Electret filters
CA 2056579 A1 · Owner: Matsuura, Satoshi · Inventors: Kishiba, Tsuneo; Shinagawa, Yoshio; Matsuura, Satoshi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
ABSRACT, An electret filter made of a resin whose angle of contact upon wetting with pure water is no smaller than 95 degrees, as well as an electret filter made of a resin whose angle of contact upon wetting with pure water has been adjusted to no smaller than 95 degrees by addition of silicone oil. Those electret filters have high trapping efficiency and their ability to trap particulates especially, cigarette smoke, will not deteriorate even if they are continuously used. Therefore, they can advantageously be used as filter media in many applications such as home and industrial air conditioners, air cleaners fan heaters, vacuum cleaners, and air conditioning systems for common equipment.
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 November 28, 1991. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 28, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 28, 2013.
- 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.