Patent GB-488691-A (GB)
Title: Improvements in vulcanization of rubber
IPC: C08K5/00
Filed: 1937-11-09
Abstract: The vulcanization of rubber is accelerated by the addition to the mix of the reaction product of a thiuronium halide and a water soluble salt of a dithio acid, preferably an alkali metal salt. The compounds are believed to possess the general formula <FORM:0488691/IV/1> where R and R1 may be hydrogen, or an alkyl, aralkyl, alicyclic or aryl group, substituted or not, R2 is a dithiocarboxylate radical such as a dithiocarbamyl or xanthyl group, and R3 is an organic radical such as alkyl, alicyclic, aralkyl, carboxyalkyl, or aromatic acyl radical. The compounds are prepared by bringing the reactants together in solution in water, alcohol, acetone, or mixtures thereof preferably at a temperature of 0-10 DEG  C.  Thiuronium halides mentioned include S-benzyl thiuronium chloride, S-(carboxymethyl) thiuronium chloride S-benzyl-N-cyclohexylthiuronium chloride and S - benzyl - NN1 - dicyclohexylthiuronium chloride.  Among the dithio acids, the salts of which are reacted with the thiuronium halide there are mentioned the dithiocarbamic acids such as N-butyl-, benzyl-, beta phen - ethyl-, phenyl-, alpha furfuryl-, and para-ethoxycyclohexyl-dithiocarbamic acid, the xanthogenic acids such as methyl-, ethyl-, and amyl xanthogenic acid, dithiofuroic acid, dithiobenzoic acid, dithioacetic acid, dithiolauric acid, dithio-oleic acid, dithio-acrylic acid, dithiocrotonic acid, phenyl dithioacetic acid, o-amino dithiobenzoic acid and dithiosalicylic acid.  In examples: (1) An aqueous solution of sodium penta-methylene dithiocarbamate is dropped slowly into an aqueous solution of S-benzylthiuronium chloride to yield as a precipitate diamino (benzylmercapto) methyl-1-dithio-piperidine carboxylate.  (2) S-carboxymethylthiuronium chloride and sodium pentamethylene dithiocarbamate are reacted in aqueous solution at -5 DEG  C. to give diamino (carboxymethylmercapto) methyl-1-dithiopiperidine carboxylate.  (3) S-n-butyl-thiuronium bromide and sodium pentamethylene dithiocarbamate are reacted in aqueous solution at 0 DEG  C. to give diamino (n-butylmercapto) methyl-1-dithiopiperidine carboxylate.  (4) S-allylthiuronium bromide and sodium pentamethylene dithiocarbamate are reacted in aqueous solution at 0 DEG  C. to give diamino (allylmercapto) methyl-1-dithiopiperidine carboxylate.  (5) S-benzylthiuronium chloride and sodium dithiobenzoate are reacted in aqueous solution at 5 DEG  C. to give diamino (benzylmercapto) methyl phenyl carboxylate.  (6) S-benzylthiuronium chloride and ammonium dithiopyromucate are reacted in aqueous solution to give diamino (benzylmercapto) methyl furfuryl carboxylate.  (7) S-benzylthiuronium chloride and potassium ethyl xanthate are reacted in aqueous solution at 5 DEG  C. to give diamino (benzylmercapto) methyl ethoxy-carboxylate.  The accelerators of the present invention may be used either alone or in the presence of basic nitrogen containing accelerators, of which diphenyl guanidine is the preferred example. Other nitrogen containing auxiliary accelerators which are mentioned include di-o-tolyl guanidine, benzyl amine, 2 : 4-diamino diphenylamine, p-p1-diamino-diphenyl-methane and the neutral phthalate and succinate of diphenylguanidine, urea and urea succinate.  The thiuronium halides are prepared by the interaction of a thiourea or a substituted thiourea with an organic halide.  Ureas mentioned include mono-p-ethoxy-cyclohexylthiourea, monohexahydro o or p-tolylthiourea, monoethyl thiourea and di-N-N1-(p-methoxycyclohexyl thiourea.  