Polyurethane solution for coating plastics, leather or textiles and other applications, contains polyurethane made with a chain stopper containing alkoxysilane groups and isocyanate-reactive groups

摘要

Polyurethane solutions in which at least 50% of the total amount of chain-stopper equivalents is derived from compounds containing alkoxysilane group(s) and a group which reacts with isocyanate. Polyurethane (PUR) solutions with alkoxysilane units comprising dissolved (in organic solvent) reaction products of (a) at least difunctional polyol(s) with a mol. wt. of 500-16000, (b) at least difunctional polyisocyanate(s) with a mol. wt. of 140-1500, (c) diol(s) and/or diamine(s) with a mol. wt. of 32-500, (d) compound(s) with alkoxysilane and isocyanate-reactive groups and optionally (e) monofunctional compounds with amino, alcohol or oxime groups, in which the amount of chain-stopper equivalents from (d) is at least 50% of the total stopper equivalents from (d) and (e). Independent claims are also included for (i) a process for the production of these PUR solutions by reacting components (a), (b) and optionally (c) to form an NCO-functional PUR, (ii) optionally increasing the mol. wt. by reaction with (c) and then reacting with (d) and optionally (e) to form a high-mol. wt. PUR with alkoxysilane units but no free NCO groups, with the addition of sufficient solvent before, during or after stage (a) to give a final solution with a solid content of 9-65 wt%; (ii) an alternative process involving the reaction of (a), (b) and optionally (c) to form a high-mol. wt. PUR (optionally in presence of solvent and optionally with the addition of further small amounts of (b) and/or (c) to obtain the required viscosity and hence mol. wt.), followed by the addition of a monoamino-functional alkoxysilane (d) as chain stopper.