JPS6114218A - Production of polyamide-imide or polyimide - Google Patents

Abstract

PURPOSE:To facilitate the formation of a high-MW polyamide-imide or polyimide which can be readily molded into fibers, etc., by reacting a diisocyanate with a polycarboxylic acid anhydride in the presence of a specified alkali metal polycarboxylate. CONSTITUTION:An alkali metal polycarboxylate of the formula (wherein R is a single bond or a bi- - tetra-valent group which may have groups or atoms unreactive or difficultly reactive with a carboxyl group, anhydride group or isocyanato group, M is an alkali metal, m is 0, or 1-3, n is 1-4, and m+n=2-4), e.g., monosodium trimellitate, is used to prepare a polyamide-imide or polyimide by reacting a diisocyanate (e.g., toluylene 2,4-diisocyanate) with a polycarboxylic acid anhydride (e.g., trimellitic anhydride).

Description

DETAILED DESCRIPTION OF THE INVENTION - Item '1' above The present invention produces polyamide-imide and /Or relates to a method for producing polyimide.

4. The polyamide-imide or polyimide produced by the present invention can be widely used in fibers, films, molded products, varnishes, adhesives, etc. by taking advantage of its excellent heat resistance, electrical insulation, mechanical properties, etc. I can do it.

Producing polyamide from diisocyanate and dicarboxylic acid, or 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-imide or Much is already known about producing polyimides. The present inventors have recently discovered a novel highly active catalyst for the above reaction (Japanese Patent Application Laid-open Nos. 151815 and 179223).
,on the other hand.

Many methods are also known for producing polyamideimide or polyimide by reacting diisocyanate with dicarboxylic anhydride (trimellitic anhydride) or tetracarboxylic dianhydride having a free carboxyl group (for example,
Special public Sho 4G-H2O No. 41-19302, No. 42
= 18080, No. 44-18274, etc.), and in a similar reaction, new 4 Yani, 9
□Oh, 4, 7, 5. 87 '47-13070
No. 53-82703 is known.

The method of producing polyamideimide or polyimide by reacting the above diisocyanate with tricarboxylic acid anhydride or tetracarboxylic acid 2m hydrate is a one-step reaction of removing CO2 gas, and the diamine compound and polycarboxylic acid anhydride are reacted with
Compared to the method of producing polyamide-imide or polyimide by reacting in steps (amic acid generation → dehydration ring closure → imidization), the reaction is easier, the by-product is an inert gas and does not cause deterioration of the polymer, and processing is easier. It has the advantages of number 1 and has great economic and industrial advantages, but the low solubility of the produced polyamide-imide or polyimide in organic polar solvents is often a problem, especially in the monomer combination of wholly aromatic polyamide-imide or polyimide. Therefore, there were problems such as being forced to polymerize at a low concentration and only being able to produce polymers with a low degree of polymerization. For this reason, most of these materials are used as 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.

The inventors of the present invention have been studying the above-mentioned problems in the production of isocyanate/acid anhydride-based polyamide-imide or polyimide, especially for increasing the molecular weight. JP-A No. 57-151815, No. 1
It was discovered that the dicarbonate mono-alkali metal salt disclosed in No. 79223 was extremely effective here as well, and after further intensive study, the present invention was completed.

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 (I) in the reaction of a polyvalent carboxylic acid and a diisocyanate. It is.

R(COOH)m(COjlN)n(I)
Here, R, M, m, and n each mean the following.

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. There are 4
The carboxyl groups are bonded at positions forming two sets of acid anhydrides.

M: alkali metal m; integer from 0.1 to 3 n: integer from 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, for example, directly connected with carbon-carbon, or alkylene, -O-,
-S-, -S-.

(Here, Ro 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.

