JPH03247782A - Surface treatment for aluminum member - Google Patents

Abstract

PURPOSE:To carry out surface treatment for an Al member in which the control of surface color tone is facilitated by bringing an aqueous solution of metal chloride in which dye or pigment is dissolved or dispersed into contact with the surface of an Al member preheated to a temp. in the prescribed range and simultaneously applying etching treatment and coloring treatment to the above surface. CONSTITUTION:An Al member is preheated to 50-120 deg.C, and an aqueous solution of metal chloride in which dye or pigment is dissolved is brought into contact with the surface of the above Al member. As this metal chloride, iron (II) chloride, iron (III) chloride, copper (I) chloride, copper (II) chloride, etc., are preferred. By the above contact treatment, the surface of the Al member is etched by Cl<-> in the aqueous solution of metal chloride and an etched film is formed at high formation velocity. Simultaneously, the dye or pigment dissolved in the above aqueous solution is sealed in the above etched film, by which the dye or pigment is fixed in a stable state on the surface of the Al member and the whole surface can be colored. The above treatment is a surface treatment for Al member which is effective in application for producing, in particular, an Al overhead power transmission wire and its accessories having a color tone harmonized with line environment.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a surface treatment method for aluminum members, and more specifically, for example, for aluminum overhead power transmission lines and accessories such as jumper devices used in the overhead line, the present invention relates to a method for surface treatment of aluminum members. The present invention relates to a surface treatment method for aluminum members that can be made dark in color to harmonize with the overhead line environment.

(Prior Art) Generally, the surface of an aluminum member is silvery white and has a very high reflectance to light. Among these aluminum members, for example, aluminum overhead power transmission lines and spiral rods and jumper devices used when connecting them have traditionally been roughened by sandblasting on the surface in order to harmonize with the overhead line environment. In addition to chemical treatment and boehmite treatment, the surface is coated with paint or anodized.

By applying such surface treatment, the light reflectance on the surface of aluminum overhead power transmission lines and their accessories is reduced, achieving a certain degree of harmony with the environment, and the treated surface becomes hydrophilic, preventing water droplets from forming. O-diple noise due to corona discharge caused by adhesion is reduced.

(Problem to be Solved by the Invention) However, in the case of the above-mentioned sandblasting treatment and boehmite treatment, the color tone of the treated surface of the obtained aluminum power transmission line and its accessories is light color, and the color tone is darkened or Difficult to darken. Therefore, the surface color tone cannot be harmonized with the overhead wire environment.

In addition, in the case of painting, the color tone of the formed surface coating film cannot be maintained for a long period of time, and furthermore, the hydrophilicity is impeded and the above-mentioned audible noise is increased (which is unavoidable). Furthermore, in the case of anodic oxidation treatment, the power consumption during treatment is large, which increases the overall treatment cost including equipment cost.

The present invention solves the above-mentioned problems in conventional surface treatment methods, the surface color is easy to adjust, and the color is dark and stable, and hydrophilic, especially harmonious with the overhead line environment. The object of the present invention is to provide a surface treatment method for aluminum members that is effective when applied to the production of aluminum overhead power transmission lines with color tone and their accessories.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a step of preheating an aluminum member at a temperature of 50°C or more and less than 120°C, and a step of preheating the aluminum member on the surface of the preheated aluminum member. Surface treatment of an aluminum member, characterized in that it comprises the steps of: simultaneously applying an etching treatment and a coloring treatment to the surface of the aluminum member by contacting it with an aqueous metal chloride solution in which a dye or pigment is dissolved or dispersed. A method is provided.

In the present invention, in the latter step described above, the surface of the aluminum member is etched with chlorine ions in the metal chloride aqueous solution to form a corrosion film at a high rate, and at the same time, it is dissolved in the metal chloride aqueous solution. The dyes or pigments are encapsulated in this corrosion film, and the dyes or pigments are stably fixed on the surface of the aluminum member after treatment, and the entire surface is colored.

First, the first preheating step is performed at a temperature of 50° C. or higher and lower than 1208° C.

If this preheating temperature is less than 50°C, when the metal chloride aqueous solution comes into contact with the surface of the aluminum member in the next step, the above-mentioned etching effect will not be fully exerted.
This is because the corrosion film is insufficiently formed and the dye or pigment is not sufficiently contained (immobilized) therein, and the color will fade if it comes into contact with rainwater for a long period of time. In addition, when the preheating temperature is less than 50°C, the metal chloride aqueous solution that comes into contact with the surface of the aluminum member does not finish evaporating in a short time (within a few minutes), and as a result, it is difficult to form a highly hydrophilic surface. This is because.

