| 摘要 |
<p>PURPOSE: A rigid polyurethane foam obtained by reacting a polyol component and an isocyanate composition and process for producing the same are provided which show excellent insulation and mechanical characteristics even at low temperatures. CONSTITUTION: A foam is prepared by reacting a polyol component and an isocyanate composition in the presence of a foaming agent, a reaction catalyst, a foam stabilizer, and other additives, wherein the polyol component contains (a) 20 to 60% by weight of polyether polyol obtained from the addition of propylene oxide and ethylene oxide to sorbitol, (b) 10 to 40% by weight of polyether polyol obtained from the addition of propylene oxide and ethylene oxide to pentaerythrol, (c) 10 to 20% by weight of polyether polyol obtained from the addition of propylene oxide and ethylene oxide to sucrose, (d) 10 to 20% by weight of polyester polyol obtained from the addition of propylene oxide and ethylene oxide to phthalic anhydride, (e) 10 to 20% by weight of polyester polyol obtained from the addition of propylene oxide and ethylene oxide to bisphenol A and the isocyanate component is a polymer-type 4,4'-diphenylmethanediisocyanate having a functional number of 2.7 to 3.1.</p> |
