JP2558338B2 - Method for producing polyimide with good moldability - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a polyimide resin for melt molding. More specifically, it relates to a method for producing a polyimide having good thermal stability and excellent moldability.

[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.

Various polyimides having excellent characteristics have been developed so far.

However, even if it is excellent in heat resistance, it does not have a clear glass transition temperature, so when it is used as a molding material, it must be processed using a method such as sintering molding. In addition, 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 shown that a polyimide having the following formula (VI) as a polyimide having excellent mechanical properties, thermal properties, electrical properties, solvent resistance, etc. (In the formula, R'is 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 which is directly or cross-linked with each other. And a tetravalent group selected from the group consisting of non-fused polycyclic aromatic groups). (JP-A-1-9226 1-9227) The above-mentioned polyimide is a novel heat resistant resin having many good physical properties.

Since the above polyimide flows at high temperature, various melt moldings are possible, but on molding processing, it is desirable to develop a polyimide that shows good fluidity at lower temperature and further shows stable fluidity during molding processing. Has been done.

[Problems to be Solved by the Invention] An object of the present invention is to obtain a polyimide excellent in molding processability in addition to the excellent properties originally possessed by polyimide.

[Means for solving problems]

The present inventors achieved the present invention by conducting earnest research in order to solve the above problems. That is, the present invention is a reaction between diamine and tetracarboxylic dianhydride,
In the method for producing a polyimide in which the obtained polyamic acid is thermally or chemically imidized, (a) a diamine is represented by the following formula (I): A diamine represented by the following formula (II): (Where R is Represents a tetravalent group selected from ) Is a tetracarboxylic dianhydride, and (c) is further reacted by the following formula (III) (Wherein, Z _{is, -CH 2 -, - (CH} 2) 2 -, - (CH 2) 3 -, - (CH 2) 4
_{-, - (CH 2) 5} -, - (CH 2) 6 -, - (CH 2) 7 -,
- (CH _{2) 8} -, Represents a divalent group selected from the group consisting of ) In the presence of an aliphatic and / or alicyclic dicarboxylic acid anhydride, (d) the amount of tetracarboxylic dianhydride is 0.9 to 1.0 mole ratio per mole of diamine, and The amount of the dicarboxylic acid anhydride is 0.001 to 1.0 mol ratio per mol of the diamine. The following formula (IV) (Wherein R represents the same as above) and is a method for producing a polyimide having a good moldability, which comprises a repeating unit represented by the following formula.

The diamine represented by formula (I) used in the method of the present invention is bis {4- [4- (4-aminophenoxy) phenoxy] phenyl} sulfone.

In addition, there is no problem in substituting a part of the diamine with another diamine as long as the good physical properties of the polyimide of the method of the present invention are not impaired.

As a diamine that can be partially substituted,
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, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-amino Phenoxy) 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-bis [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, 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, 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,
These may be used alone or in combination of two or more.

The tetracarboxylic acid dianhydride represented by the formula (II) used in the method of the present invention includes, for example, ethylene tetracarboxylic acid dianhydride, butane tetracarboxylic acid dianhydride, cyclopentane tetracarboxylic acid dianhydride. Stuff,
Pyromellitic dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) ) Methane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-
Dicarboxyphenyl) propane dianhydride, 2,2-bis (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'-benzophenone tetracarboxylic acid dianhydride, 2,2', 3,3'-benzophenone tetracarboxylic 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, 4,4 '-(m-phenylenedioxy) diphthalic acid dianhydride, 2,3,6,7-naphthalente Lacarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid dianhydride, 1,2,3,4-benzenetetracarboxylic acid Dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride These tetracarboxylic acid dianhydrides may be used alone or in admixture of two or more.

Examples of the dicarboxylic acid monoanhydride represented by the formula (III) used in the method of the present invention include malonic acid anhydride, succinic acid anhydride, glutaric acid anhydride, adipic acid anhydride, pimelic acid anhydride, Suberic acid anhydride, azelaic acid anhydride, sebacic acid anhydride, methylmalonic acid anhydride, ethylmalonic acid anhydride, dimethylmalonic acid anhydride,
Methylsuccinic anhydride, 2,2-dimethylsuccinic anhydride, 2,3-dimethylsuccinic anhydride, tetramethylsuccinic anhydride, cyclohexanedicarboxylic acid anhydride, etc., and these aliphatic and / or alicyclic The dicarboxylic acid anhydrides may be used alone or in admixture of two or more.

