Improved process for preparing polyurethane foam
CA 2136261 C · Owner: Ck Witco Corporation · Inventors: Gerkin, Richard M.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for preparing a polyurethane foam according to the one-shot foaming process by reactions between a polyisocyanate and an active hydrogencontaining, component including water and an organic polyol wherein said reactions are conducted in the presence of a salt of a tertiary amine and a carboxylic acid, having hydroxyl functionality.
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
- Filed November 21, 1994 and granted August 10, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 21, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 21, 2016.
- 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.