JPH0819553B2 - Copper plating method for wire material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a copper plating method for a wire material.

(Prior Art and Problems to be Solved) Copper electroplating methods are roughly classified into copper cyanide electroplating methods and copper sulfate electroplating methods from the viewpoint of industrial scale. As a copper plating method for a material, particularly a welding wire, copper cyanide electroplating, which has excellent adhesion and uniform electrodeposition, has been generally used.
However, copper sulfate electroplating is much desired as it is much less toxic than copper cyanide electroplating, has high efficiency, and is easy to treat waste liquid.

However, in copper sulfate electroplating, a substituted copper having poor adhesion is usually deposited due to a reaction of Cu ²⁺ + Fe → Cu + Fe ²⁺ when electrodeposition is performed, so that good quality plating cannot be obtained. In order to prevent the substitution copper deposition, strike plating by copper cyanide electroplating has been performed in advance.

Regarding this copper cyanide strike plating, even though the high efficiency of copper sulfate electroplating can be utilized, problems still remain unsolved in terms of toxicity and waste liquid treatment, and there is a completely different difference between copper cyanide bath and copper sulfate bath. Since two types of baths are used, it is very complicated in terms of equipment and bath management, and enlargement of equipment is inevitable.

On the other hand, as a base plating method, a method of adding allyl thiourea as a substitution inhibitor by a conventional immersion displacement plating method using copper sulfate has been proposed (Japanese Patent Publication No. 54-4329). There are drawbacks in that the adhesiveness is extremely reduced due to a slight change in the composition and the stability is poor, and in terms of waste liquid treatment, it is more difficult to treat with respect to BOD, COD regulations, etc. as compared with an additive-free bath.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and in addition to having low toxicity and high efficiency, a waste liquid treatment is simple and stable, and stable copper plating with good adhesion is obtained. It is an object of the present invention to provide a copper plating method for a wire material.

(Means for Solving the Problems) In order to achieve the above object, the present inventors have considered that other than the copper cyanide bath, in view of toxicity and various problems associated with the use of two types of plating baths. It is a bath with low toxicity and easy to treat waste liquid, and basically uses a similar electroplating bath, and performs the base plating and the subsequent copper sulfate electroplating, in which case it is highly efficient and equipment, The present invention has been made here as a result of intensive studies to find conditions that facilitate management.

That is, the copper plating method of the interface member according to the present invention, in short, CuSO against the running wire member _{4 · 5H 2 O ≧ 0.5g /} H 2 SO 4: 0.1~400g / FeSO 4 · 7H 2 O ≦ 400 g / from consisting bath composition, or more Cl to ^-: 0.01 to 100 g / a copper sulfate substitution plating liquid of the bath composition is injected from the nozzle was added after the base plating, to copper sulfate electroplating It is a feature.

 The present invention will be described in more detail below.

As described above, the present invention uses a copper sulfate plating solution having a specific composition for the base plating prior to copper sulfate electroplating (hereinafter, also simply referred to as “electroplating”),
Moreover, the essence is to adopt a method (nozzle injection method) of ejecting this copper sulfate plating solution from a nozzle instead of simply using it.

For that purpose, first, as shown below, a displacement plating bath having specific components and compositions is used.

CuSO ₄・ 5H ₂ O: When the concentration of CuSO ₄・ 5H ₂ O is less than 0.5 g /, the plating deposition rate is too slow.At economical processing speed or time, in order to prevent substitution copper deposition in the subsequent electroplating, It is not preferable because the required amount of plating cannot be obtained and the adhesion after electroplating deteriorates. Therefore, CuSO ₄ · 5H ₂ O concentration is 0.5 g /
That is all.

H ₂ SO ₄ : H ₂ SO ₄ is a component that has the effect of improving the adhesion.
However, if the concentration is less than 0.1 g /, that effect is not obtained, and the adhesiveness required for undercoating cannot be obtained. Further, if it exceeds 400 g /, the adhesion of the base plating is good, but the plating deposition rate becomes extremely slow, and the necessary amount cannot be obtained efficiently, so the adhesion after electroplating deteriorates. In order to obtain it, the number of turns must be increased, which requires excessive equipment, and requires a large amount of neutralizing agent in terms of wastewater treatment, which is uneconomical. Therefore, the concentration of H ₂ SO ₄ should be in the range of 0.1 to 400 g /.

