JP2001270945A - Method for manufacturing polyimide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a polyimide and/or its oligomer having good thermal stability by selecting a specific terminal blocking agent in an aqueous solvent. SOLUTION: A polyimide or its oligomer in the presence of a monoamine represented by the general formula: X-NH2 (wherein X- is a monovalent group) as a terminal blocking agent by the reaction of tetracarboxylic acid and/or its anhydride with a diamine 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 or an oligomer thereof having good thermal stability by selecting a specific terminal blocking agent in a method for producing a polyimide in an aqueous solvent.

[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, the physical properties of the polyimide obtained by this method cannot be said to be sufficient, and there has been a problem that various characteristics derived from the structure of the polyimide, such as thermal stability and melt fluidity, 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 method for producing a polyimide in an aqueous solvent, by appropriately selecting an endcapping agent to obtain various properties derived from the structure of the polyimide.
For example, deterioration of thermal stability, melt fluidity, etc. is minimized.

That is, the present invention provides the following [1] to [6]
Consists of

[1] When a tetracarboxylic acid and / or an anhydride thereof and a diamine are reacted in a reaction solvent containing 80 to 100% by weight of water, a general formula (1) is used as a terminal blocking agent. A) producing a polyimide and / or an oligomer thereof;

X—NH ₂ (1) (wherein, X— represents a monovalent group) [2] The amount of the monoamine used is based on 1 mole of the total of the used tetracarboxylic acid and its anhydride. 0.01
mol or more, the method for producing the polyimide and / or oligomer thereof according to [1].

[3] The method for producing a polyimide and / or an oligomer thereof according to [1] or [2], wherein the monoamine is aniline.

[4] When a tetracarboxylic acid and / or an anhydride thereof and a diamine are reacted in a reaction solvent containing 80 to 100% by weight or more of water,
After performing the reaction in the absence of the terminal blocking agent according to any one of [1] to [3], the reaction is performed in the presence of the terminal blocking agent according to any one of [1] to [3]. A method for producing polyimide and / or an oligomer thereof.

[5] A polyimide and / or an oligomer thereof obtained by the production method according to any one of [1] to [4].

[6] A polyimide obtained by heat-treating the polyimide or the oligomer thereof according to [5] at a temperature of 100 ° C. to 450 ° C.

[0017]

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 (2) or an oligomer thereof.

[0018]

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. 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, here, 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] The 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, and (C) a terminal blocking agent.

[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) 6, 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 and 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) alicyclic diamines such as 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.

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, which serve as crosslinking points, may be substituted with the above 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 needed.

[Tetracarboxylic acid component or its anhydride] The tetracarboxylic acid component or its anhydride used in the production of the polyimide of the present invention is not limited, but for example, pyromellitic dianhydride, 3 ,
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.

Further, for all of the above-mentioned tetracarboxylic acid components or 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 tetracarboxylic acid component or a part of its anhydride is replaced with hexacarboxylic trianhydrides and ring-opened products thereof, octacarboxylic acid tetraanhydrides and ring-opened products thereof. It may be replaced.

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

These tetracarboxylic acid components or their anhydrides can be used alone or in admixture, if necessary.

[Terminal Capping Agent] The essential terminal capping agent in the present invention is a monoamine represented by the general formula (1).

X-NH ₂ (1) (wherein, X- represents a monovalent group) Examples of the monoamine include 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-anisidine, m-anisidine, p-anisidine, o-phenetidine, m-phenetidine, p-phenetidine, o-aminophenol, m-aminophenol, p-aminophenol, o-amino Benzaldehyde, 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-amino E sulfonyl phenyl 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.

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

Further, these monoamines have a structure in which a part of the structure is an ethynyl group or a benzocyclobutene-
It may be substituted with a 4′-yl group, a vinyl group, an allyl group, a cyano group, an isocyanate group, a nitrilo group, an isopropenyl group, a vinylene group, a vinylidene group, an ethynylidene group, or the like.

Of these, aniline is preferably used.

The amount of the monoamine to be used is 0.0% with respect to 1 mol of the tetracarboxylic acid and its anhydride used.
It is preferably at least 1 mol, more preferably at least 0.01 mol and at most 10 mol, most preferably at least 0.02 mol and at most 1 mol.

In the present invention, dicarboxylic anhydrides and ring-opened products thereof can also be used as terminal blocking agents. Examples of the dicarboxylic anhydride and its ring-opened product include phthalic anhydride, 2,3-benzophenone dicarboxylic anhydride,
3,4-benzophenone dicarboxylic anhydride, 2,3-dicarboxyphenyl ether anhydride, 3,4-dicarboxyphenyl phenyl ether anhydride, 2,3-biphenyl dicarboxylic anhydride, 3,4-biphenyl dicarboxylic acid Anhydride, 2,3-dicarboxyphenylphenylsulfone 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-anthracene dicarboxylic anhydride and its ring-opened products.

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

Further, in these dicarboxylic anhydrides, a part of the structure thereof is an ethynyl group, a benzocyclobuten-4'-yl group, a vinyl group, an allyl group, a cyano group, an isocyanate group, a nitrile group which is a crosslinking point. And an isopropenyl group, a vinylene group, a vinylidene group, an ethynylidene group, or the like. .

