Precipitated silica
CA 2058404 A1 · Owner: Meier, Karl · Inventors: Esch, Heinz; Chojnowski, Marian; Nagel, Werner
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A precipitated silica paste is produced by dispersion of precipitated silica in silicone oil. In the hydrophobicization of precipitated silicas, the precipitated silica paste is used in suspension as the hydrophobicizing agent. The product is spraydried, conditioned and ground.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed December 23, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 23, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 23, 2013.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.