JP2557914B2 - Method for producing polyimide with good moldability - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to melt molding, and more particularly to a method for producing a polyimide having 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 already shown that the polyimide of formula (I) has excellent mechanical properties, thermal properties, electrical properties, solvent resistance and the like and has heat resistance. (In the formula, 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, or a sulfonyl group, Y ₁ , Y ₂ , Y ₃ and Y ₄ each represent a group selected from the group consisting of hydrogen, a lower alkyl group, a lower alkoxy group, chlorine or bromine, and R represents an aliphatic group having 2 or more carbon atoms, a ring. 4 selected from the group consisting of an aliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, and a non-condensed polycyclic aromatic group in which the aromatic groups are connected to each other directly or by a bridging member. The present invention has found a polyimide having a repeating unit represented by the formula (1). (JP-A-61-143478, JP-A-62-68817, JP-A-62-86021,
62-235381, 63-128025, etc.). The above polyimide is a novel heat resistant resin having many good physical properties.

However, since the above polyimide flows at high temperature, various melt molding is possible, but in molding processing,
There is a demand for the development of a polyimide that has good fluidity at lower temperatures and that exhibits stable fluidity during molding.

[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]

As a result of earnest research for solving the above problems, the present inventors have shown the following formula (I). In the formula, X is a direct bond, a —CH ₂ — group, Represents a group selected from the group consisting of —CO— group, —S— group and —SO ₂ — group, wherein Y ₁ , Y ₂ , Y ₃ and Y ₄ are hydrogen, methyl group, methoxy group, chlorine and bromine, respectively. Represents a group selected from the group consisting of Represents a tetravalent group selected from the group consisting of ) In the method for producing a polyimide consisting of repeating units, the following formula (II) (In the formula, R is the same as above) 1.0 molar ratio of tetracarboxylic dianhydride and the following formula (III) (Wherein X, Y ₁ , Y ₂ , Y ₃ and Y ₄ are the same as above)
The following formula (IV) Z-NH ₂ (IV) (wherein Z is a methyl group, an ethyl group, an n-propyl group,
Isopropyl group, n-butyl group, isobutyl group, sec-
Butyl group, tert-butyl group, n-amyl group, isoamyl group, tert-amyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group ,
It is a group selected from a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclohexylmethyl group. The method for producing a polyimide is characterized in that the polyamic acid obtained in the presence of 0.001 to 1.0 molar ratio of the monoamine represented by the formula (1) is thermally or chemically imidized.

Examples of the etherdiamine having the formula (III) as a raw material for producing the polyimide of the present invention include 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'-tetra Bromobiphenyl, 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 can be mentioned, and these can be used alone or in admixture 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, a part of the above diamine may be used in place of the diamine used in other known polyimides.

The tetracarboxylic dianhydride represented by the formula (II), for example, ethylene tetracarboxylic dianhydride,
Butanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, 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 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 dianhydride, 4, 4 '-(m-phenylenedioxy) diphthalic 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
-Anthracene tetracarboxylic dianhydride, 1,2,7,8-
Such as phenanthrene tetracarboxylic dianhydride,
These tetracarboxylic dianhydrides are used alone or in combination of two or more.

Examples of the monoamine represented by the formula (IV) include methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, tert-butylamine,
n-amylamine, isoamylamine, tert-amylamine, hexylamine, heptylamine, octylamine, 2-ethylhexylamine, nonylamine, decylamine, vinylamine, allylamine, cyclopropylamine, cyclobutylamine, cyclopentylamine,
Cyclohexylamine, cycloheptylamine, cyclooctylamine, cyclohexanemethylamine, etc. These aliphatic amines and / or alicyclic monoamines may be used alone or in admixture of two or more.

In the present invention, an ether diamine having the formula (III) in a molar ratio of tetracarboxylic dianhydride having the formula (II) is 0.9
˜1.0 molar ratio to which a polyamine obtained in the presence of 0.001 to 1.0 molar ratio of monoamine, preferably 0.01 to 0.5 molar ratio, can be obtained by thermal or chemical imidization and is used here. The monoamine has a feature of the present invention, and the monoamine directly or indirectly contributes to the reaction at the time of forming the polyimide, plays a part of the constituent components of the polyimide or the catalytic action of the reaction for forming the polyimide, and has a processability. It plays a major role in obtaining a good polyimide. That is, a polyimide having a good processability cannot be obtained with a monoamine content of 0.001 mol ratio or less, and conversely, a polyimide having good mechanical properties cannot be obtained with a monoamine content of 1.0 mol ratio or more.

