JPH0688258A - Two-stage rust preventive treatment of copper or copper alloy - Google Patents

Abstract

PURPOSE:To provide a two-stage rust preventive treatment method for a copper or copper alloy material which intensifies rubbing at the time of cutting by a slitter and at the time of packaging and obviates the generation of discoloration by providing a main rust preventive with lubricity without degrading its rust preventive effect. CONSTITUTION:The copper or copper alloy material in the method for subjecting the copper or copper alloy material to the rust preventive treatment is treated with a liquid contg. a rust preventive of a reaction type in a first rust preventive tank 4 and is then treated with a liquid contg. the component of an adsorption type for imparting the lubricity in a second rust preventive tank 5. The liquid contg. the rust preventive of the reaction type may be formed as a liquid contg. 50 to 500ppm benzotriazole deriv. The liquid contg. the component of the adsorption type for imparting the lubricity may be formed as a liquid contg. a nonionic surfactant of a polyether type and alkanol amine. The liquid contg. the rust preventive of the reaction type may be prepd. as a pickling liquid as well.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-stage rust preventive treatment method for a copper or copper alloy material which prevents discoloration of the copper or copper alloy material.

[0002]

2. Description of the Related Art Conventionally, main rust preventives for copper include benzotriazole (BTA) and tritriazole (TTA) and other triazoles, and thiazoles, imidazoles and diol-based mercaptan-based ones. .

However, the copper alloy strip treated only with these main rust preventive agents may have its rust preventive coating removed by rubbing at the time of cutting with a slitter or packing, and discoloration may occur from that portion. Therefore, there is a demand for a material having a further enhanced rust prevention effect.

In order to meet such demands, commercially available rust preventives contain two to three kinds of rust preventive aids and a lubricant or a surfactant in addition to the main rust preventive. In this way, the rust preventive effect is improved by adding the rust preventive aid, the lubricity imparting agent or the surfactant.

JP-A-50-21947 and JP-A-50-21948 disclose corrosion prevention of water-based metals obtained by mixing a low molecular weight polymer with phosphate, polyacrylate / acrylamide, hydrazine, benzotriazole or mercaptobenzothiazole. Agents have been proposed.

It has also been reported that various rust preventive aids such as a polyester type plasticizer (Japanese Patent Publication No. 3-71517) or hydroxamic acid (Japanese Patent Publication No. 54-410) are added to a benzotriazole solution. .

Further, in Japanese Examined Patent Publication No. 3-43349, a copper alloy wire is treated with a benzotriazole type rust preventive agent and then treated with a mercaptan type rust preventive agent in a two-stage treatment with a main rust preventive agent. By doing so, it is reported that discoloration of the copper alloy wire can be prevented even if the copper alloy wire is left for a long time in an atmosphere of extreme material such as high temperature and high humidity.

However, discoloration still occurs even when treated with a commercially available rust preventive agent, and improvement in rust preventive technique is desired.

[0009]

However, even when treated with these conventional rust preventive agents, discoloration still occurs, and these conventional rust preventive agents are not satisfactory in terms of rust preventive effect. There wasn't.

That is, the above-mentioned copper or copper alloy material treated only with the main anticorrosive agent is vulnerable to rubbing at the time of cutting with a slitter or at the time of packaging, and there is a problem that discoloration occurs from the rubbed portion.

On the other hand, in order to prevent discoloration due to this rubbing, when a few kinds of rust preventive aids and lubrication agents or surfactants are added, the components for strengthening the rubbing are mainly There is a problem that the anticorrosive effect of the anticorrosive agent is reduced.

Further, the mercaptan type rust preventive agent has a peculiar offensive odor, and since it becomes an emulsion in an aqueous solution, it is difficult to use.

The present invention has been made in view of the above problems, and has a lubricating property without reducing the anticorrosive effect of the main anticorrosive agent, and is strong against rubbing at the time of cutting by a slitter and packing. However, an object of the present invention is to provide a two-stage rust preventive treatment method for a copper or copper alloy material in which discoloration does not occur.

[0014]

A two-stage anticorrosion treatment method for copper or copper alloy material according to the present invention is a method of anticorrosion treatment for copper or copper alloy material, wherein the copper or copper alloy material is of a reaction type. It is characterized in that it is treated with a liquid containing a rust preventive agent, and then treated with a liquid containing a component that imparts adsorption type lubricity.

As the liquid containing the reaction type rust preventive, there is a liquid containing 50 to 500 ppm of a benzotriazole derivative, and as the liquid containing a component imparting lubricity of adsorption type, a polyether nonionic surface active agent is used. There is a liquid containing an agent and an alkanolamine.

