Imidazolyl surface treatment additive, method for preparing same, and use thereof

Abstract

The present application relates to a kind of imidazole-based surface treatment additives and its preparation method and application, belong to surface treatment technical field.To solve the problem of acid copper plating bright area current density range narrow and bright agent consumption fast, the present application provides a kind of preparation method of imidazole-based surface treatment additives, sodium hydroxide, imidazole or imidazole derivative, pyridine or pyridine derivative is dissolved in deionized water, epoxy chloropropane is added to the obtained mixed system, reaction until no epoxy chloropropane suspension is observed, and imidazole-based surface treatment additive is obtained.The imidazole-based plating additive prepared in the present application is applied to acidic sulphate copper plating, which can significantly improve the brightness of copper coating in low current density area, realize the mirror surface bright in the wide current density range of 0.1-10A / dm 2 , the glossiness is maintained at 480GU or more, and the consumption rate of sulfur-containing compound main brightener can also be significantly reduced, showing excellent application potential.

Description

Technical Field

[0001] This invention belongs to the field of surface treatment technology, and particularly relates to an imidazole-based surface treatment additive, its preparation method, and its application. Background Technology

[0002] Acid sulfate copper plating is a widely used electroplating process in everyday hardware, printed circuit boards, electroforming, and other applications. It improves the conductivity of the substrate by forming a coating on its surface, enhancing its appearance, corrosion resistance, and reducing costs. During acid sulfate copper plating, the current density range in the bright zone directly affects the coating's brightness, uniformity, density, and adhesion. Within an appropriate current density range, acid sulfate copper plating can achieve a bright, smooth, and uniform coating. However, surface treatment technologies like acid sulfate copper plating suffer from an insufficiently wide current density range in the bright zone. If the current density exceeds this range, the coating's brightness will significantly decrease, and other quality problems may occur, such as a rough coating or scorching.

[0003] Meanwhile, the quality of the plating layer, electroplating efficiency, and energy consumption are all significantly affected by various additives. Acidic sulfate copper plating additives are classified into brighteners, inhibitors, and leveling agents. Brighteners can form stable complexes with copper ions, allowing for higher brightness and a more uniform deposition layer by controlling the reduction rate and deposition method of copper ions during the plating process. The most common brightener is sodium polydisulfide dipropane sulfonate (SPS), which can refine the grains and obtain a mirror-like bright plating layer. However, SPS embeds into the plating layer during electroplating, and its chemical properties are not stable enough, easily oxidizing and decomposing. Therefore, there is also the problem of rapid brightener consumption during electroplating. Summary of the Invention

[0004] To address the issues of narrow current density range and rapid brightener consumption in the bright zone of acidic copper electroplating, this invention provides an imidazole-based surface treatment additive, its preparation method, and its application.

[0005] The technical solution of the present invention:

[0006] A method for preparing an imidazole-based surface treatment additive involves dissolving sodium hydroxide, imidazole or an imidazole derivative, and pyridine or a pyridine derivative in deionized water, adding epichlorohydrin to the resulting mixture, and reacting until no epichlorohydrin suspension is observed to obtain the imidazole-based surface treatment additive. The ratio of the number of imidazole rings in the imidazole or imidazole derivative to the number of epoxy rings in the epichlorohydrin is 0.1–10:0.1–10, and the ratio of the number of imidazole rings in the imidazole or imidazole derivative to the number of pyridine rings in the pyridine or pyridine derivative is 0.1–10:0.1–10.

[0007] Furthermore, the imidazole derivative is a product in which 1 to 4 hydrogen atoms on the imidazole ring are replaced by substituents. The substituents are hydrocarbon groups, halogens, -NH2, -NHR, -NR2, -PH2, -PHR, -PR2, -OH, -SH, -OR, -SR, -SO2H, -SO3H, -CHO, -COR, -CORNH2, -COOH, -COOR, -C≡N, -N=O, -NO2, -NH-NH2, -CO(NH2), -SiR3, -B(OH)2 or N,S heterocyclic substituents, or substituents obtained by replacing hydrogen atoms or substituents in one or more of the above groups. R represents a hydrocarbon group.

