Insoluble sulfur is widely used as an advanced accelerator and vulcanizing agent in the rubber industry in the production and manufacturing of tires and other rubber composite products, such as tire body rubber, buffer rubber, white tire side rubber, and rubber and skeleton materials bonded to rubber, rubber tubes, tape, etc. It can also be used in rubber products such as cables, rubber rollers, oil seals, rubber shoes, etc. It is also used in light colored rubber products with high sulfur content. Due to the insolubility of sulfur, it can make the meridian, steel wire and rubber bond more firmly, effectively prevent the rubber material from frosting, and improve the heat resistance and wear resistance of the tire. Therefore, insoluble sulfur is an essential and important raw material in tire production.
The use of sulfur as a vulcanizing agent is still widely used in the rubber industry. As a variant of sulfur (S) - insoluble sulfur (IS), it is widely used in the manufacturing of tires, rubber shoes, rubber hoses, tapes, and miscellaneous products both domestically and internationally, and has been widely used in the bonding of rubber and steel wires.
Insoluble sulfur (IS) is a linear long-chain polymer produced by deep processing of sulfur (S), with sulfur atoms on the molecular chain exceeding 108; Has high polymer viscoelasticity and molecular weight distribution; Insoluble in carbon disulfide, hence it is called insoluble sulfur. Insoluble sulfur (IS) is mainly used in rubber products and has the following advantages compared to ordinary sulfur:
1. The adhesive material shall not spray frost during its storage period. Maintain uniformity in the composition and properties of the adhesive material; Overcoming the disadvantage of poor adhesive strength caused by frost spraying; Prevent contamination of products and molds, and remove the coating process added to overcome frost spraying, providing conditions for production linkage.
2. There is no migration phenomenon in adjacent adhesive layers. Especially in the rubber materials of butadiene rubber and butyl rubber, the migration rate of ordinary sulfur is very high, which can be avoided by adding insoluble sulfur.
3. Reduce coking during mixing and storage.
4. Shorten vulcanization time. After reaching the vulcanization temperature, it has an activation stage, namely chain depolymerization, which accelerates the vulcanization rate and reduces the amount of sulfur used, which is beneficial for improving the aging performance of the product.
5. It is beneficial for the adhesion between rubber and other materials, and in special cases, it can be used in conjunction with S to improve adhesion.
6. An indispensable additive in radial tires. In the production of radial tires, it can effectively avoid frosting, prevent early vulcanization, and maintain good viscosity of the rubber material, which is conducive to molding operations and ensures the uniformity of vulcanization, ensuring stable product quality.