WO2012081274A1 - Nickel plating solution and nickel plating method - Google Patents

Nickel plating solution and nickel plating method Download PDF

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Publication number
WO2012081274A1
WO2012081274A1 PCT/JP2011/065425 JP2011065425W WO2012081274A1 WO 2012081274 A1 WO2012081274 A1 WO 2012081274A1 JP 2011065425 W JP2011065425 W JP 2011065425W WO 2012081274 A1 WO2012081274 A1 WO 2012081274A1
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nickel plating
nickel
solution
plating solution
bath
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PCT/JP2011/065425
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French (fr)
Japanese (ja)
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弘樹 相川
淳 飯塚
繁則 江村
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メルテックス株式会社
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D3/00—Electroplating: Baths therefor
    • C25D3/02—Electroplating: Baths therefor from solutions
    • C25D3/12—Electroplating: Baths therefor from solutions of nickel or cobalt

Definitions

  • the present invention relates to a nickel plating solution and a nickel plating method using the nickel plating solution.
  • the present invention relates to a nickel plating solution that does not contain boric acid and carboxylic acid strong organic acid and has a solution pH in a weakly acidic to neutral range.
  • Nickel plating film is used in the field of daily necessities that require decorativeness, the field of industrial products that require functions such as rust prevention and gloss, and the field of electronic components that require functions such as conductivity and solder wettability. It is used in a wide range of fields.
  • an acidic nickel plating solution such as a watt bath or a sulfamic acid bath is mainly used.
  • boric acid has been used as a pH buffering agent for suppressing pH fluctuation in order to form a stable plating film by suppressing erosion of the object to be plated.
  • boric acid was specified as a regulated substance in the revised Water Pollution Control Law that came into effect on July 1, 2001. Therefore, a technique using organic acids has been developed as a substitute for boric acid.
  • Patent Document 1 does not contain boric acid, which is difficult to treat waste water, and has a purpose of providing a nickel plating bath that does not adversely affect the work environment.
  • a nickel plating bath to which 5 mol / L aliphatic dicarboxylic acid is added is disclosed.
  • the aliphatic dicarboxylic acid malonic acid, succinic acid, glutaric acid, and adipic acid are preferable, and the aliphatic dicarboxylic acid is preferably mixed with an aqueous nickel salt solution in advance.
  • Example 1 of Patent Document 1 a nickel plating bath having a solution pH of 4.8 containing nickel sulfate 280 g / L, nickel chloride 50 g / L, malonic acid 5.0 g / L, and nickel carbonate 2.0 g / L is prepared.
  • the object to be plated is glossy. It is described that a smooth nickel-plated film with a large thickness was obtained and there was almost no pH fluctuation of the plating bath.
  • Patent Document 2 discloses nickel chloride and / or nickel sulfate as a nickel ion source for the purpose of providing a nickel plating bath that is excellent in throwing power, does not use boron, and has a low plating cost. Is 1 g / L to 20 g / L in terms of nickel ion concentration, citric acid is 50 g / L to 300 g / L in terms of citric acid monohydrate, and the solution pH is adjusted to 6.5 to 10 with ammonia. A technique using a nickel plating bath is disclosed.
  • citric acid monohydrate is 200 g / L in water
  • nickel chloride hexahydrate is 10 g / L, 20 g / L, 40 g / L, 60 g / L, and 80 g / L. , 100 g / L, and warm to dissolve.
  • concentrated ammonia water was added while measuring the pH of the solution with a pH meter
  • a hull cell test was carried out using a nickel plating solution whose pH was adjusted to 8.0, and three points were measured with a fluorescent X-ray film thickness meter. The thickness of the plating film is measured.
  • the example of Patent Document 2 is more excellent in throwing power as compared with nickel plating using a Watt bath containing boric acid having a solution pH of 4.0.
  • the inventors of the present invention by using the following nickel plating solution, stable from long acidity to neutrality without containing not only boric acid but also carboxylic acid strong organic acid. It was conceived that nickel plating can be formed while suppressing fluctuations in solution pH between regions.
  • the nickel plating solution according to the present invention is a nickel plating solution for electroplating that includes one or more nickel salts as a source of nickel ions and a pH buffer, and the pH
  • the buffering agent is aminoalkanesulfonic acid or a derivative thereof, and the solution pH is 4.0 to 6.5.
  • the nickel salt is preferably nickel sulfate and nickel chloride, and the content of the nickel salt and aminoalkanesulfonic acid or a derivative thereof is preferably in the following range.
  • Nickel sulfate hexahydrate 120 g / L to 480 g / L
  • Nickel chloride hexahydrate 15 g / L to 70 g / L
  • Aminoalkanesulfonic acid or its derivative 30 g / L to 100 g / L
  • the nickel salt is preferably nickel sulfamate and nickel chloride, and the content of the nickel salt and aminoalkanesulfonic acid or a derivative thereof is preferably in the following range.
  • Nickel sulfamate tetrahydrate 200 g / L to 600 g / L
  • Nickel chloride hexahydrate 1g / L to 6g / L
  • Aminoalkanesulfonic acid or its derivative 30 g / L to 100 g / L
  • the aminoalkanesulfonic acid or a derivative thereof is preferably taurine.
  • the nickel plating solution according to the present invention preferably contains a stress adjusting agent.
  • the stress adjusting agent is o-sulfobenzoimide and the concentration of o-sulfobenzoimide is 0.1 g / L to 5 g / L.
  • Nickel plating method uses any of the nickel plating solutions described above, the liquid temperature is set to 40 ° C to 60 ° C, and the cathode current density is 0.05 A / dm 2 to 10 A / Electrolysis is performed at dm 2 to form a nickel plating film on the surface of the object to be plated.
  • Plating product according to the present invention The plated product according to the present invention is characterized in that a nickel plating film is formed using the nickel plating method described above.
  • the nickel plating solution according to the present invention does not contain substances regulated by the Water Pollution Control Law. Moreover, the nickel plating solution according to the present invention can stably suppress the fluctuation of the solution pH of the plating solution for a long time, and has productivity, plating appearance, and various characteristics comparable to those of the conventional nickel plating solution. A nickel plating film can be formed.
  • the nickel plating solution according to the present invention has a solution pH in a weakly acidic to neutral range and does not contain boric acid or a carboxylic acid strong organic acid. For this reason, when a nickel plating film is formed on a chip part, erosion of the ceramic part of the chip part can also be suppressed, and even a chip part having a protective coating layer made of ceramics can be directly plated with nickel. Is possible.
  • the nickel plating method according to the present invention does not require operation with a reduced current density, as compared with the conventional nickel plating method. Therefore, the productivity of the plating film is also improved. Therefore, the nickel plating method using the nickel plating solution according to the present invention is suitable for nickel plating on all objects to be plated that are uneasy about corrosion resistance in addition to chip parts.
  • the nickel plating solution according to the present invention is a nickel plating solution for electroplating containing one or more nickel salts that are nickel ion supply sources and a pH buffer,
  • the pH buffering agent is aminoalkanesulfonic acid or a derivative thereof, and the solution pH is 4.0 to 6.5.
  • aminoalkanesulfonic acid or a derivative thereof is used as a pH buffer.
  • Aminoalkanesulfonic acid and its derivatives are aminosulfonic acids having a cation center and an anion center in the molecule, and are compounds that exist in a zwitterionic state in a neutral solution pH range.
  • the zwitterion becomes an anion when the contained solution becomes acidic, and becomes a cation when the solution becomes alkaline, thereby exhibiting an effect of buffering the pH of the solution containing itself.
  • the content of “aminoalkanesulfonic acid or a derivative thereof” as a pH buffer in the nickel plating solution according to the present invention will be described first.
  • the content of aminoalkanesulfonic acid or a derivative thereof is preferably 30 g / L to 100 g / L. If the content of aminoalkanesulfonic acid or a derivative thereof is less than 30 g / L, setting the solution pH of the nickel plating solution to around 6.0 is not preferable because the pH buffering effect may not be sufficiently exhibited.
  • aminoalkanesulfonic acid or a derivative thereof is contained in excess of 100 g / L, the buffering effect of the solution pH has already reached saturation, and no further effect is observed, which is a waste of resources. Absent. From the above, the content of “aminoalkanesulfonic acid or a derivative thereof” as a pH buffer is determined.
  • taurine among the “aminoalkanesulfonic acids or derivatives thereof” for the nickel plating solution according to the present invention.
  • This taurine has excellent stability in nickel plating solution among “aminoalkanesulfonic acid or its derivatives”, has excellent ability to stabilize solution quality over a long period of time, and has little change in solution pH during plating operation. It is an additive suitable for obtaining a good nickel plating film.
  • taurine is used as an orally administered drug for the human body, has no toxicity, has an advantage of being a compound that is easy to procure on the market and does not increase the load of wastewater treatment.
  • the nickel salt used as a nickel ion supply source is not particularly limited, and the nickel plating film formed by electroplating is nickel sulfamate so that the required characteristics can be satisfied. Selected from nickel chloride, nickel sulfate, nickel acetate and the like, and can be used alone or in combination.
  • the nickel plating solution according to the present invention preferably has a solution pH of 4.0 to 6.5. If the solution pH of the nickel plating solution is in a strong acid region of less than 4.0, ceramics may be eroded, which is not preferable because it cannot be used for chip component plating. On the other hand, if the solution pH of the nickel plating solution exceeds 6.5 and becomes alkaline, nickel hydroxide may be generated, and it is difficult to obtain a nickel plating solution having excellent solution stability, which is not preferable.
  • the nickel plating solution according to the present invention contains aminoalkanesulfonic acid or a derivative thereof as a pH buffer, and “a nickel salt containing nickel sulfate and nickel chloride.
  • the watt bath type nickel plating solution containing "and the" sulfamic acid bath type nickel plating solution containing nickel sulfamate and nickel chloride as nickel salts ".
  • each nickel plating solution will be described in detail.
  • the content of “aminoalkanesulfonic acid or a derivative thereof” as a pH buffering agent the above concept can be applied to any nickel plating solution.
  • the Watt bath type nickel plating solution contains 120 g / L to 480 g / L of nickel sulfate hexahydrate and 15 g / L to 70 g / L of nickel chloride hexahydrate. Is preferred. Use as a watt bath-type nickel plating solution within this range is preferable from the viewpoints of current efficiency, film properties, solution stability for long-term storage, sludge is not easily generated, and the like. As far as the blending balance of nickel sulfate hexahydrate and nickel chloride hexahydrate is concerned, there is no particular problem within the above range. The reason why the contents of nickel sulfate hexahydrate and nickel chloride hexahydrate are limited will be described below.
  • nickel chloride hexahydrate is used to ensure an appropriate nickel concentration as the plating solution. This increases the content ratio of chlorine ion and excessively increases the chlorine ion concentration. This is not preferable because a tendency to obtain a brittle nickel plating film having high internal stress and large lattice distortion is not preferable.
  • nickel sulfate hexahydrate exceeds 480 g / L, nickel hydroxide is likely to be precipitated at a solution pH of around 6.5, so that the solution stability is lacking, which is not preferable.
  • nickel chloride hexahydrate When the nickel chloride hexahydrate is less than 15 g / L in the watt bath type nickel plating solution, the function as a depolarizer cannot be exhibited, and gas is generated from the anode during the plating operation. This is not preferable because the pH of the solution becomes remarkable. On the other hand, when nickel chloride hexahydrate exceeds 70 g / L, the chlorine ion concentration becomes excessive, the internal stress is high, and the tendency to obtain a brittle nickel plating film having a large lattice strain is unfavorably increased.
  • Nickel plating solution of sulfamic acid bath system is 200g / L to 600g / L for nickel sulfamate tetrahydrate and 1g / L to 6g / L for nickel chloride hexahydrate. It is preferable to contain. In the case of a sulfamic acid bath-based nickel plating solution within this range, current efficiency, film properties, solution stability against long-term storage, and sludge are not easily generated, as with the above-described watt bath-based nickel plating solution. From the viewpoint of the above.
  • nickel chloride hexahydrate When the content of nickel chloride hexahydrate is less than 1 g / L in a sulfamic acid bath-based nickel plating solution, it cannot function as a depolarizer, and gas is generated from the anode during the plating operation. However, it is not preferable because a change in solution pH is observed. On the other hand, when the nickel chloride hexahydrate exceeds 6 g / L, the chlorine ion concentration becomes excessive, the internal stress is high, and the tendency to obtain a brittle nickel plating film having a large lattice distortion is undesirable. .
  • a plating film obtained by the electrolytic plating method has an internal stress in the lattice of the precipitated crystal.
  • internal strain is generated inside the precipitated crystal, and as a result, internal stress is generated.
  • This internal stress is influenced by the components of the plating solution, the solution temperature, the electrolysis conditions, etc., and becomes tensile stress or compressive stress.
  • the nickel plating film preferably has an internal stress in the range of stress-free to compressive stress.
  • a stress adjusting agent to the nickel plating solution according to the present invention.
  • This stress modifier is said to be included in the nickel plating film that is adsorbed on the cathode surface and deposited by electrolysis.
  • a stress adjusting agent it is said that the tensile stress of the nickel plating film tends to increase. Therefore, it is preferable to improve the adhesion between the nickel plating film and the object to be plated by adding a stress adjusting agent to the Watt bath nickel plating solution to adjust the internal stress of the nickel plating film to be formed.
  • a sulfur-containing organic compound such as o-sulfobenzoimide, paratoluenesulfamide, benzenesulfonic acid or naphthalenetrisulfonic acid can be used.
  • o-sulfobenzoic imide it is preferable to use as the stress adjusting agent. This is because o-sulfobenzoimide is easily obtained as a sodium salt among the above-mentioned sulfur-containing organic compounds, has good solubility in water, and has the greatest stress adjustment effect.
  • o-sulfobenzoic imide is added in a nickel plating solution so as to be in a concentration range of 0.1 g / L to 5 g / L.
  • concentration of this o-sulfobenzoimide is less than 0.1 g / L, it is not preferable because the amount of adsorption to the cathode is small and the effect as a stress adjusting agent cannot be exhibited.
  • concentration of o-sulfobenzoimide exceeds 5 g / L, the compressive stress contained in the nickel plating film gradually increases, but improves the adhesion between the nickel plating film and the object to be plated. The effect saturates and does not improve.
  • the “watt bath type nickel plating solution” and the “sulfamic acid bath type nickel plating solution” The range of the appropriate amount of stress modifier is different. That is, in the case of a watt bath type nickel plating solution, the concentration of the stress adjusting agent is preferably in the range of 1 g / L to 5 g / L. In the case of a sulfamic acid bath type nickel plating solution, the concentration of the stress adjusting agent is more preferably 0.1 g / L to 5 g / L.
  • Nickel Plating Form According to the Present Invention: In the nickel plating method according to the present invention, any of the above-described nickel plating solutions is used, the solution temperature is set to 40 ° C. to 60 ° C., and the cathode current density is 0.05 A / dm 2 to 10 A / Electrolysis is performed at dm 2 to form a nickel plating film on the surface of the object to be plated. In this nickel plating method, electrolysis at a higher current density is possible with a sulfamic acid bath-based nickel plating solution than with a Watt bath-based nickel plating solution.
  • the watt bath type nickel plating solution is electrolyzed at a cathode current density of 0.05 A / dm 2 to 5 A / dm 2 at a liquid temperature of 40 ° C. to 60 ° C.
  • the nickel plating solution according to the present invention does not select the type of the object to be plated. Therefore, in the field of various electric nickel plating such as decorative nickel plating applied to automobile parts, nickel plating for forming resistance circuits on conductors of printed wiring boards, and nickel plating applied to chip parts which are electronic parts. Can be used. Therefore, the nickel-plated product according to the present invention means all products in which a nickel plating film is formed using the nickel plating solution and the nickel plating method according to the present invention described above.
  • the nickel plating solution according to the present invention has a feature that the solution pH is in a neutral region of 4.0 to 6.5. Therefore, the surface is hardly damaged regardless of the material of the surface of the object to be plated.
  • the nickel plating solution according to the present invention is preferably used for an electronic component including a ceramic material that is easily damaged in the case of a strongly acidic or strongly alkaline plating solution. That is, when plating is applied to chip parts that are susceptible to damage in the case of strong acids or strong alkalis in the field of electronic parts, there is little damage to the ceramic and its protective coating layer, and a good nickel plating film on the conductive part Can be formed.
  • the nickel plating solution was evaluated based on “change in solution pH before and after electrolysis” and “characteristics of the nickel plating film obtained by electroplating”. Specifically, the stress, hardness, pinhole and uniform electrodeposition of the obtained nickel plating film were evaluated. At this time, the film stress was measured with a spiral stress meter manufactured by Yamamoto Metal Testing Co., Ltd., and the film hardness was measured with a micro hardness meter (model: MVK-E) manufactured by Akashi Seisakusho.
  • the pinhole is subjected to a ferroxyl test on a nickel plating film having an area of 5 cm ⁇ 5 cm, converted to an area of 1 cm ⁇ 1 cm, and the uniform electrodeposition is determined by a Haring cell manufactured by Yamamoto Kakin Tester Co., Ltd. evaluated. Further, the surface of the nickel plating film was observed using a scanning electron microscope (hereinafter referred to as “SEM”) at a tilt angle of 0 ° and a magnification of 10,000 times.
  • SEM scanning electron microscope
  • Example 1 a Watt-based nickel plating solution (TW1 bath) was prepared.
  • This watt bath type nickel plating solution (TW1 bath) is nickel salt, nickel sulfate hexahydrate concentration of 240 g / L, nickel chloride hexahydrate concentration of 45 g / L, taurine as pH buffering agent. The concentration is 60 g / L, and the solution pH is 4.50 using sulfuric acid or sodium hydroxide solution. Accordingly, the TW1 bath is a watt bath-based nickel plating solution that does not contain a stress modifier.
  • the composition of the TW1 bath is shown in Table 1 together with the compositions of the nickel plating solutions prepared in other examples and comparative examples.
  • Nickel Plating Film Electrolysis was carried out at a cathode current density of 5 A / cm 2 for 10 minutes using a TW1 bath with a liquid temperature of 45 ° C., a metal nickel plate as the anode and a copper hull cell plate as the cathode. A nickel plating film having a thickness of 2 ⁇ m was formed. The solution pH of the TW1 bath after electrolysis for 10 minutes was 4.52. The obtained nickel plating film had a stress of 119 Pa, a hardness of Hv221, a pinhole of 3.3 holes / cm 2 , and a uniform electrodeposition of 3.5% for 1: 3 and 5.2 for 1: 5. %Met.
  • Example 2 the TW1 bath prepared in Example 1 further contains 1 g / L of a sodium salt of o-sulfobenzoimide as a stress adjusting agent, and a Watt bath having a solution pH of 4.50. It was prepared as a nickel plating solution (TW2 bath).
  • the composition of the TW2 bath is shown in Table 1 together with the compositions of the nickel plating solutions prepared in other examples and comparative examples.
  • Example 3 sodium naphthalene trisulfonate was added in place of the sodium salt of o-sulfobenzoimide used as a stress modifier in the TW2 bath prepared in Example 2, and the solution pH was 4.
  • TW3 bath nickel plating solution
  • the composition of the TW3 bath is shown in Table 1 together with the compositions of the nickel plating solutions prepared in other examples and comparative examples.
  • nickel plating solution Preparation of nickel plating solution:
  • nickel sulfamate tetrahydrate is 450 g / L as nickel salt
  • nickel chloride hexahydrate is 3 g / L
  • taurine as pH buffer
  • solution pH 4 .50 sulfamic acid bath nickel plating solution (TS4 bath) is a nickel plating solution of a sulfamic acid bath system that does not contain a stress adjusting agent.
  • the solution pH was adjusted using a sulfamic acid solution or a sodium hydroxide solution.
  • the composition of the TS4 bath is shown in Table 1 together with the compositions of the nickel plating solutions prepared in other examples and comparative examples.
  • TS4 bath evaluated the erosion property of chip parts. Evaluation was performed using a chip part varistor and a low-temperature co-fired ceramic (hereinafter referred to as “LTCC”), and the amount of erosion by immersion in a TS4 bath was evaluated.
  • LTCC low-temperature co-fired ceramic
  • the erosion amount of the chip parts was measured by mass change before and after being immersed in a 45 ° C. TS4 bath for 5 hours. Specifically, about 10 g of a varistor having been weighed and LTCC were separately immersed for 5 hours in a stirring TS4 bath with a liquid volume of 100 ml. After 5 hours, the entire amount of each chip part was pulled up from the TS4 bath, washed with water, drained with a paper towel, and dried at 60 ° C. for 30 minutes using a circulation oven. As a result of measuring the mass of the dried chip part, the mass reduction rate of the varistor was 0.9%, and the mass reduction rate of LTCC was 0.1% or less.
  • the erosion amount of the chip component is shown in Table 2 together with the evaluation result in Comparative Example 4.
  • Example 5 the sulfamic acid bath having a solution pH of 4.50 containing 1 g / L of sodium salt of o-sulfobenzoimide as a stress adjusting agent with respect to the TS4 bath prepared in Example 4.
  • a nickel plating solution (TS5 bath) was prepared.
  • the composition of the TS5 bath is shown in Table 1 together with the compositions of the nickel plating solutions prepared in other examples and comparative examples.
  • CW1 bath is a conventional Watt bath type nickel plating solution that does not contain a stress modifier.
  • the composition of the CW1 bath is shown in Table 1 together with the compositions of the nickel plating solutions prepared in the examples and other comparative examples.
  • the Watt bath system having a solution pH of 4.50 containing 1 g / L of sodium salt of o-sulfobenzoimide as a stress adjusting agent with respect to the CW1 bath prepared in Comparative Example 1.
  • a nickel plating solution (CW2 bath) was prepared.
  • the composition of the CW2 bath is shown in Table 1 together with the compositions of the nickel plating solutions prepared in the examples and other comparative examples.
  • Example 2 Electrolysis was performed in the same manner as in Example 1 using a CW2 bath to form a nickel plating film having a thickness of 2 ⁇ m.
  • the solution pH of the CW2 bath after electrolysis for 10 minutes was 4.55.
  • the stress, hardness, pinhole and uniform electrodeposition of the obtained nickel plating film were measured in the same manner as in Example 1.
  • the stress was ⁇ 92 Pa
  • the hardness was Hv 453
  • the pinholes were 2.4 holes / cm 2
  • the throwing power was 4.4% for 1: 3 and 7.1% for 1: 5.
  • Table 2 shows the evaluation results of the solution pH and nickel plating film characteristics of the CW2 bath after electrolysis.
  • the surface of the nickel plating film was observed by SEM in the same manner as in Example 1. This SEM observation image is shown in FIG. 2B together with the SEM observation image of the nickel plating film surface obtained in Example 2.
  • Example 2 Electrolysis was carried out in the same manner as in Example 1 using a CW3 bath to form a nickel plating film having a thickness of 2 ⁇ m.
  • the solution pH of the CW3 bath after electrolysis for 10 minutes was 4.55.
  • the stress, hardness, pinhole and uniform electrodeposition of the obtained nickel plating film were measured in the same manner as in Example 1.
  • the stress was 110 Pa
  • the hardness was Hv455
  • the pinhole was 2.7 pieces / cm 2
  • the uniform electrodeposition was 3.8% for 1: 3 and 6.2% for 1: 5.
  • Table 2 shows the evaluation results of the solution pH and nickel plating film characteristics of the CW3 bath after electrolysis.
  • the surface of the nickel plating film was observed by SEM in the same manner as in Example 1. This SEM observation image is shown in FIG. 3B together with the SEM observation image of the nickel plating film surface obtained in Example 3.
  • Example 4 Evaluation of erosion property: In the same manner as in Example 4, the erosion property of the chip component by the TS4 bath was evaluated. As a result, the mass reduction rate of the varistor was 6.6%, and the mass reduction rate of LTCC was 0.2%. Table 2 shows the amount of erosion of the chip parts together with the evaluation results in Example 4.
  • Example 2 Electrolysis was performed in the same manner as in Example 1 using a CS5 bath to form a nickel plating film having a thickness of 2 ⁇ m.
  • the solution pH of the CS5 bath after electrolysis for 10 minutes was 4.54.
  • the stress, hardness, pinhole and uniform electrodeposition of the obtained nickel plating film were measured in the same manner as in Example 1.
  • the stress was 99.2 Pa
  • the hardness was Hv 432
  • the pinhole was 0.9 pieces / cm 2
  • the throwing power was 2.9% for 1: 3 and 3.2% for 1: 5.
  • Table 2 shows the evaluation results of the solution pH and nickel plating film characteristics of the CW5 bath after electrolysis.
  • the surface of the nickel plating film was observed by SEM in the same manner as in Example 1. This SEM observation image is shown in FIG. 5B together with the SEM observation image of the nickel plating film surface obtained in Example 5.
  • ⁇ Contrast between Example and Comparative Example 1 Change in pH of solution before and after electrolysis> As shown in Table 2, the solution pH of the nickel plating solution after electrolysis increased by 0.02 to 0.03 in the examples, and increased by 0.04 to 0.07 in the comparative examples. Further, when the degree of increase in the solution pH is compared between similar bath compositions, the comparative example is 0.01 to 0.05 higher than the example. Therefore, a nickel plating solution containing aminoalkanesulfonic acid or a derivative thereof as a pH buffering agent has a smaller change in solution pH when the same electrolysis conditions are employed than when a conventional nickel plating solution is used. That is, it can be determined that the nickel plating solution containing aminoalkanesulfonic acid or a derivative thereof as a pH buffer is a nickel plating solution capable of stable nickel plating over a long period of time.
  • FIG. 1 to FIG. 5 the SEM photograph (a) of the nickel plating film surface obtained in the example and the SEM photograph (b) of the nickel plating film surface obtained in the comparative example are compared. From FIG. 1 to FIG. 5, there is no significant difference in appearance between when taurine is used as a pH buffering agent and when boric acid is used. In addition, as shown in Table 2, there is no significant difference in film characteristics and throwing power. On the other hand, the film characteristics are greatly influenced by the stress modifier in both the Watt bath system and the sulfamic acid bath system. Therefore, even when aminoalkanesulfonic acid or a derivative thereof is used instead of boric acid as a pH buffer, a nickel plating film having the same film characteristics as when a conventional nickel plating solution is used can be obtained. I can judge.
  • the nickel plating solution of the embodiment containing aminoalkanesulfonic acid or a derivative thereof as a pH buffer is boron-free and at the same time, It can be determined that the nickel plating solution exhibits a great effect in preventing erosion.
  • the nickel plating solution according to the present invention does not contain substances regulated by the Water Pollution Control Law. Therefore, it is a plating solution with very little environmental load / drainage load.
  • the nickel plating solution according to the present invention can be used for a long period of time and has excellent cost performance because it can stably suppress fluctuations in the pH of the plating solution for a long time.
  • This nickel plating solution can be used in all technical fields that require nickel plating. And since the nickel plating liquid which concerns on this invention is a solution pH from weakly acidic to neutral area
  • the nickel plating method according to the present invention can be carried out using existing existing equipment and does not require new equipment investment, so that the existing equipment can be used effectively.

