JPH04246173A - Metallic material plated with cu by vapor deposition excellent in corrosion resistance and design - Google Patents

Abstract

PURPOSE:To improve the corrosion resistance of a Cu plating layer formed by vapor deposition, having pinholes and deficient in corrosion resistance by forming a specified protective film on the plating layer surface. CONSTITUTION:The single or plural coating layers contg. 1-500mg/m<2> of benzotriazole and 0.6-50mg/m<2> of synthetic resin are formed on a Cu vapor- deposition plating layer to block up the pinholes of the layer, and the corrosion resistance is enhanced.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Cu-based vapor-deposited metal material with high corrosion resistance and excellent design, which is useful as building materials, household electrical appliance parts, automobile parts, interior decorations, etc.

[0002] In the present invention, the type of metal material used as the plating material is not particularly limited, and may include general steel, stainless steel,
In addition to iron-based alloys such as high-alloy steel, Al, Ti, and various alloys thereof are included, and their shapes include plate, tubular, and
It includes various shapes such as rod-like and linear.

0003

BACKGROUND OF THE INVENTION In applications that require good design (aesthetics), such as light electrical parts and interior decorations, decorative products whose aesthetic appearance is enhanced by plating are used. Among them, Cu or Cu alloy plating (hereinafter sometimes referred to as Cu-based plating) is widely used because it has a unique beautiful metallic color, including brass plating.

[0004] Methods for performing Cu-based plating include electroplating, hot-dip plating, and vapor deposition plating, but electroplating has limitations on the alloying elements that can be electrolytically deposited using the wet method. In addition, in hot-dip plating, it is difficult to use high-melting point metals, and high heat is applied to the base metal. There is a disadvantage that the material properties deteriorate due to the addition of

[0005] On the other hand, with the vapor deposition plating method, Cu-based plating can be easily obtained without any restrictions on the types of alloying elements, and there is no need to heat the base metal material to such high temperatures, so there is no need to heat the base metal material to high temperatures, so there is no risk of deterioration of the material. It has become rapidly popular recently because it has the characteristics that the deposition rate is small and that the deposition rate can be freely controlled by adjusting the amount of heat input to the deposited metal.

[0006]

[Problem to be solved by the invention] As mentioned above, the vapor deposition plating method is an excellent Cu-based plating method, but on the other hand,
Cu-based vapor deposition plating has a problem in that pinhole defects are likely to occur, and corrosion of the base metal material is likely to occur from these defective portions.

[0007] The present invention was made in view of the above-mentioned circumstances, and its purpose is to exhibit excellent corrosion resistance even when there are some pinhole defects in the vapor-deposited plating layer. The purpose of the present invention is to provide a Cu-based vapor-deposited metal material of various types.

[0008]

[Means for Solving the Problems] The structure of the Cu-based vapor-deposited metal material according to the present invention that can solve the above-mentioned problems is such that a vapor-deposited plating layer made of Cu or a Cu alloy is formed on a base metal material, and On top of that, 1~500mg/m2
The gist is that a single or multi-layer coating layer containing benzotriazole and 0.6 to 50 g/m2 of a synthetic resin is formed.

[0009]

[Operation] The reason why the corrosion resistance of Cu-based vapor-deposited metal materials is insufficient is because of the presence of pinhole defects in the vapor-deposited plating layer, as described above. Therefore, we conducted research to establish an improvement technology that would ensure high corrosion resistance even in the presence of some pinhole defects. As a result, if a coating layer containing benzotriazole and a synthetic resin is formed on a Cu-based vapor-deposited plating layer, the progress of corrosion caused by pinhole defects can be inhibited, and a Cu-based vapor-deposited metal material exhibiting excellent corrosion resistance can be obtained. I found out that it can be done.

That is, benzotriazole has a unique action of reacting with Cu to produce a water-insoluble compound [Cu(C6H4N3)2], and this reaction not only suppresses corrosion of the Cu-based vapor-deposited plating layer itself. Instead, corrosion of the base metal is significantly suppressed by contacting the base metal through the pinhole defect.

The corrosion inhibiting effect of benzotriazole is effectively exhibited by the presence of 1 mg/m 2 or more of benzotriazole in the coating layer, as will be shown in the examples below. However, this corrosion inhibition effect is saturated at 500 mg/m2, and increasing the amount beyond that level is not only uneconomical, but also poses a risk of damaging the adhesion of the coating layer to the Cu-based vapor-deposited plating layer.
The adhesion amount of r should be suppressed to about 500 mg/m2 or less. Considering the balance between corrosion inhibiting effect and adhesion, the more preferable benzotriazole content is 0.6 to 50.
It is in the range of mg/m2.

