FLEXIBLE POLYURETHANE FOAM AND ITS PRODUCTION

PROBLEM TO BE SOLVED: To obtain a soft flexible polyurethane foam suitable for seat backs of automobiles, etc., while using water alone as the blowing agent. SOLUTION: A flexible polyurethane foam is produced by reacting a polyisocyanate with a polyoxyalkylene polyol component at an isocyanate index of 70-90 while using water alone as the blowing agent. The polyol component used comprises a polyoxyalkylene triol (A) having a hydroxyl value of 60-80mgKOH/g and a content of terminal ethylene oxide units (based on all the alkylene oxide units added to an initiator; the same applies hereunder) of 5-30wt.%, a polyoxyalkylene polyol (B) having a hydorxyl value of 40-60mgKOH/g and a content of terminal ethylene oxide units of 5-30wt.%, and a polyoxypropylene polyol (C) having a hydroxyl value of 35-300mgOH/g in a wt. ratio of A to B of (100:0)-(50:50) and a wt. ratio of (A+B) to C of (95:5)-(70:30).