Epoxide advancement process.

摘要

Coating compositions containing aqueous dispersion of higher molecular weight epoxy resin are produced by advancing the molecular weight of an aqueous dispersion of a low molecular weight epoxy resin having a number average molecular weight between about 360 and 2 000. The water dispersed low molecular weight epoxy resins are advanced in molecular weight by coreaction with a diphenol at temperatures above about 105 DEG C and at pressures above about 34 475 N/m<2> over atmospheric (5 psig) to produce the aqueous dispersed high molecular weight epoxy resin. The aqueous dispersed high molecular weight epoxy resin can be further copolymerized with ethylenic monomers, if desired, to produce an acrylic epoxy emulsion binder useful in protective coatings.