Organopolysiloxane and method for its preparation
CA 2022980 C · Owner: Dow Corning Toray Silicone Company, Ltd. · Inventors: Okawa, Tadashi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention provides an, organohydrogenpolysiloxane which does not have an average chemical structure as encountered with organopolysiloxanes prepared by equilibration polymerization reactions, but rather which has a clear defined chemical structure in which the position and number of silicon-bonded hydrogen groups is clearly defined. The organopolysiloxane has a branched structure in the vicinity of one terminal of the molecular chain and has the silicon-bonded hydrogen group at each of the resulting derivative terminals. The organopolysiloxanes can be addition-reacted with, for example organic, compounds having various functional groups to give organopolysiloxanes : having two …
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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 9, 1990 and granted March 16, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 9, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 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.