| 摘要 |
A carbamylbiuret-modified polyisocyanate of the formula: <IMAGE> wherein n is an integer of from about 1 to about 20; R is a divalent radical containing from about 1 to about 18 carbon atoms; and Y is a divalent radical selected from the group consisting of: <IMAGE> (a) <IMAGE> (b) <IMAGE> (c) <IMAGE> (d) <IMAGE> (e) <IMAGE> (f) <IMAGE> (g) wherein D is selected from the group consisting of O, S, and NH; X, X', and X'' are independently selected from the group consisting of oxygen and sulfur; R2 and R3 are independently selected from the group consisting of aryl of from about 6 to about 18 carbon atoms, alkyl containing from about 1 to about 6 carbon atoms, and cycloalkyl containing from about 3 to about 7 carbon atoms, provided that each of R2 and R3 differs from R; and R4, R5, R6, and R7 are independently selected from the group consisting of hydrogen, alkyl containing from about 1 to about 6 carbon atoms, cycloalkyl containing from about 3 to about 7 carbon atoms, phenyl, and benzyl. The compounds of the invention are useful for preparing urethane-based microcellular foams and elastomers.
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