Method for manufacture of polymers
CA 2127526 C · Owner: National Starch & Chemical Ltd. · Inventors: Kimpton, Paul T.; Lagar, Philip A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for the polymerization of polymers of itaconic acid and vinyl acetate comprising the step of polymerizing (i) from 10 to 95 mole percent of monomer units of the formula I: (see fig. I), wherein each of R1 and R2 which may be the same or different, represents a hydrogen atom a methyl group or an ethyl group, and M is a hydrogen atom or an alkyl (C1 to C18) chain or an organic group such as an amino containing functionality; (ii) from 5 to 90 mole percent of monomer units of the formula II: (see fig. II), wherein R3 represents a hydrogen atom or the group -COCH3; and (iii) from 0 to 45 mole percent of a ethylenically unsaturated copolymerizable comonomer, said polymerization being …
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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 July 6, 1994 and granted November 24, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 6, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 6, 2016.
- 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.