Heat-curing sealant compositions having fast skin formation and high tensile strength

摘要

The present invention relates to heat-curing sealant compositions including at least epoxy resin, dicyanodiamide or an amine complex of a Lewis acid, polyurethane polymer (PUP) containing isocyanate groups and polyaldimine. These single component sealant compositions are characterized by a rapid skin formation and high tensile strength. Because of the short skin formation time, said compositions are optimally suitable for use as sealants in autobody work because they can be excellently layered on top of same.

主权项

1. A heat-curing sealant composition, comprising:
at least one epoxy resin (A) with an average of more than one epoxy group per molecule; at least one heat-activatable curing agent or accelerator (B) selected from the group consisting of dicyanodiamide and an amine complex of a Lewis acid; at least one polyurethane polymer (PUP) containing isocyanate groups; and at least one polyaldimine (PA); wherein: a weight ratio of the epoxy resin (A) to the polyurethane polymer (PUP) containing isocyanate groups is in a range between 0.1:1 and 0.5:1; the polyurethane polymer (PUP) is obtained from a reaction between at least one polyol and at least one polyisocyanate; and the polyol has an average molecular weight of 250 to 30,000 g/mol.