JP2003088748A - Production method for polyaniline film and heat exchanger having polyaniline film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method for a polyaniline film whereby a desired film formation state can be easily realized. SOLUTION: In this method for producing a polyaniline film, a substrate member is coated with a solution containing dissolved polyaniline and dried. The range of concentration of polyaniline in the solution is set wider by dissolving polyaniline in a solvent kept at 30 deg.C-80 deg.C than in the case when polyaniline is dissolved in the solvent kept at 20 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is manufactured by a method for manufacturing a polyaniline film for forming a polyaniline film on a film-formed member made of metal or the like for the purpose of deodorization, rust prevention, antifouling and the like, and a manufacturing method thereof. A heat exchanger having a polyaniline membrane.

[0002]

2. Description of the Related Art Conventionally, an active oxygen generator using polyaniline which releases active oxygen for sterilization and deodorization (Japanese Patent Application Laid-Open No. 20-29200).
01-70426) and a film containing a polyaniline compound formed on a metal plate to decompose oil and dirt due to photocatalytic properties (JP-A-11-256351).

[0003]

However, when a polyaniline film exhibiting such characteristics is formed on a member to be film-formed, the qualitative characteristics of the polyaniline film such as the coverage, the film thickness, and the release characteristics of active oxygen. Conventionally, there has been no manufacturing method for controlling the quantitative film formation state.

In view of the above problems, the present invention provides a method for producing a polyaniline film capable of easily realizing a desired film formation state and a heat exchanger having the polyaniline film produced by such a production method. The purpose is to do.

[0005]

Means for Solving the Problems The present inventors have focused on a relatively easy manufacturing method for manufacturing a polyaniline film by applying it on the surface of a member to be film-formed and drying it. An experiment was conducted to determine whether the film formation state of the polyaniline film could be controlled by adjusting the concentration.

As a result, when the liquid temperature of the solvent is room temperature (20 ° C.), the amount of polyaniline dissolved in the solvent, that is, the concentration of polyaniline in the coating liquid is small, and when it is used in a heat exchanger or the like, it is practically used. It has been found that it is difficult to achieve sufficient coverage, film thickness, active oxygen release characteristics, and the like.

Therefore, the temperature of the solvent should be heated so that the polyaniline concentration in the coating liquid should be higher than that when the temperature of the solvent is 20 ° C. A study was conducted to find the temperature. The present invention was created based on the examination results.

That is, according to the first aspect of the invention, there is provided a production method for producing a polyaniline film by applying a solution of polyaniline dissolved in a solvent onto the surface of a member to be film-formed and drying the solution. It is characterized in that the concentration range of polyaniline in the solvent is set wider than when the liquid temperature of the solvent is 20 ° C. by dissolving the polyaniline in a state where the solvent is heated in the range of 30 ° C. to 80 ° C. .

By heating the solvent so that the concentration range of polyaniline in the solvent is set wider than that when the liquid temperature of the solvent is 20 ° C., the selection range of the desired polyaniline concentration is expanded to a higher concentration. The characteristics such as the coverage, the film thickness, the weight, the amount of active oxygen released, etc. of the polyaniline film thus formed can be controlled in a wider range.

Here, when the liquid temperature of the solvent is 30 ° C. or higher, the effect of broadening the concentration range of the polyaniline more than when the liquid temperature of the solvent is 20 ° C. appears favorably. Further, when the liquid temperature of the solvent is higher than 80 ° C., the polyaniline solution (coating liquid) is likely to gel. Therefore, the solvent is kept heated in the range of 30 ° C to 80 ° C.

As described above, by appropriately selecting the polyaniline concentration in the heated solvent and applying the heated polyaniline solution to the member to be film-formed, a desired film-forming state can be easily realized. A method for manufacturing a polyaniline film can be provided.

Further, it is preferable that the solvent is heated in the range of 40 ° C. to 60 ° C. as in the second aspect of the invention. This is because the effect of expanding the concentration range of polyaniline as compared with the case where the liquid temperature of the solvent is 20 ° C is more suitably exhibited when the liquid temperature of the solvent is 40 ° C or higher, and the liquid temperature of the solvent is higher than 60 ° C. This is because the solvent may evaporate, making it difficult to adjust the concentration.

Further, as in the invention described in claim 3, N-methyl-2-pyrrolidone can be used as the solvent.

