JP2596565B2 - 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 diamine have high heat resistance, excellent mechanical strength, dimensional stability, flame retardancy, electrical insulation, etc. It is used in fields such as aerospace equipment and transportation equipment, and is expected to be widely used in fields where co-heat resistance is required in the future.

Conventionally, various polyimides exhibiting excellent characteristics have been developed. However, even if it has excellent 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, and it has excellent workability. It has a low glass transition temperature, is soluble in halogenated hydrocarbons, 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). (Wherein, X represents a group selected from the group consisting of a direct bond, a divalent hydrocarbon group having 1 to 10 carbon atoms, a hexafluorinated isopropylidene group, a carbonyl group, a thio group and a sulfonyl group; ₁ , Y ₂ , Y ₃ and Y ₄ each independently represent a group selected from the group consisting of hydrogen, lower alkyl group, lower alkoxy group, chlorine and bromine, and R represents an aliphatic group having 2 or more carbon atoms, Selected from the group consisting of a cycloaliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, and a non-condensed polycyclic aromatic group in which the aromatic groups are directly or interconnected by a bridge member A polyimide having a repeating unit represented by the following formula: (JP-A-61-143478, 62
-68817, 62-86021, JP-A-62-235381, 63-1280
25). The above-mentioned polyimide is a novel heat-resistant resin having many good physical properties.

However, the above-mentioned polyimide shows excellent fluidity, and although it is a polyimide having good processability, if it is kept at a high temperature for a long time (for example, during injection molding, if it is kept at a high temperature for a long time in a cylinder, etc., ) 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 provides: (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): (Where Z is Represents a divalent group selected from the group consisting of (D) the amount of tetracarboxylic dianhydride is 0.9 to 1.0 mole ratio per mole of diamine, and the amount of dicarboxylic anhydride is 0.01 to 0.5 mole per mole of diamine. General formula (IV) obtained by reacting 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 Y ₁ , Y ₂ , Y ₃ , Y ₄ 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 ',
5,5'-tetrachlorobiphenyl, 4,4'-bis (3-aminophenoxy) -3,3'-dibromobiphenyl, 4,4 '
-Bis (3-aminophenoxy) -3,5-dibromobiphenyl, 4,4'-bis (3-aminophenoxy) -3,
3 ', 5,5'-Tetrabromobiphenyl may be used, and these may be used alone or as a mixture 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 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
-Aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] butane,
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-bis [4- (3-aminophenoxy) benzoyl] benzene, 1,3-bis [4- (3-aminophenoxy) benzoyl] benzene, bis [4- (3 -Aminophenoxy)
Phenyl] methane, 1,1-bis [4- (3-aminophenoxy) phenyl] ethane, 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-amino Phenoxy) -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-phenylenedioxy) diphthalic acid dianhydride Anhydride, 4,4 '-(m-phenylenedioxy) diphthalic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride Anhydride, 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-phenanthrenetetracarboxylic dianhydride.These tetracarboxylic dianhydrides may be used alone or in combination of two or more. Used.

The dicarboxylic anhydride represented by the formula (III) used in the method of the present invention includes, for example, phthalic anhydride,
2,3-benzophenone dicarboxylic anhydride, 3,4-benzophenone dicarboxylic anhydride, 2,3-dicarboxyphenyl phenyl ether anhydride, 3,4-dicarboxyphenyl phenyl ether anhydride, 2,3-biphenyl dicarboxylic acid Acid anhydride, 3,4-biphenyldicarboxylic anhydride,
2,3-dicarboxyphenylphenyl sulfone anhydride,
3,4-dicarboxyphenylphenylsulfone anhydride,
2,3-dicarboxyphenylphenyl sulfide anhydride, 3,4-dicarboxyphenyl phenyl sulfide anhydride, 1,2-naphthalenedicarboxylic anhydride, 2,3-naphthalenedicarboxylic anhydride, 1,8-naphthalenedicarboxylic acid Acid anhydride, 1,2-anthracene dicarboxylic anhydride,
Examples thereof include 2,3-anthracene dicarboxylic anhydride and 1,9-anthracene dicarboxylic anhydride, which may be used alone or as a mixture of two or more.

The molar ratio of the diamine, tetracarboxylic dianhydride and dicarboxylic anhydride used in the method of the present invention is such that tetracarboxylic dianhydride is
0.9 to 1.0 mol, and the dicarboxylic anhydride is 0.001 to 1.0 mol.

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

The co-existing dicarboxylic anhydride is used in an amount of 0.001 to 1.0 mole ratio to the diamine. 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 organic solvent in the method of the present invention, starting material diamine, tetracarboxylic dianhydride, added dicarboxylic anhydride,
The reaction method is as follows: (a) a method in which a diamine is reacted with a tetracarboxylic dianhydride, and then a dicarboxylic acid anhydride is added to continue the reaction; and (b) a dicarboxylic acid anhydride is added to the diamine to cause a reaction. Then, tetracarboxylic dianhydride is added and the reaction is further continued. (C) Diamine, tetracarboxylic dianhydride and dicarboxylic anhydride are simultaneously added and reacted. It doesn't hurt.

