A methanesulfonic acid high-speed tin plating solution for high-speed tin plating and its preparation method

Abstract

The present invention relates to a tin-plating solution, in particular to a methanesulfonic acid high-speed tin-plating solution for high-speed tin-plating and a preparation method thereof, comprising the following components: 10-100 ml / L of a 70 wt% methanesulfonic acid aqueous solution, 50-150 ml / L of stannous methanesulfonate, 5-50 ml / L of an antioxidant, 1-50 ml / L of a grain refiner, 0.1-20 μl / L of a defoamer, and 0.1-10 ml / L of sulfuric acid. The tin-plating solution provided by the present invention has the characteristics of high oxidation resistance, high polarization ability, high dispersibility, high stability and low foaming, can meet the production requirements of a 500 m / min belt speed high-speed tin-plating production unit, and can be used for extremely low tin amounts (≈0.5 g·m ‑2 ) In the production of tinplate, the tin-plating liquid can be ensured to be used stably under the condition of less than 70°C, which is green and environmentally friendly, has low toxicity, and is easy to treat wastewater, which can save the cost of sewage treatment for production enterprises.

Description

Technical Field

[0001] The invention relates to a tin plating solution, in particular to a methanesulfonic acid high-speed tin plating solution for high-speed tin plating and a preparation method thereof. Background Art

[0002] One of the main uses of tin plating is as a protective coating for steel plates. At the same time, because tin ions and their compounds are harmless to the human body, and the tin plating has good corrosion resistance, ductility and weldability, tin-plated steel plates are also widely used in food processing, packaging, holding and shipping, such as canned packaging.

[0003] At present, there are more than 30 electroplated tin plate production lines in China. In the continuous and high-speed electroplated tin steel plate production system, the acidic tin plating methods used in industry mainly include phenol sulfonate system, sulfate system and methane sulfonate system. In China, after Baosteel Meishan Iron and Steel Company built the first 200,000-ton insoluble anode high-speed methane sulfonic acid (MSA) tin plating production line in China in 2009 and successfully put it into production, Shougang Jingtang, Shagang Co., Ltd., Zhongyue Posco and Kema and other manufacturers have successively adopted the methane sulfonic acid tin plating system. The methane sulfonic acid electroplating tin system has many technical advantages such as non-toxic and stable plating solution, complete degradation under natural conditions, simple wastewater treatment, high current efficiency, strong dispersion ability, wide current density range, and small amount of tin mud. Therefore, methane sulfonic acid tin plating has been greatly developed as a substitute for other tin plating methods and is currently widely used in industrial production at home and abroad.

[0004] However, with the extensive application of tin and the continuous exploitation of tin resources, the global tin reserves are gradually decreasing, and the chromium value of tin is also rising. In order to further reduce costs and increase competitiveness with packaging materials such as glass and aluminum plates, the thinning of the tin coating is an inevitable development trend, which can reduce energy loss and reduce corporate costs. The tin coating amount of early tinplate was 10g·m -2 The tin content of the commonly used low-tin tin-plated plate is 1.1g·m -2 , and 0.5 g·m -2 Tin-plated sheets with a low tin-plating amount are also under development. As the tin-plating amount decreases, the problems of low tin-plating efficiency and uneven tin-plating have a more serious impact on the performance of tin-plated sheets. In addition, when the tin-plating production line uses an insoluble anode system, a large amount of oxygen will be released from the anode during the tin-plating process. The released oxygen will have a certain impact on the stability of the plating solution and accelerate the Sn in the tin-plating solution. 2+ Oxidized to Sn 4+ , and eventually insoluble tin mud precipitation is generated, which accelerates the consumption of stannous ions in the plating solution. Therefore, in order to meet the requirements of the electroplating tin steel plate production line for high current and high speed tinning, the tin plating solution needs to meet the requirements of high oxidation resistance, high polarization ability, high dispersibility, high stability and low foaming, which puts higher requirements on the tin plating solution additives.

