JPH0613595B2 - Method for producing polyamide and / or polyamic acid - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a polyamide and / or a polyamic acid by reacting a polycarboxylic acid with a diisocyanate in the presence of an alkali metal salt of imide.

[Conventional technology]

It is known to produce a polyamide and / or a polyamic acid by heating a polycarboxylic acid and a diisocyanate in a solvent in the presence of a catalyst, and various catalysts have been used. For example, the author of Sanders et al. “Polyurethan
e, Chemistry and Technology ”, first column, pages 228-232, and“ Journal of Applied Polymer Science ”by Priten et al.
4 , 207 to 211 (1960), for example, tertiary amines such as triethylamine and triethylenediamine,
Alkali metal salts such as lithium acetate, sodium oleate, sodium methylate, nickel naphthenate,
Heavy metal salts such as cobalt benzoate are known, but the effect on the reaction between dicarboxylic acid and diisocyanate is small, and it has been difficult to produce a high molecular weight polymer. Further, as a catalyst for producing polyamide, polyamideimide, polyimide or the like by the reaction of carboxylic acid or acid anhydride and isocyanate, for example, US Pat.
22 and 4061623 metal alkoxides, phenoxides, lactamates described in 40214124094864 and 4094866 specifications, and cyclic phosphorous oxides described in 4156065 specifications are known, but these compounds Also, it was not possible to exhibit a sufficient catalytic effect for producing a high molecular weight polyamide from dicarboxylic acid and diisocyanate.

[Problems to be solved by the invention]

An object of the present invention is to provide a method for producing a polyamide and / or polyamic acid having a high degree of polymerization.

[Means for solving problems]

The present invention provides the following method for producing polyamide and polyamic acid.

Formula R ¹ (COOH) n (I) [In the formula, R ¹ is absent or is a divalent to tetravalent organic group, and in the case of trivalent, it is ^one of the three carboxyl groups bonded to R ¹ . Two of them are bonded to the position capable of forming an acid anhydride, and in the case of tetravalent, the four carboxyl groups bonded to R ¹ are at the positions capable of forming two sets of acid anhydrides. And n is an integer of 2 to 4. And a polycarboxylic acid represented by], wherein OCN-R ² -NCO (II) [wherein, R ² is a divalent organic group. ] By reacting with a diisocyanate represented by [Wherein R ¹ and n have the same definitions as in formula (I). ] In producing a polyamide and / or polyamic acid having a repeating unit represented by the following formula: [In the formula, R ³ is a divalent organic group, and M is a metal. ] An alkali metal salt of imide and / or a formula [Wherein, R ⁴ and R ⁵ are the same or different trivalent organic groups, and X is Or (Wherein R ⁶ is a monovalent group that does not react with a carboxyl group and an isocyanate), and Y is a direct bond. Or And M has the same definition as in formula (IV). ] It reacts in presence of the alkali metal salt of the imide represented by these, The manufacturing method of the polyamide and / or polyamic acid characterized by the above-mentioned.

The polymer produced by the present invention can be widely used for fibers, films, papers, molded articles, varnishes, adhesives, etc. by utilizing its excellent heat resistance, electrical insulation, mechanical properties and the like. .

The divalent to tetravalent organic group R ¹ in the formula (I) and the divalent organic group R ² in the formula (II) are preferably aliphatic groups, aromatic groups, alicyclic groups or heterocyclic groups. However, these may be substituted with a group or atom that does not substantially react with the carboxyl group and the isocyanate group, for example, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, a halogen atom and the like. Further, two or more kinds of these groups may be bonded, for example, at carbon-carbon, or alkylene. Or Etc. (in the formula, R is an alkyl group, a cycloalkyl group or an aryl group, and when two are bonded, they may be different).

Examples of the polycarboxylic acid represented by the formula (I) are described in JP-A-57-
151615, JP-A-57-179223, JP-A-58-13629 and JP-A-58-67723. Examples of n = 2 in the formula (I) are fumaric acid, malonic acid, adipic acid, terephthalic acid, isophthalic acid, diphenyl ether-4,4'-dicarboxylic acid and pyridine-2,6-dicarboxylic acid. . Examples of n = 3 are butane-1,2,4-tricarboxylic acid, benzene-1,2,4-tricarboxylic acid (trimellitic acid), and naphthalene-1,2,4-tricarboxylic acid.
Examples of n = 4 include butane-1,2,3,4-tetracarboxylic acid, cyclobutane-1,2,3,4-tetracarboxylic acid,
Benzene-1,2,4,5-tetracarboxylic acid (pyromellitic acid), 3,3 ', 4,4'-benzophenone tetracarboxylic acid, 3,3', 4,4'-diphenyl ether tetracarboxylic acid . These polyvalent carboxylic acids may partially contain an intramolecular acid anhydride group. You may use 2 or more types of polyvalent carboxylic acid.

