Mitsui Toatsu Chemicals, Incorporated

Toshihiro Toyoda

Kazumi Mizutani

Masanori Osawa

Motoo Kawamata

Masahiro Kouno

Kohei Shizuka

Masayoshi Itoh

Hiromi Nakano

Masahiro Kono

A polyamide and/or polyimide is prepared by using N,N'-dimethylethyleneurea or N,N'-dimethylpropyleneurea as a solvent upon polycondensation of a polycarboxylic acid and a diisocyanate at a temperature above 100.degree. C. in the presence of an alkali metal carbonate, alkali metal hydrogencarbonate, alkali metal hydroxide or an alkali metal salt of a polycarboxylic acid.

Catalytic preparation of polyamide or polyamide-polymide with

Disclosed is a process for the preparation of polyamide compounds by reacting at least one polycarboxylic acid with at least one diisocyanate in the presence of a catalyst comprising at least one mono-alkali metal salt of dicarboxylic acid. The polyamide compounds prepared by this process have a substantially linear configuration and a high degree of polymerization and, therefore, are suitable for the manufacture of fibers, films and molded articles.

Process for the preparation of polyamide compounds by the reaction of

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Yokohama, Japan

Toshihiro Toyoda