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. 26, 1996
Filed:
Nov. 17, 1994
Thomas M Bartos, Naperville, IL (US);
Bruce I Rosen, Morton Grove, IL (US);
Jeffrey I Rosenfeld, Schaumburg, IL (US);
Amoco Corporation, Chicago, IL (US);
Abstract
Processes are disclosed for recovery and purification of dibasic aromatic acids or esters thereof from waste polyester film, fiber, bottles, manufacturing residues, and other manufactured articles. The processes comprise: depolymerization of polyester resin in a liquid solvent under conditions of elevated temperature and pressure suitable for opening of ester bonds to form a solution of dibasic aromatic acid or ester, polyol, organic impurities, and other components of the resin; crystallization of the dibasic aromatic acid or ester from the solution by flash crystallization to form a vapor containing a major mount of the polyol and solvent, and a slurry of dibasic aromatic acid or ester crystals in mother liquor; separation of crude dibasic aromatic acid or ester from the mother liquor; crystallization of retained organic impurities from the mother liquor solution by flash crystallization to a pressure in a range downward from about one atmosphere to form a slurry of mother liquor solids; recovery of mother liquor solids from the slurry; and recycle of the recovered mother liquor solids to the depolymerization.