| 摘要 |
Compsn. comprises a blowing agent, a polyester polyol (II), a phosphorus-contg. polyol (III), a polymeric polysiocyanate and an isocyanurate catalyst. (II) is prepd. by transesterification with a glycol of m.wt. 60-400 of a residue remaining after dimethyl terephthalate and methyl p-toluate have been removed from the oxidn. prod. of p-xylene in the prepn. of dimethyl terephthalate, or by esterification with an alkylene oxide of a carboxyl functional residue resulting from the removal of terephthalic acid prod. from the mixt. obtd. by oxidising p-xylene. - The alkylene oxide is ethylene oxide, propylene oxide or butylene oxide. (III) is a propylene oxide adduct of a di (1-4C alkyl) pyrophosphoric acid. The NCO/OH ratio of the compsn. is 3:1 to 6:1.
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