Co-initiated polyether polyol and process for its preparation

共引发的聚醚多元醇的制备方法，该方法包括以下步骤：(a)制备至少一种芳族引发剂，至少一种聚乙二醇和任选地一种或多种脂族引发剂的混合物，(b)在合适的烷氧基化催化剂存在下，步骤(a)中得到的混合物与至少一种每分子有3个或更多个碳原子的烯化氧反应，其中烯化氧的用量应使所得到的聚醚多元醇的OH值为150-400mg KOH/g和(c)回收共引发的聚醚多元醇。共引发的聚醚多元醇非常适于制备硬质聚异氰脲酸酯改性聚氨酯泡沫。这种泡沫具有良好的阻燃性。 Process for the preparation of a co-initiated polyether polyol, which process comprises the steps of (a) preparing a mixture of at least one aromatic initiator, at least one polyethylene glycol and optionally one or more aliphatic initiators, (b) reacting the mixture obtained in step (a) in the presence of a suitable alkoxylation catalyst with at least one alkylene oxide having three or more carbon atoms per molecule using such quantity of alkylene oxide that the polyether polyol obtained has a hydroxyl value in the range of from 150 to 400 mg KOH/g, and (c) recovering the co-initiated polyether polyol. The co-initiated polyether polyol is very suitable for (the preparation of rigid polyisocyanurate-modified polyurethane foams. Such foams have a good flame retardancy.