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:
Apr. 20, 1999
Filed:
Nov. 19, 1997
Joseph Galko, Akron, OH (US);
Douglas David Callander, Akron, OH (US);
Eugene John Burkett, Scott Depot, WV (US);
Edwin Andrew Sisson, Akron, OH (US);
Shell Oil Company, Houston, TX (US);
Abstract
A process for making a random polyalkylene terephthalate/naphthalate copolymer by synthesizing a bis-(hydroxyalkyl)-naphthalate composition under transesterification conditions, and subsequently combining the bis-(hydroxyalkyl)-naphthalate, a terephthalic acid, and an alkylene glycol under direct esterification conditions to form a random polyaklylene terephthalate/naphthalate copolymer. The preferred bis-(hydroxyalkyl)-naphthalate is bis-(2-hydroxyalkyl)-2,6-naphthalate, with bis-(2-hydroxyethyl)-2,6-naphthalate being the most preferred. Preferably, the bis-(hydroxyalkyl)-naphthalate is added at the initial stage of an acid-based polymer process, and polymerization is initiated or continued to produce a polyester copolymer. Alternatively, the bis-(hydroxyalkyl)-naphthalate is added to phthalate-based oligomers after the initial direct esterification stage, and polymerization is continued to produce a polyester copolymer.