Patent ID: 7951457

Claim:
An aqueous composition with a sediment content ≦5% comprising a polyurethane vinyl hybrid dispersion and containing ≦0.5 wt % of 1-methyl-2-pyrrolidinone by weight of the composition; wherein the polyurethane has an acid value in the range of from 25 to 65 mgKOH/g and is obtained by the reaction of: A) an isocyanate-terminated prepolymer formed from components comprising: (i) 36 to 60 wt % of at least one aromatic organic polyisocyanate; (ii) 0 to 30 wt % of at least one aliphatic organic polyisocyanate; (iii) 0 to 15 wt % of at least one isocyanate-reactive polyol bearing ionic and/or potentially ionic water-dispersing groups with a weight average molecular weight ≦500 g/mol; (iv) 0 to 10 wt % of at least one isocyanate-reactive polyol bearing non-ionic water-dispersing groups; (v) 0 to 15 wt % of at least one isocyanate-reactive polyol with a weight average molecular weight ≦500 g/mol not comprised by (iii) or (iv); (vi) 20 to 58 wt % of at least one isocyanate-reactive polyol not comprised by (iii), (iv) or (v); where (i)+(ii)+(iii)+(iv)+(v)+(vi) add up to 100 wt %; where the NCO/OH ratio is in the range of from 1.2:1 to 2.5:1; and B) at least one active-hydrogen chain extending compound; where the active-hydrogen/NCO ratio is in the range of from 0.4:1 to 1.3:1; in the presence of (a) ≦5 wt % of 1-methyl-2-pyrrolidinone by weight of polyurethane and (b) at least one reactive diluent.