PURPOSE: To obtain the titled polyoxytetramethylene glycol (PTMG) suitable as a material for spandex, by removing the low- and/or high molecular weight fraction(s) of PTMG according to the amount of water to be added to.
CONSTITUTION: (A) A high molecular weight fraction-free PTMG can be obtained by dissolving the orginal PTMG in methanol or ethanol followed by adding to the resultant solution at least such an amount of water as to develop a cloudiness in said solution to effect sedimentation of the high molecular weight fraction contained followed by separation. (B) A low molecular weight fraction- free PTMG can be obtained by dissolving the original PTMG in methanol or ethanol followed by adding to the resultant solution such an amount of water as to be either ≤1.7 times the weight of the methanol used or ≤3.0 times the weight of the ethanol used to effect removal of the low molecular weight fraction contained. (C) In this case, if the high molecular weight fraction-free PTMG obtained above is used, both high- and low molecular weight fraction-free PTMG will be obtained.
TONOMURA SHIYOUICHIROU
SATOU TOMIO