Further, the liquid containing the reaction type rust preventive may be an acid cleaning liquid containing sulfuric acid or the like.

[0017]

The present inventors have conducted extensive studies on the rust preventive agent for copper or copper alloy materials and their rust preventive effect, and as a result, the additive component for strengthening the rust preventive material against rubbing prevents discoloration of the rubbed portion. It was confirmed that this additive component inhibits the formation of the rust preventive film of the main rust preventive agent.
The present invention has been made based on such knowledge.

The main anticorrosive agent is benzotriazole (BT
In addition to triazoles such as A) and tritriazole (TTA), there are thiazoles and imidazoles, but these main rust preventives chemically react with the copper component on the surface of the treated material,
The generated chelate compound covers the copper surface. This chelate compound layer has a water repellent effect as an anticorrosive film and prevents the copper from changing and discoloring.

On the other hand, the component for strengthening the rustproofing material against rubbing includes organic polymers such as polyethylene glycol and polypropylene glycol, or polyether nonionic surfactants. These components form an adsorption layer on the chelate compound layer or in the gaps, and have the effect of protecting the rust preventive film.

In addition, as a material for strengthening the anticorrosion treatment material against rubbing, a lubricating component such as an ethylene oxide derivative serving as a base of a lubricating oil or a hydraulic oil, and a polyester plasticizer (Japanese Patent Publication No. 3-71517) ), An epoxy plasticizer (Japanese Patent Publication No. 3-71516) and a phthalic acid plasticizer (Japanese Patent Publication No.
-71515) is also effective. However, if the effect of protecting the rust-preventive coating is too high, there may arise a problem that cleaning becomes difficult in the subsequent steps such as plating, chemical conversion treatment, soldering and bonding.

As described above, when treated by mixing the main rust preventive and the component having lubricity, the non-rubbed portion is more likely to be discolored and the rubbed portion is discolored as compared with the treatment agent containing only the main rust preventive. It's hard to do. Therefore, the lubricating component has the advantage of protecting the rust preventive film from rubbing, but on the contrary, it inhibits the chemical reaction between the main rust preventive component and the copper surface. Therefore, in the present invention, the main rust preventive agent and the lubricating component are divided into two stages of rust preventive treatment.

FIG. 1 is a schematic view of an anticorrosion treatment line showing an example of the method of the present invention. The strip 1 is unwound from the coil of the strip 1 of the copper or copper alloy plate mounted on the feeding roll 8 and supplied to the acid cleaning tank 2. The strip is this acid cleaning tank 2
After being pickled, it is washed in the washing tank 3 and then supplied to the first rust preventive tank 4. The strip material 1 is treated with the reaction type main rust preventive agent in the first rust preventive tank 4 to form a chelate-like rust preventive film on the surface thereof.

After that, the strip 1 is supplied to the second rust preventive tank 5, and treated in this second rust preventive tank 5 with a rust preventive agent containing an adsorption type lubricating component.

Since the processing is performed in two stages as described above,
The adsorption-type lubricating component does not inhibit the formation of a chelate-like film formed on the surface of the copper or copper alloy material by the reaction-type main rust preventive agent, and a good rust preventive effect can be obtained.

Further, since the lubricating layer for covering and protecting the gap and the surface is sequentially formed on the outside of the chelate-like anticorrosive film by the treatment of the second step, it is rubbed during cutting by the slitter and packing. A strong anticorrosive film that does not peel off is formed. After that, the strip 1 is a draining air nozzle 6
The water on the surface is blown off by means of the above, then dried by the drying furnace 7, and then wound on the winding roll 9.

Although the concentration of the main rust preventive agent, for example, benzotriazole, is effective even in a small amount, it is preferably 50 to 500 ppm. The concentration of benzotriazole in a liquid containing a reaction type rust preventive is less than 50 ppm and the rust preventive effect is weak. On the other hand, if it exceeds 500 ppm, uneven treatment may occur, and even if the concentration is further increased, the rust preventive effect is not improved so much.

Usually, as shown in FIG. 1, after pickling in the pickling line, rust prevention is performed after washing with water. If not, the main rust preventive may be added to the water washing layer 3 in front of the rust preventive tank 4 or the acid cleaning tank 2. The anticorrosive film is a chelate film and does not reduce the effect of acid cleaning. Further, once the rust preventive film is formed by reacting with copper, the rust preventive film is not removed by washing with water.