A number of organic halides are mentioned of which the following are typical: n-heptyl-, n-amyl-, n-propyl-bromide, o-, m-, or p-nitro-or ethoxy-benzyl chloride, mono halogenated aliphatic carboxylic acids such as alpha chlor propionic acid, alpha brom butyric acid, alpha brom methyl butyrate, chlor butyl acetate and dichlor acetic acid.ALSO:The vulcanization of rubber is accelerated by the addition to the mix of the reaction product of a thiuronium halide and a water soluble salt of a dithio acid, preferably an alkali metal salt. The compounds are believed to possess the general formula <FORM:0488691/V/1> where R and R1 may be hydrogen, or an alkyl, aralkyl, alicyclic or aryl group, substituted or not, R2 is a dithiocarboxylate radical such as a dithiocarbamyl or xanthyl group, and R3 is an organic radical such as alkyl, alicyclic, aralkyl, carboxyalkyl, or aromatic acyl radical.  The compounds are prepared by bringing the reactants together in solution in water, alcohol, acetone, or mixtures thereof preferably at a temperature of 0-10 DEG C.  Thiuronium halides mentioned include S-benzyl thiuronium chloride, S-(carboxymethyl) thiuronium chloride, S-benzyl-N-cyclohexylthiuronium chloride and S-benzyl-NN1-dicyclohexylthiuronium chloride.  Among the dithio acids, the salts of which are reacted with the thiuronium halide there are mentioned the dithiocarbamic acids such as N-butyl-, benzyl-, beta phenethyl-, phenyl-, alpha furfuryl-, and para-ethoxy-cyclohexyl-dithiocarbamic acid, the xanthogenic acids such as methyl-, ethyl-, and amyl xanthogenic acid, dithiofuroic acid, dithiobenzoic acid, dithioacetic acid, dithiolauric acid, dithio-oleic acid, dithioacrylic acid, dithiocrotonic acid, phenyl dithioacetic acid, o-amino dithiobenzoic acid and dithiosalicylic acid.  In examples: (1) An aqueous solution of sodium pentamethylene dithiocarbomate is dropped slowly into an aqueous solution of S-benzylthiuronium chloride to yield as a precipitate diamino (benzylmercapto) methyl-1-dithio-piperidine carboxylate; (2) S-carboxymethylthiuronium chloride and sodium pentamethylene dithiocarbamate are reacted in aqueous solution at -5 DEG C to give diamino (carboxymethylmercapto, methyl-1-dithiopiperidine carboxylate; (3) S-n-butyl-thiuronium bromide and sodium pentamethylene dithiocarbamate are reacted in aqueous solution at 0 DEG C to give diamino (n-butylmercapto) methyl-1-dithiopiperidine carboxylate; (4) S-allylthiuronium bromide and sodium pentamethylene dithiocarbamate are reacted in aqueous solution at 0 DEG C to give diamino (allylmercapto) methyl-1-dithiopiperidine carboxylate; (5) S-benzylthiuronium chloride and sodium dithiobenzoate are reacted in aqueous solution at 5 DEG C to give diamino (benzylmercapto) methyl phenyl carboxylate; (6) S-benzylthiuronium chloride and ammonium dithiopyromucate are reacted in aqueous solution to give diamino (benzylmercapto) methyl furfuryl carboxylate; (7) S-benzylthiuronium chloride and potassium ethyl xanthate are reacted in aqueous solution at 5 DEG C. to give diamino (benzylmercapto) methyl ethoxy-carboxylate.  The accelerators of the present invention may be used either alone or in the presence of basic nitrogen containing accelerators of which diphenyl guanidine is the preferred example. Other nitrogen containing auxiliary accelerators which are mentioned include di-o-tolyl guanidine, benzyl amine, 2 : 4-diamino diphenylamine, p-p1-diamino-diphenyl-methane and the neutral phthalate and succinate of diphenylguanidine, urea and urea succinate.  The thiuronium halides are prepared by the interaction of a thiourea or a substituted thiourea with an organic halide.  Ureas mentioned include mono-p-ethoxy-cyclohexyl-thiourea, monohexahydro o or p-tolyl-thiourea, monoethyl thiourea and di-N-N1-(p-methoxycyclohexyl) thiourea.  A number of organic halides are mentioned of which the following are typical: n-heptyln-amyl-, n-propyl-bromide-o-, m-, or p-nitro- or ethoxy-benzyl chloride, mono halogenated aliphatic carboxylic acids such as alphachlor propionic acid, alpha brom butyric acid, alpha brom methyl butyrate, chlor butyl acetate and dichlor acetic acid.