Preparation process of chlorobromoisocyanuric acid

Abstract

The invention provides a preparation process of chlorobromoisocyanuric acid, which comprises the following steps: cyanuric acid, bromide and sodium hypochlorite are subjected to halogenation reaction under the action of a catalyst to obtain chlorobromoisocyanuric acid; wherein the catalyst is a copper-manganese bimetallic composite oxide. According to the preparation process of the chlorobromoisocyanuric acid, disclosed by the invention, the synergistic catalysis effect of the CuO-MnO2 composite oxide is exerted, so that the high-purity chlorobromoisocyanuric acid can be obtained at high yield; the operation process of the whole preparation process is simple and convenient, product purification and catalyst recovery operation is simple, solid waste generation is greatly reduced, the production cost is reduced, and the method is a green and environment-friendly chlorobromoisocyanuric acid preparation process and has excellent economic benefits and industrial application potential.

Description

Technical Field

[0001] This invention relates to the field of pesticide chemical technology, specifically to a preparation process for chlorobromoisocyanuric acid. Background Technology

[0002] Chlorobromoisocyanuric acid, also known as disinfectant or sterilizing agent, is a highly efficient and broad-spectrum oxidizing disinfectant widely used in agriculture, water treatment, and public health. Its core synthetic step involves the halogenation of cyanuric acid molecules. For many years, improvements to its production process have mainly focused on replacing halogenation sources and improving reaction efficiency, but have not fundamentally solved key issues such as safety, catalyst recovery, and process integration.

[0003] Existing technologies generally employ the direct use of highly hazardous halogen sources. Early processes, such as those in patents CN102746246A and CN109418275A, directly used liquid chlorine and liquid bromine as halogenating agents. While these methods involve direct reactions, they have fatal flaws: both chlorine and liquid bromine are highly toxic and corrosive chemicals, posing a significant threat to production equipment (requiring special corrosion protection), the operating environment, and personnel safety. Furthermore, their storage and transportation costs are extremely high.

[0004] In addition, existing processes suffer from lengthy procedures and catalyst recovery issues. For example, patent CN116283809A uses pyridine-based ionic liquids to synthesize cyanuric acid, followed by halogenation via surfactant suspension, resulting in a lengthy overall process; patent CN102746246A relies on cuprous ion catalysts, whose metal residues may pose environmental risks and are difficult to recover; and patent CN116283809A suffers from the problem of non-recoverable catalysts. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention discloses a preparation process for chlorobromoisocyanuric acid, which solves the technical problems of safety risks, cumbersome operation, and difficulty in catalyst recovery in existing technologies.

[0006] To achieve the above technical objectives, this invention proposes a preparation process for chlorobromoisocyanuric acid, the preparation process comprising: halogenation reaction of cyanuric acid, bromide and sodium hypochlorite under the action of a catalyst to obtain chlorobromoisocyanuric acid; wherein the catalyst is a copper-manganese bimetallic composite oxide.

[0007] Through extensive experiments, the research team unexpectedly discovered that using copper-manganese bimetallic composite oxides to catalyze the nucleophilic halogenation reaction system of cyanuric acid, bromide, and sodium hypochlorite can safely and efficiently catalyze the reaction. Further experiments confirmed that the synergistic catalytic effect between the active metal elements Cu and Mn in the preparation process of this invention is far superior to that of single Cu and Mn oxides or composite oxides of Cu and Mn with other known metals (such as single metal oxides of Fe, Co, Ni, etc. and their combinations), exhibiting excellent catalytic effects. The research team hypothesizes that in the chlorobromoisocyanuric acid preparation reaction system of this invention, sodium hypochlorite itself is a weak oxidant, but the CuO-MnO2 bimetallic composite can catalyze its transformation into a more potent oxidizing active component. These active components can efficiently oxidize bromide ions to hypobromic acid or bromide cation equivalents, and synergistically promote the efficient and uniform halogenation reaction of cyanuric acid on the catalyst surface.

[0008] Furthermore, once the reaction is complete, the preparation process of this invention can achieve the purification of the target product and the recovery of the solid catalyst through simple solid-liquid separation; not only is the process simple, but the recovered catalyst can be recycled more than 15 times, which greatly reduces solid waste and lowers production costs, making it a green and environmentally friendly preparation process.

