Process for the preparation of hydroxy-vinyl-aromatic polymers or copolymers by anionic or controlled radical polymerization
CA 2457946 A1 · Owner: Kunimoto, Kazuhiko · Inventors: Kunimoto, Kazuhiko; Nesvadba, Peter
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The instant invention relates to a process for the preparation of hydroxyvinyl-aromatic polymers in particular 4-hydroxystyrene polymers or copolymers by anionic or controlled radical polymerization of the respective monomer wherein the hydroxy functionality is blocked with a protective group which is subsequently removed in a hydrogenation process. The resulting (co)polymers have a narrow polydispersity and are useful for manufacturing photoresists.
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 September 2, 2002. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended September 2, 2022.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 2, 2024.
- 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.