Cellulose acetate filaments, an optically isotropic spinning solution therefor, and use thereof for the production of filaments
CA 2113142 A1 · Owner: Koppe, Wolfgang · Inventors: Koppe, Wolfgang; Schatzle, Joachim; Karstens, Ties
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
There are described filaments on the basis of a cellulose acetate soluble in acetone, the degree of polymerization (DP) of the cellulose acetate being between about 110 and 210 and the degree of substitution (DS) preferably between about 2.2 and 2.7. Optically isotropic spinning solutions can be obtained, the cellulose acetate concentration of which is about 35 to 47 mass-%. When such an optically isotropic spinning solution is spun, in particular by dry spinning filaments are obtained in a profitable manner because the costs connected with the recovery of the acetone can be appreciably lowered, without impairing the desirable properties of the filaments, which are suitable in particular …
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 January 10, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 10, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 10, 2016.
- 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.