Abstract: The present invention relates to a polyurethane foam obtained from a polyurethane raw material containing polyol, isocyanate, a foam stabilizer, a catalyst and a foam-forming gas by a mechanical froth method, wherein the polyol contains a castor oil-based polyol having a viscosity at 25° C. of 2,000 mPa·s or less, and a polyether-based polyol, the castor oil-based polyol is contained in an amount of from 20 to 80 parts by weight per 100 parts by weight of the polyol, the polyether-based polyol is contained in an amount of from 20 to 80 parts by weight per 100 parts by weight of the polyol, the polyurethane foam has an apparent density of from 100 to 700 kg/m3, and compressive residual strain at 100° C. of 20% or less, and the polyurethane foam can be preferably used as a sealing material in a neighboring region of a heat source.

Abstract: The present invention relates to a polyurethane foam obtained from a polyurethane raw material containing polyol, isocyanate, a foam stabilizer, a catalyst and a foam-forming gas by a mechanical froth method, wherein the polyol contains a castor oil-based polyol having a viscosity at 25° C. of 2,000 mPa·s or less, and a polyether-based polyol, the castor oil-based polyol is contained in an amount of from 20 to 80 parts by weight per 100 parts by weight of the polyol, the polyether-based polyol is contained in an amount of from 20 to 80 parts by weight per 100 parts by weight of the polyol, the polyurethane foam has an apparent density of from 100 to 700 kg/m3, and compressive residual strain at 100° C. of 20% or less, and the polyurethane foam can be preferably used as a sealing material in a neighboring region of a heat source.