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. 27, 2001
Filed:
Jul. 15, 1999
Sung-Il Kim, Seoul, KR;
Korea PTG Co., Ltd., Ulsan, KR;
Abstract
An improved process for Polytetramethylene-Ether-Glycol-Diesters of the formula R—CO—O(CH,—CH,—CH,—CH,—O)n-COR,, in which R and R,are identical or different and are alkyl radicals or derivatives thereof, by polymerization of tetrahydrofuran in the presence of a heterogeneous polymerization catalyst and in the presence of a carboxylic anhydride. The use of aluminum silicate catalyst composed of acid-activated and calcinated natural halloysite instead of the known catalytic silicates as bentonite, zeolite or kaolinite. The new catalyst with a very long lifetime produces polymers having more uniform properties and narrow molecular weight distribution even with a relative impure monomer.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile