ENERGY-ABSORBING RIGID URETHANE FOAM

PROBLEM TO BE SOLVED: To obtain the subject urethane foam having low density, high mechanical strength and high energy-absorbing performance by molding process. SOLUTION: This energy-absorbing rigid urethane foam is obtained using a polyisocyanate, a polyol, water, and (an auxliary; wherein (1) 100 pts.wt. of the polyol comprises (a) 50-90 pts.wt. of a polyester polyol with a hydroxyl number of 150-500 mgKOH/g, (b) 5-30 pts.wt. of a polyoxyalkylene polyol with the average number of' functional groups of 2-8 and a hydroxyl number of' 24-100 mgKOH/g and (c) 5-20 pts.wt. of a polyoxyalkylene polyol with the average number of functional groups of 2-8 and a hydroxyl number of 150-560 mgK 0H/g, and (2) the amount of the polyisocyanate to be used stands at a stoichiometric excess of 150-300 wt.% over that of the polyol.