[0012] Next, the synthetic resin has the effect of fixing the benzotriazole on the vapor-deposited plating layer to prevent its outflow or elution, and also suppressing the intrusion of oxygen and water into the plating layer to further suppress the corrosion rate. This effect reduces the amount of synthetic resin deposited in the coating layer to 0.6 g/m
It is effectively exhibited by setting the value to 2 or more. However, the above-mentioned effects of synthetic resins are saturated when the amount of adhesion is around 50 g/m2, and increasing the amount beyond that is not only wasteful, but also the adhesion of the coating decreases as the coating layer becomes thicker. Since the coating is likely to peel off during processing, the amount of synthetic resin deposited should be kept to 50 g/m2 or less. A more preferable amount of synthetic resin to be applied is in the range of 1 to 500 g/m2.

The type of synthetic resin is not particularly limited, but common examples include polyolefin resins such as polyethylene and polypropylene, acrylic resins, polyurethane resins, polyamide resins, polyester resins, etc. It is also possible to use two or more of these in combination if necessary.

As described above, the present invention is characterized in that a coating layer containing specific amounts of chromate and synthetic resin is formed on a Cu-based vapor-deposited plating layer. A method in which benzotriazole is applied on a vapor-deposited plating layer to generate a reaction product with Cu, and a synthetic resin is further applied on top of it to form a layered coating, and a blend of benzotriazole and synthetic resin is simply applied. There are methods of coating as a layer or multiple layers, and in either case, similar effects can be obtained. However, in order to effectively exert the corrosion inhibiting effect of benzotriazole on the Cu vapor-deposited plating layer, it is more preferable to first apply benzotriazole on the Cu-based vapor-deposited plating layer to form a reaction product with Cu, and then apply the benzotriazole on the Cu-based vapor-deposited plating layer. It is coated with a synthetic resin layer.

[0015] In addition to pure Cu, the Cu-based metal constituting the vapor-deposited plating layer in the present invention includes Cu, Zn, Al,
Examples include Cu-based alloys containing Sn, Ni, Pb, etc., and these can be appropriately selected and used depending on the application and purpose.

[0016] The vapor deposition plating method employed in the present invention means a vapor deposition plating method in a broad sense, and in addition to the usual vacuum vapor deposition plating method, ion plating method, CV
D method, sputtering method, etc. are also included in the category of vapor deposition plating method in the present invention.

[0017]

Examples Example 1 A vapor-deposited Cu-plated steel plate was produced under the following conditions, and after the surface of the Cu-plated layer was treated with benzotriazole, a synthetic resin was further applied thereon.

[0018] The vapor-deposited Cu-plated steel plate was produced by charging Cu into a crucible placed in a vacuum evaporation chamber and evaporating it by heating, and at the same time running a strip steel plate above the crucible. Electron beam heating was used to heat the Cu, and by controlling the output of the electron beam to keep the Cu evaporation rate constant, the amount of Cu plating deposited was adjusted to about 40 g/m2.

In the benzotriazole treatment, the amount of benzotriazole deposited was adjusted by changing the concentration of the benzotriazole aqueous solution and the distance between the rubber rolls for squeezing, and the amount of benzotriazole deposited was determined as follows. . That is, first, a benzotriazole solution having the same concentration as the treatment solution is prepared, and NaCl corresponding to 1% by weight of the amount of benzotriazole is added. This Na
The same vapor-deposited steel plate as the test material is treated using a Cl-added treatment solution to obtain a benzotriazole-treated material. After immersing this treated material in a 5% HCl aqueous solution to dissolve the treated film,
The amount of Na was determined by ICP-MS (inductively coupled plasma-mass spectrometry), and the amount of benzotriazole attached was calculated by the following formula. [Quantitative value of Na] × [Ratio of benzotriazole content to Na content in treatment liquid] (%)

As the synthetic resin, water-soluble polyethylene resin (trade name "Zaixen-N" manufactured by Seitetsu Kagaku Co., Ltd.) was used, and the amount of adhesion was adjusted by selecting the solution concentration and the bar coater size. The amount was determined from the weight difference before and after peeling off the resin coating using a coating remover.

Vapor deposition plating conditions: Base metal material...Ultra low carbon Al killed steel plate (coil) (thickness 0
．． 7mm x Width 150mm) Pre-plating treatment... Alkaline electrolytic degreasing steel plate preheating temperature...400℃ Vapor deposition chamber vacuum level...5 x 10-4 Torr Plating metal...Cu, 40g/m2 Benzotriazole treatment: Treatment liquid...Aqueous benzotriazole solution (80℃) Processing method…
Dipping → Roll squeezing → Drying at 80℃ Synthetic resin application: Treatment agent: Water-soluble polyethylene resin (same as above) Treatment method: Bar coating → Drying at 120℃

Table 1 shows the amount of benzotriazole deposited, the amount of synthetic resin deposited, and the corrosion resistance (color difference) determined by the following method for each of the obtained test materials (painted steel sheets). Furthermore, the influence of the amount of benzotriazole adhesion and the amount of resin adhesion on corrosion resistance is shown in FIG.

Corrosion resistance test (color difference evaluation): Each sample material was
The sample was left in a constant temperature and humidity chamber at 98% RH for 360 hours, and the color difference before and after the test was determined using "Σ80" manufactured by Nippon Denshoku. ○: Color difference≦3 △: 3<color difference≦5 ×: color difference>3 In addition, when the color difference is 3 or less, almost no discoloration is observed by visual observation.

