Patent GB-442978-A (GB)
Title: Improvements in vulcanizing rubber
IPC: C08K5/00
Filed: 1935-03-13
Abstract: Arylthiazyl esters of dihydrocarbon substituted dithiocarbamic acids in which at least one of the substituents is alicyclic, which are used as accelerators of vulcanization for rubber are prepared either by the interaction of a halogen aryl thiazole and a salt of the desired dithocarbamic acid or by the interaction of a halogen aryl thiazole and the ingredients necessary to form the required dithiocarbamic acid in situ.  The dithiocarbamates employed may be represented by the general formula <FORM:0442978/IV/1> Where R1 is an alicyclic group, R2 is any hydrocarbon radical such as alicyclic, alkyl, aryl or aralkyl and M is any replaceable salt forming radical such as sodium potassium, ammonium calcium or barium which does not seriously impair the solubility of the dithiocarbamate in the solvent used to effect the reaction.  In examples: (1) equimolecular proportions of 2-chlor-6-nitrobenzothiazole, dicyclo-hexylamine, carbon bisulphide and sodium hydroxide are refluxed 1\ba1/2\be--3 hours in ethyl alcohol solution.  The 6-nitro-benzothiazyl - 2 - dicyclohexyl - dithiocarbamate is purified by recrystallization from alcohol; (2) in a similar manner 6-nitrobenzothiazyl-2-N-ethyl-cyclohexyl dithiocarbamate is prepared from N-ethyl-cyclohexylamine, 2-chlor-6-nitrobenzothiazole, carbon disulphide and sodium hydroxide.  Other halogen aryl thiazoles are mentioned together with a list of salts of secondary alicyclic dithiocarbamates with which they may be reacted to produce the accelerators of the present invention.  Specification 302,142, [Class 2 (iii)], is referred to.ALSO:The vulcanization of rubber is accelerated by the addition to the mix of an arylthiazyl ester of a dihydrocarbon substituted dithiocarbamic acid in which at least one of the substituents is alicyclic.  The preferred halogen aryl thiazoles are 2-chlor aryl thiazoles and the preferred member is 2-chlor-6-nitro benzothiazole.  The dithiocarbamates employed may be represented by the general formula <FORM:0442978/V/1> Where R is an alicyclic group, R2 is any hydrocarbon radical such as alicyclic, alkyl, aryl or aralkyl, and M is any replaceable salt-forming radical such as sodium potassium, ammonium, calcium or barium which does not seriously impair the solubility of the dithiocarbamate in the solvent used to effect the reaction.  The secondary alicyclic dithiocarbamates may be first prepared by the known method of interacting carbon bisulphide, an alkali and a secondary amine and then reacted with the thiazole, or the dithiocarbamate may be formed in situ in a suspension of the 2-halogen thiazole in a suitable solvent such as ethyl alcohol.  In examples: (1) equimolecular proportions of 2-chlor-6-nitrobenzothiazole, dicyclo-hexylamine, carbon bisulphide and sodium hydroxide are refluxed 1 1/2 -3 hours in ethyl alcohol solution.  The 6-nitro-benzothiazyl-2-dicyclohexyl-dithiocarbamate is purified by recrystallization from alcohol; (2) in a similar manner 6-nitro-benzothiazyl-2-N-ethyl cyclohexyl dithiocarbamate is prepared from N-ethyl cyclohexylamine, 2-chlor-6-nitro-benzothiazole, carbon bisulphide and sodium hydroxide.  Other halogen aryl thiazoles are mentioned together with a list of salts of secondary alicyclic dithiocarbamates with which they may be reacted to produce the accelerators of the present invention.  Tests are also quoted to show the efficiency of the accelerators.  Specification 302,142, [Class 70], is referred to.