Catalytic compositions for the proparation of poly(ethylene terephthalate) with attenuated yellow color
US5608032A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 1995 |
| Grant date | Mar 4, 1997 |
| Priority date | — |
| Expiry date | Mar 28, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G63/866
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A catalyst composition for use in a polycondensation reaction for making poly(ethylene terephthalate) from terephthalic acid comprising: (a) an antimony salt catalyst present in a range from about 10 to about 1,000 ppm; (b) a metal salt catalyst of at least one of cobalt, magnesium, zinc, manganese, calcium, and lead, present in a range from about 10 to about 500 ppm; and (c) a phosphorus salt co-catalyst selected from the group consisting of alkali metal phosphates, alkali metal phosphites, alkali metal hypophosphites and alkali metal polyphosphates, present in a range from about 10 to about 500 ppm; all amounts are based on the metallic or phosphorus element relative to the theoretical yield of the poly(ethylene terephthalate), by weight, to be made from the terephthalic acid. The catalyst composition was found to have increased the reaction rate in the production of poly(ethylene terephthalate), as well as improved the color of the produced product, by reducing the degree of yellowness in the final poly(ethylene terephthalate) product. Attenuation of the yellowish color indicates a reduction in the amount of undesired side reaction product.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.