Polypropylene resin foamed sheet for thermoforming and process for producing the same
CA 1295448 C · Owner: Sekisui Kaseihin Kogyo Kabushiki Kaisha · Inventors: Matsuoka, Kiyotaka; Doi, Tsuneo; Hayashi, Motoshige
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A polypropylene resin foamed sheet for thermoforming having compounded therein an inorganic fine powder is disclosed. The sheet contains 10 to 50% by weight of the inorganic fine powder has a density, of 0.2 to 1.2 g/cm and a thickness of 0.2 to 3 mm and having a percent shrinkage of 5 to 30% in each of the longitudinal and crosswise directions on heating at 190°C for 30 minutes, with the ratio of a residual rate in the longitudinal direction to that in the crosswise direction being from 1:07 to 1:1.1. The sheet is produced by extruding and foaming a compounded resin from a ring die of an extruder and, taking off the extruded tubular foamed sheet along a cylindrical plug whose diameter is …
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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 February 11, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 11, 2009.
- 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.