If the preheating temperature is 120° C. or higher, the formation of a corrosion film due to etching and the immobilization of the dye or pigment associated with it will reach saturation, resulting in wasted thermal energy. Preferable preheating temperature is 70-100°C
It is.

In the next step, the surface of the preheated aluminum member is brought into contact with an aqueous metal chloride solution to be described later. As a mode of this contact, a method of spraying an aqueous metal chloride solution onto the surface of the aluminum member is suitable.

The metal chloride aqueous solution used is prepared by dissolving the metal chloride and the dye or pigment.

Any metal chloride may be used as long as it dissolves in water and dissociates chlorine ions; for example, iron chloride (■
), iron chloride (■), copper chloride (■).

Preferred examples include one or more of copper chloride (■), cobalt chloride, chromium chloride (n), barium chloride, and nickel chloride. Among these, iron chloride (■
), iron chloride (■), copper (I) chloride.

Copper (II) chloride is particularly suitable since it has an excellent etching effect on the surface of aluminum members.

These metal chlorides have a chloride ion concentration of 50 to 40
It is preferable to dissolve it so that it becomes 0 ppm. If the chlorine ion concentration is less than 50 ppm, the etching effect on the aluminum member surface will be small regardless of the preheating temperature in the preheating process, and
This is because the etching effect reaches saturation even if the concentration is higher than pm. A particularly preferred chloride ion concentration is 100 to 300 ppm.

Examples of dyes that can be dissolved in this metal chloride aqueous solution include ALIZARINE FASTBLUE.
Acidic dye such as R (trade name, manufactured by CIBA); AL
Acidic mordant dyes such as FAST BROWN SW#5402 (trade name, manufactured by Orient Chemical Co., Ltd.) are suitable;
If the oil-soluble dye is soluble in the above-mentioned alcohol, it can be used sufficiently by dissolving the oil-soluble dye in the minimum required amount of the above-mentioned alcohol and then blending the alcohol solution with the metal chloride aqueous solution.

In addition, as a pigment, for example, VYNAMONBLUEG
Phthalocyanine pigments such as VIOLET TONER (trade name, manufactured by ICI Corporation), benzidine pigments such as VIOLET TONER (trade name, manufactured by Tokyo Shikizai ■) can be used, and carbon black can be added to a trace amount of nonionic surfactant. The amount of these dyes or pigments to be dissolved or dispersed is determined by the desired color tone, its lightness and saturation, and it is determined by the dye used. Although it cannot be determined unambiguously because it varies depending on the hue, chemical structure, etc. of the pigment, an amount of 0.4% by weight or less is sufficient regardless of the type of dye or pigment.

Note that it is effective to roughen the surface of the aluminum member by performing sandblasting as in the conventional method prior to the preheating step, as this further reduces the light reflectance of the surface.

(Embodiments of the invention) Example 1゜The aluminum member is an aluminum overhead power transmission line, and the first
The colored aluminum overhead power transmission line of the present invention was manufactured using the manufacturing line illustrated in the figure.

First, in this production line, between the supply 1, in which the aluminum overhead power transmission line to be subjected to surface treatment (Munsell display brightness 7.2) is wound, and the coiler 2, which winds the treated aluminum overhead power transmission line, , a high frequency induction heating furnace 3, a bathtub 4, and a caterpillar feeding device 5 are arranged in this order.

An aluminum overhead power transmission line 6 was let out from the supply 1 at a running speed of 2 m/min, passed through a high frequency induction heating furnace 3, and its surface temperature was controlled at 90±5°C.

Next, the metal chloride aqueous solution 4a stored in the bathtub 4 was siphon-sprayed onto the surface of the aluminum overhead power transmission line 6 from three sets of atomizing nozzles 8 using compressed air 7.

The metal chloride aqueous solution 4a used was iron(II) chloride 0.2
weight% (chloride ion concentration: 260 ppm) and acidic mordant dye (Orient Chemical (shared product; ALFAS)
T BLACK SW#5803) 0.07% by weight
It is an aqueous solution containing.

The amount of spray at this time was adjusted to such an extent that the surface of the aluminum overhead power transmission line was not completely wetted, but the spray liquid was attached at discontinuous points, so that water evaporation was completed within 10 seconds. did.

