0-10,000 determined by gel permeation chromatography; (b) 5-18% by weight of an epoxy resin of the formula ##STR7## where n is a positive integer and R is an aromatic radical; (c) 0.1-3% by weight of triglycidyl isocyanurate; (d) 30-55% by weight of calcium carbonate pigment and (e) 0.9-10% by weight of finely divided polypropylene particles. 2.