| 摘要 |
A treatment method for hydrophilicity for a heat exchanger which can maintain the deodorizing property and hydrohilicity even after a long-time use, and a heat exchanger thus treated for hydrophilicity by said method are provided. After a previous acidic washing treatment, a heat exchanger is subjected to a chemical transformation treatment to form a chemical conversion coating film using a chromium chromate treatment agent, chromium phosphate treatment agent, or treatment agent of zirconium series, followed by a treatment for hydrophilicity using a treatment agent for hydrophilicity, which contains silica particulates and polymer of vinyl alcohol series in aqueous medium in a weight ratio 30:70~70:30 and in tot al content of 1~25 weight percent, and in which said silica particulates are coated with said polymer of vinyl alcohol series, and dispersed as coated particles of the average particle diameter of 5~1000 nm in aqueous medium, to form the coating film so as to amount to 1~3 g/m2.
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