2-mercaptobenzothiazole

2-Mercaptobenzothiazole (CAS 149-30-4), commonly known as MBT or Captax, is a primary accelerator and intermediate used across rubber processing, industrial preservation, and specialty chemical synthesis. It activates sulfur vulcanization in elastomers and functions as a biocide and corrosion inhibitor in industrial fluid systems. In rubber and tire manufacturing, MBT accelerates sulfur crosslinking.

This improves cure efficiency and mechanical performance in finished goods for natural and synthetic elastomers. Industrial metalworking fluids and cooling water systems use it as a copper corrosion inhibitor. It forms a protective complex on metal surfaces to extend fluid service life. As a biocide, it controls microbial growth in cutting fluids, adhesives, and polymer dispersions where biological fouling occurs.

MBT also serves as a key synthesis intermediate for benzothiazole-based accelerator derivatives, including MBTS and CBS. These are produced at scale for the global rubber chemicals market. The product is supplied as a yellow to tan powder or as a sodium salt solution for fluid-system applications. Standard commercial grades include technical and rubber-grade specifications.

Purity typically ranges from 95% to 98% or higher depending on the specific application. Bulk supply is available in bags or drums, with technical-grade product being the dominant form traded.