Although it is possible to produce a polyimide having good processability in the presence of 0.001 to 1.0 molar ratio of monoamine, the use ratio of tetracarboxylic dianhydride and ether diamine, which are raw materials of the polyimide, is tetracarboxylic dianhydride. 1.0
The use of an etherdiamine 0.9 to 1.0 ratio with respect to the molar ratio is effective, and a 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 etherdiamine, tetracarboxylic dianhydride and monoamine, and in this case, all known production methods of polyimide can be used.
That is, (1) ether diamine, tetracarboxylic acid dianhydride, monoamine three are dissolved in an organic solvent (for example, N, N-dimethylacetamide, N, N-dimethylformamide and the like used for ordinary polyimide), After forming an amic acid, a method of treating the compound in the presence or absence of a chemical imidizing agent (eg, triethylamine, acetic anhydride, etc.) to obtain a polyimide, (2) ether diamine, tetracarboxylic acid dianhydride as an organic solvent After dissolution, a monoamine is added to form an amic acid, and then treated in the presence or absence of a chemical imidizing agent to form a polyimide,
(3) After dissolving tetracarboxylic dianhydride and monoamine in an organic solvent, ether diamine is added to form an amic acid, and then treated in the presence or absence of a chemical imidizing agent to form a polyimide. Method (4) A method in which etherdiamine, tetracarboxylic dianhydride, monoamine, and three are mixed in a powder state without using an organic solvent, and then treated in the presence or absence of a chemical imidizing agent to form a polyimide. Etc. Normally, the temperature for making amic acid is 0 ° C to 250 ° C.
The temperature at which the amic acid is thermally imidized is preferably 100.
C to 400 C is preferred. By any of the above methods, a polyimide having good fluidity at high temperature, which is a feature of the present invention, can be obtained.

When subjecting the polyimide of the present invention to melt molding, other thermoplastic resins within the range not impairing the object of the present invention, such as polyethylene, polypropylene, polycarbonate,
Polyarylate, polyamide, polysulfone, polyethersulfone, polyetherketone, polyetheretherketone, polyphenylene sulfide, polyamideimide, polyetherimide, modified polyphenylene oxide and the like can be added in an appropriate amount according to the purpose. Further, the following fillers used in ordinary resin compositions may be used to the extent that the object of the invention is not impaired. That is, graphite, carbon tandem, silica powder, molybdenum disulfide, wear resistance improving materials such as fluororesin, glass fiber, carbon fiber, polon fiber, silicon carbide fiber, carbon whiskers, asbestos, metal fibers, ceramic fibers, etc. reinforcement Wood, antimony trioxide,
Flame retardant improver such as magnesium carbonate and calcium carbonate, electrical property improver such as clay and mica, tracking resistance improver such as asbestos, silica and graphite, acid resistance improver such as barium sulfate, silica and calcium metasilicate , Thermal conductivity improvers such as iron powder, zinc powder, aluminum powder, copper powder, and other glass beads, glass spheres, talc, diatomaceous earth, alumina, silasbaln, hydrated alumina, metal oxides, colorants, etc. .

〔Example〕

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

Example 1 A reaction vessel equipped with a stirrer, a reflux condenser and a nitrogen inlet tube was charged with benzophenonetetracarboxylic dianhydride 32.
2g (1.0mol) and N, N-dimethylacetamide as solvent
Charge 4050g, and under a nitrogen atmosphere at room temperature 4,4'-bis (3
-Aminophenoxy) diphenyl sulfide 392 g (0.98
Mol) while paying attention to the rise of the solution temperature,
Stir for 20 hours.

8.10 g of n-hexylamine was added to this polyamic acid solution.
(0.08 mol) was added, and the mixture was further stirred for 1 hour. Then 202 g (2 mol) of triethylamine and 306 g were added to this solution.
(3 mol) acetic anhydride was added dropwise. Stirring was continued 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 to obtain 661 g of a pale yellow polyimide powder. The glass transition temperature of this polyimide powder was 205 ° C (by DSC measurement. The same applies hereinafter), and the inherent viscosity was 0.62 dl / g. Here, the logarithmic viscosity is a value measured by dissolving in a mixed solvent of parachlorophenol / phenol (weight ratio 90/10) at a concentration of 0.5 g / 100 ml-solvent by heating and then cooling to 35 ° C.

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, which were measured by changing the shear rate after keeping the temperature at 320 ° C. for 5 minutes.

Comparative Example 1 652 g of a pale yellow polyimide powder was obtained in the same manner as in Example 1 except that n-hexylamine was not used. The polyimide powder obtained had an inherent viscosity of 0.62 dl / g.

Using this polyimide powder, the melt viscosity was measured with a flow tester in the same manner as in Example 1, and the results shown in FIG. 1 were obtained.

Example 2 218 g of pyromellitic dianhydride in the same apparatus as in Example 1
(1.0 mol) and N, N-dimethylacetamide (3830 g) were charged, cyclohexylamine (5.95 g, 0.06 mol) was added, and the mixture was stirred for about 20 minutes. Next, 357 g (0.97 mol) of 4,4- (3-aminophenoxy) biphenyl was added while paying attention to the rise of the solution temperature, and the mixture was stirred at room temperature for about 10 hours. To this solution 202 g (2 mol) triethylamine and 255 g
(2.5 mol) acetic anhydride was added dropwise and stirred at room temperature for 10 hours to obtain a pale yellow slurry. This slurry was filtered, washed with methanol, and dried under reduced pressure at 180 ° C for 8 hours to give 523g.
To obtain a pale yellow polyimide powder.