The invention according to claim 4 is characterized in that the coverage of the polyaniline film is controlled by controlling the concentration of polyaniline in the solvent. Specifically, a desired coverage can be obtained by obtaining a correlation between the polyaniline concentration and the coverage of the polyaniline film and controlling the polyaniline concentration based on this correlation.

In particular, according to the fifth aspect of the invention, by setting the coverage of the polyaniline film to 97% or more,
It is possible to prevent deterioration of the characteristics of the film-forming member such as a heat exchanger and deterioration of the polyaniline film. Like this method,
Unless the solvent is heated, it is impossible to achieve the coverage rate of 97% or more.

The invention according to claim 6 is characterized in that the amount of active oxygen released from the polyaniline film is controlled by controlling the concentration of polyaniline in the solvent. The invention according to claim 7 is characterized in that the film thickness of the polyaniline film is controlled by controlling the concentration of polyaniline in the solvent. Furthermore, the invention according to claim 8 is characterized in that the weight of the polyaniline film is controlled by controlling the concentration of polyaniline in the solvent.

Also in these inventions, specifically, the correlation between the polyaniline concentration and the amount of active oxygen released from the polyaniline film, the film thickness and the weight is obtained in advance, and the polyaniline concentration can be controlled based on this correlation. For example, a film formation state having a desired state in each characteristic can be realized.

Further, as in the invention described in claims 9 and 10, the film-forming member is made of a material having free electrons (metal, semiconductor, etc.), specifically, aluminum (Al ) Can be used as the main component.

If the film-forming member is made of a material having free electrons, the polyaniline film can properly exhibit the function of extracting electrons from the underlying film-forming member to release active oxygen. is there.

According to the invention described in claim 11,
A heat exchanger comprising a polyaniline film produced by the production method according to claim 9 or 10 in a heat exchange section. Specifically, as in the invention described in claim 12, it is possible to provide a heat exchanger for a vehicle mounted on a vehicle.

The reference numerals in parentheses for each means described above are examples showing the correspondence with the specific means described in the embodiments described later.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention shown in the drawings will be described. FIG. 1 is a process diagram showing a method for manufacturing a polyaniline film according to an embodiment of the present invention.

To explain the outline of the present manufacturing method, first, in the solution preparation step, a solution (polyaniline solution, coating solution) in which soluble polyaniline is dissolved in a solvent such as an organic solvent is prepared. At this time, by dissolving the polyaniline in a state where the solvent is heated in the range of 30 ° C. to 80 ° C., the concentration range of the polyaniline in the solvent is set wider than when the liquid temperature of the solvent is 20 ° C.

Next, in the dip coating step, a film-forming member such as a fin for a heat exchanger made of Al is dipped in the polyaniline solution maintained in the heated state, and the polyaniline solution is applied to the surface of the film-forming member. Apply. Subsequently, in the liquid removing step, the excess polyaniline solution is shaken off from the surface of the film formation target member by rotating the film formation target member or the like.

Subsequently, in the drying step, the solvent is evaporated from the coating film on the surface of the member to be film-formed by heat treatment or the like at a temperature at which polyaniline is not crosslinked. In this way, a polyaniline film is formed on the surface of the film formation member.

According to such a manufacturing method, the solvent is heated so that the concentration range of the polyaniline in the solvent is set wider than that when the liquid temperature of the solvent is 20 ° C. Is spread to a higher concentration, the coverage of the polyaniline film formed thereby,
It is possible to control the characteristics such as the film thickness, the weight, and the amount of active oxygen released in a wider range.

Next, the present manufacturing method will be described in more detail with reference to specific examples, although not limited thereto.
The chemical structure of polyaniline used in this example is shown in the following chemical formulas 1 and 2. Chemical formula 1 is a conductive type doped polyaniline, and chemical formula 2 is a non-conductive dedoped type polyaniline.

[0028]

[Chemical 1]

[0029]

[Chemical 2] Here, in the above Chemical Formula 1 or 2, A represents an anion (eg, chlorine ion), n represents an integer in the range of 2 or more and 500 or less, and x and y are x + y = 1 and 0 ≦.
It is a number that satisfies y ≦ 0.5.

In this example, N-methyl- was used as the solvent.
Using 2-pyrrolidone (NMP), the heating temperature of the solvent is
The temperatures were 60 ° C., 40 ° C. and 20 ° C., respectively. Further, the polyaniline concentration in the solution is set to% by weight, but hereinafter, it is simply shown as%.

