Method for synthesizing tributyltin laurate by two-step method

Abstract

The invention relates to a method for synthesizing tributyltin laurate by a two-step method, which comprises the following steps: adding coconut oil into a reactor, stirring, adding a proper amount of alkali liquor, and carrying out constant-temperature saponification reaction to obtain clear and transparent saponification liquid; then adding tributyltin chloride, continuously carrying out constant-temperature reaction, and gradually synthesizing tributyltin laurate; and after the reaction is finished, standing for phase splitting, collecting an organic phase, washing the organic phase with water, and drying to obtain a tributyltin laurate product with the tin mass content of 24.5 + / -0.5%, the chlorine mass content of less than or equal to 0.5% and the water mass content of less than or equal to 0.5%. The production process is safe, reliable and environment-friendly. And the prepared tributyltin chloride product is high in purity and stable in quality.

Description

Technical Field

[0001] The invention belongs to the technical field of deep processing of organic tin products, and specifically relates to an innovative two-step method for synthesizing tributyltin laurate. Background Art

[0002] Organotin compounds are widely used in many fields. Tributyltin laurate (also known as tributyltin laurate) is an important organotin compound. As one of the organotin series chemical products with the general formula R3SnX, tributyltin laurate occupies a pivotal position in many fields today. In the agricultural field, it can be used as a highly efficient fungicide to effectively protect crops from pests and diseases. In the wood industry, it is used in the protective treatment of wood to significantly improve the durability and corrosion resistance of wood. The shipbuilding industry also has a wide demand for tributyltin laurate. Due to its high biological activity, it is widely used in the synthesis of important compounds such as α,β-unsaturated methyl ketones and isoxazoles. At the same time, it can also be used to prepare antifouling agents for ship paints, effectively preventing marine organisms from attaching to the surface of the hull and reducing the resistance of the ship's navigation; in addition, it can also be used as a fumigant, disinfectant, fungicide, algaecide, mildewicide, etc., to provide all-round protection for the safe navigation and long-term storage of ships. In the industrial field, tributyltin laurate also plays an important role in the papermaking, textile, painting and other industries. It can be used as a protective agent to improve the quality and performance of products. In the pharmaceutical industry, tributyltin laurate is used as an intermediate for synthetic medicines. Tributyltin laurate not only plays an important role in the above industries, but also plays a key role as a catalyst in polymerization reactions, promoting the efficient conduct of related chemical reactions.

[0003] In the field of organotin deep processing technology, the continuous exploration of efficient, safe and environmentally friendly organotin synthesis methods has always been the focus of research. The traditional synthesis method of tributyltin laurate has various problems, such as complex process, safety hazards caused by the use of flammable and explosive solvents, environmental unfriendliness and unstable product quality. Therefore, the development of an efficient, safe, environmentally friendly and cost-effective synthesis method of tributyltin laurate has become an urgent need. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and provide a safe and reliable two-step method for synthesizing tributyltin laurate which can prepare a high-purity product.

[0005] The technical solution adopted by the present invention is as follows: A two-step method for synthesizing tributyltin laurate comprises the following steps: (1) Add coconut oil into a reactor, stir, add an appropriate amount of alkali solution, and then react at a constant temperature. The alkali solution and lauric acid in the coconut oil undergo saponification reaction to obtain a clear and transparent saponified liquid; (2) adding tributyltin chloride to the clear and transparent saponified liquid under stirring, and continuing the reaction at a constant temperature. At this time, tributyltin chloride further reacts with the saponified liquid to gradually synthesize tributyltin laurate; (3) After the reaction is completed, stirring is stopped and the reaction system is allowed to stand for phase separation; at this stage, the salt water phase rich in chloride ions is gradually separated from the organic phase. By removing the salt water phase and collecting the organic phase, a light yellow oily transparent liquid is obtained, which contains the initially synthesized tributyltin laurate; (4) The organic phase is washed with water to remove residual impurities, and then dried to obtain a tributyltin laurate product having a tin content of 24.5±0.5%, a chlorine content of ≤0.5%, and a water content of ≤0.5%.

[0006] Furthermore, the alkali solution in step (1) is one or more of sodium hydroxide solution, potassium hydroxide solution, and ammonia water, the mass concentration of the alkali solution is 10%-12%, and the actual amount of the alkali solution is 1.1 times the theoretical amount. Such alkali solution concentration and amount can ensure that the alkali solution fully reacts with the lauric acid in the coconut oil, thereby improving the reaction efficiency and the purity of the product.