This polyimide powder has a glass transition temperature of 252 ° C and a melting point of 3
The inherent viscosity was 0.52 dl / g at 78 ° C.

As for the obtained polyimide, a Koka flow tester was used as in Example 1, and the cylinder temperature was 420 ° C. and the residence time was 5
The melt viscosity measured at a pressure of 100 / cm ² per minute was 2600 poise.

Further, the thermal stability of this polyimide was tested by changing the residence time in the cylinder of the flow tester and measuring the change in melt viscosity. The cylinder temperature is 420 ° C and the pressure during measurement is 100 kg / cm ² . 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 2 Example 2 except that cyclohexylamine was not used.
In the same manner as above, a pale yellow polyimide powder was obtained. The glass transition temperature of the polyimide powder was 255 ° C, the melting point was 378 ° C, and the inherent viscosity was 0.50 dl / g. The melt viscosity measured in the same manner as in Example 2 at a flow tester / cylinder temperature of 420 ° C., a residence time of 5 minutes and a pressure of 100 / cm ² was 3800 poise.

The thermal stability was determined by changing the residence time in the cylinder of the flow tester and measuring the melt viscosity. The melt viscosity increased as the residence time increased, and the heat stability was higher than that of the polyimide obtained in Example 2. It was inferior in sex. Results are shown in FIG.

Example 3 218 g of pyromellitic dianhydride in the same position as in Example 1
(1.0 mol), 2,2-bis {4- (3-aminophenoxy) phenyl} propane 393.6 g (0.96 mol) and n-
Octylamine 10.34 g (0.08 mol) was charged together with 3460 g of m-cresol, and the temperature was gradually raised by heating while stirring under a nitrogen atmosphere. After stirring at 150 ℃ for 3 hours,
Filtration gave a polyimide powder. After washing this polyimide powder once with methanol and acetone, 180 ℃
After vacuum drying for 8 hours, 560 g of polyimide powder was obtained. The polyimide powder had an inherent viscosity of 0.56 dl / g and a glass transition temperature of 228 ° C. Melt viscosity was measured by a flow tester at a temperature of 360 ° C. in the same manner as in Example 1.

 The results are shown in FIG.

Comparative Example 3 In the same manner as in Example 3 except that n-octylamine was not used, logarithmic viscosity 0.56 dl / g, glass transition temperature 231 ° C.
The polyimide of was obtained.

The same measurement as in Example 1 was performed at 360 ° C. The result is the third
Shown in the figure.

〔The invention's effect〕

According to the method of the present invention, it is possible to provide a polyimide having excellent mechanical properties, thermal properties, electrical properties, solvent resistance, excellent moldability, and thermal stability for a long time.

[Brief description of drawings]

1 and 3 show the relationship between the melt viscosity (poise) and shear rate of the polyimide of the present invention, and FIG. 2 shows an example of the relationship between the residence time in the flow tester / cylinder and the melt viscosity of the polyimide of the present invention. Is.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 61-143473 (JP, A) JP 59-170122 (JP, A) JP 61-291669 (JP, A) JP 62- 68817 (JP, A) JP 62-86021 (JP, A) JP 62-270636 (JP, A) JP 62-235381 (JP, A) JP 38-5997 (JP, B1)

Claims (1)

(57) [Claims] 1. The following formula (I) In the formula, X is a direct bond, a —CH ₂ — group, Represents a group selected from the group consisting of —CO— group, —S— group and —SO ₂ — group, wherein Y ₁ , Y ₂ , Y ₃ and Y ₄ are hydrogen, methyl group, methoxy group, chlorine and bromine, respectively. Represents a group selected from the group consisting of Represents a tetravalent group selected from the group consisting of ) In the method for producing a polyimide consisting of repeating units, the following formula (II) (In the formula, R is the same as above) 1.0 molar ratio of tetracarboxylic dianhydride and the following formula (III) Use _{(wherein, X, Y 1, Y 2} , Y 3, and Y ₄ are as defined above) with 0.9 to 1.0 molar ratio ether diamine represented by,
The following formula (IV) Z-NH ₂ (IV) (wherein Z is a methyl group, an ethyl group, an n-propyl group,
Isopropyl group, n-butyl group, isobutyl group, sec-
Butyl group, tert-butyl group, n-amyl group, isoamyl group, tert-amyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group ,
It is a group selected from a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclohexylmethyl group. ) The polyamic acid obtained in the presence of 0.001 to 1.0 molar ratio of the monoamine is thermally or chemically imidized to produce a polyimide.