Hydrophilic polyurethane
CA 2198859 C · Owner: Delaney, Pamela J. · Inventors: Delaney, Pamela J.; Leone, Shaun
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention is achieved by a polyurethane that is the reaction product of 4,4'-diphenylmethane diisocyanate (MDI) poly(oxyethylene) glycol (PEG), and , 1,4-butane diol (BDO). The equivalents of each reactant in the polyurethane is 4:1:3. Polyethylene glycol, 1450 (mw. 1305 - 1595) and particularly polyethylene glycol having a molecular weight of, about 1489 is preferred. The amount of hard segment (made up of chain extender and, MDI) is about 46 weight percent. The polymer is unusually tough and has good tensile, strength and wet strength.
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 1, 1994 and granted January 11, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended November 1, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 1, 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.