Process for solid-state polycondensation
US10604620B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 18, 2012 |
| Grant date | Mar 31, 2020 |
| Priority date | — |
| Expiry date | Aug 10, 2034 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G63/80
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A method and an apparatus for solid-state polycondensation of polyesters, preferably polyethylene terephthalate and/or copolymers thereof. The method and apparatus are both characterized by a solid-state polycondensation being performed with polyester prepolymer particles in a reaction chamber in which an absolute pressure is in the range from 10 mbar to 200 mbar, and a process gas flow in the range of an R-value of 0.005 to 0.05. The polycondensation is carried out over a time of from 2 to 30 hours and at a temperature of from 180° C. to 5° below a crystalline melting point of the polyester prepolymer particles in order to achieve an intrinsic viscosity of from 0.70 to 0.95 dl/g. The R value is defined as a ratio of an hourly amount of process gas (in kg) flowing through the reaction space to an hourly amount of polymer (in kg) flowing through the reaction space:
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.