Preparation of flame-resistant soft polyurethane foams of reduced smoke density, and melamine/expandable graphite/polyether-polyol dispersions for this purpose
CA 2054287 C · Owner: Haase, Volker · Inventors: Fimmel, Karl; Gabbert, Hans-Juergen; Haase, Volker
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for the preparation, of flame-resistant soft polyurethane foams which produce less smoke in the event of fire involves reacting a) an organic polyisocyanate and/or a modified organic polyisocyanate with, b) a high-molecular-weight compound containing at least two reactive hydrogen atoms and, if desired c) a chain extender and/or crosslinking agent in the presence of, d) a mixture of flameproofing agents which contains: di) melamine , dii) expandable graphite and if desired, diii) at least one further flameproofing agent preferably a modified or unmodified, ammonium polyphosphate e) a blowing agent, f) a catalyst, and if desired, g) assistants and/or additives and …
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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 October 25, 1991 and granted March 28, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 25, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 25, 2013.
- 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
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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.