Method of the Preparation of Vulcanization Mixtures by the De-Vulcanization of Waste Rubber

摘要

Waste rubber in the from of crumbs, mainly from automobile tires, but also from other used rubber products including waste rubber formed in the course of their manufacturing, is mixed in a kneader, calender, or extruder with a compound containing the chemical group -SO₂-NH-. Subsequently, at temperatures up to 180° C. the rubber crumbs are de-vulcanized within 15-20 minutes, the de-vulcanization degree being controlled by the de-vulcanization agent concentration, and time and temperature of de-vulcanization. After the eventual addition of small amounts of extenders as oil, soot, raw rubber, inorganic filler and the vulcanization agent a vulcanization mixture is obtained that after pressing into the shape of the rubber product is subjected to a standard vulcanization process.