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:
May. 07, 2002
Filed:
Aug. 07, 2000
Mary Therese Jernigan, Kingsport, TN (US);
Carol Juilliard Greene, Kingsport, TN (US);
Perry Michael Murdaugh, Lexington, SC (US);
Alan Wayne White, Kingsport, TN (US);
Cheuk Chung Yau, Kingsport, TN (US);
Eastman Chemical Company, Kingsport, TN (US);
Abstract
The process for producing polyesters, and in particular, polyethylene terephthalate (PET) which includes the use of antimony catalyst that is acidic phosphorus additive involves the addition of the catalyst prior to or together with the additive. Moreover, the amount of additive is selected so as to provide a resin that is at least substantially free of non-acidic inorganic compounds such as antimony phosphate which can be formed by the reaction of the catalyst with the additive. The process preferably includes an esterification step, a prepolymer step, and a polymerization step with the antimony catalyst being added prior to, during, or after, the esterification step while the phosphorus-containing additive is introduced prior to or during the prepolymer stage. Polyesters having low levels of elemental phosphorus are also disclosed.