Polypropylene sheet for press-through packages, production process thereof, and polypropylene resin composition
CA 1293575 C · Owner: Usami, Katsuyuki · Inventors: Ueki, Toru; Sentoku, Hajime; Kanezaki, Kazuharu
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract, Disclosed herein is a polypropylene sheet obtained by forming a resin composition which contains, a polypropylene resin and a hydrogenated petroleum resin in specific amounts, into a sheet at a particular chill-roll temperature and then annealing the sheet at a specific temperature for a specific period of time as well as an improved production process of such a polypropylene sheet. Also disclosed is a polypropylene sheet comprising a sheet obtained from the above resin composition and a polypropylene layer of at least 10 µm thick applied on at least one side of the sheet. A polypropylene resin composition suitable for the production of such polypropylene sheets is also disclosed. …
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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
- Granted December 24, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 24, 2008.
- 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.