Polyester fibers modified with carbodiimides and process for their preparation
CA 2025418 C · Owner: Hoechst Aktiengesellschaft · Inventors: Zeitler, Herbert; Kruger, Erhard; Wick, Gottfried
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Polyester fibers modified with carbodiimides and process for their preparation, Polyester fibers and filaments which contain carboxyl end groups closed off by reaction with carbodiimides wherein, - the closing off of the carboxyl end groups has predominantly been carried out by reaction with mono- and/or biscarbodiimides which the fibers and filaments still contain in the free form however in as, little an amount as less than 30 ppm (by weight) of the polyester, - the content of free carboxyl end groups is less than 3 meq/kg of polyester and, - the fibers and filaments still contain at least 0.05% by weight of at least one free polycarbodiimide or a reaction product which still contains …
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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 September 14, 1990 and granted November 28, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 14, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 14, 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.