Insoluble sulfur is an important vulcanizing agent in tire processing and production. It is insoluble in carbon disulfide, and good insoluble sulfur is loose, non spherical, non flying, and has good thermal stability. It is used in the vulcanization process.
Insoluble sulfur has excellent adhesion when used for vulcanization of rubber materials. In the production of radial tires, it can better bond the meridian, steel wire, and rubber. Generally, after the crosslinking reaction rate and bonding reaction rate reach a balance, the adhesion between the rubber material and the skeleton material is better. Therefore, considering the time for the crosslinking reaction and bonding reaction of the rubber material, adjusting the type and dosage of sulfur and related accelerators, and coordinating the relationship between the two can help improve the adhesion of the rubber material. Secondly, the use of vulcanizing agents is crucial. Insoluble sulfur is beneficial for adhesion, and to ensure the performance of sulfur, attention should also be paid to its storage environment, mixing temperature, and storage temperature of mixed rubber.
Insoluble sulfur is made from solid sulfur as raw material. In chemical production, an extraction kettle is used to heat up chemicals such as carbon disulfide through steam, and then extract the sulfur that is insoluble in carbon disulfide. At the vulcanization temperature, the insoluble sulfur will transform into ordinary sulfur to exert its vulcanization effect on rubber. Therefore, its insolubility needs to be maintained before actual vulcanization application to avoid transforming into soluble ordinary sulfur that affects adhesion. Attention should be paid to controlling the storage temperature below 40 ℃. In areas where insoluble sulfur is stored, amine raw materials should not be stored at the same time, and the storage time should not be too long. The mixing temperature should not exceed 95 ℃.