FeSO ₄ · 7H ₂ O: FeSO ₄ · 7H ₂ O has better adhesion as the concentration is higher, but if it exceeds 400 g /, it is inappropriate for the same reason as H ₂ SO ₄ . Therefore, the concentration of FeSO ₄ · 7H ₂ O should be 400g / or less.

Cl ^-: displacement plating bath to increase the plating deposition speed the higher the bath temperature, plating time for obtaining the plated Cu amount required in the primary plating is be short, therefore, the small capacity of the plating facility Although it can be achieved, on the contrary, the adhesion becomes poor. In this respect, in the present invention, by spraying the displacement plating solution from the nozzle at a high speed, an extremely high plating deposition rate can be obtained. However, the present inventors have conducted intensive studies to find an additive whose adhesion does not decrease even if the bath temperature is raised to further increase the plating deposition rate, and whose concentration control and waste liquid treatment are easy. , Cl ^- is effective.

That is, a small amount of Cl ⁻ has the function of improving the adhesion and maintaining the high plating deposition rate obtained by raising the bath temperature. However, if too much is added, the plating deposition rate will decrease rapidly and the effect of increasing the bath temperature will be lost. Therefore, proper Cl ^- concentrations and 0.01 to 100 g / range.

Incidentally, Cl ^- NaCl as (chlorine), KCl, CaCl _2, MgC
l ₂ , HCl or the like can be used.

Next, the relationship between the displacement plating solution having the above bath composition and the subsequent electroplating solution will be described.

Although the undercoating determines whether the adhesion of the plating after electroplating is good or bad, the displacement plating solution for obtaining good undercoating is to suppress the copper sulfate concentration as described above and to obtain a relatively large amount in order to obtain a plating as dense as possible. H ₂ SO ₄ and FeSO ₄ · 7H ₂ O are included.

On the other hand, the electroplating solution only needs to contain a high concentration of copper sulfate having high electrical conductivity, since copper is only electrodeposited on the base plating which is already dense and has good adhesion.

Therefore, in order to obtain the plating with the highest efficiency and excellent adhesion, it is desirable to adjust the displacement plating solution and the electroplating solution to the following compositions, respectively. However, if it is complicated to handle two types of plating solutions, the displacement plating solution can be used as it is, although the electric power consumed by electroplating increases slightly.

Desirable displacement plating solution composition CuSO ₄ / 5H ₂ O: 0.5 to 150 g / H ₂ SO ₄ : 1 to 400 g / FeSO ₄ / 7H ₂ O: 1 to 400 g / Desirable electroplating solution composition CuSO ₄ / 5H ₂ O: 100 to 300 g / FeSO ₄ .7H ₂ O: ≦ 400 g / H ₂ SO ₄ : 10 to 300 g / The displacement plating time is appropriately determined in relation to the plating method described later. For example, when applied to the plating process of the welding wire, if the plating time is less than 0.1 seconds, it is difficult to obtain the amount of plating Cu for uniformly plating the wire material surface having a wire diameter of 0.8 to 5.5 mm to be normally plated, On the other hand, if it exceeds 10 seconds, there is no quality problem, but especially when directly connecting one or both of the front and rear processes to the plating process, the equipment length becomes too long, and the occurrence of defects when plating is stopped is not preferable. .

Next, the undercoat plating method in the present invention will be described in detail.

This undercoating method is a method in which a displacement plating solution having the above composition is sprayed from a nozzle onto a running linear material, and a linear material traveling in a space at a predetermined speed (hereinafter referred to as "wire") The displacement plating liquid, which is pressurized and supplied by a high-pressure pump, is sprayed through the nozzle at high speed and continuously, but the liquid after the substitution reaction is blown off by the high-speed jet or jet jet without staying around the wire. Moreover, the recesses on the wire surface are washed and replaced with a shockingly fresh plating solution. The effect of cleaning and replacement is very large, and plating with good adhesion is instantly completed.

