Linear segmented polyurethaneurea and process for production thereof
CA 2089069 A1 · Owner: Goto, Seiji · Inventors: Hanahata, Hiroyuki; Goto, Seiji
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A linear segmented polyurethaneurea having a degree of branching (Nb) of 3 or less and obtained by chainextending a prepolymer with an organic diamine in an organic solvent comprising dimethylformamide or dimethylacetamide, wherein the prepolymer has an isocyanate group at the both ends thereof and comprises a stoichiometrically excessive amount of a diisocyanate component selected from 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate and 1,4-phenylene diisocyanate and a diol component having a number average molecular weight of 500 to 6000.
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 11, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended June 11, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 11, 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.