Patent GB-484299-A (GB)
Title: Improvements in vulcanization of rubber
IPC: C08K5/00
Filed: 1936-09-30
Abstract: The vulcanization of liquid rubber dispersions is accelerated by the addition thereto of an amine addition product of the zinc salt of a dithiocarbamic acid derived from a secondary amine. The amines which are used to form the addition products may be either primary or secondary amines, and examples of types of suitable amines which are given include the following: alicyclic, phenalkyl, furfuryl and tetrahydrofurfuryl primary amines, aliphatic primary amines having not more than ten carbon atoms, N-alkyl alicyclic secondary amines in which the alkyl group has not more than five carbon atoms, dialkyl alkylene diamines in which the alkyl and alkylene groups have not more than five carbon atoms each, N-alkyl phenalkyl secondary amines in which the alkyl group has not more than five carbon atoms, dialkyl amines having not more than eight carbon atoms, N-alkyltetrahydrofurfuryl secondary amines in which the alkyl group has not more than five carbon atoms, and polymethylene secondary amines in which the polymethylene chain may be interrupted by an oxygen atom. Numerous examples of amines which fall into the above groups are mentioned.  These amines are reacted with a zinc salt of a dithiocarbamic acid derived from an amine having the formula <FORM:0484299/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, or R and R1 together 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, N-methyl tetrahydroalpha-furfurylamine, di-(beta-phenethyl)amine, morpholine, sym-ethylene diamine, pipecoline, and N-methyl-ethyl amine.  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 or gasoline may be used. In examples, (1) cyclohexylamine and zinc dimethyldithiocarbamate are heated together in aqueous solution, (2) mixed amyl primary amines are added to a gasoline suspension of zinc dimethyldithiocarbamate, (3) cyclohexylamine is added to a gasoline suspension of zinc pentamethylene dithiocarbamate and the mixture heated for a short time under reflux.  Tables are furnished to show the efficiency of the accelerators of the present invention when incorporated in a standard rubber mix. Specifications 405,099 and 423,308, [both in Group V], are referred to.ALSO:The vulcanization of liquid rubber dispersions is accelerated by the addition thereto of an 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 primary or secondary amines and examples of types of suitable amines which are given include the following: alicyclic, phenalkyl furfuryl and tetrahydrofurfuryl primary amines, aliphatic primary amines having not more than ten carbon atoms, N-alkyl alicyclic secondary amines in which the alkyl group has not more than five carbon atoms, dialkyl alkylene diamines in which the alkyl and alkylene groups have not more than five carbon atoms each, N-alkyl phenalkyl secondary amines in which the alkyl group has not more than five carbon atoms, dialkyl amines having not more than eight carbon atoms, N - alkyl - tetrahydrofurfuryl secondary amines in which the alkyl group has not more than five carbon atoms, and polymethylene secondary amines in which the polymethylene chain may be interrupted by an oxygen atom.  Numerous examples of amines which fall into the above groups are mentioned.  These amines are reacted with a zinc salt of a dithiocarbamic acid derived from an amine having the formula <FORM:0484299/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, or R1 and R together 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, N - methyl - tetrahydro - alphafurfurylamine, di-(beta phenethyl) amine, morpholine, sym-ethylene diamine, pipecoline, and N-methyl ethylamine.  The reaction which appears to be one of simple addition is preferably conducted in aqueous suspension or solution, but other solvents such as alcohol, benzene, xylene, or gasoline may also be used.  In examples: (1) cyclohexylamine and zinc dimethyl-dithiocarbamate are heated together in aqueous solution; (2) mixed amyl primary amines are added to a gasoline suspension of zinc dimethyldithiocarbamate; (3) cyclohexylamine is added to a gasoline suspension of zinc pentamethylene dithiocarbamate, and the mixture heated for a short time under reflux.  Tables are furnished to show the efficiency of the accelerators of the present invention when incorporated in a standard rubber mix.  Specifications 405,099 and 423,308 are referred to.