Depolymerization process for recycling polyesters
US6136869A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 6, 1998 |
| Grant date | Oct 24, 2000 |
| Priority date | — |
| Expiry date | Oct 6, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/62
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for recovering suitable polyester feedstock material from recycled polyester includes the steps of depolymerizing the polyester into its component ester monomers and half-esters; separating the monomers and half-esters from other secondary materials; and mixing the component ester monomers and half-esters with additional monomers to produce a low molecular weight polyester. In a preferred embodiment of the invention the recycled polyester is contacted with a component monomer or oligomer thereof to liquefy the polyester before the polyester is depolymerized. The invention further provides an apparatus for carrying out the process. The apparatus includes a first reactor for depolymerizing the recycled polyester, a separator for separating ester monomeric components and half-esters from secondary materials produced in the first reactor, and a second reactor for producing a low molecular weight polyester from the liquefied separator products.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.