Aluminum-imitating electroplating solution, electroplating process and application thereof

Abstract

The application provides an aluminum-imitating electroplating solution, an electroplating process and application thereof, wherein the aluminum-imitating electroplating solution is prepared from raw materials including a metal source 380-500 g / L, a brightener 10-25 mL / L, an auxiliary brightener 1-3 mL / L, boric acid 35-45 g / L, a glossiness regulator 0.3-1.5 mL / L and deionized water according to concentration, and further including a surfactant 0.3-4.5 mL / L. The electroplating process provided by the application introduces a filtering system, the filtering system includes a secondary filtering unit and a dispersion unit, the introduction of the filtering system prolongs the use stability of the aluminum-imitating plating solution, prolongs the use cycle time of the plating solution, and further improves the flatness of the plating layer and the aluminum-imitating appearance. The aluminum-imitating plating layer prepared according to the application has excellent fineness, the color of the plating layer is more stable, has stronger metallic feeling and an aluminum-imitating alloy appearance, the plating layer also has a fingerprint-proof effect, and the overall effect is more excellent.

Description

Technical Field

[0001] This invention relates to the field of C25D3 / 00 technology, specifically to an aluminum-like electroplating solution, its electroplating process, and its application. Background Technology

[0002] Conventional electroplated products have a bright surface that displays a dazzling luster under both natural and artificial light, which can be overly glaring. However, automotive parts and furniture that often exhibit an aluminum-like appearance have coatings that differ from these high-gloss finishes. This coating is achieved through an aluminum-imitation electroplating process. This aluminum-imitation electroplating process produces a coating that does not produce glaring or dazzling spots under light, and instead presents a soft and comfortable aluminum-like appearance.

[0003] In existing electroplating processes, cationic surfactants are often added to address problems encountered during the electroplating process and improve electroplating quality. Chinese Patent CN1656255B discloses an acid electroplating bath and method for electrolytically depositing satin nickel deposits. This patent incorporates a quaternary ammonium salt cationic surfactant to improve the quality of the electroplated coating. This application proposes an aluminum-like electroplating solution, its electroplating process, and its application. By adding a fluorinated surfactant, the surface tension is lowered, effectively solving the problems of pits and bright spots in the coating, and resulting in better environmental performance. Summary of the Invention

[0004] The first aspect of this invention provides an aluminum-like electroplating solution, the raw materials of which include deionized water, a metal source, a brightener, an auxiliary brightener, boric acid, and a gloss modifier.

[0005] In a preferred embodiment, the aluminum-like electroplating solution comprises, by concentration, the following components: 380-500 g / L metal source, 10-25 mL / L brightener, 1-3 mL / L auxiliary brightener, 35-45 g / L boric acid, and 0.3-1.5 mL / L gloss modifier. In this application, the aluminum-like electroplating solution is prepared with deionized water.

[0006] In a preferred embodiment, the brightener is 20 mL / L; the auxiliary brightener is 2 mL / L; and the gloss modifier is 0.6 mL / L.

[0007] In a preferred embodiment, the metal source is a nickel source.

[0008] In a preferred embodiment, the nickel source is selected from at least one of nickel sulfate, nickel chloride, nickel sulfonate, and nickel carbonate.

[0009] In a preferred embodiment, the nickel source is a compound of nickel sulfate and nickel chloride, wherein the nickel sulfate content is 380-450 g / L and the nickel chloride content is 25-45 g / L.

[0010] More preferably, the nickel sulfate concentration is 430 g / L and the nickel chloride concentration is 34 g / L.

[0011] The applicant discovered that adding 430 g / L of nickel sulfate and 34 g / L of nickel chloride to the plating solution in this application can reduce the polarization phenomenon of the electrode anode, increase the conductivity of the plating solution, and make the electrode cathode have a higher current density, thereby reducing the defects formed on the surface of the plated parts after electroplating with the aluminum-like plating solution.

[0012] In a preferred embodiment, the boric acid is 40 g / L.

[0013] In a preferred embodiment, the brightener is selected from one or more of sodium o-benzoylsulfonylimide, bisbenzenesulfonylimide, sodium methyl disulfonate, and p-toluenesulfonamide.

[0014] In a preferred embodiment, the brightener is a compound of sodium o-benzoylsulfonylimide and bisbenzenesulfonylimide.

[0015] In a preferred embodiment, the concentration ratio of sodium o-benzoylsulfonylimide to bisbenzenesulfonylimide is 5:(1-2), and more preferably, the concentration ratio of sodium o-benzoylsulfonylimide to bisbenzenesulfonylimide is 5:1.5.

[0016] In a preferred embodiment, the auxiliary brightener is selected from one or more of sodium vinyl sulfonate, sodium allyl sulfonate, sodium propargyl sulfonate, sodium methyl allyl sulfonate, disodium nonylphenol polyoxyethylene ether succinate monoester sulfonate, and sulfosuccinate.

[0017] In a preferred embodiment, the auxiliary brightening agent is a compound of sodium allyl sulfonate and sodium propargyl sulfonate. More preferably, the concentration ratio of sodium allyl sulfonate to sodium propargyl sulfonate is (8-15):1. Even more preferably, the concentration ratio of sodium allyl sulfonate to sodium propargyl sulfonate is 10:1.

[0018] In a preferred embodiment, the raw materials of the aluminum plating solution further include a surfactant, which is selected from at least one of non-fluorinated cationic surfactants, non-fluorinated nonionic surfactants, fluorinated cationic surfactants, and fluorinated nonionic surfactants.

[0019] In a preferred embodiment, the surfactant is a mixture of a non-fluorinated cationic surfactant and a fluorinated cationic surfactant. More preferably, the weight ratio of the non-fluorinated cationic surfactant to the fluorinated cationic surfactant is 1:(0.8-1.2). Even more preferably, the weight ratio of the non-fluorinated cationic surfactant to the fluorinated cationic surfactant is 1:1.1.

[0020] In a preferred embodiment, the non-fluorinated cationic surfactant is selected from at least one of quaternary ammonium cationic surfactants, pyridine cationic surfactants, cashew phenol cationic surfactants, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, and triethylamine.

[0021] In a preferred embodiment, the non-fluorinated cationic surfactant is a quaternary ammonium salt type cationic surfactant. Examples include: dodecyl dimethyl benzyl ammonium chloride, hexadecyl dimethyl benzyl ammonium chloride, dioctyl dimethyl ammonium chloride, stearoyl dimethyl benzyl ammonium chloride, dialcyl dimethyl ammonium chloride, and dilauryl dimethyl benzyl ammonium bromide. Preferably, the quaternary ammonium salt type cationic surfactant is a mixture of dioctyl dimethyl ammonium chloride and dodecyl dimethyl benzyl ammonium chloride in a weight ratio of 1:1.

[0022] In a preferred embodiment, the non-fluorinated nonionic surfactant is selected from at least one of dodecylamine, hexadecylamine, octadecylamine, fatty acid glycerides, polyether nonionic surfactants, and alkylolamides.

[0023] In a preferred embodiment, the fluorinated cationic surfactant is a cationic fluorocarbon surfactant.

[0024] In a preferred embodiment, the fluorinated nonionic surfactant contains a perfluoroalkyl polyether.

[0025] More preferably, the fluorinated nonionic surfactant is selected from at least one of FM-21 fluorocarbon surfactant, perfluorooctyl sulfonamide polyethoxylate, perfluorohexyl sulfonamide polypropoxylate, GS-FC327 fluorocarbon surfactant, GS-823 fluorocarbon surfactant, TF380 fluorocarbon surfactant, etc.

[0026] In a preferred embodiment, the fluorinated nonionic surfactant is a compound of GS-823 fluorocarbon surfactant, GS-FC327 fluorocarbon surfactant, and TF380 fluorocarbon surfactant, added in a volume ratio of (0.3-1.5):(0.3-1.5):(0.3-1.5).

[0027] In a preferred embodiment, the volume ratio of the GS-823 fluorocarbon surfactant, GS-FC327 fluorocarbon surfactant, and TF380 fluorocarbon surfactant is 1:1:1.

[0028] In this application, GS-823 and GS-FC327 fluorocarbon surfactants were purchased from Lotte Chemical, and TF380 fluorocarbon surfactants were purchased from Shanghai Futian Chemical Technology Co., Ltd.

[0029] In this application, the fluorinated surfactant can be added to the electroplating solution alone, or it can be compounded with brightener and auxiliary brightener and added to the electroplating solution together.

[0030] In a later alternative embodiment, the fluorinated surfactant is compounded with an auxiliary brightener and then added to the electroplating solution. In this application, the volume ratio of the auxiliary brightener to the fluorinated surfactant is (15-25):(0.3-4.5).

[0031] In a preferred embodiment, the volume ratio of the auxiliary brightener to the fluorinated surfactant is 20:1.6.

[0032] During the experiment, the applicant discovered that the compound of GS-823 fluorocarbon surfactant, GS-FC327 fluorocarbon surfactant, and TF380 fluorocarbon surfactant, used as the fluorocarbon surfactant in this application, with perfluorohexyl polyoxyethylene ether and perfluorooctyl polyether as the main active substances, aggregates on the surface of droplets in the electroplating solution through the presence of long-chain ether groups and fluorine atoms on these fluorocarbon surfactants via hydrophilic and hydrophobic effects. This not only reduces the size of the droplets in the electroplating solution but also lowers the surface energy of the droplets and the surface tension of the electroplating solution due to the presence of fluorine atoms. This allows the droplets to form a dense, uniformly pitted matte coating on the surface of the workpiece during the electroplating process. Furthermore, these fluorocarbon surfactants easily migrate to the surface of the coating during the coating formation process through atomic migration, improving the anti-fouling ability of the coating and giving it an anti-fingerprint effect.

[0033] In a preferred embodiment, the raw materials of the aluminum plating solution further include a modifier, wherein the modifier is 4 mol / L.

[0034] In a preferred embodiment, the modifier is selected from at least one of quaternary ammonium salts, alkylamine salts, and aminosulfonic acids.

[0035] In a preferred embodiment, the modifier is aminosulfonic acid.

[0036] In this application, the gloss modifier is a grit agent. The specific model and manufacturer are not limited, and it can be purchased from Shenzhen Leiteng Chemical Co., Ltd.

[0037] The second aspect of this invention provides an electroplating process for an aluminum-like electroplating solution, wherein the process conditions are as follows: process temperature 50-55℃, process pH 4.0-4.5, and process current density 1-8 A / dm³. 2 .

[0038] In a preferred embodiment, the current density of the process is divided into cathode current density and anode current density. The cathode current density is 3-8 A / dm³. 2 The anode current density is 1-3 A / dm³ 2 .

[0039] In a preferred embodiment, the electroplating process is as follows:

[0040] (1) Prepare an aluminum-like electroplating solution;

[0041] (2) Electroplating is performed using an aluminum-imitation electroplating solution in conjunction with a plating solution filtration system.

[0042] In a preferred embodiment, the electroplating filtration system includes a two-stage filtration unit and a dispersion unit.

[0043] In this application, the specific process of electroplating with an aluminum-like electroplating solution and a plating solution filtration system is as follows: After electroplating, the aluminum-like electroplating solution in the electroplating tank flows through a secondary filtration unit. The secondary filtration unit filters out large agglomerates and plating slag in the plating solution. The plating solution after passing through the secondary filtration unit flows through a dispersion unit. The dispersion unit breaks down and disperses small agglomerates in the plating solution through turbulence and other means. The plating solution after passing through the dispersion unit returns to the electroplating tank for electroplating again.

[0044] In a preferred embodiment, the diameter of the large-sized aggregates is ≥15μm, and the diameter of the small-sized aggregates is <15μm.

[0045] During the experiment, the applicant discovered that introducing a plating solution filtration system into the electroplating process can filter out plating slag and large-sized agglomerated droplets generated after prolonged electroplating, thus preventing plating slag from settling on the surface of the plated parts and forming burrs and a grainy texture. It can also prevent large droplets from forming unevenly sized pits on the surface of the plated parts during the electroplating process, thereby reducing the smooth appearance of the plating layer.

[0046] The third aspect of this invention proposes an application of an aluminum-like electroplating solution for surface electroplating of automotive parts and furniture, particularly suitable for electroplating components such as door handles, signs, car bumpers, wheel covers, and anti-scratch strips.

