A composite water dispersible granule containing sulfosulfuron, metribuzin and haloxyfop- r-methyl and a preparation process thereof

Abstract

This invention relates to a composite water-dispersible granule containing sulfadiazine, metribuzin, and haloxyfop-R-methyl, and its preparation method. The composite water-dispersible granule is prepared by mixing component A (sulfadiazine WG) and component B (a binary compound of metribuzin and haloxyfop-R-methyl WG). The total formulation contains 0.5%-5% sulfadiazine, 10%-30% metribuzin, 2%-8% haloxyfop-R-methyl, 10%-25% adjuvants, and fillers. The preparation process of this invention adopts a step-by-step method. First, component A and component B are prepared separately by wet sand milling and spray drying. Then, they are mixed, compounded, inspected, and packaged to obtain the finished product. This process fundamentally solves the problems of sulfadiazine degradation and metribuzin crystallization. The product meets all performance standards, the process is simple, easy to industrialize, environmentally friendly, safe, and has stable efficacy, demonstrating good application value.

Description

Technical Field

[0001] This invention belongs to the field of pesticide formulation technology, specifically relating to a water-dispersible granule containing sulfadiazine, metribuzin, and high-efficiency flupyridine and its preparation process, and particularly to a composite water-dispersible granule preparation process that can solve the problems of sulfadiazine degradation and metribuzin crystallization. Background Technology

[0002] Sulfadiazon is a sulfonylurea herbicide characterized by high efficiency, broad spectrum, and low toxicity. It is mainly used to control various broadleaf weeds and some grass weeds in crops such as cornfields. However, its chemical properties are relatively sensitive, and its stability is poor. The sulfonylurea bridge bond (-SO2NHCONH-) in the molecular structure of sulfonylurea herbicides is the core unstable site, readily undergoing hydrolysis, photolysis, pyrolysis, and microbial degradation. It exhibits a strong pH dependence, being relatively stable in a neutral environment of pH 6–8. Under acidic conditions, the sulfonylurea bridge bond rapidly hydrolyzes and breaks, generating non-herbacterial sulfonamide and amino heterocycles. Degradation is even faster under strongly alkaline conditions. The hydrolysis half-life varies significantly with pH: only 0.3 days at pH=9, 4.6 days at pH=5, and 7.2 days at pH=7. In soil, the half-life ranges from 1.7 to 4.3 days. Mefenoxam is a triazinone herbicide that works by inhibiting weed photosynthesis. It is suitable for weed control in fields of crops such as soybeans and corn. It is a common herbicide that readily crystallizes. Its crystallization is mainly driven by two mechanisms: Ostwald ripening and crystal nucleation and aggregation. High temperature, temperature fluctuations, or insufficient adsorption capacity of the dispersant can accelerate crystallization. Phaloxyfop-R-methyl is an aryloxyphenoxypropionic acid herbicide, mainly used for controlling grassy weeds. When these three herbicides are used in combination, their mechanisms of action complement each other, broadening the spectrum of weed control, improving efficacy, reducing the dosage of single herbicides, and lowering the risk of weed resistance. Commonly formulated combinations can be used for post-emergence foliar application in potato fields, showing good control of annual weeds.

[0003] Currently, most commercially available formulations of sulfadiazine, metribuzin, and haloxyfop-R-methyl are oil-dispersible suspensions (OD). This formulation presents significant technical challenges in production, storage, and use: Firstly, sulfadiazine, in the oil phase of OD, is susceptible to degradation due to factors such as temperature, light, and adjuvants, leading to a decrease in the content of active ingredients and reduced herbicidal efficacy. It may also generate toxic and harmful degradation products, increasing environmental risks. Secondly, metribuzin, in the oil-phase dispersion system, is prone to crystal nucleation and aggregation due to temperature fluctuations, solvent evaporation, or system supersaturation, resulting in crystallization, formulation stratification, and precipitation. This affects the dispersibility and stability of the formulation, making it difficult to disperse evenly during use, thus affecting the uniformity of herbicidal effect. Furthermore, the crystallized particles may clog sprayer nozzles, causing inconvenience in field application.

[0004] Water-dispersible granules (WG) are an environmentally friendly pesticide formulation with advantages such as no dust, no solvent pollution, good stability, and ease of use. They also exhibit excellent dispersibility of the active ingredient and stable efficacy, making them one of the mainstream development directions for pesticide formulations. In existing technologies, directly mixing sulfosulfuron, metribuzin, and haloxyfop-R-methyl to prepare WG results in problems such as degradation of sulfosulfuron and decreased suspension rate due to the significant differences in their physicochemical properties, leading to interactions between sulfosulfuron and metribuzin / haloxyfop-R-methyl, thus failing to meet formulation quality requirements. Furthermore, existing preparation technologies for single-component sulfosulfuron WG or binary compound WG do not address the stability optimization when the three components are combined, thus failing to solve the aforementioned compounding challenges.