[0008] Furthermore, the pyridine derivative is a product obtained by linking 1 to 5 substituents to all C and N atoms on the pyridine ring. The substituents are hydrocarbon groups, halogens, -NH2, -NHR, -NR2, -PH2, -PHR, -PR2, -OH, -SH, -OR, -SR, -SO2H, -SO3H, -CHO, -COR, -CORNH2, -COOH, -COOR, -C≡N, -N=O, -NO2, -NH-NH2, -CO(NH2), -SiR3, -B(OH)2, or N,S heterocyclic substituents, or substituents obtained by replacing a hydrogen atom or substituent in one of the above groups with one or more of the above groups. R represents hydrocarbon groups.

[0009] Furthermore, the concentration of sodium hydroxide in the mixed system is 1–100 mol / L.

[0010] An imidazole-based surface treatment additive prepared by a method for preparing an imidazole-based surface treatment additive provided by the present invention.

[0011] The application of an imidazole-based surface treatment additive provided by the present invention in electroplating or electroless plating.

[0012] Furthermore, the electroplating is acidic copper plating.

[0013] Furthermore, the acidic bright copper plating solution used in the acidic copper plating comprises the following components:

[0014] 10–1000 mg / L polyether surfactant, 5–50 mg / L sulfur-containing compound brightener, 5–100 mg / L dye leveling agent, 1–100 μL / L imidazole-based surface treatment additive of the present invention, 100–300 g / L copper sulfate pentahydrate, 50–200 g / L 98 mass% concentrated sulfuric acid and 10–300 mg / L 37 mass% concentrated hydrochloric acid.

[0015] Furthermore, the polyether surfactant is polyethylene oxide polypropylene oxide monobutyl ether, and the sulfur-containing compound main brightener is sodium polydisulfide dipropane sulfonate.

[0016] Furthermore, when using the aforementioned acidic bright copper plating solution for acidic copper electroplating, the current density in the bright zone ranges from 0.1 to 10 A / dm². 2 .

[0017] The beneficial effects of this invention are:

[0018] This invention prepares imidazole-based electroplating additives using epichlorohydrin, imidazole or its derivatives, and pyridine or its derivatives as raw materials. When applied to acidic sulfate copper plating, only an addition amount of 1–100 μL / L is required to significantly improve the brightness of the copper plating layer in low current density regions, achieving a brightness of 0.1–10 A / dm. 2 The plating layer exhibits a mirror-like shine across a wide current density range, maintaining a gloss level above 480 GU. The imidazole-based electroplating additive of this invention has a simple preparation process, requires a small amount, and can significantly reduce the consumption rate of sulfur-containing compound brighteners, demonstrating excellent application potential.

[0019] Conventional surface treatment additives require complex operations such as dropwise addition and temperature control to obtain a specific target product and avoid side reactions. However, the imidazole-based surface treatment additive preparation method provided by this invention avoids complex operations and energy consumption. It only requires directly adding three raw materials to a sodium hydroxide solution at room temperature and pressure and mixing for one minute. The preparation process of this invention is not a simple physical mixing of raw materials, but a chemical reaction. Water and imidazole or its derivatives in the reaction system can act as nucleophiles to attack the epoxy structure, resulting in a complex and diverse range of products and achieving unexpected technical effects. Attached Figure Description

[0020] Figure 1 The images show the appearance of the Hull groove specimens in Examples 1-3 and Comparative Example 1, where a corresponds to Example 1, b corresponds to Example 2, c corresponds to Example 3, and d corresponds to Comparative Example 1.