[0009] Furthermore, based on metal elements, the molar ratio of copper to manganese in the catalyst is (0.1~10):1. By optimizing the ratio of active components copper and manganese in the catalyst, the synergistic effect between the two can be enhanced, thereby improving the process yield and product purity. Embodiments of this invention illustrate the process of catalyzing chlorobromoisocyanuric acid with catalysts of different copper to manganese molar ratios. In an optional example of this invention, the molar ratio of copper to manganese in the catalyst is (0.25~4):1, preferably (0.5~2):1.

[0010] Furthermore, the amount of catalyst used is 1% to 10% of the mass of cyanuric acid. Appropriate amounts of catalyst can improve reaction efficiency while reducing process costs. In an optional example of the present invention, the amount of catalyst used is 2% to 8% of the mass of cyanuric acid.

[0011] Furthermore, the catalyst is prepared by co-precipitation, impregnation, or mechanical mixing. Embodiments of this invention illustrate the process of preparing chlorobromoisocyanuric acid catalysts using different methods. In an optional example of this invention, the catalyst is prepared by co-precipitation; the research team hypothesizes that co-precipitation can promote more uniform contact and recombination of copper and manganese elements, thereby achieving a better synergistic catalytic effect.

[0012] Furthermore, the molar ratio of cyanuric acid, bromine in the bromide, and chlorine in sodium hypochlorite is 1:(0.8~1.5):(1.5~2.5), which can suppress side reactions and effectively drive the reaction equilibrium to the forward direction, thereby improving the yield and purity of chlorobromoisocyanuric acid. In an optional example of the present invention, the molar ratio of cyanuric acid, bromine in the bromide, and chlorine in sodium hypochlorite is 1:(1.0~1.2):(1.8~2.2).

[0013] Furthermore, the bromide is sodium bromide and / or potassium bromide. In a preferred embodiment of the invention, by using inexpensive and stable sodium (potassium) bromide instead of highly hazardous liquid bromine and unstable sodium hypobromite, safety can be improved from the source, and the cost of raw materials and equipment can be reduced. Embodiments of the invention illustrate examples using sodium bromide and / or potassium bromide as the bromide.

[0014] Furthermore, the reaction temperature of the preparation process is 10~25℃, and the pH value of the reaction system is 4.5~6.0. The overall reaction conditions are mild and highly operable. It should be noted that the specific operation for controlling the pH value of the reaction system is not limited in this invention. The pH value of the reaction system can be monitored online during the process, and an appropriate amount of acid can be added to adjust the pH value. The type of acid is not limited in this invention; it can be selected as needed in actual operation, such as one or more of hydrochloric acid, nitric acid, and sulfuric acid, without limiting the scope of protection of this invention.

[0015] Furthermore, the preparation process is carried out under an inert atmosphere. It should be noted that the inert atmosphere described in this invention refers to a gaseous environment composed of gases that do not chemically interact with the reactants, such as a nitrogen atmosphere, or an atmosphere formed by gases of Group 0 elements in the periodic table (such as argon).

[0016] Furthermore, the preparation process includes the following steps: Step (1): Add the cyanuric acid, the bromide and the catalyst to water and mix to obtain a suspension; Step (2): Add the sodium hypochlorite solution dropwise to the suspension, and after the addition is complete, age the solution to obtain the chlorobromoisocyanuric acid.

[0017] The overall preparation process of this invention is concise, easy to operate and control, and has mild reaction conditions, making it a highly industrialized and economically viable process for preparing chlorobromoisocyanuric acid.

[0018] It should be noted that there are no special requirements for the type of water used in this invention, and those skilled in the art can choose according to their needs. For example, the water used is deionized water.

[0019] Furthermore, the mass ratio of cyanuric acid to water is 1:(3~10), which provides a suitable concentration of reactants and improves reaction efficiency.

[0020] Furthermore, the concentration of the sodium hypochlorite solution is 10% to 30%, and the optimization of the sodium hypochlorite solution concentration is due to the regulation of the reaction process. In an optional example of the present invention, the concentration of the sodium hypochlorite solution is 20% to 25%.

[0021] Furthermore, the dropping rate of the sodium hypochlorite solution is 10-30 mL / min. In an optional example of the invention, the dropping rate of the sodium hypochlorite solution is 15-25 mL / min.

[0022] Furthermore, the aging process is carried out at a temperature of 10~30°C for a time of 0.5~5 hours. In an optional example of the present invention, the aging process is carried out for a time of 1~3 hours.

[0023] Furthermore, step (1) further includes adding a dispersant to the water, thereby promoting the formation of a uniform suspension system. Optionally, the dispersant includes at least one of sodium dodecylbenzenesulfonate, sodium laurate, and sodium oleate. Optionally, the amount of dispersant added is 0.5% to 5% of the mass of the cyanuric acid, preferably 1% to 3%.

