Patent ID: 6869677
Filing Date: 2005-03-22
Classification: B05D,C23C,F28F,Y10T

Abstract:
1. An aluminum alloy thermal exchanger comprising: aluminum alloy metal having a surface provided with (a) a first protective layer of chemical conversion coating produced by using a first treatment liquid, the first treatment liquid comprising a water soluble vanadium compound and a fluoro-zirconium complex compound; and (b) a second protective layer of hydrophilic film on the first protective layer, the second protective layer being produced by adding and drying a second treatment liquid, the second treatment liquid comprising an aqueous polyvinyl alcohol polymer having a vinyl alcohol unit of more than 40 mol % and another polymerization unit of less than 60 mol %, polyoxyethylene glycol having a weight average molecular weight of 6,000 to 1,000,000, a vanadium compound, and a zirconium compound, wherein, in the second treatment liquid, the ratio of the weight of zirconium to the weight of vanadium is 40:100 to 350:100.