GB853926A - Curing of rubber latex and the productionof articles therefrom - Google Patents

Abstract

Natural or synthetic rubber latex is cured by subjecting it in the form of an aqueous dispersion to irradiation by high energy electrons, X-rays, alpha, beta, or gamma rays, protons, deuterons, or neutrons. The latex may be of Hevea brasiliensis, kok-saghyz, gutta-percha, bata, a polymer of a diene hydrocarbon, e.g.polybutadiene, or a copolymer of a diene with another compound, e.g. butadiene-acrylonitrile or butadiene-styrene copolymer, or a polymer of a substituted conjugated diene containing the group CH2 : C.Cl, e.g. polychloroprene. The prefered sources of radiation are linear accelerators and radioactive cobalt, and the preferred dosage of radiation is 3 X 106 to 1 X 108 Roentgens. The cured latex may be used for producing rubber articles without the addition of sulphur or other curing agent. Articles may be formed by dipping with or without the use of coagulant. Foam rubber may be prepared by whipping the latex to a froth after addition of a soap and then gelling the froth, and rubber threads may be prepared by extruding the cured latex through jets into a coagulant. In all cases the product is dried either at room temperature or at about 40 DEG C. Examples are described in which (1) natural rubber latex is exposed to gamma radiation from radioactive cobalt, (2) natural rubber latex is exposed to a beam of high energy electrons from a linear accelerator, and (3) a latex produced by the emulsion copolymerization of butadiene and styrene is exposed to gamma radiation from radioactive cobalt.