| abstract |
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 (R 3 O) 3 SiR 4 —Z, wherein R 3 is independently hydrogen or a C 1 -C 4 alkyl; R 4 is a divalent group selected from alkylene, alkylarylene, oxyalkylene; and Z is selected from the group consisting of —OH, —SH, —NR, —NH 2 , 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. |