Sulfonium salts and use and preparation thereof
CA 2002425 C · Owner: International Business Machines Corporation · Inventors: Gelorme, Jeffrey D.; Kuczynski, Joseph P.; Lawrence, William H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Sulfonium salts of the formula:, wherein Ar is a fused aromatic radical; R1 is a divalent organic bridge; each R2 and R3 individually is an alkyl, aryl, alkaryl, aralkyl or substituted aryl provided that not more than one of R2 and R3 is alkyl; and A is a non-nucleophilic anion; use thereof and preparation thereof. The sulfonium salts are useful as photoinitiators and reduce the exposure requirement for photochemically induced cationic polymerization.
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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 November 7, 1989 and granted January 2, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 7, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 7, 2011.
- 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.