Process for the preparation of aqueous polyurethane dispersions and solutions
CA 1111976 A · Owner: Bayer Aktiengesellschaft · Inventors: Grammel, Jurgen; Pedain, Josef; Nachtkamp, Klaus
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to a process for the preparation of aqueous solutions or dispersions of polyurethanes, in which process prepolymers which have at least two free isocyanate groups and contain chemicallyfixed hydrophilic groups and/or external emulsifiers which are not chemically fixed are reacted with chain lengthening agents in the aqueous phase characterized, in that the isocyanate prepolymer which is hydrophilically modified and/or contains an external emulsifier is mixed with chain lengthening agents selected from the group consisting of azines and hydrazones in the absence of water and the mixture obtained is then mixed with water. The present invention also relates to the …
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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
- Granted November 3, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 3, 1998.
- 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.