Hexagonal magnetic ferrite pigment for high density magnetic recording applications
CA 2115669 A1 · Owner: Roden, John S. · Inventors: Sapieszko, Ronald S.; Dierssen, Gunther H.; Hopstock, David M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides a hexagonal magnetic ferrite pigment suitable for high density magnetic applications. The pigment is characterized by small particles size a modified, magnetoplumbite structure, and relatively high magnetic moment. The pigment is capable of being prepared by firing suitable precursor particles in air at temperatures below 850 ·C.
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 August 10, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 10, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 10, 2014.
- 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.