Satin nickel plating solution and plating method

Abstract

The purpose of the present invention is to provide a satin nickel plating solution and a plating method with which it is possible to form, in a manner that is stable over a long period of time, a plating film having a uniform and excellent appearance.　The satin nickel plating solution is characterized by containing saccharin and / or a saccharin salt, at least one acidic polysaccharide, at least one neutral polysaccharide, and at least one surfactant. The plating method is characterized in that treatment is performed using the aforementioned plating solution. The surfactant preferably contains a non-ionic surfactant, and more preferably also contains an anionic surfactant.

Description

Satin nickel plating solution and plating method

[0001] The present invention relates to a satin nickel plating solution and a plating method.

[0002] Conventional methods for forming nickel plating films with a satin appearance include a method of roughening the substrate by mechanical treatment such as sandblasting or shot blasting, a method of physically dispersing non-conductive fine particles in a nickel plating bath to cause co-deposition (composite method), and a method of adding a surfactant, such as a quaternary ammonium salt and an organic anion substance, to a nickel plating bath to form an emulsion that inhibits film deposition by electrolysis, thereby obtaining a satin appearance (emulsion method).

[0003] However, blasting is extremely expensive and is not suitable for current plating processes. The composite method is expensive to build the equipment required to uniformly disperse the fine particles, and the resulting satin finish is prone to unevenness. For this reason, satin nickel plating using the emulsion method is now the mainstream.

[0004] As examples of prior art using conventional emulsion methods, for example, Patent Document 1 discloses a nickel or nickel / cobalt plating bath containing benzyldimethyltetradecylammonium chloride and an organic anion substance. Patent Document 2 discloses a nickel or nickel / cobalt plating bath containing a quaternary ammonium salt and a sulfosuccinate ester. Patent Document 3 discloses a nickel or nickel / cobalt plating bath containing a quaternary ammonium salt and a polyether compound. Patent Document 4 discloses a nickel plating solution containing a saccharinate salt, a primary amine compound, and a cationic surfactant.

[0005] Japanese Patent Laid-Open Publication No. 3-39495 U.S. Patent No. 6,919,014B2 JP 2006-508238 A International Publication No. 2018 / 066398 Pamphlet

[0006] The conventional emulsion method described above has the problem that the time during which the plating solution can be used is very short. For example, the prior art described in Patent Documents 1 to 4 claims that the plating solution can be used for a long period of time, but in reality, significant changes in the appearance of the plating film can be observed within a few hours after the plating solution is made up. In addition, emulsion aggregates may float on the surface of the plating solution and adhere to the surface of the object to be plated, causing problems such as poor appearance. The prior art described in Patent Document 4 claims that it is easy to obtain a satin appearance stably for a long period of time, but even this technology may impair the long-term stability of the satin nickel plating solution. Therefore, there is a demand for a satin nickel plating solution that is more stable and can be used for a long period of time.

[0007] In order to solve the above-mentioned problems, an object of the present invention is to provide a satin nickel plating solution and a plating method that can stably form a plating film with uniform and good appearance over a long period of time.

[0008] As a result of intensive research conducted by the present inventors to solve the above-mentioned problems, they discovered that adding a specific compound to a nickel plating solution improves the stability of the plating solution, allowing it to be used for a long period of time and enabling the formation of a plating film that is uniform and has a good appearance, and thus completed the present invention.

[0009] That is, the present invention provides the following (1) to (10): (1) A satin nickel plating solution containing saccharin and / or a saccharin salt, at least one acidic polysaccharide, at least one neutral polysaccharide, and at least one surfactant; (2) The satin nickel plating solution of (1) above, wherein the acidic polysaccharide is one or more selected from the group consisting of carrageenan, pectin, gum arabic, xanthan gum, gellan gum, agar, tragacanth gum, alginic acid, arabic acid, and soybean polysaccharides; (3) The satin nickel plating solution of (1) or (2) above, wherein the neutral polysaccharide is one or more selected from the group consisting of starch, dextrin, pullulan, guar gum, locust bean gum, tamarind seed gum, tara gum, and chitin; and (4) The satin nickel plating solution of any of (1) to (3) above, wherein the surfactant includes a nonionic surfactant. (5) The satin nickel plating solution of (4) above, wherein the nonionic surfactant comprises one or more selected from the group consisting of polyethylene glycol, polypropylene glycol, polyoxyethylene alkyl ether, polyoxypropylene alkyl ether, polyethylene oxide-polypropylene oxide triblock copolymer, and polyoxyethylene-polyoxypropylene alkyl ether. (6) The satin nickel plating solution of any of (1) to (5) above, wherein the concentration of the acidic polysaccharide is 0.001 to 10 g / L. (7) The satin nickel plating solution of any of (1) to (6) above, wherein the concentration of the neutral polysaccharide is 0.001 to 10 g / L. (8) The satin nickel plating solution of any of (1) to (7) above, wherein the concentration of the surfactant is 0.001 to 1 g / L. (9) The satin nickel plating solution of (4) above, or any of (5) to (8) above based on the same composition, wherein the surfactant further comprises at least one anionic surfactant. (10) A plating method comprising treating an object to be plated with any one of the satin nickel plating solutions described above in (1) to (9).

