"Stractol" sulfur compound (insoluble sulfur)
It does not dissolve in rubber and does not migrate, so it does not cause blooming.
Insoluble sulfur is primarily used for rubber. Its advantage is that it does not dissolve in rubber and does not migrate, thus preventing the so-called blooming. At room temperature, the S8 cyclic molecules present in normal soluble sulfur open up when the temperature exceeds 158°C, causing sulfur chains to bond together and polymerize. By rapidly cooling this molten polymer chain, sulfur is transformed into an insoluble sulfur state that does not revert back to S8 cyclic molecules, resulting in a metastable polymer structure. This polymer chain is insoluble in organic solvents and rubber, and in rubber compounds, it remains suspended like an inactive filler. It softens to some extent with temperature and exhibits thermoplastic behavior. Most standard grades of insoluble sulfur consist of over 90% sulfur polymer and less than 10% soluble sulfur. However, due to its very fine particle size, it tends to clump together due to static electricity, making it difficult to disperse in rubber. Insoluble sulfur often clings around the nip during roll processing, which is believed to be due to its higher tendency to become charged with static electricity compared to normal soluble sulfur.
- Company：エスアンドエスジャパン
- Price：Other
