Controlled film build epoxy coatings applied by cathodic electrodeposition.

摘要

A blend of (I) an advanced epoxy-based cationic resin prepared by reactng in the presence of a suitable catalyst (A) a composition comprising (1) from 20 to 100 weight percent of a diglycidyl ether of a polyol and (2) from zero to 80 weight percent of a diglycidyl ether of a dihydric phenol with (B) at least one dihydric phenol and optionally, (C) a monofunctional capping agent; wherein components (A) and (B) are employed in such amounts that the resultant advanced epoxy resin has an average epoxide equivalent weight of from 350 to 10,000 whereby there is formed an advanced epoxy resin having terminal oxirane groups and subsequently converting at least some of the oxirane groups to cationic groups; and (II) a different epoxy-based cationic cathodic electrodeposition resin. Such resin blends can be utilized in cathodic electrodeposition coating system. These resin blends provide coating compositions with lower viscosity and produces electrodeposition coatings of higher film build than compositions which do not contain component I.