| 摘要 |
PURPOSE: To produce an open-cell rigid polyurethane foam excellent in moldability, workability, mechanical properties and dimensional stability. CONSTITUTION: A polyol mixture comprising 10-60wt.% hydroxyl-terminated reaction product (c) obtained by reacting an organic polyisocyanate (a) having an average functionality of 1.6-2.9 with a polyether polyol (b) having an average functionality of 2.0-6.0, an average molecular weight of 700-6000 and acontent of oxyethylene units of 10wt.% or below in such a ratio as to provide 1.3-10.0 equivalents of the hydroxyl groups of (b) per equivalent of the isocyanato groups of (a) and 20-90wt.% polyol (d) having an average molecular weight of 150-1200 and a content of oxyethylene units of 10wt.% or below is reacted with an organic polyisocyanate having an average functionality of 2.0-2.8 in the presence of a catalyst, a blowing agent and a foam stabilizer. |
