| 摘要 |
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 <IMAGE> (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.
|
