Zinc thiazole / kaempferol nanosuspension dispersion

Abstract

The present invention belongs to the field of nano-pesticide, in particular to the preparation of a pesticide which is insoluble in water and solvent, and the particle size of which is less than 100 nanometers. The 100 nanometer or less level of thiazole zinc / kaempferol nanometer suspension dispersion liquid is formed by mixing two or three components with water dilution.

Description

Thiazole zinc / kasugamycin nanosuspension dispersion

Technical field

[0001] The present invention belongs to the field of nano pesticides, and particularly relates to a pesticide variety insoluble in water and solvent and a compounding system thereof, and the preparation of a suspension dispersion with particle size less than 100 nanometers. [Background Technology]

[0002] Modern agricultural production requires the use of pesticides. Improving the formulation performance of existing pesticides, increasing their efficacy, reducing their dosage, and mitigating their impact on the environment are of great significance to the sustainable development of agriculture.

[0003] An effective way to reduce pesticide use is to effectively reduce the particle size of the active ingredients in pesticide formulations. For water-insoluble pesticides, the minimum size is a few nanometers. Nanopesticides refer to formulations in which the pesticide particles are on the nanometer scale (1 to 100 nm). The particle size of traditional pesticide formulations is on the micrometer scale, ranging from a few microns to tens of microns or even larger. If the particle size is reduced to nanometers, the size is reduced by a thousand times. Theoretically, the number of particles can increase by a billion times, and the surface area can increase by a thousand times. The dramatic increase in the number and surface area of ​​pesticide particles allows for more extensive contact with the target, allowing the efficacy to be fully exerted and improved.

[0004] On April 1, 2019, the International Union of Pure and Applied Chemistry (IUPAC), celebrating its 100th anniversary, announced its "Top 10 Chemical Inventions That Will Change the World," with nanopesticides topping the list. This is due to the growing global population, projected to approach 10 billion by 2050. Feeding this large population requires a significant increase in agricultural output while minimizing the environmental impact of land use, including reducing pesticide pollution and water consumption. Nanopesticides, with their small particle size and improved target absorption, offer a promising tool for addressing the key challenges of traditional pesticides: environmental pollution, pesticide accumulation in organisms, and the significant increase in pest and disease resistance. While nanopesticides are by no means the only path to sustainable agricultural development, they certainly offer a lower impact on the environment and human health, contributing to a more sustainable future for the planet.

[0005] Thiazole zinc, chemical name is 2-amino-5-mercapto-1,3,4-thiadiazole zinc, chemical formula is C4H4N6S4Zn, relative molecular mass is 329.8, off-white powder, melting point >300℃. It is insoluble in water and organic solvents, decomposes when exposed to alkali, and is stable under neutral and weak alkaline conditions. Thiazole zinc is a zinc-containing heterocyclic fungicide developed in China. It is effective against bacterial diseases and highly effective against a variety of fungal diseases. It can be used to prevent and control crop diseases. The molecular structure of thiazole zinc is composed of two groups. One is the thiazole group, which has no inhibitory effect on bacteria outside the plant body, but is an efficient therapeutic agent in the plant body. The drug causes serious damage to the bacteria in the plant's pore vessels, and its cell wall becomes thinner and then disintegrates, leading to the death of the bacteria. Second, zinc ions have both fungicidal and bactericidal effects. The zinc ions in the agent react with the cations (H + , K + The zinc ions exchange with the zinc ions (e.g., zinc ions in the cell membrane) to cause protein coagulation, thereby killing the bacteria. Some zinc ions penetrate into the pathogen's cells and bind to certain enzymes, affecting their activity, leading to dysfunction, exhaustion, and death. Therefore, the combined action of these two groups in zinc thiazole is highly effective in preventing and controlling pathogens, and its target is wide.

[0006] Thiazole zinc can control the following crops and targets: Cabbage: soft rot bacterial diseases, black spot, anthracnose, rust, powdery mildew, and zinc deficiency aging. Peanuts: bacterial wilt, dead stem and root rot, and leaf spot. Rice: stunted seedlings, yellowing and rotting seedlings, bacterial leaf streak, bacterial leaf blight, sheath blight, blast, and zinc deficiency seedling burn. Cucumbers: bacterial angular leaf spot, canker, downy mildew, yellow spot, and zinc deficiency yellowing. Tomatoes: bacterial canker, late blight, brown spot, anthracnose, and zinc deficiency leaflet.

[0007] The zinc ion in zinc thiazole has coordination properties, so the zinc thiazole molecule exhibits the physical characteristics of being insoluble in both water and organic solvents. For this type of pesticide, improving the dosage form and enhancing the performance of the formulation are both very difficult.

[0008] The existing process for synthesizing the technical substance and preparing the dosage form of zinc thiazole is as follows: (1) Technical substance synthesis. First, a 2-amino-5-mercapto-1,3,4-thiadiazole precursor is synthesized, and then reacted with a zinc salt to form a zinc thiazole precipitate. After separation, washing, and drying, a solid zinc thiazole technical substance is obtained. (2) Formulation processing. Using the solid technical substance of zinc thiazole as the raw material, crushing, grinding, mixing, and other processes are carried out to obtain a zinc thiazole suspension. The above technical substance synthesis and formulation processing process requires corresponding production workshops and equipment, such as filters, dryers, crushers, grinders, and mixers. The entire process is both lengthy and energy-consuming.

[0009] Prior Art 1: Chinese invention patent CN114073250A, "A Suspension Concentrate Containing Nano-Zinc Thiazole and Its Preparation Method," discloses a technology for preparing a nano-scale zinc thiazole suspension concentrate. However, this technology uses a traditional suspension concentrate preparation process, where the zinc thiazole technical and one or more of a surfactant, thickener, preservative, defoamer, and antifreeze agent are combined with water and subjected to a cyclic or multi-stage sanding process to produce the nano-suspension concentrate.

[0010] The obvious shortcomings of this technology are:

[0011] ① The current state of the art tells us that it is difficult to process pesticide technicals into nano-sized particles using traditional mechanical equipment and mechanical force. In particular, using traditional production equipment and processes, it is essentially impossible to produce suspension concentrates with particle sizes all below 100 nanometers. The data in the patent specification also confirms this. This is one of the obvious technical shortcomings of this technology.

[0012] ② The "surfactants" used in this technology are all anionic surfactants. Considering the type of surfactant, anionic surfactants are usually monovalent metal salts or their ammonium salts. When anionic surfactants in an aqueous solution encounter polyvalent metal ions, such as zinc ions, they will be replaced by the polyvalent metal ions, thereby losing water solubility and precipitating in the water. If cationic and zwitterionic surfactants are used, during the reaction between thiadiazole salts and zinc sulfate, their basic groups can react with the acidic groups of thiadiazole, disrupting the formation of thiadiazole zinc. Therefore, from the technical perspective of preparing thiadiazole zinc suspensions less than 100 nanometers, the use of anionic surfactants should be avoided. This is another obvious technical defect of this technology.

[0013] Prior Art 2: Chinese invention patent CN107047573A, "Method for Preparing Nano-thiazole Zinc," discloses a method for first producing nano-thiazole zinc technical and then producing thiazole zinc single-dose or compounded formulations. This method for producing nano-thiazole zinc technical involves dissolving a zinc salt and an adjuvant in water, adding a thiadiazole salt solution, and uniformly stirring until a suspension forms. Alternatively, the adjuvant is added to a thiadiazole salt solution, followed by an aqueous zinc salt solution, uniformly stirring until a suspension forms, and finally separating and drying to obtain powdered thiazole zinc. This method for producing nano-thiazole zinc compounded compositions involves combining the aforementioned powdered thiazole zinc with agriculturally acceptable excipients and a fungicide to obtain a wettable powder, water-dispersible granules, suspension, or granules.

[0014] The obvious shortcomings of this technology are:

[0015] ① The technical production process still follows the traditional reaction process and production model. The resulting reaction product is a suspension, which is then dried to obtain a powdered zinc thiazole. Common physics tells us that a liquid product with a "suspension" appearance indicates that its particles are already in the submicron and micron range, as only particles that appear as a transparent liquid are smaller than 100 nanometers. Furthermore, the subsequent drying process inevitably leads to particle aggregation and crystal growth. Therefore, the powdered technical described in this technology cannot fully achieve nanometer dimensions. This is common knowledge in nanofabrication technology.

