Mixture of isocyanate-terminated polyurethane prepolymers having good adhesion
CA 2097796 A1 · Owner: Minnesota Mining And Manufacturing Company · Inventors: Kangas, Lani S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A blend of isocyanate-terminated polyurethane prepolymers comprising: (a) a fist prepolymer which comprises the reaction product of an at least essentially semicrystalline hydroxy-functional material and a polyisocyanate; (b) a second prepolymer which comprises the reaction product of a poly(tetramethylene glycol) ether and a polyisocyanate; and (c) a third prepolymer which comprises the reaction product of an essentially amorphous hydroxy-functional material and a polyisocyanate. The blend may also include a fourth prepolymer which comprises the reaction product of a slightly branched hydroxy-functional material and a polyisocyanate.
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 January 9, 1992. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended January 9, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 9, 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.