GB441653A - Improvements in or relating to the vulcanisation of rubber - Google Patents

Abstract

The vulcanization of rubber is accelerated without risk of scorching by the addition to the mix of compounds of the general formula <FORM:0441653/IV/1> where R represents an organic radical and X is a grouping which together with the carbon and sulphur atoms represents the composition of a negative radical of an organic accelerator of the dithio class. Examples of accelerators of the dithio class which may be converted into the accelerators of the present invention are mercaptoarylene thiazoles, alkyl xanthates, alkyl- or aryl- or alkyl-aryl- or hydrogenated aryl-dithiocarbamates, or dithio acids. The conversion may be carried out by the condensation of the above dithio accelerators with aryl selenohalides or selenocyanides, of which the preferred examples are phenyl selenochloride, a nitrophenyl selenobromide, or a nitrophenyl selenocyanide. The accelerators of the present invention may with advantage be used in conjunction with other known accelerators such as the aryl guanidines, and in particular diphenylguanidine and diorthotolylguanidine, or thiuram disulphides such as tetraethylthiuram disulphide. In examples: (1) the sodium salt of mercaptobenzothiazole is reacted with o-nitrophenyl seleno-monobromide to give benzthiazyl - o - nitrophenyl selenosulphide; (2) Sodium diethyldithiocarbamate is reacted with o-nitrophenyl selenomonobromide to give the o-nitrophenyl selenosulphide of diethyldithiocarbamic acid; (3) potassium isopropyl xanthate is reacted with o-nitrophenyl selenomonobromide to give the o-nitrophenyl selenosulphide of isopropyl xanthic acid; (4) mercaptobenzothiazole is reacted with o-nitrophenyl selenomonobromide to give the same product as was obtained in example (1); (5) the sodium diethyldithiocarbamate of example (2) is replaced by sodium pentamethylene dithiocarbamate to give the corresponding selenosulphide; (6) Sodium diethyldithiocarbamate is reacted with o-nitro-phenyl selenocyanide to give the same product as obtained in example (2). o-Nitrophenyl-selenocyanide is prepared by adding sodium acetate to a diazotized solution of o-nitraniline until neutral followed by a solution of potassium selenocyanide. o-Nitrophenyl-selenomonobromide is prepared from the corresponding selenocyanide by the action of bromine in chloroform solution.ALSO:The vulcanization of rubber is accelerated without risk of scorching by the addition to the mix of compounds of the general formula <FORM:0441653/V/1> where R Represents an organic radical and X is a grouping which together with the carbon and sulphur atoms represents the composition of a negative radical of an organic accelerator of the dithio class. Examples of accelerators of the dithio class which may be converted into accelerators of the present invention are mercaptoarylene thiazoles, alkyl xanthates, alkyl- or aryl- or alkyl-aryl- or hydrogenated aryl dithiocarbamates, or dithio acids. The conversion may be carried out by the condensation of the above dithio accelerators with aryl selenocyanides or selenohalides of which the preferred examples are phenyl selenochloride a nitrophenyl selenobromide or a nitrophenyl selenocyanide. The accelerators of the present invention may with advantage be used in conjunction with other known accelerators such as the aryl guanidines, and in particular diphenylguanidine or diortholoylguanidine, or thiuram disulphides such as tetraethylthiuram disulphide. In examples: (1) The sodium salt of mercaptobenzothiazole is reacted with o-nitrophenylselenomonobromide to give benzthiazyl-o-nitrophenyl selenosulphide. (2) Sodium diethyldithiocarbamate is reacted with o-nitrophenyl selenomonobromide to give the o-nitrophenyl selenosulphide of diethyldithiocarbamic acid. (3) Potassium isopropyl xanthate is reacted with o-nitrophenyl selenomonobromide to give the o-nitrophenyl selenosulphide of isopropyl xanthic acid. (4) Mercaptobenzothiazole is reacted with o-nitrophenyl selenomonobromide to give the same product as was obtained in example (1). (5) The sodium diethyldithiocarbamate of example (2) is replaced by sodium pentamethylene dithiocarbamate to give the corresponding selenosulphide. (6) Sodium diethyldithiocarbamate is reacted with o-nitrophenyl selenocyanide to give the same product as obtained in example (2).