| 摘要 |
<P>PROBLEM TO BE SOLVED: To effectively suppress corrosion of a metal member in a cooling water system performing a phosphorus-free zinc treatment. <P>SOLUTION: The following components (A)-(C) are made to be present in the cooling water system performing the phosphorus-free zinc treatment: (A) a copolymer of acrylic acid and a monomer containing a sulfone group, wherein the monomer containing a sulfone group is preferably 2-acrylamide-2-methylpropanesulfonic acid and/or 3-allyloxy-2-hydroxypropane sulfonic acid, the copolymer has a molecular weight of 500-50,000, and the molar ratio of the acrylic acid to the monomer containing a sulfone group is from 7:3 to 9:1; (B) a copolymer of maleic acid and isobutylene, wherein the copolymer preferably has a molecular weight of 10,000-50,000 and the molar ratio of maleic acid to isobutylene is from 5:5 to 8:2; and (C) a zinc compound. <P>COPYRIGHT: (C)2013,JPO&INPIT |
