Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
226 words
A process for the preparation of an aqueous polyurethane polyurea dispersion which comprises reacting (a) an NCO-prepolymer having an average NCO-functionality of 2 to 2.3, an average molecular weight of about 700 to 5000 and prepared from (i) organic polyhydroxyl compounds and, optionally, organic monohydroxyl compounds and (ii) an excess quantity of organic polyisocyanates and, optionally monoisocyanates with (b) organic polyamines having an (average) amine functionality of 2,05 to about 3, an (average) molecular weight of 60 to about 2000 and containing primary or secondary amino groups or mixtures thereof at an equivalent ratio of isocyanate groups of component (a) to the amino groups of component (b) of 1.05:1 to about 7:1, in the presence of a water-miscible weakly polar solvent inert to isocyanate groups and having a boiling point at normal pressure below 100° C., either component (a) or component (b) or both containing carboxylate groups and/or nonionic hydrophilic groups in a quantity sufficient to guarantee the dispersibility of said polyurethane polyurea in water, subsequently converting the resulting solution of the reaction product in solvent into an aqueous dispersion by adding water and optionally removing the solvent by distillation, characterized in that the reactants and the quantitative ratios used are selected such that the resulting reaction products have an NCO-functionality of 2.2 to about 3 and an NCO-content of about 0.01 to 5% by weight.
Claim 2
Dependent Claim
226 words
A process for the preparation of an aqueous polyurethane polyurea dispersion which comprises reacting (a) an NCO-prepolymer having an average NCO-functionality of 2 to 2.3, an average molecular weight of about 700 to 5000 and prepared from (i) organic polyhydroxyl compounds and, optionally, organic monohydroxyl compounds and (ii) an excess quantity of organic polyisocyanates and, optionally monoisocyanates with (b) organic polyamines having an (average) amine functionality of 2,05 to about 3, an (average) molecular weight of 60 to about 2000 and containing primary or secondary amino groups or mixtures thereof at an equivalent ratio of isocyanate groups of component (a) to the amino groups of component (b) of 1.05:1 to about 7:1, in the presence of a water-miscible weakly polar solvent inert to isocyanate groups and having a boiling point at normal pressure below 100° C., either component (a) or component (b) or both containing carboxylate groups and/or nonionic hydrophilic groups in a quantity sufficient to guarantee the dispersibility of said polyurethane polyurea in water, subsequently converting the resulting solution of the reaction product in solvent into an aqueous dispersion by adding water and optionally removing the solvent by distillation, characterized in that the reactants and the quantitative ratios used are selected such that the resulting reaction products have an NCO-functionality of 2.2 to about 3 and an NCO-content of about 0.01 to 5% by weight.
Claim 3
Dependent Claim
41 words
The process of claim 1 wherein the average molecular weight of the organic polyhydroxyl compound (i) and the amounts of (i) and (ii) are selected so that the resulting reaction products contain about 5 to 20% by weight of urethane groups.
Claim 4
Dependent Claim
46 words
A process for the production of a coated substrate which comprises (1) preparing an aqueous polyurethane polyurea dispersion in accordance with claim 1 and (2) applying a coating composition comprising the aqueous polyurethane polyurea dispersion prepared in step 1) to a substrate and curing said coating.
Claim 5
Dependent Claim
13 words
The process of claim 3 wherein said substrate is a hard, inflexible substrate.