Polyethylene terephthalate film for magnetic recording medium
CA 2061545 A1 · Owner: Meguro, Yoshio · Inventors: Harada, Takashi; Kawaguchi, Chikakazu; Meguro, Yoshio
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Disclosed herein is a polyethylene terephthalate film for magnetic recording medium, which contains 0.1 to 1.0 % by weight based on the film of aggregated silicon oxide particles having an average particle size of 0.03 to 0.2 µm primary particle of, which having an average particle size of 0.005 to 0.05 µm 0.1, to 1.0 % by weight based on the film of aggregated aluminium oxide particles having an average particle size of 0.03 to 0.2 µm, primary particle of which having an average particle size of 0.005 to 0.05 µm and 0.005 to 0.3 % by weight based on the film of a crosslinked polymer having an average particle size of 0.2 to 0.8 µm, said film having a center line average surface roughness …
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 February 19, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended February 19, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 19, 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.