[0005] At present, the domestic high-speed electroplating tin production lines mainly include tin-plating units produced by SMS Germany and Nippon Steel Corporation of Japan. The high-speed electroplating unit developed by SMS Germany has a maximum belt speed of 600m / min, and the tin-plating production line of Nippon Steel Corporation of Japan has a belt speed of 450m / min. Since the tin-plating units currently used in steel mills are fast and the thickness of the current tin plating layer is very thin, the methanesulfonic acid system tin-plating additives that can meet the requirements mainly come from Dow Chemical and Quaker Chemical. However, after the domestic market of Dow Chemical's methanesulfonic acid system tin-plating additives was acquired by Quaker Chemical in 2021, the domestic methanesulfonic acid system tin-plating additives were exclusively monopolized by Quaker Chemical. Currently, only the G8 methanesulfonic acid (MSA) tin-plating additive developed by Quaker Chemical can meet the requirements of 500m / min belt speed high-speed tin-plating production units. Therefore, it is particularly urgent to develop methanesulfonic acid high-speed tin-plating liquid additives with independent intellectual property rights.

[0006] Chinese patent CN102418123A discloses a high-speed electroplating bright tin plating solution and its preparation method and application. The bright tin plating solution disclosed in the patent contains 120-200ml of tin methanesulfonate, 100-175ml of 70wt% methanesulfonic acid, 0.03-5g of brightener, 30-45g of conductive salt, 1-10g of grain refiner, 5-20g of antioxidant, 0.5-2g of wetting agent and 0.0005-0.001g of anti-foaming agent per liter of plating solution. Although the bright tin plating solution has excellent coating rate, dispersibility and anti-foaming ability, and can be used in high-speed electroplating process, the antioxidant used in the process is a mixture of toluenesulfonamide and o-sulfonylbenzene imide, which cannot effectively inhibit the Sn in the methanesulfonic acid tin plating solution. 2+ Oxidized to Sn 4+ , resulting in poor stability of the high-speed tin plating solution. In addition, the use temperature of the high-speed tin plating solution is 14-37°C, and the optimal use temperature is 25°C, which cannot meet the needs of the current tin plating production line.

[0007] Chinese patent CN103882484A discloses a high-speed electrotin plating solution, which includes the following ingredients: 5-100 / L tin methanesulfonate, 10-100ml / L methanesulfonic acid, 0.1-200ml / L sulfuric acid, 0.1-200mg / L defoamer, 0.1-50g / L fine crystal agent, 0.01-20g / L moving agent, 0.1-40g / L antioxidant. Although the invention meets the requirements of high-speed tin plating production line to a certain extent, the dispersibility of the plating solution cannot meet the requirements of extremely low tin plating amount (≥0.5g·m -2 )Tinplate production. Summary of the invention

[0008] The present invention aims to provide a methanesulfonic acid high-speed tin plating solution for high-speed tin plating and a preparation method thereof. The methanesulfonic acid high-speed tin plating solution has high oxidation resistance, high polarization ability, high dispersibility, high stability and low foaming, can meet the production requirements of a 500m / min belt speed high-speed tin plating production unit, and can be used for extremely low tin content (≈0.5g·m -2 )In the production of tinplate.

[0009] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0010] A methanesulfonic acid high-speed tin plating solution for high-speed tin plating comprises the following components: 10-100 ml / L of 70wt% methanesulfonic acid aqueous solution, 50-150 ml / L of stannous methanesulfonate, 5-50 ml / L of antioxidant, 1-50 ml / L of grain refiner, 0.1-20 μl / L of defoamer and 0.1-10 ml / L of sulfuric acid.

[0011] Among them, the stannous methanesulfonate solution has the chemical formula (CH3SO3)2Sn.

[0012] Furthermore, the antioxidant is a mixture of two or more of catechol, hydroquinone, resorcinol, p-hydroxyanisole, tert-butylhydroquinone, ascorbic acid and β-naphthol.

[0013] Furthermore, the antioxidant is a mixture of p-hydroxyanisole and hydroquinone in a mass ratio of 10-15:1, and the balance is deionized water.

