ercent of at least one copolymerizable vinyl monomer.Examples of the copolymerizable monomers from which the copolymers useful in the present invention are formed include vinyl esters such as vinyl acetate, vinyl propionate, vinyl maleate, vinyl fumurate, and the like, acrylic and methacrylicacids, acrylic and methacrylic acid esters such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl