JP4496744B2 - Plate material and manufacturing method thereof - Google Patents

Description

  The present invention relates to a plate material and a manufacturing method thereof.

  Devices such as outdoor units and indoor units of an air conditioner generally include a heat exchanger for exchanging heat with the outside air. The heat exchanger usually includes a plurality of radiating fins, a plurality of heat transfer tubes, and a blowing means such as a propeller fan. The plurality of radiating fins are plate-like members arranged at predetermined intervals in the plate thickness direction. The plurality of heat transfer tubes are mounted through the plurality of heat radiation fins in the plate thickness direction. The air blowing means is for sending an air flow to the plurality of radiating fins and heat transfer tubes.

  In this heat exchanger, the air flow is sent to the gap between the adjacent radiating fins by the air blowing means to exchange heat, and the refrigerant flowing inside the heat transfer tubes is evaporated or condensed.

  In general, a heat radiating fin is obtained by processing a plate material composed of a plate-like base material made of pure aluminum or an aluminum alloy and a coating formed on the surface of the base material into a predetermined fin shape using a mold. It is obtained by.

  As a conventional plate material, a material in which a chromate film is formed on the surface of a base material by subjecting the base material to chromic acid treatment is already known. In this plate material, the corrosion resistance is improved by the chromate film. However, since the chromate film is not sufficiently hydrophilic, if it is used as it is as the radiating fin as it is, the wettability of water is poor, and problems such as increased blowing resistance due to water droplets adhering to the surface arise.

Therefore, in order to sufficiently secure both corrosion resistance and hydrophilicity, a technique for further forming a hydrophilic film on the surface of a corrosion resistant film made of a chromate film or a water-soluble resin has already been proposed (see, for example, Patent Document 1). ). According to this technique, a plate material having sufficient corrosion resistance and hydrophilicity can be obtained. In particular, when a corrosion-resistant film made of a water-soluble resin is used, a treatment layer necessary for chromic acid treatment is not necessary, and there are further advantages in terms of production cost and environment.
Japanese Patent Laid-Open No. Sho 62-105629

  However, in the above-described conventional technology, in order to ensure adhesion of the corrosion-resistant film to the base material, a water-soluble resin containing a hydrophilic group is used, so the corrosion-resistant film may be washed away due to adhesion of water or the like. There is a problem in that the base material is corroded by the moisture that has passed through, and as a result, the durability of the plate material is lowered.

  An object of the present invention is to provide a plate material having both corrosion resistance and hydrophilic properties and improved durability.

The plate material according to claim 1 includes a plate-shaped substrate, a corrosion-resistant film, and a hydrophilic film. Corrosion-resistant film is on the surface of the substrate is formed from a corrosion-resistant coating comprising at least two-component resin as film-forming Ingredients, and a hydrophobic organic compound. The hydrophilic coating is formed from a hydrophilic coating containing a volatile organic solvent that chemically acts on the corrosion- resistant coating on the surface of the corrosion-resistant coating .

  In this plate material, since the corrosion-resistant film is made of a hydrophobic organic compound and does not have a hydrophilic group, compared to a corrosion-resistant film made of a water-soluble resin, it can be suppressed from being washed away due to adhesion of water, etc. It is possible to suppress the occurrence of corrosion of the substrate due to moisture permeation.

It is usually difficult to form a hydrophilic coating on the surface of a corrosion-resistant coating made of a hydrophobic organic compound. It has been found that a hydrophilic film can be formed on the surface by using a layer. In this plate material, two films having different properties can be formed by being overlapped by a simple method.

The plate material according to claim 2 is the plate material according to claim 1 , wherein the corrosion-resistant coating is formed on the surface of the base material not subjected to the chromic acid treatment.

  In this plate material, the corrosion-resistant film is made of a hydrophobic organic compound and has excellent durability as compared with a film made of a water-soluble resin, so that a decrease in durability due to omission of the chromate film can be suppressed. In addition, since the chromic acid treatment is not necessary for this plate material, the production cost can be reduced, and no harmful treatment waste liquid is generated.

The plate material according to claim 3 is the plate material according to claim 1 or 2 , wherein the corrosion-resistant coating is formed on the surface of the base material that has not been subjected to degreasing treatment.