[0047] Compared with the prior art, the present invention has the following advantages:

[0048] 1. This invention uses nickel sulfate and nickel chloride as the metal source of the plating solution, with nickel sulfate at 430 g / L and nickel chloride at 34 g / L. This can reduce the polarization phenomenon of the electrode anode, increase the conductivity of the plating solution, and make the electrode cathode have a higher current density, thereby reducing the defects formed on the surface of the plated parts after electroplating with the aluminum-like plating solution.

[0049] 2. This invention incorporates 35-45 g / L of boric acid. The addition of boric acid stabilizes the pH value of the cathode membrane, thereby stabilizing the electroplating effect. If the amount of boric acid added is too low, the plating layer becomes brittle and develops pinholes; if the amount of boric acid added is too high, the anode is prone to blockage, indirectly increasing the resistance.

[0050] 3. This invention incorporates non-fluorinated cationic surfactants and fluorinated nonionic surfactants, reducing the surface tension of the electroplating solution and solving the problems of pits and bright spots in the plating layer. Furthermore, the use of several different fluorocarbon surfactants in combination makes it easier for the emulsion droplets in the electroplating solution to be adsorbed by the adsorbent, improving the stability of the plating solution and extending its service life to 6-8 days. This has significant advantages compared to existing technologies that require filtration after 4-6 hours. The resulting plating layer has uniform brightness across the high, low, and medium color temperature zones. In addition, the fluorinated nonionic surfactants used are environmentally friendly.

[0051] 4. The plating solution prepared by this invention produces a plating layer with excellent fineness, a stronger metallic feel and an aluminum alloy-like appearance after electroplating. The plating layer also has an anti-fingerprint effect, resulting in a superior overall effect.

[0052] 5. In the electroplating process, the present invention is combined with a filtration system including a two-stage filtration unit and a dispersion unit. The two-stage filtration unit can filter out large agglomerates in the used electroplating solution and also filter out plating slag and other substances in the plating solution. The dispersion unit breaks up small agglomerates in the plating solution through turbulence and other means. Then, the plating solution is returned to the electroplating tank, which prolongs the service stability of the aluminum-like coating solution, extends the service cycle time of the plating solution, and can further improve the smoothness of the coating and the appearance of aluminum.

[0053] 6. The aluminum-like electroplating solution and electroplating process proposed in this invention have higher production efficiency, a longer-lasting sandy feel to the coating, and more stable color. The equipment and operating conditions of this process differ from those of bright nickel plating and are suitable for rack plating.

[0054] 7. The aluminum-like electroplating solution and electroplating process proposed in this invention are particularly suitable for the automotive industry and household goods. They can plate a uniform, matte, decorative nickel coating onto substrates such as steel, copper, and copper alloys. The coating surface is almost non-reflective, resistant to touch, and scratches. Furthermore, the electroplating process proposed in this invention can also be used for gold, chromium, and silver plating, making it widely applicable. Detailed Implementation

[0055] Example 1

[0056] This embodiment presents an aluminum-like electroplating solution, its electroplating process, and its application.

[0057] The raw materials for preparing the aluminum-like electroplating solution, in terms of concentration, include: nickel sulfate 430 g / L, nickel chloride 34 g / L, brightener 20 mL / L, auxiliary brightener 2 mL / L, boric acid 40 g / L, gloss modifier 0.6 mL / L, surfactant 1.6 mL / L, and deionized water.

[0058] The auxiliary brightener is a compound of sodium allyl sulfonate and sodium propargyl sulfonate, added at a concentration ratio of 10:1. The brightener is a compound of sodium o-benzoyl sulfonamide and bisbenzenesulfonamide, added at a concentration ratio of 5:1.5.

[0059] The surfactants were a mixture of non-fluorinated cationic surfactants and fluorinated cationic surfactants in a weight ratio of 1:1.1. The non-fluorinated cationic surfactants were dioctyldimethylammonium chloride and dodecyldimethylbenzylammonium chloride in a weight ratio of 1:1. The fluorinated cationic surfactants were a mixture of GS-823 fluorocarbon surfactant, GS-FC327 fluorocarbon surfactant, and TF380 fluorocarbon surfactant in a volume ratio of 1:1:1. GS-823 and GS-FC327 fluorocarbon surfactants were purchased from Lotte Chemical, and TF380 fluorocarbon surfactant was purchased from Shanghai Futian Chemical Technology Co., Ltd.

