公开(公告)号：US20180257066A1

公开(公告)日：2018-09-13

申请号：US15760507

申请日：2016-09-12

Applicant: KURITA WATER INDUSTRIES LTD.

Inventor： Hiroshi MORITA ,  Toshimasa KATO ,  Shigeyuki HOSHI

IPC: B01J39/04 ,  B01J41/04 ,  B01J47/12 ,  C02F1/42 ,  C02F1/62

CPC classification number: B01J39/04 ,  B01J41/04 ,  B01J47/12 ,  C02F1/42 ,  C02F1/444 ,  C02F1/62 ,  C02F2101/20 ,  C02F2103/04 ,  H01L21/02052 ,  H01L21/67057

Abstract: The present invention reduces adhesion of trace metals in ultrapure water for cleaning products, and inhibits the metal contamination of an object to be cleaned. Provided is a metal contamination inhibitor that contains a polymer having an ion-exchange group, such as a polystyrene sulfonate having a molecular weight of at least 100,000. Trace metals in ultrapure water are adsorbed through an ion-exchange reaction of the polymer having the ion-exchange group, and can thus be inhibited from adhering to products. Also provided is a method for cleaning a product with ultrapure water to which the metal contamination inhibitor has been added. Preferably, the ultrapure water to which the metal contamination inhibitor has been added flows through a separation membrane module, and the products are cleaned with permeated water.

公开(公告)号：US20190059380A1

公开(公告)日：2019-02-28

申请号：US15773623

申请日：2016-03-28

Applicant: KURITA WATER INDUSTRIES LTD.

Inventor： Takashi IYASU ,  Yasushi MURANO ,  Toshimasa KATO

IPC: A01N43/80 ,  A01N25/22 ,  C02F1/50 ,  C02F1/76

Abstract: The present invention provides a method for suppressing a decrease in the concentration of an isothiazoline compound, wherein even if an addition concentration of the isothiazoline compound used as an antibacterial agent is low in a water system, the decrease in the concentration thereof can be suppressed so that the residual rate thereof after 24 hours can be raised. The method is carried out in a manner wherein to a water system, an isothiazoline compound is fed with an addition concentration of 0.2 mg/L or more and less than 1 mg/L, and a combined chlorine agent consisting of a chlorine stabilizer and a chlorine-based oxidant is added so as to maintain a concentration thereof at 0.3 mg/L as Cl2 or more and 6 mg/L as Cl2 or less therein.