Kureha Corporation

Takenori Tose

Yoshinori Suzuki

Fuminori Kobayashi

Toshihiko Ono

Yuta Yamadoi

Haruyasu Yamaji

Nanako Saigusa

Motoharu Shoda

The object of the present invention is to provide a method for producing glycolide, with which a production rate of glycolide can be further enhanced. The method for producing glycolide that achieves the object described above includes: an oligomer preparation step of heating an aqueous glycolic acid solution and subjecting glycolic acid contained in the aqueous glycolic acid solution to dehydrating polycondensation, to obtain a glycolic acid oligomer; and a depolymerization step of depolymerizing the glycolic acid oligomer in the presence of ferrous ions to obtain glycolide.

Method for producing glycolide

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 cyclic ester

The object of the present invention is to provide a glycolide production method capable of further increasing the production rate of glycolide. The glycolide production method according to the present invention includes adding metal iron to an aqueous glycolic acid solution, subjecting glycolic acid contained in the aqueous glycolic acid solution to which the metal iron is added, to dehydrating polycondensation to obtain a glycolic acid oligomer, and heating and depolymerizing the glycolic acid oligomer to obtain glycolide.

Glycolide production method

Growing community of inventors

Tokyo, Japan

Takenori Tose