Isocyanate prepolymers produced from toluene diisocyanate residue dissolved in toluene diisocyanate
CA 2223475 A1 · Owner: Pisipati, Jyothi S. · Inventors: Slack, William E.; Pisipati, Jyothi S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A substantially solid free isocyanate prepolymer is made by reacting an isocyanate mixture which is made up of a toluene diisocyanate residue containing monomeric toluene diisocyanate and optionally, additional monomeric toluene diisocyanate in an amount such that the total NCO content is at least 37% with a polyether polyol having an ethylene oxide content of at least 30%. The polyether polyol has a molecular weight of from about 200 to about 6,000 and a functionality of from 2 to 6. The product prepolymers are particularly useful in the production of polyurethanes.
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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 4, 1997. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 4, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 4, 2019.
- 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.