[0005] Existing patent CN106172460B discloses a compound herbicide composition containing sulfadiazine, haloxyfop-R-methyl, and metribuzin. The WG formulation is prepared using conventional air-jet milling methods, including mixing, ultra-fine air-jet milling, mixing, and granulation. However, this method does not address the degradation problem of sulfadiazine when the three components are combined. Patent CN106008461A discloses a method for preparing sulfadiazine crystal form A and its application in pesticide preparation. This method focuses solely on optimizing the crystal form of sulfadiazine alone, improving its solubility and viscosity by preparing a novel crystal form A, thus addressing the issue of degradation of sulfadiazine when the three components are combined. The patent addresses the issue of spray residue in technical grade herbicides, but it doesn't cover the compounding technology of sulfadiazine with metribuzin and haloxyfop-R-methyl, nor does it solve the degradation and crystallization problems when these three are compounded, making it unsuitable for the production requirements of compound formulations. Patent CN103931625B discloses a binary compound herbicidal composition containing metribuzin and haloxyfop-R-methyl, but it doesn't introduce sulfadiazine, nor does it optimize the formulation stability of the compound, nor does it cover the preparation process of water-dispersible granules. Furthermore, it cannot solve the degradation problem of sulfadiazine when compounded with these two herbicides; its technical solution is only applicable to binary compound systems and has significant limitations. In addition, none of the above patents disclose or optimize the preparation process, nor do they consider the interactions when three active ingredients with significantly different physicochemical properties are compounded, failing to fundamentally solve the core problems of sulfadiazine degradation and metribuzin crystallization.

[0006] Therefore, developing a preparation process that can simultaneously solve the degradation of sulfadiazine and the crystallization of metribuzin, and can stably produce sulfadiazine-metribuzin-high-efficiency flupyridine compound water-dispersible granules that fully meet the technical standards, is a technical bottleneck that urgently needs to be overcome in the field of pesticide formulation. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides a method for preparing a compound water-dispersible granule containing sulfadiazine, metribuzin, and high-efficiency flupyrflupyr. First, a single active ingredient (WG) and a binary compound WG formulation are prepared using a stepwise method, followed by mixing and compounding. This avoids direct contact between the three active ingredients during preparation, fundamentally solving the problems of sulfadiazine degradation and metribuzin crystallization, while ensuring that all formulation indicators meet requirements, thus improving formulation stability and herbicidal efficacy.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] This invention provides a composite water-dispersible granule containing sulfadiazine, cypermethrin, and high-efficiency flupyridine, wherein the preparation of the composite water-dispersible granule includes the following steps:

[0010] Step 1: Preparation of component A (sulfonylsulfuron WG)

[0011] According to the formula ratio of component A, weigh out the technical grade of sulfadiazine, adjuvants, fillers and water, put them into a sand mill for wet sand milling, cool and filter to obtain sulfadiazine slurry, dry and sieve to obtain component A;

[0012] Step 2: Preparation of component B (a compound formulation of quinclorac and flupyridine in WG form)

[0013] According to the formulation ratio of component B, weigh out the technical grade of cypermethrin, the technical grade of flupyradifurone, adjuvants, fillers and water, put them into a sand mill for wet sand milling, cool and filter to obtain slurry of cypermethrin and flupyradifurone, dry and sieve to obtain component B.

[0014] Step 3: Mixing and compounding

[0015] Weigh component A prepared in step 1 and component B prepared in step 2, put them into a mixer and mix until uniform to obtain the target composite water-dispersible granules.

[0016] Component A is sulfadiazine water-dispersible granules, and its composition by mass percentage is: sulfadiazine 0.5%-25%, adjuvants 10%-25%, and filler to 100%.

[0017] Component B is a binary compound water-dispersible granule of cypermethrin and high-efficiency flupyridine, and its composition by mass percentage is: 10%-45% cypermethrin, 2%-20% high-efficiency flupyridine, 10%-25% adjuvants, and filler to make up to 100%.

[0018] The total formulation of this composite water-dispersible granules consists of: 0.5%-5% sulfadiazine, 10%-30% cypermethrin, 2%-8% high-efficiency flupyridine, 10%-25% adjuvants, and filler to 100%.

[0019] Furthermore, this formulation is made by mixing component A and component B. The total formulation composition of each component by mass percentage is as follows: sulfadiazine 0.5%-5%, cypermethrin 10%-30%, high-efficiency flupyridine 2%-8%, adjuvants 10%-25%, and filler to 100%.

[0020] Furthermore, the preferred proportions of each active ingredient in the total formula are as follows: the content of sulfadiazine is preferably 1%-3%, the content of cypermethrin is preferably 19%-30%, and the content of haloxyfop-methyl is preferably 4%-6%.

[0021] Furthermore, the preferred proportions of each active ingredient in the total formula are as follows: sulfadiazine is preferably 1.2%, cypermethrin is preferably 19.8%, and haloxyfop-R-methyl is preferably 4%.

