| abstract |
A heat curable composition comprises (1) polyethylene, (2) an organic peroxide in an amount sufficient to promote cross-linking of said polyethylene on heating, and (3) an organic cross-linking regulator which is a metal salt having the general formula MXs wherein M is a polyvalent metal which is zinc, lead, copper, bismuth, tellurium or selenium; s is an integer having a value equal to the valence of the metal and is at least 2; and X is (a) a benzothiazol-2-ylthio group; (b) an N,N-substituted dithiocarbamoyl sulphide group of the formula <FORM:1060357/C3/1> wherein R10 and R11, when taken alone, are alkyl of from 1 to 7 carbons or benzyl, and R10 and R11, when taken together, form the divalent pentamethylene group; or (c) an alkyl-xanthoyl radical having the general formula <FORM:1060357/C3/2> wherein R14 is alkyl or from 1 to 4 carbons. Other compounding ingredients are carbon black and 2,6-di-tert.-butyl-paracresol. |