| 摘要 |
PROBLEM TO BE SOLVED: To obtain a hydrophilic urethane-based water barrier agent having good workability in handling of chemicals and excellent in water barrier effect improved in durability of a solidified substance. SOLUTION: This hydrophilic urethane-based water barrier agent mainly comprises a urethane prepolymer including terminal NCO groups obtained by reacting a hydrophilic aromatic polyol, which is obtained by carrying out an addition polymerization of ethylene oxide alone or ethylene oxide and propylene oxide to an aromatic polyhydric alcohol, with a polycyclic polyisocyanate, and then formulating 10-70% of a diluent having a high boiling temperature, a flash point at high temperature, low in offensive odor and free from active hydrogen. |
