Metal contamination inhibitor, metal contamination inhibition membrane, method for preventing metal contamination, and method for cleaning product

Patent metadata

Field	Value
Publication number	US-2018257066-A1
Application number	US-201615760507-A
Country	US
Kind code	A1
Filing date	Sep 12, 2016
Priority date	Sep 30, 2015
Publication date	Sep 13, 2018
Grant date	—

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.

First claim

1 . A metal contamination inhibitor to be added to ultrapure water in order to reduce contamination of the ultrapure water with a trace metal contained in the ultrapure water, the metal contamination inhibitor comprising a polymer including an ion-exchange group.

2 . The metal contamination inhibitor according to claim 1 , wherein the polymer is a polymer including either a sulfonic acid group or a quaternary ammonium group.

3 . The metal contamination inhibitor according to claim 1 , wherein the polymer has a molecular weight of 100 thousand or more.

4 . The metal contamination inhibitor according to claim 2 , wherein the polymer is polystyrene sulfonic acid.

5 . The metal contamination inhibitor according to claim 1 , wherein the trace metal is a metal having a valence of two or more.

6 . The metal contamination inhibitor according to claim 1 , the metal contamination inhibitor being added to the ultrapure water at a position upstream of a separation membrane.

7 . A method for preventing metal contamination of a product brought into contact with ultrapure water by a trace metal contained in the ultrapure water, the method comprising adding the metal contamination inhibitor according to claim 1 to the ultrapure water.

8 . The method for preventing metal contamination according to claim 7 , the method further comprising, subsequent to adding the metal contamination inhibitor to the ultrapure water, passing the water through a module including a separation membrane, and bringing water passed through the membrane into contact with the product.

9 . A method for cleaning a product, the method comprising adding the metal contamination inhibitor according to claim 1 to ultrapure water, and cleaning a product with the ultrapure water.

10 . The method for cleaning a product according to claim 9 , the method further comprising, subsequent to adding the metal contamination inhibitor to the ultrapure water, passing the water through a module including a separation membrane, and cleaning the product with water passed through the membrane.

11 . A metal contamination inhibition membrane comprising the metal contamination inhibitor according to claim 1 , the metal contamination inhibitor being deposited or fixed on the metal contamination inhibition membrane.

Assignees

• Kurita Water Ind Ltd

Inventors

• Morita Hiroshi
• Kato Toshimasa
• Hoshi Shigeyuki

Classifications

• H10P72/0416

  with the semiconductor substrates being dipped in baths or vessels · CPC title

• H10P70/15

  by wet cleaning only (H10P70/52 takes precedence) · CPC title

• B01J41/04

  Processes using organic exchangers · CPC title

• B01J47/12

  characterised by the use of ion-exchange material in the form of ribbons, filaments, fibres or sheets, e.g. membranes (electrodialysis or electro-osmosis B01D61/42) · CPC title

• B01J39/04 Primary

  Processes using organic exchangers · CPC title