In the present invention, the tetracarboxylic acid dianhydride represented by the formula (II) is added to 1 mole ratio of the diamine represented by the formula (I).
A 9-1.0 molar ratio was used, to which dicarboxylic anhydride 0.00
A polyamic acid obtained in the presence of a molar ratio of 1 to 1.0, preferably 0.01 to 0.5, can be obtained by thermal or chemical imidization, and the dicarboxylic acid anhydride used here has the characteristics of the present invention. Yes, the dicarboxylic acid anhydride directly or indirectly contributes to the reaction during the formation of the polyimide, plays a part of the constituent components of the polyimide or the catalytic action of the formation reaction of the polyimide, and obtains a highly processable polyimide. It plays a major role in That is, if the dicarboxylic acid anhydride content is less than 0.001 mol ratio, a polyimide having good processability cannot be obtained. On the contrary, if the dicarboxylic acid anhydride content is more than 1.0 mol ratio, a polyimide having good mechanical properties cannot be obtained.

The dicarboxylic acid anhydride can produce a polyimide having good processability in the presence of 0.001 to 1.0 molar ratio, in this case, the use ratio of the tetracarboxylic dianhydride and the diamine, which are the raw materials of the polyimide, is 1.0 mol of the diamine. Against the ratio
It is effective to use a tetracarboxylic dianhydride in a molar ratio of 0.9 to 1.0, and the polyimide having good thermal stability at high temperatures of the present invention cannot be obtained outside this range.

As described above, a polyimide is produced using tetracarboxylic dianhydride, diamine, and dicarboxylic anhydride, and in this case, all known production methods of polyimide can be used. That is, (i) a method in which a dicarboxylic acid anhydride is added and then the reaction is continued by adding a dicarboxylic acid anhydride, and (b) a dicarboxylic acid anhydride is added to the diamine and reacted, Addition of carboxylic acid dianhydride and further continuing the reaction, (c) addition of diamine, tetracarboxylic acid dianhydride, dicarboxylic acid anhydride at the same time, reaction, etc., any addition, reaction is allowed .

The reaction temperature is 0 ° C to 250 ° C, usually 60 ° C or lower.

 The reaction pressure is not particularly limited and can be carried out at normal pressure.

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

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

(Wherein R is the same as described above). The polyamic acid is dehydrated by heating to 100 to 400 ° C. or chemically imidized using a commonly used imidizing agent, for example, triethylamine and acetic anhydride. A corresponding polyimide comprising the repeating unit of IV) is obtained.

(In the formula, R is the same as described above.) Generally, after the polyamic acid is formed at a low temperature, the polyamic acid is further thermally or chemically imidized. 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, diamine, tetracarboxylic dianhydride, aromatic dicarboxylic acid anhydride is suspended or dissolved in an organic solvent and then reacted under heating to simultaneously generate polyamic acid and dehydrate imidize it. It is also possible to obtain a polyimide having a repeating unit of the above formula (IV).

In addition, tetracarboxylic dianhydride, diamine, dicarboxylic acid anhydride without using an organic solvent, after mixing the three in a powder state, a method of treating in the presence or absence of a chemical imidizing agent to a polyimide, etc. Can also be used.

When the polyimide of the present invention is subjected to melt molding, other thermoplastic resin within a range that does not impair the object of the present invention, for example,
Polyethylene, polypropylene, polycarbonate, polyarylate, polyamide, polysulfone, polyether sulfone, polyether ketone, polyphenylene sulfide, polyamide imide, polyether imide, modified polyphenylene oxide, etc. can be blended in appropriate amounts depending on the purpose. . Furthermore, the following fillers and the like used in ordinary resin compositions may be used to such an 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.

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

Example 1 616.7 g (1.0 mol) of bis {4- [4- (4-aminophenoxy) phenoxy] phenyl} sulfone was added to a reactor equipped with a stirrer, a reflux condenser and a nitrogen inlet tube.
Charge 5215 g of N, N-dimethylacetamide, add 207.1 g (0.95 mol) of pyromellitic dianhydride in portions at room temperature under a nitrogen atmosphere while paying attention to increase in solution temperature, and add at room temperature to
Stir for 20 hours. The polyamic acid thus obtained had an inherent viscosity of 0.56 dl / g. The logarithmic viscosity is N, N-dimethylacetamide as a solvent, concentration 0.5g / 100ml solvent, 35 ℃
It is the value measured in (the same applies below).

To this polyamic acid solution, 17.6 g (0.155 mol) of glutaric anhydride was added at room temperature under a nitrogen atmosphere, and the mixture was further stirred for 1 hour. Then, to this solution, 202 g (2 mol) of triethylamine and 306 g (3 mol) of acetic anhydride were added dropwise. About 2 hours after the completion of the dropping, yellow polyimide powder began to precipitate. After further stirring at room temperature for 20 hours, the reaction product was discharged into methanol and filtered. Further, it was dispersed and washed in methanol, filtered, and dried at 180 ° C. for 2 hours to obtain 779 g of polyimide powder. The glass transition temperature of this polyimide powder is 285.
C., melting point was 420.degree. C. (according to DSC. The same applies hereinafter).

