Polymeric thickeners for aqueous compositions
CA 2264713 A1 · Owner: Shah, Dipak · Inventors: Grinstein, Reuben H.; Shah, Dipak; Wiggins, Michael
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process of preparing a concentrate which is useful as a thickener for aqueous compositions is provided. The process comprises obtaining a solution of an associative thickener compound in an organic solvent capable of forming a low boiling azeotrope with water. The solution is essentially free of water at this point and is at a temperature above the boiling point of said low boiling azeotrope. Water is added to said solution and an azeotrope of water and said organic solvent is distilled. The rate of addition of water is sufficient to replace said azeotrope with water but is insufficient to cause , a second phase to form in the resulting mixture of said solution and said water. 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 August 21, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended August 21, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 21, 2019.
- 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.