[0022] Furthermore, the additives include dispersants and wetting agents, and may selectively include one or more of binders and anti-caking agents; the dispersant is selected from one or more of polycarboxylates, lignin sulfonates, sulfonates, and polynaphthalene sulfonate anions, and the addition amount is 5%-15% of the total formulation mass; the wetting agent is selected from one or more of sulfonates, alkyl sulfates, and nonionic surfactants, and the addition amount is 2%-5% of the total formulation mass; the binder is selected from one or more of starch, sodium carboxymethyl cellulose, polyvinyl alcohol, polyethylene glycol, and dextrin, and the addition amount is 0.5%-3% of the total formulation mass; the anti-caking agent is selected from one or two of silica and talc, and the addition amount is 0.5%-2% of the total formulation mass.

[0023] Furthermore, the filler is selected from one or more of kaolin, corn starch, precipitated barium sulfate, inert clay, and expanded perlite, preferably kaolin or precipitated barium sulfate used alone or in combination.

[0024] Furthermore, in steps 1 and 2, the parameters for the wet sand milling are as follows: a horizontal sand mill is selected, the sand milling speed is 1500-3000 r / min, the sand milling time is 20-60 min, the sand milling medium is 0.1-0.3 mm zirconium beads, the slurry solid content is 30%-50%, the particle size of the slurry after sand milling is D90=3μm-10μm, and the slurry temperature is controlled not to exceed 40℃ during the sand milling process; the parameters for the spray drying are as follows: a centrifugal or pressure atomizer is selected for the spray dryer, the inlet air temperature is 100℃-160℃, the outlet air temperature is 60℃-90℃, the feed rate is 10-30 L / h, the atomization pressure is 0.2-0.5 MPa, and the hot air velocity is 1.5-3.0 m / s. Optionally, a wet negative pressure mixing, negative pressure sand milling, and negative pressure spray drying process is adopted, and the negative pressure value of the mixing chamber, sand milling chamber, and spray drying chamber is not less than -0.2 atmospheres.

[0025] Furthermore, in step 3, the stirring speed of the mixer is 800-1500 r / min, and the mixing time is preferably 3 min-10 min to ensure that component A and component B are fully mixed.

[0026] Compared with the prior art, the advantages of the present invention are as follows:

[0027] 1. Fundamentally solves the technical pain points of existing OD formulations: This invention abandons the traditional OD formulation and adopts the environmentally friendly WG formulation. By optimizing the selection of adjuvants and the particle size of the powder, it inhibits the Ostwald ripening and crystal nucleation and aggregation of metribuzin, completely solving the problem of metribuzin crystallization, significantly improving the storage stability and usage stability of the formulation, and extending the shelf life of the formulation.

[0028] 2. Overcoming the degradation problem of sulfadiazine: The water-dispersible granules prepared by the spray drying molding process of this invention are hollow spherical porous particles. During the high-temperature atomization drying molding process, dispersants, wetting agents and other additives can preferentially and uniformly adsorb onto the surface of the active ingredient particles to form a dense and stable polymer protective layer, which significantly improves the physical and chemical stability of the single agent system. Meanwhile, this invention employs a stepwise independent granulation process, preparing the sensitive and easily degradable sulfadiazine as component A solid particles separately, and preparing component B solid particles by compounding cypermethrin and high-efficiency flupyradifurone. Before molding, the two systems are completely isolated and do not come into contact with each other, thus completely avoiding the chemical incompatibility reaction caused by the long-term coexistence and contact of sulfadiazine with cypermethrin and high-efficiency flupyradifurone from the source of the process. This fundamentally solves the technical problems of sulfadiazine degradation during storage, continuous decline in system suspension rate, and decline in efficacy. Compared with conventional one-step mixed granulation water-dispersible granules, this invention adopts a continuous process of air jet milling, wet mixing, extrusion granulation, and overall drying. The three active ingredients with very different physicochemical properties continue to coexist and come into contact throughout the entire process of raw material mixing, slurry storage, granulation, and drying. There is always interaction between components within the system, which ultimately leads to poor thermal storage stability of the finished product, a significant reduction in suspension rate, and a significant decline in formulation performance. The stability defects cannot be compensated for by conventional adjuvant adjustments.

[0029] 3. All indicators of the formulation meet industry standards: By optimizing the formulation composition (especially the selection and ratio of adjuvants) and preparation process parameters, the composite water-dispersible granules prepared by this invention meet all technical requirements. They have good dispersibility, suspension, wetting properties and disintegration properties. When used, they can be quickly dispersed in water to form a uniform and stable suspension. The spray is uniform, which improves the weeding effect. Moreover, there is no dust or solvent pollution, so it is safe and environmentally friendly to use. At the same time, it reduces dust spillage during the production process and protects the occupational health of operators.

[0030] 4. Stable efficacy, long-lasting effect, and good synergistic effect: The compound water-dispersible granules prepared by this invention have high stability of active ingredients, are not easily degraded or crystallized, and can maintain efficacy for a long time. Moreover, the three active ingredients, sulfadiazine, metribuzin, and haloxyfop-R-methyl, have complementary mechanisms of action, broad spectrum of weed control, and significantly better weed control effect than existing OD formulations. At the same time, it reduces the dosage, reduces the risk of weed resistance and environmental pressure, and is suitable for weed control needs in various crop fields such as potato fields and corn fields. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to specific embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0032] Example 1

[0033] A composite water-dispersible granule containing sulfadiazine, metribuzin, and high-efficiency flupyridine, the total formula by mass percentage is as follows: sulfadiazine 1.2%, metribuzin 19.8%, high-efficiency flupyridine 4%, dispersant GY-DOS (polycarboxylate) 4%, dispersant Ultrazine NA (sodium lignin flavonoid) 6%, wetting agent MORWET EFW (sulfonate) 3%, anti-caking agent (silica) 1%, and filler (kaolin: precipitated barium sulfate = 1:2) to make up to 100%.

