyimide of the present invention is not limited. For example, a) p-phenylenediamine and m-phenylenediamine having one benzene ring.

B) 3,3'- having two benzene rings
Diamino diphenyl ether, 3,4′-diamino diphenyl ether, 4,4′-diamino diphenyl ether, 3,3′-diamino diphenyl sulfide, 3,
4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3 '
-Diaminobenzophenone, 4,4'-diaminobenzophenone, 3,4'-diaminobenzophenone, 3,
3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2-di (3-aminophenyl) propane, 2,
2-di (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2,2-di (3-aminophenyl) -1,1,1,1
3,3,3-hexafluoropropane, 2,2-di (4
-Aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 2- (3-aminophenyl) -2-
(4-aminophenyl) -1,1,1,3,3,3-hexafluoropropane, 1,1-di (3-aminophenyl) -1-phenylethane, 1,1-di (4-aminophenyl ) -1-Phenylethane, 1- (3-aminophenyl) -1- (4-aminophenyl) -1-phenylethane.

C) 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (3
-Aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminobenzoyl) benzene, 1,3-bis (4-aminobenzoyl) benzene, 1,4-bis (3-aminobenzoyl) benzene, 1,4-bis (4-aminobenzoyl)
Benzene, 1,3-bis (3-amino-α, α-dimethylbenzyl) benzene, 1,3-bis (4-amino-
α, α-dimethylbenzyl) benzene, 1,4-bis (3-amino-α, α-dimethylbenzyl) benzene,
1,4-bis (4-amino-α, α-dimethylbenzyl) benzene, 1,3-bis (3-amino-α, α-ditrifluoromethylbenzyl) benzene, 1,3-bis (4-amino- α, α-ditrifluoromethylbenzyl) benzene, 1,4-bis (3-amino-α, α-ditrifluoromethylbenzyl) benzene, 1,4-bis (4-amino-α, α-ditrifluoromethylbenzyl) ) Benzene, 2,6-bis (3-aminophenoxy)
Benzonitrile, 2,6-bis (3-aminophenoxy) pyridine.

D) 4,4'- having 4 benzene rings
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 ] Sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, 2,2-bis [4- (3
-Aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [3- (3-aminophenoxy) phenyl] -1,1,1,3 , 3,3-hexafluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane.

E) 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (4-aminophenoxy) benzoyl] benzene having 5 benzene rings, 4-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,4-bis [4-
(4-aminophenoxy) benzoyl] benzene, 1,
3-bis [4- (3-aminophenoxy) -α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-
Aminophenoxy) -α, α-dimethylbenzyl] benzene, 1,4-bis [4- (3-aminophenoxy)-
α, α-dimethylbenzyl] benzene, 1,4-bis [4- (4-aminophenoxy) -α, α-dimethylbenzyl] benzene.

F) 4,4'- having 6 benzene rings
Bis [4- (4-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, 4,
4'-bis [4- (4-aminophenoxy) phenoxy] diphenylsulfone.

G) 3,3'-diamino-4,4'-diphenoxybenzophenone having an aromatic substituent,
3'-diamino-4,4'-dibiphenoxybenzophenone, 3,3'-diamino-4-phenoxybenzophenone, 3,3'-diamino-4-biphenoxybenzophenone.

H) having a spirobiindane ring,
6'-bis (3-aminophenoxy) 3,3,3 '
3, '-tetramethyl-1,1'-spirobiindane 6,6'-bis (4-aminophenoxy) 3,3
3, '3'-Tetramethyl-1,1'-spirobiindane.

I) 1,3 which are siloxane diamines
-Bis (3-aminopropyl) tetramethyldisiloxane, 1,3-bis (4-aminobutyl) tetramethyldisiloxane, α, ω-bis (3-aminopropyl) polydimethylsiloxane, α, ω-bis ( 3-aminobutyl) polydimethylsiloxane.

J) Bis (aminomethyl) ether, bis (2-aminoethyl) ether, bis (3-aminopropyl) ether, bis (2-aminomethoxy) ethyl] ether, bis [ 2- (2-aminoethoxy) ethyl] ether, bis [2- (3-aminoprotoxy) ethyl] ether,
1,2-bis (aminomethoxy) ethane, 1,2-bis (2-aminoethoxy) ethane, 1,2-bis [2-
(Aminomethoxy) ethoxy] ethane, 1,2-bis [2- (2-aminoethoxy) ethoxy] ethane, ethylene glycol bis (3-aminopropyl) ether,
Diethylene glycol bis (3-aminopropyl) ether, triethylene glycol bis (3-aminopropyl) ether.

