METHOD FOR PRODUCING SOFT POLYURETHANE FOAM AND SHEET

摘要

To provide a production process capable of producing a flexible polyurethane foam excellent in the mechanical strength, by which shrinkage of the foam can be reduced. A flexible polyurethane foam is produced by using a polyol (A) containing from 40 to 100 mass% of a polyoxyalkylene polyol (A1). The polyoxyalkylene polyol (A1) is produced by means of an initial step of supplying, to a reaction liquid containing an initiator and a double metal cyanide complex catalyst, an alkylene oxide in an amount of from 5 to 20 mass% based on the content of the initiator to carry out reaction, and a polymerization step of newly supplying an alkylene oxide to carry out polymerization reaction after the initial step, wherein in the initial step, the temperature of the reaction system when supply of the alkylene oxide is started is from 120 to 165°C, and the maximum temperature of the reaction system after supply of the alkylene oxide in the initial step is higher by from 15 to 50°C than the temperature when supply of the alkylene oxide is started.