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. 24, 2018
Filed:
Apr. 09, 2015
Shin-etsu Chemical Co., Ltd., Tokyo, JP;
SHIN-ETSU CHEMICAL CO., LTD., Tokyo, JP;
Abstract
An object of the present invention is to provide a method for efficiently and highly selectively preparing a composition comprising perfluoropolyether having a hydroxyl group at one terminal at a higher ratio. The present invention provides a method for increasing a ratio of perfluoropolyether having a hydroxyl group at one terminal, relative to a total amount of the perfluoropolyether having a hydroxyl group at one terminal and perfluoropolyether having hydroxyl groups at both terminals in a composition comprising these perfluoropolyethers, wherein the method comprises a step of subjecting the composition to chromatography in which a moving phase is supercritical or subcritical state carbon dioxide of the specific temperature and the specific pressure, and a stationary phase is silica gel to thereby collect a fraction containing the perfluoropolyether having a hydroxyl group at one terminal at a higher ratio. Further, present invention provides for increasing a ratio of perfluoropolyether having a hydroxyl group at one terminal, relative to a total amount of the perfluoropolyether having a hydroxyl group at one terminal, perfluoropolyether having hydroxyl groups at both terminals and perfluoropolyether having no hydroxyl group at any terminal perfluoropolyether, in a composition comprising these perfluoropolyethers, wherein the method comprises a step of subjecting the composition to chromatography in which a moving phase is supercritical or subcritical state carbon dioxide of the specific temperature and the specific pressure, and a stationary phase is silica gel to thereby collect a fraction containing the perfluoropolyether having a hydroxyl group at one terminal at a higher ratio.