Method for the production of polyactide from a solution of lactic acid or one of the derivatives thereof
US7488783B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 4, 2003 |
| Grant date | Feb 10, 2009 |
| Priority date | — |
| Expiry date | Nov 13, 2023 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G63/08
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process for the production of polylactide, the stages of which for the production and purification of lactide, starting from an aqueous solution of lactic acid or of its derivatives, includes evaporation of water with formation of oligomers, depolymerization to give lactide, condensation and then crystallization of the crude lactide product to give purified lactide, aqueous treatment of the residual fractions from the crystallization and polymerization of purified and/or prepurified lactide to give polylactide in an extruder and in the presence of catalysts. An alternative process includes carrying out the aqueous treatment before the crystallization.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.