GB592010A - Improvements in vulcanization of rubber - Google Patents

Abstract

Synthetic rubbers such as copolymers of butadiene with styrene or with acrylonitrile are vulcanized with the aid of an accelerator having the general formula <FORM:0592010/IV/1> where A is a branched chain alkyl radical. The preferred compound is N-isopropyl benzothiazyl sulphenamide which may be prepared by condensing mercaptobenzthiazole with isopropylamine in the presence of an oxidizing agent such as hydrogen peroxide, the crude product being recrystallized from ligroin. Other accelerators such as mercaptothiazoles, mercaptoarylthiazoles, mercaptothiazolines, diarylguanidines and their salts, and dithiocarbamates, and also sulphur, fillers, pigments, softeners and anti-oxidants may be added. Specification 517,451 and U.S.A. Specification 2,339,552 are referred to.ALSO:Rubber and synthetic rubbers such as copolymers of butadiene with styrene or with acrylonitrile are vulcanized with aid of an accelerator having the general formula <FORM:0592010/V/1> where A is a branched chain alkyl radical. The preferred compound is N-isopropyl benzothiazyl sulphenamide which can be prepared from mercaptobenzthiazole and isopropylamine by the method of Group IV. The efficiency as an accelerator of this compound is compared with that of N-n-propylbenzothiazyl sulphenamide prepared according to the method of U.S.A. Specification 2,339,552 when used in master batches containing smoked sheet rubber, carbon black, zinc oxide, zinc laurate, pine tar, sulphur and acetone-diphenylamine condensate. Other accelerators such as mercaptothiazoles, mercaptoaryl thiazoles, mercapto thiazolines, diarylguanidines and their salts, and dithiocarbamates, and also fillers, pigments, softeners, and antioxidants may be added. Specification 517,451 also is referred to.