Silanized silica
CA 2203726 C · Owner: Karbe, Henning · Inventors: Jacobsen, Hauke; Hartmann, Werner; Hennig, Thomas
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides a silanized pyrogenically- produced silica with the following physico-chemical properties: Specific surface area m2/g 80 - 400 Primary particle size nm 7 - 40 Tamped density g/l 50 - 300 pH value 3 - 10 Carbon content % 0.1 - 15 DBP number % < 200. The invention also provides a method of producing the above silanized pyrogenically-produced silica comprising spraying pyrogenically-produced silica in a mixing container under intensive mixing first with water or dilute acid and then with hexamethyldisilazane mixing for 15 to 30 minutes, and tempering at a temperature of 100 to 400°C for a period of 1 to 6 h.
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 April 25, 1997 and granted August 7, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 25, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 25, 2019.
- 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.