| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a hard polyurethane foam having high flame retardancy and high quality of the appearance by the use of pentanes causing very little destruction of the environment as a foaming agent. SOLUTION: The method is for manufacturing a hard polyurethane foam from a raw material comprising a polyol, a polyisocyanate and a foaming agent consisting of pentanes. The polyol contains 60 wt.% or more of an aromatic polyester polyol of a hydroxyl value of 150-350 mgKOH/g. The polyisocyanate has an index of 180-300. The solubility of the pentanes in 100 g of the polyester polyol is 10-25 g. The polyester polyol is obtained from (A) one or more selected from 12-30C fatty acids and fats and oils and fatty acid compounds containing the acid(s) as a constituent, (B) a polybasic acid and (C) a polyhydric alcohol, in a mixing weight ratio of (A) to the reaction mixture of (A)-(C) of 5-40 wt.%. COPYRIGHT: (C)2004,JPO |
