STABILIZED POLY(BETA-METHYL- -VALEROLACTONE)

摘要

: The present invention is directed to polyester polyols containing the following recurring unit derived from .beta.-methyl- .delta.-valerolactone ? OCH2CH2CH(CH3)CH2CO ? in which the stability thereof has been improved by reducing the acid value to 0.25 or lower. This can be effected by heat treatment under reduced pressure to remove low-boiling compounds and/or by addition of an organic carbodiimide.