  In this plate material, the pre-treatment process for the base material is reduced by omitting the degreasing process at the time of manufacture.

The plate material according to claim 4 is the plate material according to any one of claims 1 to 3 , wherein the base material is made of pure aluminum or an aluminum alloy.

  The plate-like base material made of pure aluminum or aluminum alloy is usually rolled with rolling oil when processed into a plate shape, so that the oil component remains on the surface and subjected to degreasing treatment. However, a slight amount of oil remains on the surface. However, with this plate material, the corrosion-resistant film is made of a hydrophobic organic compound, so it has better affinity with the oil component than the film made of a water-soluble resin, and it is also a good film for the substrate on which the oil component remains. Is formed.

The plate material according to claim 5 is used as a heat radiating fin of the heat exchanger in any of the plate materials according to claims 1 to 4 .

  This plate material is suitable for use in such applications because it has both corrosion resistance and hydrophilic properties by two coatings and is excellent in durability.

The manufacturing method of the plate raw material which concerns on Claim 6 is equipped with the 1st process and the 2nd process. In the first step, the corrosion resistance coating comprising at least two-component resin as film-forming Ingredients applied to the surface of the plate-like substrate to form a corrosion-resistant film comprising a hydrophobic organic compound. In the second step, a hydrophilic coating containing a volatile organic solvent that chemically acts on the corrosion- resistant coating is applied to the surface of the corrosion-resistant coating to form a hydrophilic coating.

  According to this method, since a corrosion-resistant film made of a hydrophobic organic compound is formed, it can be prevented from being washed away due to adhesion of water or the like, and moisture can be prevented from penetrating and the substrate from being corroded. .

According to this method, the hydrophilic film can be easily formed on the surface of the hydrophobic corrosion-resistant film by the organic solvent contained in the hydrophilic paint. Here, two coatings having different properties can be formed by being overlapped by a simple method.

The manufacturing method of the plate material according to claim 7 is the method of claim 6 , wherein, in the first step, the corrosion-resistant paint is applied to the base material not subjected to the chromic acid treatment.

  According to this method, since a corrosion-resistant film made of a hydrophobic organic compound is formed, even if the chromate film is omitted, the film can be satisfactorily formed on the surface of the substrate, and the chromate film is omitted. The deterioration of durability due to this can also be suppressed. Furthermore, according to this method, since no chromic acid treatment is required, the production cost can be reduced and no harmful treatment waste liquid is generated.

In the method for producing a plate material according to an eighth aspect , in the method according to the sixth or seventh aspect , in the first step, the corrosion-resistant paint is applied to a substrate that has not been subjected to the degreasing treatment.

  According to this method, the pretreatment process with respect to the base material can be reduced by omitting the degreasing treatment.

The method for producing a plate material according to claim 9 is the method according to any one of claims 6 to 8 , wherein the base material is made of pure aluminum or an aluminum alloy.

  According to this method, since a film made of a hydrophobic organic compound can be obtained, the affinity to the oil component is better than that of a film made of a water-soluble resin, and the film is well coated even on a base material on which the oil component remains. Can be formed.

The method for producing a plate material according to claim 10 is the method according to any one of claims 6 to 9 , wherein the plate material is used as a heat radiating fin of the heat exchanger.

  According to this method, since both the corrosion resistance and hydrophilic properties are provided and the durability is excellent, a plate material suitable for use in such applications can be obtained.

According to the plate material according to claim 1, the corrosion-resistant film is made of a hydrophobic organic compound and does not have a hydrophilic group. you can, also, moisture can be suppressed corrosion of passes through the substrate occurs, by a simple method, can be formed by two superposed coatings having different properties.

According to the plate raw material concerning Claim 2 , the fall of durability by having omitted the chromate film can be suppressed. Further, since chromic acid treatment is unnecessary, the production cost can be reduced, and no harmful treatment waste liquid is generated.

According to the plate material of the third aspect , the corrosion-resistant film is made of a hydrophobic organic compound and has excellent durability as compared with a film made of a water-soluble resin. . Further, according to this plate material, since chromic acid treatment is unnecessary, production cost can be reduced, and no harmful treatment waste liquid is generated.

