Method for the preparation of methyl ethers of polyether polyols employing dimethylsulfate as a methylating agent
CA 2029509 C · Owner: Basf Corporation · Inventors: Greenough, Ronald Edward; Houben, Jochen; Birnbach, Stefan
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for preparing an etherified, polyoxyalkylene derivative of the formula (See Fig. I), wherein R1 and R4 are identical or different and are each independently C1-C20 alkyl, C3-C5 alkenyl C6-C20 aryl, C6-C20 alkyl aryl, C6-C20 cycloalkyl and mixtures thereof, R2, and R3 are identical or different and independent of each other are H, CH3, CH3CH2, and mixtures thereof m, m' and n, are identical or different and are each greater than or equal to zero, with the proviso that m + m' + n is from 3 to 300; by reacting a polyoxyalkylene compound of the formula -18-
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 November 7, 1990 and granted January 6, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 7, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 7, 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.