Polyurethane-polyurea dispersions comprising hydrazine or hydrazide chain extenders

• Main Authors: Nietfeld, Jon P, Hansen, Richard G, Lu, Yongshang, Endle, Susan M, Iyer, Suresh
• Format: Patent
• Language: English
• Published: 16.07.2019
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP

A method of making a silyl-terminated polyurethane in an aqueous dispersion aqueous silyl-terminated polyurethane dispersions are described. In one embodiment, the polyurethane comprises a) urethane moieties derived from the reaction of a (i) a diol; (ii) a neutralized anionic water solubilizing compound; and iii) a diisocyanate. The polyurethane also comprises b) silyl terminal groups derived from an alkoxy silane compound having the formula (R3O)3SiR4-Z, wherein R3 is independently hydrogen or a C1-C4 alkyl; R4 is a divalent group selected from alkylene, alkylarylene, oxyalkylene; and Z is selected from the group consisting of -OH, -SH, -NR, -NH2, wherein R is an aromatic or aliphatic cyclic group. The polyurethane also comprises c) urea moieties derived from the reaction of an isocyanate terminated prepolymer and a difunctional hydrazine or hydrazide compound.