Product Description

Chemical name: Mixture of polymeric sulfur and silica

Crystex™ OT 33 AS is a non-blooming vulcanizing agent for unsaturated elastomers.


  • Crystex™ OT 33 AS is polymeric sulfur and is insoluble in elastomers. Consequently it will retard bin scorch, prevent migration of sulfur and preserve surface tack. This is important in the manufacture of tires and other plied-up rubber goods.
  • At vulcanization temperatures Crystex™ OT 33 AS will de-polymerize to soluble sulfur and will behave similar to "Rubber Maker's" sulfur.
  • Crystex™ OT 33 AS is a metastable product which can revert to soluble sulfur if not stored under proper conditions.
  • Reversion of Crystex™ OT 33 AS to soluble sulfur is also catalyzed by alkaline products. The presence of alkaline accelerators can be critical.
  • Crystex™ OT 33 AS is a special grade with high thermal stability and good dispersibility due to the presence of silica.
  • Crystex™ OT 33 AS is used in compounds containing a relatively large sulfur loading above the solubility of sulfur in the elastomer.
  • Crystex OT 33 AS is non-staining and non-discoloring.


  • Tires

Regulatory Information and Data Sheets

Product Availability

Check with local Sales Office to determine exact availability by country. Orders subjected to minimum order quantity.
  • Europe, Middle East & Africa

Authorized Distributors

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