[0024] Furthermore, the preparation process also includes step (3): solid-liquid separation of the reacted materials to recover the catalyst, and the recovered catalyst can be recycled after washing. In an optional example of the present invention, the liquid phase material obtained from the solid-liquid separation can be cooled and crystallized to obtain a high-purity chlorobromoisocyanuric acid product. In an optional example of the present invention, the solid-liquid separation is carried out at 40~60℃ to improve the solubility of the target substance and improve the solid-liquid separation efficiency. It should be noted that the specific operation of solid-liquid separation is not limited in the present invention, as long as the operation can separate the solid catalyst from the reaction system, such as by means of filtration, centrifugation or vacuum filtration.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: The preparation process of chlorobromoisocyanuric acid of the present invention uses copper-manganese bimetallic composite oxide as a catalyst to catalyze the nucleophilic halogenation reaction of cyanuric acid, bromide and sodium hypochlorite, giving full play to the synergistic catalytic effect of CuO-MnO2 composite oxide, which can obtain high-purity chlorobromoisocyanuric acid in high yield; the overall preparation process is simple to operate, the product purification and catalyst recovery are simple to operate, which greatly reduces the generation of solid waste and lowers the production cost. It is a green and environmentally friendly preparation process of chlorobromoisocyanuric acid with excellent economic benefits and industrial application potential. Detailed Implementation

[0026] To facilitate understanding of the present invention, a more comprehensive description will be provided below, along with preferred embodiments. However, it should be understood that these embodiments are merely for more detailed explanation and should not be construed as limiting the invention in any way, i.e., not intended to limit the scope of protection of the invention.

[0027] Unless otherwise defined, the technical terms used in the following embodiments have the same meanings as commonly understood by those skilled in the art to which this invention pertains. Unless otherwise specified, the experimental reagents used in the following embodiments are conventional biochemical reagents; and the experimental methods described are conventional methods.

[0028] Furthermore, it should be noted that although the various steps of the preparation method of the present invention are described in a specific order in the description of the present invention, these orders are not restrictive. Without departing from the basic principles of the present invention, those skilled in the art can perform the steps in different orders.

[0029] All numerical designations, such as pH, temperature, flow rate, and range, are approximate values. It should be understood that, while not always explicitly stated, all numerical designations are preceded by the term "approximately." It should also be understood that, while not always explicitly stated, the reagents described herein are merely examples, and their equivalents are known in the art.

[0030] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1–5” is disclosed, the described range should be interpreted as including ranges “1–4”, “1–3”, “1–2”, “1–2 and 4–5”, “1–3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0031] It should also be noted that, unless otherwise specified, the term "concentration" in this invention refers to mass concentration.

[0032] The catalyst used in the embodiments of the present invention may be prepared by coprecipitation, and the coprecipitation method may include the following steps: Step S1: Dissolve the copper source and manganese source in water to obtain a mixed salt solution; Step S2: Contact the mixed salt solution with a precipitant to obtain a catalyst precursor; Step S3: The catalyst precursor is washed, dried and calcined to obtain the catalyst.

[0033] The copper source and the manganese source can be selected from soluble metal salts of copper and manganese, such as one or more of the corresponding metal nitrates, sulfates or chlorides, and can be selected as needed during actual preparation.

[0034] The precipitant is a compound that causes copper and manganese to precipitate, such as at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, ammonium carbonate, and ammonia. The concentration of the precipitant is not limited in this invention; however, to improve the catalyst preparation efficiency, the concentration of the precipitant can be selected from 0.8 to 2 mol / L.

[0035] The precipitation operation in step S2 can be carried out at 50~70℃ and pH 9.0~10.0. Step S2 may include aging after the mixed salt solution comes into contact with the precipitant, and the reacted material may be allowed to stand for 1.5~3 hours. Step S2 may also include solid-liquid separation of the reacted material, obtaining the catalyst precursor filter cake by means of filtration, centrifugation or vacuum filtration.

[0036] The washing operation involves washing the precursor with deionized water until the pH value is neutral.

[0037] The drying operation can be carried out in an oven at 100~150℃ for 8~24 hours.

[0038] The calcination operation can be carried out at 300~450℃ for 3~10h to obtain the catalyst.

[0039] It should be noted that the present invention does not limit the manner in which the mixed salt solution comes into contact with the precipitant. Methods such as direct mixing, dropwise addition, or co-precipitation can be used, and this does not limit the scope of protection of the present invention.

