Polyester film for magnetic tape
CA 2062398 A1 · Owner: Watanuki, Yuko · Inventors: Utsumi, Shigeo; Inagaki, Masashi; Watanuki, Yuko
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A polyester film prepared through a lamination of at least two layers by coextrusion, wherein one of exposed surfaces (surface A) has a center line average roughness of from 0.002 to 0.015 µm, a polyester layer forming the other of the exposed surfaces (surface B) has a lower melting point than a polyester forming the surface A and the, surface B has a degree of planar orientation of not larger than 0.100, which can be used as a base film for magnetic recording tape having no back coating.
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 March 6, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 6, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 6, 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.