ES350828A1 - Process for interpolymerzing methyl methacrylate with ehtylene copolymers - Google Patents

Abstract

A process comprises interpolymerizing (A) from 75% to 5% by weight of a copolymer of (1) ethylene, and (2) at least one comonomer selected from vinyl acetate, ethyl acrylate, acrylic acid, methacrylic acid, methyl acrylate and stearyl methacrylate, said copolymer containing from 50 to 95% by weight of ethylene, with (B) from 25% to 95% of a monomer component consisting of (1) at least 50% by weight of methyl methacrylate, (2) 0% to 50% of vinyl acetate or ethyl acrylate or mixtures thereof, and (3) 0% to 20% of a copolymer - izable monomer, the interpolymerization being carried out in the presence of a free-radical catalyst at a temperature of 10 to 150 C. and in the absence of water. In Examples 1 to 11, an ethylene-vinyl acetate copolymer is crosslinked with dicumyl peroxide prior to being dispersed in a toluene/graft monomer mixture and grafted with methyl methacrylate, alone or together with vinyl acetate. Graft polymers are prepared similarly in Examples 13 to 20, except that the ethylene copolymer substrate is not cross-linked and the graft monomers comprise a mixture of methyl methacrylate with ethyl acrylate, or (a) the substrate is a crosslinked ethylene-stearyl methacrylate copolymer and the graft monomers are methyl methacrylate, vinyl acetate and acrylic acid (b) the substrate is a cross-linked ethylene-methyl acrylate copolymer and the graft monomers are methyl methacrylate, ethyl acrylate and vinyl acetate (c) the substrate is a cross-linked ethylene-acrylic acid copolymer and the graft monomers are methyl methacrylate, vinyl acetate and acrylonitrile or (d) the substrate is a cross-linked ethylene-methacrylic acid copolymer and the graft monomers are methyl methacrylate, ethyl acrylate and stearyl methacrylate. In Examples 21 and 22 a solution of ethylene-vinyl acetate copolymer in methyl methacrylate and ethyl acrylate is prepolymerized and then cast into a glass cell and heated to form a cast sheet. A U.V. stabilizer selected from p-methoxybenzylidene dimethyl malonate, 2 - hydroxy - 4 - methoxybenzophenone and 2 - (21 - hydroxy - 51 - methylphenyl) benzotriazole and/or an antioxidant selected from butylated and styrenated cresols, 2,5 - di - (t - butyl) - 4 - methylphenol, 2,21- methylenebis - (4 - ethyl - 6 - t - butyl) phenol and tris-(nonylphenyl) phosphite are added to the graft polymers or prepolymers.