Process for the preparation of polyurethane foams employing polyol dispersions containing polyisocyanate polyaddition solids
CA 2086291 A1 · Owner: Grace, Oscar M. · Inventors: Grace, Oscar M.; Wujcik, Steven E.; Christman, Donald L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure, Addition of minor quantities of mono- or dicarboxylic acids to polyurethane foam formulations which employ polyisocyanate polyaddition polymer polyol dispersions prevents shrinkage and tightness in polyurethane foams prepared therefrom. If acid addition is made directly after dispersion preparation reduction, of polyol viscosity and more rapid stabilization against viscosity change is observed. 19
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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 December 24, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 24, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 24, 2014.
- 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.