Patent GB-391120-A (GB)
Title: Improvements in or relating to accelerators for the vulcanisation of rubber
IPC: C08K5/00
Filed: 1931-10-14
Abstract: Dithiocarbamate derivatives are prepared by reacting a compound of the formula x -- S -- Ar, wherein x = halogen or the residue --SNC and Ar = an aryl residue which may be substituted, with a compound of the formula <FORM:0391120/IV/1> Wherein Me = a metal atom or the residue of an organic base, R = an aliphatic, aliphatic-aromatic, aromatic or hydroaromatic residue, R1 = an aliphatic, aliphatic-aromatic or hydroaromatic residue, or R and R1 jointly stand for an alkylene group which may be interrupted by heterogenous atoms, the reaction being effected at a temperature not exceeding 60 DEG  C. Reaction may be effected with cooling or without external heating or cooling of the reaction mixture and in presence of an inert non-basic solvent.  Substituents in the residue Ar may be halogen, nitro, aldehyde or alkyl groups or substituted sulphonic or carboxylic groups (the latter does not include acyl groups) and suitable components specified are phenyl sulphur chloride, nitrophenyl sulphur chlorides, tolyl sulphur chlorides, 2-nitro-4-formylphenyl sulphur bromide and 1-chlornaphthyl-2-sulphur chloride.  Suitable dithiocarbamic acids may be derived from dimethylamine, dibutylamine, dicyclohexylamine, methylaniline, ethylcyclohexylamine, dibenzylamine, piperidine, morpholine, diethanolamine, hexahydroquinoline and perhydrocarbazole.  The products are water-insoluble arylthio derivatives of dithiocarbamates possessing a favourable critical temperature as accelerators in the vulcanization of natural and artificial rubber.  In examples, (1) a dimethyldithiocarbamate is reacted with p- and o-nitrophenyl sulphur chloride to give p- and o-nitroarylthio derivatives respectively; (2) o-nitrophenyl sulphur chloride is reacted with sodium pentamethylenedithiocarbamate and sodium ethylcyclohexyldithiocarbamate; (3) details are given illustrating the accelerating properties of the foregoing products in a rubber mix.  The accelerators impart no unpleasant taste or smell or discolouration to the vulcanized products, and give satisfactory results with rubber-like masses obtainable by the polymerization of butadiene, isoprene or homologues thereof in the presence or not of other polymerizable substances.ALSO:Vulcanization accelerators are prepared by reacting a compound of the formula x - S - Ar wherein x = a halogen or the residue of - SNC and Ar = an aryl residue which may be substituted, with a compound of the formula <FORM:0391120/V/1> wherein Me = a metal atom or the residue of an organic base, R = an aliphatic, aliphatic-aromatic, aromatic or hydroaromatic residue, R1 = an aliphatic, aliphatic-aromatic or hydroaromatic residue, or R and R1 jointly stand for an alkylene group which may be interrupted by heterogenous atoms, the reaction being effected at a temperature not exceeding 60 DEG  C.  The products are water insoluble arylthio derivatives of dithiocarbamates possessing a favourable critical temperature in the vulcanization process and imparting no unpleasant taste or smell or discolouration to the vulcanized products.  They also give satisfactory results with artificial rubber-like masses obtainable, for example, by the polymerization of butadrene, isoprene or homologues thereof in the presence or not of other polymerizable substances.  In an example, details are given illustrating the accelerating properties of the o-nitrophenylthio derivatives of dimethyldithiocarbamate, pentamethylenedithiocarbamate and ethylcyclohexyldithiocarbamate and of the p-nitrophenylthio derivative of dimethyldithiocarbamate, in a rubber mix.