JP2596566B2 - Polyimide having good thermal stability and method for producing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a polyimide for melt molding. More specifically, the present invention relates to a polyimide having good heat stability and excellent moldability and a method for producing the same.

[Conventional technology]

Conventionally, polyimides obtained by the reaction of tetracarboxylic dianhydride and aromatic diamine have high heat resistance, excellent mechanical strength, excellent dimensional stability, flame retardancy, electrical insulation, etc. It is used in fields such as electronic equipment, aerospace equipment, and transportation equipment, and is expected to be widely used in fields that require co-heat resistance in the future.

Conventionally, various polyimides exhibiting excellent characteristics have been developed. However, even if it is excellent in heat resistance, it does not have a clear glass transition temperature, so if it is used as a molding material, it must be processed using a method such as sintering molding, and the workability is excellent However, it has a low glass transition temperature, is soluble in halogenated hydrocarbons, and is not satisfactory in terms of heat resistance and solvent resistance, and has advantages and disadvantages in performance.

On the other hand, the present inventor has previously described a polyimide having excellent mechanical properties, thermal properties, electrical properties, solvent resistance and the like and having heat resistance as shown in the following formula (A). (Where X is a direct bond, a divalent hydrocarbon group having 1 to 10 carbon atoms,
Hexafluorinated isopropylidene group, carbonyl group,
Represents a group selected from the group consisting of a thio group or a sulfonyl group, and Y ₁ , Y ₂ , Y ₃ and Y ₄ are each independently selected from the group consisting of hydrogen, a lower alkyl group, a lower alkoxy group, chlorine and bromine. R represents an aliphatic group having 2 or more carbon atoms, a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, or an aromatic group connected directly or by a crosslinking member. Selected from the group consisting of non-fused polycyclic aromatic groups
Represents a valence group. Polyimide having a repeating unit represented by ()) was found. (JP-A-61-143478, JP-A-62-68)
817, 62-86021, Japanese Patent Application Nos. 61-076475 and 61-274206). The above-mentioned polyimide is a novel heat-resistant resin having many good physical properties. However, although the above-mentioned polyimide shows excellent fluidity and is a polyimide having good processability, when it is kept at a high temperature for a long time (for example,
If, for example, the resin is kept at a high temperature for a long time during injection molding, the fluidity of the molten resin gradually decreases, and the moldability decreases.

[Problems to be solved by the invention]

An object of the present invention is to provide an excellent polyimide which has good thermal stability and does not deteriorate in moldability even when kept at a high temperature for a long time, in addition to the excellent properties inherent to polyimide.

[Means for solving the problem]

The present inventors have conducted intensive studies to solve the above-mentioned problems and achieved the present invention.

That is, the present invention relates to (a) the general formula (I) (Wherein, Y ₁ , Y ₂ , Y ₃ and Y ₄ each independently represent a group selected from the group consisting of hydrogen, methyl group, methoxy group, chlorine and bromine.) B) General formula (II) (Where R is Represents a tetravalent group selected from the group consisting of A) a tetracarboxylic dianhydride represented by the general formula (III) Z-NH ₂ (III) (wherein Z is Represents a monovalent group selected from the group consisting of (D) the amount of aromatic diamine is 0.9 to 1.0 mole ratio per mole of tetracarboxylic dianhydride and the amount of aromatic monoamine is 1 mole of tetracarboxylic dianhydride; 0.01 to 0 per hit.
General formula (IV) obtained by reacting at a molar ratio of 5 Wherein Y ₁ , Y ₂ , Y ₃ , Y ₄ and R are the same as defined above, and the terminal of the polymer molecule is represented by the formula (IV-a) (Wherein R and Z are the same as above), and a polyimide having good thermal stability and a method for producing the same.

