High strength papers from floc and fibrids
CA 2037232 C · Owner: E. I. Du Pont De Nemours And Company · Inventors: Hendren, Gary L.; Ghorashi, Hamid M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Fibrid-floc papers yield unexpected improvements in strength when made from a combination of carbon, aramid, or glass fibers and fibrids consisting essentially of, where n is 4 or 5; X is from 0.01 to 0.50; and Ar is a radical selected from 3,4'-, oxydiphenylene, 1,3-phenylene, 1-methyl-2,4-phenylene and mixtures of such , radicals, with each other or with up to equimolar amounts of 1,4-phenylene radicals.
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 February 27, 1991 and granted January 29, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 27, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 27, 2013.
- 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.