[0016] ② Using this original drug as raw material and the traditional preparation production process, whether it is a single dose of thiazole zinc or a compound preparation, the particle size of the preparation cannot achieve a true nano size, and is far from achieving a level below 100 nanometers.

[0017] [Summary of the invention]

[0018] One of the objectives of the present invention is to overcome the shortcomings of the existing technology and provide a novel approach and method for preparing traditional zinc thiazole technical and suspension concentrates, which differ from existing technologies. The present invention proposes a dilution process to react a pesticide precursor with a zinc salt in an aqueous solution to produce zinc thiazole. The resulting zinc thiazole nanoparticle suspension dispersion is water-soluble and transparent.

[0019] Another object of the present invention is to compound zinc thiazole with kasugamycin, a fungicide with excellent control effects against fungal diseases, in order to improve the control effect of zinc thiazole and expand its fungicidal spectrum, so as to have a synergistic effect and reduce the dosage of a single variety. When a zinc thiazole nanosuspension dispersion is obtained, a diluted kasugamycin aqueous solution is also obtained, i.e., a zinc thiazole / kasugamycin nanosuspension dispersion is obtained simultaneously.

[0020] The zinc thiazole / kasugamycin nano-suspension dispersion of the present invention can be directly sprayed after being loaded into a pesticide spraying device.

[0021] The innovative ideas of the present invention are as follows:

[0022] The precursor of zinc thiazole is 2-amino-5-mercapto-1,3,4-thiadiazole (abbreviated as thiadiazole). To maintain its stability, it can be salified with a monovalent metal or ammonia to form its sodium, potassium, or ammonium salts. These salts are highly water-soluble and exist as a single molecular dispersion in water, serving as one component. The zinc salt that reacts with it is also soluble in water and is also dispersed as molecules and metal ions in water, serving as another component. When the two meet under stirring, a substitution reaction between the ions occurs rapidly, easily forming zinc thiazole. By controlling the reaction conditions, the amount of zinc thiazole produced, as well as its nucleation and crystallization growth processes, a nano-suspension dispersion of zinc thiazole can be obtained.

[0023] Kasugamycin, whose chemical name is (5-amino-2-methyl-6-(2,3,4,5,6-pentahydroxycyclohexyloxy)tetrahydropyran-3-yl)amino-α-iminoacetic acid, has a molecular formula of C 14 H 25 N3O9. Kasugamycin is an agricultural antibiotic fungicide. Its characteristics: It has strong systemic properties, allowing it to be rapidly absorbed by plants and transported throughout the body, exerting its bactericidal effects. It has excellent control effects on a variety of bacterial and fungal diseases, especially rice blast. Kasugamycin acts on the amino acid metabolic esterase system of pathogens, disrupting protein biosynthesis and normal function of this system. This inhibits mycelial growth and causes cell granulation, rendering the pathogen incapable of reproduction and infection, thereby achieving the goal of disease control. Through the synergistic effects of these multiple mechanisms, it interferes with the normal physiological metabolism of pathogens, effectively inhibiting their growth and reproduction, thus achieving disease control. Pure kasugamycin appears as white crystals, while the hydrochloride salt appears as white needle-shaped or flaky crystals. The pure product is poorly soluble in organic solvents, dissolving 12.5% ​​(w / v) in water at 25°C. The hydrochloride salt is readily soluble in water but insoluble in organic solvents such as methanol, ethanol, acetone, and benzene. It is relatively stable under acidic and neutral conditions. It is easily destroyed and ineffective when encountering alkaline solution.

[0024] Kasugamycin has a broad spectrum of activity and is effective against a wide range of bacterial diseases, including bacterial wilt, soft rot, bacterial angular leaf spot, gummosis, rice blast, scab, leaf spot, and canker, among over 30 others. It also has some control effects against some fungal diseases, such as early blight, anthracnose, and gray mold. It has strong systemic penetration: After application, it is rapidly absorbed by the plant and penetrates through the foliage to the underside, dispersing throughout the plant to rapidly kill pathogens. It is highly safe, with very low toxicity and low environmental residues, meeting modern environmental standards and making it suitable for the production of green and organic agricultural products. It also has a long-lasting effect: It resists rainwater erosion, adheres well to the plant after application, is not easily washed away by rain, and maintains its sustained fungicidal effect. It also has excellent compatibility with various fungicides, achieving significant synergistic effects. It also has a certain regulatory effect on crop growth. While preventing and controlling a variety of diseases, it can also stimulate crop growth, induce plant resistance responses, and enhance plant immunity.

[0025] The main drawbacks of kasugamycin include: Relatively weak killing ability. Its direct killing ability against pathogens is not very strong, but rather acts as an inhibitor. Weak protective properties: While effective as a therapeutic fungicide, its protective effect is relatively weak when used as a protective agent before a disease occurs. Some crops, such as beans, are sensitive to kasugamycin. Combining zinc thiazole with kasugamycin, which is prone to developing resistance, has the following performance improvements:

[0026] Broader bactericidal spectrum. Thiazole zinc has outstanding preventive effects mainly on bacterial diseases and also has a certain inhibitory effect on some fungal diseases. Kasugamycin is effective against a variety of bacteria and some fungal diseases. When combined, the two can simultaneously prevent and control more types of pathogens, covering more types of crop diseases, such as bacterial leaf streak and rice blast on rice. For some mixed bacterial and fungal diseases, a single agent is often difficult to fully prevent and control, while a compound agent can solve multiple disease problems at one time, reducing the number of applications and costs.

[0027] Enhanced bactericidal effect. Thiazole zinc and kasugamycin have different bactericidal mechanisms. Thiazole zinc kills bacteria mainly by destroying the cell membrane of pathogens and interfering with the metabolism of pathogens; kasugamycin interferes with the physiological metabolic process of pathogens. After compounding, the two work synergistically to attack pathogens from different angles, making it difficult for pathogens to develop drug resistance, thereby improving the bactericidal effect. For some highly resistant pathogens, a single agent may not be effective, while compound agents can more effectively control the disease. For example, when preventing and treating citrus canker, the combination of thiazole zinc and kasugamycin still has a good control effect on pathogens that have already developed resistance.

[0028] Improve crop safety. Appropriate compounding can reduce the concentration of individual pesticides, thereby minimizing the risk of crop damage. Combining zinc thiazole and kasugamycin in appropriate proportions ensures effective control while minimizing adverse effects on crops. Compounding pesticides may also reduce negative environmental impacts. Lower concentrations mean less pesticide residue in the environment, minimizing impacts on soil, water sources, and ecosystems.

[0029] Promote crop growth. Kasugamycin can stimulate crop growth to a certain extent and improve crop resistance. Thiazole zinc can also supplement crops with zinc, enhancing their photosynthesis and immunity. When the two are combined, the growth-promoting effect on crops is more obvious, helping to increase crop yield and quality. When crops are stressed by diseases, the compound agent can restore the crop's growth state more quickly and reduce losses caused by the disease. For example, after using the thiazole zinc and kasugamycin combination on vegetables, the vegetables grow stronger, the leaves are greener, and the yield and quality are improved.

[0030] The combination of zinc thiazole and kasugamycin can prevent and control the following crop diseases

[0031] Rice: Bacterial leaf streak is a major bacterial disease of rice. Compound pesticides can inhibit the growth and reproduction of the pathogen, reducing the occurrence and spread of the disease. They also have a certain control effect on rice blast, especially leaf blast and panicle blast.

[0032] Vegetables: For cucumbers, it can prevent and treat bacterial angular leaf spot, effectively reducing leaf spots, maintaining normal leaf function, and improving cucumber yield and quality. For tomatoes, it effectively prevents bacterial diseases such as tomato wilt and canker, reducing damage to tomato plants and ensuring normal fruit development. For cabbage, it helps prevent and treat soft rot, reducing rot during growth and increasing its commercial value.

[0033] Fruit trees: Citrus: Primarily used to control citrus canker, it effectively controls the spread of the disease, protects citrus leaves and fruit, and reduces fruit drop and rot. For peaches, it has a limited control effect against bacterial puncture, alleviating leaf puncture and fruit damage, ensuring normal growth and yield. For pears, it can be used to control fire blight, reducing the damage to the tree and protecting its branches and fruit.