[0021] Figure 2 The figures are cyclic voltammetry curves of acidic bright copper plating solutions for Examples 1-3 and Comparative Example 1, where a corresponds to Example 1, b corresponds to Example 2, c corresponds to Example 3, and d corresponds to Comparative Example 1. Detailed Implementation

[0022] The technical solution of the present invention will be further described below with reference to embodiments, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention. In the following embodiments, the process equipment or apparatus not specifically specified are all conventional equipment or apparatus in the art. Unless otherwise specified, the raw materials used in the embodiments of the present invention are all commercially available; unless otherwise specified, the technical means used in the embodiments of the present invention are all conventional means well known to those skilled in the art.

[0023] The gloss meter used in this embodiment is an NHG60 model, purchased from Shenzhen Sanenshi Technology Co., Ltd.

[0024] The Hull cell used in the embodiment was purchased from Guangdong No. 2 Light Industry Research Institute.

[0025] The electrochemical workstation used in the examples was a CHI670 model, purchased from Shanghai Chenhua Instrument Co., Ltd.

[0026] The raw materials used in the preparation of the imidazole-based additives in the following examples were purchased from Aladdin Reagent Company.

[0027] Example 1

[0028] This embodiment provides an imidazole-based surface treatment additive and its preparation method.

[0029] The preparation steps of the imidazole-based electroplating additive in this embodiment are as follows:

[0030] Add 6.72g sodium hydroxide, 7.00g imidazole, and 12.30g nicotinic acid (pyridine-3-carboxylic acid) to 42g deionized water. After dissolving, add 17.55g epichlorohydrin and react until the epichlorohydrin suspension is no longer observable. Then, dilute to 100mL with deionized water.

[0031] The imidazole-based electroplating additive prepared in this embodiment was used in acidic bright copper plating to prepare an acidic bright copper plating solution with the following composition:

[0032] The ingredients included 800 mg / L polyethylene oxide polypropylene oxide monobutyl ether, 20 mg / L sodium didithiopropane sulfonate, 10 mg / L blue dye, 1.1 μL / L imidazole-based surface treatment additive prepared in this example, 200 g / L copper sulfate pentahydrate, 65 g / L 98 mass% concentrated sulfuric acid, and 180 mg / L 37 mass% concentrated hydrochloric acid; wherein the average molecular weight of the polyethylene oxide polypropylene oxide monobutyl ether was 1340.

[0033] Example 2

[0034] This embodiment provides an imidazole-based surface treatment additive and its preparation method.

[0035] The preparation steps of the imidazole-based electroplating additive in this embodiment are as follows:

[0036] Add 6.72g sodium hydroxide, 7.00g imidazole, and 12.30g nicotinic acid to 42g deionized water. After dissolving, add 17.55g epichlorohydrin and react until the epichlorohydrin suspension is no longer observable. Then, dilute to 100mL with deionized water.

[0037] The imidazole-based electroplating additive prepared in this embodiment was used in acidic bright copper plating to prepare an acidic bright copper plating solution with the following composition:

[0038] The ingredients included 800 mg / L polyethylene oxide polypropylene oxide monobutyl ether, 15 mg / L sodium didithiopropane sulfonate, 10 mg / L blue dye, 1.1 μL / L imidazole-based surface treatment additive prepared in this example, 200 g / L copper sulfate pentahydrate, 65 g / L 98 mass% concentrated sulfuric acid, and 180 mg / L 37 mass% concentrated hydrochloric acid; wherein the average molecular weight of the polyethylene oxide polypropylene oxide monobutyl ether was 1340.

[0039] Example 3

[0040] This embodiment provides an imidazole-based surface treatment additive and its preparation method.

[0041] The preparation steps of the imidazole-based electroplating additive in this embodiment are as follows:

[0042] Add 6.72g sodium hydroxide, 7.00g imidazole, and 12.30g nicotinic acid to 42g deionized water. After dissolving, add 17.55g epichlorohydrin and react until the epichlorohydrin suspension is no longer observable. Then, dilute to 100mL with deionized water.