[0007] The mass content of lauric acid in the coconut oil described in step (1) is 50%. This specific content of lauric acid is crucial for the synthesis of tributyltin laurate, and can ensure the smooth progress of the reaction and the stable quality of the product. When selecting coconut oil, the content of lauric acid should be strictly tested to ensure that it meets the requirements. If the lauric acid content is too high or too low, it will affect the progress of the reaction and the quality of the product.

[0008] Furthermore, the reaction temperature of the isothermal reaction in step (1) is 60-65°C, and the isothermal reaction time is 1.5 hours. Within this temperature range, the reaction of the alkali solution and lauric acid can proceed at an appropriate speed, which not only ensures the efficiency of the reaction, but also avoids the side reactions that may be caused by excessively high temperatures. The isothermal reaction time of 1.5 hours can allow the reaction to proceed fully and ensure the formation of the intermediate product.

[0009] Furthermore, the reaction temperature of the isothermal reaction in step (2) is 70-75°C, and the isothermal reaction time is 1.5 hours. At this stage, a higher reaction temperature is conducive to the reaction of tributyltin chloride with the intermediate product, accelerating the reaction speed and improving production efficiency. Similarly, a isothermal reaction time of 1.5 hours can ensure that the reaction is fully carried out, making the synthesis of tributyltin laurate more complete and obtaining a high-quality product.

[0010] Furthermore, the standing phase separation time in step (3) is 10-15 minutes. Within this time range, the brine phase and the organic phase in the reaction system can be fully separated, ensuring the purity of the organic phase, providing a good foundation for subsequent processing steps.

[0011] Furthermore, the washing in step (4) is carried out 2-3 times; and the drying temperature is 100°C. By washing with water 2-3 times, the residual impurities in the organic phase can be effectively removed, and the purity of the tributyltin laurate product can be improved. The drying temperature of 100°C can remove the moisture in the product in a shorter time, ensuring the stable quality and storage performance of the product.

[0012] The present invention has at least the following advantages: (1) The present invention, by precisely controlling the reaction steps and conditions, does not use flammable and explosive solvents such as toluene and cyclohexane, thereby greatly improving the safety of the production process, reducing potential safety risks, and preparing a high-purity tributyltin laurate product. In traditional synthesis methods, the use of these flammable and explosive solvents not only increases safety hazards, but also may cause serious pollution to the environment. The method of the present invention completely abandons these solvents, providing a strong guarantee for safe production and environmental protection.

[0013] (2) The present invention adopts a two-step method to prepare tributyltin laurate. In the first step, alkali solution and lauric acid in coconut oil are subjected to saponification reaction to obtain a clear and transparent saponified liquid. In the second step, tributyltin chloride is added to the clear and transparent saponified liquid to continue the constant temperature reaction to synthesize tributyltin laurate. Since the saponification reaction is completed to obtain a clear and transparent liquid, the addition of tributyltin chloride and the liquid are mutually soluble, which can make the reaction materials contact and react better, thereby improving the reaction yield. The synthesized tributyltin laurate is insoluble in water and can produce a clear phase separation interface, thereby making the separation of the aqueous phase containing salt and chloride ions more thorough, which can effectively reduce the number of water washing and desalting times.

[0014] (3) After the reaction is completed, the organic phase and the salt water phase are both in liquid form and are immiscible. By standing the phases for phase separation, the salt water phase rich in chloride ions can be separated more thoroughly, which can effectively reduce the content of chloride ions in the organic phase, thereby improving the purity of the obtained tributyltin laurate product. In addition, after in-depth research, it was found that the tributyltin laurate product obtained by replacing lauric acid with coconut oil having a lauric acid content of 50% has excellent quality. Compared with the method of directly using lauric acid for synthesis, the cost is greatly reduced and the market competitiveness of the product is improved.

[0015] (4) The method of the present invention has the characteristics of safe process, simple production equipment, easy-to-control production conditions, high production efficiency, high yield, low production cost, and stable product quality. The tributyltin laurate product produced by the method of the present invention has stable and reliable quality, and the key indicators of the product are: tin content 24.5±0.5%, chlorine content ≤0.5%, water content ≤0.5%, tin direct recovery rate greater than 97.0%, and up to 98.5%. These key indicators fully reflect the high quality and high performance of the tributyltin laurate product produced by the method of the present invention, which can meet the demand for high-quality tributyltin laurate in agriculture, wood, shipbuilding and other industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below through specific implementation cases. The process flow of the method of the present invention is shown in Figure 1, which clearly shows the specific operations of each step and the flow of materials. Those skilled in the art should understand that these implementation cases are only a specific description of the present invention, rather than a limitation of the scope of protection of the present invention. Example 1

