A method for improving the properties of butyl rubber - vulcanizates

摘要

A filler for butyl rubber consists of precipitated hydrated silica, or precipitated hydrated calcium silicate or kaolin, having a particle size not greater than 10 microns and having been reacted with an unsaturated organohalosilane selected from cycloalkarylhalosilanes and cycloalkenylalkylhalosilanes. Specified organohalosilanes are cyclohexanyltrichlorosilane, beta-(3-cyclohexanyl)-ethyltrichlorosilane, 6-methyl-3-cyclohexenyltrichlorosilane and 3-methyl-3-cyclohexenyltrichlorosilane. The filler may be reacted with the organohalosilane by slurrying the filler in a low-boiling hydrocarbon, e.g. petroleum ether, adding the silane and refluxing, or by passing air saturated with the silane through a tube containing the filler or the filler and silane may be added separately to butyl rubber during compounding, together with the normal vulcanising agents and vulcanised. U.S.A. Specification 2,535,036 is referred to.ALSO:A filler for butyl rubber consists of precipitated hydrated silica, or precipitated hydrated calcium silicate or kaolin, having a particle size not greater than 10 microns and having been reacted with an unsaturated organohalosililane selected from cycloalkenylhalosilanes and cycloalkenylalhylhalosilanes. Specified organohalosilanes are cyclohexenyltrichlorosilane, 6-methyl-3-cyclohexenyl-trichlorosilane, and 3-methyl-3-cyclohexenyl trichlorosilane. The filler may be reacted with the organohalosilane by slurrying the filler in a long boiling hydrocarbon, e.g. petroleum ether adding the silane and refluxing or by passing air saturated with the silane through a tube containing the filler, or the filler and silane may be added to butyl rubber during compounding and reacted in situ. U.S.A. Specification 2,535,036 is referred to.