Porous laminar pellets of waste poly (ethylene terephthalate) film, and processes for drying and polymerization
CA 1089616 A · Owner: E.I. Du Pont De Nemours And Company · Inventors: Hoffman, Frank E.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Porous laminar pellets of comminuted crystalline poly(ethylene terephthalate) waste film are formed. The pellets do not contain a binder, but are coherent since the polymer flakes making up the pellets are mechanically interlocked or interwined. Rapid drying and solid state polymerization rates are achieved, and the pellets have sufficient structural integrity to survive such processes but may be readily disintegrated upon completion of such processes if so desired. The pellets are also well adapted for dissolution, such as in glycol monomer for glycolysis and in molten polymer.
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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 November 18, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 18, 1997.
- 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.