| 摘要 |
<p>There is described a polyol formulation comprising 20 to 65 wt. % of polyol if 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 percentage of N) of at least 0.2 wt. %. The formulation is especially useful for preparing a semi-flexible polyurethane foam having an emollient temperature of 120 degrees C or more which may be used in insulating pipes. 11 claims</p> |