[0010] The satin nickel plating solution of the present invention is stable and can be used for a long period of time, and can form a plating film with a uniform and good appearance. Furthermore, the plating method of the present invention can stably form a nickel plating film with a good satin appearance over a long period of time.

[0011] The present invention will be described in detail below based on embodiments, but the present invention is not limited to these embodiments.

[0012] 1. Plating Solution The plating solution of this embodiment is a satin nickel plating solution characterized by containing saccharin and / or a saccharin salt, at least one acidic polysaccharide, at least one neutral polysaccharide, and at least one surfactant. This can be obtained, for example, by adding the acidic polysaccharide and neutral polysaccharide to a conventionally known nickel plating solution along with saccharin and / or its salt and the surfactant. The following description will mainly focus on a satin nickel plating solution based on a general-purpose electrolytic nickel plating solution, which is a representative embodiment of the present invention.

[0013] <Nickel Plating Solution> There are no particular limitations on the nickel plating solution that serves as the base in this embodiment, and any solution containing at least one nickel ion source can be used. For example, conventionally known electrolytic nickel plating solutions (electrolytic nickel plating solutions) are also suitable as the base in this embodiment. Representative examples include known electrolytic nickel plating baths such as a nickel sulfate-based Watts bath and a nickel sulfamate bath, each having the following composition. Note that while the plating solution in the plating tank may sometimes be referred to as the "plating bath" to distinguish it from the "plating solution," in this embodiment, the two are considered to be the same, and the two terms will be used interchangeably in accordance with descriptions in various documents and commonly used names.

[0014] [Example of a typical composition of a nickel sulfate-based Watts bath] Nickel sulfate hexahydrate: 240 to 500 g / L Nickel chloride hexahydrate: 20 to 100 g / L Boric acid: 20 to 60 g / L

[0015] [Example of a typical composition of a nickel sulfamate-based bath] Nickel sulfamate: 280 to 650 g / L Nickel chloride hexahydrate: 0 to 40 g / L Boric acid: 20 to 60 g / L

[0016] The base electrolytic nickel plating solution is not limited to the above. For example, in the nickel-based bath, nickel chloride may be replaced with nickel bromide or the like. Furthermore, a metal ion source other than nickel may be contained. For example, a nickel alloy plating solution containing an ion source of cobalt, chromium, molybdenum, tungsten, or the like may also be used.

[0017] <Saccharin / Saccharin Salt> The plating solution of this embodiment contains saccharin and / or a saccharin salt (hereinafter, a chemical species that includes both of these may be referred to as "saccharin (salt)"). The inclusion of saccharin (salt) provides a good satin appearance.

[0018] There is no particular limitation on the type of saccharin salt, and various commonly used salts such as sodium salt, potassium salt, ammonium salt, etc. These saccharin salts, and even saccharin, can be used in combination of two or more kinds.

[0019] Preferably, a saccharin salt, particularly a sodium salt and / or a potassium salt, is used. The use of these saccharin salts facilitates obtaining a better satin appearance. Note that the saccharin or saccharin salt added to the plating solution may be converted to a saccharin salt or saccharin, respectively, depending on the pH of the plating bath, and this embodiment also encompasses plating solutions containing such converted forms of saccharin and / or saccharin salt.

[0020] The saccharin (salt) content is not particularly limited, but is, for example, 0.001 to 20 g / L, preferably 0.05 to 10 g / L. If the saccharin (salt) content is within this range, the plating solution can be made more stable and usable for a long period of time.

[0021] <Acidic Polysaccharides> The plating solution of this embodiment also contains at least one acidic polysaccharide. The inclusion of an acidic polysaccharide stabilizes the emulsion formed in the plating bath, making it possible to stably obtain a satin-like appearance over a long period of time. It also makes it easier to obtain a plating film with a uniform, good appearance without unevenness. The acidic polysaccharide is a polysaccharide that exhibits acidity when dissolved in water or the like, for example, a polysaccharide that contains, as a constituent sugar, a monosaccharide having a carboxyl group in the backbone within the molecule.

[0022] The acidic polysaccharides are not particularly limited, but examples thereof include carrageenan, pectin, gum arabic, xanthan gum, gellan gum, agar, tragacanth gum, alginic acid, arabic acid, soybean polysaccharides, etc., and preferably gum arabic and xanthan gum. These acidic polysaccharides may be used alone or in combination of two or more.

[0023] The content of the acidic polysaccharide is not particularly limited, but is, for example, 0.001 to 10 g / L, preferably 0.01 to 1 g / L. If the content of the acidic polysaccharide (concentration in the plating solution) is within this range, the plating solution can be made more stable and usable for a long period of time.

[0024] <Neutral Polysaccharides> The plating solution of this embodiment further contains at least one neutral polysaccharide. The inclusion of a neutral polysaccharide makes it easier to obtain a uniform satin appearance over a wide range of current densities. The neutral polysaccharide is a polysaccharide that exhibits neutrality when dissolved in water or the like, such as a polysaccharide formed by dehydration polymerization of neutral sugars such as D-glucose, D-galactose, and D-mannose.