K) methylenediamines such as ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,1
2-diaminododecane.

L) 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, 1,2-di (2
-Aminoethyl) cyclohexane, 1,3-di (2-aminoethyl) cyclohexane, 1,4-di (2-aminoethyl) cyclohexane, bis (4-aminocyclohexyl) methane, 2,6-bis (amino Methyl) bicyclo [2.2.1] heptane and 2,5-bis (aminomethyl) bicyclo [2.2.1] heptane are exemplified.

In addition, diamines in which some or all of the hydrogen atoms on the aromatic ring of the diamine are substituted with a substituent selected from a fluoro group, a methyl group, a methoxy group, a trifluoromethyl group, and a trifluoromethoxy group are also available. Can be used.

Further, depending on the purpose, an ethynyl group, a benzocyclobuten-4'-yl group, a vinyl group, an allyl group, a cyano group, an isocyanate group, a nitrilo group, and an isopropenyl group serving as a crosslinking point may be substituted with the above-mentioned diamine Even if a part or all of the hydrogen atoms on the aromatic ring are introduced as a substituent, they can be used. Furthermore, depending on the purpose, a vinylene group, a vinylidene group, and an ethynylidene group, which serve as crosslinking points, can be incorporated into the main chain skeleton instead of the substituent.

For the purpose of introducing a branch, a part of the diamine may be replaced with a triamine or a tetraamine.

Further, for the purpose of enhancing the solubility in water, a salt may be used.

These diamines can be used alone or in combination as necessary.

[Tetracarboxylic acid component or anhydride thereof] The tetracarboxylic acid component or anhydride thereof used in the production of the polyimide of the present invention is not limited. ,
3 ', 4,4'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'-benzophenonetetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl)
Ether dianhydride, bis (3,4-dicarboxyphenyl) sulfide dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 2,2-bis (3,4-
Dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,
3,3,3-hexafluoropropane dianhydride, 1,3
-Bis (3,4-dicarboxyphenoxy) benzene dianhydride, 1,4-bis (3,4-dicarboxyphenoxy) benzene dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) Biphenyl dianhydride, 2,2-bis [(3,4-dicarboxyphenoxy) phenyl] propane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8 -Naphthalenetetracarboxylic dianhydride, ethylenetetracarboxylic dianhydride, butanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, 2,2 ', 3,3'-benzophenonetetracarboxylic dianhydride Thing, 2,2 ', 3
3'-biphenyltetracarboxylic dianhydride, 2,2-
Bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl)-
1,1,1,3,3,3-hexafluoropropane dianhydride, bis (2,3-dicarboxyphenyl) ether dianhydride, bis (2,3-dicarboxyphenyl) sulfide dianhydride, bis (2,3-dicarboxyphenyl) sulfone dianhydride, 1,3-bis (2,3-dicarboxyphenoxy) benzene dianhydride, 1,4-bis (2,3-dicarboxyphenoxy) benzene dianhydride Products, and 1,2,5,6-naphthalenetetracarboxylic dianhydride, and their ring-opened products (including ring-opened products on only one side ... including monoanhydrides), etc., are not used alone or in combination. Can be.

For all of the above-mentioned tetracarboxylic acid components or their anhydrides, some or all of the hydrogen atoms on their aromatic rings may be replaced with fluoro, methyl, methoxy or trifluoromethyl groups. Or a tetracarboxylic acid component or an anhydride thereof substituted with a substituent selected from a trifluoromethoxy group.

Further, an ethynyl group, a benzocyclobuten-4'-yl group, a vinyl group, an allyl group, a cyano group, an isocyanate group, a nitrile group, and an isopropenyl group, which serve as crosslinking points, are added to the aromatic ring of the diamine. A part or all of the hydrogen atoms may be introduced as a substituent. Furthermore, a vinylene group, a vinylidene group, and an ethynylidene group, which are crosslinking points, may be incorporated not in the substituent but in the main chain skeleton, preferably within a range not to impair the moldability.

For the purpose of introducing a branch, a part of the tetracarboxylic acid component or its anhydride is replaced with hexacarboxylic trianhydride and its ring-opened product, octacarboxylic acid tetraanhydride and its ring-opened product. It may be replaced.