FIG. 1 is an example of a displacement plating apparatus used for undercoating in the present invention, in which 1 is a wire traveling at an appropriate speed,
Reference numeral 2 is a nozzle for injecting the displacement plating solution having the above composition onto this wire, and this nozzle is one or more in the traveling direction of the traveling wire 1 and one or more in the radial direction at a predetermined angle. It is arranged. 3 through the pipe 4 as displacement plating solution 6 ejected from the nozzle 2 collide with the wire surface at 0.05 kg / cm ² or more as required impact pressure high pressure (e.g., 0.5 kg / cm ² or higher) Is a pump for supplying the displacement plating solution, and normally circulates the plating solution 6 in the lower part of the processing tank 5. Reference numeral 7 denotes a water washing or washing nozzle arranged in a water washing tank 8, which uses a pump 9 to inject water onto the wire 1 immediately after plating.

The jetting direction from the nozzle 2 can have various modes in relation to the running direction of the running wire 1, and the angle θ of the jetting direction with respect to the wire running direction can be arbitrarily determined so that 0 ° ≦ θ ≦ 180 °. (Fig. 2), when 90 ° <θ ≤ 180 °, it can be said that it is a forward direction (same direction nozzle system), and when 0 ° ≤ θ <90 °, it is a reverse direction (counterflow nozzle system). <
When θ <180 °, it can be said that the direction intersects.
In order to apply an effective impact force to the wire surface with the plating solution, a right angle direction (θ = 90 °) is preferable, and a counterflow nozzle system that sprays in the direction opposite to the wire running direction can increase the relative speed. Since it can accelerate copper precipitation,
The angle θ may be appropriately selected depending on the wire properties, the feeding method, and the like. Needless to say, in the forward direction, the injection is performed with a difference in wire traveling speed and relative speed.

In addition, one or two or more nozzles may be appropriately arranged in the wire traveling direction and one or two or more nozzles may be arranged in the wire radial direction depending on plating conditions such as a wire traveling speed and a predetermined plating thickness.

When arranging a plurality of nozzles in the wire radial direction, it is possible to select in consideration of the wire cross-sectional shape in various directions such as 2 directions and 3 directions with respect to the wire diameter. The angle δ formed by each direction is about δ = 180 ° when there are two nozzles (FIG. 3), and when there are three nozzles, about δ ₁ ,
δ ₂ , δ ₃ = 120 ° (Fig. 4) are arranged so as to form the same or substantially the same uniform angle, and as shown in Fig. 4, it is necessary to consider that the plating solution is efficiently applied to the entire surface of the wire. desirable.

Further, in relation to the wire traveling method, the case where the wire is made to travel straight is shown in the above example.
As shown in (b), in the case of a method in which a plurality of turn rollers 10 are arranged in the plating tank 5 to change the direction of the wire 1 a plurality of times, a plurality of plating solutions are sprayed on the front and back surfaces of the wire. It is possible to arrange the individual nozzles 2, and in this case, it is possible to reduce the length of the plating tank 5.

Further, as shown in FIG. 8, it is possible to cause the wire 1 to travel in a spiral shape, and to inject the plating liquid by the nozzle 2 at the apex, bottom, etc. of the spiral travel locus. It is possible to reduce the processing length in the moving direction.

The nozzle shown in the above nozzle arrangement mode is an example in which the nozzle is arranged on the outer side of the running wire, and it can be said that it is a so-called jet nozzle system. Driving method is also possible. That is, as shown in FIG. 5, the wire 1 is passed through the center of the pipe-shaped nozzle 2'and the plating solution 6 is jetted in the direction opposite to the running direction of the wire (counterflow) to increase the relative speed. In addition, it is a method that prevents the retention of iron ions and always supplies a fresh plating solution.

Further, when one or more nozzles are provided so that the jetting direction of the plating solution is the same as the wire traveling direction (forward flow), the jetting direction is the forward direction, so that there is a difference between the wire traveling speed and the relative speed. It is better to let it be sprayed. In the case of the forward nozzle arrangement of the nozzle center wire traveling method or the counterflow nozzle arrangement, the effect is smaller than that of the jet nozzle method. The reason is that the plating solution sprayed from the nozzle becomes a laminar flow that is almost parallel to the wire surface, so the plating solution has poor agitation, activation of the wire surface and ion diffusion of the plating solution are small. It is difficult to obtain the sufficient effect, but it is significantly superior to the conventional immersion plating method.

