Patent ID: 6166165
Filing Date: 2000-12-26
Classification: C08G

Abstract:
A process for producing a water-dispersible polyurethane comprising:(a) providing a sulfonate-substituted polyester which is substituted with an average of at least two hydroxyl groups per molecule wherein said sulfonated-substituted polyester is formed by:forming an ethylenically unsaturated polyester which is substituted with at least two hydroxyl groups by condensation polymerization of an ethylenically unsaturated diol with a diacid or anhydride; andsulfonating said ethylenically unsaturated polyester by reacting it with a sulfonating agent under conditions such that said sulfonating agent reacts with said ethylenic unsaturation and sulfonates said polyesters;(b) reacting said sulfonate-substituted polyester with one or more polyisocyanate compounds to form a sulfonate-substituted prepolymer substituted with at least two isocyanate groups; and(c) reacting said prepolymer with one or more chain extenders free of salt-forming groups, wherein said one or more chain extenders are selected from the group consisting of hydrazine, alkyl and aromatic polyols, and alkyl and aromatic diamines and triamines, wherein the alkyl compounds contain a total of 2 to 12 carbon atoms and the aromatic compounds contain 6 to 10 carbon atoms, thereby forming a polyurethane, wherein said polyester is sufficiently sulfonate-substituted so that said polyurethane is water-dispersible.