Production of fine-celled foams from styrene polymers
CA 1192000 A · Owner: Basf Aktiengesellschaft · Inventors: Weber, Reinhold; Hahn, Klaus; Guenther, Wolfgang
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Production Of Fine-Celled Foams From Sytrene Polymers Abstract of the Invention, Fine-celled foams are produced by a process in which a styrene polymer is melted, the melt is mixed with a volatile blowing agent and a nucleating agent under superatmospheric pressure, the mixture is let down to atmospheric pressure, and the foam is cooled. The nucleating agent employed comprises from 0.02 to 2% by weight of the calcium salt of a long-chain fatty acid, and from 0.01 to 1% by weight of a finely divided, inorganic substance which is insoluble in the styrene polymer, a mixture of calcium stearate and magnesium oxide being preferred.
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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 August 13, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended August 13, 2002.
- 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.