[0025] The neutral polysaccharides are not particularly limited, but examples thereof include starch, dextrin, pullulan, guar gum, locust bean gum, tamarind seed gum, tara gum, chitin, etc., and are preferably starch and dextrin. These neutral polysaccharides may be used singly or in combination of two or more.

[0026] The content of the neutral polysaccharide is not particularly limited, but is, for example, 0.001 to 10 g / L, preferably 0.01 to 1 g / L. If the content (concentration in the plating solution) of the neutral polysaccharide is within this range, it becomes easier to obtain a more uniform satin appearance over a wider range of current densities.

[0027] <Surfactant> The plating solution of this embodiment also contains at least one surfactant. The inclusion of a surfactant forms an emulsion, making it possible to obtain a satin nickel plating solution. There are no particular limitations on the type of surfactant, and various known surfactants, such as anionic, cationic, amphoteric, and nonionic surfactants, can be used. From the viewpoint of obtaining a good satin appearance, cationic, amphoteric, or nonionic surfactants are preferred, and amphoteric or nonionic surfactants are particularly preferred, with nonionic surfactants being particularly preferred. Multiple types of surfactants may be used in combination.

[0028] The content of the surfactant is not particularly limited, but is, for example, 0.001 to 1 g / L, preferably 0.001 to 0.1 g / L. If the content of the surfactant (concentration in the plating solution) is within this range, the plating solution can be made more stable and usable for a long period of time.

[0029] [Nonionic Surfactant] It is particularly preferable that the surfactant contains a nonionic surfactant, which makes it easier to control the color tone of the satin appearance.

[0030] The nonionic surfactant is not particularly limited, but examples thereof include polyethylene glycol, polypropylene glycol, polyoxyethylene alkyl ether, polyoxypropylene alkyl ether, polyethylene oxide-polypropylene oxide triblock copolymer, polyoxyethylene-polyoxypropylene alkyl ether, etc., and polyethylene glycol and polyethylene oxide-polypropylene oxide triblock copolymer are preferred. These nonionic surfactants may be used alone or in combination of two or more. Using two or more nonionic surfactants in combination may make the plating solution more stable and usable for a long period of time.

[0031] The content of the nonionic surfactant is not particularly limited, but is, for example, 0.001 to 1 g / L, preferably 0.001 to 0.1 g / L. If the content of the nonionic surfactant is within this range, an even better satin appearance can be obtained.

[0032] [Anionic Surfactant] The plating solution of this embodiment preferably contains an anionic surfactant. The inclusion of an anionic surfactant makes it easier to suppress appearance defects such as pits. In particular, it is preferable to use a nonionic surfactant and an anionic surfactant in combination.

[0033] The anionic surfactant is not particularly limited, but examples thereof include sulfosuccinate esters represented by the following general formula (1): In the formula, R1 and R2 each independently represent hydrogen, an alkali metal ion, an alkaline earth metal ion, an ammonium ion, a carbon number C １ ~C １８ A straight or branched chain alkyl having a carbon number of C １ ~C １８ A is a chemical species selected from the group consisting of straight or branched chain alkenyl, and cyclic alkyl chains, and A is a chemical species selected from the group consisting of hydrogen, alkali metal ions, and alkaline earth metal ions.

[0034] More specific examples of sulfosuccinate esters include sodium di(1,3-dimethylbutyl)sulfosuccinate, sodium diisooctyl sulfosuccinate, sodium dihexyl sulfosuccinate, sodium diisopropyl sulfosuccinate, sodium dibutyl sulfosuccinate, etc., and preferred are sodium di(1,3-dimethylbutyl)sulfosuccinate and sodium dihexyl sulfosuccinate. These sulfosuccinate esters may be used alone or in combination of two or more.

[0035] The content of the anionic surfactant is not particularly limited, but is, for example, 0.001 to 0.5 g / L, preferably 0.01 to 0.1 g / L. When the content of the anionic surfactant is within this range, it becomes easier to further suppress appearance defects such as pits.

[0036] <Preparation of Plating Solution> The plating solution of this embodiment can be prepared from the components described above using a conventional method, and the details can be determined appropriately taking into consideration the composition and blending amounts of each component. For example, the plating solution can be prepared by adding each of the components described above to the base nickel electroplating bath described above and stirring until an emulsion is formed. Specifically, the plating solution can be prepared by stirring for about 30 to 60 minutes at a temperature between room temperature and about 60°C using a stirrer or liquid circulation equipment. There are also no particular limitations on the order in which the components are mixed.

[0037] <Other Components> In addition to the components described above, the plating solution of this embodiment may also contain known additives for plating solutions.

[0038] <Characteristics of the Plating Solution According to the Present Embodiment> The plating solution according to the present embodiment allows the emulsion that produces a satin appearance to remain stable in the plating solution for a long period of time, enabling continuous use for a long period of time compared to conventional emulsion methods. In conventional emulsion methods, the emulsion aggregates in a relatively short time, and emulsion aggregates may float on the surface of the plating bath, causing poor appearance. Therefore, to maintain a satin appearance, it is often necessary to purify the plating bath with activated carbon every few hours. On the other hand, the plating solution according to the present embodiment can avoid such purification work, which can contribute to improving productivity and reducing manufacturing costs.

