Title:
PRODUCTION OF LACTIDE
Document Type and Number:
Japanese Patent JP2560259
Kind Code:
B2
Abstract:
PURPOSE: To simply and economically obtain a high-purity lactide by polycondensing lactic acid and then thermally decomposing the resultant polylactic acid under specific conditions.
CONSTITUTION: Purified lactic acid or crude lactic acid obtained in a fermenting step, etc., or containing inorganic salts is vacuum distilled and dehydrated, preferably at 60-100°C to provide a concentrated lactic acid, which is then usually polycondensed at 100-200°C (preferably 100-180°C) under ≤30mmHg (preferably ≤10mmHg) for 5-20hr to afford polylactic acid having 2000-20000 weight- average molecular weight. Ferrous oxide as a catalyst in an amount of ≤5wt.% is then added to the resultant polymer and catalytic thermal decomposition of the polymer is usually carried out at 200-300°C (preferably 230-300°C) under 1-30mmHg (preferably 1-15mmHg) for 1-3hr. Thereby, the objective lactide is obtained.
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Inventors:
MORITA MIKIO
YUMOTO ISAO
IKEDA KOJI
HIRAMA YASUKO
YUMOTO ISAO
IKEDA KOJI
HIRAMA YASUKO
Application Number:
JP25652894A
Publication Date:
December 04, 1996
Filing Date:
October 21, 1994
Export Citation:
Assignee:
KOGYO GIJUTSUIN
International Classes:
C07D319/12; B01J23/745; C07B61/00; C07B63/00; (IPC1-7): C07D319/12; B01J23/745; C07B63/00
Attorney, Agent or Firm:
Director, Hokkaido Institute of Industrial Technology (3 outside)