Method for the preparation of branched organopolysiloxane
CA 2081129 C · Owner: Suzuki, Toshio · Inventors: Ogawa, Takuya; Suzuki, Toshio
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention is a method for the preparation of a branched organopolysiloxane in which a polysiloxane with the formula SiO2 constitutes the branching center or branch origin and the terminal on only one side of the diorganopolysiloxane is bonded to the branch origin wherein this bonding is exactly to the branch origin. Specifically the method for preparation of the branched polyorganosiloxane comprises the reaction of an alkali metal compound with a silanol-containing polysiloxane described by formula, {SiO4/2}x{R1 2(OH)SiO1/2}y{R1 3SiO1/2}z{RO1/2}u wherein each R1 is independently selected from a group consisting of C1-8 alkyls; haloalkyls, alkenyls and aryls;, R is selected from …
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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 October 22, 1992 and granted September 29, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 22, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 22, 2014.
- 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.