Ph-sensitive modified cellulose ester
CA 2251380 A1 · Owner: Lambert, Juanelle Little · Inventors: Cook, Phillip Michael; Lambert, Juanelle Little
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Cellulose esters according to formula (I): (C6H7O2)(OR)x(OR')y(OH)3-x-yn are described, where R is hydrophobic, R' is hydrophilic and not phthalyl or trimellityl, which may be designed, by the proper selection of R R', x, y, and n, to dissolve under mild to alkaline conditions and not before. A , coating comprising a modified ester according to formula (I) may be used for controlled-release applications, particularly for a cleaning formulation.
Read the whole patent
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 4, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended April 4, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 4, 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.