Precipitated calcium carbonate and its production and use
CA 2326989 A1 · Owner: Ecc International Inc. · Inventors: Perez, Ricardo; Jackson, William B.; Bryan, David P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of producing a precipitated calcium carbonate (pcc) product which has a coarse crystalline form which comprises the steps of: (a) preparing a suspension in an aqueous medium of calcium hydroxide particles which partially dissolve as calcium ions in the aqueous medium the aqueous medium also , incorporating an agent which promotes release into solution in the aqueous medium of calcium ions from the calcium hydroxide; (b) adding carbon dioxide to the aqueous medium to react with the calcium ions therein to produce a suspension in the aqueous medium of a precipitate of calcium carbonate crystals; (c) concentrating the suspension of the precipitate by a dewatering process; and …
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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 April 1, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 1, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 1, 2021.
- 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.