HYDROPHILIZING AGENT, METHOD FOR HYDROPHILIZING AND ALUMINUM OR ALUMINUM ALLOY MATERIAL SUBJECTED TO HYDROPHILIZING

摘要

PROBLEM TO BE SOLVED: To provide a hydrophilizing agent capable of suppressing an unpleasant odor of the hydrophilized film even after long-term use and even after exposure to the presence of an odorous substance and sustaining the hydrophilicity, a method for hydrophilizing and the hydrophilized aluminum or aluminum alloy material and suitably used for a heat exchanger. SOLUTION: This hydrophilizing agent comprises a modified polyvinyl alcohol having a group represented by the formula (I) [wherein, n denotes an integer of 1-500; R<1> denotes hydrogen atom or a 1-4C alkyl group; and R<2> denotes hydrogen atom or methyl group] in the side chain. The hydrophilizing agent is characterized in that the content of the group represented by the formula (I) is 0.01-20 mol% based on the oxygen-containing side chain and the content of the modified polyvinyl alcohol is 0.1-30 mass% based on the hydrophilizing agent.