| 摘要 |
PURPOSE:To provide the foam which is produced by using only water as the blowing agent and has an excellent balance among properties such as elongation, tear strength and resiliency in spite of its low density. CONSTITUTION:A flexible polyurethane foam is obtained by reacting an active hydrogen component comprising an active hydrogen compound, a blowing agent and additives with an polyisocyanate component. The polyisocyanate component is an isocyanate mixture comprising diphenylmethane diisocyanate (MDI) and polyphenylmethane polyisocyanate (polymeric MDI) of an average functionality of 2.9 and having a mixing ratio of the diphenylmethane diisocyanate to the polyphenylmethane polyisocyanate of 1.0 or above, a 4,4'-MDI content of 45-60wt.% and a content of a 2,2'-/2,4'-MDI isomer mixture of 10-35wt.%. The blowing agent entirely consists of water. |
