JPH09209180A - Rust preventive treatment of copper or copper alloy material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rust preventive treatment method for a copper or copper alloy material which is capable of rapidly and sufficiently removing acids, oil-components, etc., on the surfaces as a pretreatment stage for formation of the rust preventive films and uniformly forms secure rust preventive films in a subsequent stage for forming the rust preventive films. SOLUTION: The copper or copper alloy material is passed through the inside of a box-shaped pretreating vessel 13 as the pretreatment for formation of the rust preventive films by a soln. contg. a rust preventive. An injection inlet 11 of the soln. contg. solid particulates, such as alumina particles, is formed in the upper part of the vessel 13 and a discharge port 12 for the same is formed in the lower wall. Since holes to be passed with the copper or copper alloy material 14 are formed in the side walls of the vessel 13, the copper or copper alloy material is pretreated while passing the inside of the vessel 13 in an arrow direction. When the liquid contg. the solid particulates of alumina, etc., is injected by jet flow from the injection inlet 11, the deposits, such as acids and oil-components, on the surfaces of the copper or copper alloy material 14 are removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rust-preventing method for copper or copper alloy materials such as plates, wires and pipes. Provided is a method for rust-preventing a copper or copper alloy material, which can be sufficiently removed in a short time, and which makes it possible to uniformly form a strong rust-preventive film in a subsequent rust-proof film forming step.

[0002]

2. Description of the Related Art Benzotriazole (BTA) or its derivative is generally used as an anticorrosive agent for copper or copper alloy materials. Hereinafter, BTA and its derivatives are collectively referred to simply as BTA. The rust preventive 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, although a thin film of copper oxide (Cu ₂ O) of atomic order is naturally formed on the surface of copper or copper alloy material, BTA molecules form a strong coordination bond with this copper oxide. At the same time, BTA molecules also form covalent bonds to form a strong BTA polymer film on the surface of the copper or copper alloy material. The BTA polymer film formed in this manner has excellent adhesion to copper or a copper alloy material, and also has extremely excellent corrosion resistance. Protect.

FIG. 2 is a block diagram showing a conventional rustproofing method using BTA. First, a copper or copper alloy material (treated material) processed into a shape of a plate, wire, pipe or the like is degreased by pickling (step 1), washed with water (step 2), and then dried once (step 3). ). The pickling in step 1 is carried out by using sulfuric acid, nitric acid, phosphoric acid, chromic acid or the like for the purpose of removing oxides (CuO) on the surface of the treated material and processing lubricating oil. In addition, the drying in step 3
By this drying treatment, a thin copper oxide layer is formed on the surface of the treated material, so that BTA easily reacts with the treated material. Then, the treatment material is immersed in a solution containing BTA, or this solution is applied to the treatment material and subjected to BTA treatment (step 4), and finally dried (step 5) to obtain a product. For the BTA treatment in step 4, a solution prepared by dissolving BTA in a solvent such as water, alcohol or trichloroethane is used. This rustproofing solution is 50 to 8
It is preferably 0 ° C.

In the steps 1 to 5, if the surface of the treated material is not coated with the rust preventive film to a sufficient thickness, it is washed again with water in step 2, dried in step 3, and BTA treated in step 4. And the drying process of step 5 is performed to form a rust preventive film having a sufficient thickness. In addition, step 5
The BTA polymer layer formed is dried to make it stronger. For this drying treatment, hot air at 150 ° C. or lower can be used.

Thus, steps 2 to 5 shown in FIG.
In practice, it is preferable to repeat the series of steps 2 or more times. In that case, after the step 5, the weak pickling can be performed, and the steps 2 to 5 can be performed after the pickling. As a result, even if a complete BTA rustproof film is not formed by one treatment,
By the second and subsequent treatments, a complete BTA rustproof film can be formed.

[0006]

However, in such a rust preventive treatment method, the effect of pickling cannot be sufficiently obtained, and oxides and processing lubricating oil on the surface of the treated material are completely removed. It has not been. Therefore, even if the above steps 2 to 5 are repeated a plurality of times, a complete BTA protective film is not formed and a defective portion remains. Then, this defective portion becomes a starting point, and corrosion or discoloration occurs. Moreover, in order to perform sufficient pickling on the treated material, a time loss occurs.

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

[0008]

A rust preventive treatment method for a copper or copper alloy material according to the present invention comprises a pretreatment step of spraying a liquid containing solid fine particles such as alumina onto the copper or copper alloy material by a jet jet, Alternatively, the method is characterized by having a rust preventive film forming step of forming a rust preventive film on the surface of the copper alloy material.

The jet pressure of this jet jet is preferably 10 to 200 kgf / cm ² .

The jet jet means that the jet of liquid is turbulent.