[Concentration control] First, 40 ml of NMP
(ML), placed in a beaker with a lid, and placed in three types of thermostats set to the solvent heating temperature while stirring. Next, in the constant temperature bath, dedoped polyaniline synthesized by the chemical polymerization method (see the above chemical formula 2) was put into the solvent little by little and dissolved.

Thereafter, for about 3 days, polyaniline was charged and the weight% concentration thereof was measured in each thermostat until the polyaniline concentration remained unchanged (until dissolution was saturated). As a result, the maximum solubility (saturation concentration) of polyaniline was 1.8% at 20 ° C and 5.2% at 40 ° C.
% And 6.5% at 60 ° C.

FIG. 2 is a graph showing changes in the maximum solubility (%) of polyaniline with respect to the heating temperature of the solvent (solvent temperature of the solvent, ° C) in the solution prepared by this procedure.
As shown in FIG. 2, the maximum solubility of polyaniline was 40 ° C. and 60 ° C. as compared with the case where the liquid temperature of the solvent was 20 ° C. (normal temperature).
It rises dramatically as the temperature rises to ℃.

Next, these polyaniline solutions having maximum solubilities were further diluted with NMP to set various polyaniline concentration conditions. The target value for the set concentration is a liquid temperature of 60 ° C.
And 40 ° C., 5.2%, 4.3%, 3.4%,
2.0%, and at a liquid temperature of 20 ° C., 1.8%, 1.0
% And 0.5%. It should be noted that due to an error in preparation, these target value densities are slightly different from the actual densities in each graph described later.

The concentration conditions were set in the same manner as when dissolving the polyaniline in NMP as described above, in order to maintain the liquid temperature of each solvent, the concentration was adjusted in a constant temperature bath, and the polyaniline concentration was grasped by the weight% concentration. . In this way, polyaniline solutions (coating solutions) having different liquid temperatures and polyaniline concentrations were prepared (solution preparing step).

Next, 0.8 g of a heat exchanger fin mainly made of Al (aluminum) was cut out as a member to be film-formed, degreased with a surfactant, and then dip-coated in each polyaniline solution to prepare a solution. Cut and dried. The liquid is
The rotation was performed at 1 rotation / second for about 30 seconds, and the drying was performed at 140 ° C., which is a high temperature in which polyaniline is not crosslinked, for 20 minutes. Thus, the polyaniline film formed on the fin surface was formed under each concentration condition.

By the way, as can be seen from the approximate line in the graph of FIG. 2, when the liquid temperature of the solvent is 30 ° C. or higher, the effect of broadening the polyaniline concentration range is better than when the liquid temperature of the solvent is 20 ° C. appear. Further, according to the study by the present inventors, when the liquid temperature of the solvent (NMP) was higher than 80 ° C., the polyaniline solution was gelated, and it was difficult to manufacture the polyaniline film.

Therefore, in order to set the concentration range of polyaniline in the solvent to be wider than that when the liquid temperature of the solvent is 20 ° C., the solvent should be heated within the range of 30 ° C. to 80 ° C. Become. In FIG. 2, 30 ° C. to 80 ° C. is set as the optimum temperature range and the allowable range, and the low temperature of less than 30 ° C. 8
A temperature higher than 0 ° C. is shown as an impossible region.

As can be seen from FIG. 2, the effect of broadening the concentration range of polyaniline as compared with the case where the liquid temperature of the solvent is 20 ° C. is more suitably exhibited when the liquid temperature of the solvent is 40 ° C. or higher. Further, if the liquid temperature of the solvent is higher than 60 ° C., the solvent evaporates and it becomes difficult to adjust the concentration. Therefore, more preferably, the heating temperature (liquid temperature) of the solvent is in the range of 40 ° C. or higher and 60 ° C. or lower (optimum temperature range).

Next, with respect to the polyaniline film on the surface of the fin (member to be film-formed) formed under various concentration conditions in this example, the characteristics such as the coverage, the amount of active oxygen released, the film thickness, and the weight were examined.

[Coverage] Regarding the polyaniline film formed on the fin surface as described above, the coverage was measured,
evaluated. The coverage can be defined by the film formation area of the polyaniline film on the fin (member to be film-formed), and is represented by the expression: coverage = (film formation area / total area) × 100 (%).

In this example, the adhesion image of the polyaniline film on the Al fin (member to be film-formed) was captured as electronic data by an optical microscope, binarized by image processing software (white: aluminum, black: polyaniline), and then, The above coverage was calculated. That is, the calculated coverage is: coverage = {black area / (black + white area)} × 100 (%).

