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. 10, 2026
Filed:
Mar. 08, 2021
Toyobo Co., Ltd., Osaka, JP;
TOYOBO CO., LTD., Osaka, JP;
Abstract
A method for producing polyester resin containing an ethylene terephthalate structural unit of not less than 85 mol %, the method comprising: a melt-polymerization step of continuously performing melt-polymerization in two or more polymerization vessels by using an aluminium compound and a phosphorus compound as a polymerization catalyst; and a solid phase polymerization step of performing solid phase polymerization after the melt-polymerization step, wherein a polymerization in a final polymerization vessel of the melt-polymerization step satisfies a condition represented by the following formula: 410≤T*RT*(P/Al)≤580, wherein T represents a temperature (° C.) in the final polymerization vessel, RT represents residence time (hour) in the final polymerization vessel, and P/Al represents a molar ratio of phosphorus element to aluminium element in the polyester resin.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile