| 摘要 |
PURPOSE:To obtain a heat exchanger suppressed in the propagation of bacteria, prevented from the generation of an offensive smell and enhanced in surface hydrophilicity by forming a silicon type film having an antibacterial agent dispersed thereon to the surface of the heat exchanger. CONSTITUTION:A heat exchanger is constituted by forming a chromate film 2 to the surface of a base material 1 composed of aluminum or an alloy thereof and further forming a silicon type film H having an antibacterial agent 4 dispersed therein to said film 2. The core part thus completed in the pretreatment process is immersed in a surface treatment agent being a silicic acid or silicate solution having the antibacterial agent dispersed and compounded therein. Since the propagation of bacteria, fungi and yeast is suppressed when a formed silicon type film is an alkali silicate film, as silicic acid or silicate to be used, sodium silicate, potassium silicate and water glass are especially desired. After the surface treatment agent is uniformly adhered to the surface of the core part, heating/drying treatment is applied to the coated core part to remove a solvent and silicic acid or silicate is gelled to make it possible to form the silicon type film having the antibacterial agent 4 dispersed and compounded therein. As a result, the heat exchanger capable of suppressing the progration of bacteria and capable of keeping hydrophilic effect for a long period of time is obtained. |