[0024]

[Table 1]

As is clear from Table 1 and FIG. 1, in the examples (No. 1 to 12) in which both the benzotriazole adhesion amount and the resin adhesion amount meet the specified requirements of the present invention, the color difference is 3. Comparative examples (Nos. 13 to 29) in which either the benzotriazole adhesion amount or the resin adhesion amount is insufficient have a color difference of more than 3 and have excellent corrosion resistance. Not enough.

Comparative example (No. 3) in which either the benzotriazole adhesion amount or the resin adhesion amount exceeds the specified range
0 to 37), the effect of reducing color difference is not greater than that of the examples, but rather the disadvantages are greater due to increased cost due to increased adhesion amount and peeling of the film during subsequent processing.

Example 2 A vapor-deposited Cu-Al alloy plated steel plate was produced under the following conditions.
A benzotriazole-containing synthetic resin was applied thereon. In order to manufacture the vapor-deposited Cu-Al alloy plated steel sheet, as shown in FIG. 2, crucibles 3a and 3b are arranged side by side under a strip-shaped steel plate 2 running in a vacuum vapor deposition chamber 1, and Cu and Al are charged into each crucible. , a method was adopted in which these were heated and evaporated by an electron beam 5 irradiated from an electron gun 4 and deposited on the band-shaped steel plate 2. In the figure, 3 indicates a support roll, and 7 indicates a vacuum exhaust port.

At this time, the output of the electron gun 4 is adjusted to
By keeping the heating evaporation amount of Al and Al constant, a Cu-Al based vapor deposition plating with an Al content of about 2% and a deposition amount of about 20 g/m2 was obtained.

As the benzotriazole-containing synthetic resin, a mixture of the same water-soluble polyethylene resin used in Example 1 and an aqueous benzotriazole solution was used, and the amount of benzotriazole added, solution concentration, and bar coater were adjusted. The amount of benzotriazole and resin adhered was adjusted by changing the number of the resin.

The benzotriazole adhesion amount and resin adhesion amount were determined by peeling off the coating film in the same manner as in the above example, and measuring the amount before peeling.
The total adhesion amount was determined from the subsequent weight difference, and the benzotriazole content ratio in the benzotriazole-containing resin liquid used was added to the calculation to calculate each adhesion amount.

The vapor deposition plating conditions were the same as in the previous example, including the base metal material, plating pretreatment, steel sheet preheating temperature, and vacuum degree of the vapor deposition chamber, and the plating metal was changed to Cu-2% Al, 20 g/m2. The coating agent was a benzotriazole-containing water-soluble polyethylene resin, and after coating with a bar coat, it was dried at 120°C.

[0032] The amount of benzotriazole and synthetic resin adhered and the corrosion resistance (
Table 2 and FIG. 3 collectively show the relationship between color differences.

[0033]

[Table 2]

From Table 2 and FIG. 3, almost the same trends as those obtained from Table 1 and FIG. 1 can be confirmed. That is, whether the protective film formed on the Cu-based vapor-deposited plating layer has a two-layer structure of benzotriazole and a synthetic resin, or a single-layer structure with a mixture of these, benzotriazole It can be seen that the same corrosion resistance improvement effect can be exhibited as long as the amount of adhesion and the amount of synthetic resin adhesion satisfy the specified requirements.

[0035]

[Effects of the Invention] The present invention is constructed as described above, and by coating the Cu-based vapor-deposited plating layer, which is prone to pinhole defects, with a coating film made of benzotriazole and synthetic resin with a specified amount of adhesion. , corrosion resistance is significantly improved,
Since the excellent aesthetic appearance of the Cu-based plated metal material can be maintained for a long period of time, it is extremely useful for outer panels, various metal parts, decorative materials, etc. in particular where aesthetic appearance is required.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the influence of the amount of benzotriazole and the amount of synthetic resin adhered in the coating layer on corrosion resistance (color difference) in each test material obtained in Example 1.

FIG. 2 is a schematic explanatory diagram showing the Cu-Al vapor deposition plating method employed in Example 2.

FIG. 3 is a graph showing the influence of the amount of benzotriazole and the amount of synthetic resin adhered in the coating layer on corrosion resistance (color difference) in each test material obtained in Example 2.

[Explanation of symbols]

1 Vacuum deposition chamber 2　Strip steel plate 3a Crucible 3b Crucible 4 Electron gun 5　Electron beam 6 Support role 7 Vacuum exhaust port

Claims (1)

[Claims] Claim 1: A vapor-deposited plating layer made of Cu or a Cu alloy is formed on a base metal material, and on the vapor-deposited plating layer 1 to 5
00mg/m2 of benzotriazole and 0.6 to 50
A Cu-based vapor-deposited metal material with excellent corrosion resistance and design, characterized by being formed with a single or multiple coating layer containing a synthetic resin of g/m2.