Binders for use in cathodic electrodeposition coatings, process for their preparation and cathodic electrodeposition coating compositions containing same

摘要

Novel alkaline polymeric binders, preferably amino epoxy binders, for use in cathodic electrodeposition coatings have a number average molecular mass of 1000 to 3000, an amine value of 150 to 250 mg KOH/g binder and 50 to 230 milliequivalents/100 g binder of beta-hydroxyalkyl urethane groups of the formula HOC_nH_2nOC(O)NH- where n = 2 to 3, as well as processes for making such binders; aqueous compositions, particularly cathodic electrodeposition compositions containing such binders (which provide improved throwing power); and process of using such compositions, particularly on automotive bodies and parts thereof, are disclosed.