Polythiol compound, and optical material and product produced therefrom
CA 2033239 C · Owner: Nguyen, Chau · Inventors: Nguyen, Chau; Ohkubo, Tsuyoshi; Okada, Reisuke
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention relates to a polythiol compound and an optical material therefrom. Having a rigid 1,4-dithian ring which increases the refractive index and Abbe's number the, polythiol compound used for the production of an optical material imparts the optical material with high heat resistance and excellent mechanical properties as well as excellent optical properties.
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 December 27, 1990 and granted October 1, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 27, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 27, 2012.
- 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.