| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a technique capable of preventing scale with respect to a metal pipe surface constituting cooling water piping etc. in a more versatile approach. <P>SOLUTION: When a metal member is a copper pipe for a heat exchanger in which cooling water of pH 7-8 is made to flow at 30-40°C, a film mainly composed of at least one type of a material selected from zinc oxide and aluminum oxide is formed on the surface of the copper pipe. Due to this, since zeta potential of calcium carbonate and zeta potential of the film surface assume the same sign, the scale prevention effect can be extremely enhanced. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
