JPS59118450A - Fin material made of aluminum for heat exchanger - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This 5Ff=light relates to an aluminum fin shank for a heat exchanger.

In this specification, aluminum includes aluminum and aluminum alloys.

In general, in a heat exchanger, especially an evaporator of an air conditioner, water droplets (=1) land on the surface of the fin because the temperature of the surface of the fin is below the dew point of the atmosphere.

Due to the adhesion of such water droplets, ventilation resistance increases, the air volume decreases, and heat exchange efficiency decreases. This becomes especially noticeable when the fin vidge is narrowed to improve the performance and downsize the heat exchanger. Heat exchange efficiency is greatly influenced by the wetness of water on the fin surface, and if the fin surface has a good wettability (+1-), the attached water will turn into water droplets (<), which will reduce ventilation resistance and increase the air volume. This increases heat exchange efficiency. In order to improve the wettability of the fin surface, conventional heat exchangers are formed by combining fins and dicoves, and then surface treatment is performed by immersing the heat exchanger in a solution to prevent water from getting wet on the fin surface. A method has been developed to form a hydrophilic film with good properties. However, after assembling the heat exchanger in this way, 1 (Surface treatment 4- There was a problem in that it was difficult to form a uniform film over the entire surface, resulting in variations in performance.

Therefore, the present applicants formed a hydrophilic film with good water-wetting properties on the surface of the coiled aluminum thin plate that is the material of the fin before assembling it into a heat exchanger, and then applied this film. A lubricant based on a liquid surfactant is applied to the surface of a thin aluminum plate, and the coated aluminum thin plate coated with the lubricant is pressed to form heat exchanger fins. proposed a method for manufacturing aluminum fins for heat exchangers in which lubricant is removed by washing (see Japanese Patent Application No. 112604/1982).

However, new problems arose with this method.

First, the hydrophilic film formed on the surface of the aluminum thin plate has good water wetting properties and a) f-1! It is necessary to have excellent corrosion resistance, and such a hydrophilic film is
Mainly inorganic oxide films, such as chromate films,
J, -)-(formed on a boehmite skin 111j, a citric acid film, or a combination thereof, or alternatively, a film formed by treatment in a solution containing silicic acid powder mixed in an organic substance). However, these hydrophilic films were very hard.For this reason, the fin material forming gold i (+1) was easily worn during press processing, and the life of the mold was therefore short. Since it is difficult to remove and cover all of the lubricant, a small amount of the lubricant remains on the surface of the hydrophilic film, and this lubricant attacks the hydrophilic film. There was a risk that the water-wetting properties of the film would deteriorate.Furthermore, in reality, a fin material manufacturer made a fin material made of a 1km thin aluminum plate with a hydrophilic film, and this fin material was After being sold to a heat exchanger manufacturer, heat exchanger fins are made by press processing. As a result, the hydrophilic film was contaminated and its water-wetting properties deteriorated.

The purpose of this defense is to provide an aluminum fin shank for a heat exchanger that solves the problems mentioned in section 2.

This invention will be explained below with reference to the drawings.

In FIG. 1, the aluminum fin material for heat exchangers according to the present invention has a mixture of wax and a water-soluble 11-molecule compound applied to the surface of a thin aluminum plate (1) through an intermediate layer (2) made of a hydrophilic film. The rr1 layer (3) made of a film containing the above-mentioned material is provided.

In the above, the intermediate layer (2) consisting of a hydrophilic film on the surface of the aluminum thin plate (1) has water-wet bamboo and corrosion resistance (7fV), and contains a mixture of wax and a water-soluble polymer compound. The coating layer (3) made of a film has both lubricity and hydrophilicity. Therefore, when the above-mentioned fin material is covered by press processing, due to the presence of the coating layer (3) that has lubricity on the surface, cracks do not occur in the fins, and wear of the mold is effectively prevented. Since the layer (3) itself has hydrophilic properties, the water-wetting properties of the intermediate layer (2) made of the hydrophilic film below it are not inhibited. If the coating layer (3) is removed by washing after pressing, it is possible to form a heat 52 Mokigawa Twin having a hydrophilic film (2) with good water-wetting properties on the surface.

Here, the oxide film forming the intermediate layer (2) of the fin material (Fj) is, for example, a chromate film, a veinite film,
The intermediate layer (2) is made of a silicic acid film or a combination of these films, and is obtained by treatment in a solution in which silicon 62 #) powder is moistened in an organic substance. may be configured. In order to form the intermediate layer (2) consisting of an oxide film on the surface of the aluminum thin plate (1), chemical conversion methods such as the boehmite method in deionized water, the chromate-1 treatment method, the silica sol aqueous solution treatment method, etc. Various methods are used, such as a treatment method, an anodic oxidation treatment method, or a combination of both.