The diamine represented by the formula (I) used in the method of the present invention includes 4,4'-bis (3-aminophenoxy)
Biphenyl, 4,4'-bis (3-aminophenoxy)-
3-methylbiphenyl, 4,4'-bis (3-aminophenoxy) -3,3'-dimethylbiphenyl, 4,4'-bis (3-aminophenoxy) -3,5'-dimethylbiphenyl, 4,4 '-Bis (3-aminophenoxy) -3,3', 5,
5'-tetramethylbiphenyl, 4,4'-bis (3-aminophenoxy) -3,3'-dichlorobiphenyl, 4,4'-
Bis (3-aminophenoxy) -3,5'-dichlorobiphenyl, 4,4'-bis (3-aminophenoxy) -3,
3 ', 3,5'-tetrachlorobiphenyl, 4,4'-bis (3
-Aminophenoxy) -3,3'-dibromobiphenyl,
4,4'-bis (3-aminophenoxy) -3,5-dibromobiphenyl, 4,4'-bis (3-aminophenoxy)-
3,3 ', 3,5'-tetrabromobiphenyl and the like. These may be used alone or in combination of two or more.

In addition, as long as the good physical properties of the polyimide of the method of the present invention are not impaired, one part of the above diamine may be used in place of another aromatic diamine.

As a diamine that can be used as a partial substitute,
For example, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, bis (3-aminophenyl) ether, (3-aminophenyl) (4-aminophenyl) ether , Bis (4-aminophenyl) ether, bis (3-aminophenyl) sulfide, (3-
Aminophenyl) (4-aminophenyl) sulfide,
Bis (4-aminophenyl) sulfide, bis (3-aminophenyl) sulfoxide, (3-aminophenyl)
(4-aminophenyl) sulfoxide, bis (4-aminophenyl) sulfoxide, bis (3-aminophenyl) sulfone, (3-aminophenyl) (4-aminophenyl) sulfone, bis (4-aminophenyl) sulfone, 3 , 3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, bis [4- (4-aminophenoxy) phenyl] methane,
1,1-bis [4- (4-aminophenoxy) phenyl]
Ethane, 1,2-bis [4- (4-aminophenoxy) phenyl] ethane, 1,2-bis [4- (4-aminophenoxy) phenyl] ethane, 2,2-bis [4- (4-amino Phenoxy) phenyl] propane, 2,2-bis [4-
(4-aminophenoxy) phenyl] butane, 2,2-bis [4- (4-aminophenoxy) phenyl] -1,1,1,
3,3,3-hexafluoropropane, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,4-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-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, bis [4- (4-aminophenoxy) phenyl] ether, 1,4- Screw [4
-(3-aminophenoxy) benzoyl] benzene, 1,
3- [4- (3-aminophenoxy) benzoyl] benzene, bis [4- (3-aminophenoxy) phenyl]
Methane, 1,1-bis [4- (3-aminophenoxy) phenyl] ethane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2- [4- (3-aminophenoxy) phenyl ] -2- [4- (3-aminophenoxy) -3-methylphenyl] propane, 2,2-bis [4- (3-aminophenoxy) -3-methylphenyl] propane, 2- [4- (3 -Aminophenoxy) phenyl] -2- [4- (3-aminophenoxy) -3,5
-Dimethylphenyl] propane, 2,2-bis [4- (3
-Aminophenoxy) -3,5-dimethylphenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] butane, 2,2-bis [4- (3-aminophenoxy) phenyl] -1 , 1,1,3,3,3-hexafluoropropane, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl]
Sulfide, bis [4- (3-aminophenoxy) -3
-Methoxyphenyl] sulfide, [4- (3-aminophenoxy) phenyl] [4- (3-aminophenoxy) -3,5-dimethoxyphenyl] sulfide, bis [4- (3-aminophenoxy) -3,5 -Dimethoxyphenyl] sulfide, bis [4- (3-aminophenoxy) phenyl] sulfone and the like.

Examples of the tetracarboxylic dianhydride represented by the formula (II) used in the method of the present invention include ethylene tetracarboxylic dianhydride, butanetetracarboxylic dianhydride, and cyclopentanetetracarboxylic dianhydride. Product, pyromellitic dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-di (Carboxyphenyl) methane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2- Screw (3,4
-Dicarboxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) -1,1,1,3,3, 3-hexafluoropropane dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 2,2', 3,3'-benzophenonetetracarboxylic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl)
Ether dianhydride, bis (2,3-dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, 4,4 '-(p-phenyleneoxy) diphthalic dianhydride Product, 4,4 '-(m-phenylenedioxy) diphthalic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride Compound, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride and 1,2,7,8-phenanthrene tetracarboxylic dianhydride.These tetracarboxylic dianhydrides may be used alone or in combination of two or more. Used.

