Acrylic resin-acrylic microgel compositions

A method of making an acrylic microgel resin for use in paint systems to provide coatings of improved pigment orientation and sag resistance which comprises preparing an aqueous microgel emulsion by the emulsion polymerization in water of a mixture of ethylenically unsaturated monomers, at least one of said monomers being an acrylic or methacrylic acid, or an --OH substituted alkyl ester thereof, and containing a --COOH or --OH group, and at least another of said monomers being selected from an alkyl ester of an acrylic or methacrylic acid, styrene and alpha-methyl styrene, and being free from --COOH and --OH groups, and a multifunctional crosslinking agent present in an amount of 5-70 percent by weight of the total weight of said ethylenically unsaturated monomers and crosslinking agent, removing water from the emulsion by coagulation and/or azeotropic distillation with an organic solvent in which the microgel is insoluble and which forms an azeotrope with water, and incorporating the microgel into an acrylic resin prepared by polymerizing two or more ethylenically unsaturated monomers in an organic solvent solution wherein at least one of said monomers is an --OH substituted alkyl ester of an acrylic or methacrylic acid and optionally a monomer containing a --COOH group selected from an acrylic or methacrylic acid, and another of said monomers being selected from an alkyl ester of an acrylic or methacrylic acid, styrene and alpha-methyl styrene, and being free from --COOH and --OH groups to provide said acrylic microgel resin wherein the amount of microgel solids is in the range of 5 to 15 percent by weight of the total resin solids.