JP3032107B2 - Rust prevention method for copper or copper alloy strip - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for rust-preventing copper or copper alloy strips for preventing discoloration of copper or copper alloy strips.

[0002]

2. Description of the Related Art Copper or copper alloy strips are manufactured by cutting a plate into narrow strips using a slitter. Conventionally, triazoles such as benzotriazole (BTA) and tritriazole (TTA), thiazoles, imidazoles, diols and other mercaptans have been used as the main rust inhibitor for copper. .

[0003] However, the copper alloy strip treated only with the main rust preventive agent removes a rust preventive film due to rubbing at the time of width cutting of the plate by a slitter, and discoloration may occur from the portion.
There is a demand for the formation of a rust-preventive film with a further improved rust-preventive effect.

For this reason, commercially available rust preventives contain two or three kinds of rust preventive aids, lubricating agents or surfactants in addition to the main rust preventive. The rust prevention effect is improved by adding a imparting agent or a surfactant.

The main rust inhibitor is benzotriazole (BTA)
And triazoles such as tritriazole (TTA),
Thiazoles or imidazoles are considered to be chemically reacted with the copper component on the surface of the treated material and to cover the copper surface as a chelate compound. This chelate compound layer has a water-repellent effect as a rust preventive coating, and prevents oxidation and discoloration of copper.

Conventionally, these main rust preventives have been dissolved in an aqueous solution or an organic solvent solution and treated by dipping, coating or steam, but all have problems.

Aqueous solutions are safe and can be processed reliably, and are used for processing high quality products. However, in the aqueous solution treatment, a pretreatment and a post-drying step are indispensable, and the treatment line becomes long. In addition, moisture has an effect of accelerating discoloration, and there is a problem that when a location with high humidity is generated, discoloration is preferentially performed from there.

The organic solvent solution can be easily used because the line is shorter and the humidity does not increase as compared with the use of an aqueous solution. However, the organic solvent solution is toxic and flammable. There is a problem. Recently, destruction of the ozone layer by an organic solvent has also become a problem, and regulations on the use of organic solvents have been tightened.

Further, even if the above-mentioned commercially available rust preventive agent is used for rust preventive treatment, discoloration still occurs, and the rust preventive film formed by the treatment with the conventional rust preventive agent has a width by a slitter. It cannot be said that it is a sufficient rust-proof coating against rubbing of the slitter blade during cutting.

Further, when the rust-preventive film is formed thick, there is a concern that a user may adversely affect a manufacturing process when manufacturing a product using the copper or copper alloy strip.

On the other hand, as a technique capable of solving these disadvantages, a technique has been proposed in which an annealed copper-based coil is held in a vacuum vessel and treated with dry air or gas containing a vaporizable rust preventive ( JP-B-63-67548).

[0012]

However, when the copper-based coil is held in a vacuum vessel and treated with dry air or gas containing a vaporizable rust preventive as described above,
Since the copper-based strip coil needs to be held in a separate container, productivity is reduced. Further, in the above-mentioned prior art, a vacuum state is set in order to process a narrow gap between the coils. However, if the vacuum state is used or a gas is used, there is a problem that the manufacturing cost increases.

[0013] The present invention has been made in view of the above problems, and it is possible to prevent the occurrence of discoloration due to the slitter process without lowering the productivity and without increasing the manufacturing cost. Another object of the present invention is to provide a method for rust-proofing copper alloy strips.

[0014]

According to the present invention, there is provided a method for rust-preventing copper or copper alloy strips, which is used in a copper or copper alloy strip production line for cutting a copper or copper alloy strip into a plurality of strips. Before the step, during the slitter step or after the slitter step, benzotriazole alone or its derivative
A rust inhibitor consisting of 50 to 200 ° C
And a gas obtained by vaporizing, preheated to a temperature of 50 to 200 ° C.
It was brought into contact by spraying the copper or copper alloy strip, the copper
Alternatively, after the copper alloy strip is subjected to a rust-proof treatment, the copper or copper alloy strip is packed.

