least one-half-the initial acid value of the mixture of phosphates, wherein R is hydrogen or methyl and R is a lower alkylene or halogenated lower alkylene group, B is a polymerizable ethylenically unsaturated monomer and C is an unsaturated polyester obtained by reacting the components of a mixture containing propylene glycol and maleic anhydride, to obtain a water-in-oil emulsion, adding a poly