Improved process for preparing poly(ethylene terephthalate)
US4110316A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 1977 |
| Grant date | Aug 29, 1978 |
| Priority date | — |
| Expiry date | Apr 14, 1997 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G63/78
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A continuous process is disclosed for direct esterification of terephthalic acid with ethylene glycol, followed by low-pressure polymerization in a continuous polymerizer and in a finisher polymerizer to produce polyester suitable for melt-spinning into yarn for textile uses. Vapors from the polymerizers are condensed in spray condensers to recover glycol liquid, which is recycled to the direct esterification reaction. Efficient operation of the spray condensers at absolute pressures of less than 60 millimeters of mercury is achieved by addition of substantially dry ethylene glycol to lower the water content of condensate used in the sprays.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.