Ultrathin membrane of polymethacrylate or polycrotonate and device provided with ultrathin membrane
CA 2026702 C · Owner: Kaiya, Norihiro · Inventors: Kaiya, Norihiro; Otsu, Takayuki; Yamada, Akira
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An ultrathin polymeric membrane has a membrane thickness of 10 to 1,000 .ANG.. The membrane is constituted of polycrotonate and obtained by the spin coating method or by the Langmuir-Blodgett method. The polycrotonate contains recurrent units represented by the formula (I) (I), wherein R represents a hydrocarbon group selected from the group consisting of a branched alkyl group having 3 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms a substituted alkyl group having 2 to 6 carbon atoms a, substituted cycloalkyl group having 3 to 10 carbon atoms and a siloxanic hydrocarbon group.
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 October 2, 1990 and granted April 12, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 2, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 2, 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.