[0015]

[0016]

According to the present invention, JIS Z151
It can have properties equivalent to those of the vaporizing rust inhibitor specified in No. 9. JIS Z 1519 relates to powder used for preventing rusting of steel. A vaporized rust inhibitor is a compound having sublimability at room temperature and having an effect of preventing rusting or a mixture containing the compound as a main component. And is not harmful to the human body in normal handling.

The present invention is to provide a copper or copper alloy strip which does not cause discoloration by incorporating the rust-preventing effect of the vaporized rust-preventing agent into a line of a slitter process. The copper or copper alloy strip is continuously rust-proofed in the line. That is, the present invention does not require a vacuum state or the use of a special gas (argon gas or nitrogen gas).

The present inventors have made intensive studies to utilize a sublimation gas of a vaporized rust inhibitor as a rust preventive treatment that can be performed in a narrower space without using an organic solvent. In some cases, discoloration occurs in products that should have been reliably treated with the rust-preventive aqueous solution, and as a result of investigating the cause, it has been found that rubbing caused in the slitter process reduces the discoloration prevention effect. In addition, the present inventors have found that the gas obtained by forcibly heating the vaporized rust preventive agent can repair the rust preventive film in the portion where the rust preventive film has been damaged by rubbing with the slitter. . The present invention has been completed under such a background.

The vaporizing rust preventive is impregnated into the packing paper or put in a solid form in the packing container, and utilizes the property of sublimation at room temperature to allow the vapor to float in the packing container to exhibit the rust preventing effect. It can also be done.

In order to forcibly heat the vaporized rust inhibitor,
It is preferable to blow hot air or directly heat with a hot plate to heat to a temperature close to or higher than the melting point, instead of the usual method of sublimation little by little at normal temperature.

Usually, the rust-preventive coating is repaired after the slitting step, but by introducing a gas obtained by forcibly heating the vaporized rust-preventive agent into the current rust-preventive treatment line, Rust prevention treatment may be applied.

When the vaporizing rust inhibitor is benzotriazole alone or its derivative, it is preferable to blow a gas obtained by heating it to a temperature of 50 to 200 ° C. onto the copper or copper alloy strip. If the heating temperature is lower than 50 ° C., a sufficient rust preventive effect is not provided to the copper strip. Further, heating to a temperature exceeding 200 ° C. does not effectively act on the rust-preventing effect because the rust-preventing agent is only consumed greatly. For this reason, when benzotriazole alone or its derivative is used,
To 200 ° C.

If the copper or copper alloy strip is preheated before the vaporized rust preventive is brought into contact with the vaporized gas, the rust preventive effect is remarkable. The preheating temperature of the copper or copper alloy strip is 50 ° C. or higher,
A temperature of 00 ° C or less is desirable. When the preheating temperature is lower than 50 ° C., the effect of promoting the imparting of the rust prevention effect is small. If the preheating temperature exceeds 200 ° C., the copper surface may be affected by heat, and the properties of copper may change. As described above, it is preferable to keep the temperature of the copper strip constant before the treatment with the gas of the vaporized rust preventive agent, in order to make the amount of the vaporized rust preventive agent uniform and to control the adhesion speed.

When the vaporizing rust inhibitor is vaporized by hot air, the copper sheet can be heated by the hot air at the same time. If the copper strip is not preheated, the temperature of the copper strip is low. Therefore, even if the copper strip is heated with hot air simultaneously with the rust prevention treatment, the time required for the treatment with the vaporized rust inhibitor gas is 5 seconds or more. On the other hand, if the copper is preheated, it is possible to perform the rust-proofing treatment in a short time.

Therefore, when sufficient processing time cannot be obtained due to an increase in line speed and lack of processing space, and in a line affected by a change in temperature, copper is preheated to control the deposition rate. It is necessary to keep the temperature constant. There are various methods for preheating the copper alloy, such as a method of heating with hot air and a method of contacting with a hot roll.

Also, as in the present invention, the effect of improving the water repellency can be obtained by vaporizing the vaporized rust preventive agent and bringing the gas into contact with copper or a copper alloy strip for rust preventive treatment. The component of the vaporized rust inhibitor imparting water repellency is, for example, benzotriazole. Further, even if another main rust inhibitor is used, a water repellent effect can be obtained.

