CE Products

Hydrophobic Fumed Silica TD-20


CE Chemicals Hydrophobic Fumed Silica TD-20 is used in coatings, sealants, adhesives, elastomers, and polymers as an efficient rheology modifier, thickener, and reinforcement filler.

General Information

CAS: 68611-44-9

Synonyms: Pyrogenic silica; Silica fume; Fumed colloidal silica; Silica, fumed; silicic amorphous silica; colloidal silicon dioxide

Counter Type: Evonik R974


Fumed Silica TD-20 is fumed hydrophobic silica treated with DDS.


  • Paints and Coatings
  • Silicone rubber
  • Adhesives and Sealants


  • Hydrophobic component for thickening and reinforcement of silicone sealants and improving their shelf life.
  • Rheology control of liquid systems.
  • For use in coatings as an anti-settling agent, for pigment stabilization and improvement of corrosion protection.
  • Reducing caking and improving the flowability of fine powders.





Specific surface area(BET)



Loss on drying, 2h at 105



C content



Tamped density



pH value



SiO2 content



Packaging, Storage & Transportation

Packed in 10 kg kraft paper bags then secured with pallet, 200kg/pallet.

Keep in sealed containers in a dry, cool place.

Shelf Life

2 years

Product Overview

The manufacturing process of Hydrophobic Fumed Silica TD-20 begins with the vaporization of silicon tetrachloride (SiCl₄) in an oxygen-free atmosphere. This produces a high purity of silicon dioxide. The resulting vapor is then hydrolyzed and condensed to form fumed silica. Hydrophobic Fumed Silica TD-20 is highly dispersible, making it an ideal additive for coatings, sealants, adhesives, elastomers, and plastics. Hydrophobic Fumed Silica TD-20 is obtained from fumed silica with a specific surface area of 200, treated with Dichlorodimethylsilane (DDS) hydrophobic treatment.

Chemical properties of CE Chemicals Hydrophobic Fumed Silica TD-20:

  • Hydrophobic: treated with a surfactant to make the surface water repellent.
  • Fumed: produced by flame hydrolysis of silicon tetrachloride (SiCl₄) in an oxygen-free atmosphere.
  • TD-20: primary particle size of 12nm

    The applications of CE Chemicals Hydrophobic Fumed Silica TD-20 include:

    • Rheology modifier: thickener and reinforcing filler
    • Coating: improve suspension, leveling, thixotropy, and resistance to sagging or running
    • Sealant: improve flowability, thixotropy, and durability
    • Adhesive: improve flowability, thixotropy, and adhesion to difficult substrates
    • Elastomer: improve compression set, abrasion resistance, and tear strength
    • Plastic: improve stiffness, dimensional stability, and surface finish.

    Scratch Resistance & Hardness

    Fumed silica raises the resistance of cured paints to mechanical stress. Its particles prevent scratching on a coating’s surface and improve its ability to radiate energy without causing major cracks.

      Sag Resistance

      Fumed silica particles are very effective in this domain due to their ability to network and span volume. In general, the thicker coating requires greater sag resistance.

        Anti-Settling Properties

        Due to its fume capacity, fumed silica prevents heavy pigment particles from settling in the coating. It forms a network within the layer in order to retain them.

          Corrosion Resistance

          Fumed silica improves the corrosion-preventive capability of a coating. The use of hydrophobic fumed silica particles aids in the prevention of water movement from the film’s surface to the substrate beneath it.

          Water, air, and an electrolyte cause aluminum substrates to corrode. The coating peels away from the substrate as a consequence of this reaction. Fumed silica prevents moisture from reaching the substrate, reducing blistering.

          If you have any questions about CE Chemicals Hydrophobic Fumed Silica TD-20, or if you would like to request a sample, please contact us. Our experts will be happy to assist you.

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