The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 28, 1997
Filed:
Feb. 20, 1996
Valerie Sue Adams, Gray, TN (US);
James Earl Hataway, Kingsport, TN (US);
Kenneth Alan Roberts, Gray, TN (US);
Eastman Chemical Company, Kingsport, TN (US);
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.