[0060] The gloss modifier is a pearl nickel sand agent, purchased from Shenzhen Leiteng Chemical Co., Ltd.

[0061] Preparation method of electroplating solution: First, the surfactant and auxiliary brightener are mixed evenly to obtain a mixture. Then, the mixture is combined with nickel sulfate, nickel chloride, brightener, boric acid and gloss modifier to prepare an aluminum-like electroplating solution.

[0062] The electroplating process conditions are as follows: process temperature 52℃, process pH 4.2, and cathode current density 4.5 A / dm³. 2 The anode current density is 1.8 A / dm³. 2 .

[0063] The electroplating process includes:

[0064] (1) Prepare an aluminum-like electroplating solution;

[0065] (2) Electroplating with aluminum-imitation electroplating solution in conjunction with a plating solution filtration system: After electroplating, the aluminum-imitation electroplating solution in the electroplating tank flows through a secondary filtration unit. The secondary filtration unit filters out large agglomerates and plating slag in the plating solution. The plating solution after passing through the secondary filtration unit flows through a dispersion unit. The dispersion unit breaks down and disperses small agglomerates in the plating solution through turbulence and other means. The plating solution after passing through the dispersion unit returns to the electroplating tank for electroplating again.

[0066] Example 2

[0067] This embodiment presents an aluminum-like electroplating solution, its electroplating process, and its application.

[0068] The raw materials for preparing the aluminum-like electroplating solution, in terms of concentration, include 430 g / L nickel sulfate, 34 g / L nickel chloride, 20 mL / L brightener, 2 mL / L auxiliary brightener, 40 g / L boric acid, 0.6 mL / L gloss modifier, 1.6 mL / L surfactant, and deionized water.

[0069] The auxiliary brightener is a compound of sodium allyl sulfonate and sodium propargyl sulfonate, with a concentration ratio of 10:1.

[0070] The brighteners sodium o-benzoylsulfonylimide and bisbenzenesulfonylimide are added in a concentration ratio of 5:1.5.

[0071] The surfactant is dioctyldimethylammonium chloride and dodecyldimethylbenzylammonium chloride in a weight ratio of 1:1.

[0072] The gloss modifier is a pearl nickel sand agent, purchased from Shenzhen Leiteng Chemical Co., Ltd.

[0073] Preparation method of electroplating solution: First, the surfactant and auxiliary brightener are mixed evenly to obtain a mixture. Then, the mixture is combined with nickel sulfate, nickel chloride, brightener, boric acid and gloss modifier to prepare an aluminum-like electroplating solution.

[0074] The electroplating process conditions are as follows: process temperature 52℃, process pH 4.2, and cathode current density 4.5 A / dm³. 2 The anode current density is 1.8 A / dm³. 2 .

[0075] The electroplating process includes:

[0076] (1) Prepare an aluminum-like electroplating solution;

[0077] (2) Electroplating with aluminum-imitation electroplating solution in conjunction with a plating solution filtration system: After electroplating, the aluminum-imitation electroplating solution in the electroplating tank flows through a secondary filtration unit. The secondary filtration unit filters out large agglomerates and plating slag in the plating solution. The plating solution after passing through the secondary filtration unit flows through a dispersion unit. The dispersion unit breaks down and disperses small agglomerates in the plating solution through turbulence and other means. The plating solution after passing through the dispersion unit returns to the electroplating tank for electroplating again.

[0078] Example 3

[0079] This embodiment presents an aluminum-like electroplating solution, its electroplating process, and its application.

[0080] The raw materials for preparing the aluminum-like electroplating solution, in terms of concentration, include: nickel sulfate 430 g / L, nickel chloride 34 g / L, brightener 20 mL / L, auxiliary brightener 2 mL / L, boric acid 40 g / L, gloss modifier 0.6 mL / L, surfactant 1.6 mL / L, and deionized water.

[0081] The auxiliary brightener is a compound of sodium allyl sulfonate and sodium propargyl sulfonate, with a concentration ratio of 10:1.

