GB711236A - Improvements in or relating to process of vulcanizing rubber and the vulcanized rubber resulting from the said process - Google Patents

Abstract

Synthetic rubbers are vulcanized by heating with a reinforcing type furnace black and an N, N1- thio-bis-secondary amine in which not more than two sulphur atoms connect the nitrogen atoms, the secondary amine radicals being six membered heterocyclic amine groups, alkyl groups, substituted alkyl groups, alicyclic groups or mixtures thereof. A large number of such amines is specified and of these the following are used in examples:-N, N1 -dithiobis-morpholine, N,N1 -dithiobis-beta-isopropylaminopropionitrile, N,N1 -dithio-bis-diisopropylamine, N,N1- dithio-bis-piperidine, N,N1 - dithio-bis-pipecoline, N,N1 -dithio-bis-N-n-butyl tetra hydrofurfurylamine, N,N1 -dithio-bis-diethylamine, N,N1 -dithio-bis-dioctylamine, N,N1 -dithio-bis-beta-ethylamino-propionitrile, N,N1 -dithio-bis-beta-n-butylamino propionitrile, N,N1-dithio-bis-cyclohexylamino acetonitrile, N,N1-dithio-bis-n-butylamino acetonitrile, N,N1 -dithio-bis-betaisopropylamino-propionitrile, N,N1 dithiobis - N - cyclohexyltetrahydrofurfuralde - hyde, N,N1 -dithio-bis-di-isopropylamine. Specified synthetic rubbers are polymerized isoprene and butadiene, and copolymers of butadiene with styrene or acrylonitrile. Free sulphur is preferably omitted but may be added in small quantity. Known accelerators such as N-cyclohexyl-2-benzothiazole and dithio-bis-benzothiazole may also be incorporated. A base formula to which the accelerators of the invention may be added comprises GR-S rubber 100 parts, Philblack 0 40, Philblack A 10, zinc oxide 4, stearic acid 2, and hydrocarbon softener 10.ALSO:Natural and synthetic rubbers are vulcanized by heating with a reinforcing type furnace black and a N,N1-thio-bis-secondary amine as the essential vulcanizing agent in which not more than two sulphur atoms connect the nitrogen atoms, the secondary amine radicals being six membered heterocyclic amine groups, alkyl groups, substituted alkyl groups, alicyclic groups and mixtures thereof. A large number of such amines is specified and of these the following are used in examples:-N,N1-dithio-bis-morpho-line, N,N1-dithio-bis-beta-isopropylaminopropionitrile, N,N1-dithio-bis-diisopropylamine, N,N1-dithio-bis-piperidine, N,N1-dithio-bis-pipecoline, N,N1-dithio-bis-N-n-butyl tetra hydro-furfuryl-amine. N,N1-dithio-bis-diethylamine, N,N1-dithio-bis-dioctylamine, N,N1 - dithio - bis - beta - ethylamino-propionitrile, N,N1-dithio-bis-beta-n-butylamino propionitrile, N,N1-dithio-bis-cyclohexylamino acetonitrile, N,N1-dithio-bis-n-butylamino acetonitrile, N,N1-dithio-bis-beta-isopropylamino-propionitrile, N,N1 - dithio - bis - N - cyclohexyltetrahydrofurfuraldehyde, N,N1-dithio-bis - di - isopropylamine. Specified synthetic rubbers which may be used are polymerized isoprene and butadiene, and copolymers of butadiene with styrene or acrylonitrile. Free sulphur is preferably omitted but may be added in small quantity. Known accelerators such as N-cyclohexyl-2-benzothiazole and dithio-bis-benzothiazole may also be incorporated. A base formula to which the accelerators of the invention may be added comprises smoked sheets zinc oxide, stearic acid, Philblack O, hydrocarbon softener, p. aminodiphenyl-acetone reaction product and N-cyclohexyl-2-benzothiazole sulphonamide.