According to the plate material of the fourth aspect, the pretreatment process for the base material is reduced by omitting the degreasing process at the time of manufacture.

The plate material according to claim 5 is suitable for use in such applications because the two coatings have both corrosion resistance and hydrophilic properties and are excellent in durability.

According to the method for producing a plate material according to claim 6 , since a corrosion-resistant film made of a hydrophobic organic compound is formed, it is prevented from being washed away due to adhesion of water or the like, and moisture penetrates and corrodes the substrate. Generation | occurrence | production can be suppressed, and two coating films from which a property differs can be formed by a simple method.

According to the method for producing a plate material according to claim 7 , since the corrosion-resistant film made of a hydrophobic organic compound is formed, the film can be satisfactorily formed on the surface of the substrate even if the chromate film is omitted. Moreover, the fall of durability by omitting a chromate film is also suppressed. Furthermore, according to this method, since no chromic acid treatment is required, the production cost can be reduced and no harmful treatment waste liquid is generated.

According to the manufacturing method of the plate raw material which concerns on Claim 8 , the pre-processing process with respect to a base material can be reduced by abbreviate | omitting a degreasing process at the time of manufacture.

According to the method for producing a plate material according to claim 9 , since a film made of a hydrophobic organic compound is obtained, the affinity for the oil component is better than that of a film made of a water-soluble resin, and the oil component remains. A film can be formed satisfactorily on the material.

According to the method for producing a plate material according to the tenth aspect , since both the corrosion resistance and the hydrophilic property are provided and the durability is excellent, a plate material suitable for use in such an application can be obtained.

[Plate material]
FIG. 1 shows a plate material 1 in which an embodiment of the present invention is adopted.

  In addition, although the plate raw material 1 preferable for using as a heat radiating fin of a heat exchanger is demonstrated here, the plate raw material 1 of this invention can be used in addition to the heat radiating fin of a heat exchanger, and it demonstrates below. The configuration is not particularly limited.

  The plate material 1 includes a base material 3, a corrosion-resistant film 5, and a hydrophilic film 7.

  The base material 3 is a plate-like member made of pure aluminum or aluminum alloy. Specifically, an Al—Cu alloy, an Al—Mg alloy, an Al—Mg alloy, an Al—Mg—Si alloy, or the like is used as the aluminum alloy. The thickness of the substrate 3 is preferably 80 μm or more, more preferably 90 μm or more, more preferably 150 μm or less, more preferably 120 μm or less, and particularly preferably 115 μm. .

  The corrosion-resistant coating 5 is formed on the surface of the substrate 3 from a corrosion-resistant paint and is made of a hydrophobic organic compound. As will be described later, the corrosion-resistant coating 5 is formed by applying a corrosion-resistant coating to the substrate 3 and drying it in the corrosion-resistant coating forming step.

  A coating made of a hydrophobic organic compound means that the coating does not have a hydrophilic group. Specifically, when the coating is analyzed using an infrared spectroscopic analyzer, a hydrophilic group such as a hydroxyl group or a carboxyl group in the infrared spectrum. It means that a peak derived from is not substantially detected.

  Specifically, the corrosion resistant paint is composed of coating film forming components, additives, solvents and pigment components. Specifically, as the coating film forming component, acrylic / melamine resins, urethane / phenolic resins, zirconium fluoride / acrylic resins are superior in corrosion resistance compared to epoxy resins used as conventional corrosion resistant coatings. A two-component resin such as a resin is preferably used. Examples of the additive include a plasticizer, a curing agent, a pigment dispersant, and an emulsifier.

  The thickness of the corrosion resistant coating 5 is preferably 0.5 μm or more, more preferably 1 μm or more, and preferably 3.0 μm or less, more preferably 1.5 μm or less. 1.0 μm is particularly preferable.

  The hydrophilic coating 7 is a coating formed on the surface of the corrosion-resistant coating 5 and is formed from a hydrophilic paint. As will be described later, the hydrophilic coating 7 is formed by applying a corrosion-resistant paint to the surface of the corrosion-resistant coating 5 and drying it in the hydrophilic coating forming step. The hydrophilic coating is composed of coating film forming components, additives, solvents, pigments, and organic solvents. Specifically, polyethylene glycol resins, polyvinyl alcohol / acrylic resins, cellulose / acrylic resins, and the like are preferably used as the coating film forming component.

