Multiple-layered patches for teeth whitening
CA 2451431 C · Owner: Yun, Sei-Young · Inventors: Chang, Sug-Youn; Yun, Sei-Young; Kim, Jong-Ho
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to a dry type patch for teeth whitening with multiple-layered structure of three or more layers. More particularly in the , dry type patch, a contact adhesive layer contains no peroxide and comprises a hydrophilic glass polymer as a base polymer so that it may have substantial adhesive strength when hydrated by water an active material reservoir layer , comprises peroxide as a teeth whitening agent and a backing layer is , impermeable to water. The dry type patch of the present invention has a superior teeth whitening effect and an excellent stability of peroxide in the patch at a high temperature since the peroxide-containing layer is covered with and …
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 June 21, 2002 and granted March 13, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 21, 2022.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 21, 2024.
- 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.