BASE FOR A GRAFT POLYMER, NOVEL GRAFT POLYMER COMPOSITIONS, SOLVENT AND WATER-REDUCIBLE COATINGS INCORPORATING THE NOVEL GRAFT POLYMERS, AND PROCESSES FOR MAKING THEM

摘要

Provides new and improved water-reducible coating compositions and methods of making them. Three preferred processes are disclosed. These differ in the manner of incorporating and chemical nature of an extender polymer. Broadly, the process of the invention is one for forming an aqueous dispersion of a fluent resinous composition ofP Pa. a mixture in an organic solvent ofPP(i) an ionizable graft polymer of an epoxy resin and an addition polymerized resin, the addition polymerized resin being bonded to aliphatic backbone carbon atoms of the epoxy resin by carbon-to-carbon bonds, andP P (ii) an extender resin;PPb. an aqueous vehicle, and PPc. an ionizing agent;PPthe ionization present from said combined components being sufficient to establish the components as a dispersion in the aqueous vehicle, and then addition polymerizing a quantity of addition polymerizable monomer, under addition polymerizing conditions, in said aqueous dispersion, the aqueous dispersion serving as a vehicle therefor.PPIn another aspect of the invention, a grafting base is produced by advancing an aromatic epoxy resin in the presence of at least one extender resin and a sufficient amount of an organic solvent to render the initial mixture and grafting base product fluent.