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Abstract

The purpose of the present invention is to provide: a nickel plating solution that does not use boric acid or carboxylic acid, has a pH in the range of low to medium acidity, and retains conventional productivity; and a nickel plating method that uses said nickel plating solution. In order to achieve said purpose, a nickel plating solution for electric plating is used that: includes a pH buffering agent and one or more types of nickel salts which are a supply source for nickel ions; and is characterized by the pH buffering agent being an amino alkane sulfonic acid or a derivative thereof and by having a pH of 4.0-6.5.

Description

ニッケルめっき液及びニッケルめっき方法Nickel plating solution and nickel plating method
　本件発明は、ニッケルめっき液、及びそのニッケルめっき液を用いたニッケルめっき方法に関する。特に、ホウ酸とカルボン酸系強有機酸とを含まず、弱酸性から中性領域の溶液ｐＨを有するニッケルめっき液に関する。 The present invention relates to a nickel plating solution and a nickel plating method using the nickel plating solution. In particular, the present invention relates to a nickel plating solution that does not contain boric acid and carboxylic acid strong organic acid and has a solution pH in a weakly acidic to neutral range.
　ニッケルめっき皮膜は、装飾性を要求される日用品の分野、さび防止や光沢性の機能を要求される工業製品の分野や、導電性や半田濡れ性などの機能を要求される電子部品の分野など、広い分野で活用されている。 Nickel plating film is used in the field of daily necessities that require decorativeness, the field of industrial products that require functions such as rust prevention and gloss, and the field of electronic components that require functions such as conductivity and solder wettability. It is used in a wide range of fields.
　このニッケルめっき皮膜の形成には、主にワット浴やスルファミン酸浴等の酸性ニッケルめっき液が用いられている。ここで、当該酸性ニッケルめっき液は、被めっき物の浸食を抑制して安定しためっき皮膜を形成すべく、ｐＨ変動を抑制するためのｐＨ緩衝剤としてホウ酸が用いられてきた。ところが、ホウ酸は、２００１年７月１日施行の改正水質汚濁防止法において規制対象物質とされた。そのため、ホウ酸の代替物質として、有機酸類を用いる技術が開発されている。 For the formation of the nickel plating film, an acidic nickel plating solution such as a watt bath or a sulfamic acid bath is mainly used. Here, in the acidic nickel plating solution, boric acid has been used as a pH buffering agent for suppressing pH fluctuation in order to form a stable plating film by suppressing erosion of the object to be plated. However, boric acid was specified as a regulated substance in the revised Water Pollution Control Law that came into effect on July 1, 2001. Therefore, a technique using organic acids has been developed as a substitute for boric acid.
　例えば、特許文献１には、排水処理が困難なホウ酸を含まず、作業環境に悪影響を及ぼさないニッケルめっき浴を提供することを目的として、ホウ酸の代わりに０．０１ｍｏｌ／Ｌ～０．５ｍｏｌ／Ｌの脂肪族ジカルボン酸を添加したニッケルめっき浴が開示されている。そして、脂肪族ジカルボン酸としては、マロン酸、コハク酸、グルタル酸、アジピン酸が好ましく、脂肪族ジカルボン酸は、予めニッケル塩水溶液と混合しておくことが好ましいとしている。 For example, Patent Document 1 does not contain boric acid, which is difficult to treat waste water, and has a purpose of providing a nickel plating bath that does not adversely affect the work environment. A nickel plating bath to which 5 mol / L aliphatic dicarboxylic acid is added is disclosed. As the aliphatic dicarboxylic acid, malonic acid, succinic acid, glutaric acid, and adipic acid are preferable, and the aliphatic dicarboxylic acid is preferably mixed with an aqueous nickel salt solution in advance.
　この特許文献１の実施例１では、硫酸ニッケル２８０ｇ／Ｌ、塩化ニッケル５０ｇ／Ｌ、マロン酸５．０ｇ／Ｌと、炭酸ニッケル２．０ｇ／Ｌを含む溶液ｐＨ４．８のニッケルめっき浴を調製し、これに被めっき物として７０×１００ｍｍの真鍮板を陰極とし、陽極にニッケル板を用いるハルセル槽で温度５０℃、電流２Ａで１０分間ニッケルめっきを行った結果、被めっき物には、光沢のある平滑なニッケルめっき皮膜が得られ、めっき浴のｐＨ変動もほとんどなかったと記載されている。 In Example 1 of Patent Document 1, a nickel plating bath having a solution pH of 4.8 containing nickel sulfate 280 g / L, nickel chloride 50 g / L, malonic acid 5.0 g / L, and nickel carbonate 2.0 g / L is prepared. In addition, as a result of performing nickel plating for 10 minutes at a temperature of 50 ° C. and a current of 2 A in a hull cell tank using a 70 × 100 mm brass plate as the cathode and a nickel plate as the anode, the object to be plated is glossy. It is described that a smooth nickel-plated film with a large thickness was obtained and there was almost no pH fluctuation of the plating bath.
　また、特許文献２には、均一電着性に優れ、ホウ素を用いることがなく、めっきコストも低廉なニッケルめっき浴を提供することを目的として、ニッケルイオン源としての塩化ニッケル及び／又は硫酸ニッケルをニッケルイオン濃度換算で１ｇ／Ｌ～２０ｇ／Ｌ含み、クエン酸をクエン酸・１水和物換算で５０ｇ／Ｌ～３００ｇ／Ｌ含み、溶液ｐＨがアンモニアによって６．５～１０に調節されていることを特徴とするニッケルめっき浴を用いる技術が開示されている。 Patent Document 2 discloses nickel chloride and / or nickel sulfate as a nickel ion source for the purpose of providing a nickel plating bath that is excellent in throwing power, does not use boron, and has a low plating cost. Is 1 g / L to 20 g / L in terms of nickel ion concentration, citric acid is 50 g / L to 300 g / L in terms of citric acid monohydrate, and the solution pH is adjusted to 6.5 to 10 with ammonia. A technique using a nickel plating bath is disclosed.
　この特許文献２の実施例では、水にクエン酸・１水和物を２００ｇ／Ｌ、塩化ニッケル・６水和物を１０ｇ／Ｌ、２０ｇ／Ｌ、４０ｇ／Ｌ、６０ｇ／Ｌ、８０ｇ／Ｌ、１００ｇ／Ｌ、のそれぞれの量を添加して加温溶解し、放冷する。その後、ｐＨメータで溶液ｐＨを測定しながら濃アンモニア水を加え、溶液ｐＨを８．０となるように調節したニッケルめっき液を用いてハルセル試験を実施し、蛍光Ｘ線膜厚計によって３箇所のめっき皮膜の膜厚を測定している。その結果、特許文献２の実施例の方が、溶液ｐＨ４．０のホウ酸を含むワット浴を用いたニッケルめっきに比べ、均一電着性に優れていると記載している。 In Examples of Patent Document 2, citric acid monohydrate is 200 g / L in water, nickel chloride hexahydrate is 10 g / L, 20 g / L, 40 g / L, 60 g / L, and 80 g / L. , 100 g / L, and warm to dissolve. Then, concentrated ammonia water was added while measuring the pH of the solution with a pH meter, a hull cell test was carried out using a nickel plating solution whose pH was adjusted to 8.0, and three points were measured with a fluorescent X-ray film thickness meter. The thickness of the plating film is measured. As a result, it is described that the example of Patent Document 2 is more excellent in throwing power as compared with nickel plating using a Watt bath containing boric acid having a solution pH of 4.0.
特開２００１－１０７２８４号公報JP 2001-107284 A 特開２００９－６２５７７号公報JP 2009-62577 A
　しかし、市場では、特許文献１及び特許文献２に開示されているようなマロン酸、クエン酸等のカルボン酸系強有機酸を含むニッケルめっき液は、得られるめっき皮膜の品質バラツキが大きいと言われている。即ち、特許文献１及び特許文献２が開示するニッケルめっき液のように、ｐＨ緩衝剤としてマロン酸やクエン酸等のカルボン酸系強有機酸を含有させたとしても、長時間安定してめっき液のｐＨの変動を抑制することができず、結果として安定しためっき皮膜を形成することが困難となっていた。 However, in the market, nickel plating solutions containing carboxylic acid-based strong organic acids such as malonic acid and citric acid as disclosed in Patent Document 1 and Patent Document 2 are said to have large variations in the quality of the resulting plating film. It has been broken. That is, like the nickel plating solutions disclosed in Patent Document 1 and Patent Document 2, even if a carboxylic acid strong organic acid such as malonic acid or citric acid is contained as a pH buffer, the plating solution is stable for a long time. Thus, it has been difficult to form a stable plating film.
　一方では、特許文献１及び特許文献２に開示されているようなカルボン酸系強有機酸を含むニッケルめっき液の場合には、調製したニッケルめっき液の溶液ｐＨによっては、被めっき物、特にセラミックス素材の場合には、その表面を浸食して損傷を発生させる場合もあった。 On the other hand, in the case of a nickel plating solution containing a carboxylic acid strong organic acid as disclosed in Patent Document 1 and Patent Document 2, depending on the solution pH of the prepared nickel plating solution, an object to be plated, particularly ceramics In the case of a material, the surface sometimes eroded and sometimes caused damage.
　以上のことから、市場では、長時間安定してめっき液の溶液ｐＨの変動を抑制することが可能で、従来通りの生産性と、従来と同等の外観や特性を備えたニッケルめっき皮膜が得られ、且つ、水質汚濁防止法での規制物質を含まないニッケルめっき液、及び、そのニッケルめっき液を用いたニッケルめっき方法が求められていた。 From the above, it is possible to suppress the fluctuation of the plating solution pH stably for a long time in the market, and it is possible to obtain a nickel plating film with the same productivity and the same appearance and characteristics as before. In addition, there has been a demand for a nickel plating solution that does not contain a regulated substance in the Water Pollution Control Law and a nickel plating method using the nickel plating solution.
　そこで、鋭意研究の結果、本件発明者等は、以下のニッケルめっき液を用いることにより、ホウ酸のみならずカルボン酸系強有機酸を含有することなく、長時間安定して弱酸性から中性領域の間で溶液ｐＨの変動を抑制した状態でニッケルめっきの形成が可能になることに想到した。 Therefore, as a result of earnest research, the inventors of the present invention, by using the following nickel plating solution, stable from long acidity to neutrality without containing not only boric acid but also carboxylic acid strong organic acid. It was conceived that nickel plating can be formed while suppressing fluctuations in solution pH between regions.
本件発明に係るニッケルめっき液：　本件発明に係るニッケルめっき液は、ニッケルイオンの供給源である１種以上のニッケル塩とｐＨ緩衝剤とを含む電気めっき用のニッケルめっき液であって、当該ｐＨ緩衝剤がアミノアルカンスルホン酸又はその誘導体であり、且つ、溶液ｐＨが４．０～６．５であることを特徴としている。 Nickel plating solution according to the present invention: The nickel plating solution according to the present invention is a nickel plating solution for electroplating that includes one or more nickel salts as a source of nickel ions and a pH buffer, and the pH The buffering agent is aminoalkanesulfonic acid or a derivative thereof, and the solution pH is 4.0 to 6.5.
　そして、本件発明に係るニッケルめっき液は、前記ニッケル塩が硫酸ニッケルと塩化ニッケルであり、当該ニッケル塩とアミノアルカンスルホン酸又はその誘導体の含有量が以下に示す範囲であることが好ましい。 In the nickel plating solution according to the present invention, the nickel salt is preferably nickel sulfate and nickel chloride, and the content of the nickel salt and aminoalkanesulfonic acid or a derivative thereof is preferably in the following range.
　硫酸ニッケル・６水和物　　　　　　　　　：　１２０ｇ／Ｌ～４８０ｇ／Ｌ
　塩化ニッケル・６水和物　　　　　　　　　：　１５ｇ／Ｌ～７０ｇ／Ｌ
　アミノアルカンスルホン酸又はその誘導体　：　３０ｇ／Ｌ～１００ｇ／Ｌ Nickel sulfate hexahydrate: 120 g / L to 480 g / L
Nickel chloride hexahydrate: 15 g / L to 70 g / L
Aminoalkanesulfonic acid or its derivative: 30 g / L to 100 g / L
　また、本件発明に係るニッケルめっき液は、前記ニッケル塩がスルファミン酸ニッケルと塩化ニッケルであり、当該ニッケル塩とアミノアルカンスルホン酸又はその誘導体の含有量が以下に示す範囲であることが好ましい。 In the nickel plating solution according to the present invention, the nickel salt is preferably nickel sulfamate and nickel chloride, and the content of the nickel salt and aminoalkanesulfonic acid or a derivative thereof is preferably in the following range.
　スルファミン酸ニッケル・４水和物　　　　：　２００ｇ／Ｌ～６００ｇ／Ｌ
　塩化ニッケル・６水和物　　　　　　　　　：　１ｇ／Ｌ～６ｇ／Ｌ
　アミノアルカンスルホン酸又はその誘導体　：　３０ｇ／Ｌ～１００ｇ／Ｌ Nickel sulfamate tetrahydrate: 200 g / L to 600 g / L
Nickel chloride hexahydrate: 1g / L to 6g / L
Aminoalkanesulfonic acid or its derivative: 30 g / L to 100 g / L
　また、本件発明に係るニッケルめっき液は、前記アミノアルカンスルホン酸又はその誘導体がタウリンであることが好ましい。 In the nickel plating solution according to the present invention, the aminoalkanesulfonic acid or a derivative thereof is preferably taurine.
　また、本件発明に係るニッケルめっき液は、応力調整剤を含むことも好ましい。 Also, the nickel plating solution according to the present invention preferably contains a stress adjusting agent.
　そして、本件発明に係るニッケルめっき液は、前記応力調整剤がｏ－スルホ安息香酸イミドであり、ｏ－スルホ安息香酸イミドの濃度が０．１ｇ／Ｌ～５ｇ／Ｌであることも好ましい。 In the nickel plating solution according to the present invention, it is also preferable that the stress adjusting agent is o-sulfobenzoimide and the concentration of o-sulfobenzoimide is 0.1 g / L to 5 g / L.
本件発明に係るニッケルめっき方法：　本件発明に係るニッケルめっき方法は、上述したいずれかのニッケルめっき液を用い、液温を４０℃～６０℃とし、陰極電流密度０．０５Ａ／ｄｍ２～１０Ａ／ｄｍ２で電解して、被めっき物の表面にニッケルめっき皮膜を形成することを特徴としている。 Nickel plating method according to the present invention: The nickel plating method according to the present invention uses any of the nickel plating solutions described above, the liquid temperature is set to 40 ° C to 60 ° C, and the cathode current density is 0.05 A / dm 2 to 10 A / Electrolysis is performed at dm 2 to form a nickel plating film on the surface of the object to be plated.
本件発明に係るめっき製品：　本件発明に係るめっき製品は、上述したニッケルめっき方法を用いて、ニッケルめっき皮膜を形成したことを特徴としている。 Plating product according to the present invention: The plated product according to the present invention is characterized in that a nickel plating film is formed using the nickel plating method described above.
　本件発明に係るニッケルめっき液は、水質汚濁防止法での規制物質を含まないものである。しかも、本件発明に係るニッケルめっき液は、長時間安定してめっき液の溶液ｐＨの変動を抑制することが可能で、従来のニッケルめっき液に劣らぬ生産性、めっき外観、諸特性を備えたニッケルめっき皮膜を形成することができる。 The nickel plating solution according to the present invention does not contain substances regulated by the Water Pollution Control Law. Moreover, the nickel plating solution according to the present invention can stably suppress the fluctuation of the solution pH of the plating solution for a long time, and has productivity, plating appearance, and various characteristics comparable to those of the conventional nickel plating solution. A nickel plating film can be formed.
　また、本件発明に係るニッケルめっき液は、溶液ｐＨが弱酸性から中性領域であり、且つ、ホウ酸やカルボン酸系強有機酸を含まない。このため、チップ部品にニッケルめっき皮膜を形成する際に、チップ部品のセラミックス部位の浸食も抑制でき、セラミックスで構成された保護コート層を備えるチップ部品に対しても、直接ニッケルめっきを施すことも可能である。 Further, the nickel plating solution according to the present invention has a solution pH in a weakly acidic to neutral range and does not contain boric acid or a carboxylic acid strong organic acid. For this reason, when a nickel plating film is formed on a chip part, erosion of the ceramic part of the chip part can also be suppressed, and even a chip part having a protective coating layer made of ceramics can be directly plated with nickel. Is possible.
