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.

Date of Patent:
Mar. 08, 1994

Filed:

Nov. 22, 1991
Applicant:
Inventors:

Takamitsu Morita, Yokohama, JP;

Junya Watanabe, Tokyo, JP;

Toyokazu Sugawara, Sagamihara, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C02F / ;
U.S. Cl.
CPC ...
210638 ; 210664 ; 210669 ; 210686 ; 210900 ;
Abstract

A method for preparing an ultrapure water, from which impurities including inorganic salts, organic substances, fine particles and microorganisms are removed, by treatment including an ion exchange treatment, which comprises using an ion exchange resin comprising a copolymer of a polyvinyl compound and a monovinyl aromatic compound which may contain a monovinyl aliphatic compound, as the matrix, at least in a mixed bed ion exchange treatment of the ion exchange treatment, said ion exchange resin used comprising at least a regenerated form ion exchange resin A eluting an organic compound of a molecular weight of less than 3,000 but substantially not eluting an organic compound of a molecular weight of not less than 3,000 when dipped in a hot water at 50.degree. C. for 7 days.


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