Carbon black replacement

Imerys minerals make cost-effective, environmentally friendly alternatives to carbon black.

Reduce carbon footprint and improve permeability 

Our minerals are cost-effective semi-reinforcing agents that can be used in partial substitution of more expensive carbon black where they improve the processability and permeability of rubber compounds and lower the overall carbon footprint of the end product.

Used as a partial substitution for, carbon black rubber compounds, our minerals:

  • Improve processability – lowering viscosity and improving mold flow and extrusion rates
  • Maintain mechanical properties such as elongation at break, modulus and cut/tear resistance
  • Reduce plasticizer evaporation, resulting in superior thermal and weather resistance
  • Reduce permeability by creating a barrier to the diffusion of gases
  • Improve the dispersion of carbon black
  • Reduce electrical conductivity


Microlamellar talcs, in particular, demonstrate a synergism with carbon black.

We particularly recommend our ImerFlex® range for synergism with carbon black in EPDM. ImerFlex talc can also be surface-treated with organofunctional silane coupling agents to improve filler/elastomer interaction. This interaction results in increased modulus and a significant improvement in the compression set.


Kaolins such as our Polestar™ and Glomax™ ranges are ideal for use in partial replacement of carbon black in color sensitive seals and gaskets where a superior compression set is required.

Suprex™ and Hexafil™ hydrous kaolins are minerals of choice for achieving good mechanical performance in hoses.


Wollastonites such as our Wollastocoat® grades are ideal for replacing carbon black in fluoroelastomer O-ring and gasket applications where they improve compression set and curing time.

*Talc products are not available in the USA and Canada. Contact us for an alternative range.