In fact, it was confirmed that the addition of a reaction type rust preventive agent to the acid cleaning tank improved the rust preventive effect. However, it is necessary to carry out sufficient water washing after the acid washing and to prevent acid components (such as sulfate radicals) from remaining on the surface by treatment with a liquid containing a component that imparts adsorption type lubricity.

An acid-washed and water-washed copper or copper alloy strip is first treated with a liquid containing a main anticorrosive agent, and then treated with a liquid containing a component which imparts lubricity, thereby providing an excellent antirust effect. A copper or copper alloy strip is obtained.

It is desirable to add about 10 to 100 ppm of a component imparting lubricity, such as polyethylene glycol. If the concentration is too low, the effect of imparting lubricity decreases,
On the other hand, if the concentration is too high, this component adheres too much to the surface and is difficult to remove, and since the adsorptivity is high, dew condensation is likely to occur in a high temperature and high humidity environment.

Further, the main rust preventive agent and the rust preventive auxiliary agent may be simultaneously added to the liquid containing the component imparting lubricity. Examples of the anticorrosion aid include alkanolamines, borates, carboxylic acids, polyvalent amines, organic acids and their derivatives.

A copper or copper alloy strip having particularly good lubricity is obtained when the liquid containing an adsorption type component imparting lubricity is a liquid containing a polyether nonionic surfactant and an alkanolamine. To be Polyether-based nonionic surfactants have the properties of lubricity, low surface tension, uniform surface treatment, and low volatility and stability in aqueous solution. In addition, alkanolamine has a water-repellent property and also has a buffering action for keeping the liquid at pH 6 to 9, and has an effect of stabilizing the structure of the rust preventive film.

As described above, the rust-preventive treatment is divided into two steps. First, the reaction-type main rust-preventive agent is applied to the material to be treated to form a chelate film, and then the rust-preventive agent containing the adsorption-type lubricating component is used in two stages. It is possible to obtain a copper or copper alloy material that is resistant to change and discoloration.

[0034]

EXAMPLES Example 1 Phosphor bronze was sequentially subjected to alkaline degreasing cleaning and acid cleaning by a conventional method. Then, benzotriazole concentration 300p
Immerse in pm aqueous solution for 5 seconds, then in polyethylene glycol concentration 30ppm, triethanolamine concentration 300ppm, caprylic acid concentration 100ppm aqueous solution (70 ℃) for 5 seconds,
Dried.

The product subjected to anticorrosion treatment by the above method did not cause discoloration in the sulfurous acid gas test and the wet cycle test, and had a good anticorrosion effect.

Further, in order to investigate the anticorrosive effect of the rubbed portion, a similar discoloration acceleration test was conducted on the rubbed material through a slitter process. As a result, the material of Example 1 had a lubricity on the surface, so that discoloration did not occur even after slitting.

However, the sulfurous acid gas test is based on the sulfurous acid gas concentration.
The rust-proofed plate was hung in an atmosphere of 10 ppm and a temperature of 40 ° C. and a humidity of 80% RH, and the discoloration state was evaluated after 15 hours.

The wet cycle test is conducted according to JIS C.
A combined temperature and humidity cycle test was conducted for 240 hours in accordance with the above. Evaluation of Anticorrosion Effect The test materials were evaluated by observing their appearance, observing with a microscope and measuring the gloss.

Table 1 below shows the evaluation test results of the rust preventive effect by the sulfurous acid gas test and the wet cycle test.
However, the judgment criteria for the sulfurous acid gas test material and the wet cycle test material are as follows.

Test method; (1) Observation of appearance Visually confirm the presence or absence of discoloration.

(2) Occurrence of dot discoloration The number of dot discolorations of 50 μm or more was measured with a microscope (50 times) to obtain the dot discoloration density (pieces / mm ² ).

(3) Gloss measurement The specular reflectance is measured at 45 ° parallel to the rolling direction (JIS
Z 8741).

Evaluation method: Remarkable discoloration visually observed (dot discoloration has grown and discoloration has occurred over the entire surface)
X, no noticeable discoloration was observed, but 0.02 pieces / mm ² or more of point discoloration of 50 μm or more was observed by microscope observation, and gloss decreased by 15% or more.
The number of occurrence of dot discoloration was less than 0.02 pieces / mm ² and the decrease in gloss was less than 15%, which is indicated by ◯.

