Method for production of cross-linked plastic foam
CA 2069761 C · Owner: Norsk Hydro A.S. · Inventors: Boreng, Raymond; Pedersen, Steinar; Dahl, Roger
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Method for production of a crosslinked foamed vinyl chloride containing polymer. A copolymer is produced where vinyl chloride and a glycidyl (epoxy) containing monomer and eventually another monomer are used in the polymerisation. A blowing agent is added to the polymer where the decomposition products of the blowing agent or the the decomposition products of the reaction products from the blowing agent are chemically reactive with the epoxy groups or their reaction products. Crosslinking is formed when the blowing agent or the reaction product of the blowing agent is decomposed. There is preferably used a monomer composition with 30-99.95 % vinyl chloride. The glycidyl containing monomer …
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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
- Filed November 29, 1990 and granted August 4, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 29, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 29, 2012.
- 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.