[0034] Tobacco and flowers: It can prevent and control bacterial diseases such as tobacco wilt and wildfire, reducing damage to tobacco plants and increasing tobacco leaf yield and quality. It also has a certain preventive effect on some bacterial diseases of flowers, such as rose black spot (some black spot diseases are caused by bacteria), maintaining the ornamental value of flowers.

[0035] The dosage of thiazole zinc and kasugamycin when combined will vary depending on factors such as the specific crop, disease situation, and dosage form of the agent. Generally speaking: the conventional dosage of thiazole zinc in compound agents is generally around 10 to 50 grams per mu, but the specific use may be adjusted according to the actual situation. In some early stages of the disease or when the disease is relatively mild, the dosage can be appropriately reduced. The dosage of kasugamycin is usually around 1.5 to 5 grams per mu. A reported thiazole zinc / kasugamycin combination ratio is 7 / 1, and its dosage form is a traditional suspension concentrate. No other nano-preparations have been found, let alone nano-suspension dispersions.

[0036] The zinc thiazole nanosuspension is prepared by reacting two components using a dilution process. Before the reaction begins, one component (e.g., an ammonium salt, sodium salt, or potassium salt of thiadiazole) is stirred. An aqueous solution of a component (e.g., zinc sulfate) or an aqueous additive solution is then added to the additive solution of the other component under controlled stirring speed. By controlling the addition and stirring speeds, zinc thiazole nanoparticles and their suspension dispersion can be generated. If an aqueous solution of kasugamycin is also present in one component, the resulting zinc thiazole nanosuspension dispersion also contains a monomolecularly dispersed aqueous solution of kasugamycin.

[0037] Formation Mechanism of Thiazole Zinc / Kasugamycin Nanosuspension Dispersion

[0038] In the system, thiadiazole salts and zinc ions meet to form zinc thiazolium molecules, which then aggregate to form zinc thiazolium nanocrystals. When the particles are very small and few in number, they can be temporarily and stably dispersed in the aqueous system. As the nanocrystals continue to form, they collide, grow, and aggregate. When the size of the zinc thiazolium nanocrystals approaches the wavelength of visible light, the system begins to exhibit an opalescent sheen. Beyond this, the system gradually becomes opaque. Combined with the force of gravity, the system precipitates as crystals. To prevent this, a water-soluble polymer additive must be present in the system. When dissolved in water, the water-soluble polymer additive forms a random coil structure. A random coil is a loose, spherical structure formed by the spontaneous coiling of water-soluble polymer chains. The interior is composed of lipophilic and hydrophobic molecular chains, while the exterior is composed of hydrophilic polar groups. Numerous random coils aggregate into micelles. At this point, when the zinc thiazole nanoparticles generated in the system are less than 100nm, especially less than 50nm, they diffuse into the interior of the random coils and micelles under the influence of stirring shear forces. These random coils and micelles isolate and prevent effective collisions between the grains, thereby preventing further growth, aggregation, precipitation, and settling. Therefore, the water-soluble polymer additive disperses, suspends, stabilizes, and protects the zinc thiazole nanoparticles. When the grain size is below 100nm, especially below 50nm, the system becomes clear and transparent, appears water-soluble, and exhibits the "Tyndall phenomenon."

[0039] It should be noted that during the production of zinc thiazole nanoparticles, the addition rate of a component and the stirring speed of the system affect the amount of reactants added per unit time and the uniformity of the product dispersion. These factors influence the concentration of reactants in the microscopic reaction zone and are crucial factors influencing the rate of product formation and the size of the resulting nanoparticles. Regarding the addition rate, the goal is to produce nanoparticles with a size of less than 100 nm, and the clarity and transparency of the system are used as the criterion. The theoretical basis for this is that when the particle size is less than one-quarter of the lower limit of the visible light wavelength (400-760 nm), that is, less than 100 nm, there is no significant refraction or reflection, only slight scattering, and the system is transparent, exhibiting the "light pillar" phenomenon known as the Tyndall effect. Conversely, if the system exhibits opalescence or opacity, it indicates a particle size greater than 100 nm. The "suspension" described in the aforementioned comparative art demonstrates particle sizes above the micrometer level.

[0040] Kasugamycin is added to one component in the form of an aqueous solution. When the two components are mixed, the water-soluble kasugamycin (usually its hydrochloride) does not participate in the reaction to form zinc thiazole and remains dissolved in the diluted aqueous solution. At this point, the zinc thiazole nanoparticle dispersion and the kasugamycin monomolecular dispersion coexist. Due to the dilution of the water, the kasugamycin is more fully dispersed.

[0041] To achieve the above goals, we must pay attention to the following points:

[0042] ① The mixing speed of the two-component solution (i.e., the speed at which one component is added) should not be too fast. If the two components are added too quickly, the two components will be unevenly dispersed, and the local concentration will be too high. This will also accelerate the formation of product crystals, which may cause aggregation between the resulting crystals, resulting in larger grain sizes. If the system exhibits opalescence, it indicates that the grain size is already several hundred nanometers. Therefore, the speed of adding one component should be based on maintaining the system's transparency.

[0043] ② The stirring speed of the system should be appropriately increased. The stirring speed of the system is related to the formation and dispersion rate of the product nanoparticles in the aqueous phase. Adequate stirring and rapid diffusion promote the rapid formation and dispersion of nanoparticles, maintain small particle size, and avoid aggregation of particles. The stirring speed should be coordinated with the addition rate of the components to ensure that the system remains transparent.

[0044] Explanation of terms

[0045] Dispersed system: A dispersed system is formed when one or more substances are dispersed in another. The dispersed substance in a dispersed system is called the dispersed phase, and the other substance is called the dispersion medium. Based on the size of the dispersed phase particles, dispersed systems are categorized as: molecular (ionic) dispersed systems (particle size < 1 nm) and colloidal dispersed systems (particle size < 100 nm).

[0046] Colloids and Sols: A colloid is a state in which matter exists at a certain degree of dispersion, rather than being an inherent state of a particular type of substance. Many normally insoluble substances can, under appropriate conditions, disperse in a medium to form a seemingly uniform solution. While superficially indistinguishable from a true solution, their diffusion rate and permeability, among other factors, place them within the realm of colloidal substances and are referred to as sols.

[0047] Classification of colloidal solutions: Based on their stability and the structure of their colloidal particles, they are divided into the following categories: 1. Lyophobic sols, formed by the dispersion of insoluble substances in a dispersing medium, are referred to as sols. These particles consist of varying numbers of molecules, exhibiting large interphases and apparent free energies. These sols are unstable, easily disrupted and subject to aggregation, and cannot be restored to their original state, making them thermodynamically unstable and irreversible systems. 2. Solutions of polymer compounds, whose molecular size reaches the colloid range and possesses colloidal properties, are true solutions of dispersed molecules, resulting in thermodynamically stable and reversible systems. These sols are also known as lyophilic sols.

[0048] Tyndall effect: When a beam of light passes through a colloid, a bright "pathway" can be observed in the colloid perpendicular to the incident light. This phenomenon, also known as the Tyndall effect, is essentially the scattering of light when propagating through a colloid. This phenomenon occurs primarily because the particle size of colloidal particles ranges from 1 to 100 nm, resulting in a significant scattering effect of visible light passing through the colloid, while true solutions scatter very little light. Colloids exhibit a pronounced Tyndall effect, while true solutions with dispersed molecules exhibit virtually no light scattering. Therefore, it is often used to distinguish colloidal solutions from true solutions.

[0049] If the particles are smaller than the wavelength of the incident light, light scattering occurs, with the light waves radiating outward around the particles, a phenomenon known as scattered light or opalescence. The Tyndall effect is essentially a phenomenon of light scattering, also known as opalescence. True solutions scatter light very weakly. The intensity of scattered light also increases with increasing particle concentration in the dispersed system. Therefore, when the observed solution is clear and transparent, it indicates that the particle size in the solution is less than 100 nm, and the Tyndall effect may occur. If the particles approach or exceed the wavelength of the incident light (400-740 nm), significant light reflection occurs. When the solution displays increasing opalescence, turbidity, or even opacity, the particle size has increased to near micrometers or above.