[0043] The imidazole-based electroplating additive prepared in this embodiment was used in acidic bright copper plating to prepare an acidic bright copper plating solution with the following composition:

[0044] The ingredients included 800 mg / L polyethylene oxide polypropylene oxide monobutyl ether, 10 mg / L sodium didithiopropane sulfonate, 10 mg / L blue dye, 1.1 μL / L imidazole-based surface treatment additive prepared in this example, 200 g / L copper sulfate pentahydrate, 65 g / L 98 mass% concentrated sulfuric acid, and 180 mg / L 37 mass% concentrated hydrochloric acid; wherein the average molecular weight of the polyethylene oxide polypropylene oxide monobutyl ether was 1340.

[0045] Example 4

[0046] This embodiment provides an imidazole-based surface treatment additive and its preparation method.

[0047] The preparation steps of the imidazole-based electroplating additive in this embodiment are as follows:

[0048] Add 6.72g sodium hydroxide, 7.00g 4-methylimidazole, and 12.30g 5-amino-4-hydroxy-nicotinic acid to 42g deionized water. After dissolving, add 17.55g epichlorohydrin and react until the epichlorohydrin suspension is no longer observable. Then, bring the volume to 100mL with deionized water.

[0049] The imidazole-based electroplating additive prepared in this embodiment was used in acidic bright copper plating to prepare an acidic bright copper plating solution with the following composition:

[0050] The ingredients included 800 mg / L polyethylene oxide polypropylene oxide monobutyl ether, 10 mg / L sodium didithiopropane sulfonate, 10 mg / L blue dye, 1.1 μL / L imidazole-based surface treatment additive prepared in this example, 200 g / L copper sulfate pentahydrate, 65 g / L 98 mass% concentrated sulfuric acid, and 180 mg / L 37 mass% concentrated hydrochloric acid; wherein the average molecular weight of the polyethylene oxide polypropylene oxide monobutyl ether was 1340.

[0051] Example 5

[0052] This embodiment provides an imidazole-based surface treatment additive and its preparation method.

[0053] The preparation steps of the imidazole-based electroplating additive in this embodiment are as follows:

[0054] Add 6.72g sodium hydroxide, 7.00g 2-hydroxyethylimidazolium, and 12.30g 5-hydroxynicotinic acid to 42g deionized water. After dissolving, add 17.55g epichlorohydrin and react until the epichlorohydrin suspension is no longer observable. Then, dilute to 100mL with deionized water.

[0055] The imidazole-based electroplating additive prepared in this embodiment was used in acidic bright copper plating to prepare an acidic bright copper plating solution with the following composition:

[0056] The ingredients included 800 mg / L polyethylene oxide polypropylene oxide monobutyl ether, 10 mg / L sodium didithiopropane sulfonate, 10 mg / L blue dye, 1.1 μL / L imidazole-based surface treatment additive prepared in this example, 200 g / L copper sulfate pentahydrate, 65 g / L 98 mass% concentrated sulfuric acid, and 180 mg / L 37 mass% concentrated hydrochloric acid; wherein the average molecular weight of the polyethylene oxide polypropylene oxide monobutyl ether was 1340.

[0057] Example 6

[0058] This embodiment provides an imidazole-based surface treatment additive and its preparation method.

[0059] The preparation steps of the imidazole-based electroplating additive in this embodiment are as follows:

[0060] Add 6.72g sodium hydroxide, 7.00g 1H-imidazol-5-propanol, and 12.30g 1-benzylnicotinic acid to 42g deionized water. After dissolving, add 17.55g epichlorohydrin and react until the epichlorohydrin suspension is no longer observable. Then, bring the volume to 100mL with deionized water.