The aromatic monoamine represented by the formula (III) used in the method of the present invention includes, for example, aniline, o-toluidine, m-toluidine, p-toluidine, 2,3-xylidine, 2,4-xylidine, 2,5-xylidine, 2,6-
Xylidine, 3,4-xylidine, 3,5-xylidine, o-
Chloroaniline, m-chloroaniline, p-chloroaniline, o-bromoaniline, m-bromoaniline, p-
Bromoaniline, o-nitroaniline, m-nitroaniline, p-nitroaniline, o-aminophenol, m
-Aminophenol, p-aminophenol, o-anisidine, m-anisidine, p-anisidine, o-phenetidine, m-phenetidine, p-phenetidine, o-aminobenzaldehyde, m-aminobenzaldehyde,
p-aminobenzaldehyde, o-aminobenzotrifluoride, m-aminobenzotrifluoride, p-aminobenzotrifluoride, o-aminobenzonitrile,
m-aminobenzonitrile, p-aminobenzonitrile, 2-aminobiphenyl, 3-aminobiphenyl, 4
-Aminobiphenyl, 2-aminophenyl phenyl
Ether, 3-aminophenyl phenyl ether,
4-aminophenyl phenyl ether, 2-aminobenzophenone, 3-aminobenzophenone, 4-aminobenzophenone, 2-aminophenyl phenyl sulfide, 3-aminophenyl phenyl sulfide, 4-aminophenyl phenyl sulfide, 2-
Aminophenyl phenyl sulfone, 3-aminophenyl phenyl sulfone, 4-aminophenyl phenyl sulfone, 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-
Examples thereof include amino-2-naphthol, 8-amino-1-naphthol, 8-amino-2-naphthol, 1-aminoanthracene, 2-aminoanthracene, and 9-aminoanthracene, and these may be used alone or in combination of two or more. Used.

The molar ratio of the tetracarboxylic dianhydride, aromatic diamine and aromatic monoamine used in the method of the present invention is 0.9 to 1.0 mol of aromatic diamine and 1 mol of aromatic monoamine per 1 mol of tetracarboxylic dianhydride. 0.001 to 1.0 mol.

In the production of polyimide, it is customary to adjust the ratio of tetracarboxylic dianhydride to aromatic diamine in order to adjust the molecular weight of the resulting polyimide.
In the method of the present invention, the molar ratio of the aromatic diamine to the tetracarboxylic dianhydride is from 0.9 to 1.0 in order to obtain a polyimide having good melt flowability.

The co-existing aromatic monoamine is used in a molar ratio of 0.001 to 1.0 with respect to tetracarboxylic dianhydride. If the molar ratio is less than 0.001, the thermal stability at a high temperature intended for the present invention cannot be obtained. If the molar ratio exceeds 1.0, the mechanical properties deteriorate. The preferred amount is 0.01 to
0.5 molar ratio.

 In the method of the present invention, the reaction is performed in an organic solvent.

As the organic solvent used in this reaction, for example, 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, dimethyl sulfoxide, dimethyl sulfone, tetramethyl urea, hexamethyl phosphoramide, phenol, m-cresol, p-
Cresol, p-chlorophenol, anisole and the like can be mentioned. These organic solvents may be used alone or in combination of two or more.

The method of adding tetracarboxylic dianhydride, aromatic diamine, and aromatic monoamine to the organic solvent in the method of the present invention and reacting them includes: (a) reacting tetracarboxylic dianhydride with aromatic diamine; (B) a method of adding an aromatic monoamine and continuing the reaction, (b) a method of adding an aromatic monoamine to tetracarboxylic dianhydride and reacting, adding an aromatic diamine, and further continuing the reaction; Any addition and reaction may be performed, such as a method of simultaneously adding and reacting tetracarboxylic dianhydride, aromatic diamine, and aromatic monoamine.

The reaction temperature is from 0 ° C to 250 ° C. Usually, it is performed at a temperature of 600 ° C. or less.

 The reaction pressure is not particularly limited, and the reaction can be sufficiently performed at normal pressure.