[0050] System: The term "system" refers to the suspension dispersion system formed by mixing two components under controlled addition rate and stirring during the preparation of the zinc thiazole nanosuspension in the present invention. The system is the target product—a nanosuspension dispersion—formed by mixing water, a precursor solution, a water-soluble polymer additive, and the generated zinc thiazole.

[0051] Component: A component is a composition comprising one or more ingredients. In principle, any ingredient used in this invention can constitute a component on its own. However, for ease of packaging, transportation, and use, the components should be simplified. The principles are: 1) the ingredients should not react with each other; 2) the number of components should not be too large.

[0052] Ingredients: The so-called ingredients refer to the raw materials used in the present invention, including ammonium salt (or sodium salt, potassium salt) of thiadiazole, zinc salt, water-soluble polymer auxiliary agent, kasugamycin and water.

[0053] Precursor: The so-called precursor refers to the parent substance used to generate the target product zinc thiazole, namely 2-amino-5-mercapto-1,3,4-thiadiazole ammonium salt (or sodium salt, potassium salt).

[0054] Water-soluble polymer additives are water-soluble polymers containing hydrophilic polar groups within their macromolecules. They are also known as polymer surfactants or polymer additives. Water-soluble polymer additives can provide dispersion, suspension, emulsification, and stabilization. Based on the nature of the groups, they can be categorized as anionic, cationic, zwitterionic, and nonionic polymer additives.

[0055] Particle size: also known as particle size; refers to the size of the thiazole zinc crystals formed by the interaction of the precursor with the zinc salt under the dispersion of the water-soluble polymer additive in the system, and does not specifically refer to the microscopic morphology of the crystals.

[0056] Sub-100 nanometers: This is a statistical classification of the pesticide particle size in a system. Pesticide particle sizes in a suspension exhibit a statistical distribution. The sub-100 nanometer nanosuspension described herein means that at least 90% of the pesticide particles are smaller than 100 nanometers. Thus, particles larger than 100 nanometers constitute only a small fraction.

[0057] Effective stirring speed: The so-called effective stirring speed refers to the ability, under a specific addition method, to disperse the nanocrystals generated in the system promptly when one component is added to another, by stirring at a speed no less than the effective stirring speed, preventing grain growth and aggregation, and preventing the grain size from increasing to several hundred nanometers. Transparency of the resulting liquid in the system is a sign of achieving an effective stirring speed.

[0058] Effective stirring: The addition of components and the stirring method and speed have a significant impact on the resulting liquid. Stirring methods include mechanical stirring, multi-point mechanical stirring, manual stirring, and multi-point manual stirring. Fast stirring speeds are associated with optimal results. If the resulting liquid is transparent, the stirring is considered effective. Otherwise, the stirring is considered ineffective.

[0059] Pre-stirring: When one component (the additive) is added to another (the matrix), the relative speed at which the two components contact each other affects whether the nanocrystals generated in the system can be dispersed in a timely manner. Pre-stirring the matrix component before adding the additive, i.e., stirring the matrix component in advance so that the matrix component rotates at a certain speed, can achieve a good dispersion effect. Generally, the pre-stirring speed should reach or be close to the effective stirring speed.

[0060] Addition method: The so-called addition method includes the order in which the different components are mixed with water to form two components. The two components can be added one after the other, or vice versa. Addition methods include continuous addition, intermittent addition, trickle addition, dropwise addition, spray addition, and addition at a fixed or mobile position. The addition method is preferably to achieve rapid mixing and dispersion.

[0061] Addition speed: After determining the addition method, control the amount of components added with the goal of achieving effective stirring.

[0062] The zinc thiazole / kasugamycin nano-suspension dispersion of the present invention refers to a zinc thiazole / kasugamycin nano-suspension dispersion of less than 100 nm; the zinc thiazole / kasugamycin nano-suspension dispersion of less than 100 nm is formed by diluting and mixing two components with water:

[0063] Component A: a water-soluble thiadiazole salt aqueous solution, comprising a water-soluble polymer auxiliary agent and a kasugamycin aqueous solution; the water-soluble thiadiazole salt is one of ammonium thiadiazole, sodium thiadiazole, potassium thiadiazole, or a mixture of at least two of the three.

[0064] Component B: zinc salt or aqueous solution of zinc salt.

[0065] The component B may be further added with a water-soluble polymer auxiliary agent to form an aqueous solution.

[0066] The water-soluble polymer auxiliary agent is a nonionic surfactant.

[0067] The ratio of the amount of the water-soluble polymer additive to the amount of water used for dilution is at least within 1:1000, preferably within 1:800.

[0068] The nonionic surfactant may be (at least one) water-soluble starch and its derivatives, water-soluble cellulose and its derivatives, water-soluble guar gum and its derivatives, water-soluble chitosan and its derivatives, polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymer, aliphatic polyoxyethylene ether, aliphatic aromatic polyoxyethylene ether, aliphatic phenolic polyoxyethylene ether, aliphatic aromatic polyoxypropylene polyoxyethylene ether, castor oil polyoxyethylene ether, alkyl polyglycoside, etc.

[0069] Preferred are polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymers, aliphatic polyoxyethylene ethers, aliphatic aryl polyoxyethylene ethers, aliphatic phenolic polyoxyethylene ethers, aliphatic aryl polyoxypropylene polyoxyethylene ethers, castor oil polyoxyethylene ethers, alkyl polyglycosides, and the like.

[0070] The zinc salt is selected from at least one of zinc sulfate, zinc acetate, zinc chloride and zinc nitrate.

[0071] Furthermore, the zinc thiazole nanosuspension with a size below 100 nm has a stability period of hours.

[0072] For thiadiazole salts and zinc salts, when they are thiadiazole ammonium and zinc sulfate respectively, the range of their mass ratio is:

[0073] Thiadiazole ammonium (the mass of thiazolidine zinc is 100): zinc sulfate = 90: 45-55

[0074] Preferably, thiadiazole ammonium: zinc sulfate = 90: 47-53

[0075] Furthermore, thiadiazole ammonium: zinc sulfate = 90: 48-50

[0076] When the mass ratio of thiadiazole ammonium (the mass of the generated thiadiazole zinc is 100): zinc sulfate = 90:48-50, the mass of the water-soluble polymer additive added to component B, which dissolves the zinc salt in as little water as possible, is preferably such that no turbidity occurs, and is usually not more than 10%.

[0077] In order to achieve better preparation results, the two components should be pre-stirred before mixing. That is to say:

[0078] The zinc thiazole / kasugamycin suspension dispersion of the present invention having a size of less than 100 nm is prepared by diluting two components with water and mixing them under pre-stirring conditions.

[0079] Thiazole zinc / kasugamycin suspension dispersion below 100nm

[0080] In order to improve the efficacy of the nano-scale zinc thiazole / kasugamycin suspension dispersion, the present invention needs to reduce the particle size of zinc thiazole as much as possible. The original intention of studying nanopesticides is to improve the efficacy of pesticides and reduce the amount of pesticides used. The particle size of traditional pesticide preparations is usually several microns or above. Reducing it to a corresponding few nanometers spans three orders of magnitude. When the size is reduced to different orders of magnitude, the number of increased particles is also different. For example, if the usual particle size of the traditional preparation is reduced from 2μm to 200nm, 20nm, and 2nm, respectively, theoretically, the number of particles will increase by 1000 (10 3 ), 1 million (10 6 ), 1 billion (10 9) times. Therefore, it can be seen that different reductions in particle size and increases in particle number lead to different effects on drug efficacy. Therefore, in order to improve drug efficacy, the particle size should be reduced as much as possible.

[0081] To further enhance the efficacy of the nanoscale zinc thiazole / kasugamycin suspension dispersion, the present invention aims to reduce its particle size to below 100 nm. This is based on two factors. First, the 1-100 nm scale defines the size that nanomaterials and nanoproducts must possess in any one dimension. Second, pesticide particles in the 1-100 nm range are colloidal solutions, appearing water-soluble and transparent. When a beam of light is shone on the dispersion, the boundaries of the light column can be seen, consistent with the description of the Tyndall phenomenon. The less pronounced the light column, the smaller the particle size of the dispersion.

