amount of sulfur vulcanizing agent in the vulcanization system of the present invention ranges from about 20 to about 55 weight percent preferably the sulfur vulcanizing agent ranges from about 23 to 43 weight percent when the vulcanization system of the present invention is added to a rubber stock the sulfur vulcanizing agent is present in an amount ranging from about 0 5 to about 6 phr preferably the sulfur vulcanizing agent is present in an amount ranging from about 0 75 phr to about 2 0 phr conventional rubber additives may be incorporated in the rubber stock of the present invention the additives commonly used in rubber stocks include fillers plasticizers waxes processing oils retarders antiozonants antioxidants and the like the total amount of filler that may be used may range from about 30 to about 150 phr with a range of from about 45 to about 70 phr being preferred fillers include silicas clays calcium carbonate calcium silicate titanium dioxide and carbon black haf black n 330 and gpf black n 660 are commonly used in rubber stocks intended for use as wire coats or carcass ply coats preferably at least a portion of the filler is carbon black plasticizers are conventionally used in amounts ranging from about 2 to about 50 phr with a range of about 5 to about 30 phr being preferred the amount of plasticizer used will depend upon the softening effect desired examples of suitable plasticizers include aromatic extract oils petroleum softeners including asphaltenes hydrogenated esters of rosin acid pentachlorophenol.