The BTA anticorrosive film has the property that it is easily formed on thin copper oxide (Cu ₂ O). Therefore,
In the present invention, as a pretreatment of the rust preventive film forming step, a liquid containing solid fine particles such as alumina particles is sprayed onto the treatment material by a jet jet to polish the surface of the treatment material. Then, the oxide (CuO) on the surface of the treated material, the processing lubricating oil, etc. can be completely removed, and a uniform thin copper oxide is formed on the surface of the treated material. Therefore, by performing this pretreatment, a strong rustproof film can be uniformly formed in the subsequent rustproof film forming step.

Further, in the present invention, the liquid containing solid fine particles such as alumina particles is caused to collide with the surface of the treated material at a high speed, so that a compressive stress can be applied to the surface of the treated material, which causes corrosion of the surface of the treated material. And fatigue can be prevented.

Further, in the present invention, the jet pressure of the jet jet is preferably 10 to 200 kgf / cm ² . This is because if the jet pressure is less than 10 kgf / cm ² , the effect of the jet jet cannot be obtained. On the other hand, if the ejection pressure exceeds 200 kgf / cm ² , erosion that mechanically damages the surface of the treated material due to the pressure of the liquid containing solid fine particles such as alumina particles is likely to occur. Also, 10 to 200 kgf / cm ²
With a pressure of, the process is easily carried out because a plunger pump capable of ejecting a liquid within this pressure range is generally commercially available.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the accompanying drawings. FIG. 1 is a schematic cross-sectional view showing a pretreatment step of a rust preventive treatment method for a copper or 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 pretreatment for forming an anticorrosive film, a wire 14 is passed through a pretreatment container 13 shown in FIG. This wire 14
Is processed into a desired diameter by passing through a wire drawing die, but since wire drawing is applied, processing lubricant oil and oxides remain on the surface of the wire 14. ing. Therefore, instead of pickling the treatment material, the treatment material is pretreated in the pretreatment container 13.

Pretreatment container 13 used in this embodiment
Has a box shape with a volume of about 100 cc, for example, and a hot water jet port 11 of 60 ° C. or higher is formed on the upper wall, and a discharge port 12 is formed on the lower wall. In addition, holes are formed on both side walls of the pretreatment container 13 through which the wire 14 passes, and the distance between the side walls is, for example, 0.1 m. Therefore, the wire rod 14 is pretreated in the pretreatment container 13 at a portion of 0.1 m while passing through the pretreatment container 13 in the arrow direction. The wire 14 is driven so as to move in the arrow direction by a feeding or winding device (not shown) arranged on the upstream side or the downstream side, respectively. Then, the wire 14 is subjected to a treatment for forming a rust preventive film with a solution containing a rust preventive agent.

In the method of this embodiment which uses the pretreatment container 13 thus constructed, the wire rod 14 is moved in the direction of the arrow and, for example, 50 kgf / cm from the injection port 11.
² Solid jet such as alumina particles 15
A liquid containing is injected into the pretreatment container 13. Then, this liquid collides with the surface of the wire 14 at a high speed, and the oxides and lubricant deposits on the surface are removed, and a thin copper oxide layer is likely to be uniformly formed on the surface of the wire. In this embodiment, the moving speed of the wire 14 is 600 m / min, that is, 10 m / sec. Therefore, the pretreatment time for the treated length of the wire 14 of 0.1 m is 0.01 seconds, and despite the short pretreatment time, the effect of removing oxides and lubricating oil is extremely high.

[0018]

EXAMPLES Examples of the rustproofing method for copper or copper alloy materials according to the present invention will be specifically described below in comparison with comparative examples.

First, test materials which were subjected to various anticorrosion treatments were prepared, and a sodium sulfide test was conducted on each test material. This sodium sulfide test is generally performed as a method for evaluating the rust preventive effect of copper or copper alloy materials.
The test material is immersed in a 0 ppm aqueous solution of sodium sulfide, and the degree of discoloration of the test material after a certain period of time is evaluated.
The results of these evaluations are shown in Table 1 below. However, Example N
o. In No. 1, the wire was pretreated according to the method of this example,
After washing with water in the same manner as before, dry them with hot air,
Then, a rust preventive film was formed using BTA as a rust preventive and dried. Comparative Example No. Example No. 2 was obtained by subjecting the wire rod to pretreatment by pickling and then Example No. In the same manner as in No. 1, water washing, drying and rust preventive film forming treatment were performed.
Example No. 1 and Comparative Example No. No. 2 was treated continuously, and the moving speed of the wire rod in the pretreatment process was 600 m / min. In addition, as a batch treatment capable of forming the best rust preventive film, the wire rod was immersed in an acidic solution for 10 minutes and sufficiently washed with running water, and then the sample of Example No. The test material subjected to the rust preventive film forming treatment similar to that of Comparative Example No. It was set to 3. In these Comparative Examples and Examples, the wire rod was a tough pitch copper wire having a diameter of 1.0 mm, and the hot air drying condition was 30 seconds in a stationary state. In addition, the rust preventive film forming treatment is performed at room temperature at 0.1.
The wire rod was immersed in a 1% BTA aqueous solution for 1 minute. In the evaluation result column of the sodium sulfide test shown in Table 1 below, ◯ means that the surface of the test material did not discolor at all, Δ means that the surface was slightly discolored, and x means that the surface was significantly discolored.

