Patent ID: 8357730

Claim:
A process for producing a flexible polyurethane foam, which comprises reacting a polyol mixture with a polyisocyanate compound in the presence of an urethane-forming catalyst, a blowing agent and a foam stabilizer, characterized in that the polyol mixture comprises the following polyol (A), the following polyol (B) and the following monool (D), and the ratio of all active hydrogen-containing compounds in all materials other than the polyisocyanate compound to the polyisocyanate compound is at least 90 by isocyanate index, wherein: Polyol (A) is a polyoxypropylene polyol having an average of from 2 to 3 hydroxyl groups, a hydroxyl value of from 10 to 60 mgKOH/g and is obtained by ring-opening polymerization of only propylene oxide to an initiator using a phosphazene compound, a Lewis acid compound or an alkali metal compound catalyst; Polyol (B) is a polyoxypropylene polyol having an average of from 2 to 3 hydroxyl groups and a hydroxyl value of from 70 to 250 mgKOH/g and is obtained by ring-opening polymerization of only propylene oxide to an initiator; and Monool (D) is a polyoxypropylene monool having a hydroxyl value of from 10 to 200 mgKOH/g and is obtained by ring-opening polymerization of only propylene oxide to an initiator, and wherein from 50 to 100 mass % of the polyol (A) is a polyether diol having 2 hydroxyl groups, wherein the monool (D) is present in an amount of 2-5 mass %, and wherein the polyol (C) is present in the mixture in an amount up to 10 mass % of the following polyol (C), based on the entire polyol mixture: Polyol (C) is a polyether polyol having an average of from 2 to 6 hydroxyl groups, a hydroxyl value of from 10 to 60 mgKOH/g and an oxyethylene group content of from 50 to 100 mass %.