JPH02160829A - Production of polyimide of good moldability - Google Patents

Abstract

PURPOSE:To obtain the title polyimide improved in heat stability and moldability by imidating a polyamic acid obtained by reacting a specified diamine with a tetracarboxylic acid dianhydride in the presence of a dicarboxylic acid anhydride. CONSTITUTION:1mol of a diamine of formula I is reacted with 0.9-1.0mol of a tetracarboxylic acid dianhydride of formula II (wherein R is a tetravalent group selected from among a 2C or higher aliphatic group, a cycloaliphatic group, a monocyclic aromatic group, a fused epicyclic aromatic ring and a noncondensed polycyclic aromatic group composed of aromatic groups bonded directly or through bridging members) at 0-250 deg.C for 4-24hr in the presence of a dicarboxylic acid anhydride of formula III (wherein Z is a bivalent group comprising a 1-10C aliphatic group and/or a cycloaliphatic group) to obtain a polyamic acid having a repeating units of formula IV as basic skeletons. This polyamic acid is imidated through dehydration by heating or by reaction with an imidating agent to obtain a polyimide having repeating units of formula V as basic skeletons.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a polyimide resin for melt molding.

More specifically, the present invention relates to a method for producing polyimide having good thermal stability and excellent moldability.

[Prior art] Polyimide, which is traditionally obtained by the reaction of tetracarboxylic dianhydride and diamine, has not only high heat resistance, but also excellent mechanical strength and dimensional stability, as well as flame retardancy and electrical insulation properties. It is used in fields such as electrical and electronic equipment, aerospace equipment, and transportation equipment, and is expected to be widely used in fields that require heat resistance in the future.

Various polyimides have been developed that exhibit superior properties.

However, even if it has excellent heat resistance, it does not have a clear glass transition temperature, so it must be processed using methods such as sintering when used as a molding material, and although it has excellent processability, it does not have a clear glass transition temperature. , low glass transition temperature,
Moreover, it is soluble in halogenated hydrocarbons, and its performance has both advantages and disadvantages, such as unsatisfactory heat resistance and solvent resistance.

On the other hand, the present inventor first developed a polyimide of the following formula (IV) (wherein R is the same as above) as a polyimide having excellent mechanical properties, thermal properties, electrical properties, solvent resistance, etc., and having heat resistance. We have discovered a polyimide having a repeating unit represented by (Japanese Patent Application No. 62-076095). The above polyimide is a new heat-resistant resin that has many good physical properties.

The above polyimide fluidizes at high temperatures, making it possible to perform various types of melt molding, but in terms of molding, there is a need to develop polyimides that have good fluidity at lower temperatures and also exhibit stable fluidity during molding. has been done.

[Problem that the invention seeks to solve]

An object of the present invention is to provide an excellent polyimide which not only has the excellent properties originally possessed by polyimide but also has good thermal stability and whose moldability does not deteriorate even when kept at high temperatures for a long period of time.

[Means for solving problems]

The present inventors conducted extensive research to solve the above problems and achieved the present invention. That is, the present invention provides a method for producing polyimide in which diamine and tetracarboxylic dianhydride are reacted and the obtained polyamic acid is thermally or chemically imidized, wherein (i) the diamine has the following formula (I). ), and (b) the tetracarboxylic dianhydride is represented by the following formula (II) (wherein R is an aliphatic group having 2 or more carbon atoms, a cycloaliphatic group, a monocyclic aromatic group) , a fused polycyclic aromatic group, and a tetravalent group selected from the group consisting of a non-fused polycyclic aromatic group in which aromatic groups are interconnected directly or through a bridge member. It is a carboxylic dianhydride, and (c)
Furthermore, the reaction is represented by the following formula (lI[) 0 (■) (wherein, Z represents a divalent group consisting of an aliphatic group and/or a cycloaliphatic group having 1 to 10 carbon atoms.) (d) The amount of tetracarboxylic dianhydride is 0.9 to 1.0 molar ratio per 1 mole of diamine, and the amount of dicarboxylic acid anhydride is in the presence of diamine. The molar ratio is 0.001 to 1.0 per mole.

