Sulphonated hydrocracking residues as concrete admixtures
CA 2173284 C · Owner: Houde, Jean, Jr. · Inventors: Clelland, Ian F.; Sawatzky, Henry; Farnand, Brian A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process is described for preparing a water-soluble sulphonated dispersant from a petroleum hydrocracking residue comprising: contacting a petroleum hydrocracking residue boiling above 524°C with concentrated sulphuric acid oleum or, sulphur trioxide to form a sulphonated mixture containing water soluble and water insoluble products and separating the, water soluble sulphonated product from the mixture. The mixture of water soluble and water insoluble sulphonated products is neutralized with alkali and evaporated to dryness after which the dried mixture is extracted with alcohol to leave a water soluble product. The product can be used as a water reducer or superplasticizer in concrete.
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 April 2, 1996 and granted August 10, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 2, 2016.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 2, 2018.
- 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.