Method for preparing lactide using an ionic solvent

Patent metadata

Field	Value
Publication number	US-9102647-B2
Application number	US-201314061088-A
Country	US
Kind code	B2
Filing date	Oct 23, 2013
Priority date	Dec 31, 2012
Publication date	Aug 11, 2015
Grant date	Aug 11, 2015

Abstract

Disclosed is a method for preparing lactide by using a solvent. According to the method, since an ionic liquid is used as a solvent in a second step in the course of preparing lactide, it is possible to secure mobility of the resulting reactant, and decrease a reaction temperature. In addition, the ionic liquid absorbs moisture generated during the reaction, and thus prevents degradation of lactide which is susceptible to moisture. Furthermore, to the present method allows for the preparation of lactide successively through the continuous supply of lactic acid oligomers. Because the use of an ionic liquid minimizes the contamination of a reactive group with by-products, the use of a solvent for reactor washing is unnecessary. Further, owing to a high boiling point of the ionic liquid, the ionic liquid can be easily harvested and recycled.

First claim

What is claimed is:

1. A method for preparing lactide, comprising:
(a) synthesizing one or more lactic acid oligomers by polymerization of at least one lactic acid monomer;
(b) adding an ionic solvent to the synthesized one or more lactic acid oligomers; and
(c) synthesizing lactide from the one or more lactic acid oligomers added to the ionic solvent,
wherein the synthesis of lactides in the step (c) is carried out at a temperature of about 100 to 1000° C. under a pressure…

Assignees

• Hyundai Motor Co Ltd

Inventors

• Kim Si Hwan
• Hong Chae Hwan
• Han Do Suck
• Seo Ji Yeon

Classifications

• C07D319/12 Primary

  Chemistry & Metallurgy · mapped topic

• C07B61/00

  Chemistry & Metallurgy · mapped topic

• B01J6/00

  Operations & Transport · mapped topic

• C07D319/10 Primary

  Chemistry & Metallurgy · mapped topic