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:
Sep. 12, 1995
Filed:
Dec. 15, 1994
Ben Duh, Tallmadge, OH (US);
Shell Oil Company, Houston, TX (US);
Abstract
This invention includes a process for preparing a solid state polymerized poly(ethylene naphthalate)or PEN polymer comprising: (1) preparing a molten PEN polymer with an intrinsic viscosity of from about 0.25 dl/g to about 0.55 dl/g, (2) dispersing an inert gas into the molten PEN polymer to form a foamed PEN polymer with a void fraction of from about 0.10 to about 0.50, (3) forming the foamed PEN polymer into granules, (4) devolatilizing the granular PEN polymer at a temperature of from about 80.degree. C. to about 140.degree. C., (5) crystallizing the devolatilized PEN polymer at a temperature of from about 150.degree. C. to about 260.degree. C., and (6) solid state polymerizing the crystallized PEN polymer at a temperature of from about 235.degree. C. to about 265.degree. C. to form a solid state polymerized PEN product.