| abstract |
A composition comprising a copolymer of from 20 to 60 parts of at least one member selected from the class consisting of acrylic and methacrylic acids, from 20 to 70 parts of one member selected from the class of lower alkyl acrylates and lower alkyl methacrylates, and from 5 to 20 parts of a plasticizing monomer, in which at least some of the acid groups have been neutralized by multivalent cations, where a chemical, exclusive of water and plasticizer, releasable from a film of the referenced copolymer, is formed by casting and drying an aqueous solution of the copolymer containing the chemical. |