| 摘要 |
PURPOSE:To obtain a heat exchanger having improved wettability with water by using an Al or Cu tube surface-treated with an aq. soln. contg. PVA, a water soluble polymer having a specified compsn. and a water soluble cross- linking agent. CONSTITUTION:A mixed aq. soln. contg. PVA and/or a water soluble deriv. (P1) thereof, a water soluble polymer (P2) made of a homopolymer of a polymerizable monomer having a carboxyl group, a sulfonic acid group, etc., in the molecule and a water soluble cross-linking agent miscible with the polymers P1, P2 is prepd. An Al or Cu tube and Al fins are assembled into a heat exchanger, which is dipped in the prepd. aq. soln. and dried to obtain a heat exchanger having improved wettability with water. |
