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:
Jan. 16, 2018
Filed:
Mar. 15, 2016
Tokyo Ohka Kogyo Co., Ltd., Kawasaki-shi, JP;
TOKYO OHKA KOGYO CO., LTD., Kawasaki-shi, JP;
Abstract
A process removes metal impurities from an untreated chemical liquid, which includes a silylating agent. The process includes providing a strongly acidic cation-exchange resin in which a cation-exchange group is immobilized to a resin membrane or an integral structure of a particle-removing membrane and an ion exchange resin membrane in which a strongly acidic cation-exchange resin has been chemically introduced onto surfaces of pores in a porous resin. The wettability of the ion exchange resin membrane is thereafter improved by contacting the ion-exchange resin membrane with an organic solvent. The metal impurities are then removed from the untreated chemical liquid by passing the untreated chemical liquid through the ion-exchange resin membrane.