[0082] Concentration of suspension

[0083] In suspensions with low active ingredient concentrations, the number of particles below 100 nm is relatively high, which has little effect on transparency. This is the case when the zinc thiazole dosage is 10 g / mu (1 mu = 1 / 15 hectare, the same below) and the system is diluted with more than 5 kg of water.

[0084] Suspensions with high active ingredient concentrations have fewer particles smaller than 100nm, significantly impacting transparency. Similarly, for a system with 100g / mu of zinc thiazole diluted with 20kg of water, while the suspension may briefly become transparent, the high active ingredient concentration makes the particles more likely to collide with each other, leading to crystal growth and aggregation, significantly affecting the suspension's transparency and stability.

[0085] The dosage of active ingredient, water and adjuvant, the adaptation and balance among them, and the control of the water dilution process are important factors affecting the acquisition of transparent zinc thiazole / kasugamycin suspension dispersion.

[0086] Stable period

[0087] The zinc thiazole / kasugamycin nano-suspension dispersion prepared by the present invention is a type of dispersion that is transparent in appearance and appears water-soluble, but is not a thermodynamically stable system as a whole. Therefore, the time for the suspension to remain transparent in appearance is not infinite, but rather there is a stable period. Considering the operational characteristics of the spraying operation, after the zinc thiazole / kasugamycin nano-suspension dispersion is prepared, the required operating time should be at least more than 1 hour, so the length of the stable period can be described in hours. Therefore, the present invention proposes the concept of a "stable period" for nano-scale zinc thiazole / kasugamycin nano-suspension dispersions below 100 nm. That is, the zinc thiazole / kasugamycin nano-suspension dispersions below 100 nm prepared by the present invention complete the spraying operation within the period when the dispersion remains transparent, and the stable period should reach at least 1 hour.

[0088] From the application perspective, the stable period can be further divided into four time periods: less than 1 hour, 1 to 5 hours, 5 to 10 hours, and more than 10 hours.

[0089] The spraying operation was completed within 1 hour, indicating that the zinc thiazole / kasugamycin nanosuspension dispersion remained transparent, that is, the particle size was ensured to be still less than 100 nm.

[0090] Direct observation can be used to determine changes in the transparency and particle size of the nano-thiazole zinc / kasugamycin nanosuspension. During the stable period, the suspension remains transparent, with particle sizes less than 100 nm. When the suspension becomes unstable, opalescence first appears, indicating that the particle size is beginning to increase. A faint opalescence indicates that the particle size within the suspension is beginning to exceed 100 nm. Gradually increasing opalescence indicates that the particle size has increased to several hundred nanometers. Further turbidity or even opacity indicates that the particle size has increased to the micrometer level or above. Crystallization or precipitation indicates that the particle size has increased to the millimeter level.

[0091] The present invention is applicable to the observation of the stable period of the zinc thiazole / kasugamycin nano-suspension dispersion with a size of less than 100 nm and is applicable to the stable period with different hour levels.

[0092] Hourly stability period

[0093] From the perspective of spraying operations: the stabilization time is about 1 hour, which is not enough for the operation time of spraying operations; if the stabilization period exceeds 10 hours, it is not meaningful to use the spray liquid as a pesticide formulation, because even if the liquid is very stable, it is not conducive to storage and transportation due to the low content of active ingredients and large volume capacity.

[0094] Therefore, the stabilization time is between 1 and 10 hours, and the spraying operations of most pesticide equipment can be completed easily within this time.

[0095] The hour-level stabilization period mentioned in the present invention refers to a stabilization time between 1 and 10 hours.

[0096] For the hourly stable period, further detailed staging can be performed.

[0097] The basic period for spraying operation is 1 to 5 hours; in most cases, the spraying equipment can complete the operation.

[0098] 5 to 10 hours is a sufficient period for spraying operations; it can be used to accommodate spraying operations that are delayed due to special circumstances.

[0099] Components and additives of zinc thiazole / kasugamycin nanosuspension dispersion

[0100] Traditional zinc thiazole single-ingredient and binary compound formulations (suspension concentrates) typically consist of a single component and can be sprayed after dilution with water. However, most pesticide particles are larger than microns in size. To produce a nanoscale zinc thiazole / kasugamycin nanosuspension dispersion, the present invention utilizes at least two components. By diluting the suspension with water according to a specific method, a zinc thiazole / kasugamycin nanosuspension dispersion with a particle size of less than 100 nm can be obtained.

[0101] Taking the three-component model as an example, the following explanation is given.

[0102] Three-component basic scheme

[0103] The basic scheme of the 100nm-scale zinc thiazole / kasugamycin nanosuspension dispersion described in the present invention is a system generated by the mixing reaction of three components. They are:

[0104] Component A: It is composed of ammonium thiadiazole (or sodium thiadiazole or potassium thiadiazole) solid or its aqueous solution, which is the precursor for generating zinc thiadiazole nanoparticles.

[0105] Component A can be ammonium thiadiazole, sodium thiadiazole, potassium thiadiazole, or a mixture thereof. A single component or a mixture of two or more of these components can be used. It can be a solid form, which facilitates packaging, minimizes packaging volume, and dissolves quickly in water before use. However, an aqueous solution can also be used, simply diluting to a desired volume with water before use. Considering the stability of the resulting suspension, a certain amount of water-soluble polymer additive is required. To reduce the number of components, component A typically also contains a certain amount of water-soluble polymer additive.

[0106] Component B: zinc salt solid or its aqueous solution, which is the multivalent metal ion required to generate zinc thiazole nanoparticles.

[0107] Component B, the zinc salt, is selected from at least one of zinc sulfate, zinc acetate, zinc chloride, and zinc nitrate. Component B can be a solid, which reduces packaging volume, or an aqueous solution, which requires a certain volume specification. Component B may also contain a certain amount of a water-soluble polymer additive.

[0108] Component C: Kasugamycin solid or its aqueous solution

[0109] Kasugamycin solid or its aqueous solution is used as component C. As required, a water-soluble polymer auxiliary agent may or may not be added to the kasugamycin aqueous solution of component C.

[0110] The ratio of the total mass of the water-soluble polymer additives in the three components to the amount of dilution water is preferably within 1:800.

[0111] The polymer surfactant selected in the present invention should be carefully considered. Anionic surfactants are typically monovalent metal salts or their ammonium salts. When they encounter polyvalent metal ions in aqueous solutions, they are displaced by the polyvalent metal ions, causing them to lose water solubility and precipitate in the water. This is similar to the turbidity and precipitation that can occur when soap is used in hard water (high in calcium and magnesium ions). Therefore, the present invention selects nonionic surfactants as water-soluble polymer additives to suspend, disperse, and stabilize the zinc thiazole nanoparticles generated in the system.

[0112] The water-soluble polymeric additive described in the present invention is selected from nonionic surfactants. Preferred are triblock copolymers of polyoxyethylene and polyoxypropylene, aliphatic polyoxyethylene ethers, aliphatic aryl polyoxyethylene ethers, vegetable oil polyoxyethylene ethers, and alkyl polyglycosides. It can also be selected from natural products and their derivatives, such as water-soluble starch, water-soluble cellulose, water-soluble chitosan, and water-soluble guar gum nonionic derivatives. The water-soluble polymeric additive described in the present invention is one or more of the above-mentioned nonionic surfactants. For environmental reasons, natural substances and their derivatives are preferred.

[0113] In order to simplify the components and make the packaging, storage, transportation and dilution with water operation simpler, the above three-component system can be combined into two components.

[0114] Two-component improvement plan

[0115] One of the improvements of the present invention is a zinc thiazole / kasugamycin nanosuspension with a size of less than 100 nm and a stability period of hours. It is a system generated by the reaction of two components. They are:

[0116] Component A: A solution consisting of ammonium thiadiazole (or sodium thiadiazole, potassium thiadiazole), a water-soluble polymer additive, kasugamycin, and water. The solution contains a precursor for zinc thiadiazole particles smaller than 100 nm, a water-soluble polymer additive for dispersion, suspension, and stabilization, and water-soluble kasugamycin.

[0117] Here, component A in the two-component solution can be considered equivalent to "component A + component C" in the three-component solution.