FIG. 3 is a graph showing the results of this measurement, and is a graph showing the coverage (%) with respect to the polyaniline concentration (%) at each heating temperature of the solvent (solvent temperature). Maximum solubility of polyaniline at room temperature (20 ° C) 1.8
%, The coverage of the polyaniline film on the fin (member to be film-formed) was about 92% to 93%.

On the other hand, the liquid temperature of the solvent is 40
When the temperature was 60 ° C. and 60 ° C., the coverage could be improved to 97% or more in all regions where the polyaniline concentration was 2% or more. Further, when the polyaniline concentration is further increased, the coverage is infinitely close to 100%.

When forming a polyaniline film on a heat exchanger, by ensuring a coverage of the polyaniline film of 97% or more, it is possible to prevent deterioration of heat exchange characteristics and deterioration of the polyaniline film and metallic materials. You can That is, by using a polyaniline solution that achieves a high polyaniline concentration by heating, the polyaniline film can be formed with a high coverage and a high density, defects can be reduced, and the quality of the film can be improved.

As described above, in controlling the coverage of the polyaniline film by controlling the concentration of polyaniline in the solvent, the correlation between the polyaniline concentration and the coverage of the polyaniline film as shown in FIG. 3 is obtained. Then, if the polyaniline concentration is arbitrarily controlled based on this correlation, it is possible to easily realize a film formation state with a desired coverage.

[Amount of Active Oxygen Released] The amount of active oxygen released was measured and evaluated for the polyaniline film formed on the surface of the fin (member to be film-formed) as described above. Polyaniline releases active oxygen when adsorbing water (Japanese Patent Laid-Open No. 2001-70426).

The polyaniline film formed on the member to be formed is
Either the doped type (see Chemical Formula 1) or the undoped type (see Chemical Formula 2) may be used, but the doped type releases a larger amount of active oxygen when wet with water. Therefore, in the case of the undoped type, it is immersed in an acidic liquid such as hydrochloric acid (HCl) to form a doped polyaniline film.

In this example, a de-doped type polyaniline film formed on a fin was obtained, converted to a doped type in the following manner, and the amount of active oxygen released was measured. The amount of active oxygen was measured by measuring the electron spin of active oxygen by the Fenton reaction.

25 Al fins with polyaniline film
mg cut-out, 1 mol / L (mol / liter) HC
After immersing in 1 l for 1 minute, it was washed with water and dried at 60 ° C. for 20 minutes to complete the dope. Next, the Al fin was immersed in 1 ml (ml) of H ₂ O and left for 3 hours.

Thereafter, 500 μl (microliter) of this H ₂ O was sampled, and to this 500 μl of H ₂ O was added a ₂₀₀ mmol / L phthalate buffer solution (pH with hydrochloric acid).
Was adjusted to 2.8) and 10 ^-2 mmol / L of Fe was added.
50 μl of the solution containing Cl ₃ and 5,5-Dimeth
yl-1-Pyroline-N-Oxide (DMP
O) and 3.75 μl were added and stirred, and then left for 90 minutes (Fenton reaction).

Then, 150 μl of this reaction solution was sampled in an aqueous solution cell, and the electron spin of active oxygen was measured by an electron spin resonance (ESR) device. Then, the electron spin number was converted into the active oxygen concentration and evaluated.

FIG. 4 is a graph showing the results of this measurement. The amount of active oxygen released from the polyaniline film (active oxygen generation amount, unit: ppm) with respect to the polyaniline concentration (%) at each heating temperature of the solvent (solvent temperature). ) Is a graph showing. At each solvent temperature, the amount of active oxygen generated increased with the increase in polyaniline concentration.

As described above, in controlling the active oxygen generation amount by controlling the polyaniline concentration in the solvent, the correlation between the polyaniline concentration and the active oxygen generation amount as shown in FIG. By arbitrarily controlling the polyaniline concentration based on this correlation, it is possible to easily realize a film formation state with a desired active oxygen generation amount.

In this example, a fin made of a material containing aluminum (Al) as a main component is used as the film-forming member. Not limited to this Al, as long as the film formation member is made of a material having free electrons (metal, semiconductor, etc.),
The polyaniline film can appropriately exhibit the function of extracting electrons from the underlying film-forming member to release active oxygen.

[Film Thickness] The film thickness of the polyaniline film formed on the surface of the fin (member to be film-formed) as described above was measured and evaluated.

