Method for rapidly preparing stannous methanesulfonate

Abstract

The invention relates to a method for rapidly preparing stannous methanesulfonate, which comprises the following steps of: reacting tin with a methanesulfonic acid solution for a period of time in microwave heating, cooling, crystallizing, filtering, washing and drying to obtain a stannous methanesulfonate product, the molar ratio of tin to methanesulfonic acid is 1: (2-6), the microwave power is 500-1500 W, the reaction temperature is 120-150 DEG C, and the reaction time is 1-2 hours. Compared with the problems of high-temperature decomposition and unstable yield caused by temperature difference inside and outside a reactor in traditional oil bath heating, infrared and microwave are combined, the reaction temperature can be accurately controlled through infrared temperature control, decomposition of stannous methanesulfonate caused by too high temperature is avoided, then the effect of directly aggravating molecular movement on reactant molecules through microwaves, and the yield of stannous methanesulfonate is improved. The method has the advantages that the reaction is accelerated obviously, the stannous methanesulfonate can be quickly prepared within 1-2 hours by the aid of limitation of preparation parameters, and the yield is stabilized at 84.1%-92.4%.

Description

Technical Field

[0001] The invention belongs to the field of stannous methanesulfonate preparation, and particularly relates to a method for rapidly preparing stannous methanesulfonate. Background Art

[0002] With the rapid development of electroplating and electronic industries, people have higher and higher requirements for electroplating solutions, and more and more aspects need to be paid attention to, such as the safety, stability, and environmental protection of electroplating solutions. The electroplating solution with stannous methanesulfonate as the main salt has the advantages of stable solution, low toxicity, low corrosion, low foaming, and high coating quality, and is mainly used in the tinning process of electronic components.

[0003] At present, the preparation process of stannous methanesulfonate is mainly obtained by substitution reaction between tin and methanesulfonic acid. CN1657520A discloses a method for preparing stannous methanesulfonate by tin powder, wherein the tin powder and methanesulfonic acid are subjected to substitution reaction for 3 to 5 hours, the reaction solution is filtered, crystallized, and washed to obtain stannous methanesulfonate crystals, and then the crystals are configured to obtain products of different concentrations. Li Liqing disclosed the study of the synthesis process of stannous methanesulfonate, which studied the influence of experimental conditions on the yield of stannous methanesulfonate. Methanesulfonic acid and tin particles are heated to 140°C in an oil bath and reacted for about 5.5 hours. When the tin particles in the three-necked flask are completely dissolved, the reaction is completed. During the reaction, an electric stirrer is used to stir, and then the reaction solution is cooled and crystallized, filtered, and the filtrate is recovered. The filter cake is washed with anhydrous ether (the washing liquid can be separated from ether and methanesulfonic acid by distillation at 40°C, and the washing liquid can be recovered and used again), and then the product is vacuum dried to obtain a white solid product. The results show that the process has a simple synthesis route, a white solid product, a high yield, and a high purity. The optimal process is a temperature of 140°C, a reaction time of 5.5 hours, and preferably a tin particle with a diameter of 3 mm. However, the current preparation methods have a relatively long reaction time. Summary of the invention

[0004] The purpose of the present invention is to solve the above technical problems and provide a simple, fast and easy-to-control method for preparing stannous methanesulfonate.

[0005] To achieve the above-mentioned purpose, the technical solution of the present invention is: A method for rapidly preparing stannous methanesulfonate is to react tin with a methanesulfonic acid solution in microwave heating for a period of time, and then cool and crystallize, filter, wash and dry to obtain a stannous methanesulfonate product; the molar ratio of tin to methanesulfonic acid is 1: (2-8), the microwave power is 500W-1500W, the reaction temperature is 120°C-150°C, and the reaction time is 1-2 hours. The filtrate obtained by filtration is a methanesulfonic acid solution, which can be circulated to a microwave reactor for continued use.

[0006] The reaction principle of the present invention is:

[0007] As a further technical solution, the tin mentioned above is tin flower or tin powder.

[0008] As a further technical solution, the mass concentration of the above-mentioned methanesulfonic acid solution is 70% to 98%.

[0009] As a further technical solution, the molar ratio of tin to methanesulfonic acid is 1:4, the microwave power is 1500 W, the reaction temperature is 140° C., the reaction time is 2 hours, and the mass concentration of the methanesulfonic acid solution is 70%.

[0010] As a further technical solution, the above-mentioned cooling crystallization is to naturally cool the reaction product to 40°C to 50°C.

[0011] As a further technical solution, the above washing is performed using anhydrous ethanol.