[0034] The preparation process is as follows:

[0035] Step 1: Preparation of component A (sulfonylsulfuron WG)

[0036] According to the formulation of component A, weigh out 12% sulfadiazine, 4% dispersant GY-DOS (polycarboxylate), 6% dispersant Ultrazine NA (sodium lignin flavonoid), 3% wetting agent MORWET EFW (sulfonate), 1% anti-caking agent (silica), and filler (kaolin: precipitated barium sulfate = 1:2) to make up to 100%. Add an appropriate amount of deionized water to control the solid content to 50%. After high-speed shearing, feed it into a sand mill for wet sand milling at a speed of 2000 r / min for 40 min. After sand milling, the particle size of the slurry is D90 = 6.85 μm. After cooling to 30℃, the slurry is filtered through a 200-mesh filter. The filtered slurry is then sent to a spray dryer for drying. The inlet air temperature is 130℃, the outlet air temperature is 72℃, the feed rate is 12L / h, the atomization pressure is 0.25MPa, and the hot air velocity is 1.8m / s. After drying, the particles are passed through a 30-200 mesh sieve to obtain component A, which is then set aside (all percentages are by mass, the same below).

[0037] Step 2: Preparation of component B (a compound formulation of quinclorac and flupyridine in WG form)

[0038] According to the formulation of component B, weigh out 22% of haloxyfop-R-methyl, 4.45% of high-efficiency flupyridine, 4% of dispersant GY-DOS (polycarboxylate), 6% of dispersant Ultrazine NA (sodium lignin flavonoid), 3% of wetting agent MORWET EFW (sulfonate), 1% of anti-caking agent (silica), and filler (kaolin: precipitated barium sulfate = 1:2) to make up to 100%. After high-speed shearing, feed it into a sand mill for wet sand milling at a speed of 2000 r / min for 30 min. After sand milling, the particle size of the slurry D90 is 6.20 μm. After cooling to 30℃, the slurry is filtered through a 200-mesh filter. The filtered slurry is then sent to a spray dryer for drying. The inlet air temperature is 130℃, the outlet air temperature is 70℃, the feed rate is 12L / h, the atomization pressure is 0.25MPa, and the hot air velocity is 1.8m / s. After drying, the particles are passed through a 30-200 mesh sieve to obtain component B, which is then set aside for later use.

[0039] Step 3: Mixing and compounding

[0040] Weigh 50g (10%) of component A and 450g (90%) of component B, put them into a mixer, and mix at 800r / min for 10min to obtain a compound water-dispersible granule containing 1.2% sulfadiazine, 19.8% cypermethrin, and 4% high-efficiency flupyridine.

[0041] Step 4: Inspection and Packaging

[0042] The above products were tested for various indicators, and the results are as follows: moisture 1.8%, pH value 7.88, wet sieve test (passing through a 75μm sieve) 99%, dispersibility 95%, suspension rate 98%, wetting time 15s, persistent foaming (foam volume after 1 min) 10mL, abrasion resistance 94%, dust 22mg. After heat storage (54℃±2℃, 14 days), all indicators meet the requirements of conventional water-dispersible granules, and there is no degradation of sulfadiazine and no crystallization of cypermethrin.

[0043] Example 2

[0044] A composite water-dispersible granule containing sulfadiazine, metribuzin, and haloxyfop-R-methyl, the total formula by mass percentage is as follows: sulfadiazine 2.0%, metribuzin 25.0%, haloxyfop-R-methyl 5.0%, dispersant Borresperse NA (lignin sulfonate) 9%, dispersant Morwet D-425 (sulfonate) 6%, wetting agent Win1187 (alkyl sulfate) 2%, and filler (precipitated barium sulfate) to make up to 100%.

[0045] The preparation process is as follows:

[0046] Step 1: Preparation of component A (sulfonylsulfuron WG)

[0047] According to the formulation of component A, weigh out 25% sulfadiazine, 9% dispersant Borresperse NA (lignin sulfonate), 6% dispersant Morwet D-425 (sulfonate), 2% wetting agent Win1187 (alkyl sulfate), and filler (precipitated barium sulfate) to make up to 100%. Add an appropriate amount of deionized water to control the solid content to 45%. After high-speed shearing, feed the mixture into a sand mill for wet sand milling at a speed of 1500 r / min for 60 min. The particle size of the slurry after sand milling is D90 = 3.52 μm. After cooling to 30℃, filter the mixture through a 200-mesh filter. Send the filtered slurry to a spray dryer for drying. The inlet air temperature is 145℃, the outlet air temperature is 79℃, the feed rate is 20 L / h, the atomization pressure is 0.35 MPa, and the hot air velocity is 2.4 m / s. After drying, the particles pass through a 30-200 mesh sieve to obtain component A, which is then set aside.