[0039] Although the present invention is not limited by any particular theory, it is believed that the reason the plating solution of this embodiment is stable and usable for a long period of time is that the micellar structure and dispersion state in the emulsion are stabilized by the coexistence of various polysaccharides and surfactants. Emulsions are thermodynamically unstable systems and are prone to collapse due to factors such as differences in specific gravity between the internal and external phases. When acidic polysaccharides and neutral polysaccharides, which differ in polarity and water solubility, coexist in an emulsion, they are distributed in a balanced manner between the internal and external phases, maintaining equal specific gravities between the two phases. As a result, the emulsion may be less susceptible to collapse. Furthermore, because polysaccharides can also exhibit micelle-forming properties, multiple types of micelles with different physical properties may be generated in the emulsion when coexisting with surfactants and saccharin (salt). Therefore, even if the environment surrounding the plating solution changes, some of the micellar structure may avoid collapse, maintaining the dispersion state of the emulsion.

[0040] 2. Plating Method The plating method according to this embodiment is a method characterized by treating an object to be plated with the above-described satin nickel plating solution. For example, the object to be plated can be electroplated (electrolytically plated) using the above-described plating solution to provide satin nickel plating.

[0041] <Substrate to be plated> The substrate to be plated that can be subjected to satin nickel plating is not particularly limited as long as it is made of a material that can generally be nickel plated, and its shape is also not particularly limited. For example, various metal materials and conductive ceramic materials are of course possible, but it is also possible to use non-conductive materials such as non-conductive ceramics, glass, carbon materials, resins, rubber, and wood that have been made conductive by, for example, electroless plating or metal vapor deposition. Specific substrates include various decorative plating parts such as automobile front grilles, emblems and interior parts, and buttons used in mobile phones.

[0042] Before electroplating, the substrate may be subjected to pretreatments such as alkaline degreasing, acid activation, and etching. For example, a metal substrate may be subjected to alkaline degreasing and acid activation treatments before electroplating. Furthermore, chemical nickel plating including catalyst addition or catalytic activity can be used as a treatment for making a non-conductor conductive, and treatments such as sputtering can also be used. For example, a substrate such as a resin can be subjected to etching, catalyst addition, and catalytic activation treatments, and then chemical nickel plating can be applied before electroplating.

[0043] Here, there are no particular limitations on the type of resin used as the substrate. Examples include, but are not limited to, ABS (acrylonitrile-butadiene-styrene resin), PC (polycarbonate), PC-containing ABS, SBS (styrene-butadiene-styrene copolymer), acrylic resin, polyolefin resin such as polypropylene or polyethylene, polyphenylene oxide, polyphenylene sulfide, polyacetal, polyamide, polyimide, polyester, polyvinyl acetate, polyurethane, epoxy resin, phenolic resin, and even CFRP (carbon fiber reinforced plastic) and CNF (cellulose nanofiber)-containing resin. Among these, substrates based on ABS resin are preferred because they are easy to plate and form a copper or copper alloy surface layer on.

[0044] <Plating Treatment Conditions> The electroplating conditions are not particularly limited, and ordinary nickel plating conditions can be used. For example, the pH of the plating bath can be set within a range of 3 to 6, preferably within a range of 3.8 to 4.6. The bath temperature is, for example, within a range of 40 to 60°C, more preferably within a range of 45 to 55°C. The cathode current density is, for example, 0.01 to 50 A / dm ２ Approximately, preferably 1 to 6 A / dm ２ and more preferably in the range of 2 to 5 A / dm ２ The electrolytic treatment time is, for example, 1 to 20 minutes, preferably 8 to 15 minutes.

[0045] During electroplating, it is preferable to agitate the plating bath with a stirrer or air, or to agitate the object to be plated with a rocking device. There are no particular restrictions on the anode used in the plating process, and an electrode made of nickel or a nickel-based alloy may be used as the anode.

[0046] <Post-treatment etc.> After the satin nickel plating, finishing plating such as chrome plating, tin / cobalt plating, tin / nickel plating, gold plating or the like may be carried out according to a conventionally known method.

[0047] According to the plating method of this embodiment, a nickel plating film with a uniform and excellent satin appearance can be stably formed over a long period of time. The activated carbon treatment cycle of the plating solution can also be significantly extended, and the number of work steps and manufacturing costs can be reduced.

[0048] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0049] Example 1 Preparation of Plating Solution A nickel plating base bath having the following composition was heated to 52°C, and while maintaining liquid circulation by stirring with a stirrer (300 rpm), 11 mg / L of PEG20000 and 5.7 mg / L of polyethylene oxide-polypropylene oxide triblock copolymer (ADEKA Pluronic (registered trademark) F-68, manufactured by ADEKA Corporation) were added as nonionic surfactants to prepare a satin nickel plating bath (Bath 1 of the present invention).

[0050] <Nickel plating base bath> Nickel sulfate hexahydrate 450 g / L Nickel chloride hexahydrate 40 g / L Boric acid 45 g / L Sodium saccharin 1 g / L Gum arabic 25 mg / L Soluble starch 25 mg / L

[0051] (Electroplating Test) <Pretreatment> First, the Hull Cell brass plate was immersed in EBAPREP SK-144 (degreasing) manufactured by JCU Corporation at 55°C for 5 minutes, and then in EBAVATE V-345 (acid activity) manufactured by JCU Corporation at room temperature for 0.5 minutes.

