Polymerisation of maleic anhydride
CA 2009850 C · Owner: Rideout, Jan · Inventors: Macquarrie, Duncan James; Rideout, Jan
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Polymaleic anhydride having a weight average molecular weight by gel permeation, chromatography of between 450 and 800 and a polydispersivity of between 1.0 and 1.15 is, produced by polymerising malefic anhydride using a peroxide initiator in an , amount not greater than 10 % by weight of the anhydride in a dilute solution in o-xylene , or a substituted o-xylene.
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 February 12, 1990 and granted April 4, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 12, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 12, 2012.
- 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.