JPH0425964B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a method for producing polyamideimide and/or polyimide by reacting a diisocyanate with a tricarboxylic anhydride and/or a tetracarboxylic dianhydride in the coexistence of an alkali metal salt of a polyhydric carboxylic acid. . Prior Art Polyamideimide or polyimide produced according to the present invention has excellent heat resistance, electrical insulation properties,
Due to its mechanical properties, it can be widely used in fibers, films, molded products, varnishes, adhesives, etc. Producing polyamide from diisocyanate and dicarboxylic acid, producing polyamic acid from tricarboxylic acid or tetracarboxylic acid and diisocyanate, and further producing imide bonds by intramolecular dehydration ring closure reaction using this polyamic acid as a precursor to produce polyamide. Much is already known about producing imides or polyimides. The present inventors have recently discovered a novel highly active catalyst for the above reaction (Japanese Patent Application Laid-open Nos. 151615 and 179223);
Diisocyanate and dicarboxylic anhydride containing a free carboxyl group (trimellitic anhydride)
Alternatively, there are many known methods for producing polyamideimide or polyimide by reacting with tetracarboxylic dianhydride (for example, Japanese Patent Publication No. 40-8910,
41-19302, 42-16080, 44-19274, etc.).
Furthermore, as one of the few examples of using a new catalyst to accelerate similar reactions,
-13070 and JP-A-53-92703 are known. The method for producing polyamideimide or polyimide by reacting the diisocyanate and tricarboxylic anhydride or tetracarboxylic dianhydride described above is a one-step reaction with CO ₂ gas removal, and the diamine compound and polycarboxylic anhydride are reacted in two steps ( Amic acid production →
Compared to the method of producing polyamide-imide or polyimide by reacting (dehydration ring closure → imidization),
It has advantages such as ease of reaction, no deterioration of the polymer due to inert gas as a by-product, and easy processing, and has great economic and industrial advantages. However, the low solubility of the produced polyamide-imide or polyimide in organic polar solvents is often a problem, especially in monomer combinations of wholly aromatic polyamide-imide or polyimide, which may force polymerization at low concentrations or with a low degree of polymerization. There were also problems such as only being able to produce polymers. For this reason, most of their uses are varnishes, and it has been difficult to produce high-molecular-weight polymers that can be easily processed into films, fibers, molded products, and the like. Means for Solving Problems The present inventors have been studying the problems in the production of isocyanate/acid anhydride polyamideimide or polyimide as described above, especially for increasing the molecular weight, and found that the present invention The inventors, etc.
The inventors discovered that the monoalkali metal dicarboxylic acid salts disclosed in Nos. 57-151615 and 179223 were extremely effective here as well, and after conducting further intensive studies, they completed the present invention. That is, the method of the present invention enables the production of high molecular weight polyamideimide or polyimide by coexisting an alkali metal salt of a polyvalent carboxylic acid represented by the general formula () in the reaction of a polyvalent carboxylic acid and a diisocyanate. It is something. R(COOH)m(COOM)n () Here, R, M, m, and n each have the following meanings. R: is absent or is a divalent to tetravalent group, and may be substituted with a group or atom that does not react with carboxyl groups, acid anhydride groups, and isocyanates, or that does not react with them very easily. In the case of trivalence, two of the three carboxyl groups bonded to R are bonded to positions that form an acid anhydride, and in the case of tetravalence, two of the three carboxyl groups bonded to R are bonded to positions that form an acid anhydride. The four carboxyl groups present are bonded to positions that form two sets of acid anhydrides. M; alkali metal m; 0, an integer of 1 to 3 n; an integer of 1 to 4; However, m+n is an integer of 2 to 4. The above R is an aliphatic, aromatic, alicyclic, or heterocyclic group, and two or more of these groups are directly connected, for example, by carbon-carbon,