[0048] Step 2: Preparation of component B (a compound formulation of quinclorac and flupyridine in WG form)

[0049] According to the formulation of component B, weigh out 27.2% of haloxyfop-R-methyl, 5.45% of high-efficiency flupyradifurone, 9% of dispersant Borresperse NA (lignin sulfonate), 6% of dispersant Morwet D-425 (sulfonate), 2% of wetting agent Win1187 (alkyl sulfate), and filler (precipitated barium sulfate) to make up to 100%. Add an appropriate amount of deionized water to control the solid content to 45%. After high-speed shearing, feed it into a sand mill for wet sand milling at a speed of 1500 r / min for 60 min. After sand milling, the particle size of the slurry is D90=3.33μm. After cooling to 30℃, the slurry is filtered through a 200-mesh filter. The filtered slurry is then sent to a spray dryer for drying. The inlet air temperature is 145℃, the outlet air temperature is 78℃, the feed rate is 20L / h, the atomization pressure is 0.35MPa, and the hot air velocity is 2.4m / s. After drying, the particles are passed through a 30-200 mesh sieve to obtain component B, which is then set aside.

[0050] Step 3: Mixing and compounding

[0051] Weigh 40g (8%) of component A and 460g (92%) of component B, put them into a mixer, and mix at 1200r / min for 6min to obtain a compound water-dispersible granule containing 2.0% sulfadiazine, 25.0% cypermethrin, and 5.0% high-efficiency flupyridine.

[0052] Step 4: Inspection and Packaging

[0053] The above products were tested for various indicators, and the results are as follows: moisture 1.62%, pH value 7.58, wet sieve test (passing through a 75μm sieve) 99%, dispersibility 96%, suspension rate 100%, wetting time 10s, persistent foaming (foam volume after 1 min) 28mL, abrasion resistance 92%, dust 5mg. After heat storage (54℃±2℃, 14 days), all indicators meet the requirements of conventional water-dispersible granules, and there is no degradation of sulfadiazine and no crystallization of cypermethrin.

[0054] Example 3

[0055] A composite water-dispersible granule containing sulfadiazine, metribuzin, and high-efficiency flupyridine, the total formula by mass percentage is as follows: sulfadiazine 3%, metribuzin 30.0%, high-efficiency flupyridine 6.0%, dispersant NNO (naphthalene sulfonate formaldehyde condensate) 8%, dispersant TERSPERSE 2700 (polycarboxylate) 3%, wetting agent SP-DF2209 (nonionic surfactant) 5%, binder (polyvinyl alcohol) 2%, anti-caking agent (silica: talc = 1:1) 1.5%, and filler (kaolin) to make up to 100%.

[0056] The preparation process is as follows:

[0057] Step 1: Preparation of component A (sulfonylsulfuron WG)

[0058] According to the formulation of component A, weigh out 15% sulfadiazine, 8% dispersant NNO (naphthalene sulfonate formaldehyde condensate), 3% dispersant TERSPERSE 2700 (polycarboxylate), 5% wetting agent SP-DF2209 (nonionic surfactant), 2% binder (polyvinyl alcohol), 1.5% anti-caking agent (silica: talc = 1:1), and filler (kaolin) to make up to 100%. Add an appropriate amount of deionized water to control the solid content to 40%. After high-speed shearing, feed it into a sand mill for wet sand milling. The sand milling speed is 3000 r / min and the sand milling time is 30 min. After sand milling, the particle size of the slurry D90 is 4.66 μm. After cooling to 30℃, the slurry is filtered through a 200-mesh filter. The filtered slurry is then sent to a spray dryer for drying. The inlet air temperature is 160℃, the outlet air temperature is 88℃, the feed rate is 30L / h, the atomization pressure is 0.5MPa, and the hot air velocity is 3.0m / s. After drying, the particles are passed through a 30-200 mesh sieve to obtain component A, which is then set aside.

[0059] Step 2: Preparation of component B (a compound formulation of quinclorac and flupyridine in WG form)

[0060] According to the formulation of component B, weigh out 37.5% of haloxyfop-R-methyl, 7.5% of high-efficiency fluroxypyr, 8% of dispersant NNO (naphthalene sulfonate formaldehyde condensate), 3% of dispersant TERSPERSE 2700 (polycarboxylate), 5% of wetting agent SP-DF2209 (nonionic surfactant), 2% of binder (polyvinyl alcohol), 1.5% of anti-caking agent (silica: talc = 1:1), and filler (kaolin) to make up to 100%. Add an appropriate amount of deionized water to control the solid content to 40%. After high-speed shearing, feed it into a sand mill for wet sand milling. The sand milling speed is 3000 r / min and the sand milling time is 30 min. After sand milling, the particle size of the slurry D90 is 4.20 μm. After cooling to 30℃, the slurry is filtered through a 200-mesh filter. The filtered slurry is then sent to a spray dryer for drying. The inlet air temperature is 160℃, the outlet air temperature is 90℃, the feed rate is 30L / h, the atomization pressure is 0.5MPa, and the hot air velocity is 3.0m / s. After drying, the particles are passed through a 30-200 mesh sieve to obtain component B, which is then set aside for later use.

