Method for the preparation of organopolysiloxane
CA 2060143 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
A method for the preparation of an, organopolysiloxane which contains in each molecule at least one phenyl group and at least one silicon-bonded hydrogen atom is disclosed, said method comprising reacting (I) an organopolysiloxane having a molecular weight not exceeding 100,000 and containing in each molecule at least one phenyl group and at least one alkoxy group with (II) 1,1,3,3-tetramethyldisiloxane wherein the reaction is carried out in the presence of an aqueous hydrochloric acid solution, this aqueous solution preferably further comprising an alcohol.
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 January 28, 1992 and granted August 18, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 28, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 28, 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.