In this example, a cross-sectional image scanned in the height direction was obtained with an optical microscope and evaluated. Since the fins on which the polyaniline film is formed are uniformly formed, it is difficult to measure because the aluminum surface of the fins is not exposed, so only the polyaniline film is partially peeled off using an adhesive tape, with or without the polyaniline film. The cross-sectional height of the boundary surface was measured as the film thickness.

FIG. 5 is a graph showing the results of this measurement, and is a graph showing the film thickness (μm) of the polyaniline film against the polyaniline concentration (%) at each heating temperature of the solvent (solvent temperature). At each solvent temperature, the film thickness also increased as the polyaniline concentration increased.

As described above, in controlling the film thickness of polyaniline by controlling the concentration of polyaniline in the solvent, the correlation between the polyaniline concentration and the film thickness as shown in FIG. By arbitrarily controlling the polyaniline concentration based on the relationship, it is possible to easily realize a film formation state having a desired film thickness.

[Weight] The polyaniline film formed on the surface of the fin (member to be film-formed) as described above was weighed and evaluated. FIG. 6 is a graph showing the weight (g) of the polyaniline film with respect to the polyaniline concentration (%) at each heating temperature of the solvent (solvent temperature).

In FIG. 6, the film weight is the weight (adhesion amount) of the polyaniline film adhered to 1 g of the fin (member to be film-formed). At each solvent temperature, the film weight also increased with the increase of polyaniline concentration.

As described above, in controlling the film thickness of polyaniline by controlling the concentration of polyaniline in the solvent, the correlation between the polyaniline concentration and the film thickness as shown in FIG. By arbitrarily controlling the polyaniline concentration based on the relationship, it is possible to easily realize a film-forming state having a desired weight.

As described above, according to the present embodiment, the concentration of polyaniline in the heated solvent is appropriately selected, and the heated solvent is applied to the film-forming member to form a desired film. It is possible to provide a method for producing a polyaniline film that can easily realize a state.

In the above manufacturing method, the example in which the temperature of the solvent is maintained by performing solution preparation and dip coating in the thermostatic bath has been described. However, the solution preparation part and the dip coating part are provided in separate thermostatic baths. It may be provided in the (heat-retaining part) so that the solution can be supplied from the solution preparation part to the dip coating part while keeping the temperature.

Further, since the solution shaken off by the liquid cutting can be used again for the dip coating, there is no problem even if the dipping coating process and the liquid cutting process are performed in one constant temperature bath. . Further, the method of draining or drying may be any method.

The polyaniline film produced by the production method of the present embodiment is used as a heat exchanger for automobiles mounted on automobiles, general commercial or household heat exchangers, and also for deodorization, rust prevention and protection. Any member can be arbitrarily applied as long as it is a member that needs to form a film of polyaniline for the purpose of contamination.

As an application example, FIG. 7 is a perspective view showing a heat exchanger 21 for an automobile air conditioner having a polyaniline film manufactured by the manufacturing method of this embodiment in a heat exchange section. The heat exchanger 21 is installed in the cooling unit case of an automobile air conditioner (not shown) with the vertical direction in the drawing up and down.

A pipe joint 22 is arranged on one end side of the heat exchanger 21 in the left-right direction. In addition, a large number of tubes 23 are arranged in parallel, and a heat exchanging section 24 for exchanging heat between the refrigerant flowing through the refrigerant passages inside the tubes 23 and the air flowing outside the tubes 23 is provided.

In the heat exchanger 24, the radiation fins 25 are joined to the gaps between the outer surfaces of the adjacent tubes 23 to increase the heat transfer area on the air side. The upper and lower parts of the tube 23 are in communication with the tank 26, and the refrigerant circulates through the tube 23 and the tank 26, and flows into and out of the heat exchanger 21 via the pipe joint 22. Note that these parts are made of Al material.

A polyaniline film 28 is formed on the surface of the heat exchange section (member to be film-formed in the present invention) 4 in the heat exchanger 21 having such a structure. The formation is based on the above-described manufacturing method, and the polyaniline concentration is controlled so that at least one of the desired coverage (97% or more), active oxygen generation amount, film thickness, and weight is satisfied. went.

When the air conditioner is in operation, the air containing the water vapor 27 shown by the arrow A in the drawing passes through the heat exchanger 21 from the front of the vehicle. At this time, when the heat exchange section 24 and this air come into contact with each other, the dew point of the air is lowered, and water vapor in the air becomes water droplets and adheres to the surface of the heat exchange section 24 as condensed water.

