GB802195A - Copolymer-oil modified butyl rubber - Google Patents

Abstract

A vulcanizable composition comprising 50 to 99 parts by weight of a synthetic butyl rubber, 2 to 40 parts by weight of an oily copolymer of a C4-C10 conjugated diolefine and a vinyl aromatic compound, or an oily homopolymer of a C4-C10 conjugated diolefine, and 0.1 to 10 parts of a nitrogen-containing organic compound containing at least one =NH group, and optionally up to 75 parts of carbon black or clay, and up to 50 parts of zinc oxide. Aldehyde amines or amides, polyalkylated amines or amides, guanidines, sulphur-containing guanidines, amines and amides, and sulphonamides particularly reaction products of aniline and butyraldehyde, p-toluidine and formaldehyde, triethyl-trimethylene triamine, hexamethylene tetramine, diphenyl and triphenyl guanidine, diortho tolyl guanidine, 2-mercapto - imidazoline, t - butyl - 2 - benzothiazole and N-cyclohexyl-2-benzothiazole sulphenamides may be used. The butyl rubber, a copolymer of a major proportion of a relatively low molecular weight iso-olefine such as isobutylene and a minor proportion of a multiolefine of about 4 to 14 carbon atoms such as isoprene, butadiene, 2-methylpentadiene, dimethyl butadiene, myrcene, piperylene and allocimene may include a portion of butyl reclaim and/or partially polymerized butyl rubber, other synthetic rubbers and natural rubbers. The polymer or copolymer oils are preferably prepared from butadiene, which may be substituted in part by isoprene, 2,3-methylbutadiene-1,3, piperylene or 2-methyl pentadiene-1,3, and styrene or methyl, dimethyl, ethyl and diethyl styrenes with a sodium, sodium hydride or potassium catalyst. The compositions may include titanium and magnesium oxides, calcium carbonate, ferric hydroxide, chrome yellow, Prussian blue, ultramarine blue, and phthalocyanine, antioxidants, e.g. n-lauroyl p-amino phenol, phenyl b -naphthylamine, bis - (2 - hydroxy - 3 - t - butyl - 5 - methyl phenyl) methane and heptylated diphenylamine and stearic acid, and may be cured at between 250 DEG and 450 DEG F. with sulphur or sulphur containing agent. The composition may be used as side walls or inner liners in tubeless tyres.