JP6945761B1 - Additives for composite plating solutions - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an additive for a composite plating solution, which is a liquid containing non-conductive fine particles, does not require preparation of special fine particles, and has high stability. An additive for a composite plating solution, which contains non-conductive fine particles, nickel ions, and water. [Selection diagram] Fig. 5

Description

The present invention relates to a technique for liquefying an additive containing non-conductive fine particles used in a composite plating solution.

Plating with a dull, uniform, semi-glossy or near-matte appearance is called satin-like nickel. As a method for obtaining a satin-like appearance, there is composite plating in which non-conductive fine particles are suspended in a liquid and eutectic with nickel (Non-Patent Document 1).

Further, as plating using the same non-conductive fine particles, there is microporous plating used as a base for chrome plating used as decorative plating for automobile parts, washing metal fittings and the like. With this microporous plating film, it is possible to form a large number of invisible minute pores on the surface layer of the chrome plating, disperse the corrosion current, and improve the corrosion resistance (Patent Document 1). .. This microporous plating is also a type of composite plating.

Since the fine particles used to form a satin-like appearance and microporous have a very small particle size, they are scattered into the atmosphere when added to the plating solution, exposed to workers during work, and to the surroundings. The form of the liquid additive has been long-awaited.

However, with regard to additives using water as a solvent, when non-conductive fine particles such as silica particles are added, a phenomenon has been confirmed in which they settle and precipitate after several hours and then solidify. It was incompatible as a liquid additive.

By the way, as a technique for forming microporous during plating, it is known that electroplating is performed using a plating solution containing non-conductive particles such as silica particles positively charged with aluminum hydroxide. (Patent Document 2).

However, if non-conductive fine particles positively charged by such a conventional technique are prepared in advance as an additive, they will solidify. Therefore, it is necessary to add them separately each time they are used, which is also stable. It was incompatible as a fine particle liquid additive.

Japanese Unexamined Patent Publication No. 03-291395 Japanese Unexamined Patent Publication No. 04-371597

Plating Technology Guidebook 1987 Edition, Tokyo Plating Materials Cooperative, P.151

Therefore, an object of the present invention is to provide an additive for a composite plating solution, which is a liquid containing non-conductive fine particles, does not require the preparation of special fine particles, and has high stability.

As a result of diligent research to solve the above problems, the present inventors have found that the above problems can be solved by containing nickel ions for dispersing non-conductive fine particles in a liquid, and completed the present invention. rice field.

That is, the present invention is an additive for a composite plating solution, which is characterized by containing non-conductive fine particles, nickel ions and water.

Further, the present invention is a method for preventing precipitation of non-conductive fine particles in an additive for a composite plating solution, which comprises adding nickel ions to an additive for a composite plating solution containing non-conductive fine particles and water. ..

The additive for composite plating solution of the present invention suppresses precipitation of non-conductive fine particles (delayed separation of the suspension layer of non-conductive fine particles from the supernatant: slow time to form a precipitate). And solidification of the precipitate (non-conductive fine particles do not redisperse even when shaken) can be suppressed, and a stable state can be maintained as a liquid additive.

Therefore, the additive for composite plating solution of the present invention can be used stably without being scattered in the atmosphere when added to the plating solution, or being exposed to workers or adhering to the surroundings during work. can.

