Method for producing glycolide
US9512100B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 25, 2014 |
| Grant date | Dec 6, 2016 |
| Priority date | — |
| Expiry date | Mar 25, 2034 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G63/06
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A method for producing glycolide (GL) by heating a glycolic acid oligomer (GAO) to depolymerize the GAO. The method for producing GL comprises: a step 1 of heating a mixture containing a GAO having a terminal COOH concentration of 400 eq/t or less and a polar organic solvent to a GAO depolymerization temperature under ambient pressure or reduced pressure; a step 2 of continuing the heating at the temperature for depolymerizing of the GAO and then codistilling out the produced GL and the solvent from the depolymerization reaction system to the outside the reaction system; and a step 3 of obtaining GL from the codistillation product. In the method for producing GL, the GAO is preferably prepared by a GAO production method which comprises a step of condensing glycolic acid (GA) and a dehydration step of continuing the heating together with a polar organic solvent or a depolymerization reaction solution to allow the GA condensation reaction to continue.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.