| 摘要 |
PROBLEM TO BE SOLVED: To provide a back-filling composition free from risk of ignition even if mass-filled, workable safely and nondeformable after worked. SOLUTION: This back-filling composition comprises an A-liquid which is prepared by incorporating an amine catalyst, water, a silicone foam stabilizer and antiscorching agent in a polyol as the mixture of (1) a polyether polyol with ethylene oxide accounting for 10-90 wt.% of the total alkylene oxide added in the molecule and (2) a 2nd polyether polyol with only propylene oxide added in the molecule in the weight ratio (1): (2) of (10:90) to (50:50) and a B-liquid containing a polymeric MDI in the weight ratio A-liquid: B-liquid of (1:1) to (1:3). This composition has the following characteristics: the exothermic internal temperature when freely expanded is <=200 deg.C and the foam density 0.030-0.120 g/cm<3> . |
