Coagulation of post-crosslinkable, aqueous polyurethane dispersions for coating, textile treatment and fibre-bonding applications involves precipitation by heating to give a stable crosslinked polymer or gel

摘要

A method for the coagulation of post-crosslinkable polyurethane (PUR) dispersions involves precipitation by thermal treatment at 50-120 deg C with the formation of a stable, at least partly crosslinked polyurethane or gel. Independent claims are also included for:- (1) coagulatable, post-crosslinkable PUR dispersions obtained by this method in the form of aqueous dispersions or emulsions containing reaction products of (a) di- or poly-isocyanates, (b) poly-hydroxy compounds with mol. wts. of up to 16000, (c) ionic, potentially ionic and/or non-ionic hydrophilising agents, (d) isocyanate blocking agents, (e) optional low-mol. wt. mono-, di- or tri-amine chain-stoppers, -extenders or -branchers together with (f) polyamine crosslinkers; (2) coagulates and water vapour-permeable coagulates obtained by this method.