In order to enhance the solubility in water, a salt may be used.

These tetracarboxylic acid components or their anhydrides can be used alone or in admixture as needed.

[Terminal Capping Agent] The terminal capping agent used as required in the present invention is not limited. Typical are monoamine or dicarboxylic anhydrides and their ring-opened products.

As the monoamine, 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-xylysine, o-chloroaniline, m-chloroaniline, p-chloroaniline, o-bromoaniline,
m-bromoaniline, p-bromoaniline, o-nitroaniline, m-nitroaniline, p-nitroaniline,
o-anisidine, m-anisidine, p-anisidine, o
-Phenetidine, m-phenetidine, p-phenetidine, o-aminophenol, m-aminophenol, p
-Aminophenol, o-aminobenzaldehyde, m
-Aminobenzaldehyde, p-aminobenzaldehyde, o-aminobenzonitrile, m-aminobenzonitrile, p-aminobenzonitrile, 2-aminobiphenyl, 3-aminobiphenyl, 4-aminobiphenyl, 2
-Aminophenylphenyl ether, 3-aminophenylphenyl ether, 4-aminophenylphenyl ether, 2-aminobenzophenone, 3-aminobenzophenone, 4-aminobenzophenone, 2-aminophenylphenyl sulfide, 3-aminophenylphenyl sulfide, 4 -Aminophenylphenyl sulfide, 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, methylamine, dimethylamine, ethylamine, diethylamine, propylamine, dipropylamine, isopropylamine, diisopropylamine, butylamine, dibutylamine, isobutylamine, diisobutylamine, pentylamine, dipentylamine, benzylamine , Cyclopropylamine, cyclobutylamine, cyclopentylamine, cyclohexylamine and the like.

Examples of the dicarboxylic anhydride and its ring-opened product include phthalic anhydride, 2,3-benzophenone dicarboxylic anhydride, 3,4-benzophenone dicarboxylic anhydride, and 2,3-dicarboxyphenyl ether anhydride. Compound, 3,4-dicarboxyphenylphenyl ether anhydride, 2,3-biphenyldicarboxylic anhydride, 3,4-biphenyldicarboxylic anhydride, 2,3-dicarboxyphenylphenylsulfone anhydride, 3,4- Dicarboxyphenyl phenyl sulfone anhydride, 2,3-dicarboxyphenyl phenyl sulfide anhydride, 3,4-dicarboxyphenyl phenyl sulfide anhydride, 1,2-naphthalenedicarboxylic anhydride, 2,3-naphthalenedicarboxylic anhydride Anhydride, 1,8-naphthalenedicarboxylic anhydride, 1,2-anthracene dicarboxylic anhydride, 2,3-anthracene dicarboxylic anhydride, 1,9-anne Examples include tolcene dicarboxylic anhydride and ring-opened products thereof.

These monoamines or dicarboxylic anhydrides may have a part of their structure substituted by a group having no reactivity with amine or dicarboxylic anhydride.

Further, these monoamines or dicarboxylic anhydrides have a part of the structure in which an ethynyl group, a benzocyclobuten-4'-yl group, a vinyl group, an allyl group, a cyano group, an isocyanate group, which serves as a crosslinking point, It may be substituted with a nitrilo group, an isopropenyl group, a vinylene group, a vinylidene group, an ethynylidene group, or the like. .

[Solvent] Water is used as the solvent.

As the solvent, together with water, for example, alcohols, glycols, ethers, etc.
Solvents such as ethanol, dioxane, tetrahydrofuran, oligoethylene oxides, and ethylene glycol ethers can be used arbitrarily. Further, other additives such as inorganic acids, inorganic bases, salts of inorganic cations and surfactants may be contained.

The amount of these solvents other than water and other additives must not exceed 20% by weight. The amount is preferably less than 10% by weight, more preferably 5% by weight.
And most preferably substantially free of these.

[Polymerization / Imidation Method] In the method of the present invention, the polymerization / imidization method is not limited as long as the above-mentioned solvent is used, but the diamine component / tetracarboxylic acid is dissolved or suspended in the solvent. It is preferable to perform a thermal dehydration imidization by heating in a turbid state.

At this time, the order and timing of charging the monomers can be arbitrarily selected.