(In the formula, R represents the same as defined above.) This is a method for producing a polyimide having good moldability and having a repeating unit represented by the following as a basic skeleton.

The diamine represented by formula (I) used in the method of the present invention is bis+4-(3-(4-aminophenoxy)benzoyl]phenyl)ether.

Note that there is no problem in replacing some of the above diamines with other diamines as long as the good physical properties of the polyimide used in the method of the present invention are not impaired.

Examples of diamines that can be used as partial substitutes include m-phenylenediamine, 0-phenylenediamine, ρ-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-bisC4-<4-aminophenoxy)phenyl]propane, 2,2-bis[4-(
4-aminophenoxy)phenylcobutane, 2,2-bis(4-(4aminophenoxy)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)phenylkoketone, 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,
BisC4-(3-aminophenoxy)phenylcomethane, 1,1-bis(4-(3-aminophenoquin)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)-ILl, 3.3.3-hexafluoropropane, 4 .4''-bis(3-aminophenoxy)biphenyl, 4.4'-bis(3-aminophenoxy)-3-methylbiphenyl, 44''-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-aminophenoquine) -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", 5,5tetrabromobiphenyl,
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, etc., and these may be used alone or in combination of two or more.

In addition, examples of the tetracarboxylic dianhydride represented by formula (n) used in the method of the present invention include ethylenetetracarboxylic dianhydride, butanetetracarboxylic dianhydride, and cyclopentanetetracarboxylic dianhydride. pyromellitic dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl) ) Methani dianhydride, 2,2-bis(
3,4-dicarboxyphenyl)propanihydride, 2
゜2-bis(2,3-dicarboxyphenyl)propanide anhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropanide anhydride , 2.2-bis(2,3-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropanihydride, 3.3°, 4.4'-benzophenone tetracarpon Acid dianhydride, 2.2', 3.3'-benzophenonetetracarboxylic dianhydride, 3.3',
4.4'-biphenyltetracarboxylic dianhydride, 2.
2', 3.3 biphenyltetracarboxylic dianhydride,
Bis(34-dicarboxyphenyl)ether dianhydride, bis(2,3-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, 4.4'-(P-phenylene dianhydride) oxy)cyphthalic dianhydride, 4.4'-(m-phenylenedioxy)cyphthalic dianhydride, 2,3,6.7-naphthalenetetracarboxylic dianhydride, 1.4.5.8 naphthalene Tetracarboxylic dianhydride, 1,2.5.6-naphthalenetetracarboxylic dianhydride, 1,2.34-benzenetetracarboxylic dianhydride, 3,4,910-perylenetetracarboxylic dianhydride , 2.3,6゜7-anthracenetetracarboxylic dianhydride, 1゜2.7.8-phenanthrenetetracarboxylic dianhydride, etc., and these tetracarboxylic dianhydrides may be used alone or in combination of two or more kinds. It is used as

Further, the dicarboxylic acid anhydride represented by the formula (I[l) used in the method of the present invention includes, for example, malonic anhydride, succinic anhydride, glutamic anhydride, adipic anhydride, pimelic anhydride, superric anhydride, Azelaic anhydride, sebacic anhydride, methylmalonic anhydride, ethylmalonic anhydride, dimethylmalonic anhydride, methylsuccinic anhydride,
2,2-dimethylsuccinic anhydride, 2,3-dimethylsuccinic anhydride, tetramethylsuccinic anhydride, maleic anhydride, citraconic anhydride, glutaconic anhydride, methylenesuccinic anhydride, allylmalonic anhydride, terraconic anhydride, anhydride These include muconic acid, cyclobutanedicarboxylic anhydride, cyclohexanedicarboxylic anhydride, cyclohexenedicarboxylic anhydride, camphoric anhydride, and these aliphatic and/or alicyclic dicarboxylic anhydrides may be used alone or in combination of two or more. It is used as

