Process for preparing elastomeric polyurethane or polyurethane-urea polymers prepared using low unsaturation polyethers
CA 2019060 C · Owner: Porter, James R. · Inventors: Porter, James R.; Turner, Robert B.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process is disclosed for preparing a polyurethane or polyurea elastomer by reacting in a closed mold a reaction mixture comprising a polyisocyanate and a relatively high equivalent weight polyether. The process is characterized by employing as said polyether a polymer or copolymer of propylene oxide having at least two hydroxyl groups per molecule an, equivalent weight from 1000 to 5000 and a monofunctional species content of about 0.04 milliequivalents/gram of polymer or less.
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 June 15, 1990 and granted November 12, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 15, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 15, 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.