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High-performance fillers for thermoset applications

Applications generallyConstructionConstruction chemistryCSH applicationsPaints and coatingsHealthFoundriesGlassCeramicsPaperGrinding and Polishing

High-performance fillers play a prominent role in the production of thermosetting plastics. The high demands made of the many types of thermosets, such as high strengths and high degrees of thermal stability, can be met only by functional fillers. In addition, their use in precast parts results in visually sophisticated, resistant surfaces.

Epoxy resin applications

On account of their good adhesion, good thermal stability, chemical resistance and excellent electrical properties, epoxy resins have been important for decades for electrical engineering and electronics.

In electronics, epoxy resin moulding materials are used as jacketing systems, laminating resins for circuits and auxiliary materials for PCB fabrication. In electrical engineering, epoxy resins are used in converter construction and for the fabrication of insulators and dry-type transformers.

The requisite mechanical, thermal and electrical characteristics of epoxy resin are determined largely by the functional filler selected. Fillers based on quartz, fused silica, wollastonite, mica, aluminium hydroxide and special fused alumina are used.


The high-performance fillers SILBOND® silanized micronized quartz powder and MILLISIL® quartz powder have proven themselves in epoxy resin systems over several decades. On the one hand they are used on account of their outstanding mechanical properties and on the other they make an important economic contribution. High-performance fillers based on quartz are characterized by the following properties:

  • High weather resistance and chemical resistance
  • High mechanical strengths
  • Good filler contents
  • Excellent processability
  • Low thermal expansion

On account of the excellent incorporation of surface-modified quartz powder (SILBOND® W 12 EST) into the epoxy polymer system, this has been the standard for weather-resistant outdoor applications for a long time. Nowadays SILBOND® quartz powder is also increasingly being used for 'indoor cast resin parts', among other things for visually glossy high-grade product surfaces.


A further development of the established silanized quartz powders SILBOND® W 12 EST is SILBOND® 126 EST, which offers an increase in the filler content with constant viscosity.

TREMIN® wollastonite for crack-sensitive applications

Blocky and acicular TREMIN® wollastonite is characterized by good electrical properties, low thermal expansion and very good reinforcing properties.

MICA, TREMICA® muscovite and TREFIL® phlogopite (mica)

Lamellar mica is characterized by good electrical insulating properties, very high breakdown strength and very good thermal stability.

SEPASIL® aluminium oxide for epoxy

The outstanding feature of aluminium oxide is its resistance to hydrofluoric acid. In addition, the material is characterized by good electrical properties, very good thermal conductivity and a high degree of whiteness.

PUR-RRIM applications: TREMIN® 939 wollastonite

Long-needled wollastonite TREMIN® 939 offers decisive advantages in PU RRIM:

  • High tensile strengths
  • High scratch resistance
  • Very good high-gloss paintability

Phenolic resin applications for brake linings:

Through the use of the functional fillers TREMIN® wollastonite, MICA muscovite, TREFIL® phlogopite, Chinafill kaolin, MILLISIL® quartz powder, SIKRON® micronized quartz powder and SILBOND® silanized micronized quartz powder, the following advantages can be achieved in phenolic resin applications for brake linings:

  • Reduced wear
  • Lower noise generation 
  • Lower degree of vibration
  • Better braking stability 
  • Uniform abrasion (low coefficient of friction behaviour)
  • Mechanical consolidation, in particular of the green bodies

Are you interested in a use in your company? If so, speak to us about it. We'll be glad to answer your questions!