Abstract: The invention provides a composition comprising a mixture or reaction mixture of a carbodithioic acid of formula: (I) or its internal salt; and at least one compound independently selected from a natural or synthetic rubber curing or vulcanization accelerator, activator or retarding agent. wherein R? and R? are independently selected from a C2-C18 aliphatic moiety; aromatic moiety; alicyclic moiety; aromatic heterocyclic moiety; and aliphatic heterocyclic moiety or R? and R? may together form part of an aromatic heterocyclic ring moiety or aliphatic heterocyclic ring moiety.

Abstract: The invention provides a composition comprising a mixture or reaction mixture of a carbodithioic acid of formula: (I) or its internal salt; and at least one compound independently selected from a natural or synthetic rubber curing or vulcanisation accelerator, activator or retarding agent. wherein R? and R? are independently selected from a C2-C18 aliphatic moiety; aromatic moiety; alicyclic moiety; aromatic heterocyclic moiety; and aliphatic heterocyclic moiety or R? and R? may together form part of an aromatic heterocyclic ring moiety or aliphatic heterocyclic ring moiety.

Abstract: A vulcanizable composition comprises sulfur-vulcanizable rubber, sulfur or a sulfur-donor, a zinc compound, and a sulfur-containing amine of the formulaR.sup.1 --S.sub.n --R--NR.sup.2 R.sup.3wherein R is a divalent radical comprising a chain of at least 2 C atoms, R.sup.1 is an organic radical, and R.sup.2 and R.sup.3 are each H or an organic radical, provided that NR.sup.2 R.sup.3 is not NH(C.sub.1-6 alkyl), and n is an integer, or a salt thereof, provided that the amine is not 3-(methylthio)propylamine. The amine is preferably cystamine.