[0118] Component B is a zinc salt solid, or an aqueous solution thereof with water, or an aqueous solution thereof with a water-soluble polymer additive and water. The zinc salt is selected from at least one of zinc sulfate, zinc acetate, zinc chloride, and zinc nitrate.

[0119] Since the aqueous solution of zinc salt is affected by the amount of additive added, the amount of water-soluble polymer additive added to component B is limited.

[0120] This improvement plan is to distribute the water-soluble polymer additive used into component A and component B. In view of the fact that the stability of component B will be affected by the amount of water and the amount of water-soluble polymer additive, there is an upper limit to the proportion in component B, unless the limitation of component B to a certain capacity is not considered.

[0121] The present invention takes the example of spraying 1 / 15 hectare (1 mu of land, the same below) with 10 grams of zinc thiazole and 2 grams of kasugamycin (the ratio of the two is about 3 / 1) as the basis for generating (10+2) grams of zinc thiazole / kasugamycin nanosuspension with a size of less than 100 nm, and designs the two components.

[0122] Component A requires approximately 9 grams of thiadiazolamide, sodium thiadiazolamide, or potassium thiadiazolamide, preferably thiadiazolamide, as a precursor, along with 2 grams of kasugamycin, both dissolved in water. Based on the aforementioned principle for distributing additives between components A and B, the vast majority of the water-soluble polymer additive will be distributed in component A. If component A is packaged in a 250-gram mass, the amount of water used is the amount after removing thiadiazolamide, kasugamycin, and the water-soluble polymer additive.

[0123] For component B, first determine the amount of inorganic zinc salt required to react with thiadiazole ammonium. Zinc sulfate is preferred in this invention. It is generally believed that the zinc ion undergoes a displacement reaction with thiadiazole ammonium, but it has a stronger tetravalent coordination ability, coordinating with the sulfur atom on the thiadiazole molecule to form a complex structure.

[0124] In the present invention, when the precursor ammonium thiadiazole is used at a mass of 9 grams (10 grams of zinc thiazolidine produced), the zinc salt is anhydrous zinc sulfate at a mass of 4.8 to 5 grams. If the amount of water-soluble polymer additive in component A is sufficient to suspend and disperse the generated nano-zinc thiazolidine particles, then the water-soluble polymer additive is not required in component B.

[0125] Components A and B must be packaged separately because they react when mixed. If a two-component system is used, component A must be added with an additive, otherwise there will be nowhere to put the additive, unless a separate additive is added as a dedicated third component. This complicates the packaging and dilution process. In addition to the water-soluble polymer additive, component A also contains water-soluble kasugamycin. The condition for adding additives to component A is that thiadiazole ammonium, kasugamycin, and the water-soluble polymer additive are all soluble in water. However, considering the water solubility of thiadiazole ammonium and kasugamycin, as well as the high content of additives, the viscosity of the dispersion is relatively high. For ease of operation, a certain amount of water must be added. After achieving the above-mentioned objectives, the amount of water added should minimize the overall mass of component A to reduce the resulting production, packaging, and transportation costs.

[0126] Component B can be a solid zinc salt, which should be dissolved in water before use. For convenience, aqueous solutions can be used, requiring a certain amount of water. The addition of a water-soluble polymer adjuvant is optional for two reasons: First, a large amount of adjuvant in Component B may form a film on the surface of the zinc salt, adjuvant, and water mixture, hindering the subsequent dilution process. Second, if the amount of adjuvant in Component A is sufficient to suspend and disperse the resulting zinc thiazole nanoparticles, no adjuvant is required in Component B. However, if zinc thiazole is used for disease control in orchards, where the tree canopy is large and the water volume required for spraying is high, water consumption can often reach 200 kg / mu or more. If the amount of adjuvant added to Component A is insufficient to support the dispersion and suspension of the resulting zinc thiazole nanoparticles in such a large dilution solution, an appropriate adjuvant should be added to Component B to compensate for the adjuvant deficiency in the dilution solution. However, the prerequisite is that the amount of additive added to the aqueous solution of zinc salt must ensure that the solution remains transparent and avoid condensation and film formation on the surface of the solution during storage. The mass concentration of the added additive is generally not higher than 10%.

[0127] Although both component A and component B can be increased in mass to address the above difficulties, increasing the dosage of the two components will undoubtedly increase production, packaging, and transportation costs. Taking all these factors into consideration, balancing the dosage of other components and product specifications to minimize the use of other ingredients (adjuvants, water) while maintaining the desired unit mass of zinc thiazole is an important factor to consider.

[0128] Water-soluble polymer additives

[0129] The zinc thiazole / kasugamycin dispersion is a transparent, ready-to-use nanosuspension dispersion of zinc thiazole and kasugamycin obtained by "tank mixing." A water-soluble, dispersing polymeric additive is added to this solution, resulting in a nanometer-sized zinc thiazole suspended in the polymeric additive solution, while kasugamycin is dissolved in water. Because the particle size is less than 100 nanometers, the resulting nanosuspension dispersion of zinc thiazole / kasugamycin is transparent and apparently water-soluble.

[0130] (2) The water-soluble polymer auxiliary agent with dispersing effect is an important component that affects the size of the zinc thiazole nanoparticles generated when the two components are diluted and mixed, as well as whether they can be evenly dispersed and stably suspended.

[0131] (3) Polymeric additives are also called polymeric surfactants. They generally refer to substances with large relative molecular mass and surface activity. Compared with small molecule surfactants, polymeric surfactants not only reduce surface tension but also have other special properties, such as dispersion, suspension, and viscosity increase. Polymeric surfactants can be classified into natural polymers and their derivatives and synthetic polymers according to their source. Polymeric surfactants have a hydrophobic chain structure and hydrophilic groups distributed in the side groups and end groups of the chain, such as hydroxyl, carboxyl, carboxymethyl, sulfonic acid, sulfate, phosphoric acid, amino, etc., and are therefore water-soluble. Water-soluble natural polymers and their derivatives include starch and various derivatives (such as oxidized starch, carboxymethyl starch, modified starch), cellulose and its derivatives (carboxymethyl cellulose, hydroxyethyl hydroxypropyl cellulose), guar gum and its derivatives, chitosan and its derivatives, tea saponin, water-soluble humic acid, sodium lignin sulfonate, derivatives of natural products and polyoxyethylene ethers, etc. Synthetic water-soluble polymers include polyvinyl alcohol, polyvinyl pyrrolidone, sodium polyacrylate, polyacrylamide, polystyrene-maleic anhydride copolymer, and polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymers. Water-soluble synthetic polymers with carbon backbones are not easily biodegradable. For environmental reasons, biodegradable heterochain polymers and their derivatives should be selected to minimize their impact on the ecological environment.

[0132] (4) The reason for selecting polymeric additives in the present invention is to utilize the dispersing and suspending functions of water-soluble polymers in aqueous solutions. A water-soluble polymer with a relative molecular mass of tens of thousands, hundreds of thousands, or even hundreds of thousands typically has a linear polymer chain structure and can be dissolved in water. When a linear polymer is dissolved in water, its aspect ratio is very large, but it does not appear as a straight chain. Instead, due to the flexibility of the molecular chain, it exhibits a curled state, i.e., a "random coil" morphology. The hydrophilic groups in the random coil tend to face the aqueous phase, while the lipophilic hydrocarbon chains curl within the random coil. The size of the random coil depends on the relative molecular mass of the polymeric additive, its concentration, and the polymer chain structure. The larger the molecular weight, the larger the volume of the random coil formed by a single molecule. The more flexible the polymer chain, the easier it is to rotate internally, and the more stretched it is in the solvent, the larger the volume of the random coil. When the concentration of water-soluble polymers is high, random coils formed by different molecules aggregate to form micelles, resulting in a larger volume. Generally, when the molecular weight of a water-soluble polymer is in the tens of thousands or hundreds of thousands, the size of the resulting random coils ranges from a few nanometers to tens of nanometers or larger. If pesticide nanoparticles form in the system, based on the principle that like dissolves like, the lipophilic nanoparticles tend to enter the interior of the lipophilic random coils and become intercalated in different locations within the random coils. When the pesticide nanoparticles are smaller, more nanoparticles can be dispersed within the random coils. Therefore, water-soluble polymer adjuvants can disperse and stabilize the generated nanoparticles. Traditional pesticide suspension concentrates also utilize this principle, but their pesticide particles are micron-sized. Because the micron particles are larger than the random coils and micelles, suspension concentrates are typically opaque. Furthermore, the significant gravity affects their stability. When the size of pesticide particles is reduced by 2 to 3 orders of magnitude, the gravitational effect on the particles is much smaller. Using the same water-soluble polymer surfactant, a more stable suspension and dispersion system can be obtained, making the suspension and dispersion liquid appear water-soluble and transparent in appearance.