[0052] <Electroplating (Hull Cell Test)> The pretreated Hull Cell brass plate was immersed in Inventive Bath 1, which had been prepared for 0.5 hours, under the following conditions to perform electroplating, thereby obtaining an evaluation sample (Sample No. 1) in which a satin nickel plating film was formed on the brass plate.

[0053] <Plating conditions> pH: 4.2 Bath temperature: 52°C Bath volume: 300 mL Anode: Nickel Total current: 2 A Plating time: 10 minutes Stirring: Stirring with a stirrer (300 rpm)

[0054] Using the pretreated Hull Cell brass plate and Inventive Bath 1 that had been prepared for 4 hours, electroplating was performed by immersion under the plating conditions described above, to obtain an evaluation sample (Sample No. 2) in which a satin nickel plating film was formed on the brass plate.

[0055] (Evaluation) <Visual Evaluation> The appearance of the obtained evaluation sample was visually evaluated according to the following criteria. The visual evaluation results are shown in Table 1 below.

[0056] <Visual evaluation criteria> Uniform satin appearance over the entire surface: Evaluation 〇 Roughness of the satin appearance is noticeable or the satin appearance is uneven: Evaluation ×

[0057] <Brightness Measurement> The evaluation samples (Sample No. 1 and Sample No. 2) were set in a spectrophotometer (CM-700d) manufactured by Konica Minolta, Inc. The current density of the evaluation samples was 3 A / dm２ The lightness (L*) of each sample was measured under the following conditions. The difference in lightness between Sample No. 1 and Sample No. 2 was defined as ΔL*, and the rate of change in lightness was evaluated. Table 1 shows the lightness and ΔL*.

[0058] <Brightness measurement conditions> Light source: D65 Light source receiving angle: 8° Measurement mode: SCE (specular reflection excluded)

[0059] <Gloss Measurement> The evaluation samples (Sample No. 1 and Sample No. 2) were set in a Micro Trigloss gloss meter manufactured by BYK Gardner Co., Ltd. The current density of the evaluation samples was 3 A / dm ２ The gloss (60° GU) of each of the portions was measured under the following measurement conditions. The difference in gloss between Sample No. 1 and Sample No. 2 was taken as Δ60° GU, and the rate of change in gloss was evaluated. Table 1 shows the gloss and Δ60° GU.

[0060] <Gloss measurement conditions> Light source: D65 Light source receiving angle: 60°

[0061] Example 2 The same procedures as in Example 1 were carried out except that a satin nickel plating bath (invention bath 2) was prepared and evaluation samples (samples No. 3 and No. 4) were made using 6.0 mg / L of PEG20000 and 1.0 mg / L of polyethylene oxide-polypropylene oxide triblock copolymer (ADEKA Pluronic P-103, manufactured by ADEKA Corporation) as the nonionic surfactant and the following composition as the nickel plating base bath. The results of visual evaluation, lightness, and gloss are shown in Table 1.

[0062] <Nickel plating base bath> Nickel sulfate hexahydrate 470 g / L Nickel chloride hexahydrate 40 g / L Boric acid 40 g / L Sodium saccharin 1 g / L Gum arabic 100 mg / L Pullulan 150 mg / L Sodium dihexylsulfosuccinate 15 mg / L

[0063] Example 3 The same procedures as in Example 1 were carried out except that a satin nickel plating bath (invention bath 3) was prepared and evaluation samples (samples No. 5 and No. 6) were produced using 20.0 mg / L of PEG 6000 and 2.0 mg / L of polyethylene oxide-polypropylene oxide triblock copolymer (ADEKA Pluronic F-88, manufactured by ADEKA Corporation) as the nonionic surfactant and the following composition as the nickel plating base bath. The results of visual evaluation, lightness, and gloss are shown in Table 1.

[0064] <Nickel plating base bath> Nickel sulfate hexahydrate 470 g / L Nickel chloride hexahydrate 40 g / L Boric acid 40 g / L Sodium saccharin 1 g / L Xanthan gum 10 mg / L Dextrin 150 mg / L Sodium dihexylsulfosuccinate 15 mg / L

[0065] Example 4 The same procedures as in Example 1 were carried out except that a satin nickel plating bath (invention bath 4) was prepared and evaluation samples (samples No. 7 and No. 8) were prepared using 20.0 mg / L of PEG20000 and 1.0 mg / L of polyethylene oxide-polypropylene oxide triblock copolymer (ADEKA Pluronic F-108, manufactured by ADEKA Corporation) as the nonionic surfactant and the following composition as the nickel plating base bath. The results of visual evaluation, lightness, and gloss are shown in Table 2.

