Patent ID: 9739544
Date: 2017-08-22
CPC Classifications: B05D,B23K,C23C,F28F

Claim:
1. A surface treatment method for an aluminum heat exchanger, comprising: (a) a step of forming a chemical conversion film on a surface of the aluminum heat exchanger using a chemical conversion treatment agent; (b) a step of bringing the aluminum heat exchanger on which the chemical conversion film was formed on the surface in the step (a) into contact with a hydrophilization treatment agent containing a hydrophilic resin; and (c) a step of forming a hydrophilized film on the surface by baking the aluminum heat exchanger that was contact treated in the step (b), wherein the chemical conversion treatment agent used in the step (a) contains both zirconium and titanium, wherein a content thereof is 10 to 2,500 ppm by mass in total, contains vanadium, wherein a content thereof is 100 to 500 ppm by mass, contains a metal stabilizer, wherein a content thereof is 10 to 2,000 ppm by mass, and has a pH of 3 to 5.