　更に、本件発明に係るニッケルめっき方法は、従来のニッケルめっき方法と比べ、電流密度を低下させて操作する必要がない。よって、めっき皮膜の生産性も良好になる。従って、本件発明に係るニッケルめっき液を用いるニッケルめっき方法は、チップ部品の他、耐食性に不安がある被めっき物全般へのニッケルめっきに好適である。 Furthermore, the nickel plating method according to the present invention does not require operation with a reduced current density, as compared with the conventional nickel plating method. Therefore, the productivity of the plating film is also improved. Therefore, the nickel plating method using the nickel plating solution according to the present invention is suitable for nickel plating on all objects to be plated that are uneasy about corrosion resistance in addition to chip parts.
実施例１及び比較例１で得られたニッケルめっき皮膜の走査型電子顕微鏡による観察像（×１０、０００）である。It is an observation image (x10,000) by the scanning electron microscope of the nickel plating film obtained in Example 1 and Comparative Example 1. 実施例２及び比較例２で得られたニッケルめっき皮膜の走査型電子顕微鏡による観察像（×１０、０００）である。It is an observation image (x10,000) by the scanning electron microscope of the nickel plating film obtained in Example 2 and Comparative Example 2. 実施例３及び比較例３で得られたニッケルめっき皮膜の走査型電子顕微鏡による観察像（×１０、０００）である。It is an observation image (x10,000) by the scanning electron microscope of the nickel plating film obtained in Example 3 and Comparative Example 3. 実施例４及び比較例４で得られたニッケルめっき皮膜の走査型電子顕微鏡による観察像（×１０、０００）である。It is an observation image (x10,000) by the scanning electron microscope of the nickel plating film obtained in Example 4 and Comparative Example 4. 実施例５及び比較例５で得られたニッケルめっき皮膜の走査型電子顕微鏡による観察像（×１０、０００）である。It is an observation image (x10,000) by the scanning electron microscope of the nickel plating film obtained in Example 5 and Comparative Example 5.
１．本件発明に係るニッケルめっき液の形態
１－１．本件発明に係るニッケルめっき液に関する技術思想
　本件発明に係るニッケルめっき液は、ニッケルイオンの供給源である１種以上のニッケル塩とｐＨ緩衝剤とを含む電気めっき用のニッケルめっき液であって、当該ｐＨ緩衝剤がアミノアルカンスルホン酸又はその誘導体であり、且つ、溶液ｐＨが４．０～６．５であることを特徴としている。 1. 1. Form of nickel plating solution according to the present invention 1-1. Technical thought relating to nickel plating solution according to the present invention The nickel plating solution according to the present invention is a nickel plating solution for electroplating containing one or more nickel salts that are nickel ion supply sources and a pH buffer, The pH buffering agent is aminoalkanesulfonic acid or a derivative thereof, and the solution pH is 4.0 to 6.5.
　本件発明に係るニッケルめっき液では、ｐＨ緩衝剤として「アミノアルカンスルホン酸又はその誘導体」を用いることが共通の特徴である。アミノアルカンスルホン酸やその誘導体は、分子内にカチオン中心とアニオン中心をもつアミノスルホン酸類であり、溶液ｐＨが中性の領域では双性イオンの状態で存在する化合物である。そして、双性イオンは、含まれる溶液が酸性になるとアニオンになり、溶液がアルカリ性になるとカチオンになることによって、自身が含まれる溶液のｐＨを緩衝する効果を発揮する。 In the nickel plating solution according to the present invention, it is a common feature that “aminoalkanesulfonic acid or a derivative thereof” is used as a pH buffer. Aminoalkanesulfonic acid and its derivatives are aminosulfonic acids having a cation center and an anion center in the molecule, and are compounds that exist in a zwitterionic state in a neutral solution pH range. The zwitterion becomes an anion when the contained solution becomes acidic, and becomes a cation when the solution becomes alkaline, thereby exhibiting an effect of buffering the pH of the solution containing itself.
　ここで、本件発明に係るニッケルめっき液における、ｐＨ緩衝剤としての「アミノアルカンスルホン酸又はその誘導体」の含有量に関して、最初に述べておく。本件発明に係るニッケルめっき液においては、アミノアルカンスルホン酸又はその誘導体の含有量は３０ｇ／Ｌ～１００ｇ／Ｌとすることが好ましい。アミノアルカンスルホン酸又はその誘導体の含有量が３０ｇ／Ｌ未満では、ニッケルめっき液の溶液ｐＨを６．０付近に設定するとｐＨ緩衝効果を十分に発揮できない場合があるため好ましくない。一方、アミノアルカンスルホン酸又はその誘導体を１００ｇ／Ｌを超えて含有しても、溶液ｐＨの緩衝効果はすでに飽和に達しており、それ以上の効果が認められず、資源の無駄遣いとなるため好ましくない。以上のことから、ｐＨ緩衝剤としての「アミノアルカンスルホン酸又はその誘導体」の含有量を定めている。 Here, the content of “aminoalkanesulfonic acid or a derivative thereof” as a pH buffer in the nickel plating solution according to the present invention will be described first. In the nickel plating solution according to the present invention, the content of aminoalkanesulfonic acid or a derivative thereof is preferably 30 g / L to 100 g / L. If the content of aminoalkanesulfonic acid or a derivative thereof is less than 30 g / L, setting the solution pH of the nickel plating solution to around 6.0 is not preferable because the pH buffering effect may not be sufficiently exhibited. On the other hand, even if aminoalkanesulfonic acid or a derivative thereof is contained in excess of 100 g / L, the buffering effect of the solution pH has already reached saturation, and no further effect is observed, which is a waste of resources. Absent. From the above, the content of “aminoalkanesulfonic acid or a derivative thereof” as a pH buffer is determined.
　更に、本件発明に係るニッケルめっき液は、「アミノアルカンスルホン酸又はその誘導体」の中でもタウリンを用いることが好ましい。このタウリンは、「アミノアルカンスルホン酸又はその誘導体」の中でも、ニッケルめっき液の中での安定性に優れ、長期に亘る溶液品質の安定化能力に優れ、めっき操業中における溶液ｐＨの変化も少なく、良好なニッケルめっき被膜を得るのに適した添加剤である。また、タウリンは、人体の経口投与薬剤として使用されるものであり毒性はなく、市場での調達が容易で、且つ、排水処理の負荷を上昇させない化合物であるという利点がある。 Furthermore, it is preferable to use taurine among the “aminoalkanesulfonic acids or derivatives thereof” for the nickel plating solution according to the present invention. This taurine has excellent stability in nickel plating solution among “aminoalkanesulfonic acid or its derivatives”, has excellent ability to stabilize solution quality over a long period of time, and has little change in solution pH during plating operation. It is an additive suitable for obtaining a good nickel plating film. Further, taurine is used as an orally administered drug for the human body, has no toxicity, has an advantage of being a compound that is easy to procure on the market and does not increase the load of wastewater treatment.
　そして、本件発明に係るニッケルめっき液において、ニッケルイオンの供給源として用いるニッケル塩は、特に限定する必要はなく、電気めっきで形成するニッケルめっき皮膜が、要求特性を満足できるように、スルファミン酸ニッケル、塩化ニッケル、硫酸ニッケル、酢酸ニッケル等から選択し、単一で、又は混合して用いることができる。 In the nickel plating solution according to the present invention, the nickel salt used as a nickel ion supply source is not particularly limited, and the nickel plating film formed by electroplating is nickel sulfamate so that the required characteristics can be satisfied. Selected from nickel chloride, nickel sulfate, nickel acetate and the like, and can be used alone or in combination.
　更に、本件発明に係るニッケルめっき液は、溶液ｐＨが４．０～６．５であることが好ましい。ニッケルめっき液の溶液ｐＨが４．０未満の強酸領域になると、セラミックスが浸食される場合があるため、チップ部品めっきに使用できず好ましくない。一方、ニッケルめっき液の溶液ｐＨが６．５を超え、アルカリ側になると、水酸化ニッケルが生じる場合があり、溶液安定性に優れたニッケルめっき液を得ることが困難になるため好ましくない。 Furthermore, the nickel plating solution according to the present invention preferably has a solution pH of 4.0 to 6.5. If the solution pH of the nickel plating solution is in a strong acid region of less than 4.0, ceramics may be eroded, which is not preferable because it cannot be used for chip component plating. On the other hand, if the solution pH of the nickel plating solution exceeds 6.5 and becomes alkaline, nickel hydroxide may be generated, and it is difficult to obtain a nickel plating solution having excellent solution stability, which is not preferable.
１－２．本件発明に係るニッケルめっき液の具体的組成
　上述のように、本件発明に係るニッケルめっき液は、アミノアルカンスルホン酸又はその誘導体をｐＨ緩衝剤として含み、「ニッケル塩として硫酸ニッケルと塩化ニッケルとを含むワット浴系ニッケルめっき液」と、「ニッケル塩としてスルファミン酸ニッケルと塩化ニッケルとを含むスルファミン酸浴系のニッケルめっき液」とに大別できる。以下、それぞれのニッケルめっき液について詳細に説明する。なお、ｐＨ緩衝剤としての「アミノアルカンスルホン酸又はその誘導体」の含有量に関しては、いずれのニッケルめっき液においても、上述の概念の適用が可能である。 1-2. Specific Composition of Nickel Plating Solution According to the Present Invention As described above, the nickel plating solution according to the present invention contains aminoalkanesulfonic acid or a derivative thereof as a pH buffer, and “a nickel salt containing nickel sulfate and nickel chloride. The watt bath type nickel plating solution containing "and the" sulfamic acid bath type nickel plating solution containing nickel sulfamate and nickel chloride as nickel salts ". Hereinafter, each nickel plating solution will be described in detail. Regarding the content of “aminoalkanesulfonic acid or a derivative thereof” as a pH buffering agent, the above concept can be applied to any nickel plating solution.
１－２－１．ワット浴系のニッケルめっき液
　ワット浴系のニッケルめっき液は、硫酸ニッケル・６水和物を１２０ｇ／Ｌ～４８０ｇ／Ｌ、塩化ニッケル・６水和物を１５ｇ／Ｌ～７０ｇ／Ｌ含有することが好ましい。この範囲内でのワット浴系のニッケルめっき液として用いることが、電流効率、皮膜の性状、長期保存に対する溶液安定性、スラッジが容易に発生しなくなる等の観点から好ましい。硫酸ニッケル・６水和物と塩化ニッケル・６水和物との配合バランスに関して言えば、上記範囲であれば特段の問題はない。以下、硫酸ニッケル・６水和物と塩化ニッケル・６水和物との含有量の限定を行った理由を示す。 1-2-1. Watt bath type nickel plating solution The Watt bath type nickel plating solution contains 120 g / L to 480 g / L of nickel sulfate hexahydrate and 15 g / L to 70 g / L of nickel chloride hexahydrate. Is preferred. Use as a watt bath-type nickel plating solution within this range is preferable from the viewpoints of current efficiency, film properties, solution stability for long-term storage, sludge is not easily generated, and the like. As far as the blending balance of nickel sulfate hexahydrate and nickel chloride hexahydrate is concerned, there is no particular problem within the above range. The reason why the contents of nickel sulfate hexahydrate and nickel chloride hexahydrate are limited will be described below.
　当該ワット浴系のニッケルめっき液において、硫酸ニッケル・６水和物の含有量が１２０ｇ／Ｌ未満の場合には、めっき液として適正なニッケル濃度を確保するには、塩化ニッケル・６水和物の含有比率が多くなり、塩素イオン濃度が過剰になるため、内部応力が高く、格子歪みの大きく脆いニッケルめっき皮膜が得られる傾向が顕著になり好ましくない。一方、硫酸ニッケル・６水和物が４８０ｇ／Ｌを超える場合には、溶液ｐＨが６．５付近で、水酸化ニッケルが析出しやすくなるため、溶液安定性に欠けるようになり好ましくない。 When the content of nickel sulfate hexahydrate is less than 120 g / L in the watt bath type nickel plating solution, nickel chloride hexahydrate is used to ensure an appropriate nickel concentration as the plating solution. This increases the content ratio of chlorine ion and excessively increases the chlorine ion concentration. This is not preferable because a tendency to obtain a brittle nickel plating film having high internal stress and large lattice distortion is not preferable. On the other hand, when nickel sulfate hexahydrate exceeds 480 g / L, nickel hydroxide is likely to be precipitated at a solution pH of around 6.5, so that the solution stability is lacking, which is not preferable.
　当該ワット浴系のニッケルめっき液において、塩化ニッケル・６水和物が１５ｇ／Ｌ未満の場合には、復極剤としての機能を発揮できず、めっき操作中に、陽極からガスが発生し、溶液ｐＨの変動が顕著になるため好ましくない。一方、塩化ニッケル・６水和物が７０ｇ／Ｌを超える場合には、塩素イオン濃度が過剰になり、内部応力が高く、格子歪みの大きく脆いニッケルめっき皮膜が得られる傾向が大きくなり好ましくない。 When the nickel chloride hexahydrate is less than 15 g / L in the watt bath type nickel plating solution, the function as a depolarizer cannot be exhibited, and gas is generated from the anode during the plating operation. This is not preferable because the pH of the solution becomes remarkable. On the other hand, when nickel chloride hexahydrate exceeds 70 g / L, the chlorine ion concentration becomes excessive, the internal stress is high, and the tendency to obtain a brittle nickel plating film having a large lattice strain is unfavorably increased.
１－２－２．スルファミン酸浴系のニッケルめっき液
　スルファミン酸浴系のニッケルめっき液は、スルファミン酸ニッケル・４水和物を２００ｇ／Ｌ～６００ｇ／Ｌ、塩化ニッケル・６水和物を１ｇ／Ｌ～６ｇ／Ｌ含有することが好ましい。この範囲内のスルファミン酸浴系のニッケルめっき液であれば、上述のワット浴系のニッケルめっき液と同様に、電流効率、皮膜の性状、長期保存に対する溶液安定性、スラッジが容易に発生しなくなる等の観点から好ましい。また、スルファミン酸ニッケル・４水和物と塩化ニッケル・６水和物との配合バランスに関して言えば、上記範囲であれば特段の問題はない。以下、スルファミン酸ニッケル・４水和物と塩化ニッケル・６水和物との含有量の限定を行った理由を示す。 1-2-2. Nickel plating solution of sulfamic acid bath system Nickel plating solution of sulfamic acid bath system is 200g / L to 600g / L for nickel sulfamate tetrahydrate and 1g / L to 6g / L for nickel chloride hexahydrate. It is preferable to contain. In the case of a sulfamic acid bath-based nickel plating solution within this range, current efficiency, film properties, solution stability against long-term storage, and sludge are not easily generated, as with the above-described watt bath-based nickel plating solution. From the viewpoint of the above. Moreover, as far as the blending balance of nickel sulfamate tetrahydrate and nickel chloride hexahydrate is concerned, there is no particular problem within the above range. The reason why the contents of nickel sulfamate tetrahydrate and nickel chloride hexahydrate are limited will be described below.
　スルファミン酸浴系のニッケルめっき液において、スルファミン酸ニッケル・４水和物の含有量が２００ｇ／Ｌ未満の場合には、電流効率の低下が著しくなり、安定したニッケルめっき皮膜の形成が困難になるため好ましくない。一方、スルファミン酸ニッケル・４水和物が６００ｇ／Ｌを超えた場合でも、電流効率の向上、めっき操作の安定性向上等の効果が得られない。むしろ、めっき液の溶液粘度が上昇し、被めっき物に付着しためっき液の持ち出し量が増え、ニッケルめっき液中のニッケル量の管理が煩雑となり、排水処理の負荷が増大するため好ましくない。 In a sulfamic acid bath-based nickel plating solution, when the content of nickel sulfamate tetrahydrate is less than 200 g / L, the current efficiency is remarkably lowered, and it is difficult to form a stable nickel plating film. Therefore, it is not preferable. On the other hand, even when nickel sulfamate tetrahydrate exceeds 600 g / L, effects such as improvement of current efficiency and improvement of stability of plating operation cannot be obtained. Rather, the solution viscosity of the plating solution increases, the amount of the plating solution adhering to the object to be plated increases, management of the amount of nickel in the nickel plating solution becomes complicated, and the load of wastewater treatment increases, which is not preferable.
