Heat exchanger

Abstract

A surface polyaniline layer comprising a polyaniline and/or a derivative thereof capable of generating active oxygen or hydrogen peroxide upon the reaction with the water component in external air that comes in contact therewith, is formed on at least a portion of the outermost surface of a base body constituting tubes and/or fins, wherein a benzenoid/quinoid ratio in the surface polyaniline layer (defined as a ratio of an absorbancy of the benzenoid structure to an absorbancy of the quinoid structure in the polyaniline and/or the derivative thereof) is in a range of about 0.5 to about 3.0.

1 . A heat exchanger equipped with at least one tube having at least one fin, wherein:
 said at least one tube and/or said at least one fin being composed of at least a base body and a surface film formed on at least a portion of an uppermost surface of the base body,   the surface film is a surface polyaniline layer composed of a polyaniline and/or a derivative thereof capable of generating active oxygen or hydrogen peroxide by reacting with a water component in external air that comes in contact therewith, and   a ratio of benzenoid to quinoid in the surface polyaniline layer is in a range of 0.5 to 3.0, which is defined as a ratio of an absorbancy of a benzenoid structure to an absorbency of a quinoid structure in the polyaniline and/or in the derivative thereof.   
   
   
       2 . The heat exchanger according to  claim 1 , wherein the ratio of benzenoid to quinoid is in a range of 1.0 to 2.0. 
   
   
       3 . The heat exchanger according to  claim 1 , wherein the surface polyaniline layer is formed on the entire uppermost surface of the base body. 
   
   
       4 . The heat exchanger according to  claim 1 , wherein the surface polyaniline layer further has at least one kind of hydrophilic functional group introduced therein. 
   
   
       5 . The heat exchanger according to  claim 4 , wherein said at least one kind of hydrophilic functional group is selected from the group consisting of a primary amino group, a secondary amino group, a tertiary amino group, an ammonium group, a nitric acid group, a carboxyl group, a sulfonic acid group and a hydroxyl group. 
   
   
       6 . The heat exchanger according to  claim 4 , wherein said at least one kind of hydrophilic functional group is one that stems from a binder used for forming the surface polyaniline layer from the polyaniline and/or the derivative thereof. 
   
   
       7 . The heat exchanger according to  claim 6 , wherein said at least one kind of hydrophilic functional group is one that has been introduced in the binder in advance. 
   
   
       8 . The heat exchanger according to  claim 1 , wherein the base bodies of said at least one tube and/or said at least one fin are the ones which have been formed by molding a metallic material. 
   
   
       9 . The heat exchanger according to  claim 8 , wherein the metallic material is composed of a metallic material containing aluminum. 
   
   
       10 . The heat exchanger according to  claim 1 , wherein the base bodies of said at least one tube and/or said at least one fin are composed of a composite body of at least two layers of metallic materials, wherein an amount of a metallic material having a higher oxidation-reduction potential increases from an upper metallic material layer toward a lower metallic material layer. 
   
   
       11 . The heat exchanger according to  claim 10 , wherein the base bodies of said at least one tube and/or said at least one fin are composed of a composite body of two layers of metallic materials, wherein a lower metallic material layer of the composite body is composed of an aluminum (Al) alloy, and an upper metallic material layer of the composite body is composed of a zinc (Zn)-containing metallic material. 
   
   
       12 . The heat exchanger according to  claim 11 , wherein the lower metallic material layer is composed of an Al—Mn based alloy, and the upper metallic material layer is composed of a metallic material containing silicon (Si) in addition to zinc. 
   
   
       13 . The heat exchanger according to  claim 12 , wherein the upper metallic material is composed of an aluminum alloy containing aluminum (Al) and impurities, in addition to zinc and silicon. 
   
   
       14 . The heat exchanger according to  claim 1 , wherein the surface polyaniline layer further contains a dopant. 
   
   
       15 . The heat exchanger according to  claim 14 , wherein the dopant is adhered to the polyaniline and/or the derivative thereof due to an electrostatic interaction. 
   
   
       16 . The heat exchanger according to  claim 1 , wherein said at least one tube and/or said at least one fin further have at least one interlayered intermediate layer between the base body thereof and the surface polyaniline layer. 
   
   
       17 . The heat exchanger according to  claim 16 , wherein said at least one interlayered intermediate layer is composed of a nonmetallic material. 
   
   
       18 . The heat exchanger according to  claim 16 , wherein said at least one interlayered intermediate layer is selected from the group consisting of an insulating film, an antioxidizing film, and a film composed of a nonmetallic material having a higher oxidation-reduction potential than that of the polyailine and/or the derivative thereof. 
   
   
       19 . The heat exchanger according to  claim 1 , further comprising structure-converting means for converting the benzenoid structure constituting the polyaniline and/or the derivative thereof into the quinoid structure, or for converting the quinoid structure into the benzenoid structure, in order to bring the ratio of benzenoid to quinoid back into a preset range of 0.5 to 3.0, when the ratio of benzenoid to quinoid has fallen outside the preset range in the surface polyaniline layer. 
   
   
       20 . The heat exchanger according to  claim 19 , wherein the structure-converting means is voltage-applying means, wherein electrons are removed from the surface polyaniline layer, by arranging an opposite electrode composed of another substrate to the heat exchanger, and flowing a current between the heat exchanger and the opposite electrode via the voltage-applying means. 
   
   
       21 . The heat exchanger according to  claim 20 , wherein the structure-converting means is the voltage applying means with a means for changing the direction of current, and a current is flowed between the heat exchanger and the opposite electrode by reversing the direction of current, when the ratio of benzenoid to quinoid has become greater than the preset range of 0.5 to 3.0. 
   
   
       22 . The heat exchanger according to  claim 19 , further comprising timer means for controlling a time period in which the current is reversely flowed by the means for changing the direction of current. 
   
   
       23 . The heat exchanger according to  claim 19 , further comprising absorbancy-ratio detecting means for detecting the ratio of benzenoid to quinoid in the surface polyaniline layer. 
   
   
       24 . The heat exchanger according to  claim 20 , wherein when a current is flowed between the heat exchanger and the opposite electrode, the flow of current is controlled depending upon an amount of electric current that flows or upon an amount of electric charge. 
   
   
       25 . The heat exchanger according to  claim 20 , further comprising means for measuring the amount of current flow or the amount of electric charge thereby to control the time period for flowing the electric current. 
   
   
       26 . The heat exchanger according to  claim 1 , wherein the surface polyaniline layer is further formed also on the uppermost surface of said at least one tube. 
   
   
       27 . The heat exchanger according to  claim 1 , which is used for a vehicle air conditioner.