[0014] Further, the grain refiner comprises the following components: 1-5 g / L of block polyether A, 10-30 g / L of block polyether B, and the balance is deionized water;

[0015] The block polyether A is one of propylene glycol polyoxyethylene polyoxypropylene ether (multiple molecular weights), glycerol polyoxyethylene polyoxypropylene ether, butyl alcohol polyoxyethylene-polyoxypropylene ether, lauryl alcohol polyoxyethylene polyoxypropylene ether, octylphenol polyoxyethylene polyoxypropylene ether, octadecyl alcohol polyoxyethylene polyoxypropylene ether and allyl alcohol polyoxyethylene polyoxypropylene ether;

[0016] The block polyether B is one of propylene glycol polyoxyethylene polyoxypropylene ether (multiple molecular weights), glycerol polyoxyethylene polyoxypropylene ether butyl, alcohol polyoxyethylene polyoxypropylene ether, lauryl alcohol polyoxyethylene polyoxypropylene ether, octylphenol polyoxyethylene polyoxypropylene ether, octadecyl alcohol polyoxyethylene polyoxypropylene ether and allyl alcohol polyoxyethylene polyoxypropylene ether.

[0017] Furthermore, the molecular weight of the block polyether A is 900-1700, the viscosity is 180-250 CPS at 25° C., the hydrophilic-lipophilic balance value is 2-10, and the addition amount is 1-5 g / L.

[0018] Furthermore, the block polyether A is one of propylene glycol polyoxyethylene polyoxypropylene ether L31, L35, F38, L42, L43, L44, L45, L61, L62, L63, L64, P65, F68, and P84.

[0019] Furthermore, the molecular weight of the block polyether B is 2500-3100, the viscosity is 400-560 CPS at 25° C., the hydrophilic-lipophilic balance value is 6-14, and the addition amount is 10-30 g / L.

[0020] Furthermore, the block polyether B is one of propylene glycol polyoxyethylene polyoxypropylene ether L31, L35, F38, L42, L43, L44, L45, L61, L62, L63, L64, P65, F68, and P84.

[0021] Furthermore, the defoaming agent comprises the following components: 200-500 g / L of polypropylene glycol and 500-800 g / L of polyether polyol C; the polypropylene glycol is one of PPG-400, PPG-600, PPG-800, PPG-1000, PPG-1500, PPG-2000 and PPG-3000; the polyether polyol C is one of polyether polyol 230, polyether polyol 330 and polyether polyol 330N, and has a molecular weight of 2500-5500 and a hydroxyl value of 30-60 mgKOH / g.

[0022] The present invention also provides a method for preparing the methanesulfonic acid high-speed tin plating solution for high-speed tin plating, comprising the following steps:

[0023] S1. Add deionized water into the plating tank, add 70 wt % methanesulfonic acid aqueous solution under stirring, and stir evenly;

[0024] S2, then add stannous methanesulfonate and stir evenly;

[0025] S3, then add antioxidant and stir evenly; then add grain refiner and sulfuric acid and stir evenly;

[0026] S4. Finally, add the defoamer using the ethanol transfer method and stir until the solution is uniform.

[0027] The beneficial effects of the present invention are as follows:

[0028] 1. The surfactant used in the methanesulfonic acid high-speed tin plating solution provided by the present invention is a polyether type non-ionic surfactant, and does not contain other anionic, cationic and amphoteric surfactants, thereby effectively improving the stability of the tin plating solution during use.

[0029] 2. The methanesulfonic acid high-speed tin-plating solution provided by the present invention can effectively improve the cathodic polarization ability of the plating solution, and can obtain a crystalline and finely coated layer. The tin-plating solution has high oxidation resistance, high polarization ability, high dispersibility, high stability and low foaming, and can meet the production requirements of a 500m / min belt speed high-speed tin-plating production unit, and can be used for extremely low tin content (≈0.5g·m -2 )In the production of tinplate.

[0030] 3. The cloud point of the methanesulfonic acid high-speed tin plating solution provided by the present invention is greater than 70°C, which can ensure that the tin plating solution can be stably used under the condition of less than 70°C.

[0031] 4. The methanesulfonic acid high-speed tin plating solution provided by the present invention can be completely degraded under natural conditions, is green and environmentally friendly, has low toxicity, and is easy to treat wastewater, which can save the cost of sewage treatment for production enterprises. DETAILED DESCRIPTION

[0032] The embodiments of the present invention are described in further detail below.

[0033] The invention discloses a methanesulfonic acid high-speed tin plating solution for high-speed tin plating and a preparation method thereof.