The surface of the aluminum overhead power transmission line that passed through the caterpillar device 5 and was wound around the coiler 2 was colored a dark brown (Munsell brightness 3.3). This aluminum overhead power transmission line was exposed outdoors for 10, 70, and 180 days, and the fading state and the wettability and spreadability of rain water droplets during that time were investigated.The surface remained unchanged from immediately after being colored, and the wettability and spreadability was also extremely good. there were.

Example 2 High frequency induction heating furnace 3 in the production line shown in Fig. 1
The surface temperature of the aluminum overhead power transmission line 6 was controlled at 56 ± 4°C by changing it to a pipe furnace with heating wire wrapped around it. The aqueous solution contained 160 ppm), 0.03% by weight of phthalocyanine blue, and 0.03% by weight of benzidine orange, and the spray amount was 25% by weight.
An aluminum overhead power transmission line was surface treated in the same manner as in Example 1, except that the amount of water was such that it would evaporate in ~40 seconds. The surface was colored gray with a dark blue color (Munsell brightness 5.7).

Under the same conditions as in Example 1, the fading state and the wettability of rain water droplets were examined. No fading was observed regardless of the number of days of outdoor exposure. Slightly insufficient wettability was observed after 10 days of outdoor exposure, but after 70 days and 180 days of outdoor exposure,
It was extremely good on days.

Example 3 The running speed of the aluminum overhead power transmission line was 3 m/min, the preheating temperature was controlled at 110 ± 6°C, and the metal salt aqueous solution contained 0.04% by weight of iron (I) chloride (chloride ion concentration). 70ppm) and azo oil-soluble dye (Odugaya Chemical Co., Ltd.)
Product made by: AIZENSPILON 0RANGE
The surface treatment was carried out in the same manner as in Example 1, except that the sample contained 3% by weight of a 4% by weight methanol solution of 2RH). The surface is dark (Munsell brightness: 4.
5) was colored.

In the same manner as in Example 1, changes in the fading state and the wettability of rainwater droplets were investigated. No fading was observed, and the wetting and spreading properties were good.

Example 4 The surface of an aluminum jumper device part, which is an accessory for an aluminum overhead power transmission line, was roughened by sandblasting, and then heated in an air furnace at a temperature of 90±3°C for 40°C.
After heating it for a minute, and taking it out of the furnace, at the same time, 0.1% by weight of iron(II chloride) (chloride ion concentration 13%) was added to the surface.
0ppm) and acid dye (Sumitomo Chemical Co., Ltd. product LAN
An aqueous solution containing 0.03% by weight of YL BLUE3G) was sprayed with a paint sprayer. Water evaporation was completed in 15 to 20 seconds. The surface was colored dark bluish brown (Munsell brightness 4.4).

No fading was observed even under the same outdoor exposure conditions as in Example 1, and the wettability and spreadability of rainwater droplets was also extremely good.

(Effect of the invention) As is clear from the above explanation, according to the method of the present invention,
It is possible to darken the color tone of the surface of aluminum members and reduce the light reflectance on the surface, and when applied to aluminum overhead power transmission lines and their accessories, it is possible to create a surface condition that allows them to easily harmonize with the overhead line environment. can. Moreover, the formed color tone is maintained over a long period of time and has good hydrophilicity, so in the case of aluminum overhead power transmission lines, UHV
This is caused by rainwater droplets that adhere during power transmission.
Audible noise based on corona discharge is reduced by 4 degrees.

In addition, this method is an extremely simple surface coloring method for aluminum parts because it simply involves spraying the metal chloride aqueous solution on the aluminum parts. It is useful to be able to manufacture aluminum overhead power transmission lines and their accessories in the overhead line environment with high productivity and low cost.

[Brief explanation of drawings]

FIG. 1 is an example of a production line used when producing colored aluminum overhead power transmission lines by the method of the present invention. ■... Supply, 2... Coiler, 3... High frequency induction heating furnace, 4... Bathtub, 4a... Metal chloride aqueous solution, 5... Caterpillar device, 6... Aluminum overhead feed Electric wire, 7... Compressed air, 8... Atomizing nozzle.

Claims (1)

[Claims] Preheating the aluminum member at a temperature of 50°C or higher and lower than 120°C; and contacting the surface of the preheated aluminum member with an aqueous metal chloride solution containing a dye or pigment dissolved or dispersed therein to heat the aluminum member. A method for surface treatment of an aluminum member, comprising the steps of simultaneously applying etching treatment and coloring treatment to the surface.