[0040] Exemplarily, the present invention illustrates a preparation process for a copper-manganese bimetallic composite oxide catalyst: Step S1: Based on the target Cu / Mn molar ratio of 1.5:1, accurately weigh 50 g of Cu(NO3)2·3H2O and 36 g of Mn(NO3)2·4H2O, and dissolve them together in 1000 mL of deionized water to prepare a mixed salt solution. Separately prepare a 1.0 mol / L Na2CO3 solution as a precipitant.

[0041] Step S2: Under constant temperature water bath conditions of 60℃ and vigorous stirring at 500 rpm, the mixed salt solution and precipitant solution were added dropwise at similar rates to a beaker containing 500 mL of deionized water (as seed crystals) using a dual-channel peristaltic pump. The pH of the reaction system was stabilized between 9.0 and 10.0 by adjusting the dropping rate of the precipitant. After the addition was complete, the system was aged for another 2 hours while maintaining the 60℃ and stirring conditions.

[0042] Step S3: After the reaction is complete, the precipitate is filtered and washed repeatedly with a large amount of deionized water until the filtrate is neutral (approximately pH=7) as measured by pH paper. The resulting filter cake is placed in an oven and dried at 120°C for 12 hours. Finally, the dried precursor powder is placed in a muffle furnace and heated to 400°C at a programmed heating rate of 2°C / min, and calcined at this temperature for 4 hours. After natural cooling in the furnace, it is ground to obtain a black powder product, which is the CuO-MnO2 composite oxide.

[0043] Example 1

[0044] A process for preparing chlorobromoisocyanuric acid includes the following steps: Step (1): Under nitrogen protection, add the following to the reactor: 323g (2.5mol) of cyanuric acid, 289g (2.8mol) of sodium bromide, 16g of CuO-MnO2 catalyst (Cu / Mn molar ratio of 1.5:1, amount of which is 5% of the mass of cyanuric acid), 5g of sodium dodecylbenzenesulfonate, and 2000g of deionized water (water:cyanuric acid mass ratio = 6:1). Stir at 15℃ to form a uniform suspension.

[0045] Step (2): Start by slowly adding 25% sodium hypochlorite solution (6 mol) at a rate of 15-25 ml / min; and add appropriate dilute hydrochloric acid (10%) to maintain the pH at 5.5±0.2, and keep the reaction at the temperature for 1 hour.

[0046] Step (3): When the residual amount of cyanuric acid is <0.5%, the temperature is raised to 50℃ to perform hot filtration of the reaction mixture, separate and recover the solid catalyst, cool the filtrate to less than 5℃, and stir to crystallize for 1 hour; filter and dry to obtain 585.4g of white powdered product chlorobromoisocyanuric acid with a purity of 98.9% and a yield of 96.6%. The solid catalyst is recovered, the filter cake (catalyst) is washed with a small amount of water, and dried at 120℃ for 2 hours to obtain 15.8g which can be directly used in the next round of reaction.

[0047] Comparative Example 1 The steps include: (1): Under nitrogen protection, add 323 g (2.5 mol) of cyanuric acid, 289 g (2.8 mol) of sodium bromide, 5 g of sodium dodecylbenzene sulfonate without catalyst, and 2000 g of deionized water (water: cyanuric acid mass ratio = 6:1) to the reactor and stir at 15°C to form a uniform suspension.

[0048] Step (2): Slowly add 25% sodium hypochlorite solution (6 mol) dropwise, followed by appropriate dilute hydrochloric acid (10%) to maintain the pH at 5.5 ± 0.2, and keep the reaction at this temperature for 1 hour. The residual amount of cyanuric acid was detected as <25.8%. Subsequently, the reaction time was extended to 5 hours, and the residue was still >10%. The filtrate was cooled to below 5°C and stirred for crystallization for 1 hour. After filtration and drying, 486.6 g of white powdery product chlorobromoisocyanuric acid was obtained, with a purity of 92.3% and a yield of 80.3%.

[0049] Comparative Example 2 The preparation process and parameter control of chlorobromoisocyanuric acid in this comparative example are the same as in Example 1, except that sodium hypobromite is used instead of sodium bromide, and sodium hypochlorite is added. Specifically: Step (1): Under nitrogen protection, add 323 g (2.5 mol) of cyanuric acid, 302.3 g (2.5 mol) of sodium hypobromite, 5 g of sodium dodecylbenzenesulfonate, and 2000 g of deionized water (water:cyanuric acid mass ratio = 6:1) to the reactor and stir at 15°C to form a uniform suspension. Begin by slowly adding 6 mol of 25% sodium hypochlorite solution and then adding appropriate amount of dilute hydrochloric acid (10%) to maintain the pH at 5.5 ± 0.2. Incubate the reaction for 3-4 hours.