Examples of the diisocyanate represented by the formula (II) are disclosed in JP-A-57-151615, JP-A-57-179233, and JP-A-58-13629.
And JP-A-58-67723. Typical examples are 1,2-diisocyanateethane, cyclohexane-
1,4-diisocyanate, phenylene-1,3-diisocyanate, toluylene-2,4-diisocyanate, toluylene-
2,6-diisocyanate, diphenylmethane-4,4'-diisocyanate and diphenylether-4,4'-diisocyanate. Two or more kinds of diisocyanates can be used.

By combining compounds having various skeletons and bonds as described above as the polyvalent carboxylic acid and diisocyanate represented by the above formulas (I) and (II), the processability, chemical and thermal properties of the resulting polymer can be improved. , Electrical properties and mechanical properties can be freely controlled.

R ³ in the above formula (IV) is a divalent organic group, preferably an aliphatic group, an aromatic group, an alicyclic group or a heterocyclic group, which substantially reacts with a carboxyl group and an isocyanate group. It may be substituted with a group or atom which is not included, for example, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, a halogen atom and the like.

R ⁴ and R ⁵ in the above formula (V) are the same or different 3
A valent organic group, preferably an aromatic group, an alicyclic group or a heterocyclic group, which is a group or atom which does not substantially react with a carboxyl group and an isocyanate group, such as an alkyl group, a cycloalkyl group or an aryl group. It may be substituted with a group, an alkoxy group, a halogen atom or the like.

Representative examples of the imide alkali metal salt represented by the formula (IV) include lithium succinimide, sodium succinimide, potassium succinimide, imidorubidium succinate, cesium imidocesium, glutaric acid lithium, and glutaric acid. Sodium acid imide, potassium glutaric acid imide, rubidium glutaric acid, cesium glutaric acid, imide lithium maleic acid, sodium maleic acid imide, potassium maleic acid imide, imide rubidium maleic acid, imide cesium maleic acid, sodium phthalic acid imide, phthalic acid Representative examples of the imide alkali metal salt of potassium imide imide, rubidium phthalate imide, and cesium imide phthalate are benzophenone-3,4-dicarboxyanhydride-2 '. 4'imide, benzophenone-3,4 dicarboxylate cyan hydride -
3 ', 4'-acid imide potassium, benzophenone-3,4-dicarboxyanhydride-3', 4'-acid imide, biphenyl-3,4-dicarboxyanhydride-3 ', 4'
-Lithium acid imide, biphenyl-3,4-dicarboxyanhydride-3 ', 4'-imidoniumylium, biphenyl-3,4-dicarboxyanhydride-3', 4'-
Acid imide potassium, diphenyl ether-3,4-dicarboxyanhydride-3 ', 4'-acid imide lithium,
Diphenyl ether-3,4-dicarboxyanhydride-3 ', 4'-acid imide sodium, diphenyl ether-3,4-dicarboxyanhydride-3', 4'-acid imide potassium, diphenylsulfone-3,4-di Carboxyanhydride-3 ', 4'-lithium imide imide, diphenylsulfone-3,4-dicarboxyanhydride-
3 ', 4'-sodium acid imide, diphenyl sulfone-
3,4-Dialboxianhydride-3 ', 4'-imizopotassium acid. Of these, potassium phthalimide, sodium phthalimide and mixtures thereof are particularly preferred.

The reaction of the polyvalent carboxylic acid and the diisocyanate is carried out in the coexistence of the imide alkali metal salt, generally in an anhydrous organic polar solvent, under an inert gas such as a stream of nitrogen,
Alternatively, while removing the CO ₂ gas generated as a by-product under reduced pressure, about 20
It is carried out by heating at a temperature of ~ 300 ° C, preferably 50-250 ° C for about 1-20 hours.

As the organic solvent, for example, N, N'-dimethylacetamide, N, N'-dimethylacetamide, N, N'-dimethylformamide, N-methylpyrrolidone, hexamethylphosphoric triamide, dimethylsulfoxide and the like are used.
Further, these organic polar solvents can be diluted with other organic non-polar solvents such as benzene, toluene, xylene, cresol, cyclohexane, pentane, hexane, heptane, methylene chloride, tetrahydrofuran, cyclohexanone, dioxane and the like.

In the method of the present invention, when a polyvalent carboxylic acid and a diisocyanate are reacted in the presence of an imide alkali metal salt, the reaction system may or may not be in a solution or suspension state. The addition method of the alkali metal salt, the addition order and the addition timing can be arbitrarily selected,
In either case, the amide bond formation reaction is significantly accelerated. Therefore, for example, by mixing and heating a polyvalent carboxylic acid, a diisocyanate and an imide alkali metal salt in a solvent-free state, it is possible to produce a high molecular weight high foam in an extremely short time. Generally, in an organic polar solvent, the monomer concentration [(dicarboxylic acid + diisocyanate) g / solvent] is mixed in the range of 50 to 400 g / to facilitate handling of the polymer, but polymerization at a high concentration When the above is started, it is preferable to successively add the solvent to the extent that stirring is not hindered during the polymerization. Further, in the method of the present invention, the molar ratio of the diisocyanate to the polycarboxylic acid is lower than that in the case where the monoalkali metal salt of the carboxylic acid is not used, but in general, there are few side reactions and the production of a higher molecular weight polyamide. Can be done, but from 0.70
It is preferable that it is substantially equivalent in the range of 1.30.
The range of 0.90 to 1.15 is preferable.

