Improvements in rubber compositions

摘要

1,4 - Diamino - 2,3,5 - trimethyl - 6 - ethylbenzene is prepared by acetylating pseudocumene with acetic anhydride, reducing the ketone formed to 2,3,5-trimethyl-6-ethylbenzene, which is then nitrated and reduced to the diamine.ALSO:Vulcanized synthetic rubber compositions comprise 0.5 to 10 per cent of an ozone inhibitor of the formula: where R is hydrogen or an alkyl group having 1 to 4 carbon atoms, at least one R being an alkyl group, which is incorporated before vulcanization. Specified rubbers are butadiene-1,3, isoprene, piperylene, chlorobutadiene and cyanobutadiene, and copolymers of these with styrene, chlorostyrene, isobutylene, acrylonitrile, methacrylonitrile, acrylic and methacrylic acids, alkyl acrylates and methacrylates, vinylidene chloride and vinyl pyridine. Specified inhibitors are 1,4 - diamino - 2 - methylbenzene, 1,4 - diamino - 2 - ethylbenzene, 1,4 - diamino - 2 - propylbenzene, 1,4 - diamino - 2 - butylbenzene, 1,4 - diamino - 2,5 - dimethylbenzene, 1,4 - diamino - 2,5 - diethylbenzene, 1,4 - diamino-2,5 - dipropylbenzene, 1,4 - diamino - 2-methyl - 5 - ethylbenzene, 1,4 - diamino - 2-methyl - 5 - propylbenzene, 1,4 - diamino-2,3,5 - trimethylbenzene, 1,4 - diamino - 2,3,5-tributylbenzene, 1,4 - diamino - 2,3,5,6 - tetramethylbenzene, 1,4 - diamino - 2,3,5,6 - tetraethylbenzene, 1,4 - diamino - 2,3,5,6 - tetrapropylbenzene, 1,4 - diamino - 2,3,5,6 - tetrabutylbenzene, 1,4 - diamino - 2,3,5 - trimethyl-6 - ethylbenzene, 1,4 - diamino - 2,3,5 - trimethyl - 6 - propylbenzene, 1,4 - diamino - 2,5-dimethyl - 3,6 - diethylbenzene and 1,4 - diamino - 2,5 - dimethyl - 3,6 - dipropylbenzene. The compositions may contain waxes, e.g. carnauba, ceresin, montan and paraffin waxes. Conventional fillers, e.g. carbon black and zinc oxide, pigments, e.g. titanium dioxide and Ultramarine Blue, and vulcanizing ingredients, e.g. sulphur, stearic acid, benzothiazyl disulphide, reaction products of heptaldehyde and aniline, phenyl-beta-naphthylamine and sym. di - beta - naphthyl - para - phenylenediamine may be added.ALSO:Vulcanized rubber compositions have incorporated therein prior to vulcanization 0,5 to 10 per cent by weight of the rubber of an ozone inhibitor of the form: where at least one R is an alkyl group having 1 to 4 carbon atoms, any remaining R or R's being hydrogen. Specified inhibitors are 1,4-diamino-2-methylbenzene, 1,4-diamino-2-ethylbenzene, 1,4-diamino-2-propylbenzene, 1,4-diamino-2-butylbenzene, 1,4-diamino-2,5-dimethylbenzene, 1,4-diamino-2,5-diethylbenzene, 1,4-diamino-2,5-dipropylbenzene, 1,4-diamino-2-methyl-5-ethylbenzene, 1,4-diamino-2-methyl -5-propylbenzene, 1,4-diamino-2,3,5-trimethylbenzene, 1,4-diamino-2,3,5-tributylbenzene, 1,4 -diamino-2,3,5,6-tetramethylbenzene, 1,4-diamino-2,3,5,6-tetraethylbenzene, 1,4-diamino2,3,5,6-tetrapropylbenzene, 1,4-diamino-2,3,5,6 -tetrabutylbenzene, 1,4-diamino-2,3,5-trimethyl-6-ethylbenzene, 1,4-diamino-2,3,5-trimethyl-6-propylbenzene, 1,4-diamino-2,5-dimethyl-3,6-diethylbenzene and 1,4-diamino-2,5 -dimethyl-3,6-dipropylbenzene. The compositions may contain waxes, e.g. carnauba, ceresin, montan and paraffin waxes.