[Polymerization / Imidation Conditions] The polymerization temperature is 60 ° C.
At least 100 ° C. and preferably at least 80 ° C.
° C or lower, more preferably 90 ° C or higher and 100 ° C or lower, and most preferably the boiling point of water at normal pressure (about 1 ° C).
00 ° C). The polymerization time is not particularly limited, and known conditions can be applied. That is, the reaction time varies depending on the type of the solvent used and other reaction conditions, but is generally 0.5 to 24 hours. Normal reaction pressure is sufficient.

The atmosphere is air, nitrogen, helium, neon,
Argon is used without any particular limitation, but nitrogen or argon, which is an inert gas, is preferably selected.

[Polymerization State] In the method of the present invention, the reaction state is not limited as long as the above-mentioned mixed solvent is used. However, in the present invention, the polymerization state at the end of thermal imidization in the mixed solvent is preferably It is a slurry.

[Removal] The polyimide can be removed from the reaction system by a known method.

A general removal method is filtration, and a known method can be applied to the filtration method. Further, a method of directly distilling the solvent from the slurry state is also used.

In the method of the present invention, the polyimide obtained by this operation is usually in the form of a powder, and this form is preferable for removing the solvent and for use in various applications.

[Solvent Removal / Heat Treatment] As a method of solvent removal / heat treatment, various known methods can be applied mutatis mutandis. Generally, it is dried at 100 to 400 ° C. More specifically, it is dried at 100 to 400 ° C. in an oven to remove the solvent.
Alternatively, a method can be used in which the wet cake is directly charged into an extruder or the like, and the solvent is removed together with deaeration in a molten state.

[0061]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto.

The glass transition temperature in the examples was measured by DSC (Shimadzu DT-40 series, DSC-41M) at a heating rate of 10 ° C./min. Was measured.

EXAMPLE As a raw material, 3,3'-diaminodiphenyl ether 2
0.02 g (0.100 mol), pyromellitic acid 2
Polyimide was produced using 5.42 g (0.100 mol).

Specifically, 227 g of the above monomer and distilled water were charged into a vessel equipped with a stirrer, a reflux condenser, and a nitrogen inlet tube. Heat to 100 ° C,
The reaction was performed at 00 ° C. for 12 hours. The obtained solid was separated by filtration, washed with 200 g of distilled water, and dried at 200 ° C. for 6 hours.

The obtained solid was a yellow powder. The physical properties of the yellow powder were as follows. The powder was melted at 440 ° C. for 5 minutes, and quenched to obtain an amorphous product having a glass transition temperature of 305 ° C. The IR of the powder was measured.
An absorption at 780 cm ^-1 (peak 1 in the figure) was observed. FIG. 1 shows an enlarged view of a main part of the measurement results. In FIG. 1, the horizontal axis indicates the wave number (cm ^-1 ), the vertical axis indicates the transmittance (%), and 1 to 13 indicate the positions of the peak tops.

[0066]

As described above, according to the present invention,
In the method for producing polyimide of various structures, excellent physical properties derived from the structure, for example, moldability, sliding properties,
Polyimide and / or its oligomers can be obtained by an easy and inexpensive process without impairing low water absorption, electrical properties, thermal oxidation stability, radiation resistance and the like.

[Brief description of the drawings]

FIG. 1 is an enlarged view showing a measurement result of an IR spectrum of an example.

[Explanation of symbols]

 1-13 Position of each peak top

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Wataru Yamashita, Inventor Wataru Yamashita 30, Omuta-shi, Fukuoka Prefecture Mitsui Chemicals Co., Ltd. In-house F-term (reference) 4J043 PA02 RA35 TA14 TA22 TB01 UA091 UA121 UA122 UA131 UA141 UA151 UA161 UA171 UB011 UB021 UB061 UB121 UB151 UB281 UB301 UB401 VA011 VA021 VA051 VA061 YA06 ZB51

Claims (4)

[Claims] 1. A polyimide characterized by reacting tetracarboxylic acid and / or its anhydride and diamine at 60 ° C. to 100 ° C. in a reaction solvent containing 80 to 100% by weight of water. And / or a method for producing an oligomer thereof. 2. The method for producing a polyimide and / or an oligomer thereof according to claim 1, wherein the reaction solvent comprises 95% by weight or more of water. 3. A polyimide and / or an oligomer thereof obtained by the production method according to claim 1. 4. A polyimide obtained by heat treating the polyimide and / or oligomer thereof according to claim 3 at a temperature of 100 ° C. or more and 450 ° C. or less.