[0066] <Nickel plating base bath> Nickel sulfate hexahydrate 470 g / L Nickel chloride hexahydrate 40 g / L Boric acid 40 g / L Sodium saccharin 1 g / L Gellan gum 10 mg / L Dextrin 150 mg / L Sodium dihexylsulfosuccinate 15 mg / L

[0067] Comparative Example 1 The same procedures as in Example 1 were carried out except that a satin nickel plating bath (comparative bath 1) was prepared and evaluation samples (samples No. 9 and No. 10) were produced using 5.5 mg / L of PEG20000 and 2.8 mg / L of polyethylene oxide-polypropylene oxide triblock copolymer (ADEKA Pluronic F-68, manufactured by ADEKA Corporation) as the nonionic surfactant and the following composition as the nickel plating base bath. The results of visual evaluation, lightness, and gloss are shown in Table 2.

[0068] <Nickel plating base bath> Nickel sulfate hexahydrate 470g / L Nickel chloride hexahydrate 40g / L Boric acid 40g / L Sodium saccharin 1g / L Xanthan gum 10mg / L Sodium dihexyl sulfosuccinate 15mg / L *Does not contain neutral polysaccharides

[0069] Comparative Example 2 The same procedures as in Example 1 were carried out except that a satin nickel plating bath (comparative bath 2) was prepared and evaluation samples (samples No. 11 and 12) were produced using 5.5 mg / L of PEG20000 and 2.8 mg / L of polyethylene oxide-polypropylene oxide triblock copolymer (ADEKA Pluronic F-68, manufactured by ADEKA Corporation) as the nonionic surfactant and the following composition as the nickel plating base bath. The results of visual evaluation, lightness, and gloss are shown in Table 2.

[0070] <Nickel plating base bath> Nickel sulfate hexahydrate 470g / L Nickel chloride hexahydrate 40g / L Boric acid 40g / L Sodium saccharin 1g / L Gellan gum 10mg / L Sodium dihexylsulfosuccinate 15mg / L *Does not contain neutral polysaccharides

[0071] Comparative Example 3 The same procedures as in Example 1 were carried out except that a satin nickel plating bath (comparative bath 3) was prepared and evaluation samples (samples No. 13 and 14) were produced using 11.0 mg / L of PEG20000 and 5.7 mg / L of polyethylene oxide-polypropylene oxide triblock copolymer (ADEKA Pluronic F-68, manufactured by ADEKA Corporation) as the nonionic surfactant and the following composition as the nickel plating base bath. The results of visual evaluation, lightness, and gloss are shown in Table 2.

[0072] <Nickel plating base bath> Nickel sulfate hexahydrate 450g / L Nickel chloride hexahydrate 40g / L Boric acid 45g / L Sodium saccharin 1g / L Soluble starch 112mg / L Sodium dihexyl sulfosuccinate 15mg / L *Does not contain acidic polysaccharides

[0073] Comparative Example 4 The same procedures as in Example 1 were carried out except that a satin nickel plating bath (comparative bath 4) was prepared and evaluation samples (samples No. 15 and 16) were produced using 5.5 mg / L of PEG20000 and 2.8 mg / L of polyethylene oxide-polypropylene oxide triblock copolymer (ADEKA Pluronic F-68, manufactured by ADEKA Corporation) as the nonionic surfactant and the following composition as the nickel plating base bath. The results of visual evaluation, lightness, and gloss are shown in Table 2.

[0074] <Nickel plating base bath> Nickel sulfate hexahydrate 450g / L Nickel chloride hexahydrate 40g / L Boric acid 45g / L Sodium saccharin 1g / L Pullulan 50mg / L Sodium dihexylsulfosuccinate 15mg / L *Does not contain acidic polysaccharides

[0075] Comparative Example 5 The same procedures as in Example 1 were carried out, except that evaluation samples (Sample No. 17 and Sample No. 18) were prepared using a satin nickel plating bath (Comparative Bath 5) corresponding to the prior art and having the following composition as the plating solution. Table 3 shows the visual evaluation results, lightness, and gloss.

[0076] <Prior art satin nickel plating bath> Nickel sulfate hexahydrate 470 g / L Nickel chloride hexahydrate 35 g / L Boric acid 40 g / L SATIN NICKEL EM1 (manufactured by JCU Corporation) 10 mL / L SATIN NICKEL EM2 (manufactured by JCU Corporation) 20 mL / L SATIN NICKEL DS-A (manufactured by JCU Corporation) 0.1 mL / L SATIN NICKEL DS-B (manufactured by JCU Corporation) 0.1 mL / L

[0077]

[0078]

[0079]

[0080] Tables 1 to 3 reveal that the plating solutions of Examples 1 to 4 according to the present invention can form plating films with uniform and good appearance, and can suppress color variations such as brightness and glossiness while maintaining a good appearance even 4 hours after preparation of the plating bath. In particular, Examples 1 to 3, which used gum arabic or xanthan gum, showed little color variation. On the other hand, Comparative Examples 1 and 2, which did not contain a neutral polysaccharide, showed little color variation 4 hours after preparation of the plating bath, but the satin appearance was found to be non-uniform. Furthermore, Comparative Examples 3 and 4, which did not contain an acidic polysaccharide, showed poor plating film appearance, significant color variation 4 hours after preparation of the plating bath, and noticeable roughness of the satin tone. Similarly, Comparative Example 5, which represents the prior art, showed significant color variation and noticeable roughness of the satin tone.

