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:
Jan. 03, 1995
Filed:
Feb. 09, 1994
Scott E George, Kingsport, TN (US);
Douglas C Hoffman, Kingsport, TN (US);
Eastman Chemical Company, Kingsport, TN (US);
Abstract
The present invention relates to a process for preparing copolyesters which involves two steps. The first step is a diol interchange step, and the second step is a polycondensation step. More specifically, the process involves (I) reacting in the presence of a polycondensation catalyst a dihydroxy terephthalate-containing compound having the formula: ##STR1## wherein n is 1 to 10 and at least 99% of the endgroups are ethylene glycol moieties; and 0.01 to 10 moles, based on moles of the dihydroxy terephthalate-containing compound, of a diol, and (II) polycondensing the reaction product of Step (I) to form a copolyester while excess diol is removed until desired molecular weight is obtained. This process does not include a transesterification of a dialkyl ester reaction or an esterification reaction which are usually used to produce copolyesters. Moreover, this process allows for polyethylene terephthalate and copolyesters prepared therefrom to be produced on an integrated production line.