Patent GB-392047-A (GB)
Title: The manufacture and application of new accelerators for vulcanisation
IPC: C08K5/00
Filed: 1932-09-16
Abstract: The sulphhydryl group of compounds containing the groupings:--<FORM:0392047/IV/1> or <FORM:0392047/IV/2> is etherified by an aryl radicle containing a nitro group and in m-position to the nitro group, the group <FORM:0392047/IV/3> , wherein x indicates a substituted or unsubstituted alkyl, aryl, aralkyl, alkoxy, or hydroaryl radicle or a substituted or unsubstituted amino group. Thus a salt of the sulphhydryl compound may be reacted with an appropriate nitrohalogenaryl compound in an aqueous or organic medium while gently heating. Suitable sulphhydryl compounds are mercaptoarylthiazoles such as 2 - mercaptobenzthiazole, 2 - mercapto - 1<1>.2<1>-napththothiazole, which compounds may contain monovalent substituents such as chlorine or bromine, nitro, amino, dimethylamino, alkyl (methyl, ethyl, butyl), aryl (phenyl), or alkoxy (methoxy, ethoxy) groups; or dithiocarbamates derived from secondary amines such as dimethyl-, diethyl-, dibenzyl-, dicyclohexylamines, methylethylamine, ethylcyclohexylamine, N-methylaniline, piperidine, morpholine, thiomorpholine, hexahydrocarbazole.  Suitable nitrohalogenaryl compounds are 2-chloro-5-nitrophenyl-1-sulphonic acid benzyl ester, 1-chloro-2-nitrophenyl-4-sulphonamide, 1-bromo-2-nitrophenyl-4-sulphomethylamide, 3 - nitro - 4 - chlorbenzene - 1 - sulphonanilide, 3-nitro-4-chlordiphenylsulphone - (1) (prepared by reacting 3 - nitro - 4 - chlorbenzene - sulphochloride with benzene and aluminium chloride) and 4 - chloro - 3 - nitrophenyl - 1 - methylsulphone (prepared by reacting 4-chlorphenylsulphinic acid with methyliodide in methanol and nitrating the product at about 0 DEG  C).  Those nitrohalogenaryl compounds containing a hydroaryl-sulphone group may be prepared in a similar manner to the above methylsulphone derivative by using cyclohexyliodide; those containing aralkylsulphone groups may be prepared, for example, by converting 1-amino-3-nitro-4-chlorbenzene into the 1-mercapto derivative by diazotization and reaction with a xanthogenate, reacting this product with an aralkyl halogenide and oxidizing the product to the sulphone by hydrogen peroxide.  In examples the following reaction products are specified: 1-chloro-2-nitrobenzene - 4 - sulphomethylamide with dimethyldithiocarbamate, pentamethylenedi-thiocarbamate and 2-mercaptobenzthiazole, 3-nitro-4-chlordiphenylsulphone with dimethyl-dithiocarbamate and mercaptobenzthiazole, 1 - chloro - 2 - nitrobenzene - 4 - sulphoanilide with dimethyldithiocarbamate and 2-mercaptobenzthiazole.  Specifications 340,574, 340,951, and 342,330 are referred to. ALSO: Natural rubber and artificial rubber-like masses are vulcanized in the presence of accelerators containing the groupings: <FORM:0392047/V/1> or <FORM:0392047/V/2> wherein the NO2 group stands in o- or p-position to the sulphur atom (1), and in mposition to the sulphur atom (2), and wherein x indicates alkyl, aryl, aralkyl, alkoxy, hydroaryl or amino group.  These accelerators are prepared by etherifying the sulphhydryl group of compounds containing the grouping: <FORM:0392047/V/3> or <FORM:0392047/V/4> by an aryl radicle containing a nitro group and in mposition to the nitro group, the group <FORM:0392047/V/5> , wherein x indicates a substituted or unsubstituted alkyl, aryl, aralkyl, alkoxy or hydroaryl radicle or a substituted or unsubstituted amino group.  Thus a salt of the sulphhydryl compound may be reacted with an appropriate nitrohalogenaryl compound in aqueous or organic medium while gently heating. Suitable sulphhydryl compounds are mercaptoarylenethiazoles, such as 2-mercaptobenzthiazole 2 - mercapto - 11 : 21 - naphthothiazole which may contain monovalent substituents such as chlorine or bromine, nitro, amino, dimethylamino, alkyl (methyl, ethyl, butyl), aryl (phenyl), or alkoxy (methoxy, ethoxy) groups; or dithiocarbamates derived from secondary amines such as dimethyl-, diethyl-, dibenzyl-, dicyclohexylamines, methylethylamine, ethylcyclohexylamine, N-methylaniline, piperidine, morpholine, thiomorpholine, hexahydrocarbazole. Suitable nitrohalogenaryl compounds are 2-chloro-5-nitrophenyl-1-sulphonic acid benzyl esters, 1-chloro-2-nitrophenyl-4-sulphonamide, 1 - bromo - 2 - nitrophenyl - 4 - sulphonamide, 1 - chloro - 2 - nitrophenyl - 4 - sulphomethylamide, 3 - nitro - 4 - chlorbenzene - 1-sulphonanilide, 3 - nitro - 4 - chlordiphenylsulphone-(1) (prepared by reacting 3-nitro-4-chlorobenzene - sulphochloride with benzene and aluminium chloride) and 4-chloro-3-nitrophenyl-1-methylsulphone (prepared by reacting 4-chlorphenylsulphinic acid with methyl iodide in methanol and nitrating the product at about 0 DEG  C.  Those nitrohalogenaryl compounds containing a hydroarylsulphone group may be prepared in a manner similar to the above methylsulphone derivative; those containing aralkylsulphone groups may be prepared, for example, by converting 1-amino-3-nitro-4-chlorbenzene into the 1-mercapto derivative by diazotization and reaction with a xanthogenate, reacting this product with an aralkyl halogenide and oxidizing the product to the sulphone by hydrogen peroxide.  These accelerators are in some cases advantageously employed with other accelerators and are incorporated into the rubber mixes together with any other desired ingredients, filling materials, pigments, softeners and antiperishing agents.  They possess a good critical temperature and compared with the products of Specifications 340,574, 340,951, and 342,330, [all in Group IV], they are distinguished by being powerful accelerators causing no discoloration of the vulcanizates.  Examples are given showing the accelerating properties of some of the reaction products derived from the components listed above in a rubber-mix.  Artificial rubber-like masses may be similarly vulcanized.