Blended hydraulic cement
CA 2229491 C · Owner: Styron, Robert William · Inventors: Styron, Robert William
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention is directed to blended hydraulic cement compositions which are formed with subbituminous fly ash. In one embodiment the cement, composition comprises from about 0.1 wt. % to about 7 wt. % of a retarding agent; from about 0.1 wt. % to about 4 wt. % potassium carbonate; from about 0.1 wt. % to about 4 wt. % citric acid; from about 0.1 wt. % to about 5 wt. % lithium carbonate; and from about 85 wt. % to about 99.7 wt. % of a subbituminous fly ash. In another embodiment the cement composition, comprises from about 0.1 wt. % to about 7 wt % of a retarding agent; from about 0.1 wt. % to about 6 wt. % of an alkali source selected from the group consisting of potassium …
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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 February 11, 1998 and granted August 26, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 11, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 11, 2020.
- 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.