[0018] A two-step method for synthesizing tributyltin laurate. Add 615g of coconut oil with a lauric acid content of 50% by mass to a four-necked reaction bottle, maintain the temperature at 55°C, start stirring, and slowly add 1350g of a sodium hydroxide solution with a mass concentration of 10% in a beaker to the four-necked reaction bottle and mix with the coconut oil using a glass rod. Perform saponification reaction at a constant temperature of 65°C for 1.5 hours. After the constant temperature is completed, let it stand for 15 minutes, wait for the foam on the surface of the saponified liquid to disappear, and observe whether the liquid is clear. After confirming that it is clear, start stirring, maintain the temperature at 65°C, and slowly add 1000g of tributyltin chloride to the clear saponified liquid. After the addition is completed, keep the temperature at 75°C for 1.5 hours. Stop stirring after the reaction is completed, let it stand for 15 minutes, and let the reaction system stand for phase separation. The lower layer after phase separation is a salt water phase rich in chloride ions, and the upper layer is an organic phase containing the preliminarily synthesized tributyltin laurate. The organic phase is a light yellow oily transparent liquid. The salt water phase is separated and discharged into the sewage treatment system, and the organic phase is collected. The organic phase was washed three times, and each time 1500g of distilled water was added for washing, and the temperature was kept at 65℃ for 30 minutes until the pH of the aqueous phase was 7.5. Except that the water of the first washing directly entered the sewage system, the water of the second washing and the third washing could be used for the next alkali preparation and the first washing, so as to realize recycling. Finally, the washed organic phase was dried at 100℃ and vacuum-80Kpa to obtain a slightly turbid light yellow liquid, and then filtered to obtain 1038.4g of clear light yellow liquid, which was the desired tributyltin laurate product, with a tin content of 24.36%, a chlorine content of 0.13%, a moisture content of 0.17%, and a Pt-Co (platinum-cobalt index) of 73.

[0019] The saponification reaction formula of coconut oil containing lauric acid and sodium hydroxide is as follows: C 12 H 24 O2 (from coconut oil) + NaOH → C 12 H 23 O2Na + H2O The chemical reaction formula of saponification liquid and tributyltin chloride is as follows: C 12 H 23 O2Na + (C4H9)3SnCl → (C4H9)3SnC 12 H 23 O2 + NaCl The tributyltin laurate product generated by the reaction of lauric acid, sodium hydroxide and tributyltin chloride is a light yellow oily transparent liquid that is insoluble in water. Its density is quite different from that of the salt water phase rich in chloride ions, and the stratification interface is obvious. This characteristic ensures that the tributyltin laurate is completely separated from the salt water phase, and avoids the chloride ions entering the product, resulting in an excessively high chloride content in the final product tributyltin laurate.

[0020] The mass content of lauric acid in coconut oil is limited to 50%. This specific content of lauric acid is essential for the synthesis of tributyltin laurate, which can ensure the smooth progress of the reaction and the stability of the product quality. When selecting coconut oil, the content of lauric acid should be strictly tested to ensure that it meets the requirements. If the lauric acid content is too high or too low, it may affect the progress of the reaction and the quality of the product. In addition, the reaction temperature and reaction time of the constant temperature reaction must also be precisely controlled so that the reaction of alkali solution and lauric acid can proceed at an appropriate speed, which not only ensures the reaction efficiency, but also avoids side reactions that may be caused by excessively high temperatures. The constant temperature reaction time of 1.5 hours can fully carry out the reaction, ensure the generation of saponified liquid, and obtain high-quality tributyltin laurate products. Example 2

[0021] A two-step method for synthesizing tributyltin laurate. Add 615g of coconut oil with a lauric acid content of 50% by mass to a four-necked reaction bottle, maintain the temperature at 55°C, start stirring, and slowly add 1900g of a potassium hydroxide solution with a mass concentration of 12% in a beaker to the four-necked reaction bottle and mix with the coconut oil using a glass rod. Perform saponification reaction at a constant temperature of 63°C for 1.5 hours. After the constant temperature is completed, let it stand for 12 minutes, wait for the foam on the surface of the saponified liquid to disappear, and observe whether the liquid is clear. After confirming that it is clear, start stirring, maintain the temperature at 63°C, and slowly drop 1000g of tributyltin chloride into the clear saponified liquid. After the addition is completed, keep the temperature at 73°C for 1.5 hours. Stop stirring after the reaction is completed, let it stand for 10 minutes, and let the reaction system stand for phase separation. The lower layer after phase separation is the brine phase, and the upper layer is the organic phase containing the preliminarily synthesized tributyltin laurate. The organic phase is a light yellow oily transparent liquid. Collect the organic phase. The organic phase was washed twice, each time with 1500g of distilled water, and stirred at 65°C for 30 minutes until the pH of the aqueous phase was 7.5. Finally, the washed organic phase was dried at 100°C and vacuum -80Kpa to obtain a slightly turbid light yellow liquid, which was then filtered to obtain 1041.3g of clear light yellow liquid, which was the desired tributyltin laurate product, with a tin content of 24.51%, a chlorine content of 0.24%, a moisture content of 0.35%, and a Pt-Co (platinum-cobalt index) of 86. Example 3

