Thickened aqueous compositions
CA 2015193 C · Owner: Ciba Specialty Chemicals Water Treatments Limited · Inventors: Hawe, Malcolm; Farrar, David
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to aqueous acidic solutions which are thickened by cationic polymer the polymer, being added to the solution in the form of particles below 10µm in size. The useful cationic polymers are formed from a water soluble cationic ethylenically unsaturated monomer or blend of monomers that includes a polyethylenically unsaturated cross-linking agent. A peak viscosity is achieved in the aqueous acidic solution at a particular cross-linker concentration. The concentration of cross-linking agent chosen is carefully controlled so that the viscosifying effect can be optimised whilst minimising the amount of polymer that has to be added. The amount of polymer in the aqueous acidic …
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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 April 23, 1990 and granted January 18, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 23, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 23, 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.