High strength porous film of polypropylene and process for producing same
CA 2203734 A1 · Owner: Mitsui Petrochemical Industries, Ltd. · Inventors: Yagi, Kazuo; Mantoku, Hitoshi; Hashimoto, Akinao
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Disclosed is a high strength porous film of polypropylene which comprises predominantly a polypropylene resin and possesses the following physical properties: (1) a tensile strength of at least 35 MPa in machine direction (MD) and transverse direction (TD); (2) a porosity of not more than 80%; and (3) a moisture permeability of at least 20 g/m2 day. The porous film may be produced by stretching or thermally treating a biaxially stretched polypropylene film. The high strength porous film may be used for wrapping food or as a separator of a secondary battery.
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 April 25, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 25, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 25, 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.