　スルファミン酸浴系のニッケルめっき液において、塩化ニッケル・６水和物の含有量が１ｇ／Ｌ未満の場合には、復極剤としての機能を発揮できず、めっき操作中に陽極からガスが発生し、溶液ｐＨの変動が見られるようになるため好ましくない。一方、塩化ニッケル・６水和物が６ｇ／Ｌを超えた場合には、塩素イオン濃度が過剰になり、内部応力が高く、格子歪みの大きく脆いニッケルめっき皮膜が得られる傾向が大きくなり好ましくない。 When the content of nickel chloride hexahydrate is less than 1 g / L in a sulfamic acid bath-based nickel plating solution, it cannot function as a depolarizer, and gas is generated from the anode during the plating operation. However, it is not preferable because a change in solution pH is observed. On the other hand, when the nickel chloride hexahydrate exceeds 6 g / L, the chlorine ion concentration becomes excessive, the internal stress is high, and the tendency to obtain a brittle nickel plating film having a large lattice distortion is undesirable. .
１－２－３．ニッケルめっき液のその他の添加剤
　一般的に、電解めっき法で得られるめっき皮膜は、その析出結晶の格子内に内部応力を備えている。本件発明に言うニッケルめっき液を用いて、所定の電解条件で得られるニッケルめっき皮膜に関しても、その析出結晶の内部には内部歪みが生じており、結果として内部応力が発生している。この内部応力は、めっき液の構成成分、液温、電解条件等の影響を受け、引張応力又は圧縮応力となる。しかし、被めっき物に対するニッケルめっき皮膜の密着性を良好なものとするという観点からは、このニッケルめっき皮膜は、応力フリー～圧縮応力の範囲の内部応力を備えることが好ましい。 1-2-3. Other Additives for Nickel Plating Solution Generally, a plating film obtained by the electrolytic plating method has an internal stress in the lattice of the precipitated crystal. With respect to the nickel plating film obtained under the predetermined electrolytic conditions using the nickel plating solution according to the present invention, internal strain is generated inside the precipitated crystal, and as a result, internal stress is generated. This internal stress is influenced by the components of the plating solution, the solution temperature, the electrolysis conditions, etc., and becomes tensile stress or compressive stress. However, from the viewpoint of improving the adhesion of the nickel plating film to the object to be plated, the nickel plating film preferably has an internal stress in the range of stress-free to compressive stress.
　即ち、ニッケルめっき液の場合、溶液ｐＨ及び塩素イオン濃度が高くなると、ニッケルめっき皮膜の内部応力が引張応力側にシフトする傾向がある。このような場合には、本件発明に係るニッケルめっき液に対して、応力調整剤を添加して用いることが好ましい。この応力調整剤は、陰極表面に吸着し、電解によって析出するニッケルめっき皮膜に包含されるといわれている。特に、ワット浴系ニッケルめっき液の場合には、ニッケルめっき皮膜の引張応力が大きくなる傾向を有すると言われている。よって、ワット浴系ニッケルめっき液に対して、応力調整剤を添加し、形成されるニッケルめっき皮膜の内部応力調整行い、ニッケルめっき皮膜と被めっき物との密着性の向上を図ることが好ましい。 That is, in the case of a nickel plating solution, when the solution pH and the chlorine ion concentration increase, the internal stress of the nickel plating film tends to shift to the tensile stress side. In such a case, it is preferable to add a stress adjusting agent to the nickel plating solution according to the present invention. This stress modifier is said to be included in the nickel plating film that is adsorbed on the cathode surface and deposited by electrolysis. In particular, in the case of a watt bath type nickel plating solution, it is said that the tensile stress of the nickel plating film tends to increase. Therefore, it is preferable to improve the adhesion between the nickel plating film and the object to be plated by adding a stress adjusting agent to the Watt bath nickel plating solution to adjust the internal stress of the nickel plating film to be formed.
　このような応力調整剤としては、ｏ－スルホ安息香酸イミド、パラトルエンスルホアミド、ベンゼンスルホン酸やナフタレントリスルホン酸等の硫黄含有有機化合物を用いることができる。中でも、本件発明に係るニッケルめっき液の場合には、応力調整剤にｏ－スルホ安息香酸イミドを用いることが好ましい。ｏ－スルホ安息香酸イミドは、上述した硫黄含有有機化合物の中では、ナトリウム塩として入手が容易で、水への溶解性も良好であり、最も応力調整効果が大きな化合物だからである。 As such a stress adjusting agent, a sulfur-containing organic compound such as o-sulfobenzoimide, paratoluenesulfamide, benzenesulfonic acid or naphthalenetrisulfonic acid can be used. In particular, in the case of the nickel plating solution according to the present invention, it is preferable to use o-sulfobenzoic imide as the stress adjusting agent. This is because o-sulfobenzoimide is easily obtained as a sodium salt among the above-mentioned sulfur-containing organic compounds, has good solubility in water, and has the greatest stress adjustment effect.
　このときのｏ－スルホ安息香酸イミドは、ニッケルめっき液中で、０．１ｇ／Ｌ～５ｇ／Ｌの濃度範囲となるように添加する。このｏ－スルホ安息香酸イミドの濃度が０．１ｇ／Ｌ未満の場合には、陰極への吸着量が少なく、応力調整剤としての効果を発揮できなくなるため好ましくない。一方、ｏ－スルホ安息香酸イミドの濃度が５ｇ／Ｌを超える場合には、ニッケルめっき皮膜が内蔵する圧縮応力は、徐々に大きくなるが、ニッケルめっき皮膜と被めっき物との密着性を改善する効果は飽和して向上しなくなる。 At this time, o-sulfobenzoic imide is added in a nickel plating solution so as to be in a concentration range of 0.1 g / L to 5 g / L. When the concentration of this o-sulfobenzoimide is less than 0.1 g / L, it is not preferable because the amount of adsorption to the cathode is small and the effect as a stress adjusting agent cannot be exhibited. On the other hand, when the concentration of o-sulfobenzoimide exceeds 5 g / L, the compressive stress contained in the nickel plating film gradually increases, but improves the adhesion between the nickel plating film and the object to be plated. The effect saturates and does not improve.
　そして、本件発明に係るニッケルめっき液では、浴組成がニッケルめっき皮膜の応力に与える影響を考慮すると、「ワット浴系ニッケルめっき液」と、「スルファミン酸浴系のニッケルめっき液」とで、当該応力調整剤の適正な添加量の範囲が異なる。即ち、ワット浴系ニッケルめっき液の場合には、応力調整剤の濃度を１ｇ／Ｌ～５ｇ／Ｌの範囲とすることが好ましい。スルファミン酸浴系ニッケルめっき液の場合には、応力調整剤の濃度を０．１ｇ／Ｌ～５ｇ／Ｌとするのがより好ましい。 Then, in the nickel plating solution according to the present invention, in consideration of the effect of the bath composition on the stress of the nickel plating film, the “watt bath type nickel plating solution” and the “sulfamic acid bath type nickel plating solution” The range of the appropriate amount of stress modifier is different. That is, in the case of a watt bath type nickel plating solution, the concentration of the stress adjusting agent is preferably in the range of 1 g / L to 5 g / L. In the case of a sulfamic acid bath type nickel plating solution, the concentration of the stress adjusting agent is more preferably 0.1 g / L to 5 g / L.
本件発明に係るニッケルめっき形態：　本件発明に係るニッケルめっき方法では、上述したいずれかのニッケルめっき液を用い、液温を４０℃～６０℃とし、陰極電流密度０．０５Ａ／ｄｍ２～１０Ａ／ｄｍ２で電解して、被めっき物の表面にニッケルめっき皮膜を形成する。このニッケルめっき方法においては、スルファミン酸浴系ニッケルめっき液ではワット浴系ニッケルめっき液よりも高電流密度での電解が可能である。しかし、各ニッケルめっき液の特徴を十分に発揮させるためには、ワット浴系ニッケルめっき液では液温を４０℃～６０℃として陰極電流密度０．０５Ａ／ｄｍ２～５Ａ／ｄｍ２で電解し、スルファミン酸浴系ニッケルめっき液では液温を４０℃～６０℃として陰極電流密度０．０５Ａ／ｄｍ２～１０Ａ／ｄｍ２で電解するのがより好ましい。 Nickel Plating Form According to the Present Invention: In the nickel plating method according to the present invention, any of the above-described nickel plating solutions is used, the solution temperature is set to 40 ° C. to 60 ° C., and the cathode current density is 0.05 A / dm 2 to 10 A / Electrolysis is performed at dm 2 to form a nickel plating film on the surface of the object to be plated. In this nickel plating method, electrolysis at a higher current density is possible with a sulfamic acid bath-based nickel plating solution than with a Watt bath-based nickel plating solution. However, in order to fully demonstrate the characteristics of each nickel plating solution, the watt bath type nickel plating solution is electrolyzed at a cathode current density of 0.05 A / dm 2 to 5 A / dm 2 at a liquid temperature of 40 ° C. to 60 ° C. In the sulfamic acid bath-based nickel plating solution, it is more preferable to perform electrolysis at a cathode current density of 0.05 A / dm 2 to 10 A / dm 2 at a liquid temperature of 40 ° C. to 60 ° C.
２．本件発明に係るめっき製品の形態
　本件発明に係るニッケルめっき液は、めっき対象となる被めっき物の種類を選ばない。よって、自動車部品に施される装飾用ニッケルめっき、プリント配線板の導体に抵抗回路を形成するためのニッケルめっき、電子部品であるチップ部品に施すニッケルめっき等の種々の電気ニッケルめっきの分野での使用が可能である。よって、本件発明に係るニッケルめっき製品とは、上述の本件発明に係るニッケルめっき液及びニッケルめっき方法を用いて、ニッケルめっき皮膜を形成した製品の全てを意味するものである。 2. Form of plated product according to the present invention The nickel plating solution according to the present invention does not select the type of the object to be plated. Therefore, in the field of various electric nickel plating such as decorative nickel plating applied to automobile parts, nickel plating for forming resistance circuits on conductors of printed wiring boards, and nickel plating applied to chip parts which are electronic parts. Can be used. Therefore, the nickel-plated product according to the present invention means all products in which a nickel plating film is formed using the nickel plating solution and the nickel plating method according to the present invention described above.
　更に、本件発明に係るニッケルめっき液の場合、溶液ｐＨが４．０～６．５の中性領域にあるという特徴を備える。よって、被めっき物の表面の材質によらず、該表面に損傷を与えにくい。この点を考慮すると、本件発明に係るニッケルめっき液は、強酸性又は強アルカリ性のめっき液の場合、損傷を受けやすいセラミック材を含む電子部品への使用が好適である。即ち、電子部品の分野における強酸又は強アルカリの場合に損傷を受けやすいチップ部品にめっきを施した場合には、セラミックスやその保護コート層の損傷が少なく、導電性部分には良好なニッケルめっき皮膜の形成が可能になる。 Furthermore, the nickel plating solution according to the present invention has a feature that the solution pH is in a neutral region of 4.0 to 6.5. Therefore, the surface is hardly damaged regardless of the material of the surface of the object to be plated. Considering this point, the nickel plating solution according to the present invention is preferably used for an electronic component including a ceramic material that is easily damaged in the case of a strongly acidic or strongly alkaline plating solution. That is, when plating is applied to chip parts that are susceptible to damage in the case of strong acids or strong alkalis in the field of electronic parts, there is little damage to the ceramic and its protective coating layer, and a good nickel plating film on the conductive part Can be formed.
　以下、上述の内容をより詳細に理解できるように、実施例と比較例とを示すが、実施例と比較例とを述べる前に、全てに共通する評価方法に関して述べておく。ニッケルめっき液の評価は、「電解前後の溶液ｐＨ変化」と、「電気めっきして得られるニッケルめっき皮膜の特性」とで評価することとした。具体的には、得られたニッケルめっき皮膜の応力、硬度、ピンホールと均一電着性を評価した。この時、皮膜応力は（株）山本鍍金試験器製のスパイラル応力計で測定し、皮膜硬度は（株）明石製作所製の微小硬度計（型式：ＭＶＫ－Ｅ）で測定した。そして、ピンホールは、面積５ｃｍ×５ｃｍサイズのニッケルめっき皮膜についてフェロキシル試験を行い、面積１ｃｍ×１ｃｍに換算して評価し、均一電着性は、（株）山本鍍金試験器製のハーリングセルで評価した。更に、ニッケルめっき皮膜の表面を、走査型電子顕微鏡（以下、「ＳＥＭ」と称する。）を用い、チルト角度０°、倍率１０，０００倍で観察した。 Hereinafter, examples and comparative examples will be shown so that the above-mentioned contents can be understood in more detail. Before describing the examples and comparative examples, the evaluation methods common to all will be described. The nickel plating solution was evaluated based on “change in solution pH before and after electrolysis” and “characteristics of the nickel plating film obtained by electroplating”. Specifically, the stress, hardness, pinhole and uniform electrodeposition of the obtained nickel plating film were evaluated. At this time, the film stress was measured with a spiral stress meter manufactured by Yamamoto Metal Testing Co., Ltd., and the film hardness was measured with a micro hardness meter (model: MVK-E) manufactured by Akashi Seisakusho. The pinhole is subjected to a ferroxyl test on a nickel plating film having an area of 5 cm × 5 cm, converted to an area of 1 cm × 1 cm, and the uniform electrodeposition is determined by a Haring cell manufactured by Yamamoto Kakin Tester Co., Ltd. evaluated. Further, the surface of the nickel plating film was observed using a scanning electron microscope (hereinafter referred to as “SEM”) at a tilt angle of 0 ° and a magnification of 10,000 times.
ニッケルめっき液の調製：　実施例１では、ワット浴系のニッケルめっき液（ＴＷ１浴）を調製した。このワット浴系のニッケルめっき液（ＴＷ１浴）は、ニッケル塩として、硫酸ニッケル・６水和物濃度が２４０ｇ／Ｌ、塩化ニッケル・６水和物濃度が４５ｇ／Ｌ、ｐＨ緩衝剤としてのタウリン濃度が６０ｇ／Ｌとし、硫酸又は水酸化ナトリウム溶液を用いて溶液ｐＨを４．５０としたものである。従って、ＴＷ１浴は、応力調整剤を含まないワット浴系のニッケルめっき液である。ＴＷ１浴の組成を、他の実施例及び比較例で調製したニッケルめっき液の組成と併せて表１に示す。 Preparation of nickel plating solution: In Example 1, a Watt-based nickel plating solution (TW1 bath) was prepared. This watt bath type nickel plating solution (TW1 bath) is nickel salt, nickel sulfate hexahydrate concentration of 240 g / L, nickel chloride hexahydrate concentration of 45 g / L, taurine as pH buffering agent. The concentration is 60 g / L, and the solution pH is 4.50 using sulfuric acid or sodium hydroxide solution. Accordingly, the TW1 bath is a watt bath-based nickel plating solution that does not contain a stress modifier. The composition of the TW1 bath is shown in Table 1 together with the compositions of the nickel plating solutions prepared in other examples and comparative examples.
ニッケルめっき皮膜の作成と評価：　ＴＷ１浴の液温を４５℃とし、陽極に金属ニッケル板を、陰極には銅のハルセル板を用いて、陰極電流密度５Ａ／ｃｍ２で１０分間電解し、厚さ２μｍのニッケルめっき皮膜を形成した。１０分間電解後のＴＷ１浴の溶液ｐＨは、４．５２であった。また、得られたニッケルめっき皮膜の応力は１１９Ｐａ、硬度はＨｖ２２１、ピンホールは３．３個／ｃｍ２、均一電着性は、１：３が３．５％、１：５が５．２％であった。電解後のＴＷ１浴の溶液ｐＨとニッケルめっき皮膜特性の評価結果を、実施例及び比較例と纏めて表２に示す。また、ニッケルめっき皮膜表面のＳＥＭ観察像を、比較例１で得られたニッケルめっき皮膜表面のＳＥＭ観察像と併せて図１（ａ）に示す。 Preparation and Evaluation of Nickel Plating Film: Electrolysis was carried out at a cathode current density of 5 A / cm 2 for 10 minutes using a TW1 bath with a liquid temperature of 45 ° C., a metal nickel plate as the anode and a copper hull cell plate as the cathode. A nickel plating film having a thickness of 2 μm was formed. The solution pH of the TW1 bath after electrolysis for 10 minutes was 4.52. The obtained nickel plating film had a stress of 119 Pa, a hardness of Hv221, a pinhole of 3.3 holes / cm 2 , and a uniform electrodeposition of 3.5% for 1: 3 and 5.2 for 1: 5. %Met. The evaluation results of the solution pH of the TW1 bath after electrolysis and the properties of the nickel plating film are shown in Table 2 together with Examples and Comparative Examples. Moreover, the SEM observation image on the surface of the nickel plating film is shown in FIG. 1A together with the SEM observation image on the surface of the nickel plating film obtained in Comparative Example 1.
