| 摘要 |
PROBLEM TO BE SOLVED: To provide a process for producing a flame-retardant rigid polyurethane foam and a flame-retardant rigid polyurethane foam produced thereby by solving the problem that though the reduction in or the abolition of the use of F11, a conventional blowing agent used for rigid polyurethane foams, is requested because of the ozone depletion potential of F-11 and the substitution of F-11, which is not flammable, with F-14b is an urgent need, the use of F-141b leads to the degradation in flame retardance of rigid polyurethane foams since it is flammable. SOLUTION: Even when F-141b is used, a flame-retardant rigid polyurethane foam can be obtd. by using a polyester polyol in an amt. of 5wt.% or higher of the whole polyhydroxyl compds. The polyester polyol used is obtd. by the esterification of a hydroxyl compd. component contg. 5-100wt.% arom. hydroxyl compd. and a polybasic acid component comprising o-, m-, or p-phthalic acid, trimellitic acid, a deriv. such as dimethyl phthalate, or their mixture. |
