MULTI-LAYER COATING SYSTEM INCLUDING HYDROXYL MODIFIED POLYURETHANE DISPERSION BINDER

摘要

PROBLEM TO BE SOLVED: To reduce the amounts of organic solvents in the coating systems.SOLUTION: A dispersion comprises: (a) a hydroxyl-functional polyurethane resin comprising the reaction product of: (i) an isocyanate pre-polymer intermediate, which comprises the reaction product of an isocyanate and a compound comprising at least one active hydrogen; and (ii) a chain extender compound comprising at least two amine groups and one hydroxyl group, wherein the two amine groups are more reactive with isocyanate than the hydroxyl group; wherein the hydroxyl groups of the hydroxyl-functional polyurethane are positioned on the main chain of the polyurethane; and (b) water.