ニッケルめっき液の調製：　実施例２では、実施例１で調製したＴＷ１浴に対し、更に応力調整剤としてｏ－スルホ安息香酸イミドのナトリウム塩を１ｇ／Ｌ含ませ、溶液ｐＨ４．５０のワット浴系のニッケルめっき液（ＴＷ２浴）として調製した。ＴＷ２浴の組成を、他の実施例及び比較例で調製したニッケルめっき液の組成と併せて表１に示す。 Preparation of nickel plating solution: In Example 2, the TW1 bath prepared in Example 1 further contains 1 g / L of a sodium salt of o-sulfobenzoimide as a stress adjusting agent, and a Watt bath having a solution pH of 4.50. It was prepared as a nickel plating solution (TW2 bath). The composition of the TW2 bath is shown in Table 1 together with the compositions of the nickel plating solutions prepared in other examples and comparative examples.
ニッケルめっき皮膜の作成と評価：　ＴＷ２浴を用い、実施例１と同様にして電解し、厚さ２μｍのニッケルめっき皮膜を形成した。１０分間電解後のＴＷ２浴の溶液ｐＨは、４．５３であった。また、得られたニッケルめっき皮膜の応力、硬度、ピンホールと均一電着性を実施例１と同様にして測定した。その結果、応力は－９４Ｐａ、硬度はＨｖ４５１、ピンホールは１．９個／ｃｍ２、均一電着性は、１：３が４．２％、１：５が５．５％であった。電解後のＴＷ２浴の溶液ｐＨとニッケルめっき皮膜特性の評価結果を纏めて表２に示す。更に、ニッケルめっき皮膜の表面を、実施例１と同様にして、ＳＥＭで観察した。このＳＥＭ観察像を、比較例２で得られたニッケルめっき皮膜表面のＳＥＭ観察像と併せて図２（ａ）に示す。 Preparation and Evaluation of Nickel Plating Film: Electrolysis was performed in the same manner as in Example 1 using a TW2 bath to form a nickel plating film having a thickness of 2 μm. The solution pH of the TW2 bath after electrolysis for 10 minutes was 4.53. Further, the stress, hardness, pinhole and uniform electrodeposition of the obtained nickel plating film were measured in the same manner as in Example 1. As a result, the stress was −94 Pa, the hardness was Hv451, the pinholes were 1.9 pieces / cm 2 , and the throwing power was 4.2% for 1: 3 and 5.5% for 1: 5. Table 2 summarizes the evaluation results of the solution pH of the TW2 bath after electrolysis and the properties of the nickel plating film. Furthermore, the surface of the nickel plating film was observed by SEM in the same manner as in Example 1. This SEM observation image is shown in FIG. 2A together with the SEM observation image of the nickel plating film surface obtained in Comparative Example 2.
ニッケルめっき液の調製：　実施例３では、実施例２で調製したＴＷ２浴で応力調整剤として用いたｏ－スルホ安息香酸イミドのナトリウム塩に替えてナフタレントリスルホン酸ナトリウムを含ませ、溶液ｐＨ４．５０のワット浴系のニッケルめっき液（ＴＷ３浴）として調製した。ＴＷ３浴の組成を、他の実施例及び比較例で調製したニッケルめっき液の組成と併せて表１に示す。 Preparation of nickel plating solution: In Example 3, sodium naphthalene trisulfonate was added in place of the sodium salt of o-sulfobenzoimide used as a stress modifier in the TW2 bath prepared in Example 2, and the solution pH was 4. Prepared as a 50 watt bath nickel plating solution (TW3 bath). The composition of the TW3 bath is shown in Table 1 together with the compositions of the nickel plating solutions prepared in other examples and comparative examples.
ニッケルめっき皮膜の作成と評価：　ＴＷ３浴を用い、実施例１と同様にして電解し、厚さ２μｍのニッケルめっき皮膜を形成した。１０分間電解後のＴＷ３浴の溶液ｐＨは、４．５３であった。また、得られたニッケルめっき皮膜の応力、硬度、ピンホールと均一電着性を実施例１と同様にして測定した。その結果、応力は１１１Ｐａ、硬度はＨｖ４５２、ピンホールは２．２個／ｃｍ２、均一電着性は、１：３が４．６％、１：５が６．３％であった。電解後のＴＷ３浴の溶液ｐＨとニッケルめっき皮膜特性の評価結果を表２に示す。更に、ニッケルめっき皮膜の表面を、実施例１と同様にして、ＳＥＭで観察した。このＳＥＭ観察像を、比較例３で得られたニッケルめっき皮膜表面のＳＥＭ観察像と併せて図３（ａ）に示す。 Preparation and Evaluation of Nickel Plating Film: Electrolysis was performed in the same manner as in Example 1 using a TW3 bath to form a nickel plating film having a thickness of 2 μm. The solution pH of the TW3 bath after electrolysis for 10 minutes was 4.53. Further, the stress, hardness, pinhole and uniform electrodeposition of the obtained nickel plating film were measured in the same manner as in Example 1. As a result, the stress was 111 Pa, the hardness was Hv452, the pinholes were 2.2 holes / cm 2 , and the uniform electrodeposition was 4.6% for 1: 3 and 6.3% for 1: 5. Table 2 shows the evaluation results of the solution pH of the TW3 bath and the properties of the nickel plating film after electrolysis. Furthermore, the surface of the nickel plating film was observed by SEM in the same manner as in Example 1. This SEM observation image is shown in FIG. 3A together with the SEM observation image on the surface of the nickel plating film obtained in Comparative Example 3.
ニッケルめっき液の調製：　実施例４では、ニッケル塩としてスルファミン酸ニッケル４水和物が４５０ｇ／Ｌ、塩化ニッケル６水和物が３ｇ／Ｌ、ｐＨ緩衝剤としてタウリンが６０ｇ／Ｌとし、溶液ｐＨ４．５０のスルファミン酸浴系のニッケルめっき液（ＴＳ４浴）として調製した。従って、ＴＳ４浴は、応力調整剤を含まないスルファミン酸浴系のニッケルめっき液である。溶液ｐＨは、スルファミン酸溶液又は水酸化ナトリウム溶液を用いて調整した。ＴＳ４浴の組成を、他の実施例及び比較例で調製したニッケルめっき液の組成と併せて表１に示す。 Preparation of nickel plating solution: In Example 4, nickel sulfamate tetrahydrate is 450 g / L as nickel salt, nickel chloride hexahydrate is 3 g / L, taurine as pH buffer is 60 g / L, solution pH 4 .50 sulfamic acid bath nickel plating solution (TS4 bath). Therefore, the TS4 bath is a nickel plating solution of a sulfamic acid bath system that does not contain a stress adjusting agent. The solution pH was adjusted using a sulfamic acid solution or a sodium hydroxide solution. The composition of the TS4 bath is shown in Table 1 together with the compositions of the nickel plating solutions prepared in other examples and comparative examples.
ニッケルめっき皮膜の作成と評価：　ＴＳ４浴を用い、実施例１と同様にして電解し、厚さ２μｍのニッケルめっき皮膜を形成した。１０分間電解後のＴＳ４浴の溶液ｐＨは、４．５３であった。また、得られたニッケルめっき皮膜の応力、硬度、ピンホールと均一電着性を実施例１と同様にして測定した。その結果、応力は３１．８Ｐａ、硬度はＨｖ２２８、ピンホールは１．１個／ｃｍ２、均一電着性は、１：３が４．４％、１：５が７．１％であった。電解後のＴＳ４浴の溶液ｐＨとニッケルめっき皮膜特性の評価結果を表２に示す。更に、ニッケルめっき皮膜の表面を、実施例１と同様にして、ＳＥＭで観察した。このＳＥＭ観察像を、比較例４で得られたニッケルめっき皮膜表面のＳＥＭ観察像と併せて図４（ａ）に示す。 Preparation and evaluation of nickel plating film: Using a TS4 bath, electrolysis was performed in the same manner as in Example 1 to form a nickel plating film having a thickness of 2 μm. The solution pH of the TS4 bath after 10 minutes of electrolysis was 4.53. Further, the stress, hardness, pinhole and uniform electrodeposition of the obtained nickel plating film were measured in the same manner as in Example 1. As a result, the stress was 31.8 Pa, the hardness was Hv228, the pinhole was 1.1 pieces / cm 2 , and the throwing power was 4.4% for 1: 3 and 7.1% for 1: 5. . Table 2 shows the evaluation results of the solution pH and nickel plating film characteristics of the TS4 bath after electrolysis. Furthermore, the surface of the nickel plating film was observed by SEM in the same manner as in Example 1. This SEM observation image is shown in FIG. 4A together with the SEM observation image on the surface of the nickel plating film obtained in Comparative Example 4.
浸食性の評価：　ＴＳ４浴ではチップ部品の浸食性を評価した。評価対象には、チップ部品のバリスタと低温同時焼成セラミックス（以下、「ＬＴＣＣ」と称する。）を用い、ＴＳ４浴に浸漬することによって浸食した量で評価した。 Evaluation of erosion property: TS4 bath evaluated the erosion property of chip parts. Evaluation was performed using a chip part varistor and a low-temperature co-fired ceramic (hereinafter referred to as “LTCC”), and the amount of erosion by immersion in a TS4 bath was evaluated.
　チップ部品の浸食量は、４５℃のＴＳ４浴に５時間浸漬した前後の質量変化で測定した。具体的には、攪拌している液量１００ｍｌのＴＳ４浴中に、約１０ｇを秤量済みのバリスタとＬＴＣＣを別々に５時間浸漬処理した。５時間経過後、それぞれのチップ部品の全量をＴＳ４浴から引き上げて水洗し、ペーパータオルで水切り後、循環式オーブンを用い、６０℃で３０分間乾燥した。乾燥したチップ部品の質量を測定した結果、バリスタの質量減少率は０．９％、ＬＴＣＣの質量減少率は０．１％以下であった。チップ部品の浸食量について、比較例４における評価結果と併せて表２に示す。 The erosion amount of the chip parts was measured by mass change before and after being immersed in a 45 ° C. TS4 bath for 5 hours. Specifically, about 10 g of a varistor having been weighed and LTCC were separately immersed for 5 hours in a stirring TS4 bath with a liquid volume of 100 ml. After 5 hours, the entire amount of each chip part was pulled up from the TS4 bath, washed with water, drained with a paper towel, and dried at 60 ° C. for 30 minutes using a circulation oven. As a result of measuring the mass of the dried chip part, the mass reduction rate of the varistor was 0.9%, and the mass reduction rate of LTCC was 0.1% or less. The erosion amount of the chip component is shown in Table 2 together with the evaluation result in Comparative Example 4.
ニッケルめっき液の調製：　実施例５では、実施例４で調製したＴＳ４浴に対し、更に応力調整剤としてｏ－スルホ安息香酸イミドのナトリウム塩を１ｇ／Ｌ含む、溶液ｐＨ４．５０のスルファミン酸浴系のニッケルめっき液（ＴＳ５浴）を調製した。ＴＳ５浴の組成を、他の実施例及び比較例で調製したニッケルめっき液の組成と併せて表１に示す。 Preparation of nickel plating solution: In Example 5, the sulfamic acid bath having a solution pH of 4.50 containing 1 g / L of sodium salt of o-sulfobenzoimide as a stress adjusting agent with respect to the TS4 bath prepared in Example 4. A nickel plating solution (TS5 bath) was prepared. The composition of the TS5 bath is shown in Table 1 together with the compositions of the nickel plating solutions prepared in other examples and comparative examples.
ニッケルめっき皮膜の作成と評価：　ＴＳ５浴を用い、実施例１と同様にして電解し、厚さ２μｍのニッケルめっき皮膜を形成した。１０分間電解後のＴＳ５浴の溶液ｐＨは、４．５３であった。また、得られたニッケルめっき皮膜の応力、硬度、ピンホールと均一電着性を実施例１と同様にして測定した。その結果、応力は１２４Ｐａ、硬度はＨｖ４９２、ピンホールは１．１個／ｃｍ２、均一電着性は、１：３が２．８％、１：５が３．７％であった。電解後のＴＷ５浴の溶液ｐＨとニッケルめっき皮膜特性の評価結果を表２に示す。更に、ニッケルめっき皮膜の表面を、実施例１と同様にして、ＳＥＭで観察した。このＳＥＭ観察像を、比較例５で得られたニッケルめっき皮膜表面のＳＥＭ観察像と併せて図５（ａ）に示す。 Preparation and Evaluation of Nickel Plating Film: Using a TS5 bath, electrolysis was performed in the same manner as in Example 1 to form a nickel plating film having a thickness of 2 μm. The solution pH of the TS5 bath after electrolysis for 10 minutes was 4.53. Further, the stress, hardness, pinhole and uniform electrodeposition of the obtained nickel plating film were measured in the same manner as in Example 1. As a result, the stress was 124 Pa, the hardness was Hv 492, the pinholes were 1.1 pieces / cm 2 , and the uniform electrodeposition was 2.8% for 1: 3 and 3.7% for 1: 5. Table 2 shows the evaluation results of the solution pH of the TW5 bath and the properties of the nickel plating film after electrolysis. Furthermore, the surface of the nickel plating film was observed by SEM in the same manner as in Example 1. This SEM observation image is shown in FIG. 5A together with the SEM observation image on the surface of the nickel plating film obtained in Comparative Example 5.
比較例Comparative example
＜比較例１＞
ニッケルめっき液の調製：　比較例１では、実施例１で調製したＴＷ１浴が含むｐＨ緩衝剤としてのタウリン６０ｇ／Ｌに替えて、ホウ酸が３０ｇ／Ｌとし、溶液ｐＨ４．５０のワット浴系のニッケルめっき液（ＣＷ１浴）を調製した。従って、ＣＷ１浴は、応力調整剤を含まない従来のワット浴系ニッケルめっき液である。ＣＷ１浴の組成を、実施例及び他の比較例で調製したニッケルめっき液の組成と併せて表１に示す。 <Comparative Example 1>
Preparation of nickel plating solution: In Comparative Example 1, in place of 60 g / L of taurine as a pH buffer contained in the TW1 bath prepared in Example 1, 30 g / L of boric acid and a Watt bath system having a solution pH of 4.50 A nickel plating solution (CW1 bath) was prepared. Therefore, the CW1 bath is a conventional Watt bath type nickel plating solution that does not contain a stress modifier. The composition of the CW1 bath is shown in Table 1 together with the compositions of the nickel plating solutions prepared in the examples and other comparative examples.
ニッケルめっき皮膜の作成と評価：　ＣＷ１浴を用い、実施例１と同様にして電解し、厚さ２μｍのニッケルめっき皮膜を形成した。１０分間電解後のＣＷ１浴の溶液ｐＨは、４．５７であった。また、得られたニッケルめっき皮膜の応力、硬度、ピンホールと均一電着性を実施例１と同様にして測定した。その結果、応力は１１４Ｐａ、硬度はＨｖ２２７、ピンホールは２．７個／ｃｍ２、均一電着性は、１：３が４．１％、１：５が４．５％であった。電解後のＣＷ１浴の溶液ｐＨとニッケルめっき皮膜特性の評価結果を表２に示す。更に、ニッケルめっき皮膜の表面を、実施例１と同様にして、ＳＥＭで観察した。このＳＥＭ観察像を、実施例１で得られたニッケルめっき皮膜表面のＳＥＭ観察像と併せて図１（ｂ）に示す。 Preparation and Evaluation of Nickel Plating Film: Using a CW1 bath, electrolysis was performed in the same manner as in Example 1 to form a nickel plating film having a thickness of 2 μm. The solution pH of the CW1 bath after electrolysis for 10 minutes was 4.57. Further, the stress, hardness, pinhole and uniform electrodeposition of the obtained nickel plating film were measured in the same manner as in Example 1. As a result, the stress was 114 Pa, the hardness was Hv 227, the pinhole was 2.7 pieces / cm 2 , and the throwing power was 4.1% for 1: 3 and 4.5% for 1: 5. Table 2 shows the evaluation results of the solution pH and nickel plating film characteristics of the CW1 bath after electrolysis. Furthermore, the surface of the nickel plating film was observed by SEM in the same manner as in Example 1. This SEM observation image is shown in FIG.1 (b) together with the SEM observation image of the nickel plating film surface obtained in Example 1. FIG.
＜比較例２＞
ニッケルめっき液の調製：　比較例２では、比較例１で調製したＣＷ１浴に対し、更に応力調整剤としてｏ－スルホ安息香酸イミドのナトリウム塩を１ｇ／Ｌ含む、溶液ｐＨ４．５０のワット浴系のニッケルめっき液（ＣＷ２浴）を調製した。ＣＷ２浴の組成を、実施例及び他の比較例で調製したニッケルめっき液の組成と併せて表１に示す。 <Comparative Example 2>
Preparation of Nickel Plating Solution: In Comparative Example 2, the Watt bath system having a solution pH of 4.50 containing 1 g / L of sodium salt of o-sulfobenzoimide as a stress adjusting agent with respect to the CW1 bath prepared in Comparative Example 1. A nickel plating solution (CW2 bath) was prepared. The composition of the CW2 bath is shown in Table 1 together with the compositions of the nickel plating solutions prepared in the examples and other comparative examples.
