Method for producing dual zone materials by catalyzed halosilylation
CA 2007819 C · Owner: Dow Corning Corporation · Inventors: Tangney, Thomas J.; Williams, Dwight E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Dual zone porous materials having an external zone and an internal zone are prepared by contacting a suspension of a porous support, such as particulate silica in a solvent, with a halosilane and a catalyst for the halosilane in order to form silyl groups of a first type predominantly on the external surfaces of the porous support. Preferably thereafter the porous support is contacted with a silane having silyl groups of a second type in order to form silyl groups of the second type predominantly on the internal surfaces.
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 January 16, 1990 and granted November 2, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 16, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 16, 2012.
- 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.