| 摘要 |
PROBLEM TO BE SOLVED: To provide a carboxy group-containing polyester polyol with a decreased content of a dimethylolalkanoic acid in spite of the use of the dimethylolalkanoic acid. SOLUTION: The carboxy group-containing polyester polyol is obtained by ring-opening polymerization of a lactone using the dimethylolalkanoic acid, has a number-average molecular weight of 250-2,000, and contains therein the dimethylolalkanoic acid of at most 1 wt.% based on the total amount of the dimethylolalkanoic acid, the lactone and the carboxy group-containing polyester polyol. The carboxy group-containing polyester polyol is obtained by ring-opening polymerizing the lactone, subsequently causing the dimethylolalkanoic acid to deposit and separating and removing the deposited dimethylolalkanoic acid. COPYRIGHT: (C)2007,JPO&INPIT
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