[0034] The methanesulfonic acid high-speed tin plating solution is composed of the following components: 10-100 ml / L of 70 wt% methanesulfonic acid aqueous solution, 50-150 ml / L of stannous methanesulfonate, 5-50 ml / L of antioxidant, 1-50 ml / L of grain refiner, 0.1-20 μl / L of defoamer, and 0.1-10 ml / L of sulfuric acid. The preparation method comprises the following steps:

[0035] S1. Add a certain amount of deionized water into the plating tank, add methanesulfonic acid aqueous solution under uniform stirring, and stir evenly;

[0036] S2, adding stannous methanesulfonate to the above solution and stirring evenly;

[0037] S3, then add antioxidant and stir evenly; then add grain refiner and sulfuric acid and stir evenly;

[0038] S4. Finally, add the defoamer using the ethanol transfer method and stir for 20 minutes until the solution is uniform.

[0039] The antioxidant is a mixture of two or more of catechol, hydroquinone, resorcinol, p-hydroxyanisole, tert-butylhydroquinone, ascorbic acid and beta-naphthol; the antioxidant is a mixture of p-hydroxyanisole and hydroquinone in a mass ratio of 10-15:1, and the balance is deionized water.

[0040] The grain refiner comprises the following components: 1-5 g / L of block polyether A, 10-30 g / L of block polyether B, and the balance is deionized water; the block polyether A is one of propylene glycol polyoxyethylene polyoxypropylene ether, glycerol polyoxyethylene polyoxypropylene ether, butanol polyoxyethylene-polyoxypropylene ether, lauryl alcohol polyoxyethylene polyoxypropylene ether, octylphenol polyoxyethylene polyoxypropylene ether, octadecyl alcohol polyoxyethylene polyoxypropylene ether and allyl alcohol polyoxyethylene polyoxypropylene ether; the block polyether A is one of propylene glycol polyoxyethylene polyoxypropylene ether L31, L35, F38, L42, L43, L44, L45, L61, L62, L63, L64, P65, F68, and P84. The molecular weight of the block polyether A is 900-1700, the viscosity is 180-250 CPS at 25° C., the hydrophilic-lipophilic balance value is 2-10, and the addition amount is 1-5 g / L.

[0041] The block polyether B is one of propylene glycol polyoxyethylene polyoxypropylene ether, glycerol polyoxyethylene polyoxypropylene ether butyl, alcohol polyoxyethylene polyoxypropylene ether, lauryl alcohol polyoxyethylene polyoxypropylene ether, octylphenol polyoxyethylene polyoxypropylene ether, octadecyl alcohol polyoxyethylene polyoxypropylene ether and allyl alcohol polyoxyethylene polyoxypropylene ether. The block polyether B is one of propylene glycol polyoxyethylene polyoxypropylene ether L31, L35, F38, L42, L43, L44, L45, L61, L62, L63, L64, P65, F68, and P84. The block polyether B has a molecular weight of 2500-3100, a viscosity of 400-560 CPS at 25° C., a hydrophilic-lipophilic balance of 6-14, and an addition amount of 10-30 g / L.

[0042] The defoaming agent comprises the following components: 200-500 g / L of polypropylene glycol and 500-800 g / L of polyether polyol C; the polypropylene glycol is one of PPG-400, PPG-600, PPG-800, PPG-1000, PPG-1500, PPG-2000 and PPG-3000; the polyether polyol C is one of polyether polyol 230, polyether polyol 330 and polyether polyol 330N, and has a molecular weight of 2500-5500 and a hydroxyl value of 30-60 mgKOH / g.

[0043] Example 1

[0044]

[0045] The antioxidant is a mixture of p-hydroxyanisole and hydroquinone in a mass ratio of 11:1, and the content of hydroquinone is 4 g / L.

[0046] The grain refiner is a mixture of propylene glycol polyoxyethylene polyoxypropylene ether A and propylene glycol polyoxyethylene polyoxypropylene ether B in a mass ratio of 1:7; the propylene glycol polyoxyethylene polyoxypropylene ether A has an average molecular weight of 1100 (L31) and a content of 3g / l; the propylene glycol polyoxyethylene polyoxypropylene ether B has an average molecular weight of 2900 (L64).

[0047] The defoamer is a mixture of polypropylene glycol and polyether polyol C in a mass ratio of 1:1.5; the average molecular weight of the polypropylene glycol is 1500 and the usage amount is 400g / l; the average molecular weight of the polyether polyol C (330N) is 5000 and the hydroxyl value is 33-37mgKOH / g.

