WATER-DILUTIVE BINDER UNDERGOING OXIDATIVE CROSSLINKING,AND ITS MANUFACTURE AND APPLICATION

Oxidatively cross-linkable, water dilutable binders suitable for lacquers, coating compositions and sealing compounds are modified co-polymers of olefinically unsaturated compounds, having a molecular weight of 6000 to 160,000 and having for each 100 grams of solids content, a total of from 60 to 250 milliequivalents of chemically incorporated carboxyl groups, of which from 10 to 100% are neutralized thereby rendering the product dilutable in water and from 15 to 50% by weight of chemically incorporated moieties corresponding to the formula -O-R wherein R represents an olefinically monounsaturated or polyunsaturated aliphatic hydrocarbon having a molecular weight above 166 and containing from 12 to 22 carbon atoms, are prepared by: (a) preparing a co-polymer having a molecular weight from 5000 to 80,000, determined by gel permeation chromatography, and having intramolecular carboxylic acid anhydride units corresponding to the formula and an anhydride equivalent weight of from 240 to 1960 by a radically initiated co-polymerization of olefinically unsaturated dicarboxylic acid anhydrides with other olefinically unsaturated monomers, (b) reacting at least 50% of the acid anhydride units present in the co-polymer from (a) with an unsaturated monohydric alcohol corresponding to the formula R-OH with anhydride ring opening ester formation, and (c) converting the free carboxyl groups in the reaction product of (b) to an extent of 10 to 100% into carboxylate groups by neutralization of the carboxys with a base.