Method of making expandable styrene-type polymer beads
CA 1191000 A · Owner: American Hoechst Corporation · Inventors: Mostafa, Mohamad A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Expandable styrene-type polymer beads having a short cooling time are obtained by a method wherein styrene-type polymer beads are impregnated with a blowing agent preferably as a step separate and independent of the polymerization step or in the same suspension polymerization reactor after a substantial completion of the polymerization, in an aqueous suspension comprising styrenetype polymer beads, a blowing agent, a suspending agent at least, 0.0001% of a halide salt of a transition metal selected from the group consisting of iron, titanium, vanadium chromium, manganese, cobalt, nickel and copper or a mixture thereof, and, at least 0.001% of glycerol monodi-, or tri-ester of a fatty, acid …
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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 July 23, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 23, 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.