Production method of prefoamed synthetic resin particles
CA 2030754 C · Owner: Naito, Masato · Inventors: Turugai, Kazuo; Sasaki, Hidehiro; Kuwabara, Hideki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Prefoamed synthetic resin particles are produced by dispersing foamable resin particles in a dispersing medium within a closed vessel, said foamable resin particles containing a water-soluble inorganic substance and a blowing agent therein, and then releasing the foamable resin particles and the medium into an atmosphere of a pressure lower than that inside the vessel whereby the thus-released foamable resin particles are allowed to undergo foaming.
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 23, 1990 and granted June 3, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 23, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 23, 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.