Title:
METHOD OF PURIFYING LACTIDE
Document Type and Number:
WIPO Patent Application WO/2004/014890
Kind Code:
A1
Abstract:
It is intended to provide a method of purifying lactide whereby crude lactide can be purified while consuming less energy and causing no heat denaturation to thereby give D- or L-lactide having a high optical purity. In a method of purifying lactide, solid crude lactide, which contains 80% by mass or more of D- or L-lactide based on the total amount of D-lactide and L-lactide, is fed as a starting material into a feeding port 3 provided in the lower part of a cylindrical vertical purification column 1. Then the material is lifted while stirring with a stirrer 2 provided in the purification column 1. In the purification column 1, the material is purified due to countercurrent contact of the downward flow of melted D- or L-lactide with the upward flow of the material. Then the purified solid lactide is taken out as a product from a discharge port 4 provided in the upper part of the purification column 1.
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Inventors:
OHARA HITOMI (JP)
ITO MASAHIRO (JP)
SAWA SEIJI (JP)
FUJII TOMOAKI (JP)
OTAWARA KENTARO (JP)
ITO MASAHIRO (JP)
SAWA SEIJI (JP)
FUJII TOMOAKI (JP)
OTAWARA KENTARO (JP)
Application Number:
PCT/JP2003/010127
Publication Date:
February 19, 2004
Filing Date:
August 08, 2003
Export Citation:
Assignee:
KUREHA TEKUNOENJI K K (JP)
OHARA HITOMI (JP)
ITO MASAHIRO (JP)
SAWA SEIJI (JP)
FUJII TOMOAKI (JP)
OTAWARA KENTARO (JP)
OHARA HITOMI (JP)
ITO MASAHIRO (JP)
SAWA SEIJI (JP)
FUJII TOMOAKI (JP)
OTAWARA KENTARO (JP)
International Classes:
C07D319/12; C08G63/08; (IPC1-7): C07D319/12; B01D9/02
Domestic Patent References:
| WO2001072736A1 | 2001-10-04 | |||
| WO2001014290A1 | 2001-03-01 |
Foreign References:
| US6310218B1 | 2001-10-30 | |||
| JPH11292871A | 1999-10-26 |
Attorney, Agent or Firm:
Fujioka, Toru (17-12 Ebisu Nishi 1-chom, Shibuya-ku Tokyo, JP)
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