Preparation of polyurethane foams
CA 2122973 C · Owner: Horn, Peter · Inventors: Hinz, Werner; Jung, Ludwig; Horn, Peter
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 polyurethane foams preferably semirigid polyurethane foams having an improved, foam structure involves reacting: a) organic and/or modified organic polyisocyanates with b) polyhydroxyl compounds containing at least 2 reactive hydrogen atoms and, c) crosslinking agents which comprise at least one polyoxyalkylene-polyol having a mean functionality of from 3 to 8 and a hydroxyl number of from 200 to 1300 ppm and a content of alkali metal ions of from 150 to 1200 ppm in the presence of:, d) blowing agents e) if desired catalysts, f) inorganic and/or organic acids as additives and g) if desired auxiliaries.
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 May 5, 1994 and granted May 5, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 5, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 5, 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.