JPH11292967A - Linear polyamic acid, linear polyimide and thermosetting polyimide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a linear polyimide capable of exhibiting further excellent heat resistance while keeping characteristics of this resin itself and useful for structural members, or the like, of composite materials, or the like by introducing a specific sulfur-containing group into a recurring unit and blocking the molecular terminal with maleic acid-based anhydride. SOLUTION: This linear polyimide is represented by formula I [P1 is a group of formula II or formula III; S1 is a group of formula IV or a group of formula V; (m) is 100-1 recurring unit (mol.%) and (n) is 0-99 recurring unit (mol.%); (l) is a polymerization degree of 1-100]. The linear polyimide is obtained by reacting e.g. bis [4-(3-aminophenoxy)phenyl]sulfone as a diamine component with pyromellitic acid dianhydride as a tetracarboxylic acid dianhydrode or a mixture of pyromellitic acid dianhydrode with 3,3',4,4'- diphenyltetracarboxylic acid diahydride in the presence of maleic anhydride which is a molecular terminal blocking agent to afford a linear polyamic acid having 0.05-1.0 dl/g logarithmic viscosity and imidizing the linear polyamic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a novel linear polyamic acid or a linear polyimide, a thermosetting polyimide obtained by heat-treating the same, and a thermosetting polyimide containing the thermosetting polyimide and a fibrous reinforcing material. Composite material.

The thermosetting polyimide of the present invention has excellent physical properties of thermoplastic polyimide and further excellent heat resistance. A composite material containing a polyamic acid and a fibrous reinforcing material is heat-treated and cured to provide a composite material having extremely excellent heat resistance.

[0003]

2. Description of the Related Art Conventionally, polyimide has excellent properties in mechanical properties, chemical resistance, flame retardancy, electrical properties, etc. in addition to its excellent heat resistance.
It is widely used in the fields of composite materials, electric / electronic parts and the like. For example, a typical polyimide is represented by the formula (A)

Embedded image (Manufactured by DuPont, trade name; Kapton, Vespel) is known, but this polyimide is non-thermoplastic and has inconvenient molding processability due to insolubility and infusibility.

As an amorphous thermoplastic polyimide having improved moldability, a compound represented by the formula (B)

Embedded image (Product name: Ultem, manufactured by General Electric)
(U.S. Pat. No. 3,847,867). However, this polyimide has a glass transition temperature of 215.
° C, and cannot be said to have sufficient heat resistance. The formula (C)

Embedded image Can be melt-molded while maintaining the inherent heat resistance, solvent resistance, mechanical properties, and the like of the polyimide (US Pat. No. 5,043,419). However, since this polyimide is thermoplastic, it has a glass transition temperature (250 ° C.). Above that temperature, it is practically unusable because it is accompanied by deformation, softening, and significant property deterioration.

On the other hand, as a thermosetting polyimide, the formula (D)

Embedded image Is known (manufactured by Rhone Poulin Co., Ltd., trade name; Kelimide-601, FD Dar)
more, National SAMPE Symp
osium, p. 693, Volume 19 (197
4)). Since this polyimide is thermosetting, it is less likely to deform and soften than thermoplastic polyimide and can be used at high temperatures, but this polyimide has poor mechanical properties.
Still another thermosetting polyimide has the formula (E)

Embedded image US Pat. No. 5,412,066 discloses a thermosetting polyimide obtained by heat-treating a polyimide oligomer having a carbon-carbon triple bond at a molecular terminal as represented by the following formula. Although this polyimide is thermosetting, its glass transition temperature is 230-250 even after heat treatment.
° C, which does not have sufficient heat resistance as a thermosetting polyimide, and there is an upper limit to the operating temperature at high temperatures.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyimide having extremely excellent heat resistance, that is, having excellent physical properties of thermoplastic polyimide, and further improving the heat resistance of these thermoplastic polyimides. Is to provide a thermosetting polyimide. Another object is to provide a linear polyimide or a linear polyamic acid which is capable of providing a thermosetting polyimide having excellent heat resistance by being thermally cured by being cured with a reactive molecular terminal sealing agent at the terminal of the molecule. It is to be. Still another object is to include a thermosetting polyimide and a fiber reinforcement obtained by heat-treating a composite material containing these linear polyimide or linear polyamic acid and a fibrous reinforcement, heat resistance and It is to provide a composite material having excellent mechanical properties.

[0007]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have a specific repeating unit, and further have a carbon-carbon double bond at the molecular terminal. A thermosetting polyimide obtained by heat-treating a linear polyimide or linear polyamic acid sealed with a maleic acid-based dicarboxylic anhydride has a corresponding thermoplastic polyimide or polyimide copolymer having this specific repeating unit. The inventor has found that it has the original physical properties of the union and is extremely excellent in heat resistance and mechanical properties, and has completed the present invention.

That is, the present invention provides the following formula (1)

Embedded image (Where P1 is the following formula (a) or formula (b)

Embedded image And S1 represents the formula (c) or the formula (d)

Embedded image Wherein m and n represent mol% of each repeating unit, and m is 100 to
1 mol%, n is 0 to 99 mol%, and there is no regularity or regularity between the repeating units. 1 represents the degree of polymerization, and is an integer of 1 to 100. A) a linear polyimide represented by the formula (2),

Embedded image [Wherein P2 is the formula (e) or the formula (f)

Embedded image And S2 represents the formula (g) or the formula (h)

Embedded image At least one of monovalent groups represented by m, n,
And l are the same as in the case of the formula (1)], and the above-mentioned linear polyimide and / or
Alternatively, it is a thermosetting polyimide obtained by heating and curing a linear polyamic acid. Furthermore, a composite material containing the above-mentioned linear polyimide and / or linear polyamic acid and a fibrous reinforcing material, and a thermosetting polyimide obtained by heating this composite material and a fiber reinforcing material It is a composite material.

