Porous structural unit and a method of preparing the same
CA 2001757 C · Owner: Tanaka, Hideharu · Inventors: Takahashi, Yutaka; Noguchi, Yoshihiro; Imai, Toshihisa
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention concerns a method of preparing a porous structural unit comprising a plurality of layers having different specific gravities by pressing and heating a material including resin particles between opposing molds having a temperature difference to thereby cause the fusion or bonding of the resin particles and a, porous structural unit which improves acoustic absorption properties and heat insulation properties and in which the specific gravity is continuously changed.
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 30, 1989 and granted October 29, 1996. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 30, 2009.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 30, 2011.
- 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.