[0081] Example 5 (Preparation of Plating Solution) A satin nickel plating bath (Invention Bath 5) was prepared using the same nonionic surfactant and nickel plating base bath as in Example 1, in the same manner as in Example 1.

[0082] (Electroplating Test and Evaluation) The same procedures as in Example 1 were carried out, except that evaluation samples (Sample No. 19 and Sample No. 20, respectively) were prepared using Inventive Bath 5 that had been prepared 0.5 hours earlier and Inventive Bath 5 that had been prepared 24 hours earlier. Table 4 shows the visual evaluation results, lightness, and gloss.

[0083] Example 6 The same procedures as in Example 5 were carried out, except that a satin nickel plating bath (invention bath 6) was prepared and evaluation samples (samples No. 21 and 22) were produced using 9.0 mg / L of PEG 20000 and 0.6 mg / L of polyethylene oxide-polypropylene oxide triblock copolymer (ADEKA Pluronic P-85, manufactured by ADEKA Corporation) as the nonionic surfactant and the nickel plating base bath having the following composition. Table 4 shows the visual evaluation results, lightness, and gloss.

[0084] <Nickel plating base bath> Nickel sulfate hexahydrate 470 g / L Nickel chloride hexahydrate 40 g / L Boric acid 40 g / L Sodium saccharin 2 g / L Gum arabic 100 mg / L Soluble starch 25 mg / L Sodium dihexyl sulfosuccinate 15 mg / L

[0085] Example 7 The same procedures as in Example 5 were carried out, except that a satin nickel plating bath (invention bath 7) was prepared and evaluation samples (samples No. 23 and 24) were produced using 5.5 mg / L of PEG 20000 and 2.8 mg / L of polyethylene oxide-polypropylene oxide triblock copolymer (ADEKA Pluronic F-68, manufactured by ADEKA Corporation) as the nonionic surfactant and the nickel plating base bath had the following composition. Table 4 shows the visual evaluation results, lightness, and gloss.

[0086] <Nickel plating base bath> Nickel sulfate hexahydrate 470 g / L Nickel chloride hexahydrate 40 g / L Boric acid 40 g / L Sodium saccharin 2 g / L Gum arabic 100 mg / L Dextrin 150 mg / L Sodium dihexylsulfosuccinate 15 mg / L

[0087] Example 8 The same procedures as in Example 5 were carried out, except that a satin nickel plating bath (invention bath 8) was prepared and evaluation samples (samples No. 25 and 26) were prepared using only 30 mg / L of PEG 20000 as the nonionic surfactant and the nickel plating base bath having the following composition. Table 5 shows the visual evaluation results, lightness, and gloss.

[0088] <Nickel plating base bath> Nickel sulfate hexahydrate 470 g / L Nickel chloride hexahydrate 40 g / L Boric acid 40 g / L Sodium saccharin 2 g / L Gum arabic 100 mg / L Dextrin 25 mg / L Sodium dihexylsulfosuccinate 17 mg / L

[0089] Example 9 The same procedures as in Example 5 were carried out, except that a satin nickel plating bath (invention bath 9) was prepared and evaluation samples (samples No. 27 and 28) were produced using 30.0 mg / L of polyethylene oxide-polypropylene oxide triblock copolymer (ADEKA Pluronic P-103, manufactured by ADEKA Corporation) as the nonionic surfactant and the nickel plating base bath had the following composition. Table 5 shows the visual evaluation results, lightness, and gloss.

[0090] <Nickel plating base bath> Nickel sulfate hexahydrate 470 g / L Nickel chloride hexahydrate 40 g / L Boric acid 40 g / L Sodium saccharin 2 g / L Gum arabic 100 mg / L Dextrin 25 mg / L Sodium dihexylsulfosuccinate 17 mg / L

[0091] [Example 10] Using the same nonionic surfactant as in Example 7 and a nickel plating base bath of the following composition, a satin nickel plating bath (Invention Bath 10) was prepared in the same manner as in Example 5, and evaluation samples (Sample No. 29 and Sample No. 30) were prepared and evaluated in the same manner as in Example 5. Table 6 shows the visual evaluation results, lightness, and gloss.

[0092] <Nickel plating base bath> Nickel sulfate hexahydrate 470 g / L Nickel chloride hexahydrate 40 g / L Boric acid 40 g / L Sodium saccharin 2 g / L Gum arabic 50 mg / L Dextrin 150 mg / L Sodium dihexylsulfosuccinate 15 mg / L

[0093] [Example 11] Using the same nonionic surfactant as in Example 7 and a nickel plating base bath of the following composition, a satin nickel plating bath (Invention Bath 11) was prepared in the same manner as in Example 5, and evaluation samples (Sample No. 31 and Sample No. 32) were prepared and evaluated in the same manner as in Example 5. Table 6 shows the visual evaluation results, lightness, and gloss.

