Process for the preparation of poly(vinylphenol) from poly(acetoxystyrene) by acid catalyzed transesterification
CA 1339438 C · Owner: Hoechst Celanese Corporation · Inventors: Gupta, Balaram B.G.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Polymers of 4-vinylphenol are made by the acid catalyzed transesterification of polymers of 4-acetoxystyrene in an alcohol. The 4-vinylphenol polymers are useful as epoxy resins curing agents and as the phenolic base for epoxy resin per se. B:3.P-126
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 2, 1997. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 2, 2014.
- 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.