Method of making organosiloxane resins
CA 2010790 C · Owner: Dow Corning Limited · Inventors: Butler, Derek W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Liquid organosiloxane MTQ resins of the general formula Mx T y Q zn wherein M denotes a monofunctional T a trifunctional, and Q a tetrafunctional siloxane unit n has an average value of, from 4 to 14 x+y is not less than z and not more than 2 z and x/y has a value of from 2 to 9,are prepared by a method comprising (I) adding together (A) a silane of the general formula SiZ4, (B) a silane of the general formula RSiY3 and (C) a silane of the formula R3SiX or (C') a disiloxane of the formula (R3Si)2O in an acidic aqueous medium,and (II) allowing Components (A), (B) and (C) or (C') to react together. X denotes a halogen or alkoxy group, Y denotes X or -OSiR'3 Z, denotes an alkoxy group and …
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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 February 23, 1990 and granted January 12, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 23, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 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.