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. 06, 1993
Filed:
Nov. 19, 1992
Thomas R Maier, Brecksville, OH (US);
Surendra K Chawla, Copley, OH (US);
The Goodyear Tire & Rubber Company, Akron, OH (US);
Abstract
High molecular weight polyethyleneterephthalate resin is currently being used in vast quantities in manufacturing tire cord and in manufacturing trays for frozen foods which can be heated in either microwave or convection ovens. In some applications polyester resins having ultra-high molecular weights are required. For example, some techniques for producing polyester yarn by solution spinning demand ultra-high molecular weight polyester. Unfortunately, it becomes progressively more difficult and expensive to produce polyester resins having higher and higher molecular weights utilizing standard commercial polymerization techniques. This invention discloses a technique for preparing porous polyester beads which can be solid state polymerized very rapidly to ultra-high molecular weights. This invention more specifically discloses a process for preparing ultra-high molecular weight polyester resin which comprises: (1) dissolving a polyester prepolymer in a suitable organic solvent to produce a polyester prepolymer solution; (2) allowing droplets of the polyester prepolymer solution to drip into a coagulation bath to produce porous polyester beads; (3) recovering the porous polyester beads from the coagulation bath; (4) removing residual organic solvent from the porous beads; and (5) solid state polymerizing the porous polyester beads at an elevated temperature to produce the ultra-high molecular weight polyester resin.