LOW NWP AQUEOUS POLYURETHANE COMPOSITION

摘要

An aqueous composition with a sediment content = 5%, comprising a polyurethane dispersion wherein the polyurethane has an acid value in the range of from 25 to 65 mgKOH/g and comprises (i) 36 to 60 wt% of at least one aromatic polyisocyanate and where the polyurethane is prepared in the presence of (a) = 5 wt% of 1-methyl-2-­pyrrolidinone by weight of the polyurethane , (b) 5 to 100 wt% of 1 -ethyl-2-pyrrolid i none by weight of polyurethane and (c) water.