Styrene polymer foam and the preparation thereof
CA 1081900 A · Owner: The Dow Chemical Company · Inventors: Killingbeck, Graydon W.; Suh, Kyung W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Stable medium density large cell size styrene polymer foam is extruded in large sections employing as blowing agents: chlorofluoromethane, bromochlorodifluoromethane alone or in admixture with minor quantities of other halogen containing carbon compounds to provide machinable foams of good dimensional stability.
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 15, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 15, 1997.
- 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.