HYDROPHILIC COATING FILM COVERING METHOD OF ALUMINUM FIN MATERIAL, ALUMINUM FIN MATERIAL AND ALUMINUM HEAT EXCHANGER

摘要

PROBLEM TO BE SOLVED: To provide a surface treatment method of a heat exchanger superior in adhesion of a hydrophilic coating film and a metallic surface in a state of adhering moisture, superior in hydrophilic persistence in a state of adhering pollutant and capable of forming the hydrophilic coating film while not causing the problem of odor when used in the heat exchanger, an aluminum fin material of forming the hydrophilic coating film on a surface of a fin by the method and an aluminum heat exchanger formed by using the aluminum fin material.SOLUTION: The metallic surface is covered with the hydrophilic coating film by using a hydrophilic treatment agent including a hydrophilic resin and a cross-linking particulate, and including resin of at least one kind selected from a specific (meth) acrylic resin, polyvinyl alcohol, polyethylene oxide and polyethylene glycol as the hydrophilic resin.