Or alkylene, -O-, -S-,

【formula】 【formula】 【formula】

【formula】

【formula】

【formula】 or

[Formula] etc. (wherein R' is an alkyl group, a cycloalkyl group or an aryl group, and when two are bonded, they may be different). Further, examples of groups or atoms that do not react or are very difficult to react with the carboxyl group, acid anhydride, and isocyanate include alkyl groups, cycloalkyl groups, aryl groups, alkoxy groups, and halogen atoms. Examples of compounds used in the method of the present invention are shown below, but the invention is of course not limited to these examples. Examples of the diisocyanate used in the present invention include 1,2-diisocyanate ethane, 1,2
-Diisocyanate propane, tetramethylene-
1,4-diisocyanate, pentamethylene-
1,5-diisocyanate, hexamethylene-
1,6-diisocyanate, nonamethylene-1,
9-diisocyanate, decamethylene-1,10-
Diisocyanate, aliphatic diisocyanate such as ω,ω′-dipropyl ether diisocyanate, cyclohexane-1,4-diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, hexahydrodiphenyl-4,4′-diisocyanate, hexahydrodiphenyl Alicyclic diisocyanates such as enyl ether-4,4'-diisocyanate, phenylene-1,3-diisocyanate, phenylene-1,4-diisocyanate, toluylene-2,6-diisocyanate, toluylene-2,4-diisocyanate, 1-methoxy Benzene-2,4-diisocyanate, 1-
Chlorophenyl diisocyanate, tetrachlorophenylene diisocyanate, metaxylylene diisocyanate, paraxylylene diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenyl sulfide-4,4'-diisocyanate, diphenyl sulfone-4,4 '-diisocyanate, diphenyl ether-4,4'-diisocyanate, diphenyl ether-3,4'-diisocyanate, diphenyl ketone-4,4'-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-1,4-diisocyanate , naphthalene-1,5-diisocyanate,
2,4'-biphenyl diisocyanate, 4,4'-
Aromatic aromas such as biphenyl diisocyanate, 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, anthraquinone-2,6-diisocyanate, triphenylmethane-4,4'-diisocyanate, azobenzene-4,4'-diisocyanate, etc. In particular, hexamethylene-1,6-diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, phenylene-1,3-diisocyanate, phenylene-1,3-diisocyanate,
1,4-diisocyanate, toluylene-2,4
-diisocyanate, toluylene-2,6-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenyl ether-4,4'-diisocyanate or mixtures thereof. Examples of polycarboxylic anhydrides used in the present invention include trimellitic anhydride, benzene-1,2,3-tricarboxylic anhydride, and naphthalene-2,3,6-tricarboxylic anhydride. , naphthalene-2,3,5-tricarboxylic anhydride, naphthalene-1,2,4-tricarboxylic anhydride, naphthalene-1,4,5-tricarboxylic anhydride, (2,3-dicarboxyphenyl) -(2-carboxyphenyl)methane anhydride, (2,3-dicarboxyphenyl)-(3-carboxyphenyl)methane anhydride, (3,4-dicarboxyphenyl)-(3-carboxyphenyl) enyl)methane anhydride, (3,4-dicarboxyphenyl)-(4-carboxyphenyl)methane anhydride, 1-(3,4-dicarboxyphenyl)-1-
(3-carboxyphenyl)ethane anhydride, 1-
(3,4-dicarboxyphenyl)-1-(4-carboxyphenyl)ethane anhydride, 2-(3,4
-dicarboxyphenyl)-2-(3-carboxyphenyl)propane anhydride, 2-(3,4-dicarboxyphenyl)-2-(3-carboxyphenyl)propane anhydride, 3,3' , 4-tricarboxybenzophenone anhydride, 2,2',3-tricarboxybiphenyl anhydride, etc. In particular, trimellitic anhydride, naphthalene-2,3,6-tricarboxylic anhydride, etc. A mixture of is preferred. Examples of tetracarboxylic dianhydride include pyromellitic dianhydride, 2,3,6,7-
naphthalenetetracarboxylic dianhydride, 1,4,
5,8-naphthalenetetracarboxylic dianhydride,
Bis(3,4-dicarboxyphenyl)methane 2
Anhydride, bis(3,4-dicarboxyphenyl)
Propane 2 anhydride, bis(3,4-dicarboxyphenyl) ether 2 anhydride, bis(3,4-dicarboxyphenyl) sulfone 2 anhydride, bis(3,4-dicarboxyphenyl) ketone 2 Anhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, 3,3',4,4'-biph Examples include enyltetracarboxylic dianhydride, particularly pyromellitic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,