[0050] Step (2): The residual amount of cyanuric acid was detected to be <1.0%, and the mixture was stirred and crystallized for 1 hour; after filtration and drying, 526.0 g of white powder product chlorobromoisocyanuric acid was obtained, with a purity of 94.4% and a yield of 86.8%.

[0051] Comparative Example 3 Includes the following steps: Step (1): Under nitrogen protection, add the following to the reactor: 323 g (2.5 mol) cyanuric acid, 289 g (2.8 mol) sodium bromide, 16 g CuO catalyst (5% of the mass of cyanuric acid), 5 g sodium laurate, and 2000 g deionized water (water: cyanuric acid mass ratio = 6:1). Stir at 15°C to form a uniform suspension.

[0052] Step (2): Slowly add 25% sodium hypochlorite solution (6 mol) dropwise, followed by appropriate dilute hydrochloric acid (10%) to maintain the pH at 5.5 ± 0.2, and keep the reaction at this temperature for 1 hour. When the residual cyanuric acid content is <0.5%, heat to 50°C to perform hot filtration of the reaction mixture, separate and recover the solid catalyst, cool the filtrate to below 5°C, and stir to crystallize for 1 hour; filter and dry to obtain a white powder product, chlorobromoisocyanuric acid, 542.4 g, purity 96.1%, yield 89.5%.

[0053] Comparative Example 4 Includes the following steps: (1) Under nitrogen protection, add the following to the reactor: 323 g (2.5 mol) cyanuric acid, 289 g sodium bromide (2.8 mol), 16 g MnO2 catalyst (5% of the mass of cyanuric acid), 6 g sodium oleate, and 2000 g deionized water (water:cyanuric acid mass ratio = 6:1). Stir at 15°C to form a uniform suspension. Slowly add 25% sodium hypochlorite solution (6 mol) and appropriate dilute hydrochloric acid (10%) to maintain the pH at 5.5 ± 0.2. Keep the reaction at this temperature for 1 h.

[0054] (2): If the residual amount of cyanuric acid is <0.5%, heat to 50°C, hot filter the reaction mixture, separate and recover the solid catalyst, cool the filtrate to less than 5°C, stir and crystallize for 1 hour; filter and dry to obtain 510.3g of white powder product chlorobromoisocyanuric acid with a purity of 94.5% and a yield of 84.2%.

[0055] Comparative Example 5 The preparation process and parameter control of chlorobromoisocyanuric acid in this comparative example are the same as in Example 1, except that the catalyst used is an Fe2O3-MnO2 composite oxide active component (this catalyst is prepared by co-precipitation method, the molar ratio of iron / manganese is 1:1, and the amount of catalyst used is 5% of the mass of cyanuric acid). Finally, 515.7 g of white powdered chlorobromoisocyanuric acid was obtained, with a purity of 93.8% and a yield of 85.1%.

[0056] Comparative Example 6 The preparation process and parameter control of chlorobromoisocyanuric acid in this comparative example are the same as in Example 1, except that the catalyst used is a Co3O4-MnO2 composite oxide catalyst (this catalyst is prepared by co-precipitation method, the molar ratio of cobalt / manganese is 1:1, and the amount of catalyst used is 5% of the mass of cyanuric acid). Finally, 499.3 g of white powdered chlorobromoisocyanuric acid was obtained, with a purity of 92.5% and a yield of 82.4%.

[0057] Comparative Example 7 The preparation process and parameter control of chlorobromoisocyanuric acid in this comparative example are the same as in Example 1, except that the catalyst used is a NiO-MnO2 composite oxide catalyst (this catalyst is prepared by co-precipitation method, the molar ratio of nickel / manganese is 1:1, and the amount of catalyst used is 5% of the mass of cyanuric acid). Finally, 499.3 g of white powdered chlorobromoisocyanuric acid was obtained, with a purity of 92.5% and a yield of 82.4%.

[0058] Comparative Example 8 The preparation process and parameter control of chlorobromoisocyanuric acid in this comparative example are the same as in Example 1, except that the catalyst used is a CuO-Fe2O3 composite oxide catalyst (this catalyst is prepared by co-precipitation method, the molar ratio of copper / iron is 1:1, and the amount of catalyst used is 5% of the mass of cyanuric acid). Finally, 532.1 g of white powdered chlorobromoisocyanuric acid was obtained, with a purity of 95.2% and a yield of 87.8%.

