GB804208A - Method for making latex foam rubber - Google Patents

Abstract

<PICT:0804208/IV (a)/1> A latex foam rubber is made by forming an acid-coagulable fluid latex foam, coagulating the foam by diffusing a coagulating acid gas at below room temperature through the foam at atmospheric pressure, and vulcanizing the coagulated foam. Specified rubbers are natural rubber, polymers of butadiene, 1,4- or 2,3-dimethyl butadiene, and their copolymers with each other or with styrene, methyl or ethyl acrylate or methacrylate, acrylonitrile and isobutylene, as well as polychloroprene. Specified coagulants are gaseous carbon dioxide, sulphur dioxide, hydrogen chloride or sulphide, acid-forming nitrogen oxides, a mixture of carbon dioxide and nitrogen, and a mixture of air with carbon dioxide or sulphur dioxide. It is preferred that the gaseous coagulating fluid is at - 10 DEG to - 20 DEG C., the latex foam is chilled to 0 DEG to 10 DEG C., from 10 to 100 per cent by volume of gas is diffused through the foam and the latex foam is formed into a sheet before the coagulating. Referring to the drawing the latex is foamed in apparatus 10, cooled by coils 11 and discharged to conveyer belt 13 which has been chilled by passing through refrigerator 14. The latex is coagulated in chamber 17, charged through pipe 18 with coagulating acid gas, passed through vulcanizer 19, washed under sprinkler 20 and dried in drier 21.