As the diisocyanate used in the present invention, for example, 1
．． 2-diisocyanate ethane, 1,2-diisocyanate propane, tetramethylene-1,4-diisocyanate, pentamethylene-1,5-diisocyanate, hexamethylene-1,6-diisocyanate, nonamethylene-1,8-diisocyanate, decamethylene-1 ,l
O-diisocyanate, aliphatic diisocyanates such as ω, ω°-dipropyl ether diisocyanate, cyclohexane-1,4-diisocyanate, dicyclohexylmethane-4,4°-diisocyanate, hexahytho-diisocyanate, etc.
Difluoro-4,4-diiso-cyanate, alicyclic diisocyanates such as hexahydrodiphenyl ether-4,4'-diisocyanate, and phenylene-1,3-diisocyanate, phenylene-1,4-diisocyanate, toluylene-2,6- Diisocyanate, toluylene-2,4-diisocyanate, l-meth-t-sibenzene-2,4-diisocyanate, 1-chlorophenylene diisocyanate, tetrachlorophenylene diisocyanate, metaxylylene diisocyanate, paraxylylene diisocyanate, diphecol methane-4.4 '-diisocyanate, diphenyl sulfide = 4.4-diisocyanate, diphenyl sulfone-
4,4'-diisocyanate, diphenyl ether-4
, 4°-diisocyanate, diphenyl ether-3,
4'-diisocyanate, diphecorgaton-4.4'
-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, 2,4'-biphenyl diisocyanate, 4,4°-biphenyl diisocyanate, 3,3°-dimethoxy- Aromatic diisocyanates such as 4,4''-biphenyl diisocyanate, anthraquinone-2,6-diisocyanate, triphenylmethane-4,4''-diisocyanate, azobenzene-4,4''-diisocyanate, and especially hexamethylene-1, 6-diisocyanate, dicyclohexylmethane-4,4-diisocyanate, phenylene-1,
3-diisocyanate, phenylene-1,4-diisocyanate, toluylene-2,4-diisocyanate, toluylene-2,6-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenyl ether-4,4-diincyanate-1, or these. A mixture of is preferred.

Among the polycarboxylic acid anhydrides used in the present invention, examples of the tricarboxylic anhydride include trimellitic anhydride, benzene-1,2,3-)licarboxylic acid anhydride, and naphthalene-2,3,8-tricarboxylic acid. Anhydride, naphthalene-2
,3,5-)licarponic acid anhydride, naphthalene-1,2
,4-)licarponic acid anhydride, naphthalene=l,a,5
- Tricarboxylic anhydride, (2,3-dicarboxyphecol)-(2-carboxyphenyl)methane anhydride, (2,3-dicarboxyphenyl)-(3-carpoxyphenyl)methane anhydride, ( 3,4-dicarboxyphenyl)-(3-carboxyphenyl)methane anhydride,
(3,4-dicarboxyphenyl)-(4-carboxyphenyl)methane anhydride, 1-(3,4-dicarboxyphenyl)-1-(3-rupoxyphenyl)ethane anhydride, 1-(3-dicarboxyphenyl)-1-(3-carboxyphenyl)ethane anhydride ,4-dicarboxyphenyl)-1-(
4-carboxyphenyl)ethane anhydride, 2-(3,4
-dicarboxyphenyl)-2-(3-carboxyphenyl)propane anhydride, 2-(3,4-dicarboxyphenyl)-2-(3-carboxyphenyl)pronokne anhydride, 3,3°4- Examples include tricarboxybenzophenone anhydride, 2,2°,3-tricarboxybiphenyl anhydride, etc., and trimellitic anhydride, naphthalene-2,3,6-tricarboxylic anhydride, etc., or mixtures thereof are particularly preferred. .

Examples of tetracarboxylic dianhydrides include 1, pyromellitic dianhydride, 2, 3. L? -Naphthalenetetracarboxylic dianhydride, 1,4,5.8-naphthalenetetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)methane? Water collection, bis(3,4-dicarboxyphenyl)propane dianhydride, bis(3,dicarboxyphenyl)ether 2f#, water, bis('3.4
-dicarboxyphenyl)sulfone 2 anhydride, bis(3
,4-dicarboxyphenyl)ketone dianhydride,3,3
゛, 4,4゛-Hensephenonetetracarboxylic acid 21!
A hydrate, L, 2,3.4-butanetetracarboxylic acid dianhydride, 3.3',4,4°-biphenyltetracarboxylic acid 2f#, hydrate, etc., especially pyromelli nitrate dianhydride. Anhydride, 2,3,8.7-naphthalenetetracarboxylic dianhydride, 3.3',4,4°-benzophenonetetracarboxylic dianhydride, 1,2,3.4-butanetetracarboxylic acid ? Anhydrides or mixtures thereof are preferred.

Furthermore, even if a part (approximately 10 mol% or less) of the anhydride group in the molecule of the above-mentioned polyvalent carboxylic acid anhydride is hydrolyzed and coexists as a polyvalent carboxylic acid, the actual state of the reaction will not be affected. 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.