[0094] <Nickel plating base bath> Nickel sulfate hexahydrate 470 g / L Nickel chloride hexahydrate 40 g / L Boric acid 40 g / L Sodium saccharin 2 g / L Arabic acid 100 mg / L Dextrin 150 mg / L Sodium dihexylsulfosuccinate 15 mg / L

[0095] Comparative Example 6 A satin nickel plating bath (Comparative Bath 6) was prepared using the same nonionic surfactant as in Example 7 and a nickel plating base bath of the following composition, and evaluation samples (Sample No. 33 and Sample No. 34) were prepared in the same manner as in Example 5. Table 6 shows the visual evaluation results, lightness, and gloss.

[0096] <Nickel plating base bath> Nickel sulfate hexahydrate 470g / L Nickel chloride hexahydrate 40g / L Boric acid 40g / L Sodium saccharin 2g / L Gum arabic 100mg / L Sodium dihexylsulfosuccinate 15mg / L *Does not contain neutral polysaccharides

[0097] Comparative Example 7 A satin nickel plating bath (Comparative Bath 7) was prepared using the same nonionic surfactant as in Example 7 and a nickel plating base bath of the following composition, and evaluation samples (Sample No. 35 and Sample No. 36) were prepared in the same manner as in Example 5. Table 7 shows the visual evaluation results, lightness, and gloss.

[0098] <Nickel plating base bath> Nickel sulfate hexahydrate 470g / L Nickel chloride hexahydrate 40g / L Boric acid 40g / L Sodium saccharin 2g / L Dextrin 25mg / L Sodium dihexylsulfosuccinate 15mg / L *Does not contain acidic polysaccharides

[0099] Comparative Example 8 The same procedures as in Example 5 were carried out, except that evaluation samples (Sample No. 37 and Sample No. 38) were prepared using a satin nickel plating bath (Comparative Bath 8) corresponding to the prior art and having the following composition as the plating solution. Table 7 shows the results of the visual evaluation, lightness, and gloss.

[0100] <Prior art satin nickel plating bath> Nickel sulfate hexahydrate 470 g / L Nickel chloride hexahydrate 35 g / L Boric acid 40 g / L SATIN NICKEL EM1 (manufactured by JCU Corporation) 10 mL / L SATIN NICKEL EM2 (manufactured by JCU Corporation) 20 mL / L SATIN NICKEL DS-A (manufactured by JCU Corporation) 0.1 mL / L SATIN NICKEL DS-B (manufactured by JCU Corporation) 0.1 mL / L

[0101]

[0102]

[0103]

[0104]

[0105] Tables 4 to 7 reveal that the plating solutions of Examples 5 to 11 according to the present invention can form plating films with uniform and good appearances, and can suppress color variation while maintaining a good appearance even 24 hours after preparation of the plating bath. In particular, Examples 6 to 9 and 11, which contained acidic polysaccharides at concentrations of approximately 0.1 g / L or more, showed small variations in brightness. On the other hand, Comparative Example 6, which did not contain any neutral polysaccharides, showed little color variation 24 hours after preparation of the plating bath, but the satin appearance was uneven. Furthermore, Comparative Example 7, which did not contain any acidic polysaccharides, showed significant color variation 24 hours after preparation of the plating bath, and furthermore, the satin appearance was rough immediately after preparation of the plating bath. Comparative Example 8, which is a conventional technology, showed even greater color variation than Comparative Example 5, with the satin appearance disappearing and resulting in a nearly glossy appearance.

[0106] As described above, it has been demonstrated that the satin nickel plating solution of the present invention is stable and can be used for a long period of time, and can form a plating film that is uniform and has a good appearance.

Claims

1. A satin nickel plating solution comprising saccharin and / or a saccharin salt, at least one acidic polysaccharide, at least one neutral polysaccharide, and at least one surfactant.

2. The satin nickel plating solution according to claim 1, wherein the acidic polysaccharide is one or more selected from the group consisting of carrageenan, pectin, gum arabic, xanthan gum, gellan gum, agar, tragacanth gum, alginic acid, arabic acid, and soybean polysaccharides.

3. The satin nickel plating solution according to claim 1, wherein the neutral polysaccharide is one or more selected from the group consisting of starch, dextrin, pullulan, guar gum, locust bean gum, tamarind seed gum, tara gum, and chitin.

4. The satin nickel plating solution according to any one of claims 1 to 3, wherein the surfactant comprises a nonionic surfactant.

5. The satin nickel plating solution according to claim 4, wherein the nonionic surfactant comprises one or more surfactants selected from the group consisting of polyethylene glycol, polypropylene glycol, polyoxyethylene alkyl ether, polyoxypropylene alkyl ether, polyethylene oxide-polypropylene oxide triblock copolymer, and polyoxyethylene-polyoxypropylene alkyl ether.

6. The satin nickel plating solution according to any one of claims 1 to 3, wherein the concentration of the acidic polysaccharide is 0.001 to 10 g / L.

7. The satin nickel plating solution according to any one of claims 1 to 3, wherein the concentration of the neutral polysaccharide is 0.001 to 10 g / L.

8. The satin nickel plating solution according to any one of claims 1 to 3, wherein the concentration of the surfactant is 0.001 to 1 g / L.

9. The satin nickel plating solution of claim 4, wherein said surfactant further comprises at least one anionic surfactant.

10. A plating method comprising treating an object to be plated with the satin nickel plating solution according to any one of claims 1 to 3.

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