Using the polyimide powder obtained in this example, a high-performance flow tester (Shimadzu Corporation, CFT-500, orifice diameter
The relationship between melt viscosity and pressure (shear rate) was measured at 0.1 cm and length of 1 cm. FIG. 1 shows the relationship between the melt viscosity and the shear rate measured at various shear rates after being kept at a temperature of 440 ° C. for 5 minutes.

Comparative Example 1 774 g of polyimide powder was obtained in exactly the same manner as in Example 1, but without performing the operation of reacting glutaric anhydride.

Using this polyimide powder, the relationship between melt viscosity and shear rate was determined by a flow tester as in Example 1. FIG.
The results are shown in.

Example 2 616.7 g of bis {4- [4- (4-aminophenoxy) phenoxy] phenyl} sulfone was placed in the same apparatus as in Example 1.
(1.0 mol) and 5160 g of dimethylacetamide were charged, and under a nitrogen atmosphere at room temperature, 15.4 g (0.1 mol) of 1,2-cyclohexanedicarboxylic acid anhydride and 279.3 g (0.95 mol) of 3,
3 ', 4,4'-biphenyltetracarboxylic dianhydride,
The mixture was added while paying attention to the rise in solution temperature, and the mixture was stirred at room temperature for about 20 hours. The logarithmic viscosity of the obtained polyamic acid was 0.51.

Then 202 g (2 mol) of triethylamine and 306 g (3 mol) of acetic anhydride were added dropwise to this solution. Stir for 20 hours to obtain a pale yellow slurry. The slurry was filtered, washed with methanol, and dried under reduced pressure at 180 ° C. for 8 hours.
50 g of pale yellow polyimide powder was obtained. The glass transition temperature of this polyimide powder was 261 ° C.

The molding stability of the polyimide obtained in this example was measured by changing the residence time in the cylinder of the flow tester. The temperature was 380 ° C. and the pressure was 100 kg / cm ² . The results are shown in FIG. It can be seen that even if the residence time in the cylinder becomes long, the melt viscosity hardly changes and the thermal stability is good.

Comparative Example 2 A light yellow polyimide powder was obtained in exactly the same manner as in Example 2, except that 1,2-cyclohexanedicarboxylic acid anhydride was not used.

The glass transition temperature of the polyimide powder was 261 ° C. When the melt viscosity was measured by changing the residence time in the flow tester cylinder in the same manner as in Example 2, the melt viscosity increased as the residence time became longer, and the thermal stability was higher than that of the polyimide obtained in Example 2. Was inferior.

〔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, thermal stability for a long time, and excellent moldability is provided. can do.

[Brief description of drawings]

FIG. 1 shows a high-performance flow tester (CFT-500, Shimadzu Corporation, CFT-500, orifice diameter 0.1 cm, length 1) using the polyimide powder of the present invention of Example 1 and the polyimide powder of Comparative Example 1.
is a curve diagram of the result of measuring the relationship between melt viscosity and pressure (shear rate) in cm, and after maintaining the temperature at 440 ° C. for 5 minutes,
The shear rate was variously changed and measured. FIG. 2 is a curve diagram in which, in order to compare the molding stability of the polyimide powders in Example 2 and Comparative Example 2 of the present invention, the melt viscosity was measured by changing the residence time in the cylinder of the flow tester and compared. Yes, the measurement temperature is 380 ° C, and the measurement pressure is 100 kg / cm ² .

Claims (1)

(57) [Claims] 1. A method for producing a polyimide in which a diamine is reacted with tetracarboxylic dianhydride to thermally or chemically imidize the resulting polyamic acid, wherein (a) the diamine is represented by the following formula (I): A diamine represented by the following formula (II): "R is Represents a tetravalent group selected from ) Is a tetracarboxylic dianhydride, and (c) the reaction formula is represented by the following formula (III) (Wherein, Z is _{-CH 2 -, - (CH 2} ) 2 -, - (CH 2) 3 -, - (CH 2) 4
_{-, - (CH 2) 5} -, - (CH 2) 6 -, - (CH 2) 7 -,
- (CH _{2) 8} -, Represents a divalent group selected from the group consisting of In the presence of a dicarboxylic acid anhydride represented by the formula (4), (d) the amount of the tetracarboxylic acid dianhydride is 0.9 to 1.0 mol ratio per mol of the diamine, and the amount of the dicarboxylic acid anhydride is the diamine. The following formula (IV) in which the molar ratio is 0.001 to 1.0 per mole (In the formula, R represents the same as the above.) A method for producing a polyimide having a good moldability, which comprises a repeating unit represented by the formula.