ニッケルめっき皮膜の作成と評価：　ＣＷ２浴を用い、実施例１と同様にして電解し、厚さ２μｍのニッケルめっき皮膜を形成した。１０分間電解後のＣＷ２浴の溶液ｐＨは、４．５５であった。また、得られたニッケルめっき皮膜の応力、硬度、ピンホールと均一電着性を実施例１と同様にして測定した。その結果、応力は－９２Ｐａ、硬度はＨｖ４５３、ピンホールは２．４個／ｃｍ２、均一電着性は、１：３が４．４％、１：５が７．１％であった。電解後のＣＷ２浴の溶液ｐＨとニッケルめっき皮膜特性の評価結果を表２に示す。更に、ニッケルめっき皮膜の表面を、実施例１と同様にして、ＳＥＭで観察した。このＳＥＭ観察像を、実施例２で得られたニッケルめっき皮膜表面のＳＥＭ観察像と併せて図２（ｂ）に示す。 Preparation and Evaluation of Nickel Plating Film: Electrolysis was performed in the same manner as in Example 1 using a CW2 bath to form a nickel plating film having a thickness of 2 μm. The solution pH of the CW2 bath after electrolysis for 10 minutes was 4.55. Further, the stress, hardness, pinhole and uniform electrodeposition of the obtained nickel plating film were measured in the same manner as in Example 1. As a result, the stress was −92 Pa, the hardness was Hv 453, the pinholes were 2.4 holes / cm 2 , and the throwing power was 4.4% for 1: 3 and 7.1% for 1: 5. Table 2 shows the evaluation results of the solution pH and nickel plating film characteristics of the CW2 bath after electrolysis. Furthermore, the surface of the nickel plating film was observed by SEM in the same manner as in Example 1. This SEM observation image is shown in FIG. 2B together with the SEM observation image of the nickel plating film surface obtained in Example 2.
＜比較例３＞
ニッケルめっき液の調製：　比較例３では、比較例２で調製したＣＷ２浴のｏ－スルホ安息香酸イミドのナトリウム塩に替えてナフタレントリスルホン酸ナトリウムを１ｇ／Ｌ含む、溶液ｐＨ４．５０のワット浴系のニッケルめっき液（ＣＷ３浴）を調製した。ＣＷ３浴の組成を、実施例及び他の比較例で調製したニッケルめっき液の組成と併せて表１に示す。 <Comparative Example 3>
Preparation of nickel plating solution: In Comparative Example 3, a Watt bath having a solution pH of 4.50 containing 1 g / L of sodium naphthalenetrisulfonate instead of the sodium salt of o-sulfobenzoimide in the CW2 bath prepared in Comparative Example 2 A nickel plating solution (CW3 bath) was prepared. The composition of the CW3 bath is shown in Table 1 together with the compositions of the nickel plating solutions prepared in the examples and other comparative examples.
ニッケルめっき皮膜の作成と評価：　ＣＷ３浴を用い、実施例１と同様にして電解し、厚さ２μｍのニッケルめっき皮膜を形成した。１０分間電解後のＣＷ３浴の溶液ｐＨは、４．５５であった。また、得られたニッケルめっき皮膜の応力、硬度、ピンホールと均一電着性を実施例１と同様にして測定した。その結果、応力は１１０Ｐａ、硬度はＨｖ４５５、ピンホールは２．７個／ｃｍ２、均一電着性は、１：３が３．８％、１：５が６．２％であった。電解後のＣＷ３浴の溶液ｐＨとニッケルめっき皮膜特性の評価結果を表２に示す。更に、ニッケルめっき皮膜の表面を、実施例１と同様にして、ＳＥＭで観察した。このＳＥＭ観察像を、実施例３で得られたニッケルめっき皮膜表面のＳＥＭ観察像と併せて図３（ｂ）に示す。 Preparation and Evaluation of Nickel Plating Film: Electrolysis was carried out in the same manner as in Example 1 using a CW3 bath to form a nickel plating film having a thickness of 2 μm. The solution pH of the CW3 bath after electrolysis for 10 minutes was 4.55. Further, the stress, hardness, pinhole and uniform electrodeposition of the obtained nickel plating film were measured in the same manner as in Example 1. As a result, the stress was 110 Pa, the hardness was Hv455, the pinhole was 2.7 pieces / cm 2 , and the uniform electrodeposition was 3.8% for 1: 3 and 6.2% for 1: 5. Table 2 shows the evaluation results of the solution pH and nickel plating film characteristics of the CW3 bath after electrolysis. Furthermore, the surface of the nickel plating film was observed by SEM in the same manner as in Example 1. This SEM observation image is shown in FIG. 3B together with the SEM observation image of the nickel plating film surface obtained in Example 3.
＜比較例４＞
ニッケルめっき液の調製：　比較例４では実施例４で調製したＴＷ４浴が含むｐＨ緩衝剤としてのタウリン６０ｇ／Ｌに替えて、ホウ酸が３０ｇ／Ｌとなるように、溶液ｐＨ４．５０のスルファミン酸浴系のニッケルめっき液（ＣＳ４浴）を調製した。ＣＳ４浴の組成を、実施例及び他の比較例で調製したニッケルめっき液の組成と併せて表１に示す。 <Comparative example 4>
Preparation of nickel plating solution: In Comparative Example 4, instead of 60 g / L of taurine as a pH buffer contained in the TW4 bath prepared in Example 4, sulfamine having a solution pH of 4.50 so that boric acid is 30 g / L An acid bath nickel plating solution (CS4 bath) was prepared. The composition of the CS4 bath is shown in Table 1 together with the compositions of the nickel plating solutions prepared in the examples and other comparative examples.
ニッケルめっき皮膜の作成と評価：　ＣＳ４浴を用い、実施例１と同様にして電解し、厚さ２μｍのニッケルめっき皮膜を形成した。１０分間電解後のＣＳ４浴の溶液ｐＨは、４．５５であった。また、得られたニッケルめっき皮膜の応力、硬度、ピンホールと均一電着性を実施例１と同様にして測定した。その結果、応力は３０．０Ｐａ、硬度はＨｖ２１０、ピンホールは１．３個／ｃｍ２、均一電着性は、１：３が３．９％、１：５が７．２％であった。電解後のＣＷ４浴の溶液ｐＨとニッケルめっき皮膜特性の評価結果を表２に示す。更に、ニッケルめっき皮膜の表面を、実施例１と同様にして、ＳＥＭで観察した。このＳＥＭ観察像を、実施例４で得られたニッケルめっき皮膜表面のＳＥＭ観察像と併せて図４（ｂ）に示す。 Preparation and Evaluation of Nickel Plating Film: Using a CS4 bath, electrolysis was performed in the same manner as in Example 1 to form a nickel plating film having a thickness of 2 μm. The solution pH of the CS4 bath after electrolysis for 10 minutes was 4.55. Further, the stress, hardness, pinhole and uniform electrodeposition of the obtained nickel plating film were measured in the same manner as in Example 1. As a result, the stress was 30.0 Pa, the hardness was Hv210, the pinhole was 1.3 pieces / cm 2 , and the throwing power was 3.9% for 1: 3 and 7.2% for 1: 5. . Table 2 shows the evaluation results of the solution pH and nickel plating film characteristics of the CW4 bath after electrolysis. Furthermore, the surface of the nickel plating film was observed by SEM in the same manner as in Example 1. This SEM observation image is shown in FIG. 4B together with the SEM observation image of the nickel plating film surface obtained in Example 4.
浸食性の評価：　実施例４と同様にして、ＴＳ４浴によるチップ部品の浸食性を評価した。その結果、バリスタの質量減少率は６．６％、ＬＴＣＣの質量減少率は０．２％であった。チップ部品の浸食量を、実施例４における評価結果と併せて表２に示す。 Evaluation of erosion property: In the same manner as in Example 4, the erosion property of the chip component by the TS4 bath was evaluated. As a result, the mass reduction rate of the varistor was 6.6%, and the mass reduction rate of LTCC was 0.2%. Table 2 shows the amount of erosion of the chip parts together with the evaluation results in Example 4.
＜比較例５＞
ニッケルめっき液の調製：　比較例５では実施例５で調製したＴＳ５浴の組成が含むｐＨ緩衝剤としてのタウリン６０ｇ／Ｌに替えて、ホウ酸が３０ｇ／Ｌとなるように、溶液ｐＨ４．５０のスルファミン酸浴系のニッケルめっき液（ＣＳ５浴）を調製した。ＣＳ５浴の組成を、実施例及び他の比較例で調製したニッケルめっき液の組成と併せて表１に示す。 <Comparative Example 5>
Preparation of nickel plating solution: In Comparative Example 5, in place of 60 g / L of taurine as a pH buffer contained in the composition of the TS5 bath prepared in Example 5, solution pH 4.50 so that boric acid was 30 g / L. A sulfamic acid bath nickel plating solution (CS5 bath) was prepared. The composition of the CS5 bath is shown in Table 1 together with the compositions of the nickel plating solutions prepared in the examples and other comparative examples.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
ニッケルめっき皮膜の作成と評価：　ＣＳ５浴を用い、実施例１と同様にして電解し、厚さ２μｍのニッケルめっき皮膜を形成した。１０分間電解後のＣＳ５浴の溶液ｐＨは、４．５４であった。また、得られたニッケルめっき皮膜の応力、硬度、ピンホールと均一電着性を実施例１と同様にして測定した。その結果、応力は９９．２Ｐａ、硬度はＨｖ４３２、ピンホールは０．９個／ｃｍ２、均一電着性は、１：３が２．９％、１：５が３．２％であった。電解後のＣＷ５浴の溶液ｐＨとニッケルめっき皮膜特性の評価結果を表２に示す。更に、ニッケルめっき皮膜の表面を、実施例１と同様にして、ＳＥＭで観察した。このＳＥＭ観察像を、実施例５で得られたニッケルめっき皮膜表面のＳＥＭ観察像と併せて図５（ｂ）に示す。 Preparation and Evaluation of Nickel Plating Film: Electrolysis was performed in the same manner as in Example 1 using a CS5 bath to form a nickel plating film having a thickness of 2 μm. The solution pH of the CS5 bath after electrolysis for 10 minutes was 4.54. Further, the stress, hardness, pinhole and uniform electrodeposition of the obtained nickel plating film were measured in the same manner as in Example 1. As a result, the stress was 99.2 Pa, the hardness was Hv 432, the pinhole was 0.9 pieces / cm 2 , and the throwing power was 2.9% for 1: 3 and 3.2% for 1: 5. . Table 2 shows the evaluation results of the solution pH and nickel plating film characteristics of the CW5 bath after electrolysis. Furthermore, the surface of the nickel plating film was observed by SEM in the same manner as in Example 1. This SEM observation image is shown in FIG. 5B together with the SEM observation image of the nickel plating film surface obtained in Example 5.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
＜実施例と比較例との対比１：電解前後の溶液ｐＨ変化＞
　表２に示すように、電解後のニッケルめっき液の溶液ｐＨは、実施例では０．０２～０．０３上昇し、比較例では０．０４～０．０７上昇している。また、同様の浴組成間で溶液ｐＨの上昇度合いを対比すると、実施例に対して比較例は、０．０１～０．０５高くなっている。従って、アミノアルカンスルホン酸又はその誘導体をｐＨ緩衝剤として含むニッケルめっき液は、同一の電解条件を採用した場合、従来のニッケルめっき液を用いた場合と比べて溶液ｐＨ変化が小さくなる。即ち、アミノアルカンスルホン酸又はその誘導体をｐＨ緩衝剤として含むニッケルめっき液は、長期間に亘って安定したニッケルめっきが可能なニッケルめっき液であると判断できる。 <Contrast between Example and Comparative Example 1: Change in pH of solution before and after electrolysis>
As shown in Table 2, the solution pH of the nickel plating solution after electrolysis increased by 0.02 to 0.03 in the examples, and increased by 0.04 to 0.07 in the comparative examples. Further, when the degree of increase in the solution pH is compared between similar bath compositions, the comparative example is 0.01 to 0.05 higher than the example. Therefore, a nickel plating solution containing aminoalkanesulfonic acid or a derivative thereof as a pH buffering agent has a smaller change in solution pH when the same electrolysis conditions are employed than when a conventional nickel plating solution is used. That is, it can be determined that the nickel plating solution containing aminoalkanesulfonic acid or a derivative thereof as a pH buffer is a nickel plating solution capable of stable nickel plating over a long period of time.
＜実施例と比較例との対比２：皮膜特性＞
　まず、図１～図５において、実施例で得られたニッケルめっき皮膜表面のＳＥＭ写真（ａ）と比較例で得られたニッケルめっき皮膜表面のＳＥＭ写真（ｂ）とを対比する。図１～図５を見ると、ｐＨ緩衝剤としてタウリンを用いた場合とホウ酸を用いた場合との間に大きな外観上の違いは見られない。また、表２に示すように、皮膜特性や均一電着性についても大きな違いは見られない。一方で、皮膜特性は、ワット浴系、スルファミン酸浴系のいずれにおいても応力調整剤の影響を大きく受けている。従って、ｐＨ緩衝剤として、アミノアルカンスルホン酸又はその誘導体をホウ酸に替えて用いたとしても、従来のニッケルめっき液を用いた場合と同等の皮膜特性を有するニッケルめっき皮膜を得ることができると判断できる。 <Contrast between Example and Comparative Example 2: Film Characteristics>
First, in FIG. 1 to FIG. 5, the SEM photograph (a) of the nickel plating film surface obtained in the example and the SEM photograph (b) of the nickel plating film surface obtained in the comparative example are compared. From FIG. 1 to FIG. 5, there is no significant difference in appearance between when taurine is used as a pH buffering agent and when boric acid is used. In addition, as shown in Table 2, there is no significant difference in film characteristics and throwing power. On the other hand, the film characteristics are greatly influenced by the stress modifier in both the Watt bath system and the sulfamic acid bath system. Therefore, even when aminoalkanesulfonic acid or a derivative thereof is used instead of boric acid as a pH buffer, a nickel plating film having the same film characteristics as when a conventional nickel plating solution is used can be obtained. I can judge.
＜実施例と比較例との対比３：浸食性＞
　ニッケルめっき液のチップ部品に対する浸食性は、実施例４及び比較例４のスルファミン酸浴で比較している。しかし、ｐＨ緩衝剤としてホウ酸を含む比較例４ではバリスタが６．６％、ＬＴＣＣが０．２％浸食されているのに対し、ｐＨ緩衝剤としてタウリンを含む実施例４の浸食量は、バリスタが０．９％、ＬＴＣＣが０．１％以下である。従って、カルボン酸系の浸食力がホウ酸よりも強いことを考えると、アミノアルカンスルホン酸又はその誘導体をｐＨ緩衝剤として含む実施例のニッケルめっき液は、ホウ素フリーであると同時に、チップ部品の浸食防止に対しても大きな効果を発揮するニッケルめっき液であると判断できる。 <Contrast of Example and Comparative Example 3: Erosion>
The erodibility of the nickel plating solution to the chip parts is compared in the sulfamic acid baths of Example 4 and Comparative Example 4. However, in Comparative Example 4 containing boric acid as a pH buffering agent, the varistor was 6.6% and LTCC was 0.2% eroded, whereas the erosion amount of Example 4 containing taurine as a pH buffering agent was: The varistor is 0.9% and the LTCC is 0.1% or less. Therefore, considering that the erosion power of the carboxylic acid system is stronger than that of boric acid, the nickel plating solution of the embodiment containing aminoalkanesulfonic acid or a derivative thereof as a pH buffer is boron-free and at the same time, It can be determined that the nickel plating solution exhibits a great effect in preventing erosion.
　本件発明に係るニッケルめっき液は、水質汚濁防止法での規制物質を含まないものである。従って、環境負荷・排水負荷の極めて少ないめっき液である。しかも、本件発明に係るニッケルめっき液は、長時間安定してめっき液の溶液ｐＨの変動を抑制することが可能であるため、長期間の使用が可能であり、コストパフォーマンスに優れるものである。 The nickel plating solution according to the present invention does not contain substances regulated by the Water Pollution Control Law. Therefore, it is a plating solution with very little environmental load / drainage load. In addition, the nickel plating solution according to the present invention can be used for a long period of time and has excellent cost performance because it can stably suppress fluctuations in the pH of the plating solution for a long time.
　このニッケルめっき液は、ニッケルめっきを必要とするあらゆる技術分野での使用が可能である。そして、本件発明に係るニッケルめっき液は、溶液ｐＨが弱酸性から中性領域であるため、セラミックス部位を備えるチップ部品のニッケルめっき皮膜形成に用いても、チップ部品のセラミックス部位の浸食も抑制できる。 This nickel plating solution can be used in all technical fields that require nickel plating. And since the nickel plating liquid which concerns on this invention is a solution pH from weakly acidic to neutral area | region, even if it uses it for nickel plating film formation of the chip components provided with a ceramic site | part, the erosion of the ceramic site | part of a chip component can also be suppressed. .
　また、本件発明に係るニッケルめっき方法は、従来からある既存の設備を用いて実施することの出来るものであり、新たな設備投資を要さないため、既存設備の有効利用が可能である。 Also, the nickel plating method according to the present invention can be carried out using existing existing equipment and does not require new equipment investment, so that the existing equipment can be used effectively.

