Process for the preparation of silarylenesiloxane-diorganosiloxane copolymers
CA 2351071 A1 · Owner: Wacker-Chemie Gmbh · Inventors: Egerter, Norbert; Muller, Philipp
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Linear-chain copolysiloxanes comprising units of the general formulae (1) and (2), -(R1R2SiO)a- (1) -(R3R4Si-R7-SiR5R6O)b-R3R4Si-R7-SiR5R6- (2) the end-groups of which may be Si-H or Si-OH are prepared by reacting:, (A) diorganopolysiloxanes of the general formula (3) HO-(R1R2SiO)a-H (3), with, (B) silarylenesiloxane compounds of the general formula (4) H-(R3R4Si-R7-SiR5R6O)b-R3R4Si-R7-SiR5R6-H (4) in the presence of (C) a transition metal catalyst wherein R1, and R2 are , optionally, substituted and optionally heteroatom-containing hydrocarbon radicals R3, R4, R5, and R6 are optionally halogen-substituted and optionally heteroatom-containing aliphatically or aromatically unsaturated C1-20 …
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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 June 19, 2001. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 19, 2021.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 19, 2023.
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Timeline
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.