In Test Example 2, it is a figure which shows the state after leaving the additive of Comparative Example 1 for 168 hours (the figure on the left and right is the same, and the figure on the right is the figure which added the explanation to the figure on the left). In Test Example 2, it is a figure which shows the state after leaving the additive of Example 1 for 168 hours (the figure on the left and right is the same, and the figure on the right is the figure which added the explanation to the figure on the left). In Test Example 2, it is a figure which shows the state after leaving the additive of Example 2 for 168 hours (the left and right figures are the same, and the figure which added the explanation to the figure on the left is the figure on the right). In Test Example 2, it is a figure which shows the state after shaking after leaving the additive of Comparative Example 1 for 168 hours (the left and right figures are the same, and the figure which added the explanation to the left figure is the right figure. It is a figure). In Test Example 2, it is a figure which shows the state after shaking after leaving the additive of Example 1 for 168 hours (the left and right figures are the same, and the figure which added the explanation to the left figure is the right figure. It is a figure). In Test Example 2, it is a figure which shows the state after shaking after leaving the additive of Example 2 for 168 hours (the left and right figures are the same, and the figure which added the explanation to the left figure is the right figure. It is a figure). It is a figure which shows the appearance of the test piece used in Test Example 3.

The additive for a composite plating solution of the present invention (hereinafter, referred to as "additive of the present invention") contains non-conductive fine particles, nickel ions, and water.

The non-conductive fine particles used in the additive of the present invention are not particularly limited, and examples thereof include metal oxides such as silicon, barium, zirconium, aluminum, and titanium, nitrides, sulfides, and inorganic salts. Among these, silicon, barium, zirconium, aluminum oxides, nitrides, sulfides, and inorganic salts are preferable from the viewpoint of effectiveness, and oxides such as silica (silicon dioxide) and zirconia (zirconium dioxide), barium sulfate, and the like are particularly preferable. Inorganic salts are preferred. One kind or two or more kinds of these non-conductive fine particles can be used.

Further, as the non-conductive fine particles, for example, commercially available products such as MP POWDER 308 and MP POWDER 309A of JCU Co., Ltd. can be used.

The average particle size of these non-conductive fine particles is not particularly limited, but is, for example, 0.1 to 10 μm, preferably 1.0 to 3.0 μm. The average particle size is a value measured by the zeta potential / particle size / molecular weight measurement system ELSZ-2000 manufactured by Otsuka Electronics Co., Ltd.

The content of the non-conductive fine particles in the additive of the present invention is not particularly limited, but is, for example, 0.01 to 20 wt% (hereinafter, simply referred to as “%”), preferably 0.05 to 10%. Further, the content of the non-conductive fine particles in the additive of the present invention can be set to a higher concentration than when the non-conductive fine particles are usually used in the composite plating solution, and in that case, for example, 5 to 50%. , Preferably 10-40%.

The content of nickel ions in the additive of the present invention is not particularly limited, but is, for example, 0.01 to 12%, preferably 0.05 to 10%.

The nickel ion supply source of the nickel ions is not particularly limited as long as it produces nickel ions when dissolved in water, and examples thereof include nickel sulfate, nickel chloride, nickel sulfamate, nickel acetate and the like. These can be used as hydrates or anhydrides. Among these, nickel sulfate hexahydrate is preferable because it is cost effective and does not contain halogen. As these nickel ion supply sources, one kind or two or more kinds can be used.

The mass ratio of the non-conductive fine particles to the nickel ions in the additive of the present invention may be appropriately set according to the type of the non-conductive fine particles. For example, when silicon dioxide is used as the non-conductive fine particles, 1: It is 0.001 to 1: 3, preferably 1: 0.003 to 1: 2.

The water used for the additive of the present invention is not particularly limited, and for example, distilled water, ion-exchanged water, ultrapure water, city water, or the like may be used.

The pH of the additive of the present invention is not particularly limited, but is preferably neutral or lower, and particularly preferably pH 6 or lower because nickel hydroxide is produced at pH 6 or higher. For the adjustment of pH, for example, an inorganic acid such as sulfuric acid, hydrochloric acid or nitric acid, an organic acid such as acetic acid, sulfamic acid or the like may be used.

The additive of the present invention can suppress the precipitation of non-conductive fine particles and the solidification of precipitates in the additive for composite plating solution containing water and non-conductive fine particles by the action of nickel ions described above. A stable state can be maintained as a liquid additive, but one or more selected from a charge-imparting agent, a surfactant, and a brightener may be further contained.

