Production method of prefoamed particles of polyolefin resin
CA 1285727 C · Owner: Japan Styrene Paper Corporation · Inventors: Kuwabara, Hideki; Izawa, Susumu; Yamaguchi, Toru
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Prefoamed particles of a polyolefin resin are produced by dispersing starting particles of the polyolefin resin, which contains a volatile foaming agent, in a dispersant in a pressure vessel heating, the resultant dispersion to a temperature of at least the softening point of the starting particles in said pressure vessel and then opening the vessel at one end thereof so as to release the starting particles and dispersant into an atmosphere of a pressure lower than the internal pressure of the vessel. The release of the starting particles and dispersant is performed while feeding a heating liquid.
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
- Granted July 9, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 9, 2008.
- 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.