HEAT EXCHANGER MADE OF ALUMINUM ALLOY

摘要

PROBLEM TO BE SOLVED: To provide an Al alloy heat exchanger formed with films which do not substantially generate malodors, can impart excellent corrosion resistance and hydrophilicity and do not contain hazardous chromium. SOLUTION: This heat exchanger has a base material which includes tubes and fins constituted by forming of Al alloys, a first protective layer which is formed thereon by using a treating liquid containing a water-soluble V compound (a) and a fluorozirconium complex compound (b) and a second protective layer which is formed on the first protective layer and consists of the hydrophilic film formed by application and drying of a treating liquid which contains polyvinyl alcohol aqueous polymer (c) having >=40 mol% vinyl alcohol unit and 0 to <=60 mol% at least one polyvinyl alcohol addition polymerization unit different from the vinyl alcohol unit, a polyoxyethylene glycol (d) having a weight average molecular weight of 6,000 to 1,000,000, a V compound (e) and a Zr compound (f) and in which the weight ratio of Zr in the Zr compound (f) to V in the V compound (e) is 40-350%.