the need for a separate source of active hydrogen additional external active hydrogen components may optionally be present in the copolymer binder composition and may serve as a plasticizer as well as a cross linker the hydroxyl or amine monomer makes up from 0 to 75 mole percent and preferably 10 to 20 mole percent of the copolymer examples of hydroxyl monomers useful in forming the copolymer of the invention include but are not limited to hydroxy propyl meth acrylate hydroxy ethyl meth acrylate hydroxy butyl meth acrylate and methacrylate esters of poly ethylene propylene butylene glycol in addition one could use the acrylamide or methacrylamide version of these monomers also monomers like vinyl acetate that can be hydrolyzed to vinyl alcohol after polymerization may be used preferred monomers are hydroxypropyl acrylate and methacrylate examples of amine functional monomers useful in the present invention include n n dialkylaminoalkyl meth acrylate n n dialkylaminoalkyl meth acrylamide namely dimethylaminopropyl methacrylate dimethylaminoethyl methacrylate tert butylaminoethyl methacrylate and dimethylaminopropyl methacrylamide in addition monomers like vinyl formamide and vinylacetamide that can be hydrolyzed to vinyl amine after polymerization may also be used furthermore aromatic amine monomers such as vinyl pyridine may also be used the copolymer could contain a mixture of both hydroxyl and amine functional monomers it was found that copolymers containing lower levels of these functional monomers were more flexible than copolymers containing higher levels of these functional monomers while not being bound to any particular theory it is believed this may be related to the lower tg copolymers that are formed amide functional monomers could also be used to form the copolymer if.