The amount of the imide alkali metal salt added is preferably 0.5 to 20 mol%, particularly preferably 1 to 10 mol% based on the polycarboxylic acid.

〔Example〕

Hereinafter, the method of the present invention will be described with reference to examples, but the present invention is not limited thereto.

In the following examples, the logarithmic viscosity is a value measured at 30 ° C. for a 0.1 g / 100 ml concentrated sulfuric acid solution. Logarithmic viscosity (ηinh) is Where t = solution flow-down time (seconds), t ₀ = solvent flow-down time (seconds), C = polymer concentration in solvent (g / 100 ml).

In addition, polyvalent carboxylic acids, diisocyanates, catalysts, solvents and the like described in the examples are shown by the following abbreviations.

IPA: isophthalic acid TPA: terephthalic acid TDI-100: toluylene-2,4-diisocyanate TDI-80 / 20: toluylene-2,4-diisocyanate / toluylene-2,6-diisocyanate mixture (molar ratio = 80: 2
0) PI-Na: sodium phthalimide PI-K: potassium phthalimide NMP: N-methyl-2-pyrrolidone TMSO ₂ : sulfolane (tetramethylsulfone) Example 1 Stirrer, dropping funnel, reflux condenser, thermometer , IPA 9.97g (0.060mol), TPA in 500ml flask equipped with nitrogen inlet
9.97g (0.060mol), and anhydrous NMP 370ml, TDI-80 / 2
0 21.32 g (0.1224 mol) and PI-Na 0.4056 g (0.0024 mol) were inserted. While stirring, the mixture was heated on an oil bath in a nitrogen atmosphere and reacted at 120 ° C. for 2 hours. After the generation of carbon dioxide gas was not observed, heating was stopped and the mixture was cooled to room temperature. The reaction solution was a fairly viscous pale yellowish brown color. This solution was poured into 1500 ml of methanol to precipitate the produced polymer with stirring, and further washed with methanol and water. Then, it was dried under a reduced pressure of 1 to 2 mmHg at 130 ° C. for 3 hours to obtain 29.0 g of light yellowish brown powder. The logarithmic viscosity of this polymer is
It was 1.1.

Comparative Example 1 Example 1 except that potassium phthalimide was not allowed to coexist.
Was repeated. The viscosity of the solution hardly increased. The same treatment as in Example 1 was carried out to obtain 3.5 g of a pale yellow powder. The logarithmic viscosity of this polymer was 0.39.

Examples 2 to 4 and Comparative Examples 2 to 4 The reaction was carried out under the types of monomers, the types of catalysts and the types and amounts of solvents, and the reaction conditions shown in Table 1. The results are shown in Table-1.

[Effects of the Invention] As is clear from the above Examples and Comparative Examples, by using an acid imide alkali metal salt as a catalyst, high polymerization that cannot be obtained from a polyvalent carboxylic acid and an isocyanate using a conventional catalyst. Degrees of polyamide and / or polyamic acid are obtained.

Claims (1)

[Claims] 1. A compound represented by the formula R ¹ (COOH) n (I) [wherein R ¹ is absent or is a divalent to tetravalent organic group, and in the case of trivalent, 3 is bonded to R ¹ 2 of the 1 carboxyl groups are bonded to positions capable of forming an acid anhydride, and in the case of tetravalent, the 4 carboxyl groups bonded to R ¹ are 2 groups of acid anhydrides. It is bonded to a position where it can be formed, and n is an integer of 2 to 4. And a polycarboxylic acid represented by], wherein OCN-R ² -NCO (II) [wherein, R ² is a divalent organic group. ] By reacting with a diisocyanate represented by [Wherein R ¹ and n have the same definitions as in formula (I). ] In producing a polyamide and / or polyamic acid having a repeating unit represented by the following formula: [In the formula, R ³ is a divalent organic group, and M is an alkali metal. ] An alkali metal salt of imide and / or a formula [Wherein, R ⁴ and R ⁵ are the same or different trivalent organic groups, and X is Or (Here, a monovalent group that does not react with the R ⁶ carboxyl group and the isocyanate), and Y is a direct bond. Or And M has the same definition as in formula (IV). ] It reacts in presence of the alkali metal salt of the imide represented by these, The manufacturing method of the polyamide and / or polyamic acid characterized by the above-mentioned.