Water soluble nonionic cellulose ethers and their use in paints
CA 2011848 C · Owner: Ingvarsson, Ingemar · Inventors: Bostrom, Peter; Ingvarsson, Ingemar; Sundberg, Kenneth
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Water soluble nonionic cellulose ethers are provided containing mixed alkylphenoxyalkyleneoxy-2-hydroxy propylene groups, having hydrophilic units composed of (a) alkyleneoxy groups of two or three carbon atoms in a number from zero to about six, selected from -CH2CH2O-; -CH2CH-O-; and -CH2CH2CH2O-; and (b) one 2-hydroxy propylene ?, CH3, group, together with hydrophobic units which are alkylphenoxy groups of the formula, I, where R and R4 are hydrocarbon groups having from about four to about thirty carbon atoms, preferably from about nine to about eighteen carbon atoms; n1 is 0 or 1; connected linearly in a group of the general formula:, n is zero to six A-O is alkyleneoxy, as above, Also …
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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 March 9, 1990 and granted October 1, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 9, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 9, 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.