[0061] Step 3: Mixing and compounding

[0062] Weigh 100g (20%) of component A and 400g (80%) of component B, put them into a mixer, and mix at 1500r / min for 3min to obtain a compound water-dispersible granule containing 3.0% sulfadiazine, 30.0% cypermethrin, and 6.0% high-efficiency flupyridine.

[0063] Step 4: Inspection and Packaging

[0064] The above products were tested for various indicators, and the results are as follows: moisture 2.05%, pH value 8.2, wet sieve test (passing through a 75μm sieve) 99%, dispersibility 93%, suspension rate 98%, wetting time 25s, persistent foaming (foam volume after 1 min) 32mL, abrasion resistance 94%, dust 18mg. After heat storage (54℃±2℃, 14 days), all indicators meet the requirements of conventional water-dispersible granules, and there is no degradation of sulfadiazine and no crystallization of cypermethrin.

[0065] Comparative Example 1: Preparation process referenced CN106172460B

[0066] A composite water-dispersible granule containing sulfadiazine, metribuzin, and high-efficiency flupyridine, the total formula by mass percentage is as follows: sulfadiazine 1.2%, metribuzin 19.8%, high-efficiency flupyridine 4%, dispersant GY-DOS (polycarboxylate) 4%, dispersant Ultrazine NA (sodium lignin flavonoid) 6%, wetting agent MORWET EFW (sulfonate) 3%, anti-caking agent (silica) 1%, and filler (kaolin: precipitated barium sulfate = 1:2) to make up to 100%.

[0067] The preparation process is as follows:

[0068] The above raw materials were processed using conventional air jet milling methods to produce water-dispersible granules, namely, mixing, ultra-micro air jet milling, mixing, and granulation steps, to produce a composite water-dispersible granule containing 1.2% sulfadiazine, 19.8% cypermethrin, and 4% high-efficiency flupyridine.

[0069] Comparative Example 2: Component A was prepared by compounding sulfadiazine and highly effective flupyridine (WG).

[0070] A composite water-dispersible granule containing sulfadiazine, metribuzin, and high-efficiency flupyridine, the total formula by mass percentage is as follows: sulfadiazine 1.2%, metribuzin 19.8%, high-efficiency flupyridine 4%, dispersant GY-DOS (polycarboxylate) 4%, dispersant Ultrazine NA (sodium lignin flavonoid) 6%, wetting agent MORWET EFW (sulfonate) 3%, anti-caking agent (silica) 1%, and filler (kaolin: precipitated barium sulfate = 1:2) to make up to 100%.

[0071] The preparation process is as follows:

[0072] Step 1: Preparation of component A (sulfamethoxam and high-efficiency flupyridine compound WG)

[0073] According to the formulation of component A, weigh out 3% sulfadiazine, 10% high-efficiency flupyridine, 4% dispersant GY-DOS (polycarboxylate), 6% dispersant Ultrazine NA (sodium lignin flavonoid), 3% wetting agent MORWET EFW (sulfonate), 1% anti-caking agent (silica), and filler (kaolin: precipitated barium sulfate = 1:2) to make up to 100%. Add an appropriate amount of deionized water to control the solid content to 50%. After high-speed shearing, feed it into a sand mill for wet sand milling. The sand milling speed is 2000 r / min and the sand milling time is 40 min. After sand milling, the particle size of the slurry D90 is 6.85 μm. After cooling to 30℃, the slurry is filtered through a 200-mesh screen. The filtered slurry is then sent to a spray dryer for drying. The inlet air temperature is 130℃, the outlet air temperature is 72℃, the feed rate is 12L / h, the atomization pressure is 0.25MPa, and the hot air velocity is 1.8m / s. After drying, the particles are passed through a 30-200 mesh sieve to obtain component A, which is then set aside.

[0074] Step 2: Preparation of component B (methazine WG)

[0075] According to the formulation of component B, weigh out 33% of cypermethrin, 4% of dispersant GY-DOS (polycarboxylate), 6% of dispersant UltrazineNA (sodium lignin flavonoid), 3% of wetting agent MORWET EFW (sulfonate), 1% of anti-caking agent (silica), and filler (kaolin: precipitated barium sulfate = 1:2) to make up to 100%. After high-speed shearing, feed it into a sand mill for wet sand milling at a speed of 2000 r / min for 30 min. The particle size of the slurry after sand milling is D90 = 6.20 μm. After cooling to 30℃, filter it through a 200-mesh filter. The filtered slurry is then fed into a spray dryer for drying at an inlet air temperature of 130℃, an outlet air temperature of 70℃, a feed rate of 12 L / h, an atomization pressure of 0.25 MPa, and a hot air velocity of 1.8 m / s. After drying, the particles pass through a 30-200 mesh sieve to obtain component B, which is then set aside.

[0076] Step 3: Mixing and compounding

[0077] Weigh 200g (40%) of component A and 300g (60%) of component B, put them into a mixer, and mix at 800r / min for 10min to obtain a water-dispersible granule containing 1.2% sulfadiazine, 19.8% cypermethrin, and 4% high-efficiency flupyridine.

