Process for producing a resin coating

A resin coating resistant to low-temperature flexing, heat and impact is prepared by a process comprising graft polymerizing methacrylic acids or esters on cellulose acetate in solution or suspension. The resin improves the weathering resistance, mechanical strength and adhesive property of the low viscosity cellulose acetate butylate by grafting acrylates or methylacrylic esters on the cellulose acetate. The cellulose acetate butylate having 5 to 30% acetyl radicals and 15 to 55% butyl radicals may be any degree of esterification, and is in particulate, fiber, film or pellet form. The acrylic acids or methacrylic esters may be alkyl esters having from 1 to 4 carbon atoms of methyl acrylate, ethyl acrylate, butyl acrylate or butyl methacrylate. The graft polymerization can be carried out by irradiating with ionizing radiations, utilizing radical polymerization initiators, namely, secondary cesium salt or Ag+S2O8--systems, or pretreatment of the butylate in the presence of oxygen or peroxide. The degree of graft polymerization is 5 to 100%, preferably 50 to 300%. In examples, 10 parts of cellulose acetate butylate, 31 parts of methyl acetate, 0.2 parts of benzoil peroxide and 0.05 parts of dodecyl mercaptane are suspended in 150 parts of water, then polymerized at 600C for 2 hours to form a spheroidal resin. The spheroidal resin is pressed while heating to form a sheet of breakdown strength 0.91 kg/mm2, elongation 575% and a 100% modulus 0.5 kg/mm2. (Iwakiri, K.)