WACKER® SILICATE TES 40 WN is an ethyl silicate polymer.  It is a low-viscous liquid providing approximately 41% of silicon dioxide (silica) upon complete hydrolysis. 



WACKER® SILICATE TES 40 WNoffers these properties

  • storage-stable, low-viscous liquid with a high silica content (41% SiO2, after full hydrolysis/dehydration)
  • high flash point > 62°C
  • reactive binder after alkaline or acid-catalyzed hydrolysis for many applications
  • actual binder are polymeric SiO2-structures formed by hydrolysis and condensation reactions


WACKER® SILICATE TES 40 WNis being used for the precipitation of silica (polymeric SiO2 structures) upon complete hydrolysis. The hydrolysis creates ethanol as a by-product.

The polymeric SiO2 structures firmly bind inorganic fillers and pigments and adhere well to different inorganic substrates like glass, ceramics or metall. Chemical and mechanical properties of the substrates can be improved by the thin SiO2 film, which is also highly heat-resistant.


Application examples

  • binder for zinc-rich anti-corrosive coatings, e .g. shop primers
  • binder for refractory fillers (production of ceramic shells and cores)
  • precision casting
  • coating material for pigments and fibers
  • liquid source of SiO2 as binder
  • crosslinking agent, e.g. for silicone elastomers
  • sol-gel processes


Use as binder for two-pack zinc-rich ethyl silicate primers

Hydrolysis of WACKER® SILICATE TES 40 WN induced by atmospheric humidity is too slow for typical moisture-curing coating applications like shop primers. The ethoxy groups must be activated by further chemical hydrolysis. This is typically done in a chemcial reactor by the addition of water and an acid catalyst in a water-miscible co-solvent. Condensation and formation of larger polymeric molecules already start during hydrolysis. The hydrolysate is the actual binder for the zinc-rich shop primer. Shelf-life of the hydrolysate is limited because the condensation slowly proceeds upon storage.


  • 25 kg steel can
  • 215 kg steel drum
  • 1000 kg IBC


WACKER® SILICATE TES 40 WNmust be stored in the tightly closed original container under exclusion of moisture.

The "Best use before end" date of each batch is shown on the product label.

Storage beyond the date specified on the label does not necessarily mean that the product is no longer usable. In this case however, the properties required for the intended use must be checked for quality assurance reasons.

Sales and support

Wacker Chemical Corporation
3301 Sutton Road
Adrian, MI 49221-9397
United States
+1  888  922-5374 (Phone)

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