The above-mentioned linear polyimide and / or linear polyamic acid is used as a diamine component in the following formula (a):
1)

Embedded image Bis [4- (3-aminophenoxy) phenyl] sulfone alone or of the formula (1-2)

Embedded image 4,4′-diaminodiphenyl ether of formula (1-1) wherein the diamine component is bis [4- (3-aminophenoxy) phenyl] sulfone of the formula (1-1) When used alone, the formula (1-3)

Embedded image Of pyromellitic dianhydride alone or of the formula (1-4)

Embedded image And 3,3 ′, 4,4′-diphenyltetracarboxylic dianhydride.
Bis [4- (3-aminophenoxy) phenyl] of 1)
When a mixture of sulfone and 4,4′-diaminodiphenyl ether of the formula (1-2) is used, pyromellitic dianhydride of the formula (1-3) is used and (c) a molecular terminal blocking agent. Formula (1-5)

Embedded image And reacting in the presence of maleic anhydride represented by the formula:

In the present invention, preferred linear polyimides or linear polyamic acids include the following. That is, equation (3)

Embedded image [Where S3 is the formula (i) or the formula (j)]

Embedded image At least one of monovalent groups represented by
Represents mol% of each repeating unit, and m represents 100 to 7
0 mol%, n is 0 to 30 mol%, and there is no regularity or regularity between the repeating units. 1 represents the degree of polymerization, and is an integer of 1 to 100. A) a linear polyimide represented by the formula (1)

Embedded image [Where S4 is the following equation (k) or equation (l)]

Embedded image Wherein m, n and l are the same as in the case of the formula (3), and a linear polyamic acid of the formula (5)

Embedded image [Wherein, m and n represent mol% of each repeating unit, m is 100 to 70 mol%, n is 0 to 30 mol%, and the regularity and regularity between the repeating units are Absent.
1 represents the degree of polymerization, and is an integer of 1 to 100. Formula (6) which is a linear polyimide or a precursor thereof represented by the following formula:

Embedded image [Wherein m, n and l are the same as in the case of the formula (5)].

In each of the above formulas, a linear polyimide and a linear polyamic acid having a composition ratio of m: n of 100 mol%: 0 mol%, that is, a formula (7)

Embedded image [In the formula, 1 represents the degree of polymerization, and is an integer of 1 to 100. Linear polyimide represented by the formula (7-1)

Embedded image Represented by the formula (7-a) and the formula (7-b)

Embedded image And a precursor thereof and a formula (8)

Embedded image Is a linear polyamic acid represented by

The linear polyimide of the present invention has a logarithmic viscosity of a linear polyamic acid as a precursor thereof (measured at 35 ° C. in an N, N-dimethylacetamide solvent at a concentration of 0.5 g / dl; hereinafter, measured under the same conditions). Is 0.05 to 1.0 dl / g
It is. Further, the present invention is a thermosetting polyimide obtained by heat-treating these preferred linear polyimides and / or linear polyamic acids, and contains the linear polyimides and / or linear polyamic acids and a fiber reinforcing material. A composite material comprising a composite material and a thermosetting polyimide obtained by heat-treating the composite material and a fiber reinforcing material. Thermoplastic polyimides are excellent in various properties, but have a problem in applicability at a glass transition temperature or higher. On the other hand, thermosetting polyimide is extremely excellent in heat resistance and can be applied at a high temperature, but has a problem in mechanical properties (toughness). The linear polyimide and / or linear polyamic acid of the present invention provides a thermosetting polyimide which solves the above problems. That is, the thermosetting polyimide of the present invention improves the heat resistance of the thermoplastic polyimide, has the original properties, and improves the mechanical properties of the thermosetting polyimide. Therefore, various composite materials,
For example, a novel material can be provided as a matrix for an aircraft.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The linear polyimide and the linear polyamic acid of the present invention are defined as follows in the present specification. That is, for example, a linear polyimide is obtained by the formula (1)

Embedded image Wherein P1, S1, m, n and l in the formula are defined as above. This linear polyimide has the formula (M)

Embedded image A repeating unit represented by the formula (N) or the formula (O) defined by P1 in the formula (1)

Embedded image Wherein the composition ratio of the repeating unit of the formula (M) to the repeating unit of the formula (N) or (O) is represented by a composition ratio represented by m: n in the formula (1),
It is shown in mol%. That is, the composition ratio of the repeating unit in the formula (1) is such that the repeating unit (M) is 100 to 1 mol%, and the repeating unit (N) or (O) is 0 to 99 mol%.
Is shown. In addition, one of the molecular terminals is represented by the formula (P)

Embedded image And the other is a formula (Q) or a formula (R) represented by S1 in the formula (1).

Embedded image Represents a linear polyimide which is at least one of the monovalent groups represented by.

Other formulas (3) and (5) of the present invention
Linear polyimide represented by (7) and formulas (4), (6),
In the same manner as described above, the linear polyamic acid represented by (8) represents a repeating unit, a composition ratio of the repeating unit, and a linear polyimide and a linear polyamic acid having a molecular terminal group, respectively. Further, the linear polyimide and the linear polyamic acid in the present specification are composed of a single repeating unit of the formula (M) [the formulas (7) and (8) are independently defined], and the formula (M) Is a linear polyimide which is composed of two kinds of repeating units having a repeating unit of the formula (N) or (O), and in which these repeating units are randomly arranged, or a linear polyamide which is a precursor thereof. It contains acids.

The linear polyamic acid or linear polyimide of the present invention is produced by the following method. The essential diamine component and tetracarboxylic dianhydride component are represented by the formula (1)
-1) bis [4- (3-aminophenoxy) phenyl] sulfone and pyromellitic dianhydride of the formula (1-3), and a diamine component or a tetracarboxylic acid used in combination with these. 4,4'- dianhydride
Diaminodiphenyl ether or 3,3 ', 4,4'
-Biphenyltetracarboxylic dianhydride. Therefore, bis [4- (3-aminophenoxy) phenyl] sulfone and pyromellitic dianhydride are essential monomers for producing the linear polyimide or linear polyamic acid of the present invention, or these essential monomers are used. On 4,
4'-diaminodiphenyl ether or 3,3 ',
A mixture of 4,4'-biphenyltetracarboxylic dianhydride is used.

Specifically, bis [4- (3-aminophenoxy) phenyl] sulfone and pyromellit are required to produce the linear polyimide of the formula (7) or the linear polyamic acid of the formula (8). Using acid dianhydride and 4,4′-diaminodiphenyl ether, the compound represented by the formula (3)
To produce a linear polyimide having two types of repeating units of the formulas (5) and (5) and a linear polyamic acid having two types of the repeating units of the formulas (4) and (6), bis [4
-(3-Aminophenoxy) phenyl] sulfone and pyromellitic dianhydride and 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride are used.

