Process for production of polycarbodiimide resin powder

Abstract

A process for producing a polycarbodiimide resin powder, which includes reacting an organic diisocyanate in the presence of a carbodiimidization catalyst in a solvent to produce a polycarbodiimide resin and obtaining the resin in a powder form, where the organic diisocyanate is represented by the following formula ##STR1## where R.sub.1 is a lower alkyl group or a lower alkoxyl group, or ##STR2## where R.sub.2 and R.sub.3 are independently a hydrogen atom, a lower alkyl group or a lower alkoxyl group, and X is an oxygen atom or a methylene group, or ##STR3## where R.sub.4 and R.sub.5 are independently a hydrogen atom, a lower alkyl group or a lower alkoxyl group; the solvent is a mixed solvent of a good solvent to polycarbodiimide resin and a poor solvent to the resin, having a precipitation number of 30-80; and when the reaction has reached a certain stage, the reaction system is cooled to make the system a slurry of a polycarbodiimide, and then the polycarbodiimide is obtained in a powder form.