Patent ID: 6410095
Filing Date: 2002-06-25
Classification: C08G,C09D,C09K,C14C

Abstract:
A method for making a blister-free coating comprising:(1) applying a substantially solvent-free binder composition to a substrate, the solvent-free binder composition comprising: a) a polyisocyanate component containing heteroallophanate groups and having aromatically-bound isocyanate groups, i) an NCO content of 3 to 16% by weight based on the weight of the polyisocyanate component, ii) an average functionality of 1.8 to 4, iii) an allophanate group content (calculated as C2HN2O3, MW: 101) of 5 to 35% by weight, based on the weight of the polyisocyanate component, wherein the allophanate groups are prepared from urethane groups that are the reaction product of a linear aliphatic diisocyanate having an isocyanate group content of 30 to 60% by weight, based on the weight of the linear aliphatic diisocyanate, with a hydroxyl component having a hydrocarbon chain of 2 to 23 carbon atoms and an average functionality of less than 1.5 at an NCO/OH equivalent ratio of 1.0:1.0 to 0.5:1.0, iv) a hydrocarbon chain content of 10 to 65% by weight, based on the weight of the polyisocyanate component, wherein the hydrocarbon chains are attached to allophanate groups via oxygen and have an average of 2 to 23 carbon atoms and v) a distillable diisocyanate content of less than 0.5% by weight, based on the weight of the polyisocyanate component, and b) an isocyanate-reactive component; and (2) curing the composition.