Aqueous Polyurethane Compositions
AssigneeDsm IP Assets B.V.
InventorsPablo Steenwinkel, Andreas Jacobus Josine Goos, Paulus Johannes Maria Honen, Gerardus Cornelis Overbeek
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Abstract
An aqueous polyurethane composition comprising a polyurethane which is the reaction product of: (A) an isocyanate-terminated prepolymer and (B) at least one active- hydrogen chain-extending compound comprising at least 0.20 stoichiometric equivalents with respect to the isocyanate content of the isocyanate-terminated prepolymer (A), of an active-hydrogen chain-extending compound selected from the group consisting of hydrazine, hydrazine derivatives and mixtures thereof; and wherein at least 0.2 stoichiometric equivalents of the anionic or potentially anionic water-dispersing groups are neutralised with ammonia.
Claims24
An aqueous polyurethane composition comprising a polyurethane having an acid value in the range of from 4 to 150 mgKOH/g and which comprises the reaction product of:
- (A) an isocyanate-terminated prepolymer obtained by the reaction of components comprising:
- (i) at least one organic polyisocyanate;
- (ii) at least one isocyanate-reactive compound bearing anionic or potentially anionic water-dispersing groups;
- (iii) at least one isocyanate-reactive compound not comprised by (ii);
- wherein the isocyanate terminated prepolymer components are reacted in a ratio of isocyanate to isocyanate-reactive groups in the range of from 1.1:1 to 6:1;
- and
- (B) at least one active-hydrogen chain-extending compound comprising at least 0.20 stoichiometric equivalents with respect to the isocyanate content of the isocyanate-terminated prepolymer (A), of an active-hydrogen chain-extending compound selected from the group consisting of hydrazine, hydrazine derivatives and mixtures thereof;
- wherein (A) and (B) are reacted in a ratio of isocyanate to isocyanate reactive groups in the range of from 1:0.5 to 1:1;
- and
- wherein at least 0.2 stoichiometric equivalents of the anionic or potentially anionic water-dispersing groups are neutralised with ammonia.
Dependencies are inferred from the claim text.