Mixtures of spiroheptadienes
CA 2068833 A1 · Owner: Scharf, Wolfgang · Inventors: Pasquier, Cecile; Zahir, Sheik A.; Dupre, Maurice
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Mixtures essentially comprising compounds of formula I or II wherein X is a hydrogen atom or vinyl, A is a divalent aromatic radical which is, unsubstituted or substituted by one or more C1-C20alkyl groups halogen atoms , or, halogen-substituted C1-C20alkyl groups R1, R1', R2', R3', R3 and R3' are each a hydrogen, atom, or R1 and R1', R2 and R2'and R3 and R3' arc each together ethylene R4 , is, C1-C6alkyl, phenylalkyl containing 1 to 6 carbon atoms in the alkyl moiety or is, trialkylsilyl containing 1 to 6 carbon atoms in each alkyl moiety m is 0, 1 , or 2, n is 0 or an, average number from 1 to 200 p is an average number from 1 to 100 and q is 0 or an, average number from 1 to 100, can …
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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 May 15, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 15, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 15, 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.