[0012] As a further technical solution, the microwave reactor for the tin and methanesulfonic acid solution is made of SiC material and is equipped with an infrared temperature measurement system.

[0013] As a further technical solution, the above stannous methanesulfonate crystals are prepared into a stannous methanesulfonate solution, and an antioxidant is added to the stannous methanesulfonate solution to obtain an antioxidant stannous methanesulfonate liquid product.

[0014] As a further technical solution, the antioxidant mentioned above is hydroquinone, and 0.2 to 0.6 g is added per 100 mL of stannous methanesulfonate solution.

[0015] Compared with the prior art, the present invention has the following beneficial effects: Compared with the problems of high-temperature decomposition and unstable yield caused by the temperature difference between the inside and outside of the reactor in traditional oil bath heating, the present invention adopts a combination of infrared and microwave. The infrared temperature control can accurately control the reaction temperature to avoid the decomposition of stannous methanesulfonate caused by excessive temperature. The microwave directly intensifies the molecular motion of the reactant molecules, which significantly accelerates the reaction. Combined with the limitation of the preparation parameters of the present invention, the rapid preparation of stannous methanesulfonate within 1 to 2 hours is achieved, and the yield is stabilized at 84.1% to 92.4%.

[0016] The microwave reactor of the present invention is made of SiC material and utilizes the strong wave absorbing performance of SiC to achieve rapid heating, shorten the reaction time, and also save energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the stannous methanesulfonate product of Example 4 of the present invention; Figure 2 is a graph showing the relationship between the yield of the stannous methanesulfonate product of the present invention and the microwave power (see the red line); Figure 3 is a graph showing the relationship between the yield of stannous methanesulfonate product of the present invention and the reaction temperature (see the red line); Figure 4 The relationship between the yield of stannous methanesulfonate product of the present invention and the molar ratio of tin to methanesulfonic acid raw materials (see the red line); Figure 5 The figure is a relationship diagram between the yield of stannous methanesulfonate product of the present invention and the mass concentration of methanesulfonic acid (see the red line). DETAILED DESCRIPTION

[0018] The present invention is further described in detail below in conjunction with examples, but the implementation mode of the present invention is not limited to the scope represented by the examples.

[0019] The methanesulfonic acid solution used in this embodiment is an industrial standard solution with a mass concentration of 70% and 98%. The density of the methanesulfonic acid solution with a mass concentration of 70% is 1.33 g / cm 3 The density of a 98% methanesulfonic acid solution is 1.481 g / cm 3 .

[0020] Embodiment 1:

[0021] Weigh 14.5 grams of tin flower, and at the same time measure 50.5 ml of 70% methanesulfonic acid solution into a SiC reaction vessel, and then place it in a microwave reactor. Heat to 140°C at a power of 1000W. After reacting for 2 hours, pour the reacted solution from the reaction vessel into a beaker, measure the temperature of the solution in the beaker with an electronic thermometer, cool it naturally and wait for crystals to precipitate. When the temperature drops to 50°C, filter and separate the crystals and unreacted methanesulfonic acid, and wash the stannous methanesulfonate crystals with anhydrous ethanol. The filtrate is recycled and dried and weighed to obtain 34.30 grams of stannous methanesulfonate product, with a yield of 90.9%. Add pure water, methanesulfonic acid and 0.4 g of hydroquinone to the stannous methanesulfonate product to prepare a stannous methanesulfonate solution of the required concentration.

[0022] Embodiment 2:

[0023] Weigh 14.5 grams of tin flower, and at the same time measure 50.5 ml of 70% methanesulfonic acid solution into a SiC reaction vessel, and then place it in a microwave reactor. Heat to 140°C at a power of 500W. After reacting for 2 hours, pour the reacted solution from the reaction vessel into a beaker, measure the temperature of the solution in the beaker with an electronic thermometer, cool it naturally and wait for crystals to precipitate. When the temperature drops to 50°C, filter and separate the crystals and unreacted methanesulfonic acid, and wash the stannous methanesulfonate crystals with anhydrous ethanol. The filtrate is recycled and 31.92 grams of stannous methanesulfonate are obtained after drying and weighing, with a yield of 84.6%. Pure water, methanesulfonic acid and 0.4 g of hydroquinone are added to the stannous methanesulfonate crystals to prepare a stannous methanesulfonate solution of the required concentration.