Examples of the charge-imparting agent include aluminum ions and the like. The source of this aluminum ion is not particularly limited, but for example, if it is added to a composite plating solution based on a watt bath using nickel sulfate or nickel chloride, sulfuric acid can be obtained by using polyaluminum chloride or aluminum sulfate. Little effect on ions and chloride ions.

When polyaluminum chloride is contained in the additive of the present invention, powdered polyaluminum chloride may be added, for example, PAC of Nankai Chemical Co., Ltd., Typack series of Taimei Chemicals Co., Ltd., etc. A commercially available product, which is an aqueous solution of about 10% as aluminum oxide, may be added. These polyaluminum chlorides may be added as they are or after being appropriately diluted.

The content of polyaluminum chloride in the additive of the present invention is not particularly limited, but is, for example, 0.01 to 50.0%, preferably 0.1 to 30% as aluminum oxide (for example, 0.002 as aluminum). ~ 15%, preferably 0.02-7%).

Further, when the additive of the present invention contains aluminum sulfate, powdered aluminum sulfate may be added, or liquid aluminum sulfate may be added. Commercially available products such as an aluminum sulfate solution for water use and an aluminum sulfate solution for general use of Taimei Chemicals Co., Ltd. may be added to the liquid aluminum sulfate.

The surfactant is not particularly limited, and is, for example, a nonionic surfactant such as polyethylene glycol, an anionic surfactant such as polyoxyethylene alkyl ether sodium sulfate, a cationic surfactant such as benzethonium chloride, stearylamine acetate, and dodecyltrimethylammonium chloride, and lauryl. Examples thereof include amphoteric surfactants such as betaine, lauryldimethylaminoacetic acid betaine, lauric acid amidopropyldimethylaminoacetic acid betaine, and lauryldimethylamine oxide. One kind or two or more kinds of these surfactants can be used. Among these surfactants, a positively charged cationic surfactant or an amphoteric surfactant that exhibits cationicity in the pH range to be used is preferable. By using these surfactants, more dispersibility is maintained.

The content of the surfactant in the additive of the present invention is not particularly limited, but is, for example, 0.001 to 5%, preferably 0.001 to 2%.

The brightener is not particularly limited, and examples thereof include a primary brightener and a secondary brightener used in a normal composite plating solution. Examples of the primary brightener include sulfonamide, sulfonimide, benzenesulfonic acid, alkylsulfonic acid and the like. As the primary brightener, for example, MP333 (manufactured by JCU Co., Ltd.) or the like is commercially available, and this may be used. Examples of the secondary brightener include 1,4-butynediol and coumarin. The secondary brightener contains the following functional groups (C = O, C = C, C≡C, C = N, C≡N, NC = S, N = N, -CH2-CH-O). It is an organic compound having. As the secondary brightener, for example, # 810 (manufactured by JCU Co., Ltd.) or the like is commercially available, and this may be used. These primary brighteners and secondary brighteners may be used alone or in combination of two or more.

The content of the brightener in the additive of the present invention is not particularly limited, but for example, 0.1 to 900 ml / L for a primary brightener and 0.1 to 900 ml / L for a secondary brightener. Is preferable.

Since the additive of the present invention may contain non-conductive fine particles, nickel ions and water, electrolytic nickel used in a composite plating solution such as a watt bath or a sulfamic acid bath as containing nickel ions and water. A liquid may be used.

Examples of the composition of the watt bath include the following compositions. Moreover, this watt bath may be diluted appropriately.
Nickel sulfate _{(NiSO 4 · 6H 2 O)} : 1~450g / L
Nickel chloride _{(NiCl 2 · 6H 2 O)} : 0.1~45g / L
Boric acid (H ₃ BO ₃ ): 0.1 to 45 g / L
Water: the rest

When the watt bath is used in this way, the additive of the present invention contains the non-conductive fine particles and the watt bath.

