Process for producing flexible polyurethane foam

A process for producing a flexible polyurethane foam, which comprises reacting an isocyanate compound and a polyol compound in the presence of a urethane-forming catalyst and a blowing agent, wherein as the isocyanate compound, an isocyanate compound containing from 50 to 100 mass % of tolylene diisocyanate in the isocyanate compound (100 mass %) is used, as the polyol compound, a polyol compound containing from 20 to 65 mass % of the following polyoxypropylene-polyoxyethylene polyol (A), and the following polyol (B) and (C) in the polyol compound (100 mass %) is used, and the flexible polyurethane foam to be produced contains substantially no atoms other than carbon atoms, hydrogen atoms, nitrogen atoms and oxygen atoms:

• (polyoxypropylene-polyoxyethylene polyol (A)):
• a polyoxypropylene-polyoxyethylene polyol (A) comprising (i) an oxypropylene block chain and (ii) an oxyethylene terminal block chain, which contains no oxyethylene group other than the oxyethylene terminal block chain, which is obtained by subjecting propylene oxide to ring opening addition polymerization to an initiator by using a double metal cyanide complex catalyst, and further subjecting ethylene oxide to ring opening addition polymerization by using an alkali metal compound catalyst or a phosphazenium catalyst, wherein the content of the oxyethylene group at the terminal is from 10 to 20 mass % in the polyoxypropylene-polyoxyethylene polyol (A) (100 mass %), and the hydroxyl value is from 15 to 56 mgKOH/g,
• polyol (B):
• a polyoxyalkylene polyol having a hydroxyl value of from 15 to 56 mgKOH/g and a total oxyethylene group content of less than 50 mass % and containing a polymer-dispersed polyol (B3) in a polyol compound,
• polyol (C):
• a polyoxyalkylene-oxyethylene polyol having a oxyethylene group content of from 50 to 100 mass % and a hydroxyl value of from 15 to 56 mgKOH/g.