Iron oxide particles and process for producing the same
CA 2107524 C · Owner: Toda Kogyo Corporation · Inventors: Misawa, Hiromitsu; Kozawa, Minoru; Okano, Yoji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Disclosed herein is iron oxide particles comprising: 100 parts by weight of material iron oxide particles having a specific surface area represented by the following formula (1):, 6/(p~d3) x ~s (1), wherein p represents a specific gravity of said iron oxide particles, d3 represents an area-average particle diameter (0.1 µm ~ d3 ~ 1.0 µm) and ~s represents an area shape factor) (1.0 ~ ~s ~ 2.0); and, 0.25 to 10 parts by weight (calculated as an oxide) of the fine particles of the oxygen compound the fine particles, of the hydrate or mixed fine particles thereof of one element selected from the group consisting of Al Si, Zr and Ti, which, are adhered to the surfaces of said iron oxide …
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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 October 1, 1993 and granted January 19, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 1, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 1, 2015.
- 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.