The reaction temperature is from 0 ° C to 250 ° C. Usually, it is performed at a temperature of 60 ° 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 diamine, tetracarboxylic dianhydride, dicarboxylic anhydride, type of solvent and reaction temperature used, 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.

(Wherein Y ₁ , Y ₂ , Y ₃ , Y ₄ and R are the same as above) Generally, after polyamic acid is formed at a low temperature, it is further thermally or chemically imidized. Is performed. 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, tetracarboxylic dianhydride, diamine, dicarboxylic anhydride suspended or dissolved in an organic solvent and then reacted under heating, the polyamic acid generation and dehydration imidization are performed simultaneously, the above formula A polyimide comprising the repeating unit (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 materials such as boron fiber, silicon carbide fiber, carbon whisker, asbestos, metal fiber, ceramic fiber, flame retardant improver such as antimony trioxide, magnesium carbonate and calcium carbonate, and electric property improver 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 1 368 g (1.0 mol) of 4,4-bis (3-aminophenoxy) biphenyl and 5,5 N, N-dimethylacetamide were placed in a reaction vessel equipped with a stirrer, a reflux condenser, and a nitrogen inlet tube.
215 g was inserted, and at room temperature under a nitrogen atmosphere, 211.46 g (0.97 mol) of pyromellitic dianhydride was added in portions while paying attention to the rise in solution temperature, and the mixture was stirred at room temperature for about 20 hours.

To this polyamic acid solution, 22.2 g (0.15 mol) of phthalic anhydride was added at room temperature under a nitrogen atmosphere, and the mixture was further stirred for 1 hour. Then, 404 g (4 mol) of triethylamine and 306 g (3 mol) of acetic anhydride were added dropwise to the solution. About one hour after the completion of the dropping, yellow polyimide powder began to precipitate. The mixture was further stirred at room temperature for 10 hours and filtered. Further, the mixture was dispersed and washed in methanol, filtered and dried at 180 ° C. for 2 hours to obtain 536 g of a polyimide powder. This polyimide powder had a glass transition temperature of 256 ° C. and a melting point of 378 ° C. (according to DSC; the same applies hereinafter). The logarithmic viscosity of this polyimide powder is
It was 0.53 dl / g. Here, the logarithmic viscosity uses a mixed solvent of parachlorophenol: phenol (weight ratio 90:10),
It is a value measured at 35 ° C with a solvent of concentration 0.5g / 100ml.

Using the polyimide powder obtained in this example, with a Koka type flow tester (CFT-500, manufactured by Shimadzu Corporation), a diameter of 0.1 c
The melt viscosity was repeatedly measured using an orifice having a length of 1 cm and a length of 1 cm. After keeping at 420 ℃ for 5 minutes, 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.

FIG. 1 shows the relationship between the number of repetitions and the melt viscosity. Even if the number of repetitions increases, there is almost no change in the melt viscosity, indicating that the thermal stability is good.

Comparative Example 1 529 g of a polyimide powder was obtained in exactly the same manner as in Example 1 except that the operation of reacting phthalic anhydride was not performed.

The logarithmic viscosity of the obtained polyimide powder was 0.52 dl / g. Using this polyimide powder, a repeated test of the melt viscosity was performed by a flow tester in the same manner as in Example 1, and the results shown in FIG. 1 were obtained.

As the number of repetitions increased, the melt viscosity increased, and the thermal stability was inferior to that of the polyimide obtained in Example 1.

Example 2 In exactly the same manner as in Example 1, except that 4,4'-bis (3-aminophenoxy) biphenyl 3
68 g (1.0 mol), 3,3 as tetracarboxylic dianhydride
3 ', 4,4'-biphenyltetracarboxylic dianhydride 279.3
g (0.95 mol) and 22.2 g (0.15 mol) of phthalic anhydride as a dicarboxylic anhydride were used 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. The molding stability of the obtained polyimide was measured by changing the residence time in the cylinder of the flow tester. The temperature was 400 ° C. and the pressure was 100 kg / cm ² . The retention time was 2800 poise after 5 minutes, and 2800 poise after 30 minutes. There was almost no increase in melt viscosity, and the melt molding stability was excellent.

〔The invention's effect〕

According to the present invention, there is provided a polyimide which is excellent in mechanical properties, thermal properties, electrical properties, solvent resistance, heat resistant, thermally stable for a long time, and excellent in moldability. Can be.

[Brief description of the drawings]

FIG. 1 is an example showing the relationship between the number of times of repetition of melting of the polyimide obtained in Example 1 and Comparative Example 1 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). 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): (Where Z is Represents a divalent group selected from the group consisting of (D) the amount of tetracarboxylic dianhydride is 0.9 to 1.0 mole ratio per mole of diamine, and the amount of dicarboxylic anhydride is 0.01 to 0.5 mole per mole of diamine. General formula (IV) 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 Y ₁ , Y ₂ , Y ₃ , Y ₄ 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): (Where Z is Represents a divalent group selected from the group consisting of (D) the amount of tetracarboxylic dianhydride is 0.9 to 1.0 mole ratio per mole of diamine, and the amount of dicarboxylic anhydride is 0.01 to 0.5 mole per mole of diamine. General formula (IV) obtained by reacting 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 Y ₁ , Y ₂ , Y ₃ , Y ₄ and Z are the same as above), a polyimide having good thermal stability.