Low viscosity, ethylenically unsaturated polyurethanes containing allophanate groups

Abstract

The present invention relates to ethylenically unsaturated polyurethanes which are substantially free from isocyanate groups and have a) a content of .beta.,.gamma.-ethylenically unsaturated ether groups (calculated as C.dbd.C, MW 24) incorporated through allophanate groups of 0.5 to 10% by weight, b) an allophanate group content (calculated as N.sub.2 C.sub.2 HO.sub.3, MW 101) of 1 to 20% by weight and c) a total content of ethylenically unsaturated groups of (calculated as C.dbd.C, MW 24) of 1 to 15% by weight. The present invention also relates to ethylenically unsaturated polyisocyanates which contain allophanate groups and have i) an NCO content of 5 to 25% by weight, ii) a content of .beta.,.gamma.-ethylenically unsaturated ether groups (calculated as C.dbd.C, MW 24) incorporated through allophanate groups of 0.5 to 15% by weight and iii) an allophanate group content (calculated as N.sub.2 C.sub.2 HO.sub.3, MW 101) of 1 to 30%. Finally, the present invention relates to one-component coating compositions containing the ethylenically unsaturated polyurethanes according to the invention.

Dependencies are inferred from the claim text.