[0133] 5. Water-soluble polymer additives are divided into different types according to the properties of the active groups contained in the macromolecular chain, just like small molecule surfactants. They include anionic polymer additives, cationic polymer additives, zwitterionic polymer additives and non-ionic polymer additives. These polymer additives carry active groups of different properties on the side groups or main chains. For example, anionic polymer additives carry acidic groups such as carboxyl groups, sulfonic acid groups, sulfate groups and monovalent metal salts. Such as carboxymethyl starch, carboxymethyl cellulose, lignin sulfonate, humate, sodium polyacrylate, polystyrene-sodium maleate, etc. Cationic polymer additives carry basic groups or salts formed with acidic groups, such as chitosan (hydrochloride), polyacrylamide, and polymers containing pyridine groups on the side groups and being quaternized. Amphoteric polymer additives are polymers that contain both anionic and cationic groups in their molecular structure, such as carboxymethyl chitosan. Non-ionic polymer additives, such as polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymers, and various polyoxyethylene ethers with aliphatic, aliphatic aromatic, aliphatic phenolic, aromatic phenolic, oily, etc. as hydrophobic groups, such as Peregal series, OP series, Tween series, polyol series, ricinoleic acid series, alkyl polyglycosides, etc.

[0134] (6) Among the first three types of polymeric additives, anions, cations, and zwitterions all contain acidic groups, as well as corresponding metal ions and basic groups. The presence of these groups causes the anionic polymeric additives to react with the zinc sulfate metal ions during the reaction between thiadiazole ammonium and zinc sulfate, forming a water-insoluble structure that precipitates. Meanwhile, the basic groups of cationic polymeric additives can react with the acidic groups of thiadiazole, potentially disrupting the formation of zinc thiadiazole. Therefore, generally speaking, anionic, cationic, and zwitterionic polymeric additives are not suitable for use as water-soluble polymeric additives in the present invention.

[0135] (7) The aforementioned water-soluble polymeric additives with dispersing properties are limited to nonionic polymeric additives. The hydrophilic groups of nonionic polymeric additives are mostly random coils formed from polyoxyethylene ethers. These random coils aggregate to form "micelles," with a hydrophilic exterior and a hydrophobic interior. The resulting zinc thiazole nanoparticles enter these micelles, achieving dispersion and stabilization. Furthermore, the nonionic polymeric additives also provide a dispersing and protective effect, dispersing and stabilizing the water-soluble kasugamycin molecules after spraying, preventing crystallization and aggregation.

[0136] (8) The zinc thiazole / kasugamycin nanoparticle suspension is prepared by direct reaction of the precursor ammonium thiazole (or sodium thiazole or potassium thiazole) with a zinc salt during dilution prior to use, thereby forming zinc thiazole nanoparticles. During this process, the water-soluble kasugamycin is not affected and remains dispersed as a single molecule.

[0137] ⑼ Testing has shown that the active ingredient particles in the zinc thiazole / kasugamycin nanosuspension dispersion are approximately 10 to 50 nm in size. This nanosuspension remains stable for 2 to 8 hours without precipitation or settling, and can be directly applied to various pesticide spraying equipment.

[0138] ⑽ In the zinc thiazole / kasugamycin nano-suspension dispersion, the zinc thiazole nanoparticles are directly formed during the dilution process with water before spraying. This solution not only eliminates the synthesis and purification process of preparing zinc thiazole from thiadiazole in the pesticide raw material factory, but also eliminates the multi-step physical processing process of processing the zinc thiazole raw material and kasugamycin into the existing traditional suspension concentrate in the pesticide formulation factory. The solution proposed by the present invention can be directly applied to the plant protection link of agricultural production. The operation process is simple, significantly energy-saving and environmentally friendly, and significantly reduces production costs. The particle size of the zinc thiazole / kasugamycin suspension dispersion obtained is less than 100nm. Because the particle size is thousands of times smaller than that of existing zinc thiazole / kasugamycin suspension concentrates, the nano-suspension of the present invention can significantly improve the efficacy of the drug, achieving a reduction in pesticide dosage and increased efficiency.

[0139] FIG2 is a flow chart of the present invention for preparing the zinc thiazole / kasugamycin nanosuspension dispersion by diluting with water.

[0140] The key technologies of the present invention lie in the following aspects:

[0141] 1. Synthesis of zinc thiazole and formation of zinc thiazole nanosuspension

[0142] This invention innovatively proposes a new model and method for preparing nanosuspensions of water- and organic solvent-insoluble pesticides containing polyvalent metal ions. By utilizing the dilution process required for pesticides, the precursor of the target product is mixed with the corresponding metal salt. By leveraging the rapid reaction of metal ions and controlling the mixing and stirring speeds of the reactants, a directly usable nanosuspension of zinc thiazole with a particle size of less than 100 nm is obtained. This method can also be compounded with kasugamycin to produce a binary composite nanosuspension. This method eliminates both the synthesis and purification steps required by pesticide technical manufacturers to prepare zinc thiazole technical from thiadiazoles, as well as the multi-step processing required by pesticide formulation manufacturers to convert zinc thiazole technical into the traditional zinc thiazole / kasugamycin suspension concentrate. This innovative research approach, preparation model, and method are the most important key technologies of this invention. This key technology is applicable not only to zinc thiazole / kasugamycin, but also to the preparation of nanosuspensions of similar pesticides and their composite pesticides.

[0143] 2. Concentration of zinc thiazole

[0144] The concentration of zinc thiazole in the diluted water can be controlled by controlling the amounts of thiadiazole ammonium in component A and the zinc salt in component B, as well as the amount of dilution water. Specifically, if the dosage of the zinc thiazole active ingredient is fixed (e.g., 10 g / mu), the concentration of zinc thiazole produced by the reaction of thiadiazole ammonium with zinc sulfate is affected by the amount of dilution water. For example, the concentration of thiadiazole ammonium should be controlled within the range of 0.1-0.05 g / kg, and the concentration of zinc sulfate should be controlled within the range of 0.05-0.025 g / kg, corresponding to a water dosage of 10-20 kg. If the amount of water is too low, the resulting particles are large and the transparency of the dilution solution is reduced. This is because the high concentration of particles increases the probability of collisions to form larger particles, which reduces stability and is not conducive to the formation of particles smaller than 100 nm. If the amount of water exceeds 20 kg, while a transparent dilution solution can still be obtained, the concentration of the dispersant in the components is significantly reduced, potentially affecting the stability of the dilution solution. Therefore, controlling the concentration of the final zinc thiazole nanoparticles, that is, controlling the amount of water used for dilution, is another key technology for obtaining a transparent zinc thiazole / kasugamycin nanosuspension dispersion of a certain concentration.

[0145] 3. Type and dosage of dispersant

[0146] Selecting the appropriate type and dosage of dispersant is another key technology for obtaining a zinc thiazole / kasugamycin nanosuspension dispersion. However, when ammonium thiazolamide and a zinc salt are combined in water to form zinc thiazole particles, the dispersion effect of large amounts of water and stirring alone cannot maintain the size of the newly formed zinc thiazole nanoparticles. This is because the nanoparticles dispersed in water are not static; they are constantly undergoing Brownian motion and colliding with each other. These collisions lead to particle fusion, crystal growth, and eventual precipitation. An effective way to prevent the size of the formed particles from increasing is to select the appropriate type and dosage of dispersant to uniformly disperse the active ingredient nanoparticles in the aqueous solution. These dispersants are soluble in water and exist in the form of random coils and micelles. If the resulting zinc thiazole nanoparticles are smaller than 100 nm, for example, a few nanometers or more than ten nanometers, they can enter the interior of the random coils and micelles. These random coils and micelles prevent and mitigate collisions between the particles, thereby improving the stability of the zinc thiazole nanoparticles. This is the important role played by polymer dispersants.