4′-benzophenonetetracarboxylic dianhydride,
1,2,3,4-butanetetracarboxylic dianhydride or mixtures thereof are preferred. Furthermore, even if a part (about 10 mol % or less) of the anhydride groups in the molecule of the above-mentioned polyvalent carboxylic acid anhydride are hydrolyzed and coexist as a polyvalent carboxylic acid, this does not affect the actual state of the reaction. In this case, a small amount of amic acid units will be contained in the polymer main chain. Furthermore, molecular design by copolymerization with dicarboxylic acids, various tricarboxylic acids, tetracarboxylic acids, etc. is also possible. Furthermore, the alkali metal salts of polyvalent carboxylic acids used in the present invention include mono- and/or di- and/or tri- and/or tetralithium salts of dicarboxylic acids, tricarboxylic acids, and tetracarboxylic acids represented by the above general formula (); Examples include sodium salts, potassium salts, rubidium salts, cesium salts, and francium salts, especially oxalic acid, adipic acid, azelaic acid, sebacic acid, terephthalic acid, isophthalic acid,
Mono- and/or disodium or potassium salts of diphenyl ether-4,4'-dicarboxylic acid, pyridine-2,6-dicarboxylic acid or cyclohexane-1,4-dicarboxylic acid, or pentane-
1,2,5-tricarboxylic acid, cyclohexane-
1,2,3-tricarboxylic acid, benzene-1,
2,4-tricarboxylic acid, naphthalene-1,4,
5-tricarboxylic acid, naphthalene-2,3,6-
Tricarboxylic acid, mono- and/or di- and/or tri-sodium salt or potassium salt of 3,4,4'-benzophenone tricarboxylic acid, or butane-1,2,3,4-tetracarboxylic acid, benzene-1 , 2,4,5-tetracarboxylic acid, 3,3',
4,4'-Benzophenonetetracarboxylic acid, 3,
3',4,4'-biphenyltetracarboxylic acid, 3,
Mono- and/or di- and/or tri- and/or tetra-sodium or potassium salts of 3',4,4'-diphenyl ether tetracarboxylic acid and 3,3',4,4'-diphenyl sulfone tetracarboxylic acid etc. or a mixture of two or more of these are preferred. Furthermore, these alkali metal salts of polyhydric carboxylic acids may be used as adduct compounds with organic polar solvents, such as N-methyl-2-pyrrolidone. Effect When the alkali metal salt of the polyhydric carboxylic acid is used in the reaction between the polycarboxylic acid and the anhydride diisocyanate of the present invention, it is preferable to use one that is industrially and economically advantageous. However, particularly favorable effects can be obtained by using an alkali metal salt of a polycarboxylic acid having a structure similar to the polycarboxylic acid anhydride used as a raw material for polymerization. The reaction of a polycarboxylic acid anhydride and a diisocyanate according to the method of the present invention is carried out in the presence of the alkali metal salt of a polycarboxylic acid, generally in an anhydrous organic polar solvent, and under a stream of an inert gas, for example, nitrogen. Alternatively, it may be carried out by heating at a temperature of about 20 to 250°C, preferably 50 to 200°C, for about 1 to 20 hours while removing by-product CO ₂ gas under reduced pressure. Examples of organic polar solvents include linear or cyclic amides such as N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone, α-butyrolactone, or hexamethylphosphoric triamide. or phosphorylamides, or sulfones such as tetramethylene sulfone and diphenyl sulfone are used. These organic polar solvents can also be used after being diluted with other neutral solvents such as benzene, toluene, xylene, cresol, cyclohexane, pentane, hexane, heptane, methylene chloride, tetrahydrofuran, cyclohexanone, and dioxane. Further, for example, metal salts such as lithium chloride and calcium chloride may be contained. In addition, the method, order, and timing of addition of the raw material monomer and the alkali metal salt of polycarboxylic acid can be arbitrarily selected, and in any case, the amide bonding reaction is greatly accelerated, but preferably these are carried out at room temperature. The two or more solutions may be dissolved simultaneously or sequentially