The aqueous primer - composition

PURPOSE:To provide an aqueous primer compsn. being a stable emulsion, with excellent appearance and water resistance and giving a primer coating film with good adhesion to the substrate. CONSTITUTION:This primer compsn. is prepd. by neutralizing a modified chlorinated polypropylene resin prepd. by graft-polymerizing a chlorinated polypropylene resin, an unsatd. carboxylic acid and at least one emulsifier selected from a polymerizable nonionic emulsifier and an ammonium salt type polymerizable anionic emusifier, with an amine and emulsifying it into water.