The coating layer (3) of the above-mentioned twin material is made of a wax consisting of (11-) and a water-soluble polymer compound, and the socks include, for example, heptane wax, carnauba wax, oxidized polyethylene wax, microcrystalline wax, and monk wax derivatives. , sorbitol stearate, paraffin 1 noc. (14,06F, 145° [2,1
500F, 155°F), 1m micro wax, synthetic oxidized wax, castor wax, beeswax, real wax, etc. are used.

It is desirable to use such a wax with a melting point of 60° C. or higher. That's a low 81! This is because if the fin material is Knox, it will become sticky after the film is formed and the blocking resistance of the fin material will be poor. If the melting point of the wax is 60° C. or higher, the surface of the twin material will not become sticky even if it is used in summer.

In addition, water-soluble polymer compounds include methylcellulose, hydroxycellulose, carboxylcellulose polyvinyl alcohol, polyhinyl methyl ether, polyvinylpyrrolidone, polyacrylic acid, polyacrylamide, polyethylene oxide 1~, and polystyrene sulfone. Use acid, sodium alginate, etc. As such a water-soluble polymer compound, the molecule fTt20000
It is desirable to use the above 6.

Here, the mixing ratio of wax and water-soluble polymer compound is desirably 50% by weight of 011 or 10-E relative to the latter. The coating layer (3) consisting of a film containing such a mixture has both lubricity and hydrophilic properties as described above. If it is less than 50% by weight, the lubricity will be poor, and if it exceeds 50% by weight, it will become hydrophilic and water will become wet.
1 is decreasing. In addition, the mixture is applied to the surface of the aluminum thin plate (1) in the form of a dry film in an amount of bO to 200 mg/
It is desirable to apply so that m2 = 1'4ffs. Here, t12 compound E" 6th grade is 50m9/
If it is less than m2, the lubricity is insufficient, and if it exceeds 200 mg 7m2, molding defects are likely to occur during press working.

The mixture is applied in the form of an aqueous solution, and the amount of water may be adjusted as appropriate so that the amount of the mixture falls within the above range. For example, the moisture content of the aqueous mixture solution is adjusted to about 10%.

In addition, a small amount of nonionic surfactant is added to the mixture of wax and water-soluble polymer compound in order to mix them evenly, and a small amount of metal soap is added to further improve the lubricity. It is preferable to do so. here,
As the non-ionic surfactant, for example, polyoxyethylene ether and Nisdel are used. As the metal soap, for example, sodium salts, lithium salts, aluminum salts, calcium salts, magnesium salts, barium salts, etc. of higher fatty acids are used.

An aqueous solution containing wax, a water-soluble polymer compound, and in some cases a small amount of surfactant is poured onto a thin aluminum plate (1
) on the surface of the intermediate layer (2), for example 10
By drying at 0-150°C, a coating layer 3) consisting of a film containing a mixture of wax and a water-soluble polymer compound is formed on the main binding.

The press processing for forming the aluminum fin material heat exchanger fins according to the present invention includes, for example, stretching processing, drawing processing, punching processing, curling processing, and pressing the cylindrical rising wall around the J5 and tube insertion holes to cover them high. Includes [shigokika] - etc. In addition, when the aluminum twin mill is in the form of a coil, this process also includes a cutting surface process in which the fin material is VJ-cut to a predetermined length, which is performed subsequent to these processes. Since the aluminum fin material is provided with a coating layer (3) consisting of a film containing a mixture of wax and water-soluble polymer compound as described above, pressing can be performed extremely smoothly, and heat Exchanger fins can be made efficiently and there is less wear on the mold. Furthermore, the a-covering layer (3) does not inhibit the water-wetting properties of the intermediate layer (2), which is a hydrophilic film previously formed on the fin surface.

After press processing? The heat exchanger fin having the 112m layer (3) is cleaned with perchloroethyl alcohol and the like to remove the coating layer <3). As a result, a fin having an intermediate layer (2) made of a hydrophilic film with good water-wetting properties on the surface is obtained. Note that a coating layer (
Even if some of 3) remains, there is no problem at all since this does not inhibit the water-wetting properties of the film.

Although the fin material according to the present invention may be press-processed as it is, as shown in FIG.
You can also apply liquid lubricant (4) on the surface of 3) and press it. It can be molded.

