Overview
Surface-treated for polar systems
VS17 is produced by reacting hydrophilic silica with active silanes (chlorosilane / HMDS types), chemically bonding the treatment to the particle surface. SiO₂ ≥95%, BET ≥160 m²/g, particle size 1–45 μm, bulk density 120–140 g/L. White powder, 10 kg paper bag.
Product Advantages
Why formulators choose it
- Low moisture absorption — performance holds in humid processing and storage
- Excellent dispersion, even in polar liquids such as epoxy resins
- Rheology adjustment capability in both polar and non-polar systems
- Structural modification available on top of hydrophobic treatment for custom development
- Improves dielectric properties and corrosion resistance of filled systems
How It Works
The principle
Untreated silica carries surface silanol groups that attract water, causing viscosity drift and caking. In VS17 those silanols are chemically capped with silane groups: the particle surface becomes permanently water-repellent while retaining its nano-structure. The result — stable thickening in polar resins, low moisture pickup, and reliable powder flow even at high humidity.
Applications
Application fields
Stable epoxy thickeningSilicone elastomer reinforcementHigh-loading molded productsAnticorrosion coatingsCable-compound dielectricsFree-flowing powder coatings & extinguishing agents
Recommended Grades
Find your grade
VS17
Silane-modified hydrophobic grade: heating loss ≤10%, ignition loss ≤8.5%, DBP >180 ml/100g, pH 6.5–8.5, Na₂SO₄ ≤0.4%, heavy metals (Pb) ≤0.003%.