Formation of optically anisotropic pitches
CA 1194445 A · Owner: E. I. Du Pont De Nemours And Company · Inventors: Venner, Joe G.; Diefendorf, Russell J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An improved process for preparing liquid crystal containing pitches includes extracting carbonaceous isotropic pitches with an organic solvent system which comprises at least one member of the group consisting of dioxane, dimethylacetamide and, tetramethylurea.
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 1, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 1, 2002.
- 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.