Claims (8)

  1. ニッケルイオンの供給源である１種以上のニッケル塩とｐＨ緩衝剤とを含むニッケルめっき液であって、
    　当該ｐＨ緩衝剤がアミノアルカンスルホン酸又はその誘導体であり、且つ、溶液ｐＨが４．０～６．５であることを特徴とするニッケルめっき液。     A nickel plating solution containing at least one nickel salt that is a source of nickel ions and a pH buffer,
    A nickel plating solution, wherein the pH buffer is aminoalkanesulfonic acid or a derivative thereof, and the solution pH is 4.0 to 6.5.
  2. 前記ニッケル塩が硫酸ニッケルと塩化ニッケルであり、当該ニッケル塩とアミノアルカンスルホン酸又はその誘導体の含有量が以下に示す範囲である請求項１に記載のニッケルめっき液。
    　硫酸ニッケル・６水和物　　　　　　　　　：　１２０ｇ／Ｌ～４８０ｇ／Ｌ
    　塩化ニッケル・６水和物　　　　　　　　　：　１５ｇ／Ｌ～７０ｇ／Ｌ
    　アミノアルカンスルホン酸又はその誘導体　：　３０ｇ／Ｌ～１００ｇ／Ｌ     The nickel plating solution according to claim 1, wherein the nickel salt is nickel sulfate and nickel chloride, and the content of the nickel salt and aminoalkanesulfonic acid or a derivative thereof is in the range shown below.
    Nickel sulfate hexahydrate: 120 g / L to 480 g / L
    Nickel chloride hexahydrate: 15 g / L to 70 g / L
    Aminoalkanesulfonic acid or its derivative: 30 g / L to 100 g / L
  3. 前記ニッケル塩がスルファミン酸ニッケルと塩化ニッケルであり、当該ニッケル塩とアミノアルカンスルホン酸又はその誘導体の含有量が以下に示す範囲である請求項１に記載のニッケルめっき液。
    　スルファミン酸ニッケル・４水和物　　　　：　２００ｇ／Ｌ～６００ｇ／Ｌ
    　塩化ニッケル・６水和物　　　　　　　　　：　１ｇ／Ｌ～６ｇ／Ｌ
    　アミノアルカンスルホン酸又はその誘導体　：　３０ｇ／Ｌ～１００ｇ／Ｌ     The nickel plating solution according to claim 1, wherein the nickel salt is nickel sulfamate and nickel chloride, and the content of the nickel salt and aminoalkanesulfonic acid or a derivative thereof is in the range shown below.
    Nickel sulfamate tetrahydrate: 200 g / L to 600 g / L
    Nickel chloride hexahydrate: 1g / L to 6g / L
    Aminoalkanesulfonic acid or its derivative: 30 g / L to 100 g / L
  4. 前記アミノアルカンスルホン酸又はその誘導体がタウリンである請求項１～請求項３のいずれかに記載のニッケルめっき液。 The nickel plating solution according to any one of claims 1 to 3, wherein the aminoalkanesulfonic acid or a derivative thereof is taurine.
  5. 応力調整剤を含む請求項１～請求項４のいずれかに記載のニッケルめっき液。 The nickel plating solution according to any one of claims 1 to 4, comprising a stress adjusting agent.
  6. 前記応力調整剤がｏ－スルホ安息香酸イミドであり、当該ｏ－スルホ安息香酸イミドの濃度が０．１ｇ／Ｌ～５ｇ／Ｌである請求項５に記載のニッケルめっき液。 6. The nickel plating solution according to claim 5, wherein the stress adjusting agent is o-sulfobenzoimide and the concentration of the o-sulfobenzoimide is 0.1 g / L to 5 g / L.
  7. 請求項１～請求項６のいずれかに記載のニッケルめっき液を用い、液温を４０℃～６０℃とし、陰極電流密度０．０５Ａ／ｄｍ２～１０Ａ／ｄｍ２で電解して、被めっき物の表面にニッケルめっき皮膜を形成することを特徴とするニッケルめっき方法。 The nickel plating solution according to any one of claims 1 to 6 is used, electrolysis is performed at a cathode current density of 0.05 A / dm 2 to 10 A / dm 2 at a solution temperature of 40 ° C. to 60 ° C. A nickel plating method comprising forming a nickel plating film on a surface of an object.
  8. 請求項７に記載のニッケルめっき方法を用いてニッケルめっき皮膜を形成したことを特徴とするめっき製品。 A plated product, wherein a nickel plating film is formed using the nickel plating method according to claim 7.
PCT/JP2011/065425 2010-12-14 2011-07-06 Nickel plating solution and nickel plating method WO2012081274A1 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103088375A (en) * 2012-12-13 2013-05-08 苏州新区化工节能设备厂 Water electrolysis pole plate nickel-plating additive
CN111926352A (en) * 2018-06-12 2020-11-13 北京航空航天大学 Nickel plating solution