In the linear polyimide and linear polyamic acid of the present invention, the above-mentioned aromatic diamine is used as an essential monomer, but other aromatic diamines can be further added as long as the good physical properties are not impaired. For example, diamines that can be added include, for example, 4,4′-bis (3-aminophenoxy) biphenyl, bis [4-
(3-aminophenoxy) phenyl] ketone, bis [4
-(3-aminophenoxy) phenyl] sulfide,
2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane , M-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, 3,3′-
Diamino diphenyl ether, 3,4′-diamino diphenyl ether, 4,4′-diamino diphenyl ether, 3,3′-diamino diphenyl sulfide, 3,
3′-diaminodiphenylsulfoxide, 3,4′-diaminodiphenylsulfoxide, 4,4′-diaminodiphenylsulfoxide, 3,3′-diaminodiphenylsulfone, 3,4′-diaminodiphenylsulfone,
4,4′-diaminodiphenyl sulfone, 3,3′-diaminobenzophenone, 3,4′-diaminobenzophenone 4,4′-diaminobenzophenone, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4, 4'-diaminodiphenylmethane, bis [4- (4-aminophenoxy) phenyl] methane,
1,1-bis [4- (4-aminophenoxy) phenyl] ethane, 1,2-bis [4- (4-aminophenoxy) phenyl] ethane, 1,1-bis [4- (4-aminophenoxy) Phenyl] propane, 1,2-bis [4
-(4-aminophenoxy) phenyl] propane, 1,
3-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy)
Phenyl] propane, 1,1-bis [4- (4-aminophenoxy) phenyl] butane, 1,3-bis [4-
(4-aminophenoxy) phenyl] butane, 1,4-
Bis [4- (4-aminophenoxy) phenyl] butane, 2,2-bis [4- (4-aminophenoxy) phenyl] butane, 2,3-bis [4- (4-aminophenoxy) phenyl] butane, 2- [4- (4-aminophenoxy) phenyl] -2- [4- (4-aminophenoxy) -3-methylphenyl] propane, 2,2-bis [4- (4-aminophenoxy) -3- Methylphenyl] propane, 2- [4- (4-aminophenoxy) phenyl] -2- [4- (4-aminophenoxy) -3,
5-dimethylphenyl] propane, 2,2-bis [4-
(4-aminophenoxy) -3,5-dimethylphenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, , 3-bis (4-aminophenoxy) benzene, 1,4-bis (3-aminophenoxy)
Benzene, 1,3-bis (3-aminophenoxy) benzene 1,4-bis (4-aminophenoxy) benzene,
4,4′-bis (4-aminophenoxy) biphenyl,
Bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfoxide, bis [4- (4-amino) Phenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, 1,3-bis [4-
(4-aminophenoxy) benzoyl] benzene, 1,
3-bis [4- (3-aminophenoxy) benzoyl]
Benzene, 1,4-bis [4- (3-aminophenoxy) benzoyl] benzene, 4,4'-bis (3-aminophenoxy) benzoyl] benzene, 1,1-bis [4- (3-aminophenoxy) Phenyl] propane,
1,3-bis [4- (3-aminophenoxy) phenyl] propane, 3,4′-diaminodiphenylsulfide, 2,2-bis [3- (3-aminophenoxy) phenyl] -1,1,1, 3,3,3-hexafluoropropane, bis [4- (3-aminophenoxy) phenyl]
Methane, 1,1-bis [4- (3-aminophenoxy)
Phenyl] ethane, 1,2-bis [4- (3-aminophenoxy) phenyl] ethane, 2,2-bis [4- (3
-Aminophenoxy) phenyl] sulfoxide, 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] diphenyl sulfone , Bis [4- @ 4- (4
-Aminophenoxy) phenoxydiphenyl] sulfone, 1,4-bis [4- (4-aminophenoxy) phenoxy-α, α-dimethylbenzyl] benzene, 1,3
-Bis [4- (4-aminophenoxy) phenoxy-
α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-trifluoromethylphenoxy) -α, α-dimethylbenzyl] benzene, 1,3-
Bis [4- (4-amino-6-fluorophenoxy)-
α, α-dimethylbenzyl] benzene, 1,3-bis [4- (4-amino-6-methylphenoxy) -α, α
-Dimethylbenzyl] benzene, 1,3-bis [4-
(4-amino-6-cyanophenoxy) -α, α-dimethylbenzyl] benzene, 3,3′-diamino-4,
4'-diphenoxybenzophenone, 4,4'-diamino-5,5'-diphenoxybenzophenone, 3,4 '
-Diamino-4,5'-diphenoxybenzophenone,
3,3′-diamino-4-phenoxybenzophenone,
4,4′-diamino-5-phenoxybenzophenone,
3,4′-diamino-4-phenoxybenzophenone,
3,4'-diamino-5'-phenoxybenzophenone, 3,3'-diamino-4,4'-dibiphenoxybenzophenone, 4,4'-diamino-5,5'-dibiphenoxybenzophenone, 3,4'- Diamino-4,
5'-dibiphenoxybenzophenone, 3,3'-diamino-4-biphenoxybenzophenone, 4,4'-diamino-5-biphenoxybenzophenone, 3,4'-
Diamino-4-biphenoxybenzophenone, 3,4 ′
-Diamino-5'-biphenoxybenzophenone, 1,
3-bis (3-amino-4-phenoxybenzoyl) benzene, 1,4-bis (3-amino-4-phenoxybenzoyl) benzene, 1,3-bis (4-amino-5-
Phenoxybenzoyl) benzene, 1,4-bis (4-
Amino-5-phenoxybenzoyl) benzene, 1,3
-Bis (3-amino-4-biphenoxybenzoyl) benzene, 1,4-bis (3-amino-4-biphenoxybenzoyl) benzene, 1,3-bis (4-amino-5
-Biphenoxybenzoyl) benzene, 1,4-bis (4-amino-5-biphenoxybenzoyl) benzene, 2,6-bis [4- (4-amino-α, α-dimethylbenzyl) phenoxy] benzonitrile, And part or all of the hydrogen atoms on the aromatic ring of the aromatic diamine is a halogen atom, an alkyl group or an alkoxy group having 1 to 3 carbon atoms, a cyano group, or a part or all of the hydrogen atoms of an alkyl group or an alkoxy group. And an aromatic diamine substituted with a halogenated alkyl group having 1 to 3 carbon atoms or an alkoxy group substituted with a halogen atom. Further, these aromatic diamines may be used alone or in combination of two or more.

Similarly, another aromatic tetracarboxylic dianhydride can be further added. As the aromatic tetracarboxylic dianhydride that can be added, for example,
2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, ethylenetetracarboxylic dianhydride, butanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, 3,3 ′, 4 , 4′-benzophenonetetracarboxylic dianhydride, 2,2 ′, 3,3′-benzophenonetetracarboxylic dianhydride, 2,2 ′,
3,3′-biphenyltetracarboxylic dianhydride, 2,
2-bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) -1,1,1,3,3,3-trifluoromethylpropane dianhydride , Bis (2,3-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis (2,3-dicarboxyphenyl) sulfone dianhydride, bis (3 , 4-Dicarboxyphenyl) sulfone dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-
Dicarboxyphenyl) methane dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride,
1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, 1,2-bis (3,4-dicarboxyphenyl) ethane dianhydride, 1,3-bis (2,3-dicarboxy) Phenoxybenzene dianhydride, 1,3-bis (3,
4-dicarboxyphenoxy) benzene dianhydride, 1,
4-bis (2,3-dicarboxyphenoxy) benzene dianhydride, 1,4-bis (3,4-dicarboxyphenoxy) benzene dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8
-Phenanthrene tetracarboxylic dianhydride, and some or all of the hydrogen atoms on the aromatic ring of the aromatic tetracarboxylic dianhydride are substituted with halogen atoms, halogenated alkyl groups having 1 to 3 carbon atoms or alkoxy groups. Aromatic tetracarboxylic dianhydride and the like. These may be used alone or in combination of two or more.

