Process for producing ultrafine particles of colloidal calcium carbonate
CA 2196123 C · Owner: You, Kyu Jae · Inventors: You, Kyu Jae
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for producing ultrafine particles of colloidal calcium carbonate whichcomprises the steps of adding magnesium sulfate into an aqueous suspension of calcium hydroxide, carbonating the aqueous suspension by introducing carbon dioxide into the aqueous suspension, and adding zinc sulfate alone or together with sulfuric acid into the aqueous suspension simultaneously with the carbonation step. Ultrafine particles of colloidal calcium carbonate in a chain-structured configuration which have an average diameter of 0.01 µm or smaller an average, length of 0.05 µm or longer and a BET surface area of 70 m~/g or greater areproduced.
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 28, 1997 and granted May 30, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 28, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 28, 2019.
- 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.