Polyvalent metal salts of salicylic acid resin and process for the preparation thereof
CA 2300773 A1 · Owner: Lee, Sung Woo · Inventors: Lee, Sung Woo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to a process for preparing polyvalent metal salts of salicylic acid resin, comprising reacting salicylic acid or its derivative and styrene or its derivative in the presence of zinc salt of organic carboxylic acid and/or polyvalent metal compound at 50 to 200 °C, to prepare the reaction product, and reacting the reaction product with polyvalent metal compound; an aqueous dispersion where the polyvalent metal salt of resin is dispersed in water; and to a color development sheet prepared from the polyvalent metal salts of salicylic acid resin.
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 March 17, 2000. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended March 17, 2020.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 17, 2022.
- 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.