Production of high molecular weight polyhalobisphenol polycarbonates
CA 1322070 C · Owner: Kao, Che I. · Inventors: Kao, Che I.; Aguilar, Jose L.; Ho, Thoi H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to high molecular weight polyhalobisphenol polycarbonates which are produced by adding phosgene to a polyhalobisphenol in the alkali metal phenate form whereby the chloroformates of the bisphenol are formed and then adding an activated pyridine such as 4-aminoyridines or 2-substituted pyrldines to generate a high molecular weight palycarbonate having an inherent viscosity in the range from about 0.4 to about 0.9. These high molecular weight polycarbonates have high glass transition temperatures, good solvent and fire resistance and good hydrolytic stability. These polycarbonates are suitable for use in preparing hollow fibers for gas separations. 35,275-F
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 September 7, 1993. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 7, 2010.
- 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.