Preparation of aromatic polyester with improved stability by addition of phosphite during preparation
CA 1310784 C · Owner: Celanese Corporation · Inventors: Pawlak, Joseph A.; Rosenfeld, Jerold C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for preparing an aromatic polyester derived from aromatic dicarboxylic acid and bisphenol includes adding a phosphite stabilizer to reduce coloration and reduce loss of intrinsic viscosity of the aromatic polyester to a molten mixture o the monomeric reactants or prepolymer.
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 November 24, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 24, 2009.
- 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.