METHOD FOR TREATING COOLING WATER SYSTEM

• Main Authors: YOSHINO TAKANORI, NAGAI NAOHIRO, NAKANO MASATO, CHIBA IKUKO, SANO YUKI
• Format: Patent
• Language: English
• Published: 16.06.2016
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLICMATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASSC23 AND AT LEAST ONEPROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25; NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

A method for treating a cooling water system includes adding a (meth)acrylic acid-based copolymer to a cooling water system having a part where the calcium hardness of the cooling water is 150 to 300 mg/L and the flow rate of the cooling water is 0.3 to 0.5 m/s, wherein the (meth)acrylic acid-based copolymer has a structural unit (a) derived from a specific (meth)acrylic acid-based monomer (A) and a structural unit (b) derived from a specific (meth)allyl ether-based monomer (B), the content of the structural unit (b) is 15% by mole to 20% by mole relative to 100% by mole of the structural units derived from all the monomers, the weight-average molecular weight of the (meth)acrylic acid-based copolymer is 10,000 to 30,000, and at least one of the main chain terminal groups of the (meth)acrylic acid-based copolymer is a sulfonic acid group or a salt thereof.