Rubber vulcanization system containing bis-(2,5-polythio-1,3,4-thiadiazole), bismaleimide and sulfenamide

A rubber vulcanization composition comprising:

• (a) from about 2 to about 15 weight percent of bis- (2,5-polythio-1,3,4-thiadiazole) consisting of the formula:
• ##STR10## wherein the sum of x and y is from 1 to 16 and x and y are independently selected from 0 and integers of from 1 to 8;
• (b) from about 15 to about 50 weight percent of a bismaleimide compound of the general formula:
• ##STR11## wherein R is divalent and is selected from the group consisting of acyclic aliphatic groups having from about 2 to 16 carbon atoms, cyclic aliphatic groups having from about 5 to 20 carbon atom, aromatic group having from about 6 to 18 carbon atoms, and alkylaromatic groups having from about 7 to 24 carbon atoms and wherein these divalent groups may contain a hetero atom selected from 0, N and S;
• (c) from about 15 to about 45 weight percent of a sulfenamide compound of the general formula:
• ##STR12## wherein R.sup.1 is selected from the group consisting of hydrogen, acyclic aliphatic groups having from about 1 to 10 carbon atoms, and cyclic aliphatic groups having from about 5 to 10 carbon atoms;
• and R.sup.2 is selected from the group consisting of cyclic aliphatic groups having from about 5 to 10 carbon atoms and mercaptobenzothiazolyl groups of the formula:
• ##STR13## and (d) from about 20 to about 55 weight percent of sulfur, a sulfur donor and mixtures thereof.