[0082] The brighteners sodium o-benzoylsulfonylimide and bisbenzenesulfonylimide are added in a concentration ratio of 5:1.5.

[0083] The surfactants were a mixture of non-fluorinated cationic surfactants and fluorinated cationic surfactants in a weight ratio of 1:1.1. The non-fluorinated cationic surfactants were dioctyldimethylammonium chloride and dodecyldimethylbenzylammonium chloride in a weight ratio of 1:1. The fluorinated cationic surfactants were a mixture of GS-823 fluorocarbon surfactant, GS-FC327 fluorocarbon surfactant, and TF380 fluorocarbon surfactant in a volume ratio of 1:1:1. GS-823 and GS-FC327 fluorocarbon surfactants were purchased from Lotte Chemical, and TF380 fluorocarbon surfactant was purchased from Shanghai Futian Chemical Technology Co., Ltd.

[0084] The gloss modifier is a pearl nickel sand agent, purchased from Shenzhen Leiteng Chemical Co., Ltd.

[0085] Preparation method of electroplating solution: First, the surfactant and auxiliary brightener are mixed evenly to obtain a mixture. Then, the mixture is combined with nickel sulfate, nickel chloride, brightener, boric acid and gloss modifier to prepare an aluminum-like electroplating solution.

[0086] The electroplating process conditions are as follows: process temperature 52℃, process pH 4.2, and cathode current density 4.5 A / dm³. 2 The anode current density is 1.8 A / dm³. 2 .

[0087] Performance testing

[0088] The aluminum-like plating solution was prepared and the electroplating process was carried out according to Examples 1-3. The door handle was then plated with an aluminum-like coating. After 5 minutes of electroplating, the plating layer was observed, and the coating was tested using a gloss enhancer. The performance results are recorded in Table 1 below.

[0089] Table 1

[0090]

Claims

1. An electroplating process, characterized in that, Includes the following steps: (1) Prepare an aluminum-like electroplating solution; (2) The aluminum-like electroplating solution is used in conjunction with the plating solution filtration system for electroplating. After electroplating, the aluminum-like electroplating solution in the electroplating tank flows through the secondary filtration unit. The secondary filtration unit filters out the large agglomerates and plating slag in the plating solution. The plating solution after passing through the secondary filtration unit flows through the dispersion unit. The dispersion unit breaks down and disperses the small agglomerates in the plating solution through turbulence. The plating solution after passing through the dispersion unit returns to the electroplating tank for electroplating again. The electroplating process conditions include: a process temperature of 52℃, a process pH of 4.2, and a cathode current density of 4.5 A / dm³. 2 The anode current density is 1.8 A / dm³. 2 ; The raw materials for preparing the aluminum-like electroplating solution, in terms of concentration, include: nickel sulfate 430 g / L, nickel chloride 34 g / L, brightener 20 mL / L, auxiliary brightener 2 mL / L, boric acid 40 g / L, gloss modifier 0.6 mL / L, surfactant 1.6 mL / L, and deionized water. The auxiliary brightener is a compound of sodium allyl sulfonate and sodium propargyl sulfonate, with a concentration ratio of 10:

1. The brightener is a compound of sodium o-benzoylsulfonylimide and bisbenzenesulfonylimide, with a concentration ratio of 5:1.

5. The surfactant is a compound of non-fluorinated cationic surfactant and fluorinated cationic surfactant in a weight ratio of 1:1.

1. The non-fluorinated cationic surfactant is dioctyldimethylammonium chloride and dodecyldimethylbenzylammonium chloride in a weight ratio of 1:

1. The fluorinated cationic surfactant is a compound of GS-823 fluorocarbon surfactant, GS-FC327 fluorocarbon surfactant and TF380 fluorocarbon surfactant in a volume ratio of 1:1:

1. The gloss modifier is pearl nickel sand; Preparation method of imitation aluminum electroplating solution: First, the surfactant and auxiliary brightener are mixed evenly to obtain a mixture. Then, the mixture is combined with nickel sulfate, nickel chloride, brightener, boric acid and gloss modifier to prepare imitation aluminum electroplating solution.

2. An application of the electroplating process according to claim 1, characterized in that, It is used in automotive parts and furniture.

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