Method of preparing resin

A method of preparing a resin composition and having a softening point in the range of about 100.degree. C. to about 300.degree. C., which comprises free radical polymerizing, in an aqueous medium having a pH in the range of about 2 to about 7 and in the presence of a free radical initiator and organic mercaptan chain transfer agent, a monomer mixture, based on 100 weight percent of monomers, in a dispersion by mixing with or in water (A) about 0.25 to about 2 weight percent of at least one water soluble, polymerizable surfactant in the form of a bifunctional monomer in acid form or neutralized salt thereof, said monomer composed of (i) a first, hydrophilic functional component selected from at least one reactive acid radical or neutralized metal salt thereof selected from at least one of sulfate, sulfonate, carboxylate or phosphate radicals where said metal salts thereof are selected from at least one of sodium, potassium, ammonium or organic amine salts and (ii) a second hydrophobic functional component comprised of at least one of (a) alkenyl aromatic radical selected from at least one of styrene, .alpha.-methylstyrene and vinyl toluene or (b) selected from at least one of ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, tridecene, tetradecene, pentadecene and hexadecene of (c) an n-alkylol amide of an alpha-beta-olefinically unsaturated carboxylic acid having 4-10 carbon atoms, (B) about 60 to about 95 weight percent of at least one hard segment hydrophobic enhancing monomer selected from styrene, .alpha.-methylstyrene, acrylonitrile, methacrylonitrile, vinyl toluene, methyl methacrylate, vinyl chloride and vinylidene chloride, (C) about 0 to about 35 weight percent of at least one soft segment hydrophobic enhancing monomer selected from at least one acrylate selected from methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, or at least one vinyl ether selected from methyl, ethyl, butyl, octyl, decyl, dodecyl and cetyl vinyl ether and/or at least one diene selected from 1,3-butadiene, isoprene and 2,3-dimethyl butadiene, provided that said dienes of monomer part (C) and said monomer part (B) vinyl chloride and vinylidene chloride are not mixed together and copolymerized, and (D) about 0.25 to 5.0 weight percent of at least one hydrophilic enhancing organic acid selected from acrylic, methacrylic, fumaric, itaconic and maleic acid;

• and where in said aqueous polymerization medium, if additional emulsifier(s) is used, it is used in an amount up to a maximum of about 5 weight percent of said bifunctional monomer surfactant used.