Method of post-polymerization stabilization of high activity catalysts in continuous polyethylene terephthalate production
US5898058A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 20, 1996 |
| Grant date | Apr 27, 1999 |
| Priority date | — |
| Expiry date | May 20, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08K5/524
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A continuous process for producing polyethylene terephthalate polyester from terephthalic acid and ethylene glycol uses a stabilizer, preferably containing phosphorous, to produce a high quality polyethylene terephthalate polyester which is relatively free of the acetaldehyde and discoloration which are associated with the post-polymerization activity of a polymerization catalyst. The stabilizer is preferably added at or after the end of the polymerization reaction prior to polymer processing to deactivate the polymerization catalyst and can increase the throughput of the polyester without adversely affecting the thermal stability of the polyethylene terephthalate polyester. Alternatively, the late addition of the stabilizer can increase the thermal stability of the polyester without adversely affecting the throughput of the polyethylene terephthalate polyester.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.