[0078] Comparative Example 3: Component A was prepared by combining sulfadiazine and metribuzin (WG).

[0079] A composite water-dispersible granule containing sulfadiazine, metribuzin, and high-efficiency flupyridine, the total formula by mass percentage is as follows: sulfadiazine 1.2%, metribuzin 19.8%, high-efficiency flupyridine 4%, dispersant GY-DOS (polycarboxylate) 4%, dispersant Ultrazine NA (sodium lignin flavonoid) 6%, wetting agent MORWET EFW (sulfonate) 3%, anti-caking agent (silica) 1%, and filler (kaolin: precipitated barium sulfate = 1:2) to make up to 100%.

[0080] The preparation process is as follows:

[0081] Step 1: Preparation of component A (sulfamethoxam and metribuzin compound WG)

[0082] According to the formulation of component A, weigh out 2% sulfadiazine, 33% metribuzin, 4% dispersant GY-DOS (polycarboxylate), 6% dispersant Ultrazine NA (sodium lignin flavonoid), 3% wetting agent MORWET EFW (sulfonate), 1% anti-caking agent (silica), and filler (kaolin: precipitated barium sulfate = 1:2) to make up to 100%. Add an appropriate amount of deionized water to control the solid content to 50%. After high-speed shearing, feed it into a sand mill for wet sand milling at a speed of 2000 r / min for 40 min. After sand milling, the particle size of the slurry is D90 = 6.85 μm. After cooling to 30℃, the slurry is filtered through a 200-mesh screen. The filtered slurry is then sent to a spray dryer for drying. The inlet air temperature is 130℃, the outlet air temperature is 72℃, the feed rate is 12L / h, the atomization pressure is 0.25MPa, and the hot air velocity is 1.8m / s. After drying, the particles are passed through a 30-200 mesh sieve to obtain component A, which is then set aside.

[0083] Step 2: Preparation of component B (high-efficiency flupyradifurone WG)

[0084] According to the formulation of component B, weigh out 10% of high-efficiency fluopyram, 4% of dispersant GY-DOS (polycarboxylate), 6% of dispersant Ultrazine NA (sodium lignin flavonoid), 3% of wetting agent MORWET EFW (sulfonate), 1% of anti-caking agent (silica), and filler (kaolin: precipitated barium sulfate = 1:2) to make up to 100%. After high-speed shearing, feed it into a sand mill for wet sand milling at a speed of 2000 r / min for 30 min. The particle size of the slurry after sand milling is D90 = 6.20 μm. After cooling to 30℃, filter it through a 200-mesh filter. The filtered slurry is then fed into a spray dryer for drying at an inlet air temperature of 130℃, an outlet air temperature of 70℃, a feed rate of 12 L / h, an atomization pressure of 0.25 MPa, and a hot air velocity of 1.8 m / s. After drying, the particles pass through a 30-200 mesh sieve to obtain component B, which is then set aside.

[0085] Step 3: Mixing and compounding

[0086] Weigh 300g (60%) of component A and 200g (40%) of component B, put them into a mixer, and mix at 800r / min for 10min to obtain a compound water-dispersible granule containing 1.2% sulfadiazine, 19.8% cypermethrin, and 4% high-efficiency flupyridine.

[0087] Performance testing

[0088] Test reagents: The composite water-dispersible granules prepared in Examples 1-3 and Comparative Examples 1-3 of this invention were combined with existing OD formulations containing sulfadiazine, cypermethrin, and high-efficiency flupyridine (Sample 2, active ingredient ratio 1.0%:18.0%:5.0%, purchased from Henan Hans Market).

[0089] Test method: According to NY / T 3581-2020 and GB 28139-2011 standards, a stability comparison test was conducted by constant temperature heat storage at 54℃±2℃ for 14 days. The changes in the content of effective components before and after storage and whether crystallization occurred were detected, as well as the changes in suspension rate before and after heat storage.

[0090] The results are shown in the table below: Example 1 1.21 1.20 0.86 no 98 Example 2 2.02 2.02 0 no 99 Example 3 3.05 3.03 0.66 no 99 Existing sample 2 0.96 0.62 35.4 yes 63 Comparative Example 1 1.20 0.96 20 no 82 Comparative Example 2 1.22 1.11 9.02 no 88 Comparative Example 3 1.21 1.02 15.7 no 79

[0091] The results of the above comparative experiments show that the degradation rate of sulfadiazine granules prepared by the present invention is significantly lower than that of the existing sample 2 (OD formulation) and the formulations prepared by comparative examples 1, 2 and 3. Furthermore, there is no crystallization of sulfadiazine, and the suspension rate after heat storage is also significantly higher than that of the comparative examples. This fully demonstrates that the technical solution of the present invention can effectively solve the pain points of the existing technology and improve the stability and performance of the formulation. Furthermore, testing revealed that the product's various indicators, including active ingredient content, moisture content, pH value, wet sieve test, dispersibility, suspension rate, wetting time, persistent foaming, abrasion resistance, dust content, and thermal storage stability, all met the conventional technical requirements for water-dispersible granules. Specifically: moisture ≤3.0%, pH value 7.0-10.0, wet sieve test (passing through a 75μm sieve) ≥98%, dispersibility ≥80%, suspension rate ≥80%, wetting time ≤60s, persistent foaming (foam volume after 1 min) ≤60mL, abrasion resistance ≥90%, dust ≤30mg. After thermal storage (54℃±2℃, 14 days), the mass fraction of each active ingredient was not less than 95% of that before thermal storage, and there was no crystallization of cypermethrin. Other indicators also met the relevant standards such as NY / T 3581-2020 and GB 28139-2011. It is suitable for industrial production and field use.