Also in the case of the nozzle center wire traveling method, as shown in FIG. 6, a pair of pipe-shaped nozzles 2 ′ are symmetrically opposed to each other in relation to the jetting direction of the plating solution and the number of nozzles, and the nozzle center A modification method is possible in which the wire 1 is run and the plating solution 6 is jetted in the intersecting direction. In this case, the plating solution is jetted at high speed from each nozzle, and becomes a complete turbulent flow (turbulent flow region 12) at the portion where the laminar flow region 11 of the counter flow (downstream nozzle) and the forward flow (upstream nozzle) collides, and the wire Instant replacement of the plating solution is achieved over the entire circumference of the surface. When the jet flows in both directions collide with each other in this manner, the impact force promotes the activation of the wire surface, while the turbulent flow generated increases the ion diffusion of the plating solution, thereby performing high-speed and efficient plating.

However, in the case of the nozzle center wire traveling method, it is necessary to provide a gap within the nozzle that allows the wire to pass smoothly, and if a gap is provided, the atmosphere is sucked from the side opposite to the side where the plating solution is blown out and air is drawn around the wire. Is more likely to intervene, the plating efficiency tends to be lower than that of the jet nozzle method, or the plating efficiency tends to decrease due to oxidation of the wire iron material and deterioration of the plating solution. As the wire runs in a narrow gap, the deposited metal copper may grow at the nozzle end and scratch the wire. Further, depending on the state of the nozzle arrangement, the sprayed plating solution reaches a long distance and becomes a mist, which causes a problem of deteriorating the environment.

Next, other points to be noted in each injection mode of the present invention will be described. First, the impact pressure of the plating solution on the wire is preferably as high as possible in order to achieve each action by the above-mentioned jetting, and a value of 0.05 kg / cm ² or more is desirable. The higher the impact pressure, the better the plating adhesion. The supply pressure and flow rate of the plating solution by the pump are determined according to the impact pressure.

As shown in FIG. 9, when spraying one wire 1 with one nozzle 2, the spray width (range) is narrowed as shown in (a). In case of spraying on a plurality of wires 1 by a single nozzle 2, it is possible to make a concentrated hit (b).
The spray width (range) may be widened as shown in (1), and in this case, the spray width can be changed depending on the shape of the outlet of the nozzle 2 as necessary.

Furthermore, the wire speed of the wire is not particularly limited, but even if the wire speed is selected in a wide range of 50 to 500 m / min, good plating can be performed within the range of the present plating bath composition, and plating equipment can be downsized. To adjust the amount of plated Cu depending on the linear velocity, select the total wire length (wire length in the plating equipment) and the effective contact length of the plating solution (sum of spray part lengths l ₁ , l ₂ ..., see Fig. 10). It is possible by

(Example) Next, the Example of this invention is shown.

Example 1 Using the apparatus shown in FIGS. 7 (a) and 7 (b), copper sulfate displacement plating solutions of various compositions shown in Table 1 were sprayed from a nozzle to perform undercoating, and then copper sulfate electroplating was performed. Then, a performance confirmation test was performed. The results are also shown in Table 1.

The pretreatment is performed by pickling with HCl, and the details of the undercoating conditions and the copper sulfate electroplating conditions are as follows.

Underplating conditions Plated wire: Mild steel wire (Wire diameter 2.6mm) Plating bath temperature: 30 ° C Injection pressure: 1kg / cm ² Plating solution injection flow rate: 450 / min Total wire length: 2m (The wire inside the equipment in Fig. 7) Length) Effective length of contact with plating solution: 0.2m (spray length l ₁ , l ₂ …, see Fig. 10) Wire traveling speed: 150m / min Copper sulfate electroplating conditions CuSO ₄ / 5H ₂ O: 250g / H ₂ SO ₄ : 50g / Bath temperature: 60 ° C Cathode current density: 50A / dm ² Linear velocity: 150m / min Total wire length: 20m For evaluation of adhesion after copper sulfate electroplating, use a sample wire. Co-wound as shown in Fig. 11,
Magnify the surface of the wound wire by 30 times to observe the plating peeling condition, and visually observe, if there is no peeling, mark ◎, if there is a trace of peeling, mark ○; if there is slight peeling, mark Δ,
The case where there was a large amount of peeling was marked with X and evaluated. The evaluation criteria are the same in the following Examples 2 and 3.

As is clear from Table 1, No. 5 to No. 12 are examples of the present invention, and the adhesion after electroplating is good. It is considered that this is because the adhesion of the undercoating is good and a sufficient film thickness is secured to prevent substitution copper deposition during electroplating.

