JP3192950B2 - Method of forming anticorrosion film of copper or copper alloy material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for a copper or copper alloy material such as a plate, a wire, a pipe and the like. Provided is a method for forming a rust-preventive film of copper or a copper alloy material capable of uniformly forming a strong rust-preventive film in a subsequent rust-preventive film forming step.

[0002]

2. Description of the Related Art In general, benzotriazole (BTA) or a derivative thereof is used as a rust inhibitor for copper or copper alloy materials. Hereinafter, BTA and its derivatives are collectively referred to simply as BTA. The rust prevention effect of BTA is due to the formation of a BTA polymer film on the surface of copper or a copper alloy material. That is, a thin copper oxide film on the order of atoms is naturally formed on the surface of the copper or copper alloy material, but the BTA molecules form strong coordination bonds with the copper oxide, and the BTA molecules form Also form a covalent bond,
A strong BTA polymer film is formed on the surface of the copper or copper alloy material. The BTA polymer film thus formed has excellent adhesion to copper or a copper alloy material, and also has extremely excellent corrosion resistance. The surface of the copper or copper alloy material is corroded and discolored due to the corrosion. Protect.

FIG. 2 is a block diagram showing a conventional rust-proofing method using this BTA. First, copper or a copper alloy material processed into a shape such as a plate, a wire, or a pipe is degreased by pickling (step 1), washed with water (step 2), and then dried once (step 3). The pickling in Step 1 is performed using sulfuric acid, nitric acid, phosphoric acid, chromic acid, or the like for the purpose of removing oxides or processing lubricating oil. Further, the drying in Step 3 has an effect that the BTA easily reacts with the processing material because a thin copper oxide layer is formed on the surface of the processing material by this drying process. Then, the treatment material is changed to B
It is immersed in a solution containing TA, or this solution is applied to a treatment material and BTA-treated (step 4), and finally dried (step 5) to obtain a product. In the BTA treatment in Step 4, a solution in which BTA is dissolved in a solvent such as water, alcohol, or trichloroethane is used. The rust-preventive solution is preferably at 50 to 80 ° C.

In the steps 1 to 5, if the rust-preventive film is not coated on the surface of the processing material to a sufficient thickness, the rinsing in step 2, the drying in step 3 and the BTA processing in step 4 are performed again. And a drying process of step 5 to form a rust prevention film having a sufficient thickness. Step 5
Is dried to make the formed BTA polymer layer stronger. This drying process can use hot air of 150 ° C. or less.

In general, the series of steps 2 to 5 shown in FIG. 2 is usually completed only once, but it is actually preferable to repeat it twice or more.
In that case, after the end of step 5, perform weak pickling,
Steps 2 to 5 may be performed after the pickling. Steps 2 to 5 are repeated twice or more because a complete BTA rust-preventive film may not be formed in a single process, and the defective portion is completely protected from BTA by the second and subsequent processes. This is because an attempt is made to form a rust film.

[0006]

However, in such a rust-preventing treatment method, even if steps 2 to 5 are repeated a plurality of times, the BTA protective film is not completely formed, and a defective portion remains. There is a point. And
Corrosion or discoloration occurs from the defective portion. Further, by repeating the processing steps a plurality of times, a time loss occurs.

Therefore, the inventors of the present invention have proposed that the processing material be BTA
In order to form a uniform rust preventive film on the surface of the processing material instead of immersing it in a solution containing or applying this solution to the processing material, a technique was proposed in which BTA was sprayed onto the processing material by a jet stream. (Japanese Patent Application No. 7-197299). By such processing, the BTA processing speed shown in step 4 of FIG. 2 is reduced. However, in this method, the time required for the pretreatment for forming the rust-preventive film shown in Steps 2 and 3 is not reduced. In addition, it is difficult to sufficiently remove the acid and oil remaining on the surface of the processing material only by washing with water in step 2 and drying in step 3, and a copper oxide layer may not be formed uniformly.

The present invention has been made in view of the above problems, and it is possible to sufficiently remove acid and oil on the surface in a short time, and to provide a strong rust prevention film in a subsequent rust prevention film forming step. An object of the present invention is to provide a method for forming a rust-preventive film of copper or a copper alloy material, which can form a rust film uniformly.

[0009]

According to the method for forming a rust-preventive film of copper or a copper alloy material according to the present invention, the ejection pressure is 10 to 200 k.
gf / cm ² , hot water of 60 ° C. or more is sprayed onto the drawn copper or copper alloy material by a jet jet to the surface thereof.
After forming the copper oxide layer , the copper or copper alloy material is treated with a solution containing benzotriazole or a derivative thereof.