[0059] Comparative Example 9 The preparation process and parameter control of chlorobromoisocyanuric acid in this comparative example are the same as in Example 1, except that the catalyst used is a CuO-Co3O4 composite oxide catalyst (this catalyst is prepared by co-precipitation method, the molar ratio of copper / cobalt is 1:1, and the amount of catalyst used is 5% of the mass of cyanuric acid). Finally, 524.2 g of white powdered chlorobromoisocyanuric acid was obtained, with a purity of 94.7% and a yield of 86.5%.

[0060] Comparative Example 10 The preparation process and parameter control of chlorobromoisocyanuric acid in this comparative example are the same as in Example 1, except that the catalyst used is a CuO-NiO composite oxide catalyst (this catalyst is prepared by co-precipitation method, the molar ratio of copper / nickel is 1:1, and the amount of catalyst used is 5% of the mass of cyanuric acid). Finally, 534.5 g of white powdered chlorobromoisocyanuric acid was obtained, with a purity of 95.5% and a yield of 88.2%.

[0061] Example 2

[0062] Based on the preparation process of chlorobromoisocyanuric acid shown in Example 1, this example explores the effect of the copper / manganese ratio in the catalyst on the process. The process and parameter control in this example are the same as in Example 1, except that the molar ratio of copper / manganese in the catalyst is different. The reaction results are shown in Table 1.

[0063] Table 1

[0064] As can be seen from Table 1, in the preparation process of chlorobromoisocyanuric acid of the present invention, the molar ratio of copper to manganese in the copper-manganese bimetallic composite oxide catalyst can be selected as (0.1~10):1, preferably (0.25~4):1, further preferably (0.5~2):1, and even more preferably 1.5:1.

[0065] Example 3 A process for preparing chlorobromoisocyanuric acid includes the following steps: Step (1): Under inert gas protection, add the following to the reactor: 323g (2.5mol) cyanuric acid, 289g (2.8mol) sodium bromide, 15.8g CuO-MnO2 catalyst (5% of the mass of cyanuric acid), 5g sodium dodecylbenzenesulfonate, and 2000g deionized water (water:cyanuric acid mass ratio = 6:1). Stir at 15°C to form a uniform suspension. Note that the catalyst used in this example is the catalyst recovered from Example 1.

[0066] Step (2): Start by slowly adding 25% sodium hypochlorite solution (6 mol) and then adding appropriate dilute hydrochloric acid (10%) to maintain the pH at 5.5±0.2. Keep the reaction at this temperature for 1 hour.

[0067] Step (3): If the residual amount of cyanuric acid is <0.5%, heat to 50℃ and hot filter the reaction mixture to separate and recover the solid catalyst. Cool the filtrate to less than 5℃ and stir to crystallize for 1 hour. Filter and dry to obtain 582.4g of white powdered product chlorobromoisocyanuric acid with a purity of 98.3% and a yield of 96.1%. Recover the solid catalyst, wash the filter cake (catalyst) with a small amount of water, and dry it at 120℃ for 2 hours to obtain a solid catalyst that can be directly used in the next round of reaction.

[0068] Based on the catalyst shown in Example 1, this example explores a process for recycling the recovered catalyst multiple times. The results are shown in Table 2.

[0069] Table 2

[0070] Note: Activity retention rate = (yield of current batch / yield of first batch) × 100%.

[0071] As can be seen from Table 2, the copper-manganese bimetallic composite oxide catalyst used in this invention has a very simple recovery operation, good structural stability and recyclability, and can still maintain high catalytic activity after multiple cycles of recovery. The overall preparation process of chlorobromoisocyanuric acid in this invention is green and efficient, effectively reducing process costs.

[0072] Example 4 A process for preparing chlorobromoisocyanuric acid includes the following steps: Step (1): Under nitrogen protection, add the following to the reactor: 323 g (2.5 mol) of cyanuric acid, 238.0 g of potassium bromide (2.0 mol), 3.2 g of the CuO-MnO2 catalyst (copper / manganese molar ratio of 0.5:1, amount of which is 1% of the mass of cyanuric acid), 1.62 g of sodium laurate, and 969 g of deionized water (water:cyanuric acid mass ratio = 3:1). Stir at 10°C to form a uniform suspension.

[0073] Step (2): Start by slowly adding 10% sodium hypochlorite solution (3.75 mol) at a rate of 10 ml / min; add appropriate dilute hydrochloric acid (10%) to maintain the pH at 4.5 ± 0.2, and keep the reaction at the temperature for 0.5 h.