[0024] Embodiment 3:

[0025] Weigh 14.5 grams of tin flower, and at the same time measure 70% mass concentration, 50.5 ml of methanesulfonic acid solution and put it into a SiC reaction container, and then place it in a microwave reactor. Heat to 130 ° C with a power of 1000 W. After reacting for 2 hours, pour the reacted solution from the reaction container into a beaker, measure the temperature of the solution in the beaker with an electronic thermometer, cool it naturally and wait for crystals to precipitate. When the temperature drops to 50 ° C, filter and separate the crystals and unreacted methanesulfonic acid, and wash the stannous methanesulfonate crystals with anhydrous ethanol. The filtrate is recycled and 31.72 grams of stannous methanesulfonate are obtained after drying and weighing, with a yield of 84.06%. Pure water, methanesulfonic acid and 0.2g of hydroquinone are added to the stannous methanesulfonate crystals to prepare a stannous methanesulfonate solution of the required concentration.

[0026] Embodiment 4:

[0027] Weigh 14.5 grams of tin flower, and at the same time, measure 50.5 ml of 70% methanesulfonic acid solution and put it into a SiC reaction container, and then place it in a microwave reactor. Heat to 140°C at a power of 1500W. After reacting for 2 hours, pour the reacted solution from the reaction container into a beaker, measure the temperature of the solution in the beaker with an electronic thermometer, and cool it naturally until the crystals precipitate. When the temperature drops to 50°C, filter and separate the crystals and unreacted methanesulfonic acid, and wash the stannous methanesulfonate crystals with anhydrous ethanol. The filtrate is recycled, and 34.87 grams of stannous methanesulfonate are obtained after drying and weighing, with a yield of 92.4%. The product appearance is as follows: Figure 1 Pure water, methanesulfonic acid and 0.2 g of hydroquinone are added to stannous methanesulfonate crystals to prepare a stannous methanesulfonate solution of the desired concentration.

[0028] Effect of Experimental Conditions on the Yield of Stannous Methanesulfonate (1) Effect of microwave power on the yield of stannous methanesulfonate

[0029] Weigh 14.5 grams of tin flower, and at the same time, measure 50.5 ml of 70% mass concentration methanesulfonic acid solution and put it into a SiC reaction container, and then place it in a microwave reactor. Heat to 140°C with different microwave powers (500W, 1000W, 1500W). After reacting for 2 hours, pour the reacted solution from the reaction container into a beaker, measure the temperature of the solution in the beaker with an electronic thermometer, and cool it naturally until crystals precipitate. When the temperature drops to 50°C, filter and separate the crystals and unreacted methanesulfonic acid, and wash the stannous methanesulfonate crystals with anhydrous ethanol. The filtrate is recycled and dried and weighed to obtain stannous methanesulfonate. The results are as follows Figure 2 shown.

[0030] Depend on Figure 2 It can be seen that microwave power has a great influence on the yield of stannous methanesulfonate. With the increase of microwave power, the yield of stannous methanesulfonate increases. When the microwave power reaches 1500W, the yield of stannous methanesulfonate reaches 92.4%.

[0031] (2) Effect of temperature on the yield of stannous methanesulfonate Weigh 14.5 grams of tin flower, and at the same time, measure 50.5 ml of 70% mass concentration of methanesulfonic acid solution and put it into a SiC reaction container, and then place it in a microwave reactor. Heat to different reaction temperatures (120℃, 130℃, 140℃, 150℃) at a power of 1500W. After reacting for 2 hours, pour the reacted solution from the reaction container into a beaker, measure the temperature of the solution in the beaker with an electronic thermometer, and cool it naturally until crystals precipitate. When the temperature drops to 50℃, filter and separate the crystals and unreacted methanesulfonic acid, and wash the stannous methanesulfonate crystals with anhydrous ethanol. The filtrate is recycled and dried and weighed to obtain stannous methanesulfonate. The results are as follows Figure 3 shown.

[0032] Depend on Figure 3 It can be seen that with the increase of reaction temperature, the yield of stannous methanesulfonate increases continuously. When the reaction temperature is 140°C, the yield of stannous methanesulfonate reaches a maximum of 91.8%. When the reaction temperature exceeds 140°C, methanesulfonic acid decomposes due to side reactions, causing the yield of stannous methanesulfonate to decrease.

[0033] (3) Effect of material ratio on the yield of stannous methanesulfonate Weigh different weights of tin flowers (29g, 14.5g, 9.7g), measure 70% and 50.5ml methanesulfonic acid solutions in a SiC reaction container, and then place it in a microwave reactor. Heat to a reaction temperature of 140°C at a power of 1500W. After reacting for 2 hours, pour the reacted solution from the reaction container into a beaker, measure the temperature of the solution in the beaker with an electronic thermometer, and cool it naturally until crystals precipitate. When the temperature drops to 50°C, filter and separate the crystals and unreacted methanesulfonic acid, wash the stannous methanesulfonate crystals with anhydrous ethanol, recycle the filtrate, and dry and weigh to obtain stannous methanesulfonate. The results are as follows Figure 4 shown.

