Process for the preparation of organopolysiloxane resin
CA 2134766 C · Owner: Mueller, Reinhardt · Inventors: Mautner, Konrad; Mueller, Reinhardt; Weidner, Richard
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for producing organopolysiloxane resin is characterized by the following steps. In a first step a silane having the, formula (I): R3SiOR1 and/or its hydrolysate, and a silane having the formula (II): Si(OR2)4 and/or its partial hydrolysate, in which R R1 and R2 have the meaning given in the first claim as well as if required other organosilicic compounds are, reacted with water in the presence of acid and the resulting alcohol is at least partially distilled. In a second step the, homogeneous reaction mass from the first step is reacted in the presence of bases and water-insoluble organic solvents and the, water and alcohols are removed by distillation. In a third step the …
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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 May 13, 1993 and granted December 30, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 13, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 13, 2015.
- 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
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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.