PURPOSE: To produce a rigid polyurethane foam which has high strength and a high effective compression ratio and which, even when thin, has high impact- absorbing or impact-damping properties by using water as a foaming agent.
CONSTITUTION: An alcohol ingredient comprising 55-95wt.% (exclusive of 55) polyoxyalkylene polyol having an average functionality of 2.5-6 and a hydroxyl value of 400-600mgKOH/g and a monohydric alcohol having a hydroxyl value of 400-1,800mgKOH/g is reacted with an aromatic polyisocyanate using water as a foaming agent in an amount of 2.5-5.5 pts.wt. per 100 pts.wt. the alcohol ingredient to obtain a rigid polyurethane foam. The alcohol ingredient may further contain a plyoxyalkylene polyol having an average functionality of 2-3.5 and a hydroxyl value of 25-60mgKOH/g and/or a polyol which is an alkylene oxide adduct of an organic polyamine.
OKADA KAZUO
TSUCHIYA KOICHI
MITSUBISHI MOTORS CORP