Claims

1. A composite water dispersible granule containing sulfosulfuron, metribuzin and flumipropyn, characterized in that, The preparation of the composite water-dispersible granules includes the following steps: Step 1: Preparation of component A (sulfonylsulfuron WG) According to the formula ratio of component A, weigh out the technical grade of sulfadiazine, adjuvants, fillers and water, put them into a sand mill for wet sand milling, cool and filter to obtain sulfadiazine slurry, dry and sieve to obtain component A; Step 2: Preparation of component B (a compound formulation of quinclorac and flupyridine in WG form) According to the formulation ratio of component B, weigh out the technical grade of cypermethrin, the technical grade of flupyradifurone, adjuvants, fillers and water, put them into a sand mill for wet sand milling, cool and filter to obtain slurry of cypermethrin and flupyradifurone, dry and sieve to obtain component B. Step 3: Mixing and compounding Weigh component A prepared in step 1 and component B prepared in step 2, put them into a mixer and mix until uniform to obtain the target composite water-dispersible granules; Component A is sulfadiazine water-dispersible granules, and its composition by mass percentage is: sulfadiazine 0.5%-25%, adjuvants 10%-25%, and filler to 100%; Component B is a binary compound water-dispersible granule of cypermethrin and high-efficiency flupyridine, and its composition by mass percentage is: cypermethrin 10%-45%, high-efficiency flupyridine 2%-20%, adjuvants 10%-25%, and filler to 100%; The total formulation of this composite water-dispersible granules consists of: 0.5%-5% sulfadiazine, 10%-30% cypermethrin, 2%-8% high-efficiency flupyridine, 10%-25% adjuvants, and filler to 100%.

2. The composite water dispersible granule according to claim 1, characterized in that, The proportions of each active ingredient in the total formula are as follows: sulfadiazine 1%-3%, cypermethrin 19%-30%, and haloxyfop-methyl 4%-6%.

3. The composite water dispersible granule according to claim 1, characterized in that, The proportions of each active ingredient in the total formula are as follows: sulfadiazine 1.2%, cypermethrin 19.8%, and haloxyfop-R-methyl 4%.

4. The composite water dispersible granule according to claim 1, characterized in that, The additives include dispersants and wetting agents, and may also selectively include one or more of binders and anti-caking agents; The dispersant is selected from one or more of polycarboxylates, lignin sulfonates, sulfonates, and polynaphthalene sulfonate anions, and the amount added is 5%-15% of the total formulation mass; The wetting agent is selected from one or more of sulfonates, alkyl sulfates, and nonionic surfactants, and the amount added is 2%-5% of the total formulation mass; The binder is selected from one or more of starch, sodium carboxymethyl cellulose, polyvinyl alcohol, polyethylene glycol, and dextrin, and the amount added is 0.5%-3% of the total formula mass; The anti-caking agent is selected from one or two of silica and talc, and the amount added is 0.5%-2% of the total formula mass.

5. The composite water dispersible granule according to claim 1, characterized in that, The filler is selected from one or more of kaolin, corn starch, precipitated barium sulfate, inert clay, and expanded perlite, preferably kaolin or precipitated barium sulfate used alone or in combination.

6. The composite water dispersible granule according to claim 1, characterized in that, In steps 1 and 2, the parameters for wet sand milling are as follows: a horizontal sand mill is selected, the sand milling speed is 1500-3000 r / min, the sand milling time is 20-60 min, the sand milling medium is 0.1-0.3 mm zirconium beads, the slurry solid content is 30%-50%, the particle size of the slurry after sand milling is D90=3μm-10μm, and the slurry temperature is controlled not to exceed 40℃ during the sand milling process; the parameters for spray drying are as follows: a centrifugal or pressure atomizer is selected for the spray dryer, the inlet air temperature is 100℃-160℃, the outlet air temperature is 60℃-90℃, the feed rate is 10-30 L / h, the atomization pressure is 0.2-0.5 MPa, and the hot air velocity is 1.5-3.0 m / s.

7. The composite water dispersible granule according to claim 1, wherein In step 3, a wet negative pressure mixing, negative pressure sand milling, and negative pressure spray drying process is adopted, and the negative pressure values ​​of the mixing chamber, sand milling chamber, and spray drying chamber are not less than -0.2 atmospheres.

8. The composite water dispersible granule according to claim 1, characterized in that, In step 3, the stirring speed of the mixer is 800-1500 r / min, and the mixing time is 3 min-10 min.