[0061] The imidazole-based electroplating additive prepared in this embodiment was used in acidic bright copper plating to prepare an acidic bright copper plating solution with the following composition:

[0062] The ingredients included 800 mg / L polyethylene oxide polypropylene oxide monobutyl ether, 10 mg / L sodium didithiopropane sulfonate, 10 mg / L blue dye, 1.1 μL / L imidazole-based surface treatment additive prepared in this example, 200 g / L copper sulfate pentahydrate, 65 g / L 98 mass% concentrated sulfuric acid, and 180 mg / L 37 mass% concentrated hydrochloric acid; wherein the average molecular weight of the polyethylene oxide polypropylene oxide monobutyl ether was 1340.

[0063] Comparative Example 1

[0064] This comparative example provides a method for using commercially available acidic bright copper plating additives, wherein the commercially available acidic bright copper plating additives are 210A, B, and C from a foreign company.

[0065] This comparative example prepared an acidic bright copper plating solution with the following components:

[0066] 10 mg / L 210 starter C, 0.6 mL / L 210A, 0.3 mL / L 210B, 200 g / L copper sulfate pentahydrate, 65 g / L 98 mass% concentrated sulfuric acid and 180 mg / L 37 mass% concentrated hydrochloric acid.

[0067] Experimental Example 1

[0068] Take 267 mL of each of the acidic bright copper plating solutions prepared in Examples 1-3 and Comparative Example 1, and place them in a Hull bath. Use a phosphor bronze plate as the anode and a 62# brass sheet as the cathode. Control the current to be constant at 2A and electroplating for 10 minutes. Figure 1 The images show the appearance of the test pieces in each Hull cell. The gloss of the copper plating layer was measured in areas with different current densities, and the results are shown in Table 1.

[0069] Table 1

[0070]

[0071] Depend on Figure 1 As can be seen from the appearance and gloss test data of each group of Hull cell specimens in Table 1, and the gloss levels in different current density regions, Examples 1-3 with the imidazole-based electroplating additive prepared in this invention showed better performance at 0.1 A / dm². 2The gloss level was above 480 GU, higher than that of Comparative Example 1; at 0.2 A / dm 2 The gloss level at all locations was above 630 GU, similar to or even higher than Comparative Example 1; at 1 A / dm 2 The gloss level in the above-mentioned areas consistently remained above 700 GU. This demonstrates that the acidic copper plating solution containing the imidazole-based additive prepared in this invention can improve the gloss level of the copper plating layer in low-current-density areas while ensuring high gloss in medium-to-high current-density areas.

[0072] Experimental Example 2

[0073] Take 100 mL of each of the acidic bright copper plating solutions prepared in Examples 1-3 and Comparative Example 1, and place them in beakers respectively. Cyclic voltammetry tests are performed using a rotating disk platinum electrode as the working electrode, a saturated mercury-mercurous sulfate electrode as the reference electrode, and a platinum sheet electrode as the counter electrode. The test parameters are as follows:

[0074] Potential scanning range: -0.6V to 0.25V; starting voltage: 0.25V; scanning rate: 0.02V / s; working electrode rotation speed: 1000rpm; number of scanning segments: 200.

[0075] The experimental results were taken from cycles 1, 10, 20, 40, 60, 80, and 100, and the area of ​​the copper dissolution peak was calculated. The results are as follows: Figure 2 As shown in Table 2.

[0076] Table 2

[0077]

[0078] Table 2 shows the copper dissolution peak area data of the cyclic voltammetry curves for each group of electrolytes at different cycle numbers. It can be seen that the change in copper dissolution peak area with the number of cycles in Examples 1-3 is consistently small. The copper dissolution peak area in the 100th cycle is only about 0.88%, 4.6%, and 6.4% smaller than that in the 1st cycle, respectively. In contrast, in Comparative Example 1, the copper dissolution peak area in the 10th cycle is about 34.8% smaller than that in the 1st cycle, and then gradually decreases. Although there is a slight rebound after the 80th cycle, it is still significantly lower than the peak area in the 1st cycle. The copper dissolution peak area in the 100th cycle is 44.9% smaller than that in the 1st cycle, and the decrease is still significantly greater than that in Examples 1-3. This indicates that the brightener consumption rate of the acidic copper plating solution containing the imidazole-based electrolytic additive prepared in this invention is significantly reduced.