[0048] The method for preparing the methanesulfonic acid high-speed tin plating solution comprises the following preparation method:

[0049] S1. Add a certain amount of deionized water into the plating tank, add methanesulfonic acid aqueous solution under uniform stirring, and stir evenly;

[0050] S2, adding stannous methanesulfonate to the above solution and stirring evenly;

[0051] S3, then add antioxidant and stir evenly; then add grain refiner and sulfuric acid and stir evenly;

[0052] S4. Finally, add the defoamer using the ethanol transfer method and stir for 20 minutes until the solution is uniform.

[0053] Example 2

[0054]

[0055] The antioxidant is a mixture of p-hydroxyanisole and hydroquinone in a mass ratio of 11:1, and the content of hydroquinone is 3 g / L.

[0056] The grain refiner is a mixture of propylene glycol polyoxyethylene polyoxypropylene ether A and propylene glycol polyoxyethylene polyoxypropylene ether B in a mass ratio of 1:7; the propylene glycol polyoxyethylene polyoxypropylene ether A has an average molecular weight of 1600 (L42) and a content of 3g / l; the propylene glycol polyoxyethylene polyoxypropylene ether B has an average molecular weight of 2900 (L64).

[0057] The defoamer is a mixture of polypropylene glycol and polyether polyol C in a mass ratio of 1:1.5; the average molecular weight of the polypropylene glycol is 1500 and the usage amount is 400g / l; the average molecular weight of the polyether polyol C (330) is 3000 and the hydroxyl value is 53-59mgKOH / g.

[0058] Example 3

[0059]

[0060]

[0061] The antioxidant is a mixture of p-hydroxyanisole and hydroquinone in a mass ratio of 11:1, and the content of hydroquinone is 4 g / L.

[0062] The grain refiner is a mixture of propylene glycol polyoxyethylene polyoxypropylene ether A and propylene glycol polyoxyethylene polyoxypropylene ether B in a mass ratio of 1:7; the propylene glycol polyoxyethylene polyoxypropylene ether A has an average molecular weight of 1100 (L31) and a content of 2g / l; the propylene glycol polyoxyethylene polyoxypropylene ether B has an average molecular weight of 2500 (L62).

[0063] The defoamer is a mixture of polypropylene glycol and polyether polyol C in a mass ratio of 1:1.5; the average molecular weight of the polypropylene glycol is 1000, and the usage amount is 400g / l; the average molecular weight of the polyether polyol C (330N) is 5000, and the hydroxyl value is 33-37mgKOH / g.

[0064] Example 4

[0065]

[0066] The antioxidant is a mixture of p-hydroxyanisole and hydroquinone in a mass ratio of 11:1, and the content of hydroquinone is 3 g / L.

[0067] The grain refiner is a mixture of propylene glycol polyoxyethylene polyoxypropylene ether A and propylene glycol polyoxyethylene polyoxypropylene ether B in a mass ratio of 1:7; the propylene glycol polyoxyethylene polyoxypropylene ether A has an average molecular weight of 1100 (L31) and a content of 3g / l; the propylene glycol polyoxyethylene polyoxypropylene ether B has an average molecular weight of 2900 (L64).

[0068] The defoamer is a mixture of polypropylene glycol and polyether polyol C in a mass ratio of 1:1.5; the average molecular weight of the polypropylene glycol is 1500 and the usage amount is 400g / l; the average molecular weight of the polyether polyol C (330) is 3000 and the hydroxyl value is 53-59mgKOH / g.

[0069] Example 5

[0070]

[0071] The antioxidant is a mixture of p-hydroxyanisole and hydroquinone in a mass ratio of 10:1, and the content of hydroquinone is 4 g / L.

[0072] The grain refiner is a mixture of propylene glycol polyoxyethylene polyoxypropylene ether A and propylene glycol polyoxyethylene polyoxypropylene ether B in a mass ratio of 1:10; the propylene glycol polyoxyethylene polyoxypropylene ether A has an average molecular weight of 1100 (L31) and a content of 3g / l; the propylene glycol polyoxyethylene polyoxypropylene ether B has an average molecular weight of 2900 (L64).