[0027]

Next, the results of a test on the rust-preventing effect of the examples of the present invention will be specifically described in comparison with comparative examples.

First, an apparatus used for the rust prevention treatment will be described.

FIG. 1 is a schematic diagram of a slitter line showing an embodiment of the present invention.

The copper or copper alloy plate 1 drawn from the copper or copper alloy plate roll 12 is supplied to the finger 2.
In the finger 2, circular blades and plate holders are alternately arranged. In the finger 2, the plate 1 is cut into a plurality of narrow strips 11. Plate 1 has a width of about 700
mm, the width of the strip 11 is about 30 mm.

The plurality of strips 11 are wound around the strip roll 13 in a line in the width direction. In this case, a tension pad 3 is arranged between the finger 2 and the strip roll 13, and the tension pad 3 presses and presses the strip 11, thereby tensioning the strip 11 wound up by the roll 13. Is given.

In this embodiment, the tension pad 3
A vaporization rust prevention tank 4 is provided between the roll and the roll 13.
FIG. 2 shows that the vaporized rust preventive tank 7 contains a vaporized rust preventive agent 7, and the vaporized rust preventive agent 7 is heated to a predetermined temperature. Thereby, the vaporized rust preventive agent 7 is vaporized in the vaporized rust preventive tank 4, and the strip 1 passing through the vaporize rust preventive tank 4 is formed.
Gas 1 vaporized by the vaporized rust preventive agent 7 is sprayed by the nozzle 5 to come into contact with the rust preventive agent 7 to perform rust preventive treatment. Note that reference numeral 6
Reference numeral denotes an exhaust port for the gas that the vaporizing rust preventive agent 7 has vaporized.

In the present embodiment, the cleaned copper or copper alloy plate 1 is first treated with a normal rust preventive, and then, as shown in FIG. And copper and copper alloy strips having an excellent rust-preventing effect can be obtained by re-treating with a gas obtained by forcibly heating.

FIG. 3 shows a modification of the vaporization rust prevention tank 4.
That is, the vaporization rust prevention tank 4 is provided with a preheating tank 8 on the upstream side. The strip 11 is first preheated to a predetermined temperature in the preheating tank 8, and then comes into contact with the vaporized gas of the rust preventive agent 7 in the vaporization rust prevention tank 4.

The vaporization rust prevention tank 4 and the preheating tank 8
May be provided on the upstream side of the finger 2 for cutting the plate 1, or such a processing portion may be provided on the finger 2 itself.

Next, the results of a test in which rust prevention treatment was performed on copper or copper alloy strips using such an apparatus will be described.

Example 1 A copper alloy strip was sequentially subjected to alkali degreasing and acid cleaning by a conventional method. Then, it was immersed in a commercially available aqueous solution having a rust inhibitor concentration of 0.2% at 70 ° C. for 5 seconds and dried. Next, width cutting was performed on the slitter line. After the width cutting, a gas obtained by heating the benzotriazole simple substance to 90 ° C. was sprayed onto the copper alloy strip for 3 seconds, and then wound.

The rust-proofed product obtained by the above method showed no discoloration in the sulfur dioxide gas test and the constant temperature / humidity test, and the rust prevention effect was good. The conditions of the sulfurous acid gas test and the constant temperature / humidity test are as follows.

[Sulfurous acid gas test] Sulfurous acid gas concentration 10 pp
The rust-proof plate was hung in an atmosphere of m, temperature of 40 ° C. and humidity of 80% RH, and the discoloration after 15 hours was evaluated.

[Constant Temperature and Humidity Test] The rust-proofed plates were overlaid, tightened and set at a torque of 10 kg cm, and heated to a temperature of 40 kg.
The discoloration was evaluated after 96 hours storage in an atmosphere of 80 ° C. and 80% RH.