Moreover, the composition of the sulfamic acid bath includes the following composition. Moreover, this sulfamic acid bath may be diluted appropriately.
Nickel sulfamate (Ni (SO ₃ NH ₂ ) _{2.4H 2} O): 1-600 g / L
Nickel chloride _{(NiCl 2 · 6H 2 O)} : 0~15g / L
Boric acid (H ₃ BO ₃ ): 0.1 to 40 g / L
Water: the rest

When the sulfamic acid bath is used in this way, the additive of the present invention contains non-conductive fine particles and a sulfamic acid bath.

Examples of the additive of the present invention include those containing non-conductive fine particles, nickel ions and water as described above, but the following may also be used.

(1) An additive for a composite plating solution, which comprises non-conductive fine particles, nickel ions, and water.
(2) The additive for the composite plating solution according to (1), wherein the composite plating is a satin nickel plating solution and a microporous nickel plating solution.
(3) For the composite plating solution according to (1) or (2), wherein the non-conductive fine particles are at least one selected from silicon, barium, zirconium, aluminum, titanium oxides, nitrides, sulfides and inorganic salts. Additives.
(4) The composite plating solution according to any one of (1) to (3), wherein the source of nickel ions is selected from one or more of nickel sulfate hexahydrate, nickel chloride, and nickel sulfamate. Additives for.
(5) Non-conductive fine particles,
Nickel ion,
One or more selected from charge-imparting agents, surfactants and brighteners,
An additive for composite plating solutions, which is characterized by being composed of.
(6) Non-conductive fine particles,
Additives for composite plating solutions, characterized by consisting of a watt bath or a sulfamic acid bath.
(7) Non-conductive fine particles,
Watt bath or sulfamic acid bath,
One or more selected from charge-imparting agents, surfactants and brighteners,
An additive for composite plating solutions, which is characterized by being composed of.
(8) A method for preventing precipitation of non-conductive fine particles in an additive for a composite plating solution, which comprises adding nickel ions to an additive for a composite plating solution containing non-conductive fine particles and water.

The additive of the present invention described above can be prepared by stirring and mixing the above components until they become uniform.

Then, it is possible to suppress the precipitation of the non-conductive fine particles of the present invention and the solidification of the precipitate, and it is possible to maintain a stable state as a liquid additive.

The additive of the present invention can be added to the base of the composite plating solution to prepare a composite plating solution such as a satin nickel plating solution and a microporous nickel plating solution. In particular, by adding the additive of the present invention to the base of the microporous nickel plating solution to prepare the microporous nickel plating solution, it is possible to perform microporous plating with a good number of microporouss as in the conventional case. The base of the composite plating solution means a composite plating solution containing a part or all of components other than non-conductive fine particles, and a composite plating solution that becomes a composite plating solution by adding the additive of the present invention.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples and the like. In the preparation of additives in Examples and Comparative Examples, 110 mL of glass screw tube bottle (manufactured by AS ONE Corporation, 9-852-10) (hereinafter referred to as screw tube bottle) was used.

Example 1
Preparation of additives using nickel salts:
100 mL of a 500 g / L aqueous solution of nickel sulfate and 6 g of silicon dioxide powder were placed in a screw tube bottle, and the mixture was stirred and mixed until uniform to obtain an additive (pH 5.31).

Example 2
Preparation of additives using a watt bath:
100 mL of a watt bath prepared with the following composition and 6 g of silicon dioxide (average particle size: 1.5 μm) powder were placed in a screw tube bottle and stirred and mixed until uniform to obtain an additive (pH 3.69). ).

<Watt bath>
Nickel sulfate _{(NiSO 4 · 6H 2 O)} : 250g / L
Nickel chloride _{(NiCl 2 · 6H 2 O)} : 40g / L
Boric acid (H ₃ BO ₃ ): 40 g / L

Example 3
Preparation of additives using nickel salts:
Put 100 mL of a 500 g / L aqueous solution of nickel sulfate, 6 g of silicon dioxide powder, and 0.07 g of polyaluminum chloride (Nankai Chemical Co., Ltd., PAC) as aluminum in a screw tube bottle, and stir and mix until uniform. , An additive was obtained (pH 3.92).

