Insoluble sulfur (IS) is mainly used in rubber products. Compared with ordinary sulfur, it has the following advantages:
1. The rubber material does not bloom during the storage period. Keep the rubber composition and performance uniform; overcome the shortcomings of poor rubber adhesion caused by blooming; prevent the contamination of products and molds and remove the added paste process to overcome blooming, providing conditions for production linkage .
2. There is no migration phenomenon in the adjacent glue layer. Especially in the rubber compound of butadiene rubber and butyl rubber, the migration speed of ordinary sulfur is very high, which can be avoided by adding insoluble sulfur.
3. Reduce scorch during mixing and storage.
4. Shorten the curing time. When the vulcanization temperature is reached, it has an "activation stage", that is, chain depolymerization, which speeds up the vulcanization speed and reduces the amount of sulfur, which is beneficial to the improvement of the aging performance of the product.
5. It is conducive to the adhesion of rubber and other materials. In special cases, it can be used together with S to improve the adhesion.
6. An indispensable additive in radial tires. In the production of radial tires, blooming can be effectively avoided, early vulcanization is not easy to occur, and the rubber material maintains good viscosity, which is conducive to the molding operation, and ensures the uniformity of vulcanization of the vulcanized rubber to ensure stable product quality.