In the production of the linear polyimide or the linear polyamic acid of the present invention, the amounts of the aromatic diamine component and the aromatic tetracarboxylic dianhydride component are used per mole of the aromatic diamine component. The anhydride component has a molar ratio of 0.1 to 1.0. If it is less than 0.1 mol, a linear polyimide for obtaining a thermosetting polyimide having good physical properties cannot be obtained. Preferably 0.5 to 1.
The molar ratio is 0, more preferably 0.7 to 1.0. When two kinds of diamines of bis [4- (3-aminophenoxy) phenyl] sulfone and 4,4′-diaminodiphenyl ether are used as the diamine component, the amount of these diamines used is bis [4- (3- [Aminophenoxy) phenyl] sulfone: 100 to 1 mol% of 4,4'-diaminodiphenylether: 0 to 99 mol%, preferably 100 to 70 mol%: 0 to 30 mol%
And two aromatic tetracarboxylic dianhydrides of pyrimellitic dianhydride and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride as tetracarboxylic dianhydride components When used, these aromatic tetracarboxylic dianhydrides are used in an amount of 100-1 mol% of pyromellitic dianhydride: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride: 0 to 99 mol%, preferably 100 to 50 mol%: 0 to 50 mol%. In order to seal the molecular end of the linear polyimide or linear polyamic acid of the present invention, the compound represented by the formula (1-5)

Embedded image Is used.

The amount of maleic anhydride used is 0.001 to 1.0 mole ratio per mole of the aromatic diamine component.
If the amount is less than 0.001 mol, the crosslinking reaction does not sufficiently proceed even if the obtained linear polyimide is heat-treated, and the properties of the obtained thermosetting polyimide are insufficient. On the other hand, when the amount exceeds 1.0 mol, the mechanical properties of the obtained thermosetting polyimide deteriorate. The preferred amount is 0.01 to 0.5 mol.

Further, an aromatic dicarboxylic anhydride other than the above-mentioned dicarboxylic anhydride may be partially used in combination as long as the properties of the thermosetting polyimide of the present invention are not impaired. Examples of the aromatic dicarboxylic anhydride used here include phthalic anhydride, 2,3-benzophenone dicarboxylic anhydride, 3,4-benzophenone dicarboxylic anhydride, and 2,3-dicarboxyphenyl phenyl ether anhydride. , 3,4-dicarboxyphenylphenyl ether anhydride, 2,3-biphenyldicarboxylic anhydride, 3,4-biphenyldicarboxylic anhydride, 2,3-
Dicarboxyphenylphenyl sulfone anhydride, 3,4
-Dicarboxyphenylphenylsulfone anhydride, 2,
3-dicarboxyphenylphenyl sulfide anhydride,
3,4-dicarboxyphenylphenyl sulfide 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 is mentioned. These aromatic dicarboxylic anhydrides may be used alone or in combination of two or more.

As a method of adding and reacting a dicarboxylic anhydride, (a) a method of reacting a tetracarboxylic dianhydride with an aromatic diamine and then adding a dicarboxylic anhydride to continue the reaction; A) a method in which a dicarboxylic anhydride is added to an aromatic diamine to cause a reaction, and then a tetracarboxylic dianhydride is added and the reaction is further continued. (C) tetracarboxylic dianhydride, aromatic diamine, and dicarboxylic acid A method in which an anhydride is added at the same time and the reaction is carried out may be mentioned, and any addition method may be used. The method for producing the linear polyimide or linear polyamic acid of the present invention is not particularly limited, and all known methods can be applied. In this case, the linear polyimide represented by the formula (1) may partially contain the linear polyamic acid of the formula (2) which is a precursor thereof.

The reaction is usually performed in a solvent. Examples of the solvent used include N, N-dimethylformamide,
N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, N
-Methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-methylcaprolactam, 1,2-
Dimethoxyethane-bis (2-methoxyethyl) ether, 1,2-bis (2-methoxyethoxy) ethane, bis [2- (2-methoxyethoxy) ethyl] ether,
Tetrahydrofuran, 1,3-dioxane, 1,4-dioxane, pyridine, picoline, dimethylsulfoxide, sulfolane, dimethylsulfone, tetramethylurea, hexamethylphosphoramide, phenol, o-cresol, m-cresol, p-cresol, Cresylic acid, o-chlorophenol, m-chlorophenol,
Examples include p-chlorophenol, anisole, benzene, toluene, xylene and the like. These organic solvents may be used alone or in combination of two or more. By reacting the aromatic tetracarboxylic dianhydride and the aromatic diamine and dicarboxylic anhydride in an organic solvent,
A linear polyamic acid of the formula (2), which is a precursor corresponding to the linear polyimide of the present invention represented by the formula (1), is obtained. Conditions such as temperature, time and pressure for this reaction are not particularly limited, and known conditions can be applied.

The linear polyamic acid represented by the formula (2) has a logarithmic viscosity measured at 35 ° C. in N, N-dimethylacetamide at a concentration of 0.5 g / dl and a value of 0.05 to 0.05.
It is in the range of 1.0 dl / g. If it is less than 0.05 dl / g, the mechanical properties of the thermosetting polyimide of the present invention obtained after the heat treatment are extremely reduced. If it exceeds 1.0 dl / g, a thermosetting polyimide cannot be obtained even if a sufficient heat treatment is applied. Next, the obtained linear polyamic acid is thermally or chemically imidized to obtain a corresponding linear polyimide. Chemical imidization is a method of chemically imidizing using a dehydrating agent such as acetic anhydride, trifluoroacetic anhydride, polyphosphoric acid, phosphorus pentoxide or thionyl chloride. In this case, pyridine, imidazole, picoline and its isomer Quinoline and its isomers, organic bases such as alkylamines represented by triethylamine and the like, and inorganic bases represented by sodium hydroxide, potassium hydroxide and the like may coexist. In addition, heat imidization is
After the linear polyamic acid is produced and reacted, the solution is heated to perform imidization. In this case as well, the base can coexist as in the chemical imidization method.