in a solvent, or may be dissolved separately and the two or more solutions may then be mixed or, in some cases, may be mixed in the solid state with a solution. In some cases, it is also possible to add either one of the raw material monomers continuously under the reaction temperature, or to add the polycarboxylic anhydride, diisocyanate, and alkali polycarboxylic acid in a solvent-free state. By mixing and heating metal salts, it is possible to produce high molecular weight foams in an extremely short period of time. Generally, the concentration of raw material monomers (polycarboxylic anhydride + diisocyanate) at the start of the polymerization reaction is selected in the range of 50 to 400 g/solvent.
This concentration is selected depending on the reactivity of the raw material monomers, the solubility of the polymer in the polymerization solvent, etc. When polymerization is started at a high concentration, it is preferable to add the solvent continuously or discontinuously, as the case may be, so as not to interfere with stirring due to thickening during the polymerization. The molar ratio of the diisocyanate to the polyhydric carboxylic acid anhydride is preferably substantially equivalent in the range of 0.7 to 1.30, particularly preferably in the range of 0.95 to 1.10. The amount of the alkali metal salt of polyvalent carboxylic acid added is preferably 0.1 to 20 mol%, particularly preferably 0.5 to 10 mol%, based on the polyvalent carboxylic acid anhydride. When a polyvalent carboxylic acid anhydride and a diisocyanate are reacted in a substantially anhydrous state in the presence of an alkali metal salt of a polyvalent carboxylic acid in, for example, an organic polar solvent according to the method of the present invention, the alkali metal salt does not coexist. There is a marked increase in the reaction rate and degree of polymerization compared to the conventional case. The polyamide-imide or dope prepared by redissolving the polymerized solution of polyimide or the separated polymer obtained by the method of the present invention has good stability, and when used as a varnish, adhesive, etc., the solvent must be carefully removed by volatilization. If applied, it is easy to form a high-quality enamel or adhesive layer with extremely few voids, and since it is a high molecular weight polymer, multiple coats can be saved.
In addition, when forming a cast film, a high-quality film can be produced using a more streamlined process than the conventional method using polyamic acid dope as a raw material. Examples The method of the present invention will be illustrated by examples below.
The present invention is not limited to these. Example 1 In a 500 ml separable flask equipped with a stirrer, a thermometer, and a nitrogen inlet tube, 15.04 g (0.0783 mol) of trimellitic acid anhydride, 0.1810 g (0.0008 mol) of trimellitic acid monosodium salt, and purification were added under a nitrogen atmosphere. 300 ml of N-methylpyrrolidone (hereinafter abbreviated as NMP) was added, heated at 80°C for 30 minutes to form a homogeneous solution, and then cooled to 50°C. Diphenylmethane-4,4'-diisocyanate-
9.970 g (0.0398 mol) and an 80/20 molar ratio mixture of 2,4-toluylene diisocyanate/2,6-toluylene diisocyanate (hereinafter TDI-80/20
5.983 g (0.0401 mol) was added, and the mixture was heated to 120° C. within about 20 minutes, and then reacted for 4 hours. As the reaction progressed, carbon dioxide gas was actively generated, and the solution turned from yellow to reddish-orange, and its viscosity gradually increased. Approximately 2 hours after the start of the reaction, the generation of carbon dioxide gas is almost no longer observed;
After continuing the reaction for an hour, it was cooled to room temperature. A portion of this polymerization solution was cast onto a glass plate to a thickness of 0.4 m/m and dried in a hot air dryer at 80°C for about 3 hours, resulting in a self-supporting film that could be peeled off from the glass plate. This was cut into 10cm squares, fixed with clips on all sides, and then placed in a vacuum dryer at 250°C.