[0034] Depend on Figure 4 It can be seen that when the molar ratio of tin flower to methanesulfonic acid is 1:2, the reaction of tin flower is incomplete, and the yield of stannous methanesulfonate is only 81.42%; the molar ratio of tin flower to methanesulfonic acid is 1:4, and the yield of stannous methanesulfonate is the highest, reaching 92%; the yield of stannous methanesulfonate decreases when the molar ratio of tin flower to methanesulfonic acid is 1:6. The reason may be that when the amount of methanesulfonic acid is too large, part of the stannous methanesulfonate will dissolve in the methanesulfonic acid, resulting in a decrease in yield.

[0035] (4) Effect of methanesulfonic acid concentration on the yield of stannous methanesulfonate Weigh 14.5 grams of tin flower, measure different mass concentrations (70%, 85%, 98%), and 50.5 ml of methanesulfonic acid solution into a SiC reaction container, and then place it in a microwave reactor. Heat to a reaction temperature of 140°C at a power of 1500W. After reacting for 2 hours, pour the reacted solution from the reaction container into a beaker, measure the temperature of the solution in the beaker with an electronic thermometer, and cool it naturally until crystals precipitate. When the temperature drops to 50°C, filter and separate the crystals and unreacted methanesulfonic acid, and wash the stannous methanesulfonate crystals with anhydrous ethanol. The filtrate is recycled and dried and weighed to obtain stannous methanesulfonate. The results are as follows Figure 5 shown.

[0036] Depend on Figure 5 It can be seen that when the concentration of methanesulfonic acid is 70%, the yield of stannous methanesulfonate is the highest, which is 92.1%; when the concentration increases to 85% and 98%, the yield decreases to 85.1% and 82.4%. The reason may be that when the concentration is too high, the reaction rate is fast, resulting in the accumulation of products and the occurrence of side reactions, which may affect the yield.

[0037] The above embodiments are only specific examples for further describing the purpose, technical solutions and beneficial effects of the present invention, and the present invention is not limited thereto. Any modification, equivalent replacement, improvement, etc. made within the scope disclosed by the present invention are included in the protection scope of the present invention.

Claims

1. A method for rapidly preparing stannous methanesulfonate, characterized in that: The method comprises the steps of reacting tin with a methanesulfonic acid solution in microwave heating for a period of time, and then cooling, crystallizing, filtering, washing and drying to obtain a stannous methanesulfonate product; the molar ratio of tin to methanesulfonic acid is 1: (2-6), the microwave power is 500W-1500W, the reaction temperature is 120°C-150°C, and the reaction time is 1-2 hours.

2. A method for rapidly preparing stannous methanesulfonate according to claim 1, characterized in that: The tin is tin flower or tin powder.

3. A method for rapidly preparing stannous methanesulfonate according to claim 1, characterized in that: The mass concentration of the methanesulfonic acid solution is 70% to 98%.

4. A method for rapidly preparing stannous methanesulfonate according to claim 3, characterized in that: The molar ratio of tin to methanesulfonic acid is 1:4, the microwave power is 1500 W, the reaction temperature is 140° C., the reaction time is 2 hours, and the mass concentration of the methanesulfonic acid solution is 70%.

5. A method for rapidly preparing stannous methanesulfonate according to claim 1, characterized in that: The cooling crystallization is to naturally cool the reaction product to 40°C to 50°C.

6. A method for rapidly preparing stannous methanesulfonate according to claim 1, characterized in that: The washing is performed using anhydrous ethanol.

7. A method for rapidly preparing stannous methanesulfonate according to claim 1, characterized in that: The microwave reactor of the tin and methanesulfonic acid solution is made of SiC material and is provided with an infrared temperature measuring system.

8. A method for rapidly preparing stannous methanesulfonate according to claim 1, characterized in that: The stannous methanesulfonate product is prepared into a stannous methanesulfonate solution, and an antioxidant is added to the stannous methanesulfonate solution to obtain an antioxidant stannous methanesulfonate liquid product.

9. A method for rapidly preparing stannous methanesulfonate according to claim 8, characterized in that: The antioxidant is hydroquinone, and 0.2 to 0.6 g is added per 100 mL of stannous methanesulfonate solution.

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