| 摘要 |
<p>A waterproof sealing material comprising a polyurethane foam, wherein the polyurethane foam contains an oxyethylene group, has a density of 0.3 to 0.9 g/cm<3>, a volumetric swelling ratio of 1.2 to 8, the percentage of loss in mass both when immersed in water at 70 DEG C for 7 days and when immersed in water at 23 DEG C for 180 days is not more than 3 %, and the waterproof sealing material comprises a molded or molded and processed product; and a method for preventing water leaking, using the above-mentioned waterproof sealing material on adjoining surfaces of segments in shield methods, in which a tunnel is constructed by joining segments together. In shield methods for constructing a tunnel or the like, the waterproof sealing material of the present invention is useful as a sealing material for segments with tenon and mortise joint means which is required to have a lower compression stress, since the sealing material has a small percentage of loss in mass, and shows a stable expansion performance over a long period. <IMAGE></p> |