Here, the lubricant (4) is the one described in the earlier application of the previous application, which has a surfactant as a base material that is liquid at room temperature, and in which a phosphorus-based extreme pressure additive is added as a base material. , higher fatty acids,
A lubricant containing at least one substance of a higher fatty acid ester and a higher alcohol may be used,
Alternatively, a mineral oil-based lubricant that is generally used in press working may be used.

The liquid surfactant used as the basis of lubricant (4) for J3 pre-cooking has good lubrication performance, is easy to clean, and has a wetting property itself.

The phosphorus-based extreme pressure additive, higher fatty acid, higher fatty acid ester, and higher alcohol added to this base material are all added to improve the lubricating properties of the lubricant, that is, the press working properties.

Here, examples of the surfactant that are liquid at room temperature include polyoxyethylene nonylphenyl ether, Δcutylphenyl ether, primary or secondary higher alcohol ethylene oxide adduct, fatty acid polyethylene glycol ester, solhitan monooleyl ester, Polyethylene glycol, secondary alcohol having 12 to 14 carbon atoms, dylene oxide (=J) + proboscis, etc. are used.

As a phosphorus-based extreme pressure additive, for example, a carbon number of 10 to 18
A dialkyl hydride having 1-cozenephosphite 1- and a trialkyl small sphite are used.

As the higher fatty acid, for example, one having 10 to 20 carbon atoms is used, and specifically, lauric acid, palmitic acid, A-leic acid, tallow fatty acid, alkenylsuccinic anhydride, and sudeariic acid are used.

Higher fatty acid esters include the above fatty acids and carbon atoms of 1 to 1.
An ester with 18 alcohols is used.

The higher alcohol has, for example, a carbon number of 12 to 18, and specifically includes lauryl alcohol, oleic alcohol, allyl alcohol, isostearyl alcohol, oxo alcohol, and the like.

The lubricant (4) has a surfactant as a base material, and contains a substance such as the above-mentioned phosphoric acid-based extreme pressure additive in a proportion of 0.1 to 20% by weight, preferably 3 to 5% by weight. ing.

During press working, apply lubricant (4) as above.
However, since the surface of the fin material according to the present invention is provided with a coating layer (3) consisting of a film containing a mixture of wax and a water-soluble polymer compound, the lubricant (4) is applied to the aluminum thin plate. There is no direct contact with the intermediate layer (2) made of a hydrophilic film on the surface of (1). Therefore, even if a general mineral oil-based lubricant is used as the lubricant 4), the water wettability of the intermediate layer (2) consisting of a hydrophilic film will not be impaired, and liquid surfactant Even if a base lubricant is used, this lubricant can be completely and very easily removed during subsequent cleaning, and the intermediate layer (
There is no deterioration in the water-wetting property of 2).

For press processing corrosion, the lubricant (4) and the coating layer (3) are removed at the same time by cleaning. Also, what about the surface of the fins after cleaning? Even if a part of the EL coating layer (3) remains, there is no problem because this does not inhibit the water-wetting properties of the hydrophilic film.

As described above, the aluminum foil for heat exchangers according to the present invention has a mixture of wax and water-soluble polymer compound applied to the surface of the thin aluminum plate (1) through the intermediate layer (2) made of a hydrophilic film. Since the coating layer (3) has both lubricity and hydrophilicity, this fin material can be pressed as is. As a result, it is possible to manufacture heat exchanger fins with low efficiency, and the wear of the mold is effectively prevented, increasing the life of the mold. has hydrophilicity and therefore the water wettability of the intermediate layer (2) consisting of the hydrophilic film on the T side is not occupied by the concave 1'. ’!By removing layer (3), a hydrophilic film (2) with good water-wetting properties is formed on the surface.
) can form a heat exchanger two-in.

A3: Even if a part of the coating layer (3) remains after washing, the water-wetting properties of the hydrophilic film (2) will not be affected. Since the skin layer (3) is provided on the surface of the fin material, even if the fin material is left for a long time, the middle layer (2) consisting of hydrophilic components will not absorb air. Since the middle layer (2) is not exposed at all, the water-wetting properties of the middle layer (2) do not deteriorate.

In addition, lubricant ('1.
) is applied after press working, the thermal lubricity is even better, the moldability is improved, and wear of the mold can be further prevented. Moreover, since the coating layer (3) exists between the lubricant (4) and the intermediate layer (2) made of a hydrophilic film, the lubricant (4) comes into direct contact with the intermediate layer (2). Therefore, the use of the lubricant (4) will not deteriorate the water wettability of the intermediate layer (2).

