Method for the manufacture of thermoplastic resin sheets
CA 2013383 C · Owner: Takeshita, Sachio · Inventors: Tatsu, Saneharu; Takeshita, Sachio; Kiminami, Kazuhiro
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method for the manufacture of thermoplastic resin sheets comprising extruding molten thermoplastic resin at an extrusion velocity V through a slit provided in an extrusion mold so as to form thermoplastic resin sheets with embossed surfaces wherein said thermoplastic resin is extruded from said slit in said extrusion mold under conditions such that the ratio V/H of said extrusion velocity V to the width H of said slit exceeds a critical value (V/H)c said critical value (V/H)c being the ratio of the extrusion velocity to the width of the mold slit corresponding minimum value of the roughness of the embossment formed on the surface of said thermoplastic resin sheets, whereby defects such as …
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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
- Filed March 29, 1990 and granted October 25, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 29, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 29, 2012.
- 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.