Patent GB-486109-A (GB)
Title: Improvements in vulcanization of rubber
IPC: C08K5/00
Filed: 1936-09-30
Abstract: The vulcanization of rubber other than in the form of liquid dispersions is accelerated by the addition to the mix of a primary amine addition product of a zinc salt of a dithiocarbamic acid derived from a secondary amine.  The amines which are used to form the addition products may be either saturated or unsaturated primary amines, and examples of suitable amines which are given include the following: alicyclic, phenalkyl, furfuryl, and tetrahydrofurfuryl primary amines, and aliphatic primary amines having not more than ten carbon atoms.  These amines are reacted with a zinc salt of a dithocarbamic acid derived from an amine having the formula <FORM:0486109/IV/1> where R is a radical selected from the group consisting of alkyl, tetrahydrofurfuryl, alicyclic and phenalkyl, and R1 is a radical selected from the group consisting of alkyl, tetrahydrofurfuryl and phenalkyl radicals, or R and R1 together may form a polymethylene chain which may be interrupted by oxygen.  A number of suitable amines are mentioned of which the following are typical: di-n-propyl-amine, N-methyl-cyclohexylamine, morpholine and symdibutyl-trimethylene diamine.  The reaction, which appears to be one of simple addition is preferably conducted in aqueous solution or suspension, but p  other solvents such as alcohol, benzene, xylene and gasoline may also be used.  In examples: (1) zinc dimethyl dithiocarbamate and cyclohexylamine are heated together in aqueous solution; (2) a mixture of amyl primary amines was added to a gasoline suspension of zinc dimethyl dithiocarbamate and the addition product filtered off.  This addition may also be carried out in aqueous suspension; (3) cyclohexylamine is added to a gasoline suspension of zinc pentamethylene dithiocarbamate and the mixture heated under reflux for a short time.  Tables are furnished to show the efficiency of the accelerators of the present invention when incorporated in a standard rubber mix.  Specification 484,299 is referred to.ALSO:The vulcanization of rubber other than in the form of liquid dispersions is accelerated by the addition to the mix of a primary amine addition product of a zinc salt of a dithiocarbamic acid derived from a secondary amine.  The amines which are used to form the addition products may be either saturated or unsaturated primary amines, and examples of suitable amines which are given include the following : alicyclic, phenalkyl, furfuryl, and tetrahydrofurfuryl primary amines, and aliphatic primary amines having not more than ten carbon atoms.  These amines are reacted with a zinc salt of a dithiocarbamic acid derived from an amine having the formula <FORM:0486109/V/1> where R is a radical selected from the group consisting of alkyl, tetrahydrofurfuryl, alicyclic and phenalkyl, and R1 is a radical selected from the group consisting of alkyl, tetrahydrofurfuryl, and phenalkyl radicals, or R and R1 together may form a pentamethylene chain which may be interrupted by oxygen.  A number of suitable amines are mentioned of which the following are typical; di-n-propylamine, N-methyl-cyclohexylamine, morpholine and symdibutyltrimethylene-diamine.  The reaction which appears to be one of simple addition is preferably conducted in aqueous solution or suspension, but other solvents such as alcohol, benzene, xylene and gasoline may also be used. In examples, (1) zinc dimethyldithiocarbamate and cyclohexylamine are heated together in aqueous solution : (2) a mixture of amyl primary amines was added to a gasoline suspension of zinc dimethyldithiocarbamate and the addition product filtered off. This addition may also be carried out in aqueous suspension ; (3) cyclohexylamine is added to a gasoline suspension of zinc pentamethylene dithiocarbamate, and the mixture heated under reflux for a short time.  Specification 484,299 is referred to.