Preparation of finely divided, gel-like, water-swellable copolymers
CA 2004331 A1 · Owner: Basf Aktiengesellschaft · Inventors: Hartmann, Heinrich; Wickel, Stefan; Heide, Wilfried
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
O.Z. 0050/4043, Abstract of the Disclosure: Finely divided gel-like, water-swellable copolymers are prepared by copolymerizing (a) 100 parts by weight of water-soluble monoethylen-, ically unsaturated monomers (b) from 0.01 to 5 parts by weight of monomers containing two or more ethylenically unsaturated double bonds and, (c) from 0 to 20 parts by weight of water-insoluble monoethylenically unsaturated monomers in 20-80% strength by weight aqueous solution in the presence of a polymerization initiator and from 0.1 to 10% by weight, based on the monomers used in the copolymerization, of a surfactant, by a process in which the monomers are copolymerized in the presence of initially from 0 to …
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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 November 30, 1989. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 30, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 30, 2011.
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Timeline
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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.