Process for producing a cationic polyurethane
Patent 3971764 Issued on July 27, 1976. Estimated Expiration Date: 
July 27, 1993. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
July 27, 1993. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3436361 3479310 3480592 3491050 3499852 3637540 3726838 3792023 InventorsAssigneeApplicationNo. 536365 filed on 12/26/1974US Classes:528/65, With reactant having two -XH groups428/425.1, Next to cellulosic525/453, Solid polymer derived from -N=C=X reactant and polyhydroxy reactant528/71Reactant contains at least one salt group, e.g., quaternary ammonium salt, etc.ExaminersPrimary: Welsh, M. J.Attorney, Agent or FirmAbstractCationic polyurethanes and a process for their production wherein a polyisocyanate, preferably a diisocyanate such as 2,4- or 2,6-tolylene-diisocyanate is reacted with an aliphatic dihydroxy compound substituted with an aliphatic side-chain of at least 10 carbon atoms to form a preliminary adduct or so-called prepolymer with terminal -- NCO groups. This prepolymer is then reacted for chain-lengthening with an aliphatic monomeric diol (A) containing a tertiary nitrogen atom convertible into an ammonium compound or an aliphatic monomeric diol (B) containing a tertiary nitrogen atom already converted into an ammonium compound. The new cationic polyurethanes are especially useful as sizing agents for the sizing of paper. | |