[0073] The defoamer is a mixture of polypropylene glycol and polyether polyol C in a mass ratio of 1:1; the average molecular weight of the polypropylene glycol is 1500, and the usage amount is 500g / l; the average molecular weight of the polyether polyol C (330N) is 5000, and the hydroxyl value is 33-37mgKOH / g.

[0074] Example 6

[0075]

[0076]

[0077] The antioxidant is a mixture of p-hydroxyanisole and hydroquinone in a mass ratio of 15:1, and the content of hydroquinone is 3 g / L.

[0078] The grain refiner is a mixture of propylene glycol polyoxyethylene polyoxypropylene ether A and propylene glycol polyoxyethylene polyoxypropylene ether B in a mass ratio of 1:5; the propylene glycol polyoxyethylene polyoxypropylene ether A has an average molecular weight of 1600 (L42) and a content of 5 g / l; the propylene glycol polyoxyethylene polyoxypropylene ether B has an average molecular weight of 2900 (L64).

[0079] The defoamer is a mixture of polypropylene glycol and polyether polyol C in a mass ratio of 1:4; the average molecular weight of the polypropylene glycol is 1500 and the usage amount is 200g / l; the average molecular weight of the polyether polyol C (330) is 3000 and the hydroxyl value is 53-59mgKOH / g.

[0080] Comparative Example 1

[0081] A foreign Ronastan series tin plating additive product is used as comparative example 1. The composition of the tin plating solution of the foreign Ronastan series tin plating additive is as follows:

[0082]

[0083] Comparative Example 2

[0084] A tinning solution, comprising the following components:

[0085]

[0086]

[0087] The preparation method includes the following preparation method:

[0088] S1. Add a certain amount of deionized water into the plating tank, add methanesulfonic acid aqueous solution under uniform stirring, and stir evenly;

[0089] S2, adding stannous methanesulfonate to the above solution and stirring evenly;

[0090] S3. Then add antioxidant and stir evenly; then add sulfuric acid and stir evenly.

[0091] The wetting performance test of the tin plating solution obtained in Example 1-11 and Comparative Example 1-2 was carried out:

[0092] The wetting performance of the plating solution is related to the wetting of the plating surface and the initial deposition of the tin layer, and is one of the important indicators of high-speed electroplating. The plating solution wetting performance test is carried out using a Kocour viscosity tube (Kocour, Model 075920), and the number of drops of 5mL plating solution is measured at 25°C. Before and after each test, it is rinsed with deionized water, calibrated with 5mL water, and the number of drops is 39.

[0093] Plating solution dispersion ability test:

[0094] The dispersibility of the plating solution refers to the ability of the plating solution to evenly distribute the thickness of the coating on the surface of the workpiece under specific conditions. The results of the step-by-step distribution of the coating relative to the primary current after the plating solution uses additives are examined. There are two methods for testing the dispersibility of the plating solution: the near-far cathode method and the bent cathode method. The near-far cathode method used in this test is that in the Haring trough, two brass sheets of the same size are used as cathodes (not sealed on the working surface), and a mesh anode of the same size as the cathode is placed between the two cathodes, and the two cathodes are at different distances from the anode. Generally, the distance between the far cathode and the anode and the distance between the near cathode and the anode are in the ratio of 5:1 (K=5) or 2:1 (K=2). After a period of electroplating, weigh the mass of the deposited metal on the far cathode and the near cathode, and substitute it into the formula to calculate the dispersibility of the electrolyte. In this experiment, the distance between the far and near cathode and the anode is set to 2:1, that is, K=2, at 45°C, 2A / dm 2 After electroplating for 5 minutes under the conditions of , take out the cathode brass sheet, weigh the increment of deposited metal on the far and near cathodes, and calculate the dispersion capacity of the plating solution. The calculation formula is shown in (1).

[0095]

[0096] T——dispersion capacity, %;

[0097] K——the distance between the cathode and the anode;

[0098] D near - the mass of metal deposited near the cathode;

[0099] D far - the mass of metal deposited on the far cathode;

[0100] Plating solution cloud point test:

[0101] Nonionic surfactants can form hydrogen bonds with water in aqueous solution. When the temperature of the solution is raised to a certain point, the hydrogen bonds break, the nonionic surfactant separates from the water phase, and the solution changes from clear to turbid. This temperature point is called the turbidity point. When the working temperature of the plating solution exceeds its turbidity point, the additives in the plating solution will lose their effect. Therefore, the turbidity point is an important parameter for examining the maximum working temperature limit of the additives in the plating solution. The test method is to add a certain concentration of additives to a test tube, insert a thermometer, and gradually increase the temperature in a water bath. When the solution changes from clear to turbid, this temperature is the turbidity point. In the experiment, take a 50mL test tube, add 2mL of plating solution and dilute it with water to the scale, place it in a water bath and continue to heat it, and record the temperature at which the solution changes from clear to turbid, which is the turbidity point.

