AQUEOUS BRANCHED POLYMER DISPERSANT FOR HYDROPHOBIC MATERIALS

A waterbased dispersion useful for forming aqueous coating compositions containing dispersed hydrophobic material, an aqueous carrier and a branched polymer dispersant (binder); the branched polymer has a weight average molecular weight of about 5,000 - 100,000 and contains 20-80 % by weight of a hydrophilic backbone and correspondingly 80-20 % by weight of macromonomer side chains; wherein the backbone is of polymerized ethylenically unsaturated monomers and 2-30 % by weight, based on the weight of the backbone of polymerized ethylenically unsaturated monomers having an acid-functional group; and wherein at least 10 % of the acid-functional groups are neutralized with an amine or an inorganic base and is hydrophilic in comparison to the side chains; and the side chains are of macromonomers of polymerized ethylenically unsaturated monomers that are polymerized into the backbone via an ethylenically unsaturated group and the macromonomers have a weight average molecular weight of about 1,000-30,000 and wherein the weight ratio of hydrophobic material to binder is about 1/100 - 200/100.