Method for processing cooling water system

• Main Authors: Nagai Naohiro, Yoshino Takanori, Chiba Ikuko, Nakano Masato, Sano Yuki
• Format: Patent
• Language: English
• Published: 25.10.2016
• 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; COMPOSITIONS BASED THEREON; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; 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; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

A method for treating a cooling water system comprises adding, in a cooling water system having calcium hardness of 250 mg/L or less as CaCO3, a treatment agent containing a (meth)acrylic acid-based copolymer. The (meth)acrylic acid-based copolymer comprises a structural unit (a) derived from a (meth)acrylic acid-based monomer (A) represented by the following general formula (1) and a structural unit (b) derived from a specific (meth)allyl ether-based monomer (B) represented by the following general formula (2), a content of the structural unit (b) is 1 to 15 mol % relative to 100 mol % of structural units derived from all the monomers, a weight average molecular weight of the (meth)acrylic acid-based copolymer is 7,000 to 28,000, and at least one of the main chain terminals of the (meth)acrylic acid-based copolymer is a sulfonic acid group or a salt thereof.