On the other hand, Comparative Examples No. 1 to No. 4 out of the range of the present invention have poor adhesion after electroplating. This is because the adhesion of the undercoat is poor (No.2), or the adhesion of the undercoat is good but the above film thickness is not secured (No.1, No.3 to No.4). is there.

In particular, No. 5 to No. 8 and No. 10 of the present invention have very good adhesion after electroplating. This is CuSO ₄ / 5H ₂
It is considered that the O concentration is as low as less than 150 g /, and the adhesion of the undercoat is particularly good.

In addition to the above, other electroplating conditions include CuSO ₄・ 5H ₂ O: 10 to 300 g / H ₂ SO ₄ : 10 to 300 g / bath temperature: 10 to 80 ° C Cathode current density: 1 to 300 A / dm ² . It has been confirmed that the same good plating can be obtained if it exists.

The amount of plated Cu obtained after electroplating is in the range of 0.2 to 0.3% by weight based on the total weight of the wire.

Furthermore, substitution of thiourea compounds such as thiourea, allylthiourea, acetylthiourea, etc., sugar condensate, gelatin, dextrin, naphthalene disulfonic acid, glycerin, amines, amino acids, polyacrylamides, linear carboxylic acids, butynediol, etc. It has also been confirmed that good plating can be similarly obtained by adding various additives that contribute to suppression or uniform electrodeposition.

Example 2 In order to confirm the effect of adding chlorine (Cl ⁻ ) when the plating bath temperature was raised in the undercoating, the apparatus shown in FIGS. 7 (a) and 7 (b) was used and the results are shown in Table 2. The copper sulfate displacement plating solution of various compositions with various changes of the plating bath temperature and Cl ^- concentration was sprayed from the nozzle to perform the base plating, and then the copper sulfate electroplating was performed to perform the performance confirmation test. . The results are also shown in Table 2.

The pretreatment was carried out by pickling with HCl, and the undercoating conditions and copper sulfate electroplating conditions were the same as in Example 1.

As is clear from Table 2, when the Cl ^- addition amount is as low as 0.007 g / (No.1 to No.6), the higher the plating bath temperature, the lower the adhesion after electroplating tends to be. is there. It is considered that this is because the adhesiveness of the base plating was lowered.

On the other hand, if the amount of Cl ^- addition is too high at 110 g / (No. 16, N
o.17) has poor adhesion after electroplating. It is considered that this is because the adhesion of the base plating is good, but the deposition rate is rapidly reduced, and a film thickness sufficient to prevent the deposition of substitutional copper during electroplating cannot be obtained.

However, when the amount of Cl ^- addition is controlled to an appropriate range of 0.01 g / or more and 100 g / or less (No.7 to No.15),
Excellent adhesion after electroplating. This is because the adhesiveness of the base plating does not decrease even when the plating bath temperature becomes high, and the required film thickness is secured.

The amount of plated Cu obtained after electroplating is in the range of 0.2 to 0.4% by weight based on the total weight of the wire.

Example 3 In order to compare the undercoat plating according to the present invention (nozzle jet method) with the undercoat according to the normal immersion displacement plating method disclosed in the above-mentioned Japanese Patent Publication No. 54-4329, after performing each undercoat plating. , Copper sulfate electroplating was performed, and a performance confirmation test was performed. The results are shown in Table 3.

The base plating conditions and copper sulfate electroplating conditions are as follows.

Test conditions Plated wire: Mild steel wire (Wire diameter 2.6mmφ) Wire speed: 150m / min Base plating condition Bath composition: CuSO ₄ / 5H ₂ O = 50g / H ₂ SO ₄ = 100g / FeSO ₄ / 7H ₂ O = 5g However, allyl thiourea (additive) was tested with and without addition as shown in Table 3.

Bath temperature: As shown in Table 3, tests were carried out by changing to several types.

Plating time: 10 sec Plating method: In the example of the present invention, by the nozzle injection method shown in Example 1,
Further, the comparative example was tested by an ordinary dipping method.

Copper sulfate electroplating conditions Bath composition: CuSO ₄ / 5H ₂ O = 250g / H ₂ SO ₄ = 50g / FeSO ₄ / 7H ₂ O = 0g / Bath temperature: 30 ° C Cathode current density: 3A / dm ² Total wire extension: As is clear from Table 3, the adhesion of the present invention example after electroplating is superior to that of the comparative example at any undercoat bath temperature. This is because the required thickness of the undercoat plating is secured in both the present invention example and the comparative example.
It is considered that the adhesion is better in the inventive example.