  The organic solvent is not particularly limited as long as it is volatile, but ammonia, alcohol solvents and the like are preferably used. The proportion of the organic solvent to the hydrophilic paint is preferably 5% by weight or more and 20% by weight or less with respect to 100% by weight of the hydrophilic paint from the flash point and legal viewpoint.

  In FIG. 1, the interface between the corrosion-resistant coating 5 and the hydrophilic coating 7 is clearly shown for the sake of convenience. In practice, however, the organic solvent of the hydrophilic paint is chemically bonded to the surface of the corrosion-resistant coating. When the two coatings are in close contact with each other (for example, by forming irregularities on the surface), and some of the components of the corrosion-resistant coating 5 are dispersed in the hydrophilic coating 7 at the time of coating formation. Conceivable.

  The film thickness of the hydrophilic coating 7 is preferably 0.1 μm or more, more preferably 0.3 μm or more, and preferably 1.0 μm or less, and 0.5 μm or less. Is more preferable and 0.3 μm is particularly preferable.

  According to the study of the present invention, the plate material 1 configured as described above has a small contact angle in the initial state (specifically, less than 30 °). The initial state refers to a state from the time when the hydrophilic coating 7 is formed to the time including the first use.

[Plate material manufacturing method]
Next, the manufacturing method of the said plate raw material 1 is demonstrated.

  This method includes a base material preparation step, a corrosion-resistant film forming step, and a hydrophilic film forming step.

  In the base material preparation step, the base material 3 is prepared. As the base material 3 prepared here, for example, a material that is rolled using rolling oil and the rolling oil remains on the surface can be mentioned. In this step, the surface of the base material 3 may be degreased. The degreasing treatment may not be performed.

  In the corrosion-resistant film forming step, the corrosion-resistant film 5 is formed by applying the above-mentioned corrosion-resistant paint to the surface of the base material 3 without performing chromic acid treatment and drying it. As a method of applying the corrosion-resistant paint, roller coating using a roll coater or the like is preferable, but other coating methods such as spray coating, dipping, and flow coating may be used. Further, as a method for drying the corrosion-resistant paint, when application is performed by roller coating, for example, there is a method of conveying the inside of a drying furnace arranged on the downstream side of the roller for application. It is not limited to. Specifically, the drying is preferably performed for 10 minutes or less in an atmosphere having a temperature range of 180 ° C. or higher and 300 ° C. or lower. By such a drying operation, the hydrophilic group contained in the emulsifier constituting the corrosion-resistant paint disappears by changing to another functional group or the like.

  In the hydrophilic coating forming step, the hydrophilic coating 7 is formed by applying the hydrophilic paint to the surface of the corrosion-resistant coating 5 and drying it. The method of applying and drying the hydrophilic paint can be performed in the same manner as described in the corrosion-resistant film forming step, but different methods may be adopted. Specifically, the drying here is preferably performed for 10 minutes or less in an atmosphere having a temperature range of 150 ° C. or higher and 250 ° C. or lower.

  According to such a manufacturing method, since the corrosion resistant coating 5 and the hydrophilic coating 7 are formed, both corrosion resistance and hydrophilic properties can be obtained. And since the corrosion-resistant film 5 is made of a hydrophobic organic compound, compared to the corrosion-resistant film made of a water-soluble resin, there is almost no loss due to water adhesion or the like, and moisture penetrates and corrodes between the substrate 3. Is not generated or progressed. Therefore, according to this method, the plate material 1 having excellent durability can be obtained.

  Here, since the hydrophilic paint contains an organic solvent, when it is applied to the surface of the corrosion-resistant coating 5, it acts on the surface of the corrosion-resistant coating 5. The adhesion between the corrosion resistant coating 5 and the hydrophilic coating 7 increases at the interface. Therefore, according to this method, the hydrophilic film 7 can be satisfactorily formed on the surface of the corrosion-resistant film 5 by a simple method without performing a special surface treatment such as a corona discharge treatment.