Example 4
Preparation of additives using nickel salts:
100 mL of a 60 g / L aqueous solution of nickel sulfate, 6 g of silicon dioxide powder, and 0.07 g of polyaluminum chloride as aluminum were placed in a screw tube bottle and stirred and mixed until uniform to obtain an additive (pH 3). .99).

Example 5
Preparation of additives using nickel salts:
100 mL of a 10 g / L aqueous solution of nickel sulfate, 6 g of silicon dioxide powder, and 0.07 g of polyaluminum chloride as aluminum were placed in a screw tube bottle and stirred and mixed until uniform to obtain an additive (pH 4). .05).

Example 6
Preparation of additives using nickel salts:
100 mL of a 1 g / L aqueous solution of nickel sulfate, 6 g of silicon dioxide powder, and 0.07 g of polyaluminum chloride as aluminum were placed in a screw tube bottle and stirred and mixed until uniform to obtain an additive (pH 3). .86).

Example 7
Preparation of additives using nickel salts:
100 mL of an aqueous solution prepared with 450 g / L of nickel sulfate, 40 g / L of nickel chloride, and 40 g / L of boric acid, 6 g of silicon dioxide powder, and 0.07 g of polyaluminum chloride as aluminum were placed in a screw tube bottle and uniformly placed. The mixture was stirred and mixed until it became an additive (pH 3.62).

Example 8
Preparation of additives using nickel salts:
100 mL of an aqueous solution prepared with 250 g / L of nickel sulfate, 40 g / L of nickel chloride, and 40 g / L of boric acid, 6 g of silicon dioxide powder, and 0.07 g of polyaluminum chloride as aluminum were placed in a screw tube bottle and uniformly placed. The mixture was stirred and mixed until it became an additive (pH 3.74).

Example 9
Preparation of additives using nickel salts:
A screw tube bottle containing 100 mL of an aqueous solution prepared with 10 g / L of nickel sulfate, 1.6 g / L of nickel chloride, and 1.6 g / L of boric acid, 6 g of silicon dioxide powder, and 0.07 g of polyaluminum chloride as aluminum. And stirred and mixed until uniform (pH 3.96).

Example 10
Preparation of additives using nickel salts:
A screw tube bottle containing 100 mL of an aqueous solution prepared with 1 g / L of nickel sulfate, 0.16 g / L of nickel chloride, and 0.16 g / L of boric acid, 6 g of silicon dioxide powder, and 0.07 g of polyaluminum chloride as aluminum. And stirred and mixed until uniform (pH 3.85).

Example 11
Preparation of additives using nickel salts:
100 mL of a 500 g / L aqueous solution of nickel sulfate, 6 g of silicon dioxide powder, and 0.07 g of aluminum sulfate as aluminum were placed in a screw tube bottle and stirred and mixed until uniform to obtain an additive (pH 3. 31).

Example 12
Preparation of additives using nickel salts:
100 mL of a 60 g / L aqueous solution of nickel sulfate, 6 g of silicon dioxide powder, and 0.07 g of aluminum sulfate as aluminum were placed in a screw tube bottle and stirred and mixed until uniform to obtain an additive (pH 3. 24).

Example 13
Preparation of additives using nickel salts:
100 mL of a 10 g / L aqueous solution of nickel sulfate, 6 g of silicon dioxide powder, and 0.07 g of aluminum sulfate as aluminum were placed in a screw tube bottle and stirred and mixed until uniform to obtain an additive (pH 3. 41).

