Dense polytetrafluoroethylene articles and a process for producing them
CA 2118116 C · Owner: Knox, John B. · Inventors: Connelly, John M. Jr.; Delaney, William Ellis, Iii; Knox, John B.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention provides a densified previously expanded PTFE article having remnants of a fibril and node structure and a process for producing the article. A PTFE shape is compressed through the application of heat and pressure while the shape itself is under a vacuum, thus forming the densified ePTFE article. The densified PTFE article exhibits increased flexural strength. A diaphragm containing the densified ePTFE article as one layer is also disclosed.
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
- Filed December 14, 1992 and granted March 30, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 14, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 14, 2014.
- 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.