In the method of the present invention, the molar ratio of tetracarboxylic dianhydride and dicarboxylic anhydride is 1 molar ratio of diamine represented by formula (I) to 0 molar ratio of tetracarboxylic dianhydride represented by formula (II). The polyamic acid obtained in the presence of a dicarboxylic acid anhydride of 0.001 to 1.0 molar ratio, preferably 0.01 to 0.5 molar ratio is Alternatively, it can be obtained by chemical imidization, but the feature of the present invention lies in the dicarboxylic anhydride used here.The dicarboxylic anhydride directly or indirectly contributes to the reaction during the production of polyimide, and is It acts as a part of the components or as a catalyst in the polyimide production reaction, and plays a major role in obtaining polyimide with good processability. That is, dicarboxylic acid anhydride is 0.0
If the molar ratio is less than 0.01, it will not be possible to obtain a polyimide with good processability, and conversely, if the molar ratio is greater than 1.0, a polyimide with good mechanical properties will not be obtained.

Polyimide having good processability can be produced in the presence of dicarboxylic acid anhydride at a molar ratio of 0.001 to 1.0;
In this case, the ratio of tetracarboxylic dianhydride and diamine used as raw materials for polyimide is as follows: 1.0 molar ratio of diamine and 0.9 to 1.0 molar ratio of tetracarboxylic dianhydride are used. The polyimide of the present invention having good thermal stability at high temperatures cannot be obtained outside this range.

Polyimide is produced using the above tetracarboxylic dianhydride, diamine, and dicarboxylic anhydride, and in this case, all known methods for producing polyimide can be used.

That is, (I) a tetracarboxylic dianhydride, a diamine, and a dicarboxylic acid anhydride king are dissolved in an organic solvent (for example, N,N-dimethylacetamide, N,N-dimethylformamide, etc. used for ordinary polyimide). (2) Method of dissolving tetracarboxylic dianhydride and diamine in an organic solvent and then adding dicarboxylic anhydride to react (3) Dissolving diamine and dicarboxylic anhydride in an organic solvent Any addition or reaction method may be used, such as adding and reacting tetracarboxylic dianhydride after the addition of tetracarboxylic dianhydride.

The reaction temperature is O'C to 250'C, but usually 6
It is carried out at temperatures below 0°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 tetracarboxylic dianhydride and dicarboxylic anhydride used, the type of solvent, and the reaction temperature, but usually 4 to 24 hours is sufficient.

Through such a reaction, a polyamic acid having a repeating unit of the following formula (V) as a basic skeleton is produced.

(In the formula, R is the same as above) This polyamic acid is dehydrated by heating at 100 to 400°C, or chemically imidized using a commonly used imidizing agent, such as triethylamine and acetic anhydride, to form the following formula: A corresponding polyimide having the repeating unit (TV) as a basic skeleton is obtained.

(In the formula, R is the same as above.) Generally, after producing polyamic acid at a low temperature,
Further, this is thermally or chemically imidized. However, polyimide can also be obtained by simultaneously performing the production of polyamic acid and the thermal imidization reaction at a temperature of 60° C. to 250° C.

That is, diamine, tetracarboxylic dianhydride, and aromatic dicarboxylic anhydride are suspended or dissolved in an organic solvent and then reacted under heating to simultaneously produce polyamic acid and dehydrate and imidize it. A polyimide having the repeating unit of the above formula (IV) as a basic skeleton can also be obtained.

Another method is to mix tetracarboxylic dianhydride, diamine, and dicarboxylic anhydride in powder form without using a solvent, and then process the mixture in the presence or absence of a chemical imidizing agent to form polyimide. can also be used.

