Aqueous polyurethane-phenolic-formaldehyde resin emulsions for use as adhesives, primers and surface coatings

Abstract

Stable aqueous emulsions useful as coatings, primers for promoting vinyl plastisol adhesion to metal, and adhesives for bonding vinyl to metal with high environmental resistance, are described, which comprise: (a) aqueous polyurethane latexes substantially free of emulsifier and containing about 0.02 to 1% of a salt type group from the class consisting of ##STR1## (b) an aqueous casein cocondensed phenolic-formaldehyde resin emulsion; and (c) an ionic fluorocarbon surfactant; in proportions of about 25 to 99% (a), about 1 to 50% (b) and about 1 to 10,000 parts per million (c), by weight of the total composition. Such emulsions are useful per se as coatings and primers and single package adhesives. Two-package adhesives having superior properties are provided, in which the foregoing emulsions as part A are cured by a crosslinker, part B, in a ratio A:B in the range from about 100 to 2.5A:1B. The crosslinking agents may be glyoxal, melamineformaldehyde resins, or any formaldehyde donor.

Dependencies are inferred from the claim text.