At this time, when the condensed water attached to the surface of the heat exchanger 24 and the polyaniline film 28 come into contact with each other, the polyaniline reduces dissolved oxygen (O ₂ ) in the condensed water (provides electrons to the dissolved oxygen) and activates. It becomes oxygen. Then, this active oxygen decomposes odorous components in condensed water and organic substances such as microorganisms and bacteria.

As a result, the air passing through the heat exchanger 21, as shown by the arrow B in FIG. 7, becomes deodorized and sterilized, and clean air is discharged from the air outlet in the vehicle.

As described above, according to the heat exchanger 21 having the polyaniline film 28 manufactured by the above manufacturing method, the deodorizing and antifouling function of decomposing the odor substance by the active oxygen generated when it is wet with water. Thus, it is possible to realize a heat exchanger provided with a rust preventive function for preventing rust by forming a coating film on metal.

[Brief description of drawings]

FIG. 1 is a process chart showing a method for producing a polyaniline film according to an embodiment of the present invention.

FIG. 2 is a graph showing changes in the maximum solubility of polyaniline with respect to the heating temperature of a solvent.

FIG. 3 is a graph showing the correlation of the polyaniline film coverage with respect to the polyaniline concentration for each solvent temperature.

FIG. 4 is a graph showing the amount of active oxygen generated in the polyaniline film with respect to the polyaniline concentration at each solvent temperature.

FIG. 5 is a graph showing the film thickness of a polyaniline film with respect to the polyaniline concentration at each solvent temperature.

FIG. 6 is a graph showing the weight of the polyaniline film with respect to the polyaniline concentration at each solvent temperature.

FIG. 7 is a perspective view of the vehicle heat exchanger according to the embodiment.

[Explanation of symbols]

21 ... Heat exchanger, 22 ... Piping joint, 23 ... Tube, 24 ... Heat exchange part, 25 ... Radiating fin, 26 ... Tank, 27 ... Air containing water vapor, 28 ... Polyaniline film.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hitoshi Kuno             1-1, Showa-cho, Kariya city, Aichi stock market             Inside the company DENSO (72) Inventor Osamu Kasebe             1-1, Showa-cho, Kariya city, Aichi stock market             Inside the company DENSO F-term (reference) 4D075 AB01 AB52 AB54 BB16X                       BB22X BB24Z BB92Z BB93X                       CA33 CA34 CA45 DA06 DA23                       DB07 DC13 DC16 EA07 EB44                       EB56 EC30                 4G075 AA24 AA30 AA45 BB02 BB03                       BB10 CA02 CA57 DA02 DA18                       FB02 FB20

Claims (12)

[Claims] 1. A method for producing a polyaniline film by applying a solution of polyaniline dissolved in a solvent to the surface of a member to be film-formed and drying the solution, wherein the solvent is kept at 30 ° C. to 80 ° C. By manufacturing the polyaniline film, the concentration range of the polyaniline in the solvent is set wider than that when the liquid temperature of the solvent is 20 ° C. by dissolving the polyaniline in a state of being heated within the range. Method. 2. The method for producing a polyaniline film according to claim 1, wherein the solvent is heated in a range of 40 ° C. to 60 ° C. 3. The method for producing a polyaniline film according to claim 1, wherein N-methyl-2-pyrrolidone is used as the solvent. 4. The method for producing a polyaniline film according to claim 1, wherein the coverage of the polyaniline film is controlled by controlling the concentration of the polyaniline in the solvent. Method. 5. The method for producing a polyaniline film according to claim 4, wherein the coverage of the polyaniline film is 97% or more. 6. The amount of active oxygen released from the polyaniline film is controlled by controlling the concentration of the polyaniline in the solvent.
The method for producing a polyaniline film according to any one of 1. 7. The method for producing a polyaniline film according to claim 1, wherein the film thickness of the polyaniline film is controlled by controlling the concentration of the polyaniline film in the solvent. Method. 8. The method for producing a polyaniline film according to claim 1, wherein the weight of the polyaniline film is controlled by controlling the concentration of the polyaniline film in the solvent. . 9. The film forming member is made of a material having free electrons.
9. The method for producing a polyaniline film according to any one of items 8 to 8. 10. The method for producing a polyaniline film according to claim 9, wherein the material having free electrons is a material containing aluminum as a main component. 11. A heat exchanger having a polyaniline film produced by the production method according to claim 9 or 10 in a heat exchange section. 12. The heat exchanger according to claim 11, which is mounted on an automobile.