Example 14
Preparation of additives using nickel salts:
100 mL of a 1 g / L aqueous solution of nickel sulfate, 6 g of silicon dioxide powder, and 0.07 g of aluminum sulfate as aluminum were placed in a screw tube bottle and stirred and mixed until uniform to obtain an additive (pH 3. 31).

Example 15
Preparation of additives using nickel salts:
100 mL of an aqueous solution prepared with 450 g / L of nickel sulfate, 40 g / L of nickel chloride, and 40 g / L of boric acid, 6 g of silicon dioxide powder, and 0.07 g of aluminum sulfate as aluminum were placed in a screw tube bottle to make them uniform. The mixture was stirred and mixed until it became an additive (pH 3.08).

Example 16
Preparation of additives using nickel salts:
100 mL of an aqueous solution prepared with 250 g / L of nickel sulfate, 40 g / L of nickel chloride, and 40 g / L of boric acid, 6 g of silicon dioxide powder, and 0.07 g of aluminum sulfate as aluminum were placed in a screw tube bottle to make it uniform. The mixture was stirred and mixed until it became an additive (pH 3.00).

Example 17
Preparation of additives using nickel salts:
100 mL of an aqueous solution prepared with 10 g / L of nickel sulfate, 1.6 g / L of nickel chloride, and 1.6 g / L of boric acid, 6 g of silicon dioxide powder, and 0.07 g of aluminum sulfate as aluminum in a screw tube bottle. The mixture was added, stirred and mixed until uniform, and an additive was obtained (pH 3.30).

Example 18
Preparation of additives using nickel salts:
100 mL of an aqueous solution prepared with 1 g / L of nickel sulfate, 0.16 g / L of nickel chloride, and 0.16 g / L of boric acid, 6 g of silicon dioxide powder, and 0.07 g of aluminum sulfate as aluminum in a screw tube bottle. The mixture was added, stirred and mixed until uniform, and an additive was obtained (pH 3.30).

Example 19
Preparation of additives using nickel salts:
100 mL of an aqueous solution adjusted with 100 g / L of nickel sulfate and 6 g of silicon dioxide powder were placed in a screw tube bottle, and the mixture was stirred and mixed until uniform to obtain an additive (pH 5.63).

Example 20
Preparation of additives using nickel salts:
100 mL of an aqueous solution adjusted with 100 g / L of nickel sulfate and 6 g of a powder of titanium dioxide (average particle size of 0.01 μm) were placed in a screw tube bottle and stirred and mixed until uniform to obtain an additive (). pH 4.94).

Example 21
Preparation of additives using nickel salts:
100 mL of an aqueous solution adjusted with 100 g / L of nickel sulfate and 6 g of a powder of zirconium silicate (average particle size: 1.1 μm) were placed in a screw tube bottle and stirred and mixed until uniform to obtain an additive. (PH 5.64).

As a comparative example, the case where the dispersion solvent of the non-conductive fine particles does not contain nickel ions and substantially uses water as the main solvent is shown below.

Comparative Example 1
Preparation of additives prepared only with water:
100 mL of pure water and 6 g of silicon dioxide powder were placed in a screw tube bottle and stirred and mixed until uniform to obtain an additive (pH 7.17).

Comparative Example 2
Preparation of additives prepared only with water:
100 mL of pure water and 6 g of titanium dioxide powder were placed in a screw tube bottle and stirred and mixed until uniform to obtain an additive (pH 7.61).

Comparative Example 3
Preparation of additives prepared only with water:
100 mL of pure water and 6 g of zirconium silicate powder were placed in a screw tube bottle and stirred and mixed until uniform to obtain an additive (pH 6.91).

Comparative Example 4
Preparation of additives prepared only with water:
100 mL of pure water and 6 g of silicon dioxide powder were placed in a screw tube bottle, stirred and mixed until uniform, and an additive adjusted to pH 3 or less with a small amount of sulfuric acid was obtained (pH 2.34).