[0020]

[Table 1]

As shown in Table 1 above, Comparative Example No. With respect to No. 2, discoloration occurred on the surface of the test material in the immersion time of 1.5 minutes, and the discoloration of the surface of the test material progressed over time. This indicates that the oxide on the surface of the test material and the processed lubricating oil were not completely removed by pickling, so that a complete rustproof film was not formed. In addition, as a batch treatment, a comparative example No. 1 was prepared in which a test material was prepared by a method capable of forming the best rust preventive film. In No. 3, discoloration occurred only after immersion for 3 minutes, and the formation state of the rust preventive film was good. However, since this method uses a pickling method by immersion in an acidic solution for 10 minutes, the treatment time is extremely long as compared with other comparative examples and examples, and it is difficult to actually use it. is there.

On the other hand, Example No. For Comparative Example No. 1, although the discoloration of the surface of the test material occurred when the immersion in the aqueous solution of sodium sulfide had passed for 2.5 minutes, the pretreatment time was extremely short. Compared with No. 2, it exhibited an excellent rust prevention effect.

Then, the same sodium sulfide test was carried out on the wire rod which had been pretreated by spraying the liquid containing the solid fine particles onto the wire rod at the ejection pressure shown in Table 2 below. Regarding the conditions other than the jet pressure of the jet jet, Example No. 1
Same conditions as. The results of these evaluations are also shown in Table 2 below.

[0024]

[Table 2]

As shown in Table 2 above, Example No. ¹ in which the jet pressure of the jet jet was 10 to 200 kgf / cm ² . 1
Nos. 1 to 14 were as effective as or better than those obtained by subjecting the wire to pretreatment by pickling, and no discoloration or the like occurred until the immersion time of 2 to 2.5 minutes.

On the other hand, Comparative Example No. 3 in which the jet pressure of the jet jet is less than the lower limit of the range of the present invention. In No. 15, the effect of using solid fine particles was not obtained because the ejection pressure was small, and discoloration occurred in the immersion time of 1 minute. Further, Comparative Example No. 1 in which the ejection pressure exceeded the upper limit of the range of the present invention. No. 16 excessively roughens the surface of the wire rod because the pressure of the solid fine particles colliding with the surface of the wire rod is large. As with No. 15, discoloration occurred after 1 minute of immersion.

Although the wire rod made of copper or copper alloy is used in this embodiment, the same effect can be obtained by using a plate or pipe other than the wire rod.

Further, as the rust preventive agent, in addition to benzotriazole or its derivative, a rust preventive agent having another molecular chain such as benzimidazole type can be used.

[0029]

As described in detail above, according to the method of the present invention, a liquid containing solid fine particles is sprayed onto a copper or copper alloy material by a jet jet to perform a pretreatment for forming a rust preventive film. Oxides on the surface of the copper alloy material, working lubricating oil, etc. can be completely removed in a short time. Therefore, a strong rustproof film can be uniformly formed in the rustproof film forming step after the pretreatment. Further, by spraying a liquid containing solid fine particles onto a copper or copper alloy material by a jet jet, a compressive stress is applied to the surface of the copper or copper alloy material, so that corrosion and fatigue of this surface can be prevented. Furthermore, the jet pressure of the jet jet is 10 to 200 kgf /
If it is cm ² , the pretreatment effect for forming a more uniform rust preventive film is enhanced.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a pretreatment step of a rust preventive treatment method for a copper or copper alloy material according to an example of the present invention.

FIG. 2 is a block diagram showing a conventional rust preventive treatment method using BTA.

[Explanation of symbols]

 11: injection port 12: discharge port 13: pretreatment container 14; wire rod 15: solid fine particles

Claims (2)

[Claims] 1. A pretreatment step of spraying a liquid containing solid fine particles onto a copper or copper alloy material by a jet jet flow, and a rust preventive film forming step of forming a rust preventive film on the surface of the copper or copper alloy material. A method for rust prevention of copper or copper alloy material. 2. The rust preventive treatment method for copper or copper alloy material according to claim 1, wherein the jet pressure of the jet jet is 10 to 200 kgf / cm ² .