[0010]

The BTA rust preventive film has a property that it is easily formed on a thin copper oxide layer. Therefore, the inventors of the present application have found that a thin copper oxide film can be uniformly formed on the surface of the processing material by spraying hot water of 60 ° C. or higher on the processing material with a high-pressure jet jet instead of hot-air drying. . By this pretreatment with hot water, a strong rust prevention film can be uniformly formed in the subsequent BTA treatment. Therefore, the steps of washing and drying, which have been conventionally performed as a pretreatment for forming a rust-preventive film, can be shortened.

If the temperature of the hot water is lower than 60 ° C., the copper oxide layer may not be formed sufficiently on the surface of the treated material, or an uneven copper oxide layer may be formed. Therefore, in the present invention, the temperature of the hot water is set to 60 ° C. or higher. The upper limit of the hot water temperature is not particularly specified, but the water temperature is 1 at normal pressure.
When the temperature rises to around 00 ° C., the hot water used boils. Therefore, in order to enable processing at a high temperature exceeding 100 ° C., it is necessary to take measures such as adapting the entire processing system to high pressure.

Further, ejection pressures of the jet stream is shall be the 10 to 200 kgf / cm ^2. This means that the jet pressure is 10
If it is less than kgf / cm ² , the effect of the jet jet will not be exhibited, and only an effect equivalent to that of the water washing that has been usually performed can be obtained. On the other hand, when the ejection pressure is 200
If the pressure exceeds kgf / cm ² , erosion in which the surface of the treatment material is mechanically damaged by water pressure is likely to occur.
If the pressure is 10 to 200 kgf / cm ² ,
Since this is generally commercially available as a plunger pump capable of ejecting liquid within this pressure range, this step can be easily performed.

As described above, according to the present invention, it is possible to sufficiently remove surface acids and oils in a short time as compared with the conventional pretreatment method by washing and drying, and
A thin copper oxide layer on which a rust prevention film is easily formed can be formed uniformly. Therefore, in the subsequent BTA treatment, a strong BTA rust prevention film is uniformly formed on the copper or copper alloy material,
Corrosion and discoloration can be reliably prevented.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the accompanying drawings. FIG. 1 is a schematic sectional view showing a method for forming a rust-preventive film of copper or a copper alloy material according to an embodiment of the present invention. A case where a wire is used as an example of the processing material will be described.

First, as a pre-treatment for forming a BTA anti-rust film,
The wire 14 is passed through the pretreatment container 13 shown in FIG. This wire rod 14 is processed to a desired diameter by being passed through a wire drawing die, but immediately after the wire drawing step is performed, the surface of the wire rod 14 is hardly oxidized. The pickling process of Step 1 in Step 2 can be omitted. On the other hand, when this pretreatment is not immediately after the wire drawing step, the wire 14 is pickled, then washed with primary water by a conventional method, and introduced into the pretreatment vessel 13. Temporary water washing after pickling is effective to obtain a higher pretreatment effect.

The pretreatment container 13 used in this embodiment
Has a box shape with a capacity of about 100 cc, for example, a hot water inlet 11 of 60 ° C. or higher is formed on an upper wall, and a discharge port 12 is formed on a lower wall. A hole through which the wire 14 passes is formed on both side walls of the pretreatment container 13, and a distance between the side walls is, for example, 0.1 m. Therefore, while the wire 14 passes through the inside of the pretreatment container 13 in the direction of the arrow, a portion of 0.1 m is pretreated in the pretreatment container 13. The wire 14 is driven to move in the direction of the arrow by a feeding or winding device (not shown) disposed on the upstream side or the downstream side, respectively. After that, the wire 14 is subjected to a BTA processing step of forming a rustproof film.

In the method of the present embodiment using the pretreatment container having the above-mentioned structure, the wire rod 14 is moved in the direction of the arrow and the injection port 11 is, for example, 50 kgf / cm ^2. Hot water at 80 ° C. is injected into the pretreatment vessel 13 by a high-pressure jet jet. Then, the jet jet collides with the surface of the wire 14 to remove deposits such as acid and oil on the surface, and a thin copper oxide layer is uniformly formed on the surface of the wire. This copper oxide layer is assumed to be Cu ₂ O. At this time, the moving speed of the wire rod 14 is 600 m / min, that is, 1
If it is set to 0 m / sec, the pretreatment time for the treatment length of 0.1 m of the wire 14 is 0.01 second, and the effect of removing acid and oil is extremely high despite the short pretreatment time.