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10006141B2 (en) * 2013-06-20 2018-06-26 Baker Hughes, A Ge Company, Llc Method to produce metal matrix nanocomposite
JP2018070907A (en) * 2016-10-24 2018-05-10 ローム・アンド・ハース電子材料株式会社 Nickel plating solution
JP6760166B2 (en) * 2017-03-23 2020-09-23 トヨタ自動車株式会社 A method for forming a nickel film and a nickel solution for use in the method.
JP7376396B2 (en) * 2020-03-10 2023-11-08 トヨタ自動車株式会社 All-solid-state battery manufacturing method

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001172790A (en) * 1999-12-16 2001-06-26 Tokyo Metropolis Electroplating bath for nickel plating
JP2005220403A (en) * 2004-02-05 2005-08-18 Univ Kanagawa Plating liquid

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001172790A (en) * 1999-12-16 2001-06-26 Tokyo Metropolis Electroplating bath for nickel plating
JP2005220403A (en) * 2004-02-05 2005-08-18 Univ Kanagawa Plating liquid

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103088375A (en) * 2012-12-13 2013-05-08 苏州新区化工节能设备厂 Water electrolysis pole plate nickel-plating additive
CN111926352A (en) * 2018-06-12 2020-11-13 北京航空航天大学 Nickel plating solution

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