Comparative Example 5
Preparation of additives prepared only with water:
100 mL of pure water and 6 g of silicon dioxide powder were placed in a screw tube bottle, 0.07 g of polyaluminum chloride as aluminum was added, and the mixture was stirred and mixed until uniform to obtain an additive (pH 3.36). ..

Comparative Example 6
Preparation of additives prepared only with water:
100 mL of pure water and 6 g of silicon dioxide powder were placed in a screw tube bottle, and 0.07 g of aluminum sulfate was added as aluminum, and the mixture was stirred and mixed until uniform to obtain an additive (pH 3.84).

Test Example 1
Dispersibility test:
Examples 1 to 21 and Comparative Examples 1 to 6 were sealed in a screw tube bottle, shaken until uniform, and then the state of the additive was confirmed after 24 hours. In addition, when precipitation occurred, it was shaken again to confirm the redispersibility of the non-conductive fine particles. For shaking, the screw tube bottle was shaken up and down 30 times. The presence or absence of precipitation of the additive 24 hours after shaking was visually evaluated, and the redispersibility after shaking again was evaluated according to the following criteria. The results are shown in Table 1.

<Redispersibility evaluation criteria>
Evaluation content ○: Uniformized when shaken.
X: Not uniform even when shaken.

In Examples 1 to 21, although precipitation occurred, when the mixture was shaken again, it was easily redispersed and uniform dispersibility could be confirmed.

On the other hand, in Comparative Example 1, Comparative Example 3, and Comparative Example 4, precipitation occurred, and even if it was shaken again, it solidified and did not redisperse. Further, in Comparative Example 2, Comparative Example 5, and Comparative Example 6, although precipitation occurred, when the mixture was shaken again, it was easily redispersed and uniform dispersibility could be confirmed.

Test Example 2
Dispersibility test after long-term storage:
Examples 1 to 21 and Comparative Examples 1 to 6 were sealed in a screw tube bottle, shaken until uniform, and the state of the additive was confirmed after 168 hours. In addition, when precipitation occurred, it was shaken again to confirm the redispersibility of the non-conductive fine particles. For shaking, the screw tube bottle was shaken up and down 30 times. The presence or absence of precipitation of the additive 168 hours after shaking was visually evaluated, and the redispersibility after shaking again was evaluated based on the same criteria as in Test Example 1. The results are shown in Table 2.
Further, the results of the additive of Comparative Example 1 are shown in FIGS. 1 and 4, the result of the additive of Example 1 is shown in FIGS. 2 and 5, and the result of the additive of Example 2 is shown in FIGS. 3 and 6. rice field.

In Examples 1 to 21, although precipitation occurred, when the mixture was shaken again, it was easily redispersed and uniform dispersibility could be confirmed.

On the other hand, in Comparative Example 1, Comparative Example 3, Comparative Example 4, and Comparative Example 5, precipitation occurred, and even if it was shaken again, it solidified and did not redisperse. Further, in Comparative Example 2 and Comparative Example 5, although precipitation occurred, when the mixture was shaken again, it was easily redispersed and uniform dispersibility could be confirmed.

From the results of Test Example 1 and Test Example 2, in order to make the precipitate / sediment of the non-conductive fine particles into a liquid state with good dispersibility without solidifying, it is necessary to contain nickel ions together with the non-conductive fine particles. It was found to be effective in redispersibility.

Test Example 3
Plating test:
The additive prepared in Example 1 was added at 0.5 ml / L to a plating bath having the following composition to prepare a microporous plating solution.

<Plating bath>
Nickel sulfate _{(NiSO 4 · 6H 2 O)} : 260g / L
Nickel chloride _{(NiCl 2 · 6H 2 O)} : 45g / L
Boric acid (H ₃ BO ₃ ): 45 g / L
Brightener # 810 ^* : 3 ml / L
Brightener MP333 ^* : 10 ml / L
Polyaluminum chloride: 0.3 mg / L (as aluminum)
Bath temperature: 55 ° C
Relative density: 1.205
* Made by JCU Co., Ltd.