The film obtained by main drying for 1 hr → 300℃/1hr → 350℃/1hr is brown and strong, and has a high tensile strength.
The weight was 1270Kg/cm ² and the elongation was 12%. Separately, a portion of the polymerization solution was poured into about 10 times the volume of methanol to precipitate the polymer, and after washing thoroughly with methanol, the mixture was heated at 100°C for 5 hours for 2 to 3 hours.
Drying under reduced pressure of mmHg gave an ocher powder. The intrinsic viscosity of this polymer (0.5% in NMP, 30°C, same hereafter) was 1.14. Furthermore, the infrared absorption spectrum of an ultrathin film made from a dilute NMP solution of this polymer in the same manner as above is 1780 cm ^-1 , 1720 cm -1
There are absorption bands of imide group at cm ^-1 , 1370cm ^-1 and 725cm ^-1 ,
Also, absorption of amide group was observed at 1660 cm ^-1 . Comparative Example 1 15.11 g (0.0786 mol) of trimellitic anhydride, 6.983 g (0.0401 mol) of TDI-80/20, and 6.983 g (0.0401 mol) of TDI-80/20 were prepared using the same apparatus and method as in Example 1, except that trimellitic acid monosodium salt was not present. , diphenylmethane-4,4'-diisocyanate 10.07
A mixture of 140 g (0.0402 mol) and 300 ml of NMP
The reaction was carried out at ℃ for 4 hours. After the reaction started, the solution turned reddish brown as carbon dioxide gas was generated, but the viscosity of the solution only increased slightly. An attempt was made to produce a cast film from the polymerization solution in the same manner as in Example 1, but the film broke into several pieces during the main drying and a satisfactory film could not be obtained. The intrinsic viscosity of the polymer obtained by post-treatment in the same manner as in Example 1 was 0.40. Example 2 Pyromellitic acid dianhydride, 15.12 g (0.0693 mol), pyromellitic acid disodium salt 0.2070 g (0.0007 mol), and diphenylmethane-4,4'-diisocyanate, 8.834 g (0.0007 mol) were prepared using the same apparatus and method as in Example 1. g (0.0353 mol), TDI-80/20, 6.165
(0.0354 mol) and 300 ml of purified NMP.
The mixture was reacted at 120°C for 4 hours to obtain a reddish brown high viscosity liquid.
The intrinsic viscosity of the ocher polyimide powder obtained by treating this in the same manner as in Example 1 was 0.81, and the tensile strength of the cast film was 1340 Kg/cm ² and the elongation was 8.7%.
