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US 5,393,839 AGranted
Curable composition containing polyepoxide and polycarbodiimide
AssigneeNippon Paint Co., Ltd.
InventorNorikazu Iwamoto
Life of this patent
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Abstract
The present invention provides a curable composition which employs the oxazolidineimine ring-forming reaction between an epoxide and a carbodiimide for curing and which cures under a mild condition in a short period of time with little side reaction to obtain a polycarbodiimide resin having good strength, heat resistance and processability. The curable composition of the present invention comprises (a) a polycarbodiimide, (b) a polyepoxide and (c) a zinc halide or a mixture of zinc halide and an onium salt as a catalyst.
Claims1
A curable composition comprising:
- (a) a polycarbodiimide having at least 2 carbodiimide groups and a number average molecular weight of 250 to 10,000, prepared by polycondensation of an organic polyisocyanate in the presence of a carbodiimide promoting agent;
- (b) a polyepoxide having at least 2 epoxy groups and a number average molecular weight of 200 to 50,000;
- and
- (c) as a catalyst, a zinc halide or a mixture of a zinc halide and an onium salt represented by ##STR2## wherein Z represents a nitrogen atom or a phosphorous atom, R.sup.1 to R.sup.4, which are the same or different, each represent an organic group selected from the group consisting of aliphatic hydrocarbon groups, alicyclic hydrocarbon groups and aromatic hydrocarbon groups, and may form a ring in combination, and X represents a halogen atom
- characterized in that, when cured, said carbodiimide groups react with said epoxy groups to form oxazolidineimine groups.
2 more elements
Dependencies are inferred from the claim text.