| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polyurethane composition which can react with atmospheric moisture to give a cured product excellent in yellowing resistance, flexibility, and elongation by including an isocyanato-terminated urethane prepolymer obtained by reacting a polycyclic aliphatic diisocyanate with an active hydrogen compound. SOLUTION: A polycyclic aliphatic diisocyanate is reacted with an active hydrogen compound to obtain an isocyanato-terminated urethane prepolymer having an NCO content of 0.5-8.0 wt.%. The prepolymer is optionally combined with e.g. a reaction promoting catalyst to obtain a one-package moisture-curable polyurethane composition. It is desirable that the polycyclic aliphatic diisocyanate contains either 2,5-diisocyanatomethylbicyclo[2,2,1]heptane or 2,6- diisocyanatomethylbicyclo[2.2.1]heptane. The active hydrogen compound used is a polyhydric alcohol, a polyether polyol, a polytetramethylene ether glycol or the like.
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