Next, a bent cathode test piece (brass: manufactured by Yamamoto Plating Testing Machine Co., Ltd.) having the shape shown in FIG. 7 was used as a test piece, and a microporous plating product was manufactured by the following steps.

(Solvent degreasing / acid activity)
The test piece was treated with SK-144 (manufactured by JCU Co., Ltd.) for 5 minutes to degreasing, and then treated with V-345 (manufactured by JCU Co., Ltd.) for 30 seconds to carry out acid activity.

(Glossy nickel plating)
The test piece subjected to the above degreasing / acid activity treatment was plated at 4 A / dm ² in the following nickel plating solution for 3 minutes.
<Glossy nickel plating bath>
Nickel sulfate _{(NiSO 4 · 6H 2 O)} : 260g / L
Nickel chloride _{(NiCl 2 · 6H 2 O)} : 45g / L
Boric acid (H ₃ BO ₃ ): 45 g / L
Brightener # 810 ^* : 3 ml / L
Brightener # 83 ^* : 10 ml / L
* Made by JCU Co., Ltd.

(Microporous plating)
The gloss-plated test piece was plated at 3 A / dm ² for 3 minutes in the microporous plating solution prepared above.

(Chrome plating)
The test piece subjected to the microporous nickel plating was plated at 10 A / dm ² for 3 minutes in a hexavalent chromium plating solution having the following composition.

<Hexavalent chromium plating bath>
Chromic acid anhydride (CrO ₃ ): 250 g / L
Sulfuric acid (H ₂ SO ₄ ): 1 g / L
Additive ECR 300LN ^* : 10ml / L
Mist Shut MISTSHUT NP ^* : 0.1 ml / L
* Made by JCU Co., Ltd.

(Measurement procedure 1 for the number of micropores)
The test piece after chrome plating was immersed in a copper sulfate plating solution having the following composition for 3 minutes, and then plated at 0.5 A / dm ² in the copper sulfate plating solution for 3 minutes.

<Copper sulfate plating bath>
Copper sulfate _{(CuSO 4 · 5H 2 O)} : 220g / L
Sulfuric acid (H ₂ SO ₄ ): 50 g / L
Hydrochloric acid (HCl): 0.15 ml / L

(Measuring procedure 2 for the number of micropores)
After plating with copper sulfate, the test piece was gently washed with water and air-dried, and then the number of micropores in the plating film was measured. The number of micropores was measured on the evaluation surface of the test piece, and was performed using a microscope VHX-200 manufactured by KEYENCE CORPORATION. The measurement results of the number of micropores are shown in Table 3.

With the additive of the present invention, the expected number of micropores could be obtained even when a microporous nickel plating solution was prepared by adding non-conductive fine particles in a liquid state.

The additive of the present invention can be used for preparing a composite plating solution.

Claims (6)

An additive for a composite plating solution, which contains non-conductive fine particles, nickel ions, and water. The additive for a composite plating solution according to claim 1, wherein the composite plating solution is a satin nickel plating solution or a microporous nickel plating solution. The composite according to claim 1 or 2, wherein the non-conductive fine particles are one or more of oxides, nitrides, sulfides or inorganic salts of a metal selected from the group consisting of silicon, barium, zirconium, aluminum and titanium. Additive for plating solution. The composite according to any one of claims 1 to 3, which contains one or more selected from the group consisting of hydrates or anhydrides of nickel sulfate, nickel chloride, nickel sulfamate, nickel acetate. Additive for plating solution. The additive for a composite plating solution according to any one of claims 1 to 4, further comprising one or more selected from a charge-imparting agent, a surfactant, and a brightener. A method for suppressing solidification of a precipitate of non-conductive fine particles in an additive for a composite plating solution, which comprises adding nickel ions to an additive for a composite plating solution containing non-conductive fine particles and water.

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