Halobutyl rubbers are used in inner liners and sidewalls for tyres, heat resistant inner tubes, tank linings, pharmaceuticals, automobile mounts, and an increasing number of other applications. Annual world con-sumption doubled between 1974 and 1979, and is expected to exceed 100 x 10^3 t in 1980.1.3. Manufacturing FacilitiesThere are now ten facilities, worldwide, producing butyl rubbers (Table 1) with an aggregate nameplate capacity exceeding 500 x 10^3 t. Esso, Exxon and the two Polysar plants include halobutyl rubbers in their product lines Polysar Ltd is the only producer of crosslinked butyl terpolymers.1.4. Types and Grades Available.The International Institute of Synthetic Rubber Producers (IISRP) lists 35 grades of standard butyl rubbers which together with four other that are commercially available, are distributed in the unsaturation and viscosity ranges as indicated in Table 2. Staining and non-staining grades are available at most unsaturation and viscosity levels. Two grades, designed primarily for use in chewing gum and other food contact applications, do not contain a stabiliser at all.The IISRP listings also include two crosslinked, one brominated and two chlorinated grades of butyl rubber, but three additional grades of halobutyl rubber have become commercially available since the listings were compiled.
đang được dịch, vui lòng đợi..
