Aqueous dispersions
AssigneeICI Americas Inc.
InventorsRichard G. Coogan, Razmik Vartan-Boghossian
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Abstract
An aqueous polymer dispersion containing a water-dispersible polyurethane and a vinyl polymer, the polyurethane being the product of reacting an active hydrogen containing chain extender with a water-dispersible isocyanate-terminated polyurethane prepolymer derived from a polyisocyanate component containing at least 5% by weight of 2,4'-diphenylmethane diisocyanate. The dispersions are useful as coating compositions.
Claims16
An aqueous polymer dispersion containing a water-dispersible polyurethane and a vinyl polymer, the polyurethane being the product of reacting an active hydrogen containing chain extender with a water-dispersible isocyanate-terminated polyurethane derived from a polyisocyanate component comprising a mixture of the 2,4'- and 4,4'-isomers of diphenylmethane diisocyanate containing from 5 to 70% by weight of the 2,4'-isomer.
A dispersion according to claim I wherein the prepolymer is the reaction product of:
- (i) a polyisocyanate component comprising a mixture of the 2,4'- and 4,4'-isomers of diphenylmethane diisocyanate containing from 5 to 70% by weight of the 2,4'-isomer, and
- (ii) an active hydrogen component comprising at least one polymeric polyol having a molecular weight in the range 400 to 6000 and optionally one or more low molecular weight polyols and polyamines having a molecular weight below 400, at least one of the polyols or polyamines containing ionic or potentially ionic groups.
An aqueous polymer dispersion containing a water-dispersible polyurethane and a vinyl polymer, the polyurethane being the product of reacting an active hydrogen containing chain extender with a water-dispersible isocyanate-terminated polyurethane prepolymer derived from a polyisocyanate component comprising:
- (i) from 10 to 60% by weight of toluene diisocyanate, and
- (ii) from 90 to 40% by weight of a mixture of 4,4'- and 2,4-diphenylmethane diisocyanates containing from 5 to 70% by weight of the 2,4'-isomer.
Dependencies are inferred from the claim text.