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:
Jul. 23, 1996
Filed:
Dec. 14, 1994
Eugene J Burkett, Scott Depot, WV (US);
Douglas D Callander, Akron, OH (US);
Joseph Galko, Akron, OH (US);
Edwin A Sisson, Akron, OH (US);
Shell Oil Company, Houston, TX (US);
Abstract
This invention is an improved process for producing polyester copolymers, which employs a combination of an acid-based process and an ester-based process. The ester-based process is used to manufacture a low molecular weight naphthalate-based polymer, and the acid-based process is used to manufacture phthalate-based oligomers. The low molecular weight naphthalate-based polymer is combined with the phthalate-based oligomers, or the raw materials used to form the phthalate-based oligomers, to form a random polyester copolymer. Specifically, the process of the invention may be employed to manufacture, in an ester-based process, a low molecular weight polyethylene naphthalate polymer, which is then combined with polyethylene terephthalate oligomers produced in an acid-based process, and the acid-based process is then used to continue the polymerization reaction. Ester interchange reactions and further polymerization result in the production of a random polyethylene terephthalate/naphthalate copolymer.