[0074] When the residual amount of cyanuric acid was detected to be <1.5%, the temperature was raised to 50°C to perform hot filtration of the reaction mixture, the solid catalyst was separated and recovered, the filtrate was cooled to less than 5°C, and stirred for crystallization for 1 hour; after filtration and drying, 516.3 g of white powdery product chlorobromoisocyanuric acid was obtained, with a purity of 92.5% and a yield of 85.2%.

[0075] Example 5 A process for preparing chlorobromoisocyanuric acid includes the following steps: Step (1): Under nitrogen protection, add the following to the reactor: 323 g (2.5 mol) of cyanuric acid, 192.9 g (1.875 mol) of sodium bromide, 223.1 g (1.875 mol) of potassium bromide, 32.3 g of the CuO-MnO2 catalyst (copper / manganese molar ratio of 2:1, amount of which is 10% of the mass of cyanuric acid), 16.15 g of sodium oleate, and 3230 g of deionized water (water:cyanuric acid mass ratio = 10:1). Stir at 25°C to form a uniform suspension.

[0076] Step (2): Start by slowly adding 30% sodium hypochlorite solution (6.25 mol) at a rate of 30 ml / min; add appropriate dilute hydrochloric acid (10%) to maintain the pH at 6.0 ± 0.2, and keep the reaction at this temperature for 5 h.

[0077] When the residual amount of cyanuric acid was detected to be <0.5%, the temperature was raised to 50°C to perform hot filtration of the reaction mixture, the solid catalyst was separated and recovered, the filtrate was cooled to less than 5°C, and stirred for crystallization for 2 hours; after filtration and drying, 572.7 g of white powder product chlorobromoisocyanuric acid was obtained, with a purity of 95.1% and a yield of 94.5%.

[0078] Example 6 The preparation process and parameter control of chlorobromoisocyanuric acid in this embodiment are the same as in Example 1. The difference is that the CuO-MnO2 composite catalyst used is prepared by impregnation method, and its preparation method is as follows: Weigh out manganese dioxide (MnO2, specific surface area ≥150m²). 2 12.0 g of copper nitrate (Cu(NO3)2·3H2O) was dispersed in 100 mL of deionized water and ultrasonically treated for 30 minutes to form a homogeneous slurry. Separately, 10.0 g of copper nitrate (Cu(NO3)2·3H2O) was dissolved in 50 mL of deionized water and slowly added to the above MnO2 slurry. The mixture was stirred and impregnated at 60 °C for 12 hours. Subsequently, the mixture was dried at 120 °C for 12 hours, then calcined in a muffle furnace at 400 °C for 4 hours (heating rate 2 °C / min). After natural cooling, it was ground through a 200-mesh sieve to obtain a black CuO-MnO2 composite oxide catalyst. The molar ratio of Cu to Mn in this catalyst was 1.5:1.

[0079] Step (1): Under nitrogen protection, add the following to the reactor: 323g (2.5mol) of cyanuric acid, 289g (2.8mol) of sodium bromide, 16.0g of the catalyst prepared by the above impregnation method (5% of the mass of cyanuric acid), 5g of sodium dodecylbenzenesulfonate, and 2000g of deionized water, and stir at 15°C to form a uniform suspension.

[0080] Step (2): Slowly add 25% sodium hypochlorite solution (containing 6.0 mol of available chlorine) at a rate of 20 mL / min, while adding 10% dilute hydrochloric acid to maintain the pH of the reaction system at 5.5 ± 0.2. After the addition is complete, continue to keep warm and age for 1 hour.

[0081] The residual amount of cyanuric acid was found to be <0.5%. The reaction mixture was heated to 50°C and hot filtered to recover the solid catalyst. The filtrate was cooled to <5°C, stirred and crystallized for 1 hour, filtered, and dried at 60°C. The preparation process in this embodiment finally yielded 580.2 g of white powdered product chlorobromoisocyanuric acid with a purity of 98.3% and a yield of 95.7%.

[0082] Example 7 The preparation process and parameter control of chlorobromoisocyanuric acid in this embodiment are the same as in Example 1. The difference is that the CuO-MnO2 composite catalyst used is prepared by mechanical mixing, and its preparation method is as follows: 8.5 g of analytical grade copper oxide (CuO) and 7.5 g of manganese dioxide (MnO2, chemically pure) were weighed out and placed in an agate mortar. They were then thoroughly ground and mixed at room temperature for 60 minutes until the powder was uniform in color and showed no significant color difference. The resulting mixture was dried at 120°C for 2 hours to remove adsorbed water, yielding the CuO-MnO2 mechanically mixed catalyst. The molar ratio of Cu to Mn in this catalyst was 1.5:1.

