OPEN-CELL RIGID POLYURETHANE FOAM AND THERMAL INSULATOR PREPARED THEREFROM

摘要

PURPOSE:To secure an excellent flowability in producing an open-cell rigid polyurethane foam even when a halogenated hydrocarbon blowing agent which exhibits a strong resin-dissolving power and has at least a hydrogen atom and a fluorine atom is used, and to produce a foam which has excellent thermal insulating properties and is used as a thermal insulator or a core of the insulator of a refrigerator. CONSTITUTION:An open-cell rigid polyurethane foam is prepd. by using a polyol component contg. at least 70wt.% polyol mixture consisting of 30-70wt.% arom. diamine-initiated polyether polyol and 70-30wt.% trimethylolpropane-initiated polyether polyol. Thus, the local degradation in the strengths of the foam due to an extreme orientation of cells is avoided, and a foam having strengths enough for a core of a thermal insulator and excellent thermal insulating properties is produced.