AQUEOUS COMPOSITION WITH IMPROVED ELONGATION AT BREAK

摘要

An aqueous polymer composition which when in the form of a film shows excellent elongation at break comprising (i) 5 to 30 wt. % of polyurethane where the acid value of the polyurethane is between 3 to 40 mg KOH/g; (ii) 70 to 95 wt. % of vinyl polymer comprising 20 to 90 wt. % of vinyl polymer with Tg<20° C.; 10 to 80 wt. % of vinyl polymer with Tg≧20° C.; where at least one of the vinyl polymers contains acid functional groups with acid value in the range of from 15 and 240 mg KOH/g.

主权项

1. An aqueous polymer composition comprising
(i) 5 to 30 wt. % of polyurethane obtained by the reaction of:
(a)
(1) 9 to 31 wt. % of at least one polyisocyanate;(2) 0 to 8 wt. % of at least one isocyanate-reactive compound with a weight average molecular weight in the range of from 50 to 500 g/mol, containing ionic or potentially ionic water-dispersing groups;(3) 0 to 91 wt. % of at least one isocyanate-reactive compound with a weight average molecular weight in the range of from 501 to 5000 g/mol containing ionic or potentially ionic water-dispersing groups;(4) 0 to 91 wt. % of at least one isocyanate-reactive compound with a weight average molecular weight in the range of from 501 to 5000 g/mol not comprised by (3);where (3) and (4) add up to 57 to 91 wt. %;(5) 0 to 10 wt. % of at least one isocyanate-reactive compound with a weight average molecular weight in the range of from 50 to 500 g/mol not comprised by (2);where (1), (2), (3), (4) and (5) add up to 100%; and(b) at least one chain-extending compound;
where the acid value of the resulting polyurethane (i) is between 3 to 40 mg KOH/g; (ii) 70 to 95 wt. % of vinyl polymer comprising
(c) 20 to 90 wt. % of vinyl polymer with Tg<20° C.;(d) 10 to 80 wt. % of vinyl polymer with Tg≧20° C.;wherein (c) and (d) add up to 100%;where at least one of (c) and (d) contains acid functional groups with an acid value in the range of from 15 to 240 mg KOH/g; andwherein (i) and (ii) add up to 100%.