Patent ID: 7772307

Claim:
A water dispersible polyisocyanate composition having (a) an aliphatic polyisocyanate or a mixture of aliphatic polyisocyanates bearing primary and/or secondary isocyanate groups, and containing isocyanurate groups, and/or biuret groups, and/or oxadizine-1,3-dione-5-imine groups, and/or uretdione groups; and (b) a reaction product of component (a) with a mixture of a polyoxyalkylene amine and a polyoxyalkylene alcohol containing 65-87% of ethylene oxide units, based on a number-averaged molecular weight of the mixture of the polyoxyalkyene amine and polyoxyalkylene alcohol; wherein the composition is prepared by the steps of (1) forming an intermediate composition comprising urea functional groups by mixing 97-94% of component (a), based on the weight of the compositions, with 2-3% of a component (c) consisting of polyoxyalkylene amine with an NH 2 equivalent weight of 600-1,050 gram per equivalent number, selected from the group consisting of (c1) polyoxyalkylene monoamine(s), (c2) polyoxyalkylene diamine(s), and (c3) a mixture of (c1) and (c2); and 1-3% of a component (d) consisting of polyoxyalkylene alcohol with an OH equivalent weight of 300-500 gram per equivalent number, selected from the group consisting of (d1) polyoxyalkylene diol(s), (d2) polyoxyalkylene triol(s), and (d3) a mixture of (d1) and (d2); and then (2) continuous heating of the intermediate composition under conditions and for a time to convert sufficient of the urea functional groups to biuret functional groups so as to from the water dispersible polyisocyanate with a viscosity that is less than 132% of the viscosity of the intermediate composition.