Aqueous polyurethane dispersions

摘要

Polyurethane (I), obtained by the reaction of NCO (free isocyanate group) containing prepolymer (formed from at least polyester polyol) with at least NCO group related reactive polysiloxane, at least NCO group related reactive amine and water, where the molar ratio of the prepolymer to the used hydroxy functional compounds to the polyisocyanate is 1:1.1-1:2.5 (preferably 1.1:1-1:1.7), is new. Polyurethane (I), obtained by the reaction of NCO group containing polymer (formed from (a1) polyester polyol (preferably polycarbonate polyol), carbonate group free polyester glycol, polyester carbonate polyol (preferably polyester diol) with determined average molecular weight of 500 (preferably 800-4000) g/mol; (a2) at least one of (a1), ester group-free polyether polyol, preferably polyalkylene glycol as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol and polyether mix (preferably compounds containing from the group of ethylene oxide, propylene oxide, tetramethylene oxide and/or hexamethylene oxide) with determined average molecular weight of 500 (preferably 800-4000) g/mol, preferably polyether diol; (a3) at least polyol (preferably diol) with a molecular weight of less than 500 g/mol, which carries one or more (potential) ionic group (preferably one or more carboxylate group); (a4) at least an aliphatic polyisocyanate (preferably diisocyanate), preferably with a molar weight less than 500 (preferably 168-262) g/mol; (a5) optionally non ionic (preferably polyol), preferably diol with a molecular weight of less than 500 (preferably 61-499) g/mol; or (a6) mono alcohol) with (b) at least NCO group related to reactive polysiloxane with a determined molar weight of less than 1500 g/mol, with 1-6 (preferably (1-3) NCO group related reactive amino and/or hydroxyl group (preferably amino group); (c) at least NCO group related reactive amine with a median amino functionality of 1-6 and molar weight of less than 500 g/mol (as certain median number molar weight) that can be replaced by hydroxyl group, sulfo group and/or carboxyl group; and (d) water, where the molar ratio of the prepolymer to the used hydroxy functional compounds to the polyisocyanate is 1:1.1-1:2.5 (preferably 1.1:1-1:1.7), is new. Independent claims are also included for: (1) an aqueous dispersion comprising at least one of polyurethane; (2) preparation of (I); (3) polyurethane system comprising the component (A) and at least one of the components (A1) and (B), where (A) comprises at least polyurethane or polyurethane dispersion, (A1) comprises optionally one or more polymer dispersion such as polyacrylate dispersion or polyurethane dispersion and (B) comprises optionally water dispersable, aliphatic or cycloaliphatic polyisocyanate with NCO-functionality of at least 2 (preferably 2.3-6); (4) procedure for coating substrates comprising application of polyurethane or polyurethane system on substrates; and (5) substrates, coated with at least with one of polyurethane, aqueous polyurethane dispersion or polyurethane system.