[0083] Step (1): Under nitrogen protection, add the following to the reactor: 323g (2.5mol) of cyanuric acid, 289g (2.8mol) of sodium bromide, 16.0g of the catalyst prepared by mechanical mixing catalyst (5% of the mass of cyanuric acid), 5g of sodium laurate, and 2000g of deionized water. Stir at 15°C to form a uniform suspension.

[0084] Step (2): Slowly add 25% sodium hypochlorite solution (containing 6.0 mol of available chlorine) at a rate of 20 mL / min, while adding 10% dilute hydrochloric acid to maintain the pH of the reaction system at 5.5 ± 0.2. After the addition is complete, continue to keep warm and age for 1 hour.

[0085] The residual amount of cyanuric acid was detected to be <0.5%. The reaction mixture was heated to 50°C and hot filtered to recover the solid catalyst. The filtrate was cooled to <5°C, stirred and crystallized for 1 hour, filtered and dried at 60°C. The preparation process in this embodiment finally yielded 575.8g of white powdered product chlorobromoisocyanuric acid with a purity of 97.9% and a yield of 95.0%.

[0086] It should be noted that the above description is a further detailed explanation of the present invention in conjunction with specific embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple improvements can be made without departing from the concept of the present invention, and all such improvements should be considered to fall within the scope of protection of the present invention.

Claims

1. A process for preparing chlorobromoisocyanuric acid, characterized in that, The preparation process includes: cyanuric acid, bromide and sodium hypochlorite undergo a halogenation reaction under the action of a catalyst to obtain chlorobromoisocyanuric acid; wherein the catalyst is a copper-manganese bimetallic composite oxide.

2. The preparation process of chlorobromoisocyanuric acid according to claim 1, characterized in that, Based on metal elements, the molar ratio of copper to manganese in the catalyst is (0.1~10):1, preferably (0.25~4):1, and more preferably (0.5~2):1; And / or, the amount of the catalyst is 1% to 10% of the mass of the cyanuric acid, preferably 2% to 8%; And / or, the catalyst is prepared by co-precipitation, impregnation or mechanical mixing.

3. The preparation process of chlorobromoisocyanuric acid according to claim 1, characterized in that, The molar ratio of cyanuric acid, bromine in bromide, and chlorine in sodium hypochlorite is 1:(0.8~1.5):(1.5~2.5), preferably 1:(1.0~1.2):(1.8~2.2).

4. The preparation process of chlorobromoisocyanuric acid according to claim 1, characterized in that, The bromide is sodium bromide and / or potassium bromide.

5. The preparation process of chlorobromoisocyanuric acid according to claim 1, characterized in that, The reaction temperature of the preparation process is 10~25℃, and the pH value of the reaction system is 4.5~6.0; And / or, the preparation process is carried out under an inert atmosphere.

6. The preparation process of chlorobromoisocyanuric acid according to any one of claims 1-5, characterized in that, The preparation process includes the following steps: Step (1): Add the cyanuric acid, the bromide and the catalyst to water and mix to obtain a suspension; Step (2): Add the sodium hypochlorite solution dropwise to the suspension, and after the addition is complete, age the solution to obtain the chlorobromoisocyanuric acid.

7. The preparation process of chlorobromoisocyanuric acid according to claim 6, characterized in that, The mass ratio of cyanuric acid to water is 1:(3~10). And / or, the concentration of the sodium hypochlorite solution is 10%~30%, preferably 20%~25%; And / or, the dropping rate of the sodium hypochlorite solution is 10~30 mL / min; preferably 15~25 mL / min.

8. The preparation process of chlorobromoisocyanuric acid according to claim 6, characterized in that, The aging process is carried out at a temperature of 10~30℃ for a time of 0.5~5h, preferably 1~3h.

9. The preparation process of chlorobromoisocyanuric acid according to claim 6, characterized in that, Step (1) also includes adding a dispersant to the water; Preferably, the dispersant comprises at least one of sodium dodecylbenzenesulfonate, sodium laurate, and sodium oleate; Preferably, the amount of the dispersant added is 0.5% to 5% of the mass of the cyanuric acid, more preferably 1% to 3%.

10. The preparation process of chlorobromoisocyanuric acid according to claim 6, characterized in that, The preparation process also includes step (3): solid-liquid separation of the reacted materials to recover the catalyst, and the recovered catalyst can be recycled after washing.

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