In addition, as the alkali metal salt of a polycarboxylic acid used in the present invention, mono and/or di and/or tri and/or tetra lithium of dicarboxylic acid, tricarboxylic acid, and tetracarboxylic acid shown in the above general formula (I) are used. Salts, sodium salts, potassium salts, rubidium salts, cesium salts and francium salts, etc., especially oxalic acid, adipic acid, azelaic acid, cepacic acid, terephthalic acid, isophthalic acid, diphenyl ether-4,4°-dicarboxylic acid, pyridine -2,6-dicarboxylic acid or cyclohexane-1,4-
Mono and/or disodium salts or potassium salts of dicarboxylic acids, or pentane-1,2,5-)dicarboxylic acid, cyclohexane-1,2',3-)dicarboxylic acid, benzene-1,2,4-1licarboxylic acid acid, naphthalene-1,4,5-) dicarboxylic acid, naphthalene-2,3,
8-tricarboxylic acid, mono- and/or di- and/or tri-sodium salt or potassium salt of 3,4,4°-benzophenonetricarboxylic 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, 3,3°,4,4'-diphenyl ethertetracarboxylic acid and Mono- and/or di- and/or tri- and/or tetra-sodium salts or potassium salts of 3,3',4,4°-diphenylsulfone tetracarboxylic acid, or mixtures of two or more thereof 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.

When an alkali metal salt of the polycarboxylic acid is used in the reaction of the polycarboxylic acid and anhydride diisocyanate of the present invention, it is preferable to use the kind that is industrially and economically advantageous. Preferably though.

Particularly favorable effects can be obtained by using an alkali metal salt of a polycarboxylic acid having a structure similar to that of the polycarboxylic acid anhydride used as a raw material for polymerization.

The reaction of a polycarboxylic 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. Or C produced as a by-product under reduced pressure
This is 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 O2 gas.

Examples of organic polar solvents include button-like or cyclic amino acids such as N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone, α-butyrolactone, or hexamethylphosphoric triamide. F or phosphorylamides, or sulfones such as tetramethylene sulfone and diphenyl sulfone are used. These organic polar solvents can also be used after being cooled 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 addition, depending on the case, it is possible to continuously add either one of the raw materials or additives under the reaction temperature, and furthermore, it is possible to add polycarboxylic acid anhydride, diisocyanate, and polycarboxylic acid alkali 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.

In general, the concentration of additives (polycarboxylic anhydride + diisocyanate) in the raw materials at the start of the polymerization reaction is 50 to 40.
0g/j! A range of solvents is selected, and the 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.

Further, the molar ratio of diisocyanate to polyhydric carboxylic acid anhydride is preferably substantially equivalent in the range of 0.7 to 1.30, particularly preferably in the range of 0.35 to 1.10.

The amount of the alkali metal salt of polycarboxylic acid added is preferably 0.1 to 20 mol%, particularly preferably 0.5 to 10 mol%, based on the polycarboxylic 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.

Furthermore, 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 below by way of one practical example, but the present invention is not limited by these.

Example 1 In a 5001 Separasol flask equipped with a stirrer, a thermometer, and a nitrogen inlet tube, 15.04 g (0,0783 mol) of trimellitic acid anhydride and 0.1810 g of trilift acid monosodium salt were added under a nitrogen atmosphere. (0,0008 mol)
and purified N-methylpyrrolidone (hereinafter abbreviated as NIP),
300@l was added, heated at 80°C for 30 minutes to form a homogeneous solution, and then cooled to 50°C. To this was added 9.970° (0,0398 mol) of diphenylmethane-4,4°-diisocyanate and 2. ．． 4-Toluylene diisocyanate) / 2.6-Toluylene diisocyanate 80/20 molar ratio mixture (hereinafter abbreviated as TDI-80/20) 5.983 g (0,0401 mol) was added,
The mixture was heated to 120'C within about 20 minutes,
Thereafter, as the reaction proceeded for 4 hours, carbon dioxide gas was actively generated, and the color of the solution changed from yellow to reddish orange, and its viscosity gradually increased. Approximately 2 hours after the start of the reaction, almost no carbon dioxide gas was generated, but the reaction was continued for an additional 2 hours and then cooled to room temperature.

A part 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, suspended, and placed in a vacuum dryer at 250°C/lhr → 300°C/l.
hr → The film obtained by main drying at 350°C/lhr is brown and strong, with a tensile strength of 1270 kg/c.
rn' and 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 thoroughly washing with Metamer, it was dried at 100°C for 5 hours under a reduced pressure of 2 to 3 mmHg. An ocher powder was obtained. The intrinsic viscosity of this polymer (0.5% in NMP, 30°C, same hereafter) is 1.1
It was 4. 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 1780cm-'+1720c+++-'',
Imide group absorption bands were observed at j370cm, -' and 725ca+-', and amide group absorption was observed at IEt80cm-'.