The reaction temperature of the imidization is from 0 to 400 ° C., preferably from 0 to 150 ° C. for the chemical imidization, and preferably from 150 to 350 ° C. for the thermal imidization.
It is in the range of ° C. 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, the reaction temperature and the method of imidization, but is usually 0.1 to 48.
Time is enough. By the above method, the linear polyimide of the present invention can be manufactured.

The thermosetting polyimide of the present invention can be obtained by heat treating the linear polyimide or linear polyamic acid obtained as described above, or a mixture thereof. That is, to obtain a thermosetting polyimide, the linear polyimide of the present invention is used. Further, a part of the linear polyimide may be a linear polyamic acid as a precursor thereof. Further, the linear polyamic acid of the present invention itself can be subjected to a heat treatment to simultaneously carry out a thermal crosslinking reaction and a thermal imidization. The heating temperature varies depending on the type of the linear polyimide or linear polyamic acid or the type of the aromatic dicarboxylic anhydride represented by the above formula (1-5).
It is 0-500 degreeC, Preferably it is 250-450 degreeC, More preferably, it is the range of 300-400 degreeC. 2
At a temperature lower than 00 ° C., the thermal crosslinking reaction hardly occurs, and 50 ° C.
If the temperature exceeds 0 ° C., denaturation of the linear polyimide or linear polyamic acid occurs, and the properties of the thermosetting polyimide cannot be sufficiently obtained. The heat treatment time varies depending on the type of the linear polyimide, the linear polyamic acid or the aromatic dicarboxylic anhydride and the heat treatment temperature to be carried out.
It ranges from 1 minute to 24 hours. Preferably it is 1 minute to 1 hour, more preferably 5 to 30 minutes.
If the time is shorter than 0.1 minute, the thermal crosslinking reaction does not sufficiently occur, and a thermosetting polyimide cannot be obtained. Also, if the time is longer than 24 hours, the resulting thermosetting polyimide is denatured,
The properties of thermosetting polyimide cannot be obtained sufficiently. The heat treatment pressure is not particularly limited, and can be sufficiently performed at normal pressure.

In order to control the reaction rate by promoting or suppressing the thermal crosslinking reaction,
Metal catalysts containing gallium, germanium, indium or lead, transition metal catalysts containing molybdenum, manganese, nickel, cadmium, cobalt, chromium, iron, copper, tin or platinum, or phosphorus compounds, silicon compounds, nitrogen compounds or sulfur Compounds can be added. For the same purpose as described above, infrared rays, ultraviolet rays, α, β or γ
Irradiation such as radiation, electron beam or X-ray, plasma treatment or doping treatment may be performed. When performing the heat treatment, the form of the linear polyimide or the linear polyamic acid is not particularly limited. After the obtained linear polyimide or linear polyamic acid is formed into a solid, suspension or solution such as powder, granule or lump, heat treatment can be performed. In the case of solids, depending on the required shape,
For example, it can be a film, a sheet, a fiber, or a molded article having various shapes. In this case, a known molding method such as melting, extrusion, sintering, blowing, and calendering can be used. When a solvent is used, the same shape as that of the solid body can be obtained while removing the solvent depending on the heat treatment conditions.

Further, solids such as powders, granules and lumps,
Carbon fiber, glass fiber and various other inorganic fibers, aramid fiber, polybenzoxazole, heterocyclic polymer fiber such as polybenzthiazole and various chemical fibers, and those obtained from the suspension or solution are used. After mixing or impregnating the woven fabric or paper-like sheet, it is also possible to perform a heat treatment. Further, they are applied on a material such as a plate, foil or rod made of metal, ceramic, plastic or glass and heat-treated, or after being applied, the same or different materials are overlapped and sandwiched, and both are heat-treated simultaneously. Can be adhered. When performing the bonding, it is desirable to perform the bonding under pressure.

The thermosetting polyimide of the present invention may be a thermoplastic resin, for example, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polybutadiene, polystyrene, polyvinyl acetate, ABS resin, or a thermoplastic resin as long as the object of the present invention is not impaired. Butylene terephthalate, polyethylene terephthalate, polyphenylene oxide, PT
FE, celluloid, polyether nitrile, polycarbonate, polyarylate, polyamide, polysulfone,
Polyetherimide, polyether sulfone, polyether ether ketone, polyether ketone, polyphenylene sulfide, polyamide imide, modified polyphenylene oxide and polyimide or the like, or other thermosetting resins such as thermosetting polybutadiene, formaldehyde resin, amino resin, Polyurethane, silicone resin, SB
R, NBR, unsaturated polyester, epoxy resin, polycyanate, phenolic resin and the like may be used in appropriate amounts of one or more resins according to the purpose. The compounding method is not particularly limited. Further, the thermosetting polyimide of the present invention can be used by mixing two or more kinds in an appropriate amount according to the purpose. It is also possible to mix one or more of the above resins with the mixed thermosetting polyimide within a range not to impair the object of the present invention. Further, the following fillers and the like may be used as long as the object of the present invention is not impaired. That is, abrasion resistance improvers such as graphite, carborundum, silica stone powder, molybdenum disulfide, and fluororesin, reinforcing agents such as glass fiber and carbon fiber, and flame retardant such as antimony trioxide, magnesium carbonate, and calcium carbonate. Improver, electric property improver such as clay, mica, etc., tracking improver such as asbestos, silica, graphite, etc., acid resistance improver such as barium sulfate, calcium metasilicate, iron powder, zinc powder, aluminum powder, copper powder And other thermal conductivity improvers, such as glass beads, glass spheres, talc, diatomaceous earth, alumina, silica balun, hydrated alumina, metal oxides, coloring agents and the like.
The composite material of the present invention is a composition before heat treatment containing the linear polyimide and / or linear polyamic acid of the present invention and a fibrous reinforcing material, or a thermosetting polyimide obtained by heat-treating this composition and a fibrous reinforcing material. And a thermosetting polyimide composite material.

Examples of the fibrous reinforcing material used in the composite material of the present invention include unidirectional long fibers such as glass fiber yarns, ropings, carbon fiber tows or two-dimensional or three-dimensional materials such as woven fabrics, mats and felts. A dimensional multidirectional continuous fibrous body may be used. These fibrous reinforcing materials include glass fibers such as E-glass, C-glass, and AR-glass, carbon fibers made of PAN, pitch, or rayon, graphite fibers, and aromatic polyamides represented by Kepler of DuPont. Fiber, silicon carbide fiber such as Nicalon of Nippon Carbon Co., metal fiber such as stainless steel fiber, other alumina fiber, boron fiber, and the like.These fibers may be used alone or in combination. It can be used in combination with other reinforcing materials such as fiber, mica, calcium silicate, and the like, and the mixing ratio is not limited and is determined according to required performance. In selecting the fibrous reinforcing material used in the present invention from the various reinforcing materials described above, the strength, elastic modulus, mechanical properties such as elongation at break of the fiber, electrical properties, specific gravity, etc. Should be selected according to the required characteristics. For example, specific strength,
When the required value for the specific elastic modulus is high, carbon fiber, glass fiber, or the like should be selected. When electromagnetic wave shielding characteristics are required, carbon fiber, metal fiber, or the like is preferable. When electrical insulation properties are required, glass fiber or the like is suitable.

