| 摘要 |
PROBLEM TO BE SOLVED: To obtain an airless spray foaming type polyurethane foam excellent in flame-retardance. SOLUTION: This rigid polyurethane foam is obtained by subjecting a polyisocyanurate component, a polyol component, a blowing agent, a catalyst, a foam stabilizer and other auxiliaries to spray foaming. The polyol component contains >=40 wt.% of a polyester polyol compound obtained by esterifying a hydroxy component with one or more polybasic acid components of o-, m-, p-phthalic acid and their derivatives. Further a blowing agent of a gas at a normal temperature under normal pressure in an amount of <=10 wt.% based on the total of a mixed solution and the polyisocyanate is used as the blowing agent. Otherwise a reaction type amine catalyst composed of a hydroxyl group- containing amine compound in an amount of <=10 wt.% based on the polyol component is used as the catalyst. Otherwise a polyisocyanate component in which the ratio of triisocyanate in the case of n=1 in a polyisocyanate compound of the formula is >=20 mol.% and the ratio of 4,4'-MDI is >=35 mol.% is used. |
