Method for making an alkali-soluble emulsion copolymer
CA 2122977 A1 · Owner: Lorah, Dennis P. · Inventors: Madle, Thomas G.; Lorah, Dennis P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
of the Invention, An emulsion polymerization process for making a low molecular weight alkalisoluble copolymer of a water insoluble monoethylenically unsaturated aromatic monomer and methacrylic acid, includes heating an aqueous reaction mixture saidreaction mixture having a pH of less than or equal to about 4.5 and including from about 25 parts by weight to about 75 parts by weight of the water insoluble monoethylenically unsaturated aromatic monomer; from about 25 parts by weight toabout 75 parts by weight methacrylic acid; a polymerization initiator; a reducing agent; a catalyst effective for promoting decomposition of the polymerization initiator in the presence of the reducing agent; …
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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 5, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 5, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 5, 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
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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.