| 摘要 |
PURPOSE:The titled composition capable of providing a cured article of good water-stopping property, comprising an urethane prepolymer having aliphatic group-bonded urethane linkages and terminated with aromatic nucleus-bonded NCO groups. CONSTITUTION:A polyether-polyol (e.g., ethylene glycol/ethylene oxide adduct of an OH equivalent of about 800-4,000) is reacted with an aliphatic polyisocyanate (e.g., isophorone diisocyanate) at an OH/NCO ratio of about 1.2-8/1. The produced OH-terminated urethane prepolymer is reacted with an aromatic isocyanate (e.g., tolylene diisocyanate) at an OH/NCO ratio of about 1/(1.4-3) to form an NCO-terminated urethane prepolymer, which is then used as a moisture- curable urethane composition.
|
