Method for preparing hollow latexes
CA 2025633 C · Owner: Cohrs, William E. · Inventors: Chonde, Yohannes; Cohrs, William E.; Mcdonald, Charles J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides for a process for preparing hollow polymer latexes. A first charge of a organic phase is introduced to an aqueous phase. The first charge of the organic phase comprises monomer which is virtually insoluble in the aqueous phase and, an inert-nonpolymerizable hydrocarbon. The polymer formed from polymerizing the monomer is virtually insoluble in the hydrocarbon, the hydrocarbon is virtually insoluble in the aqueous phase and the monomer is miscible with the hydrocarbon. The monomer is polymerized to produce a low molecular weight polymer which phase separates from the organic phase and concentrates at the surface of the organic phase forming a low molecular …
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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 September 18, 1990 and granted October 2, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 18, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 18, 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.