| 摘要 |
PURPOSE:To produce a foamed polyurethane molding being lightweight and uniform, having good heat resistance and reduced in dusting during cutting by using a specified polyol. CONSTITUTION:A polyol component (A) comprising an aromatic-ring-containing polyol (a) of a hydroxyl value of 200-400 represented by the formula and an aliphatic polyol (b) of a hydroxyl value of 250-500, an aromatic polyisocyanate component (B) and 1-8 pts.wt., per 100 pts.wt. component A, dehydrating agent (C) are subjected to a foaming reaction in the substantial absence of a blowing agent according to the mechanical froth process. In the formula, X is any one group selected from among H, CH3, Cl and Br; Y is any one group selected from among CH2, C(CH3)2, SO2, O and a single bond; A is a propylene group or an ethylene group; and m+n=0-13. The ratio between components (a) and (b) in component A is usually about 10:90 to 40:60. When 2-20 pts.wt. per 100 pts.wt. component A is added, the effect of weight reduction can be further enhanced. |
