Patent GB-418376-A (GB)
Title: Improvements in and relating to the vulcanization of rubber
IPC: C08K5/00
Filed: 1933-01-20
Abstract: The Specification as open to inspection under Sect. 91 indicates that the zinc salt of carboxymethyl cyclopentamethylenedithiocarbamate, (C5H10NCSSCH2COO)2Zn, is obtainable from a salt of cyclopentamethylenedithiocarbamic acid and zinc chloracetate.  This subject-matter does not appear in the Specification as accepted.ALSO:As accelerators in vulcanizing indiarubber, use is made of compounds of the formula RR<1>NCSSCHR<11>COOM, where R and R<1> are alkyl, aryl or aralkyl radicles or form, with the nitrogen atom, a heterocyclic ring, R<11> is hydrogen or an alkyl group, and M is hydrogen or an ammonium or substituted ammonium group such as dibutylammonium, dibenzylammonium, or N : N<1>-diphenylguanidinium. These compounds are obtainable by treating soluble salts of dithiocarbamic acids of the formula RR<1>NCSSH with appropriate salts of acids of the formula XCHR<11>COOH, where X is halogen.  Thus, sodium dimethyl-dithiocarbamate may be treated with ammonium chloracetate to yield the compound (CH3)2 NCSSCH2COONH4. Carboxymethyl cyclopentamethylene - dithiocarbamate (C5H10 NCSSCH2COOH) and its diphenylguanidine salt are similarly obtainable. Samples have been filed under Sect. 2 (5) of a -carboxypropyl cyclopentamethylenedithiocarbamate and its piperidine salt; the former is prepared by treating ammonium a -bromobutyrate with sodium cyclopentamethylene - dithiocarbamate and acidifying the product; the piperidine salt is prepared by warming the acid with piperidine in the presence of benzene.  Specifications 353,871, 372,623 and 406,379 are referred to.  The Specification as open to inspection under Sect. 91 describes the use of compounds of the formula ((RR<1>NCSS)nR<11>COO)nM, where R and R<1> have the meanings given above, R<11> is "carbon or carbon and hydrogen," n is one or more, and M is hydrogen, a metal, an alkyl, aryl or aralkyl radicle, or a salt-forming radicle such as an ammonium or substituted ammonium group.  The following examples of the preparation of such compounds are given:--(1) sodium dimethyldithiocarbamate (2 mols.) is condensed with ammonium dichloracetate (1 mol.) to yield the compound ((CH3)2NCSS)2CHCOONH4 which is acidified to yield the free acid; (2) sodium diethyldithiocarbamate (2 mols.) is condensed with ammonium dichloracetate (1 mol.) and the product is acidified; (3) sodium cyclopentamethylenedithiocarbamate (2 mols.) is condensed with ammonium dichloracetate (1 mol.) and the product is acidified to yield the compound (C5H10NCSS)2CHCOOH; (4) sodium diethyldithiocarbamate (2 mols.) is condensed with ethyl dichloracetate (1 mol.); (5) sodium dimethyldithiocarbamate (2 mols.) is condensed with ethyl dichloracetate (1 mol.); (6) the product of example 1 is converted into its diphenylguanidine salt. Other compounds stated to be similarly obtainable are carboxymethyl cyclopentamethylenedithiocarbamate cyclohexylammonium salt (C5H10NCSSCH2COOH.NH2C6H11), piperidinium salt, zinc salt, p-phenylenediamine salt, and ethylenediamine salt.  Reference is made also to the production of the compound (CH3)2NCSSCHClCOONH4 from equimolecular amounts of sodium dimethyldithiocarbamate and ammonium dichloracetate.  This subject-matter does not appear in the Specification as accepted.ALSO:As accelerators in vulcanizing indiarubber, use is made of compounds of the formula RR1NCSSCHR11COOM, where R and R1 are alkyl, aryl or aralkyl radicles or form, with the nitrogen atom, a heterocyclic ring, R11 is hydrogen or an alkyl group, and M is hydrogen or an ammonium or substituted ammonium group such as dibutylammonium, dibenzylammonium, or N : N1-diphenylguanidinium.  These compounds are obtainable by treating soluble salts of dithiocarbamic acids of the formula RR1NCSSH with appropriate salts of acids of the formula XCHR11COOH, where X is halogen.  Thus, sodium dimethyl-dithiocarbamate may be treated with ammonium chloracetate to yield the compound (CH2)2 NCSSCH2COONH4. Carboxymethyl cyclopentamethylenedithiocarbamate (C5H10NCSSCH2 COOH) and its diphenylguanidine salt are similarly obtainable.  Samples have been filed under Sect. 2 (5) of a -carboxypropyl cyclopentamethylenedithiocarbamate and its piperidine salt; the former is prepared by treating ammonium - a  - bromobutyrate with sodium cyclopentamethylenedithiocarbamate and acidifying the product; the piperidine salt is prepared by warming the acid with piperidine in the presence of benzene.  Particulars are given of the use of the samples and of the other compounds specified above as vulcanization accelerators in rubber mixtures containing also zinc oxide, sulphur, and stearic acid.  Specifications 353,871, 372,623, and 406,379 are referred to.  The Specification as open to inspection under Sect. 91 describes the use of compounds of the formula ((RR1NCSS)nR11COO)nM, where R and R1 have the meanings given above, R11 is "carbon or carbon and hydrogen," n is one or more, and M is hydrogen, a metal, an alkyl, aryl or aralkyl radicle, or a salt-forming radicle such as an ammonium or substituted ammonium group.  The following examples of the preparation of such compounds are given: (1) sodium dimethyldithiocarbamate (2 mols.) is condensed with ammonium dichloracetate (1 mol.) to yield the compound ((CH3)2NCSS)2CHCOONH4, which is acidified to yield the free acid; (2) sodium diethyldithiocarbamate (2 mols.) is condensed with ammonium dichloracetate (1 mol.) and the product is acidified; (3) sodium cyclopentamethylenedithiocarbamate (2 mols.) is condensed with ammonium dichloracetate (1 mol.) and the product is acidified to yield the compound (C5H10NCSS)2CHCOOH; (4) sodium diethyldithiocarbamate (2 mols.) is condensed with ethyl dichloracetate (1 mol.); (5) sodium dimethyldithiocarbamate (2 mols.) is condensed with ethyl dichloracetate (1 mol.); (6) the product of example 1 is converted into its diphenylguanidine salt. Other compounds stated to be similarly obtainable are carboxymethyl cyclopentamethylenedithiocarbamate cyclohexylammonium salt (C5H10NCSSCH2COOH.NH2C6H11), piperidinium salt, zinc salt, p-phenylenediamine salt, and ethylenediamine salt.  Particles are given of the use of the products specified above as vulcanization accelerators in rubber mixtures containing also zinc oxide, sulphur, and stearic acid, with or without diphenylguanidine.  Reference is made also to the production of the compound (CH3)2NCSSCHCECOONH4 p from equimolecular amounts of sodium dimethyldithiocarbamate and ammonium dichloracetate.  This subject-matter does not appear in the Specification as accepted.