Cellulose acetate with trilobal cross section
CA 2296690 C · Owner: Koppe, Wolfgang · Inventors: Koppe, Wolfgang
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention relates to cellulose acetate filaments with trilobal cross section and with a degree of substitution of approximately 2.1 to 3Ø They have a filament titer of less than 3.3 dtex a PE form factor of less than , 0.320, and a PH form factor of less than 0.560. These cellulose acetate filaments have particularly advantageous absorptive qualities when used in cigarette filters.
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 July 15, 1998 and granted February 4, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 15, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 15, 2020.
- 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.