And by washing after press processing, dvj lubricant (/I)
The coating layer (3) and the coating layer (3) can be easily removed, and even if some coating layer (3) remains, the coating layer (3) itself has hydrophilic properties (water on the fin surface It has the advantage that the wettability does not deteriorate.

Next, this invention will be explained in detail.

EXAMPLE An aluminum twin 1 for a heat exchanger according to the present invention was manufactured as follows.

；Lzu19mi0. 115mm aluminum (△11
After degreasing the T1 tile material (1) manufactured by 00-1-12/l'), oxidized 1 com (Crz
o3) Perform chromate treatment by spraying an aqueous solution containing 5% silica for 15 seconds at 60°C, and then coat this coil material (1) with 1.8% silica
Coil ′+A
(On the surface of 2), the mate film and silicate film are 2
Intermediate layer (2) consisting of a hydrophilic film divided into stages
was formed. When the contact angle of the original coil material (1) due to water wetting was measured, it was 60', and the contact angle of the coil material (1) after degreasing was 45°.

Next, on the surface of the coil material (1) having the intermediate layer (2) made of a hydrophilic film, an aqueous solution containing a mixture of various waxes and water-soluble polymer compounds is continuously applied as shown in the table below. After that, this is dried at 110 to 150°C to form a coating layer (3) on the surface of the coil material 1) with a coating containing a mixture of wax and a water-soluble tlJ polymer compound via an intermediate layer (2). A fin material for a heat exchanger was manufactured. Here, the coating layer (3) (=J hanging is 120II1g
/m2.

Next, by pressing the fin material according to the present invention as it is, a cold tube insertion hole is formed, and an upright cylindrical portion having a bent tip (flare) is formed at the periphery of this insertion hole. A heat exchanger fin was manufactured by making a rectangular fin of a predetermined size and washing the fin with perchlorethylene (and removing the surface coating layer (3)).

Evaluation Test In order to evaluate the lubricity of the coating layer (3) on the surface of the fin material according to the present invention manufactured according to the above example, the wear of the mold after molding the above fin material for 1000 m and the flare of the fin were conducted. The degree of cracking (formability) was measured and the obtained results are summarized in the table below.For comparison, an aluminum coil material (2) with an intermediate layer (2) made of a hydrophilic film (
1) Apply a conventional mineral oil lubricant to the surface of the
Pressing was carried out in the same manner as above, and the obtained results are also shown in the table. Further, after the press working, the contact angle due to water wetting of the heat exchanger fins was measured immediately after the coating layer (3) was removed by washing, and the obtained results are shown in the table below.

Mold wear O: No mold wear was detected.

×: The mold's f-shank stands up.

In the table above, when comparing the fin material according to the present invention and the fin material according to the comparative example, it is clear that the fin material according to the present invention does not crack during press working, and the PL of the mold
There is very little wear and tear. Furthermore, the heat exchanger fins after press working have a very small surface contact angle and therefore have excellent water wetting properties, but the water wetting properties at the mouth do not deteriorate over a long period of time.

In addition, the surface of the fin material of the above example was coated with a liquid surfactant as a base material, and at least one substance selected from phosphorus-based extreme pressure additives, commercial fatty acids, higher fatty acid esters, and higher alcohols. When a lubricant (4) containing 0.1 to 20% by weight and a general mineral H1+-based lubricant (4) were applied and pressed, the molding of heat exchanger fins was made even smoother. [Ic 0 pressing] After that, the fins do not crack, and the wear of the mold is even less.] After washing, a film containing a mixture of wax and a water-soluble polymer compound is formed. Covering layer (3)
When both the lubricant and lubricant (4) were removed and the contact angle on the fin surface was measured, the same results as in the table above were obtained, indicating that the water wettability of the fin surface was good.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of an aluminum fin material for a heat exchanger according to the present invention, and FIG. 2 is an enlarged sectional view of the fin material shown in FIG. 1 with lubricant applied to the surface. (1) ... Aluminum thin plate, (2) ... Intermediate layer,
(3)...Coating layer, (4)...Lubricant. Applicant for the above patents: Daido Chemical Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] An aluminum for heat exchanger, in which a coating layer (3) made of a film containing a mixture of wax and a water-soluble polymer compound is provided on the surface of a thin aluminum plate (1) via an intermediate layer (2) made of a hydrophilic film. Made with fins.