Process for preparing copolyesters of terephthalic acid ethylene glycol and 1 4-cyclohexanedimethanol exhibiting a neutral hue high clarity and increased brightness
US5681918A · kind A · utility
137Cited by
6References
1Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 20, 1996 |
| Grant date | Oct 28, 1997 |
| Priority date | — |
| Expiry date | Feb 20, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G63/85
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
This invention relates to a three step process for preparing copolyesters exhibiting a neutral hue, high clarity and increased brightness. The process involves reacting terephthalic acid, ethylene glycol, and 1,4-cyclohexanedimethanol in a feed mole ratio of total glycols to dicarboxylic acid of 1.7:1 to 6.0:1, at a temperature of 240.degree. C. to 280.degree. C., and a pressure of 15 psig to 80 psig to form an esterification product; adding a polycondensation catalyst and a toner; and polycondensing the product at a temperature of 260.degree. C. to 290.degree. C. and a reduced pressure to form a high molecular weight copolyester.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.