The reaction time varies depending on the type of tetracarboxylic dianhydride, aromatic diamine, aromatic monoamine, solvent used and the reaction temperature, but usually 4 to 24 hours is sufficient.

By such a reaction, a polyamic acid having a repeating unit represented by the following formula (V) is generated.

(Wherein Y ₁ , Y ₂ , Y ₃ , Y ₄ and R are the same as described above). The polyamic acid is dehydrated by heating to 100 to 400 ° C. or a commonly used imidizing agent such as triethylamine and acetic anhydride. And a polyimide corresponding to the repeating unit of the following formula (IV) is obtained.

( (In the formula, Y ₁ , Y ₂ , Y ₃ , Y ₄ and R are the same as described above.) In the general formula, after a polyimide acid is formed at a low temperature, it is further thermally or chemically imidized. Is done. However, at a temperature of 60 ° C. to 250 ° C., the polyimide can be obtained by simultaneously performing the polyamic acid generation and the thermal imidization reaction. That is, after the tetracarboxylic dianhydride, aromatic diamine, aromatic monoamine is suspended or dissolved in an organic solvent, the reaction is performed under heating, and the polyamic acid is simultaneously generated and dehydrated by imidization. A polyimide comprising a repeating unit of the formula (IV) can also be obtained.

When subjecting the polyimide of the present invention to melt molding, other thermoplastic resins within a range that does not impair the purpose of the present invention, for example,
An appropriate amount of polyethylene, polypropylene, polycarbonate, polyarylate, polyamide, polysulfone, polyethersulfone, polyetherketone, polyphenylenesulfide, polyamideimide, polyetherimide, modified polyphenylene oxide, etc. can be blended in an appropriate amount depending on the purpose. . Further, the following fillers and the like used in ordinary resin compositions may be used to the extent that the object of the invention is not impaired. That is, graphite, carborundum, silica stone powder, molybdenum disulfide, abrasion resistance improving material such as fluororesin, glass fiber, carbon fiber,
Reinforcing material such as boron fiber, silicon carbide fiber, carbon whisker, asbestos, metal fiber, ceramic fiber, flame retardant improver such as antimony trioxide, magnesium carbonate, calcium carbonate, etc., electric property improving material such as clay and mica, Tracking resistance improvers such as asbestos, silica and graphite, acid resistance improvers such as barium sulfate, silica and calcium metasilicate, heat conductivity improvers such as iron powder, zinc powder, aluminum powder and copper powder, and other glass beads, Glass spheres, talc, diatomaceous earth, alumina, shirasubarun, hydrated alumina, metal oxides, coloring agents and the like.

〔Example〕

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.

Example 1 218 g (1.0 mol) of pyromellitic dianhydride was placed in a reaction vessel equipped with a stirrer, a reflux condenser, and a nitrogen inlet tube.
Charge N, N-dimethylacetamide (3,830 g) and add aniline
5.58 g (0.06 mol) was added and stirred for about 20 minutes.

Next, 357 g (0.97 mol) of 4,4'-bis (3-aminophenoxy) biphenyl was added while paying attention to the rise in the solution temperature, and the mixture was stirred at room temperature for about 10 minutes. Then, in this solution
202 g (2 mol) of triethylamine and 255 g (2.5 mol) of acetic anhydride were added dropwise. The mixture was stirred at room temperature for 10 hours to obtain a pale yellow slurry. This slurry was separated by filtration, washed with methanol, and dried under reduced pressure at 180 ° C. for 8 hours to obtain 523 g of a pale yellow polyimide powder. The logarithmic viscosity of this polyimide powder is 0.52 dl / g, the glass transition temperature is 255 ° C, and the melting point is 378 ° C (DS
According to the C method. )Met.

The thermal stability of the polyimide obtained in this example was tested by changing the residence time in the cylinder of the flow tester and measuring the melt viscosity. Cylinder temperature is 420 ℃,
The pressure was 100 kg / cm ² . The results are shown in FIG. Even if the residence time in the cylinder becomes longer, the melt viscosity hardly changes, indicating that the thermal stability is good.

Comparative Example 1 A pale yellow polyimide powder was obtained in exactly the same manner as in Example 1, except that aniline was not used.