[Solvent] Water is used as a 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. However, a method is preferred in which the diamine component and the tetracarboxylic acid component are dissolved or suspended in a solvent and heated to thermally dehydrate and imidize.

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

Preferably, when the tetracarboxylic acid and / or its anhydride and the diamine are reacted in the above-mentioned solvent, the reaction is carried out in the absence of a monoamine as a terminal blocking agent. A method of reacting in the presence of a monoamine is used.

[Polymerization / Imidation Conditions] The polymerization temperature, polymerization time and polymerization pressure are not particularly limited, and known conditions can be applied. That is, the reaction temperature is from 60 ° C to 400 ° C.
Before and after can be applied, preferably around 100 ° C to 300 ° C. The maximum temperature is limited by the boiling point of the solvent at the polymerization pressure. The reaction time varies depending on the type of solvent used and other reaction conditions.
5 to 24 hours. Furthermore, the reaction pressure is sufficient to be the vapor pressure of the solvent at the temperature.

The atmosphere is air, nitrogen, helium, neon,
Argon is used without any particular limitation, but is preferably replaced with an inert gas such as nitrogen or argon for the purpose of lowering the oxygen concentration.

[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.

[0068]

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.

The 5% weight loss temperature is determined by DT in air.
Using A-TG (Shimadzu DT-40 series, 40M)
Heating rate 10 ° C / min. Was measured.

EXAMPLES As raw materials, 28.06 g (0.096 mol) of 1,3-bis (4-aminophenoxy) benzene, 3,3 ′,
33.03 g of 4,4'-biphenyltetracarboxylic acid
(0.100 mol), 1.49 g of aniline (0.01
6 mol) to produce a polyimide.

Specifically, 28.06 g of 1,3-bis (4-aminophenoxy) benzene, 3,3 ', 4,4'-biphenyltetracarboxylic acid, and 33.80 g of 1,3-bis (4-aminophenoxy) benzene were placed in a pressure-tight container equipped with a stirrer. 03 g, distilled water 230 as a solvent
g. The temperature was raised to 220 ° C, and the reaction was performed at 220 ° C for 4 hours. Further, 1.49 g of aniline was charged, and 220 ° C.
For 2 hours. After cooling to room temperature, the resulting solid was crushed and filtered, washed with 200 g of distilled water, and washed with 200 g of distilled water.
Dry at 6 ° C. for 6 hours. The physical properties of the obtained yellow powder were as follows. The powder was melted at 400 ° C. for 5 minutes and quenched to obtain an amorphous product having a glass transition temperature of 198 ° C. The 5% weight loss temperature was 546 ° C.

Comparative Example A tan powder was obtained by synthesizing in the same manner as in Example except that aniline was not used. The physical properties of the obtained yellow powder were as follows. The powder was melted at 400 ° C. for 5 minutes and quenched to obtain an amorphous product having a glass transition temperature of 206 ° C. The 5% weight loss temperature was 518 ° C.

From these results, according to the method of the present invention,
It turns out that a polyimide having excellent heat stability can be produced.

[0075]

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.

Continued on the front page (72) Inventor Wataru Yamashita 30 Asamuta-cho, Omuta-shi, Fukuoka Mitsui Chemicals Co., Ltd. Terms (Reference) 4J043 PA01 PB23 QB15 QB26 QB31 RA35 SA06 TA14 TA22 UA041 UA051 UA091 UA121 UA131 UA132 UA141 UA151 UA152 UA161 UA171 UA262 UA761 UA762 UB011 UB021 UB122 UB132 UB121 UB122 UB122A YA06

Claims (6)

[Claims] When a tetracarboxylic acid and / or an anhydride thereof and a diamine are reacted in a reaction solvent containing 80 to 100% by weight of water, a general formula (1) is used as a terminal blocking agent. A method for producing a polyimide and / or an oligomer thereof, characterized in that a monoamine represented by the formula: X-NH ₂ (1) (wherein, X- represents a monovalent group) 2. The amount of the monoamine used is 0.01 mol or more based on 1 mol of the total of the tetracarboxylic acid and its anhydride used.
A method for producing the polyimide and / or oligomer thereof described above. 3. The method for producing a polyimide and / or an oligomer thereof according to claim 1, wherein the monoamine is aniline. 4. The method according to claim 1, wherein the reaction with tetracarboxylic acid and / or its anhydride and diamine is carried out in a reaction solvent containing 80 to 100% by weight or more of water.
After performing the reaction in the absence of the terminal blocking agent according to any one of claims 1 to 3, the reaction is performed in the presence of the terminal blocking agent according to any one of claims 1 to 3, A method for producing a polyimide and / or an oligomer thereof. 5. A polyimide and / or an oligomer thereof obtained by the production method according to claim 1. Description: 6. A polyimide obtained by subjecting the polyimide or its oligomer according to claim 5 to a heat treatment at 100 ° C. or higher and 450 ° C. or lower.