| 摘要 |
PROBLEM TO BE SOLVED: To provide a flexible foam whose thickness is below 13 mm, whose maximum density is as low as about 400 kg/m<SP>3</SP>at the highest, and whose foam structure is uniform. SOLUTION: This method for producing low density polyurethane foam includes a process for foaming a reactive polyurethane forming composition prepared by mixing/agitating an isocyanate-containing component, an active hydrogen-containing component reactive with the isocyanate-containing component, a foaming agent, a surfactant (bubble regulating agent), and a catalyst system retarding the curing of the foam, a process for casting the foamed composition on a first support, a process for arranging a second support on the opposite surface of the first support in the cast foamed composition, and a process in which the foamed composition is expanded and cured by using the second support to obtain a polyurethane foam layer 12 having a density of 50-400 kg/m<SP>3</SP>and a thickness of 0.3-13 mm. The foam is useful as a seal member 10. COPYRIGHT: (C)2007,JPO&INPIT |
