Dicyclopentadiene alcohol rosin acid derivatives
CA 2076212 A1 · Owner: Sandstrom, Paul H. · Inventors: Sandstrom, Paul H.; Wideman, Lawson G.; Keith, Denise J.
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, dicyclopentadiene alcohol rosin acid derivatives which are useful as a rubber additive. In one embodiment the ester linked rosin acid derivative may serve as a total or partial replacement for oil and/or wax. The dicyclopentadiene alcohol rosin acid derivatives are prepared by reacting abietic acid and/or dehydroabietic acid with dicyclopentadiene alcohol under esterification conditions.
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 August 14, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 14, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 14, 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.