Process of using an improved flue in a titanium dioxide process
CA 2008192 C · Owner: E. I. Du Pont De Nemours And Company · Inventors: Gonzalez, Raul A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In the process for producing titanium, dioxide by (a) reacting titanium tetrachloride and oxygen in the vapor phase to produce titanium dioxide, and, (b) subsequently cooling the titanium dioxide in a flue, an improvement comprising utilizing for all or a portion of the flue a conduit having a plurality of internal, substantially longitudinal protuberances depressions or both.
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 19, 1990 and granted February 23, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 19, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 19, 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.