PURPOSE: To obtain the titled molding suitable for use in heat-resistant parts, particularly for use where sealing by heat compression is required, by reacting a mixture consisting essentially of a specified polyol, a specified crosslinking agent and a specified polyisocyanate compound with the aid of a catalyst and a blowing agent.

CONSTITUTION: The titled molding is obtained by reacting a mixture consisting essentially of a polyol selected from polyetherpolyols having a functionality ≥4, an OH value of 20W60mgKOH/g, and a prim. OH content ≥30%, a crosslinking agent selected from compounds having a functionality ≥3, an OH value of 300W900mgKOH/g, and a prim. OH content ≥50%, and a polyisocyanate compound selected from polymethylenepolyphenyl polyisocyanate (derivatives) with the aid of a catalyst and a blowing agent under conditions including a mixing ratio, A/B, of 100/5W40 and an NCO/OH index of 75W105. This molding can be suitably used in heat-resistant parts for cars, aircraft, electric appliances, etc., particularly in use where sealing by heat compression is required.