Expired Canadian patentCanada
Thermally stable polyesters containing trans-4,4'- stilbenedicarboxylic acid
CA 2118323 C · Owner: Morris, John C. · Inventors: Morris, John C.
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Melt processable copolyesters having improved thermal stability are prepared from 1,4-butanediol minor amounts of, trans-4,4'-stilbenedicarboxylic acid and trans- or cis-1,4-cyclohexanedicarboxylic acid.
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 April 19, 1993 and granted July 20, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 19, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 19, 2015.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledApril 19, 1993
GrantedJuly 20, 1999
Term endedApril 19, 2013
Patent numberCA 2118323 C
Classification (IPC)C08G63/54 +2 more
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.