초록

The present invention relates to a novel chain extender for use in making moldings. The chain extender broadly comprises the reaction product of an aromatic diamine and a cyclic carboxylic acid dianhydride.

대표청구항 ▼

A process for the production of moldings comprising reacting an organic polyisocyanate, an organic active hydrogen containing material having a molecular weight of from 1000 to 8000 and containing at least two active hydrogen groups, and a chain extender in a closed mold, said chain extender compris

A process for the production of moldings comprising reacting an organic polyisocyanate, an organic active hydrogen containing material having a molecular weight of from 1000 to 8000 and containing at least two active hydrogen groups, and a chain extender in a closed mold, said chain extender comprising the reaction product of (a) an aromatic diamine which contains at least one non-reactive substituent in the ortho position to a first amino group and at least one other non-reactive substituent in the ortho position to a second amino group, and (b) a cyclic carboxylic acid dianhydride at a molar ratio of component (a) to component (b) of from 3:1 to 25:1.