The logarithmic viscosity of the polyimide powder was 0.50 dl / g, the glass transition temperature was 255 ° C., and the melting point was 378 ° C. When the residence time in the flow tester cylinder was changed and the melt viscosity was measured in the same manner as in Example 1, the melt viscosity increased as the residence time became longer, and the thermal stability was higher than that of the polyimide obtained in Example 1. Was inferior. The results are shown in FIG.

Example 2 In exactly the same manner as in Example 1, except that 294 g (1.0 mol) of 3,3 ′, 4,4′biphenyltetracarboxylic dianhydride as a tetracarboxylic dianhydride and 4,4 ′ as a diamine compound were used.
49.6 g of 4'-bis (3-aminophenoxy) biphenyl
(0.950 mol), 11.16 g (0.1
2 mol) to obtain a polyimide powder. The logarithmic viscosity of the polyimide powder was 0.50 g / dl, and the glass transition temperature was 221 ° C. Using the polyimide powder obtained in this example, the melt viscosity was repeatedly measured using an orifice having a diameter of 0.1 cm and a length of 1 cm with a Koka type flow tester (CFT-500, manufactured by Shimadzu Corporation). Preheating time 5 minutes, 400 ℃, 100kg / c
Extruded at a pressure of m ² . Crush the obtained strand,
Further, the test of extruding under the same conditions was performed five times in succession. As a result, the melt viscosity at 400 ° C. was 28 times at 1, 2, 3, 4, and 5 repetitions, respectively.
The melt viscosity was 00, 2800, 2750, 2800, and 2800 poise, and even when the number of repetitions was increased, there was almost no change in the melt viscosity, and the melt molding stability was excellent.

〔The invention's effect〕

According to the method of the present invention, a polyimide having excellent mechanical properties, thermal properties, electrical properties, solvent resistance, heat resistance, heat stability for a long time, and excellent moldability is provided. can do.

[Brief description of the drawings]

FIG. 1 is an example showing the relationship between the residence time of a polyimide obtained in Example 1 and Comparative Example 1 in a flow tester cylinder and the melt viscosity.

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-61-143478 (JP, A) JP-A-62-68817 (JP, A) JP-A-62-86021 (JP, A) JP-A-59-1984 170122 (JP, A) JP 38-5997 (JP, B1)

Claims (2)

(57) [Claims] (1) General formula (I) (Wherein, Y ₁ , Y ₂ , Y ₃ and Y ₄ each independently represent a group selected from the group consisting of hydrogen, methyl group, methoxy group, chlorine and bromine.) B) General formula (II) (Where R is Represents a tetravalent group selected from the group consisting of A) a tetracarboxylic dianhydride represented by the general formula (III) Z-NH ₂ (III) (wherein Z is Represents a monovalent group selected from the group consisting of (D) the amount of aromatic diamine is 0.9 to 1.0 mole ratio per mole of tetracarboxylic dianhydride and the amount of aromatic monoamine is 1 mole of tetracarboxylic dianhydride; 0.01 to 0 per hit.
General formula (IV) to be reacted at 5 mole ratio Wherein Y ₁ , Y ₂ , Y ₃ , Y ₄ and R are the same as defined above, and the terminal of the polymer molecule is represented by the formula (IV-a) (Wherein R and Z are the same as described above). (2) General formula (I) (Wherein, Y ₁ , Y ₂ , Y ₃ and Y ₄ each independently represent a group selected from the group consisting of hydrogen, methyl group, methoxy group, chlorine and bromine). General formula (II) (Where R is Represents a tetravalent group selected from the group consisting of A) a tetracarboxylic dianhydride represented by the general formula (III) Z-NH ₂ (III) (wherein Z is Represents a monovalent group selected from the group consisting of (D) the amount of aromatic diamine is 0.9 to 1.0 mole ratio per mole of tetracarboxylic dianhydride and the amount of aromatic monoamine is 1 mole of tetracarboxylic dianhydride; 0.01 to 0 per hit.
General formula (IV) obtained by reacting at a molar ratio of 5 Wherein Y ₁ , Y ₂ , Y ₃ , Y ₄ and R are the same as defined above, and the terminal of the polymer molecule is represented by the formula (IV-a) (Wherein R and Z are the same as above), a polyimide having good thermal stability.