| 摘要 |
PURPOSE:To prevent the shrinkage of a closed-cell rigid polyurethane foam in the production process. CONSTITUTION:A rigid polyurethane foam is produced by compounding an isocyanate compound, an active hydrogen compound having >=2 active hydrogen groups and polyethylene fine powder as a shrinkage-preventing agent and foaming the obtained composition. A foaming agent substituting fluorocarbons and meeting the fluorocarbon restriction can be used in the above process and a rigid polyurethane foam having high quality can be produced while preventing abnormal shrinkage of the foam. |
