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:
Mar. 12, 1996
Filed:
Oct. 22, 1993
Applicant:
Inventors:
William H Heise, Kingsport, TN (US);
Daniel P Folk, Kingsport, TN (US);
Cheuk C Yau, Kingsport, TN (US);
Chester W Sink, Kingsport, TN (US);
Assignee:
Eastman Chemical Company, Kingsport, TN (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
560 78 ;
Abstract
Provided is a method useful for separating and removing impurities such as cyclohexane dimethanol (CHDM) and other additives from their mixture with dimethylterehthalate (DMT), formed during a depolymerization process such as methanolysis of poly(ethyene terephthalate) (PET), poly(cyclohexyldimethylene terephthalate) (PCT), or copolyers of PET and PCT. The separation and removal of CHDM is accomplished via either melt or solution crystallization of the DMT following excess methanol removal (via distillation) of the methanolysis reactor products.