| 摘要 |
There is described a polyol formulation comprising 20 to 65 wt.% of polyol of a first type having a number average molecular weight of greater than 800, a hydroxyl value of less than 200 mg KOH/g and an ethylene oxide content of less than 75 wt.% and, forming a miscible mixture therewith, 35 to 80 wt.% of polyol of a second type having a number average molecular weight of less than 1000, a hydroxyl value of greater than 300 mg KOH/g and an amine content (expressed in terms of the percentage of N) of at least 0.2 wt.%. The formulation is especially useful for preparing a semi-flexible polyurethane foam having a softening temperature of 120 DEG C or more which may be used in insulating pipes. |