When the polyimide of the present invention is subjected to melt molding, other thermoplastic resins such as polyethylene, polypropylene, polycarbonate, polyarylate, polyamide, polysulfone, polyether sulfone, polyether ketone may be used as long as the purpose of the present invention is not impaired. , polyphenylene sulfide, polyamideimide, polyetherimide, modified polyphenylene oxide, etc., may be blended in appropriate amounts depending on the purpose. Furthermore, the following fillers used in ordinary resin compositions may be used to the extent that the purpose of the invention is not impaired. In other words, wear resistance improving materials such as graphite, carborundum, silica powder, molybdenum disulfide, and fluororesins, and reinforcing materials such as glass fiber, carbon fiber, boron fiber, silicon carbide fiber, carbon whisker, asbestos, metal fiber, and ceramic fiber. , flame retardant improvers such as antimony trioxide, magnesium carbonate, and calcium carbonate, electrical property improvers such as clay and mica, anti-tracking agents such as asbestos, silica, and graphite, barium sulfate, silica, calcium metasilicate, etc. Acid resistance improvers, thermal conductivity improvers such as iron powder, zinc powder, aluminum powder, copper powder, etc. Glass beads, glass bulbs, talc, diatomaceous earth, alumina, shirasu balloon, etc.
These include hydrated alumina, metal oxides, and colorants. [Examples] Hereinafter, the present invention will be specifically explained using Examples and Comparative Examples.

Example 1 592 g (I, 0 mol) of bisif[3-(4-aminophenoxy)henzoyl]phenyl)ether was added to a reactor equipped with a stirrer, a reflux condenser and a nitrogen inlet tube.
and 4700 g of N,N-dimethylacetamide, and 207 g of biromellitic anhydride was added at room temperature under a nitrogen atmosphere.
g (0.95 mol) was added in portions while paying attention to the rise in volume and temperature, and the mixture was stirred at room temperature for about 20 hours.

To this polyamic acid solution, 17.6 g (0,155 mol) of glutaric anhydride was added under a nitrogen atmosphere at room temperature, and the mixture was further stirred for 1 hour. Next, add 202 g (2
mol) of triethylamine and 306 g (3 mol) of acetic anhydride were added dropwise. Stir at room temperature for 20 hours, remove the reaction product into methanol, filter, disperse and wash in methanol, filter and dry at 180°C for 2 hours to give 742g.
polyimide powder was obtained.

This polyimide powder had a glass transition temperature of 227'C1 and a melting point of 385° (according to DSC, the same applies hereinafter).

Moreover, the logarithmic viscosity of this polyimide powder was 0.55 a/g. Here, the logarithmic viscosity is a value measured using a mixed solvent of parachlorophenol:phenol (weight ratio 90:10) at a concentration of 0.5 g/1 oo. Using the polyimide powder obtained in this example, the relationship between melt viscosity and pressure (shear rate) was measured using a Koka type flow tester (Shimadzu Corporation, CFT500, orifice diameter 0.1 cm, length 1 cm).

Figure 1 shows the relationship between melt viscosity and shear rate measured at various shear rates after being maintained at a temperature of 410°C for 5 minutes.

Comparative Example 1 730 g of polyimide powder was obtained in exactly the same manner as in Example 1, except that the reaction with glutaric anhydride was not performed.

The logarithmic viscosity of the obtained polyimide powder is 0.55 d1/g
Met.

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

Example 2 592 g of bis(4-(3-(4-aminophenoxy)benzoyl]phenyl)ether was placed in the same apparatus as in Example 1.
(I, 0 mol) and 4700 g of dimethylacetamide
and 15.4 g (0.1 mol) of 1,2-cyclohexanedicarboxylic anhydride under a nitrogen atmosphere at room temperature.
304.8g (0.95mmol) of 3.3', 44
-Benzophenone tetracarboxylic dianhydride was added while being careful not to increase the solution temperature, and the mixture was stirred at room temperature for about 20 hours.

Next, 202 g (2 moles) of triethylamine and 306 g (3 moles) of acetic anhydride were added dropwise to this solution. 2
After stirring for 0 hours, the reaction product was discharged into methanol, filtered, washed with methanol, and dried under reduced pressure at 180°C for 8 hours to obtain 832 g of pale yellow polyimide powder. The glass transition temperature of this polyimide powder is 198°C, and the logarithmic viscosity is 0.
It was 53a/g.

