502-97-6Relevant articles and documents
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Andreas et al.
, p. 141,143 (1962)
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METHOD FOR PRODUCING CYCLIC ESTER
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Paragraph 0113-0115, (2020/12/25)
In a method for producing a cyclic ester according to an embodiment of the present invention, a mixture (I) containing an aliphatic polyester, a specific polyalkylene glycol diether, and a sulfonic acid compound as a thermal stabilizer is prepared and heated in predetermined conditions to obtain a mixture (II) in a state of solution. Furthermore, heating of the mixture (II) is continued to distill, together with the polyalkylene glycol diether, a cyclic ester formed by the depolymerization reaction, and thus a distillate (III) is obtained. The cyclic ester is recovered from the distillate (III). At this time, a specific solubilizing agent is added to at least one of the mixture (I) or (II). In this production method, the sulfonic acid compound as the thermal stabilizer is contained in the mixtures (I) and (II) and the distillate (III).
METHOD FOR PRODUCING GLYCOLIDE
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Paragraph 0083-0093, (2019/10/30)
PROBLEM TO BE SOLVED: To provide a method for producing glycolides, with which glycolides can be produced more rapidly. SOLUTION: The method for producing glycolides comprises: an oligomer preparation step for obtaining a glycolic acid oligomer by heating an aqueous glycolic acid solution and by the dehydropolycondensation of the glycolic acid contained in the aqueous glycolic acid solution; and a depolymerization step for obtaining a glycolide by depolymerization of the glycolic acid oligomer in the presence of divalent iron ions. SELECTED DRAWING: None COPYRIGHT: (C)2019,JPOandINPIT