Tetrafluoroethylene copolymer fine powder resin
CA 1064647 A · Owner: E.I. Du Pont De Nemours And Company · Inventors: Poirier, Robert V.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Good extrusion at high reduction ratios is obtained with a non-melt-fabricable tetrafluoroethylene fine powder resin whose particles have an inner portion and an outer portion, each portion being composed of a copolymer of tetrafluoroethylene and a selected comonomer in which the como-, nomer content of the copolymer in the inner portion is greater than the comonomer content in the copolymer in the outer portion. Such particles are obtained by polymerizing tetrafluoroethylene and a desired amount of the selected comonomer in an aqueous dispersion medium then lowering, the amount of comonomer available and continuing the poly-, merization.
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
- Granted October 16, 1979. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 16, 1996.
- 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.