Patent GB-491643-A (GB)
Title: Vulcanization of rubber
IPC: C08K5/00
Filed: 1938-02-04
Abstract: The vulcanization of rubber is accelerated by the addition to the mix of the reaction product of an alpha-halocyclohexanone and a dithio acid.  The halocyclohexanones employed must contain at least one halogen atom in the alpha position to the carbonyl group.  Other neutral or basic substituents may also be present, such as alkyl, aralkyl, aryl, alicyclic, alkoxy, aryloxy, amino, hydroxy and halogen in other than the alpha position.  The preferred alpha halogen atom is chlorine, but bromine, or even iodine may also be employed.  The dithio acid is employed in the form of its alkali metal or other water soluble salt.  Dithio acids mentioned include dithio carbamic acids, such as N-butyl-, cyclohexyl-, allyl-, and tetrahydro-alpha-furfuryl-dithiocarbamic acids, xanthogenic acids such as ethyl-, and amyl-xanthogenic acid, dithiofuroic acid, dithiobenzoic acid, dithioacetic acid, dithiolauric acid, dithio-oleic acid, dithioacrylic acid, dithiocrotonic acid, and dithiosalicylic acid.  In examples, (1) cyclohexanone is chlorinated by passing in a stream of gaseous chlorine in the presence of an aqueous suspension of calcium carbonate.  When the organic layer shows a chlorine content corresponding approximately to a mono-chlor compound, it is removed, and without purification reacted with sodium dimethyl-dithiocarbamate in acetone to give a mixture of dimethyl dithiocarbamyl mercapto-cyclohexanone, and di-(dimethylthiocarbanylmercapto) cyclohexanone which can be separated by fractional crystallization; (2) the disubstituted product is prepared in larger amount by allowing crude dichlorocyclohexanone and an aqueous acetone solution of sodium dimethyl-dithiocarbamate to stand for several days.  Examples are given to show the efficiency of the accelerators of the present invention when used in a standard rubber mix.ALSO:The vulcanization of rubber is accelerated by the addition to the mix of the reaction product of an alpha-halocyclohexanone and a dithio acid.  The halocyclohexanones employed must contain at least one halogen atom in the alpha position to the carbonyl group.  Other neutral or basic substituents may also be present such as alkyl, aralkyl, aryl, alicyclic alkoxy, aryloxy, amino, hydroxy and halogen in other than the alpha position.  The preferred alpha halogen atom is chlorine, but bromine or even iodine may also be employed.  The dithio acid is employed in the form of its alkali metal or other water soluble salt. Dithio-acids mentioned include dithiocarbamic acids such as N-butyl-, cyclohexyl-, allyl-, and tetrahydro-alpha-furfuryl dithiocarbamic acids, xanthogenic acids such as ethyl-, and amyl xanthogenic acid, dithiofuroic acid, dithiobenzoic acid, dithioacetic acid, dithiolauric acid, dithiooleic acid, dithioacrylic acid, dithiocrotonic acid, and dithiosalicyclic acid.  In examples: (1) cyclohexanone is chlorinated by passing in a stream of gaseous chlorine in the presence of an aqueous suspension of calcium carbonate.  When the organic layer shows a chlorine content corresponding approximately to a mono-chlor compound, it is removed, and without purification reacted with sodium dimethyldithiocarbamate in acetone to give a mixture of dimethyl-dithiocarbamyl mercapto cyclo-hexanone, and di(dimethylthiocarbamylmercapto) cyclohexanone which can be separated by fractional crystallization; (2) the disubstituted product is prepared in larger amount by allowing crude dichlorocyclohexanone and an aqueous acetone solution of sodium dimethyl-dithiocarbamate to stand for several days.  Examples are given to show the efficiency of the accelerators of the present invention when used in a standard rubber mix.