The fiber diameter and the number of convergent fibers of the fibrous reinforcing material differ depending on the type of the fibrous reinforcing material used. It is. The smaller the fiber diameter is, the better the mechanical properties of the obtained composite material are. However, not limited to those specified here, various types can be used. Further, in the case of a woven fabric or the like, there is no limitation on the weaving method, thickness, etc., and any type of woven fabric can be used. Also, as for the other fiber reinforcing materials, there are no restrictions on the types, shapes, etc., as in the case of the carbon fibers. Further, surface treatment of the fibrous reinforcing material is preferable from the viewpoint of improving adhesion to the matrix resin, and a known surface treatment can be applied. For example, in the case of glass fiber, it is particularly preferable to treat with a silane-based or titanate-based coupling agent or to treat carbon fiber with an aromatic polyether or a polysulfone that is a heat-resistant polymer. The volume content of these fibrous reinforcing materials in the composite material is 5 to 85%, preferably 3 to 85%.
0 to 70%. If the volume content of the fibrous reinforcing material is low, the effect of the reinforcing material cannot be expected, while if it is high, the interlayer strength of the obtained composite material is significantly reduced, which is not preferable. Among the composite materials of the present invention, the method for producing the composite material before the heat treatment is not particularly limited as long as the target composite material can be obtained, and any known method can be applied. A linear polyimide and / or linear polyamic acid and a fibrous reinforcing material are mixed, or a solid, suspension or solution of linear polyimide and / or linear polyamic acid is applied or impregnated to the fibrous reinforcing material. Can be manufactured. As a method for impregnating the fibrous reinforcing material with linear polyimide and / or linear polyamic acid, all known methods can be applied, and for example, the following method is often used, for example.
1) A method in which a suspension or solution of a linear polyimide and / or a linear polyamic acid is applied to a fibrous reinforcing material or immersed in a fibrous reinforcing material for impregnation. 2) A method of impregnating a powder of linear polyimide and / or linear polyamic acid in a state of being suspended in a gas such as air.

The solvent used in the method 1) is not particularly limited. In addition to the solvents used for producing linear polyimide and / or linear polyamic acid, ketones such as acetone and methyl ethyl ketone, methanol, ethanol, isopropanol, etc. Alcohols, ethers such as dioxane and tetrahydrofuran, hydrocarbons such as hexane, heptane, cyclohexane, benzene, toluene, xylene and anisole, and hydrogen atoms of the hydrocarbons represented by dichloromethane, chloroform, chlorobenzene and fluorobenzene. Halogenated hydrocarbons in which part or all of are replaced with halogen atoms, ester compounds such as ethyl acetate, butyl acetate, and ethyl formate; phenol compounds such as cresol and phenol; amine compounds such as pyridine, picoline and triethylamine; Horan, dimethyl sulfoxide sulfur-based, and such water is used by itself or mixed. In the method of 1), the solution or suspension has a concentration,
There are no particular restrictions on the dissolution temperature, dissolution time, diameter and shape of the suspended particles, and the like.

As a method for producing a composite material comprising a fibrous reinforcing material and linear polyimide and / or linear polyamic acid, for example, the following general method can be mentioned. That is, a unidirectional long fiber drawn from a plurality of bobbins, for example, a fiber sheet in which tows are aligned or a multidirectional continuous fiber is applied with a constant tension in a pulling direction by a tension adjusting roll. On the other hand, a liquid containing linear polyimide and / or linear polyamic acid is discharged from a die and applied to the roll surface. The coating thickness is determined by the set percentage of resin content in the resulting composite material. Next, the above-described fiber sheet or multidirectional continuous fiber is brought into contact with the roll surface with a certain tension to impregnate the roll. After further impregnation by the above method,
Heat and dry to remove the solvent used. In this drying, the linear polyamic acid is also partially dehydrated and subjected to ring-closing imidization at the same time. The drying temperature depends on the type of the solvent and the concentration of the solvent or the suspension, but is preferably from 50 to 300 ° C, more preferably from 150 to 250 ° C. If the temperature exceeds 300 ° C., the crosslinking reaction proceeds and the solvent removal tends to be incomplete, which is not preferable. If the temperature is lower than 50 ° C., it is often not dried sufficiently. The atmosphere is not particularly limited, such as air, nitrogen, helium, neon, and argon, but nitrogen and argon are preferably selected. The drying time depends on the drying temperature, the type of solvent and the concentration of the solution or suspension, but is preferably 0.5 to 48 hours, more preferably 1 to 6 hours. The drying pressure is not particularly limited, and may be normal pressure or reduced pressure. Others
There is no particular limitation on the type of dryer and the drying method for drying.

The composite material containing the thermosetting polyimide and the fibrous reinforcing material of the present invention is obtained by subjecting the composite material obtained as described above to a heat treatment to obtain a molecule of linear polyimide and / or linear polyamic acid. It is obtained by a curing reaction based on thermal crosslinking of a carbon-carbon double bond contained in the terminal.

The heat treatment temperature for thermosetting is usually from 200 to
500 ° C., preferably 250-450 ° C.,
More preferably, it is in the range of 300 to 400 ° C. 20
At a temperature lower than 0 ° C., the thermal crosslinking reaction hardly proceeds, and at a temperature exceeding 500 ° C., the linear polyimide or linear polyamic acid is denatured, so that the properties of the thermosetting polyimide cannot be sufficiently obtained.

The heat treatment time varies depending on the kind of the linear polyimide or the linear polyamic acid or the aromatic dicarboxylic anhydride and the heat treatment temperature to be carried out, but is usually in the range of 0.1 minute to 24 hours. Preferably it is 1 minute to 1 hour, more preferably 5 to 30 minutes. 0.1
If the time is shorter than minutes, the thermocrosslinking reaction does not sufficiently proceed, and a thermosetting polyimide cannot be obtained. If the time is longer than 24 hours, the resulting thermosetting polyimide is denatured, and the properties of the thermosetting polyimide cannot be sufficiently obtained.

The heat treatment pressure is not particularly limited, and it can be carried out at normal pressure. For example, a composite material containing a fibrous reinforcing material and a linear polyimide before heat treatment can be laminated and heated and compressed to produce a molded product having a desired shape.

