Process for manufacturing an olefin resin foam
CA 1111600 A · Owner: Asahi-Dow Limited · Inventors: Watanabe, Seizaburo; Yamagishi, Tsukasa
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Process for manufacturing a polyolefin resin foam by adding to and mixing with a base polyolefin resin a cell control agent and a volatile blowing agent and extrusion- -expanding the resultant mixture, wherein the cell control agent comprises amorphous silica of pH 3.5 ~ 4.5 in the form of a nonporous microspheres with an average particle size of 5 ~ 100mµ and is added in an amount of 0.1 ~ 5 percent by weight of the base polyolefin resin. Employing this process the average cell size of the resulting foam does not vary significantly even though the blowing agent content is varied.
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 October 27, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 27, 1998.
- 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.