Comparative Example 1 15.11 g (0,0788 mol) of trimellitic anhydride, D
I-80/20. [1,1183 g (0,0401 mol), 10.07 g (0,0402 mol) diphenylmethane-4,4°-diisocyanate and NMP 300
The mixture of d was reacted at 140°C 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 01 polymerization solution in the same manner as in Example 1, but the film broke into several pieces during 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 Using the same apparatus and method as in Example 1, 15.12 g (0,0893 mol) of pyronolitic dianhydride and 0.20 g (0,0893 mol) of pyromellitic acid disodium salt were prepared. Og(0,000
7 mol) diphenylmethane-4,4°-diisocyanate, 8.834 g (0,0353 mol), T
DI-80/20. A mixture of 8.165 g (0,0354 mol) and purified NMP 300d was reacted at 120°C for 4 hours to obtain a reddish brown high viscosity liquid. Example 1
The intrinsic viscosity of the ocher-colored polyimide powder obtained by the same treatment as above was 0.81, and the tensile strength of the cast film was 1340 kg/cm' and the elongation was 8.7%.Comparative Example 2 15. Pyromellitic dianhydride was prepared in the same manner as in Example 2 except that no sodium salt was allowed to coexist. t
tg (o, oe+s3 mol), diphenylmethane-4,
4°-diisocyanate, 8.880 g (0,0354
mole), TDI-80/208.153g (0,
A mixture of 0353 mol) and 300 ml of purified NMP was reacted at 120° C. for 4 hours to obtain a reddish brown solution.

The intrinsic viscosity of the polymer obtained by the same treatment as in Example 1 was 0.
．． It was 31.

Example 3 A device similar to Example 1 was equipped with a 100 tffi dropping funnel, and 15.08 g (0,0468 mol) of 3.3',4,4-benzophenonetetracarponic dianhydride was added.
3.3',4.4-Benzphenonetetracarboxylic acid dipotassium salt 0.2169 g (0,0005 mol), N
A mixture of MP 250@1 was heated to 160°C, and diphenyl ether-4,4'-diisocyanate θ,
OC13g (0,0238 mol), T[1I-80
A solution of 204.157 g (0.0239 mol) dissolved in 501 NMP was added dropwise over 4 hours. As the reaction progressed, the solution changed from brown to reddish orange and its viscosity gradually increased. There was a significant increase in viscosity at the end of the isocyanate addition. After continuing the reaction for another hour, 100 m
The mixture was diluted with 1 liter of NMP, cooled, and worked up in the same manner as in Example 1 to obtain a deep yellow polymer. The intrinsic viscosity of this polymer was 0.88, and the cast film was tough, exhibiting a tensile strength of 1290 kg/crn' and an elongation of 8.5%.

Example 4 The same reaction as in Example 3 was carried out using isophthalic acid dipotassium salt in place of the 3.3', 4,4'-benzophenonetetracarboxylic acid dipotassium salt in Example 3. The purified polyimide had an intrinsic viscosity of 0.92.

Comparative Example 3 3,3°, 4,4°-benzophenonetetracarboxylic acid dipotassium salt in Example 3 and inphthalic acid monosodium salt in Example 4 were not used in the same manner as in Example 3. 4.4'-Henzophenone tetracarboxylic acid dianhydride 15.15g, (0,0470
mol), 6.040 g of diphenyl ether-4,4'-diisocyanate in a solution of NMP 250Ilj
(0,0239 mol) and TDI-80/204.174
A solution of g (0,0240 mol) dissolved in 50 ml of NMP was reacted dropwise at 160° C. over 4 hours. The solution turned red-orange, but the solution viscosity only increased slightly. The intrinsic viscosity of the polymer obtained by the same treatment as in Example 3 was 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 is capable of producing a high molecular weight polyamide-imide or polyimide that can be molded 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. I can do it.

Claims (8)

[Claims] (1) A method for producing polyamide-imide or polyimide, which comprises coexisting an alkali metal salt of a polyvalent carboxylic acid represented by the general formula (I) in the reaction between a diisocyanate and a polyvalent carboxylic acid anhydride. R(COOH)_m(COOM)_n(I) However, R, M, m, and n in the above formula each have the following meanings. 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, they are bonded to R. The four carboxyl groups are bonded at positions forming two sets of acid anhydrides. H: Alkali metal. m; 0, an integer from 1 to 3. n; an integer from 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) The method according to claim 1, wherein the polycarboxylic anhydride is a tetracarboxylic dianhydride. (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 polycarboxylic acid alkali metal salt is sodium or potassium. (6) The method according to any one of claims 1 to 5, wherein the alkali metal salt of polyvalent carboxylic acid is a mono- and/or dialkali metal of 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) According to any one of claims 1 to 5, wherein the alkali metal salt of polyvalent carboxylic acid is a mono- and/or di- and/or tri- and/or tetra-alkali metal salt of tetracarboxylic acid. the method of.