| 摘要 |
The present invention relates to polyurethane rigid foams formulations. More particularly, the present invention relates to polyurethane rigid foams formulations, prepared from aromatic polyester polyols, which show improved compressive strength. The formulations include an isocyanate reacting mixture, at least one polymeric diphenylmethane diisocyanate, having a functionality of at least 2.7, and at least one blowing agent; such that the stoichiometric index of the polyisocyanate to the isocyanate reacting mixture is 1.0-1.8. |