The amount of plated Cu after electroplating is in the range of 0.4 to 0.5% by weight based on the total weight of the wire.

Further, in the present invention example, even with the same displacement plating, since it is a novel method different from the ordinary immersion method, it is not necessary to add a substitution inhibitor, but in addition to the above-mentioned allylthiourea, thiourea such as thiourea and acetylthiourea Urea compounds, sugar-tightness,
Various additives that contribute to the suppression of substitution of gelatin, dextrin, naphthalene disulfonic acid, glycerin, amines, amino acids, polyacrylamides, linear carboxylic acids, butynediol, etc., or the denseness, uniformity, glossiness, etc. of plating films. It was confirmed that the same effect can be obtained by adding

As is clear from the above examples, in the base plating in the present invention, the necessary plating is instantly completed,
Although it is possible to obtain a wire with excellent plating adhesion, if the plating solution stays around the wire after plating, unnecessary metal copper will grow, so in order to prevent this,
It is preferable to perform draining or washing after plating as much as possible in the process and immediately after plating in terms of time, and particularly in the case of a welding wire, plating with good adhesion can be obtained. For example, in the case of the jet nozzle method shown in FIG. 1, a cleaning tank is provided on the outlet side of the plating tank 5, and one or more similar nozzles are arranged in the tank. If the wire is washed immediately after the completion of plating by jet washing with a pressure and a flow rate suitable for the wire properties, it is possible to prevent unnecessary growth of metal copper. In the experiment, it has been confirmed that a predetermined plating adhesion can be obtained by rinsing with water within 3 seconds after spraying the final plating solution.

In addition, when experiments were conducted under the following additional conditions, it was confirmed that similar effects could be obtained in such a range.

That is, the plating solution includes chemicals, wires, industrial water,
Although various impurities from device materials and the like may be contained, it is desirable that the amount of these impurities be 5 g / or less. Chemical (CuS
O ₄ , FeSO ₄ , H ₂ SO ₄ ) are impurities such as Ni, Pb, Zn,
There are As, Mn, Ti, Se, Hg and various phosphates, nitrates, ammonium compounds, sulfates, nitrogen compounds and the like. Impurities from the wire include wire chemical components such as Mn, Si, Al,
There are surface deposits such as Ti, Cr, Ni and oils and fats. As impurities from industrial water, silicates such as Ca, Mg, Na, K, Fe, and Mn, sulfates, chlorides, carbonates, hydrogen carbonates and nitrates, and silicates, sulfates, chlorides of Al. And inorganic compounds such as nitrates, or gases such as O ₂ , CO ₂ and N ₂ . Impurities from the equipment materials include those dissolved from the equipment materials such as stainless steel, resin, and rubber.

Further, Fe ³⁺ in the plating solution is preferably 50 g / or less. If this value is exceeded, the adhesion of the plating will tend to deteriorate,
The above value may be controlled by flowing an atmosphere for preventing oxidation. The analysis method of Fe ³⁺ is according to JIS M 8853 O-phenanthroline absorptiometry.

Specific gravity of plating solution is 1.05 to 1.35 (20 ℃), viscosity is 1.30 to
3.50cp (20 ℃) and pH of 1.5 or less (20 ℃) are desirable.

Furthermore, as a wire, the tensile strength (TS) is 30-30
The same effect can be obtained by applying it to a wire of 0 kgf / mm ² or a wire with both decarburization depth and grain boundary oxidation depth of 0.50 mm or less before plating.

In addition, the spray length l (the length of the wire that the spray liquid directly hits) and the length L of the non-spray part (the length of the wire that the spray does not hit directly but the liquid is attached or immersed) are It is desirable that the relationship be satisfied. It should be noted that L + 1 can be made as long as possible due to the relationship between the plating amount and the linear velocity, but the same effect can be obtained if L + 1 ≦ 200 m.