Next, in order to verify the effect of the present invention, the wire obtained by the method of this embodiment and the wire obtained by conventional washing with water and hot-air drying are subjected to BTA treatment and dried. Was. Thereafter, a sodium sulfide test was performed on each wire. This sodium sulfide test is generally performed as a method for evaluating the rust-preventive effect of copper or a copper alloy material. The degree of discoloration is evaluated. The evaluation results are shown in Table 1 below. However, the wire used was a tough pitch copper wire having a diameter of 1.0 mm, and the condition of hot air drying was 30 seconds in a static state. In the BTA treatment, the wire was immersed in a 0.1% aqueous BTA solution at room temperature for one minute. In the column of the evaluation results of the rust prevention effect, は indicates that the surface of the test material did not change color at all, △ indicates that the color changed slightly, and X indicates that the color changed significantly.

[0019]

[Table 1]

As shown in Table 1, with respect to Comparative Example 2, the discoloration of the surface of the test material progressed with the passage of time, indicating that a complete rust prevention film was not formed. On the other hand, in Example 1 of the present invention, discoloration of the surface of the test material was not observed even after 5 minutes of immersion in the aqueous sodium sulfide solution, and extremely excellent protection was obtained in the same BTA treatment as the comparative example. Demonstrated the rust effect.

Further, the degree of coating of the rust-preventive protective film was evaluated on the wire pretreated at the hot water temperature shown in Table 2 below under the same conditions as in the sodium sulfide test shown in Table 1 above. The jet pressure of the jet at this time is 50 kgf / cm ² Unified. These evaluation results are shown in Table 2 below.

[0022]

[Table 2]

As shown in Table 2 above, the hot water temperature was 60 ° C.
In Examples 11 to 13 described above, the adhesion state of the BTA rust-preventive film was excellent, so that discoloration was prevented in the immersion test of the aqueous sodium sulfide solution. In contrast, Comparative Example 14 using unheated water and Comparative Example No. using warm water at 50 ° C. As for No. 15, only the same degree of coverage as that of the wire rod which had been subjected to the pretreatment by the conventional water washing and hot air drying could be obtained.

Next, the same sodium sulfide test was carried out on the wire rod which had been subjected to the pretreatment with the ejection pressure shown in Table 3 below. The hot water temperature at this time was 80 ° C. The results of these evaluations are shown in Table 3 below.

[0025]

[Table 3]

As shown in Table 3, in Examples 21 to 24 in which the jet pressure of the jet stream is 10 to 200 kgf / cm ² , the occurrence of discoloration is prevented by the immersion test of the aqueous sodium sulfide solution. On the other hand, in Comparative Example 25 in which the jet pressure of the jet stream was low, discoloration was likely to occur. On the other hand, in Comparative Example 26 in which the ejection pressure was high, although discoloration due to corrosion did not occur, the surface was roughened significantly by erosion.

In this embodiment shown in Tables 1 to 3, copper or a copper alloy wire is used. However, similar effects can be obtained with plates or pipes other than the wire.

[0028]

As described above in detail, according to the method of the present invention, hot water of 60 ° C. or more is sprayed on a copper or copper alloy material by a high-pressure jet jet to perform a pretreatment for forming a rust preventive film by BTA. Therefore, the acid and oil on the surface of the copper or copper alloy material can be sufficiently removed in a short time, and the
A uniform copper oxide layer is formed on the surface . Further, at the time of the BTA treatment after the pretreatment, a strong rust prevention film can be formed uniformly. Further, since the ejection pressure of the jet stream is 10 to 200 kgf / cm ^2, pre-treatment effect for forming a more uniform anti-corrosion film is increased.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view illustrating a method for forming a rust-preventive film on a copper or copper alloy material according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a conventional rust prevention treatment method using BTA.

[Explanation of symbols]

 11; injection port 12; discharge port 13; pretreatment container 14; wire rod

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yoji Koike 1-5-1, Kiba, Koto-ku, Tokyo Inside Fujikura Co., Ltd. (56) References JP-A-7-48684 (JP, A) JP-A-63- 243289 (JP, A) JP-A-53-129134 (JP, A) JP-A-1-132783 (JP, A) JP-A-57-5882 (JP, A) "Corrosion science and anticorrosion technology", No. 297- Page 299, 14.2.3E (Corona, February 28, 1969) (58) Fields investigated (Int. Cl. ⁷ , DB name) C23F 11/00 C23G 1/00

Claims (1)

(57) [Claims] 1. A jet pressure of 10 to 200 kgf / cm.
² Spray hot water of 60 ° C or higher onto the drawn copper or copper alloy material by jet jet to form a copper oxide layer on the surface.
After forming , the copper or copper alloy material is treated with a solution containing benzotriazole or a derivative thereof.