Organo-metallic compounds
CA 2002792 C · Owner: Tioxide Group Plc · Inventors: Brown, David Alexander; Ridland, John
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An organometallic compound which is the reaction product of (a) a zirconium halide or oxyhalide, (b) a polyol and (c) an alpha-hydroxy acid is claimed. The preferred polyol is sorbitol and preferred alphahydroxy acids are citric, malic or lactic acid. The compounds find use as cross-linking agents in fracturing fluids employed in the hydraulic fracturing of oil or gas-containing subterranean strata. The claimed compounds can be used to produce a slow or delayed gel formation in such fluids.
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 November 10, 1989 and granted April 1, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 10, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 10, 2011.
- 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.