COMPARATIVE EXAMPLE 1 A copper alloy strip was sequentially subjected to alkali degreasing and acid cleaning by a conventional method. Then, it was immersed in a commercially available aqueous solution having a rust inhibitor concentration of 0.2% at 70 ° C. for 5 seconds and dried. Next, width cutting was performed on the slitter line. Rust prevention treatment with vaporized gas is not performed.

As described above, in the product subjected to only the rust-proofing treatment with a commercially available rust-preventive agent solution, discoloration occurred in the rubbed portion during slitting in the sulfur dioxide gas test.

Examples 2 to 5 and Comparative Examples 2 to 5 The same procedure as in Example 1 was carried out except that the copper alloy strip was preheated. However, the vaporization temperature of benzotriazole (BTA) and the preheating temperature of the copper alloy strip were set as shown in Table 1 below. The BTA processing time is 3 seconds. The column of test results in Table 1 below is the result of a constant temperature and humidity test, which was evaluated after being stored in an atmosphere at a temperature of 40 ° C. and a humidity of 80% RH for 96 hours. The sulfurous acid gas test was also performed under the same conditions as in Example 1;
For No. 5, similarly good results were obtained.

[0044]

[Table 1]

Examples 2 to 5 had excellent water repellency and rust-preventive effect, and did not undergo discoloration in the sulfurous acid gas test and the constant temperature / humidity test. Also, benzotriazole (BTA)
And the surface condition of the copper alloy strip are good, which is a treatment condition suitable for practical use. Examples 2 to 5 are BT
Even if the treatment time in A was as short as 5 seconds or less, a good rust prevention effect was exhibited.

On the other hand, in Comparative Examples 2 and 3, since the copper alloy preheating temperature and the BTA vaporization temperature were low, respectively, the amount of the vaporized rust inhibitor was small, and partial discoloration occurred in the sulfurous acid gas test and the constant temperature and constant humidity test. However, when the treatment time in BTA was 5 seconds or less, the rust prevention effect was not sufficient.

In Comparative Examples 4 and 5, the copper alloy preheating temperature and B
Since the TA vaporization temperature was high, the copper alloy strip was thermally affected or benzotriazole was greatly consumed, and was not suitable for practical use.

According to the present invention, since the copper alloy strip is continuously processed in the line and does not require a vacuum or a special gas (argon gas or nitrogen gas), it can be processed at low cost.

[0049]

As described above, according to the present invention, the rubbing portion of the slitter blade in the slitter process is a gas obtained by forcibly heating the vaporizing rust preventive agent before, during or after the damage. By processing in line immediately after damage,
Copper and copper alloy strips having excellent rust prevention effect can be obtained with high productivity and low cost, discoloration occurring in copper or copper alloy strips is reduced, and quality reliability can be improved. .

The gas treatment of the vaporized rust preventive is more suitable for restoration than the rust preventive treatment using an aqueous solution or an organic solvent, and can be safely performed in a narrow space. Further, the copper alloy strip treated with the vaporized rust inhibitor gas has excellent water repellency.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a slitter line showing an embodiment of the present invention.

FIG. 2 is a schematic view showing an example of the inside of a vaporization rust prevention tank.

FIG. 3 is a schematic view showing an example of a vaporization rust prevention tank provided with a preheating tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1; Copper or copper alloy plate 2; Finger 3; Tension pad 4; Vaporization rust prevention tank 5; Spray nozzle 6;

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-61-15988 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C23F 11/02 C22F 1/08

Claims (1)

(57) [Claims] 1. A copper or copper alloy strip production line for cutting a copper or copper alloy plate into a plurality of strips by a slitter,
Before the slitter step, during the slitter step or after the slitter step, the vaporized rust inhibitor consisting of a benzotriazole simple substance or a derivative thereof is heated to a temperature of 50 to 200 ° C. to evaporate the gas to 50 to 200 ° C. The copper or copper alloy strip preheated to a temperature of 200 ° C. is sprayed and brought into contact with the copper or copper alloy strip.
A method for rust-preventing copper or copper alloy strips, comprising packing the copper or copper alloy strip after subjecting the metal strip to rust prevention treatment.