Improved polyvinylsiloxane impression material
CA 2369903 C · Owner: Dentsply International Inc. · Inventors: Hare, Robert V.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Improved two component polymerizable polyorganosiloxane compositions are described, particularly for use in making dental impressions having improved , tear strength and wettability. Improved tear strength results from inclusion of a quadri-functional polysiloxane having a vinyl content of 0.16 to 0.24 mmole/g. Working time is maintained by including sufficient amounts of a retarder composition that delays onset of the vinyl polymerization. Wettability is improved by including a surfactant resulting in a surface contact angle with water at three minutes of less than 50~. The surfactant chosen has an HLB of 8-11, such that the wetting contact angle is achieved within less than two …
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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 March 8, 2000 and granted May 17, 2011. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 8, 2020.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 8, 2022.
- 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.