Patent GB-837159-A (GB)
Title: Vulcanisation accelerators
IPC: C07D295/26
Filed: 1958-01-10
Abstract: The invention comprises compounds of the general formula <FORM:0837159/IV (b)/1> where R1 and R2, which may be the same or different, are hydrogen, saturated or unsaturated hydrocarbon radicals, cycloalkyl, alkylaryl, or aryl radicals, or R1 and R2 together with the nitrogen atom may form a heterocyclic ring system, which may also contain other hetero atoms.  Specified groups for R1 and R2 are hydrogen, ethyl, iso-propyl, allyl, t-butyl, cyclohexyl, methyl, butyl, phenyl, benzyl, 2-ethyl-heptyl, 1.1.3.3.tetramethyl butyl, and n - dodecyl. Heterocyclic systems formed by R1 and R2 are ethyleneimine, pyrrolidine, piperidine, hexamethyleneimine, morpholine, morpholino and thiomorpholino.  The compounds may be prepared by (1) oxidizing a mixture of the pentachloro thiophenol and the corresponding amine in an aqueous medium, or in solvents miscible with water, with e.g. sodium hypochlorite, iodine, hydrogen peroxide, ammonium persulphate and potassium ferricyanide, (2) reacting N - halogen derivatives of the amines-especially secondary amines, either with pentachloro thiophenol, in the presence of suitable hydrogen halide accepters, or with the alkali or alkaline earth metal or amine salts of pentachloro thiophenols in the aqueous phase or in solvents, (3) replacing the NH2 group in pentachloro phenyl sulphenamide, by primary or secondary amines, (4) reacting pentahalogen phenyl sulphene chlorides with the corresponding amines in the presence of a suitable hydrogen halide in an organic solvent or with excess amine. The sulphene chlorides may be prepared by the chlorination of pentachloro thiophenol in e.g. chloroform, carbon tetrachloride, or chlorobenzene at -10 DEG  to 50 DEG  C.  Examples are given.ALSO:Rubber vulcanization accelerators contain compounds of the general formula <FORM:0837159/IV (a)/1> where R1 and R2, which may be the same or different, are hydrogen, saturated or unsaturated hydrocarbon radicals, cycloalkyl, alkylaryl, or aryl radicals, or R1 and R2 together with the nitrogen atom may form a heterocyclic ring system which may also contain other hetero atoms.  Specified groups for R1 and R2 are hydrogen, ethyl, isopropyl, allyl, t-butyl, cyclohexyl, methyl, butyl, phenyl, benzyl, 2-ethylheptyl, 1.1.3,3, tetramethyl butyl, and n-dodecyl. Heterocyclic systems formed by R1 and R2 are ethylenimine, pyrrolidine, piperidine, hexamethyleneimine, morpholine, morpholino, and thiomorpholino.  The compounds may be used as vulcanization accelerators for natural and synthetic rubber or mixtures thereof, alone or in combination with other known accelerators.  When used with mixtures of natural and synthetic rubber, the mixtures are filled with carbon black, or contain light-coloured fillers.  Suitable synthetic rubbers are polymers of butadiene, dimethyl-butadiene, isoprene, isobutylene and their copolymers with e.g. styrene, a -methyl styrene, acrylonitrile, methacrylonitrile, acrylates, and methacrylates, or poly-chlorobutadiene and its copolymers with mono and/or di olefines. Suitable quantities of the pentachlorothiophenol sulphenamides are from 0.05 to 10% of the rubber content of the mixture.  Examples are given illustrating and comparing the advantages of the compounds of the invention with other vulcanization accelerators in various compositions.  Basic compositions mentioned are those containing the following natural rubber, a butadiene-styrene copolymer, a butadiene-acrylonitrile copolymer, a chlorobutadiene polymer, an isobutylene isoprene copolymer, together with some of the following: zinc oxide, zinc white, titanium dioxide, sulphur, stearic acid, various carbon blacks, wool fat, mineral oil plasticizer, paraffin wax, phenyl-b -naphthylamine, phenyl cyclohexyl p-phenylene diamine, methylene-bis-thioglycollic acid butylester, magnesium oxide, tetrarethylene and thiuramide sulphide.  Amongst the many vulcanization accelerators and mixtures thereof specified are the following known compounds: phenyl piperidine sulphenamide, 4 - chlorophenyl - piperidine sulphenamide, 2.3.5, trichlorophenyl piperidine sulphenamide, the corresponding diethyl, cyclohexyl and ethyl, sulphenamides, 2,3,5, trichlorophenyl diethylene sulphenamide, benzothiazyle 1-cyclohexyl sulphenamide, and the corresponding morpholyl and 2-diisopropyl, sulphenamide, and the following compounds of the invention, pentachlorophenyl cyclohexylethyl sulphenamide and corresponding compounds in which the cyclohexyl-ethyl group is replaced by diethyl, pyrrolidine, allyl, hexamethylenimine, piperidine, methyl, and morpholino.