The molding stability of the polyimide obtained in this example was measured by changing the residence time in the cylinder of a flow tester. Temperature was 320'C1 Pressure was 100kg/c+fl 0
The results are shown in Figure 2. Even if the residence time in the cylinder becomes longer, the melt viscosity hardly changes, indicating good thermal stability.

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

The glass transition temperature of the polyimide powder was 198°C, and the logarithmic viscosity was 0.53 (IJ!/g).As in Example 2, the residence time in the flow tester cylinder was varied and the melt viscosity was measured. As the time increased, the 78 melt viscosity increased, and the thermal stability was inferior to that of the polyimide obtained in Example 2.

Example 3 Bis(4-(3-(4-aminophenyxy)benzoyl]phenyl)ether 592
g (I mol), bis(3,4-dicarboxyphenyl)
297.6 g (0°96 mol) of ether dianhydride, 8.96 g (0.08 mol) of citraconic anhydride and 5
100 g of m-cresol was charged, heated under a nitrogen atmosphere while stirring, and heated to 150"C.
After continuing stirring for 4 hours, the mixture was cooled, the reaction mixture was poured into methanol, and filtered to obtain polyimide powder.

This polyimide powder was washed with methanol and acetone and then dried under reduced pressure at 180'C for 8 hours to obtain 823 g of polyimide powder.

The stiff polyimide powder had a logarithmic viscosity of 0.57 a/g and a glass transition temperature of 189°C.

The same measurements as in Example 1 were carried out at a temperature of 300°C,
The results shown in FIG. 3 were obtained.

Comparative Example 3 Polyimide $5 with logarithmic viscosity o and 57 d1/g was prepared in the same manner as in Example 3 except that citraconic anhydride was not used.
I got 1.

The same measurements as in Example 1 were carried out at a temperature of 300'C, and the results shown in FIG. 3 were obtained.

[Brief explanation of the drawing]

FIG. 1 shows a test using a Koka type flow tester (
Shimadzu, CFT-500, orifice diameter 0.1c
It is a curve diagram of the results of measuring the relationship between melt viscosity and pressure (shear rate) at m, length lc+a), and was measured at various shear rates after being maintained at a temperature of 410°C for 5 minutes. Figure 2 is a curve diagram showing the comparison of the melt viscosity measured by changing the residence time in the cylinder of a flow tester in order to compare the molding stability of polyimide powder in Example 2 of the present invention and Comparative Example 2. Yes, the measurement temperature is 320°C,
The measured pressure is 100 kg/c-. Figure 3 is a curve showing the relationship between melt viscosity and shear rate, which shows the results of the same measurements as in Example 1 performed on the polyimide powders obtained in Example 3 and Comparative Example 3 at a temperature of 300°C. It is a diagram. Patent applicant Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] 1. A method for producing polyimide in which diamine and tetracarboxylic dianhydride are reacted and the resulting polyamic acid is thermally or chemically imidized, in which (a) the diamine is of the following formula: (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) It is a diamine represented by (B) Tetracarboxylic dianhydride is the following formula (II)▲There are mathematical formulas, chemical formulas, tables, etc.▼(II ) (wherein R is an aliphatic group having 2 or more carbon atoms, a cycloaliphatic group,
Represents a tetravalent group selected from the group consisting of a monocyclic aromatic group, a fused polycyclic aromatic group, and a non-fused polycyclic aromatic group in which aromatic groups are interconnected directly or through a bridge member. . ) is a tetracarboxylic dianhydride represented by (c)
Furthermore, the reaction is expressed by the following formula (III) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (III) (In the formula, Z is an aliphatic group with 1 to 10 carbon atoms and /
Or it represents a divalent group consisting of a cycloaliphatic group. ) in the presence of dicarboxylic acid anhydride represented by (d) the amount of tetracarboxylic dianhydride is 0.9 to 1.0 molar ratio per 1 mole of diamine, and The amount is in a molar ratio of 0.001 to 1.0 per mole of diamine. Production of polyimide with good moldability that has a repeating unit represented by the following formula (IV) ▲Mathematical formula, chemical formula, table, etc.▼(IV) (In the formula, R represents the same as above) as a basic skeleton Method.