  Furthermore, according to this method, since the chromic acid treatment for the base material 3 is not required, it is possible to reduce the production cost without preparing a treatment layer for the chromic acid treatment, and no processing waste liquid containing heavy metals is generated. Therefore, it is excellent in terms of environment.

  Further, the plate material 1 obtained by such a method has a corrosion-resistant coating 5 directly formed on the surface of the base material 3 without a chromate coating. The corrosion-resistant coating 5 is made of a hydrophobic organic compound. Since the corrosion resistance is excellent, it is possible to suppress a decrease in corrosion resistance due to the absence of the chromate film.

  Furthermore, since this plate material 1 has high corrosion resistance and surface hydrophilicity, as shown in FIGS. 2 and 3, heat radiating fins 11 of the heat exchanger, in particular, heat exchangers used for outdoor units. This is suitable for use as the heat radiation fin 11. The radiating fins 11 are obtained by punching the plate material 1 with a predetermined mold.

[Other Embodiments]
(A) Instead of adding an organic solvent to the hydrophilic coating, the surface of the corrosion-resistant film is subjected to a surface treatment by plasma treatment such as corona discharge, ultraviolet irradiation treatment, etc. It is also possible to apply a hydrophilic paint.

  (B) The substrate need not be made of pure aluminum or aluminum alloy.

  If the present invention is used, the corrosion-resistant film is made of a hydrophobic organic compound and does not have a hydrophilic group. Therefore, compared to a corrosion-resistant film made of a water-soluble resin, the corrosion-resistant film can be suppressed from being washed away due to adhesion of water, etc. Moreover, it is possible to suppress the occurrence of corrosion of the base material due to moisture permeation.

The longitudinal cross-sectional view which shows typically the plate raw material by one Embodiment of this invention. The top view which shows the heat radiating fin for heat exchangers which consists of the said plate raw material. The longitudinal cross-sectional view which shows the said thermal radiation fin.

DESCRIPTION OF SYMBOLS 1 Plate material 3 Base material 5 Corrosion-resistant film 7 Hydrophilic film 11 Radiation fin

Claims (10)

A plate-like substrate (3);
On the surface of the substrate (3), is formed from a corrosion-resistant paint containing resin of at least two-component as film-forming Ingredients, and a corrosion-resistant coating of hydrophobic organic compound (5),
A hydrophilic coating (7) formed from a hydrophilic paint containing a volatile organic solvent that chemically acts on the corrosion-resistant coating (5) on the surface of the corrosion-resistant coating (5) ;
Plate material (1) with The plate material (1) according to claim 1 , wherein the corrosion-resistant film (5) is formed on a surface of the base material (3) not subjected to chromic acid treatment. The plate material (1) according to claim 1 or 2 , wherein the corrosion-resistant film (5) is formed on a surface of the base material (3) that has not been subjected to a degreasing treatment. The plate material (1) according to any one of claims 1 to 3 , wherein the substrate (3) is made of pure aluminum or an aluminum alloy. The plate material (1) according to any one of claims 1 to 4 , which is used as a heat radiating fin (11) of a heat exchanger. At least two-component resin by applying a corrosion resistant coating material containing a film-forming Ingredients on the surface of the plate-like substrate (3), a first step of forming a corrosion-resistant film (5) made of a hydrophobic organic compound ,
A second step of forming a hydrophilic coating (7) by applying a hydrophilic coating containing a volatile organic solvent chemically acting on the corrosion-resistant coating (5) on the surface of the corrosion-resistant coating (5) ;
The manufacturing method of the plate raw material (1) provided with. The manufacturing method of the plate raw material (1) of Claim 6 which apply | coats the said corrosion-resistant coating material with respect to the said base material (3) to which the chromic acid process is not given at the said 1st process. The manufacturing method of the plate raw material (1) according to claim 6 or 7 , wherein in the first step, the corrosion-resistant paint is applied to the base material (3) that has not been degreased. The said base material (3) is a manufacturing method of the plate raw material (1) in any one of Claim 6 to 8 made from a pure aluminum or aluminum alloy. The said plate raw material (1) is a manufacturing method of the plate raw material (1) in any one of Claim 6 to 9 used as a radiation fin (11) of a heat exchanger.

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