In the case of producing a laminated composite material, various methods can be employed for the lamination method and the number of laminated layers depending on the required performance. Heat treatment, that is, the heating temperature during lamination molding is 30
If it is 0 ° C or more, there is no problem, and preferably 300 to 450
° C. The pressing force varies depending on the shape, but is 1 kg · c
m ^-2 or more is sufficient. The pressing time varies depending on the shape, but 1 minute or more is sufficient.

The thermal crosslinking reaction for converting the linear polyimide or linear polyamic acid into a thermosetting polyimide by heating may be performed simultaneously with the compression under pressure or separately after the compression under heat. The conditions for the thermal crosslinking reaction are as described above.

The composite material before and after the heat treatment of the present invention is compression molded,
Known molding methods such as autoclave molding, stamping molding, filament winding, and tape winding can be adopted, and the molding method is not particularly limited. The shape of the composite material is not limited, and examples thereof include a flat plate, a channel, an angle, a stringer, a round bar, and a valve.
However, it is needless to say that the present invention is not limited to these shapes, and any shape is possible.

[0041]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments. In addition, the physical properties of the polyimide in the examples were measured by the following methods. Glass transition temperature: DSC (Shimadzu DT-40 series, D
SC-41M) in a nitrogen stream at 16 ° C min- ¹
Measured at heating rate. 5% weight loss temperature: DTG (Shimadzu DT-40 series,
DTG-40M) in an air stream at 10 ° C min- ¹
Measured at heating rate. Logarithmic viscosity: Polyamic acid was measured in N, N-dimethylacetamide at a concentration of 0.5 g / 100 ml at 35 ° C. Mechanical properties of the film: Measurement of tensile strength, tensile elongation and tensile modulus was based on ASTM-D882.

Example 1 43.25 g (0.1 mol) of bis [4- (3-aminophenoxy) phenyl] sulfone and pyromellitic acid were placed in a vessel equipped with a stirrer, a reflux condenser and a nitrogen inlet tube. 21.16 g of dianhydride (0.09
7 mol) and N-methyl-2-pyrrolidone 135.0
g and stirred at 25 ° C. under a nitrogen atmosphere. Six hours later, 0.588 g (0.006 mol) of maleic anhydride was added, and stirring was continued for 18 hours. The logarithmic viscosity of the obtained linear polyamic acid of the precursor is 0.50 dl / g.
Met. The obtained solution of linear polyamic acid was cast on a glass plate using a doctor blade, and then dried at 200 ° C. for 12 hours under a nitrogen stream to obtain a linear polyimide film having a thickness of 40 μm before heat treatment. Obtained. The linear polyimide film before the heat treatment was subjected to DSC measurement. As a result, a glass transition temperature was observed at 250 ° C., and an exothermic peak due to a thermal crosslinking reaction was observed at 280 ° C. Further, 20 mg of the linear polyimide film before the heat treatment was put in 5 ml of p-chlorophenol and heated to completely dissolve at 150 ° C. On the other hand, the linear polyimide film before the heat treatment was heat-treated at 340 ° C. for 30 minutes under a nitrogen stream to obtain a thermosetting polyimide film having a thickness of 40 μm. DSC measurement of the thermosetting polyimide film after the heat treatment showed a glass transition temperature of 275 ° C., but no exothermic peak was detected. When a solubility test was carried out using p-chlorophenol in the same manner, it did not dissolve even after 1 hour in a refluxed condition under heating, and no change was observed by visual observation. The 5% weight loss temperature of the thermosetting polyimide film after the heat treatment was 490 ° C. Further, when the mechanical properties of the thermosetting polyimide film were measured, the tensile strength was 123 MPa and the tensile modulus was 3.1.
The tensile elongation was 6 GPa and the tensile elongation was 50%.

Examples 2 to 16 As shown in Tables 1 and 2, various linear amounts were prepared using various predetermined amounts of aromatic diamine, aromatic tetracarboxylic dianhydride and maleic anhydride, and various solvents. A polyamic acid was obtained. The logarithmic viscosities are shown in Tables 1 and 2 together with the results of Example 1. Subsequently, these linear polyamic acids were imidized in the same manner as in Example 1 to obtain various linear polyimide films. The glass transition temperature, exothermic peak and solubility test with p-chlorophenol of these films were performed in the same manner as in Example 1. The results are shown in Tables 3 and 4. Subsequently, these polyimide films were subjected to the same heat treatment as in Example 1 to obtain heat-cured polyimide films after various heat treatments. About the obtained polyimide film, the film thickness, the glass transition temperature, the exothermic peak, the solubility test with p-chlorophenol, the 5% weight loss temperature, and the mechanical properties were measured in the same manner as in Example 1. Tables 3 and 4 show the results together with the results of Example 1.

(Comparative Examples 1-2) As shown in Table 5, various lines were prepared by using various predetermined amounts of aromatic diamine, aromatic tetracarboxylic dianhydride and aromatic dicarboxylic anhydride, and various solvents. A polyamic acid was obtained. Table 5 shows their logarithmic viscosities. Subsequently, these linear polyamic acids were imidized in the same manner as in Example 1 to obtain respective imide films. The same measurement as in Example 1 was performed for each of the obtained polyimide films. Table 6 shows the results.

Examples 17 to 19 As shown in Table 7, composite materials were obtained using the linear polyamic acid solutions obtained in Examples 1, 3 and 6 and the unidirectional long fibers. That is, 100 carbon fiber tows (Vesfight HTA-7-3000) drawn out from 100 bobbins were aligned to form a fiber sheet having a width of 150 mm. The above linear polyamic acid solution was passed through a die using a metering pump to 240 mm.
The fiber sheet was applied to a roll having a diameter of 240 μm to a thickness of 240 μm, and the fiber sheet was brought into contact with the roll surface at a tension of 150 kg to impregnate the fiber sheet with linear polyamic acid. Next, the fiber sheet impregnated with the solution was dried while moving at a speed of 10 cm / min in a drying furnace for 30 minutes in an air stream at 150 ° C. Further, at the same speed under a nitrogen stream at 240 ° C 3
After passing through a drying oven for 0 minutes, it was cooled and wound up by a take-up machine.
The obtained prepreg has a width of 150 mm and a thickness of 0.15 mm.
It was. Twenty prepregs were laminated in the same direction, hot-pressed at 370 ° C. and 2 MPa for 20 minutes, and cooled to 100 ° C. while maintaining the pressure.
A flat plate of 0 × 200 mm was obtained. Internal void ratio of this thing, cut out a predetermined test piece from the flat plate further, bending strength,
The flexural modulus was measured according to ASTM-790. Table 7 shows the results. The internal void ratio is determined from the specific gravity of the flat plate and the percentage by weight of the fiber content.