It was hot. Comparative Example 2 Pyromellitic acid 2 was prepared in the same manner as in Example 2 except that pyromellitic acid disodium salt was not present
A mixture of 15.11 g (0.0693 mol) of anhydride, 8.860 g (0.0354 mol) of diphenylmethane-4,4'-diisocyanate, 300 ml of purified NMP was reacted at 120°C for 4 hours to form a reddish brown color. A solution was obtained. The intrinsic viscosity of the polymer obtained by the same treatment as in Example 1 was 0.31. Example 3 A 100 ml dropping funnel was attached to the same apparatus as in Example 1, and 15.08 g (0.0468 mol) of 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',
A mixture of 0.2169 g (0.0005 mol) of diurium 4,4'-benzophenonetetracarboxylic acid salt and 250 ml of NMP was heated to 160°C, and to this was added 6.003 g (0.0238 mol) of diphenyl ether-4,4'-diisocyanate and TDI- 80/204.157g (0.0239mol) in 50ml
A solution dissolved in NMP was added dropwise over 4 hours. As the reaction progressed, the solution turned from brown to reddish-orange and its viscosity gradually increased. At the end of the isocyanate addition, there was a significant increase in viscosity. 1 more
After continuing the reaction for an hour, the mixture was diluted with 100 ml of NMP, cooled, and post-treated in the same manner as in Example 1 to obtain a dark yellow polymer. The intrinsic viscosity of this polymer was 0.88, and the cast film was strong, exhibiting a tensile strength of 1290 Kg/cm ² and an elongation of 9.5%. Example 4 The same reaction as in Example 3 was carried out using isophthalic acid monosodium salt in place of the 3,3',4,4'-benzophenonetetracarboxylic acid dipotassium salt of Example 3. The intrinsic viscosity of purified polyimide is
It was 0.92. Comparative Example 3 3,3',4,4'-benzophenonetetracarboxylic acid dipotassium salt in Example 3 and Example 4
3,3',4,
4'-Benzophenonetetracarboxylic dianhydride
15.15 g (0.0470 mol) of diphenyl ether-4,4'-diisocyanate in a solution of 250 ml of NMP.
6.040g (0.0239mol) and TDI-80/204.174g
(0.0240 mol) dissolved in 50 ml of NMP to 160 mol.
The dropwise reaction was carried out at ℃ over 4 hours. The solution turned red-orange, but the solution viscosity only increased slightly. The obtained polymer, which was treated in the same manner as in Example 3, had an intrinsic viscosity of 0.35. Furthermore, the cast film produced in the same manner as in Example 1 was brittle and could not withstand bending. Effects of the Invention The present invention produces a high molecular weight polyamide-imide or polyimide that can be processed into films etc. by allowing an alkali metal salt of a polyvalent carboxylic acid to coexist during the reaction between a diisocyanate and a polyvalent carboxylic acid anhydride. can do.

Claims (1)

[Scope of Claims] 1. A method for producing polyamideimide or polyimide, which comprises coexisting an alkali metal salt of a polyvalent carboxylic acid represented by the general formula () in the reaction between a diisocyanate and a polyvalent carboxylic acid anhydride. R(COOH)m(COOM)n () However, R, M, m, and n in the above formula each mean the following. R: does not exist or is a divalent to tetravalent group, and may be substituted with a group or atom that does not react or does not react with carboxyl groups, acid anhydride groups, and isocyanates. In the case of trivalence, two of the three carboxyl groups bonded to R are bonded to positions that form an acid anhydride, and in the case of tetravalence, R
The four carboxyl groups bonded to are bonded to positions that form two sets of acid anhydrides. M: Alkali metal. m: 0, an integer from 1 to 3. n: an integer of 1 to 4. However, m+n is an integer of 2 to 4. 2. The method according to claim 1, wherein the polycarboxylic anhydride is a tricarboxylic anhydride. 3 Polyhydric carboxylic acid anhydride is tetracarboxylic acid 2
The method according to claim 1, which is an anhydride. 4. The method according to claim 1, wherein the polycarboxylic anhydride comprises tricarboxylic anhydride and tetracarboxylic dianhydride. 5. The method according to any one of claims 1 to 4, wherein the alkali metal of the polyhydric carboxylic acid alkali metal salt is sodium or potassium. 6. The method according to any one of claims 1 to 5, wherein the polycarboxylic acid alkali metal salt is a mono- and/or dialkali metal dicarboxylic acid. 7. The method according to any one of claims 1 to 5, wherein the alkali metal salt of polycarboxylic acid is a mono- and/or di- and/or trial-alkali metal salt of tricarboxylic acid. 8 Polyhydric carboxylic acid alkali metal salt is tetracarboxylic acid mono- and/or di- and/or tri- and/
or a tetraalkali metal salt, the method according to any one of claims 1 to 5.