GB647311A - Improvements in or relating to surface-treated silicon dioxide - Google Patents

Abstract

A vulcanizable composition comprises a vulcanizable synthetic rubber, a vulcanizing agent therefor and combustion silica containing adsorbed basic material (see Group III). Compositions exemplified are (1) butadiene-styrene copolymer (75 : 25), zinc oxide, pine tar resin, sulphur and combustion silica which has been treated with diphenylguanidine, and (2) butadiene-styrene co-polymer (60 : 40), zinc oxide, stearic acid, sulphur and combustion silica which has been treated with a mixture of triethanolamine and triethyl - trimethylenetriamine.ALSO:Surface treated silica, e.g. of average particle diameter of 5-200 millimicrons, comprises the product of combustion of a silicon-bearing material and a basic material disposed on the surface thereof, the proportion of base per mole of SiO2 being, e.g. 0.1 to 15 milliequivalents. The silica may be made either (a) from silicon, ferrosilicon, silicon - nitride, - monosulphide, -tetra-acetate or -disulphide either by vaporization and rapid oxidation thereof in a furnace or electric arc or by spraying the powdered materials into an oxygen-gas flame, a preferred method being to mix sand or ferrosilicon with ground coal or powdered carbon fuels and burn the mixture in air in a furnace, or (b) from ethyl silicate, silicon tetrachloride, trisilicane amine, chloro-, bromo-, dibromo-, dichloro-, tribromo-, trichloro-, trifluoro-, triiodo-, di-, tri-, tetra-, dimethyl-, ethoxytriethyl-, methyl-, tetraethyl-, tetramethyl-, trichlorophenyl-, triethyl-, chloromethyl-, and dichloromethyl silicanes, silicane ether, silicon tetrabromide, silicon bromotrichloride, silicondibromodichloride, silicontribromochloride, siliconchlorohydrosulphide, silicontetrafluoride, siliconiodotrichloride, siliconoxychloride, and disiloxane, by the vaporization and burning thereof, with or without admixture of a combustible gas. Basic materials specified are: sodium-, potassium- and ammonium hydroxides, triethanolamine, tetramethylammonium hydroxide, and diallyl-, diamyl-, dibenzyl-, dibutyl-, dicyclohexyl-, ethyl-, diethyl-, tertiarybutyl-, alphaphenylethyl-, methyl-, triphenyl-, tripropyl-, isohexyl-, secondary butyl-, diphenyl-, alphanaphthyl-, betanaphthyl-, phenyl - beta - naphthyl -, dodecyl -, dilauryl-, octyl-, undecyl- and diocta-decyl amines, ethylene diamine, 1 - amino - 2 - phenylethane, hexamethylene tetramine, diphenylguanidine, di-ortho-tolyl guanidine, trimethylenediamine and aniline. In one example a mixture of triethanolamine and triethyltrimethylenetriamine is used.ALSO:A vulcanizable composition comprises a vulcanizable rubber, a vulcanizing agent therefor, and combustion silica containing adsorbed basic material (see Group III). Compositions exemplified are: (1) natural rubber, zinc oxide, pine tar, sulphur, 2-mercaptobenzothiazole and surface-treated combustion silica as reinforcing material; (2) butadiene-styrene copolymer (75 : 25), zinc oxide, pine tar resin, sulphur and combustion silica which has been treated with diphenylguanidine; and (3) butadiene-styrene copolymer (60 : 40), zinc oxide, stearic acid, sulphur and combustion silica which has been treated with a mixture of triethanolamine and triethyl trimethylene triamine.