High surface area zirconia
CA 2043320 C · Owner: Shell Canada Limited · Inventors: Derking, Anke; Reinalda, Donald
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
High surface area zirconia, having a surface area after calcination, is obtainable by a process comprising aging zirconium hydroxide in the presence of an acid of an element of Group V or VI of the Periodic Table of Elements and calcining the zirconium material so-obtained. The preferred acid is phosphoric acid in, particular orthophosphoric acid. A high surface area zirconia is provided having a surface area of at least 180m2/g after calcination at a temperature of 300 °C.
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 May 27, 1991 and granted February 5, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 27, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 27, 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.