[0079] The above embodiments, using acidic bright copper plating as an example, merely demonstrate the effectiveness of the present invention and are not intended to limit the invention. Any application of the present invention to the field of surface treatment, without departing from the principles and spirit of the invention, through adjustments or modifications, is within the protection scope of the present invention.

Claims

1. The application of an imidazole-based surface treatment additive in acidic copper electroplating, characterized in that, The method for preparing the imidazole-based surface treatment additive is as follows: dissolve sodium hydroxide, imidazole or imidazole derivative, and pyridine or pyridine derivative in deionized water; add epichlorohydrin to the resulting mixture; and react until no epichlorohydrin suspension is observed to obtain the imidazole-based surface treatment additive. The ratio of the number of imidazole rings in the imidazole or imidazole derivative to the number of epoxy rings in the epichlorohydrin is 0.1~10:0.1~10, and the ratio of the number of imidazole rings in the imidazole or imidazole derivative to the number of pyridine rings in the pyridine or pyridine derivative is 0.1~10:0.1~10.

2. The application of the imidazole-based surface treatment additive according to claim 1 in acidic copper electroplating, characterized in that, The imidazole derivative is a product in which 1 to 4 hydrogen atoms on the imidazole ring are replaced by substituents, wherein the substituents are hydrocarbon groups, halogens, -NH2, -NHR, -NR2, -PH2, -PHR, -PR2, -OH, -SH, -OR, -SR, -SO2H, -SO3H, -CHO, -COR, -CORNH2, -COOH, -COOR, -C≡N, -N=O, -NO2, -NH-NH2, -CO(NH2), -SiR3, -B(OH)2 or N,S heterocyclic substituents, where R represents a hydrocarbon group.

3. The application of the imidazole-based surface treatment additive according to claim 1 or 2 in acidic copper electroplating, characterized in that, The pyridine derivative is a product obtained by linking 1 to 5 substituents to all C and N atoms on the pyridine ring. The substituents are hydrocarbon groups, halogens, -NH2, -NHR, -NR2, -PH2, -PHR, -PR2, -OH, -SH, -OR, -SR, -SO2H, -SO3H, -CHO, -COR, -CORNH2, -COOH, -COOR, -C≡N, -N=O, -NO2, -NH-NH2, -CO(NH2), -SiR3, -B(OH)2, or N and S heterocyclic substituents, where R represents a hydrocarbon group.

4. The application of the imidazole-based surface treatment additive according to claim 3 in acidic copper electroplating, characterized in that, The concentration of sodium hydroxide in the mixture is 1~100 mol / L.

5. The application of the imidazole-based surface treatment additive according to claim 4 in acidic copper electroplating, characterized in that, The acidic bright copper plating solution used in the acidic electroplating of copper comprises the following components: 10–1000 mg / L polyether surfactant, 5–50 mg / L sulfur-containing compound main brightener, 5–100 mg / L dye leveling agent, 1–100 μL / L imidazole-based surface treatment additive, 100–300 g / L copper sulfate pentahydrate, 50–200 g / L 98 mass% concentrated sulfuric acid, and 10–300 mg / L 37 mass% concentrated hydrochloric acid.

6. The application of the imidazole-based surface treatment additive according to claim 5 in acidic copper electroplating, characterized in that, The polyether surfactant is polyethylene oxide polypropylene oxide monobutyl ether, and the sulfur-containing compound main brightener is sodium didithiopropane sulfonate.

7. The application of the imidazole-based surface treatment additive according to claim 6 in acidic copper electroplating, characterized in that, When performing acidic copper plating using the aforementioned acidic bright copper plating solution, the current density in the bright zone ranges from 0.1 to 10 A / dm². 2 .

Images