[0044]

[Table 1]

Example 2 A Cu-Ni-Si-based copper alloy was sequentially subjected to alkaline degreasing cleaning and acid cleaning by a conventional method. Then, immerse in an aqueous solution of imidazole concentration 100ppm, caprylic acid concentration 50ppm for 5 seconds, then dinclohexylamine concentration 30ppm, polyacrylate concentration 30ppm, benzotriazole concentration 50ppm
It was dipped in the aqueous solution (70 ° C.) for 5 seconds and dried.

Example 3 Phosphor bronze was sequentially subjected to alkaline degreasing cleaning and water cleaning by a conventional method. Then, benzotriazole concentration 100ppm
After washing for 5 seconds in the acid wash with the addition of water, and then washing with water, an aqueous solution with a polyethylene glycol concentration of 30 pm, a triethanolamine concentration of 300 ppm, and a benzotriazole concentration of 50 ppm (7
It was immersed in 0 ° C.) for 5 seconds and dried.

The products subjected to the anticorrosion treatment in Examples 2 and 3 did not cause discoloration in the sulfurous acid gas test and the wet cycle test, and had a good anticorrosion effect.

Comparative Example 1 Phosphorus deoxidized copper was sequentially subjected to alkaline degreasing cleaning and acid cleaning by a conventional method. Then, the benzotriazole concentration 30
0ppm, triethanolamine concentration 300ppm aqueous solution (70
C.) for 5 seconds and dried.

The product rust-proofed by the above method did not cause discoloration in the sulfurous acid gas test and the wet cycle test,
Although the rust preventive effect was good, discoloration occurred in the material after slitting due to lack of lubricity.

Comparative Example 2 Phosphorus deoxidized copper was sequentially subjected to alkali deoxidation cleaning and acid cleaning by a conventional method. Then, the benzotriazole concentration 30
It was immersed in an aqueous solution (70 ° C.) of 0 ppm, polyethylene glycol concentration of 30 ppm, and triethanolamine concentration of 300 ppm for 5 seconds and dried.

The product rust-proofed by the above method was more likely to be discolored in the sulfur dioxide test and the wet cycle test than the product of Comparative Example 1.

Comparative Example 3 Phosphorus deoxidized copper was sequentially subjected to alkaline degreasing cleaning and acid cleaning by a conventional method. Then, the benzotriazole concentration 30
It was dipped in an aqueous solution of 0 ppm for 5 seconds, and then dipped in an emulsion solution of ethyl mercaptan concentration of 30 ppm for 5 seconds and dried.

The product subjected to anticorrosion treatment by the above-mentioned method did not cause discoloration in the sulfurous acid gas test and the wet cycle test and had a good anticorrosion effect, but because of lack of lubricity, discoloration occurred in the material after slitting. Occurred.

[0054]

As described above, according to the present invention, the anticorrosion treatment is divided into two steps, and the chelating anticorrosive coating is first applied to the material to be treated with the reaction-type main anticorrosive agent, and then the adsorption type. Treat with lubricant. Therefore, the adsorption type lubrication component
A good rust preventive effect can be obtained without inhibiting the formation of a chelate-like film formed on the copper surface by the reaction type main rust preventive agent.

Further, since the chelate-like anticorrosive film and the lubricating layer for covering and protecting the gap and the surface thereof are sequentially formed, the anticorrosive film is resistant to rubbing during cutting by a slitter and packing.

As a result, the discoloration that has occurred in the copper or copper alloy strip is reduced, and the reliability of the quality can be improved.

[Brief description of drawings]

FIG. 1 is a schematic view of an anticorrosion treatment line for explaining an example of an antirust treatment method according to the method of the present invention.

[Explanation of symbols]

 1; Copper or copper alloy sheet material 2; Acid cleaning tank 3; Water cleaning tank 4; 1st rustproof tank 5; 2nd rustproof tank 6; Draining air nozzle 7; Drying oven

Claims (3)

[Claims] 1. A method for rust-proofing a copper or copper alloy material, which comprises a component which imparts adsorption-type lubricity after treating the copper or copper alloy material with a liquid containing a reaction-type rust preventive agent. 2 of copper or copper alloy material characterized by being treated with liquid
Corrosion prevention method. 2. A liquid containing the reaction type rust preventive is a liquid containing 50 to 500 ppm of a benzotriazole derivative, and a liquid containing a component imparting lubricity of the adsorption type is a polyether nonionic surfactant. A two-stage rustproofing method for a copper or copper alloy material according to claim 1, which is a liquid containing a alkanolamine and an alkanolamine. 3. The rust preventive treatment method for a copper or copper alloy material according to claim 1, wherein the solution containing the reaction type rust preventive agent is an acid cleaning solution.