[0102] Table 1 Examples and test results of plating bath performance

[0103]

[0104]

[0105] Note: In Comparative Example 2, no surfactants containing polyether substances such as grain refiners and defoamers were added, and the plating solution cloud point test was not performed.

[0106] It can be seen from the test results in Table 1 that compared with the Ronastan tin plating additive product from China in Comparative Example 1, the methanesulfonic acid high-speed tin plating solution provided by the present invention has excellent plating solution wettability, dispersibility and high turbidity point, and a wide operating temperature range; the plating solution has excellent dispersibility and can meet the requirements of extremely low tin content (≈0.5g·m -2 ) The production requirements of tinplate can save tin resources and reduce production costs.

[0107] The methanesulfonic acid high-speed tin plating solution provided by the invention can effectively improve the cathode polarization ability of the plating solution, and can obtain a crystallized and finely plated layer. The plating solution has high oxidation resistance, high polarization ability, high dispersibility, high stability and low foaming, and can meet the production requirements of a 500m / min belt speed high-speed tin plating production unit.

Claims

1. A methanesulfonic acid high-speed tin plating solution for high-speed tin plating, characterized in that: The invention comprises the following ingredients: 10-100 ml / L of 70 wt% methanesulfonic acid aqueous solution, 50-150 ml / L of stannous methanesulfonate, 5-50 ml / L of antioxidant, 1-50 ml / L of grain refiner, 0.1-20 μl / L of defoamer, and 0.1-10 ml / L of sulfuric acid; The grain refiner comprises the following components: 1-5 g / L of block polyether A, 10-30 g / L of block polyether B, and the balance is deionized water; The block polyether A is one of propylene glycol polyoxyethylene polyoxypropylene ether L31, L35, F38, L42, L43, L44, L45, L61, L62, L63, L64, P65, F68, and P84; the molecular weight of the block polyether A is 900-1700; The block polyether B is one of propylene glycol polyoxyethylene polyoxypropylene ether L31, L35, F38, L42, L43, L44, L45, L61, L62, L63, L64, P65, F68, and P84; The defoamer comprises 200-500 g / L of polypropylene glycol and 500-800 g / L of polyether polyol C; the molecular weight of the block polyether B is 2500-3100; The antioxidant is a mixture of p-hydroxyanisole and hydroquinone in a mass ratio of 10-15:1, and the balance is deionized water.

2. The methanesulfonic acid high-speed tin plating solution for high-speed tin plating according to claim 1, characterized in that: The block polyether A has a viscosity of 180-250 CPS at 25° C. and a hydrophilic-lipophilic balance value of 2-10.

3. The methanesulfonic acid high-speed tin plating solution for high-speed tin plating according to claim 1, characterized in that: The block polyether B has a viscosity of 400-560 CPS at 25° C. and a hydrophilic-lipophilic balance value of 6-14.

4. The methanesulfonic acid high-speed tin plating solution for high-speed tin plating according to claim 1, characterized in that: The polypropylene glycol is one of PPG-400, PPG-600, PPG-800, PPG-1000, PPG-1500, PPG-2000 and PPG-3000; The polyether polyol C is one of polyether polyol 230, polyether polyol 330 and polyether polyol 330N, and has a molecular weight of 2500-5500 and a hydroxyl value of 30-60 mgKOH / g.

5. A method for preparing a methanesulfonic acid high-speed tin plating solution for high-speed tin plating according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Add deionized water into the plating tank, add 70 wt % methanesulfonic acid aqueous solution under stirring, and stir evenly; S2, then add stannous methanesulfonate and stir evenly; S3, then add antioxidant and stir evenly; then add grain refiner and sulfuric acid and stir evenly; S4. Finally, add the defoamer using the ethanol transfer method and stir until the solution is uniform.

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