Find optimal solutions for your requirements

Whether for individual rheological properties, reinforcement, or thickening, HDK® Hydrophobic Fumed Silica achieves remarkable results.

Fumed silica provides performance advantages in many ways:

  • Reinforcement - improving strength in silicones and other polymers
  • Rheology control
    • Thickening - tailored flow properties
    • Sag resistance - reduced sag of liquids and pastes
    • Anti-settling - prevents sedimentation and settling
    • Thixotropy - shear thinning viscosity profiles
  • Free flow additive in powders

Choose any of the products below to download the PDS or complete the short form and a member of the Brenntag North America team will contact you shortly. 

Product Hydrophobicity Treatment Hydrophobic BET Surface Area1 Characteristics & Typical Applications

HDK® H21


Very High Siloxane 110

Designed to provide unsurpassed thickening, highly efficient processing, prolonged storage stability, and superior sag resistance

Used in highly polar systems including epoxy resins, isocyanate prepolymers, vinyl ester resins, and polar solvent-based formulations

HDK® H18 Very High Siloxane 120

Excellent for rheology control in highly polar systems, outstanding for non-sag epoxy & urethane adhesives and sealants

Used in highly polar adhesives and sealants, composite materials, and solvent-less systems

HDK® H17 Very High Siloxane 90

Designed for optimal processing. Good rheology control in polar systems needing the easiest dispersibility

Used in composites, coatings, adhesives and sealants

HDK® H13L High Silane 110

Excellent dispersibility, capable of high loadings in non-polar systems for reinforcement, good rheology control in moderately polar systems

Used in coatings, printing inks, adhesives, and others. Well suited for solvent-free systems, for high solids and for waterborne coatings

HDK® H20 Medium Silane 170

Enables free flow in powder coatings, grinding & processing aid in powder coatings

Good rheology control in moderately polar sealants and adhesives, dispersions, and aqueous polymer solutions

HDK® H15 Medium Silane 120

Capable of high loadings in non-polar systems for reinforcement, good rheology control in moderately polar systems

Used in moderately polar sealants and adhesives, RTV systems, solvent-based and solvent-less systems

1approx. (m2/g)3 DIN ISO 9277 DIN 66132