Silicone polyether copolymers and polyurethane foams prepared therefrom
CA 2002340 C · Owner: Union Carbide Chemicals And Plastics Company Inc. · Inventors: Murphy, Gerald Joseph; Blevins, Charles Henry; Matlock, Paul Lumpkin
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Novel compositions of silicone/polyether block copolymers are provided which are useful as surfactants in several classes of polyurethane foam production. While conventional copolymers have a polysiloxane backbone with pendant polyethers the, surfactants of the present invention are the reverse with siloxane pendants on a polyether chain. These novel non-hydrolyzable polysiloxane polyoxyalkylene copolymers which are characterized by an "inverted" structure, i.e. polyoxyalkylene backbones with lateral and/or terminally pendant polysiloxanes represent species that are of a narrow molecular weight and compositional distribution and are free of unreacted polyether or non-modified silicone oil …
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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 November 6, 1989 and granted April 23, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 6, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 6, 2011.
- 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.