GB506565A - Improvements in the treatment of rubber and similar oxidizable materials - Google Patents

Abstract

506,565. Preserving rubber, oils, etc.; antioxidant UNITED STATES RUBBER PRODUCTS, Inc. Sept. 6, 1938, No. 26008. Convention date, Sept. 11, 1937. [Class 70] [Also in Groups III and IV] Rubber and the like and other oxidizable materials, e.g. unsaturated fatty oils, essential oils, petroleum oils and their derivatives such as gasolines, soaps, aldehydes and synthetic resins, are preserved by incorporating a small proportion, e.g. À1 to 5 per cent, of an N- carbamyl derivative of an amino-diarylamine having the general formula where R1 is an aryl group, R2 is an arylene group, X is oxygen, sulphur or an imide radical and R is hydrogen or a hydrocarbon group. The compounds may be made for example by the reaction of a carbamyl halide on a primary-amino-substituted diarylamine. In examples: (1) 21 gms. of p-amino-diphenylamine are heated for 1¢ hours with an excess over the molecular equivalent of urea at 150‹ C. with evolution of ammonia. The molten mass is poured in water while agitating and the precipitate is washed with hot water and dried. The product is believed to have the formula, and may be called p-anilino-phenyl urea; (2) 23 grams-of p-amino-phenyl p-tolylamine are dissolved in 200 cc. of benzol, 17 gms. of phenyl mustard oil are added. On standing a gray powder separates which may be washed with benzol and dried. It is believed to have the formula and may be called p-(p-tolylamino) diphenyl thiourea; (3) “ mole of p-amino-phenylptolyl amine is refluxed for 72 hours with an excess over “ mole of carbon bisulphide in 300 cc. of alcohol containing a pinch of sulphur and 2 gms. of potassium hydroxide. The product is believed to have the formula and may be called p, p<1>-di(p-tolylamino) diphenyl thiourea. Lists of primary-secondary aromatic amines, carbamyl derivatives of which may be used, and of carbamyl groups, are given in the Specification. The compounds may be used in conjunction with other types of antioxidants, e.g. ketone-diarylamine reaction products.