Butadiene monoepoxide/maleic anhydride copolymers
CA 2078552 C · Owner: Eastman Kodak Company · Inventors: Blevins, Richard W.; Turner, S. Richard
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Copolymers are produced when 3,4-epoxy-1-butene (EpB) is copolymerized with maleic anhydride. The copolymerization is initiated by free radicals, and comprises both 1,2-propagation and 1,5-propagation of EpB. When an ether is used as the reaction solvent, the product is soluble and essentially composed of (a) a monomer derived from maleic anhydride and (b) two, monomers derived from EpB. When the reaction solvent is a ketone the polymer product is also soluble, and additionally contains (c) a moiety derived from a dioxolane formed in situ. When the reaction is conducted in the presence of a non polar (e.g. hydrocarbon or a halocarbon) solvent or neat (i.e. in the absence of a solvent) the …
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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 March 14, 1991 and granted July 8, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 14, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 14, 2013.
- 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.