Patent ID: 8211954
Filing Date: 2012-07-03
Classification: C08G,C09D

Abstract:
1. A polyurethane comprising allophanate groups and obtained by reacting the following components comprising: (a) at least one organic aliphatic, aromatic or cycloaliphatic di- or polyisocyanate, (b) at least two different compounds (b1) and (b2), (c) optionally, at least one compound having exactly two groups reactive toward isocyanate and no unsaturated groups, (d) optionally, at least one compound having at least three groups reactive toward isocyanate and no unsaturated groups, and (e) optionally, at least one compound having exactly one group reactive toward isocyanate and no unsaturated groups, wherein compound (b1) has exactly one group reactive toward isocyanate and exactly one unsaturated group capable of free radical polymerization, the unsaturated group being an ester of an α,β-unsaturated carboxylic acid, and compound (b2) has exactly one group reactive toward isocyanate and at least two unsaturated groups capable of free radical polymerization, the unsaturated groups capable of free radical polymerization being esters of α,β-unsaturated carboxylic acids, and wherein component (a) is reacted first with component (b1), thereby forming a polyisocyanate containing allophanate groups, which polyisocyanate containing allophanate groups is then reacted with component (b2).