METHOD FOR PRODUCING SOFT POLYURETHANE FOAM AND SHEET

摘要

Provided is a method with which it is possible to improve foam shrinkage and to produce soft polyurethane foam having excellent mechanical strength. Soft polyurethane foam is produced using a polyol (A) containing 40 to 100 mass% of a polyoxyalkylene polyol (A1). A method for producing the polyoxyalkylene polyol (A1) comprises: an initial step in which alkylene oxide is reacted by being fed, in an amount which is between 5 and 20 mass% in terms of initiator content, to a reaction solution including initiator and composite metal cyanide complex catalyst; and a polymerization step in which alkylene oxide is newly subjected to polymerization by being fed after the initial step. The temperature of the reaction system when feeding of the alkylene oxide is started in the initial step is between 120ºC and 165ºC, and the maximum temperature of the reaction system after the alkylene oxide has been fed in the initial step is between 15ºC and 50ºC higher than the temperature when feeding of the alkylene oxide is started.