Patent ID: 7625954

Claim:
A process for producing molded flexible polyurethane foams, comprising reacting a) polyisocyanates with b) compounds having at least two hydrogen atoms which are reactive toward isocyanate groups, wherein the component b) comprises at least one polyether alcohol bi) which is prepared by means of a DMC catalyst only, a hydroxyl number in the range from 15 to 35 mg KOH/g, an ethylene oxide content in the range from 5 to 18% by weight, based on the total weight of the polyether alcohol, and an end block of ethylene oxide and propylene oxide having an ethylene oxide content of from 61.5 to 75% by weight, based on the amount of alkylene oxide in the end block, wherein the mass ratio of propylene oxide to ethylene oxide in the end block is reduced over the course of a metered addition in the preparation of the polyether alcohol bi) from 1:0.05-1:2 at the beginning of the metered addition to 1:5-1:20 at the end of the metered addition, and wherein the end block in the polyether alcohol bi) is from 5 to 50% by weight of the total weight of the polyether alcohol.