In the above description, the case where the welding wire is mainly substituted copper plating is taken as an example, but the present invention is not limited to the substitution copper plating, and the substitution tin plating or two or more kinds of metals including both copper sulfate and tin sulfate are deposited. The same effect can be obtained in the case of doing. Needless to say, the welding wire is not limited to a solid wire and may be a flux-cored wire. Further, the welding wire is not limited to the welding wire, and a furniture spring or cardboard stopper using a bead wire or a copper coat wire may be used. Needless to say, it can be applied to wire rods for various uses such as metal fittings, and therefore various shapes (circular, strip, square, etc., wire, hoop, pipe, etc.), dimensions (0.2 to 6.4 mmφ) ), It is also applicable to the linear material. As an example of the material, JIS Z 3312
(Solid wire for mild steel and high strength steel MAG welding), 3351
(Wire for submerged arc welding for carbon steel and low alloy steel), 3316 (Steel rod and wire for TIG welding of mild steel and low alloy steel), 3317 (Mag welding solid wire for molybdenum steel and chrome molybdenum steel), JIS G 3502 (Piano wire), 3505 (mild steel wire), 3506 (hard steel wire) and the like.

(Effects of the Invention) As described in detail above, according to the present invention, a copper sulfate plating solution having a specific composition is jetted from a nozzle onto a running wire rod to perform base plating, and then copper sulfate electroplating is performed. Since it is implemented, the following advantages can be obtained.

Much less toxic than copper cyanide bath and easy to treat waste liquid.

In this undercoating, displacement plating is performed entirely and instantaneously by the high speed jet or jet pressure of the plating liquid sprayed on the running linear material, so that the adhesion is excellent and the plating of a uniform film thickness is performed in a short time. The obtained product has a higher efficiency than the copper cyanide bath and does not require a rectifier, which simplifies the equipment.

When the composition of the base plating bath is the same as that of the electroplating bath, the equipment and management are extremely simple, and even if the bath compositions are different, both are basically similar baths.
Both equipment and management are simpler than those in the copper cyanide bath.

The quality of this base plating is different from the displacement plating by the ordinary immersion method or the immersion method in which a displacement inhibitor is added, and the adhesion and the denseness of the film are good as those of the copper cyanide strike plating. Cu also in copper sulfate electroplating
The substitution reaction of ²⁺ + Fe → Cu + Fe 2 ⁺ can be prevented, and good plating with good adhesion and uniform electrodeposition can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view showing an example of a plating apparatus for carrying out a jet nozzle system which is one aspect of undercoat plating in the present invention, and FIG. 2 is a jetting direction from a nozzle and wire traveling. 3 is an explanatory view showing an angle θ formed by the direction, FIG. 3 and FIG. 4 are explanatory views showing an angle δ formed by the injection direction when the number of nozzles is two or three, and FIGS. 5 and 6 are in the present invention. Explanatory drawing showing nozzles and their arrangement for a nozzle center wire traveling system which is one aspect of undercoating, and FIGS. 7 (a) and 7 (b) show an example of nozzle arrangement in the case of wire traveling using a turn roller. In the figure, (a) is a plan view,
FIG. 8B is a side view, FIG. 8 is an explanatory view showing an example of nozzle arrangement when the wire is run in a spiral shape, FIG. 9 is a view showing an injection range from the nozzle, and FIG. FIG. 10 is a diagram for explaining the length of the spray portion, and FIG. 11 is an explanatory diagram for showing a wire winding state used for plating adhesion determination. 1 ... filament material (wire), 2 ... jet nozzle, 2 '
...... Pipe-shaped nozzle, 3,9 ...... Pump, 4 …… Pipe, 5 …… Plating bath, 6 …… Plating liquid, 7 …… Washing jet nozzle, 8 …… Washing bath, 10 …… Turn roller, 11
...... Laminar basin, 12 ... turbulent basin.

Claims (2)

[Claims] 1. A copper plating of a linear material, which comprises electroplating copper sulfate after performing a base plating by jetting a copper sulfate plating solution having the following composition from a nozzle onto a running linear material. Method. CuSO ₄・ 5H ₂ O ≧ 0.5g / H ₂ SO ₄ : 0.1 to 400g / FeSO ₄ / 7H ₂ O ≦ 400g / 2. A copper plating of a linear material, which comprises electroplating copper sulfate after performing a base plating by jetting a copper sulfate plating solution having the following composition from a nozzle onto a running linear material. Method. Serial _{CuSO 4 · 5H 2 O ≧ 0.5g} / H 2 SO 4: 0.1~400g / FeSO 4 · 7H 2 O ≦ 400g / Cl -: 0.01~100g /