[0022] A two-step method for synthesizing tributyltin laurate. Add 615g of coconut oil with a lauric acid mass content of 50% to a four-necked reaction bottle, maintain the temperature at 55°C, start stirring, and slowly add 514g of ammonia water with a mass concentration of 11% in the beaker to the four-necked reaction bottle and mix with the coconut oil using a glass rod. Perform saponification reaction at a constant temperature of 60°C for 1.5 hours. After the constant temperature is completed, let it stand for 10 minutes, wait for the foam on the surface of the saponified liquid to disappear, and observe whether the liquid is clear. After confirming that it is clear, start stirring, maintain the temperature at 60°C, and slowly add 1000g of tributyltin chloride to the clear saponified liquid. After the addition is completed, keep the temperature at 70°C for 1.5 hours. Stop stirring after the reaction is completed, let it stand for 12 minutes, and let the reaction system stand for phase separation. The lower layer after phase separation is the brine phase, and the upper layer is the organic phase containing the preliminarily synthesized tributyltin laurate. The organic phase is a light yellow oily transparent liquid. Collect the organic phase. The organic phase was washed three times, each time with 1500g of distilled water, and stirred at 65°C for 30 minutes until the pH of the aqueous phase was 7.5. Finally, the washed organic phase was dried at 100°C and vacuum -80Kpa to obtain a slightly turbid light yellow liquid, which was then filtered to obtain 1042.6g of clear light yellow liquid, which was the desired tributyltin laurate product, with a tin content of 24.16%, a chlorine content of 0.076%, a moisture content of 0.08%, and a Pt-Co (platinum-cobalt index) of 55.

[0023] Unless otherwise specified, the percentages described in the present invention are all by mass.

Claims

1. A two-step method for synthesizing tributyltin laurate, characterized in that: The following steps are involved: (1) Add coconut oil into a reactor, stir, add an appropriate amount of alkali solution, and then react at a constant temperature. The alkali solution and lauric acid in the coconut oil undergo saponification reaction to obtain a clear and transparent saponified liquid; (2) adding tributyltin chloride to the clear and transparent saponified liquid under stirring, and continuing the reaction at a constant temperature. At this time, tributyltin chloride further reacts with the saponified liquid to gradually synthesize tributyltin laurate; (3) After the reaction is completed, stirring is stopped and the reaction system is allowed to stand for phase separation; at this stage, the salt water phase rich in chloride ions is gradually separated from the organic phase. By removing the salt water phase and collecting the organic phase, a light yellow oily transparent liquid is obtained, which contains the initially synthesized tributyltin laurate; (4) The organic phase is washed with water to remove residual impurities, and then dried to obtain a tributyltin laurate product having a tin content of 24.5±0.5%, a chlorine content of ≤0.5%, and a water content of ≤0.5%.

2. The two-step method for synthesizing tributyltin laurate according to claim 1, characterized in that: The alkali solution in step (1) is one or more of sodium hydroxide solution, potassium hydroxide solution, and ammonia water, the mass concentration of the alkali solution is 10%-12%, and the actual amount of the alkali solution is 1.1 times the theoretical calculated amount; the mass content of lauric acid in the coconut oil is 50%.

3. A two-step method for synthesizing tributyltin laurate according to claim 1 or 2, characterized in that: The reaction temperature of the isothermal reaction in step (1) is 60-65°C, and the isothermal reaction time is 1.5 hours.

4. The two-step method for synthesizing tributyltin laurate according to claim 1, characterized in that: The reaction temperature of the isothermal reaction in step (2) is 70-75°C, and the isothermal reaction time is 1.5 hours.

5. The two-step method for synthesizing tributyltin laurate according to claim 1, characterized in that: The standing phase separation time in step (3) is 10-15 minutes.

6. The two-step method for synthesizing tributyltin laurate according to claim 1, characterized in that: The water washing in step (4) is organic, and the number of water washings is 2-3 times; the drying temperature is 100°C.

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