(Examples 20 to 22) Acetic anhydride and pyridine were added to each solution of the linear polyamic acid obtained in Examples 1, 2 and 7 at room temperature, and the mixture was chemically stirred at room temperature for 5 hours. Imidation was performed to obtain a powder of each polyimide.
A suspension having a concentration of 25 wt% was prepared from each of the obtained three kinds of linear polyimide powders using methyl ethyl ketone, methanol, and hexane, respectively. Using these three suspensions, prepregs were obtained in exactly the same manner as in Examples 17 to 19. However, the impregnation using the suspension was performed on a steel belt having a width of 240 mm and a flat portion of 300 mm without using a roll. Thereafter, drying, press lamination, and heat treatment were performed in the same manner as in Examples 17 to 19. The obtained composite material was evaluated in the same manner as in Examples 17 to 19, and the results shown in Table 7 were obtained.

(Examples 23 and 24) The linear polyamic acid solution obtained in Example 1 and the linear polyamic acid solution obtained in Example 3 were chemically imidized in the same manner as in Examples 20 to 22. A prepreg was obtained by the following method using a suspension comprising the linear polyimide powder and methyl ethyl ketone obtained as described above and a carbon fiber plain woven fabric as a fibrous reinforcing material. The multi-directional continuous fiber suspended on the pay-out shaft was passed through a tension adjusting roll with a tension of 30 kg in the take-up direction while being in contact with a roll having a diameter of 240 mm. On the other hand, the solution and the suspension were applied on a steel belt having a width of 240 mm and a flat portion of 300 mm from a die by a metering pump, and the fibers were brought into contact with the belt surface to be impregnated. Drying, press lamination, and heat treatment were performed in the same manner as in Examples 17 to 19. The obtained composite material was evaluated in the same manner as in Examples 17 to 19, and the results shown in Table 7 were obtained.

[0048]

(Examples 25 and 26) The carbon fiber plain woven fabrics in Examples 23 and 24 using the solution of the linear polyamic acid of Example 3 and the suspension of the linear polyimide obtained in Example 6 In place of the above, a composite material was obtained in the same manner as in Examples 23 and 24, except that a plain woven fabric of glass fiber was used as a cloth fibrous reinforcing material. Table 7 shows the evaluation results of the obtained composite materials.

[0050]

[Table 1]

[0051]

[Table 2] Description of abbreviations in Tables 1 and 2 APS; bis [4- (3-aminophenoxy) phenyl] sulfone ODA; 4,4′-diaminodiphenyl ether PMDA; pyromellitic dianhydride BPDA; 3,3 ′, 4 N, N-methyl-2-pyrrolidone DMI, 1,3-dimethyl-2-imidazolidinone DMA, N, N-dimethylacetamide DMF, N, N-dimethylformamide mCr; m-cresol

[0052]

[Table 3]

[0053]

[Table 4] Description of abbreviations in Tables 3 and 4 TS; Tensile strength EL; Tensile elongation TM; Dissolution IS. Insoluble ND. ; Not detected

[0054]

[Table 5] Description of abbreviations in Table 5 APS; bis [4- (3-aminophenoxy) phenyl] sulfone ODA; 4,4'-diaminodiphenyl ether PMDA; pyromellitic dianhydride MA; maleic anhydride PA; phthalic anhydride NMP N-methyl-2-pyrrolidone

[0055]

[Table 6] Description of abbreviations in Table 6 TS; Tensile strength EL; Tensile elongation TM; Dissolution ND. ; Not detected

[0056]

[Table 7] Description of abbreviations in Table 7 FS; flexural strength FM; flexural modulus A. S. Polyamic acid solution I .; S. ; Polyimide suspension G; glass fiber C; carbon fiber

[0057]

The thermosetting polyimide obtained by the method of the present invention has excellent resistance to chemicals and heat, and has excellent workability and mechanical properties. The application of is greatly expected.

Continued on the front page (72) Inventor, Satoshi Ikeda 30 Asamuta-cho, Omuta-shi, Fukuoka Mitsui Chemicals, Inc. (72) Inventor Fumiaki Kuwano 31-8, Omiya Miyabe, Omuta-shi, Fukuoka

Claims (12)

[Claims] (1) Formula (1) (Wherein P1 is the following formula (a) or formula (b): Wherein S1 is a repeating unit represented by the formula (c) or the formula (d): Wherein m and n represent mol% of each repeating unit, and m is 100 to
1 mol%, n is 0 to 99 mol%, and there is no regularity or regularity between the repeating units. 1 represents the degree of polymerization, and is an integer of 1 to 100. The linear polyimide represented by). 2. A compound of the formula (2), which is a precursor of the linear polyimide according to claim 1. Wherein P2 is (e) or (f) Wherein S2 is a group represented by the formula (g) or the formula (h): At least one of monovalent groups represented by m, n,
And l are the same as in the case of the formula (1)].
The linear polyimide according to claim 1, wherein the amount is from 0.05 to 1.0 dl / g. (3) Formula (3) [Wherein, S3 is represented by the formula (i) or (j)] At least one of monovalent groups represented by
Represents mol% of each repeating unit, and m represents 100 to 7
0 mol%, n is 0 to 30 mol%, and there is no regularity or regularity between the repeating units. 1 represents the degree of polymerization, and is an integer of 1 to 100. The linear polyimide represented by). 4. A compound of the formula (5) (Wherein m and n represent mol% of each repeating unit, m is 100 to 70 mol%, n is 0 to 30 mol%, and the regularity and regularity between the repeating units are Absent.
1 represents the degree of polymerization, and is an integer of 1 to 100. The linear polyimide represented by). 5. The precursor of the linear polyimide according to claim 1, which has a logarithmic viscosity (N, N-dimethylacetamide solvent, concentration: 0.5 g / dl, measured at 35 ° C.) of 0. A linear polyamic acid having a weight of from 0.05 to 1.0 dl / g. 6. A thermosetting polyimide obtained by heat-treating the linear polyimide according to claim 1. 7. A thermosetting polyimide obtained by heat-treating the linear polyamic acid according to claim 5. 8. A composite comprising the linear polyimide according to claim 1 and a fibrous reinforcing material. 9. A composite comprising the linear polyamic acid according to claim 5 and a fibrous reinforcing material. 10. A composite material comprising a thermosetting polyimide obtained by heat-treating the composite material according to claim 8 and a fibrous reinforcing material. 11. A solution or suspension containing the linear polyimide according to claim 1. 12. A solution or suspension containing the linear polyamic acid according to claim 4.