[0147] However, there is a problem here. Water-soluble polymers come in different types. Can all water-soluble polymers be used? The present invention has tested a variety of different types of water-soluble polymers and concluded that they are not. Among the numerous anionic surfactants, cationic surfactants, and nonionic surfactants, only nonionic polymer additives can currently achieve the desired effect, such as fatty polyoxyethylene ethers, fatty aryl polyoxyethylene ethers, fatty phenol polyoxyethylene ethers, fatty aryl polyoxypropylene polyoxyethylene ethers, castor oil polyoxyethylene ethers, OP-10, alkyl polyglycosides, etc., and only a few combinations have the best effect. The reason why anionic surfactants cannot be used is that the reaction mechanism of zinc thiazole formed during the dilution process is essentially a process in which polyvalent metal ions replace ammonium ions or sodium ions to form zinc salts or complexes. When anionic surfactants are used, zinc ions will replace the sodium ions of the water-soluble polymer, making it insoluble in water and precipitating the generated zinc thiazole nanoparticles from the water-soluble state, thus playing a flocculating role. However, the present invention does not exclude the special case where an individual cationic surfactant is optimally combined with an appropriate anionic or nonionic surfactant to dissolve in water without precipitation.

[0148] The important role of the water-soluble polymer auxiliary agent used in the present invention is thus apparent. The present invention utilizes a method of mixing water-soluble thiadiazole ammonium (or sodium thiadiazole, potassium thiadiazole) with a zinc salt, such as zinc sulfate, that provides zinc ions during a dilution process. During the mixing process, the zinc ions and thiadiazole ammonium (or sodium thiadiazole, potassium thiadiazole) react to generate a thiadiazole zinc suspension dispersion of less than 100 nm. In the system, if no surfactant, particularly no nonionic surfactant, is present, the generated nanocrystals will continuously collide with each other, causing crystal growth and aggregation, until macroscopic precipitation occurs.

[0149] The type and amount of the water-soluble polymer adjuvant used in the present invention can be determined through experiments. The type of water-soluble polymer adjuvant can be determined by conducting stability tests on different adjuvants under fixed conditions and observing the effects. The test on the type of adjuvant includes a single dose of a water-soluble polymer adjuvant or a compounded adjuvant of two or more. The present invention will give examples of different types of water-soluble polymer adjuvants in the test examples. The determination of the amount of water-soluble polymer adjuvant will be based on meeting the following two conditions: First, the generated zinc thiazole / kasugamycin nanosuspension dispersion must be transparent in appearance and water-soluble in appearance, so as to ensure that the particle size is below 100nm; second, the stability time of this transparent nanosuspension is between 1 and 10 hours, at least between 1 and 5 hours.

[0150] The amount of water-soluble polymer used in this invention is relative to the amount of water used for dilution. The amount of additive used will increase appropriately as the amount of dilution water used increases. The ratio of additive to dilution water should be at least 1:1000, preferably within 1:800.

[0151] 4. Feeding method

[0152] The method of addition is also a key factor influencing the performance of zinc thiazole / kasugamycin nanosuspensions. Determining the active ingredient content or concentration in the dilution solution effectively determines the water consumption. How is the dilution water distributed? How much is used in Component A and Component B? How is the dilution process performed? These factors all influence the size and stability of the zinc thiazole / kasugamycin particles in the resulting dilution solution. For example, if the water consumption is 100 kg, two issues arise:

[0153] First, how to distribute the amount of water used into the two components to form component A dilution and component B dilution?

[0154] Second, how is it added? Is the component A diluent added to the component B diluent, or vice versa?

[0155] These issues all involve the concentration of reactants at the moment the two components are mixed. Furthermore, the presence or absence of stirring also affects the dispersion of the resulting product. The general principle is that a high concentration of water-soluble polymer in the precursor facilitates the dispersion and stability of the nanoparticles. Stirring, and effective stirring, is recommended. Once the system begins to stir and stabilize, the additive should be added in a manner that promotes uniform dispersion (continuous or intermittent spray addition, dropwise addition, or trickle addition) to facilitate the dispersion and stability of the resulting nanoparticles.

[0156] Preparation method of zinc thiazole / kasugamycin nano-suspension dispersion

[0157] The present invention adopts the following technical solutions:

[0158] The diluted solution of component A is pre-stirred first, and then the diluted solution of component B is added to the diluted solution of component A at a stirring speed not less than the effective stirring speed to form a zinc thiazole / kasugamycin nanosuspension dispersion.

[0159] If the addition is done in the opposite way, that is, adding the diluted solution of component A to the diluted solution of component B, precipitation may occur due to the high concentration of zinc salt.

[0160] The component A diluent and the component B diluent are aqueous solutions formed by diluting the following components A and B with water respectively;

[0161] Component A: a water-soluble thiadiazole salt aqueous solution containing kasugamycin, a water-soluble polymer auxiliary agent, and water; the water-soluble thiadiazole salt is one of ammonium thiadiazole, sodium thiadiazole, potassium thiadiazole, or a mixture of at least two of the three;

[0162] Component B: solid zinc salt or its aqueous solution, which may or may not contain a water-soluble polymer auxiliary agent.

[0163] The addition method, addition speed and stirring speed are controlled so that nano-crystals of zinc thiazole with a size of less than 100 nm are generated in the suspension, that is, a zinc thiazole / kasugamycin nano-suspension dispersion with a size of less than 100 nm.

[0164] Effective stirring speed

[0165] The so-called effective stirring speed refers to the situation where when component B is added to component A, under a certain adding method and adding speed, the nanopesticide crystals generated in the mixed liquid can be dispersed in time through stirring at a speed not less than the effective stirring speed, and no significant crystal aggregation will occur, thus preventing the size of these crystals from increasing to hundreds of nanometers or micrometers, thereby causing precipitation in the system.

[0166] Stirring method

[0167] Mechanical stirring: In the field, such conditions are ideal. Large stirring equipment generally does not exceed 100 rpm, and the specific stirring speed can be adjusted within this stirring rate. However, obtaining large containers with stirring devices in the field is often difficult.

[0168] Manual stirring: This is more suitable for most application scenarios. In this case, the stirring speed must meet the physiological requirements of manual stirring and cannot be too fast.

[0169] For manual stirring, the stirring speed should be consistent with the human body's physiological function. To obtain a stable target product, the material addition rate can be appropriately reduced. The material addition rate can be determined by observing the product's transparent state in the system.

[0170] Joining method and joining speed

[0171] In order to make the added materials more uniform and fine, and to disperse them quickly after entering the system, there are three different ways of adding: stirring first and then adding (pre-stirring), stirring and adding at the same time (synchronous stirring), and adding first and then stirring. The present invention gives priority to the first method of stirring first and then adding. In addition, there can be multiple ways of adding, which can be continuous addition, continuous trickle addition, intermittent addition, or dropwise addition, spray addition. For the dropwise addition method, you can use the manual sprayer commonly available in rural areas to spray addition, and this method of adding has the best effect. The speed of addition is still determined by observing the transparent state of the product in the system to determine how fast the material is added.

[0172] Traditional pesticide formulations sprayed with water as the dispersion medium typically require dilution or mixing of co-used pesticide formulations before spraying, a process commonly known as "tank mixing." The present invention utilizes this process to mix components A and B at specific concentrations, addition methods, and rates in an aqueous solution containing specific polymeric adjuvants, thereby directly producing a transparent, tank-mixed zinc thiazole / kasugamycin nanosuspension dispersion suitable for on-site spraying.

[0173] Dilution water consumption

[0174] Current experimental data indicates that a reasonable starting point is 10 kg or more, depending on the zinc thiazole / kasugamycin concentration. This dilution water usage is strongly correlated with our target stabilization period.

[0175] This is a multivariable problem, and the additives (composition, content) in the components will also affect the stability of the zinc thiazole nanosuspension dispersion.

[0176] The present invention aims to produce a zinc thiazole suspension dispersion with a transparency below 100 nm and a stability period of 1 to 10 hours. When the mass of the precursor and the metal salt (zinc sulfate) reacting with it are fixed, factors that can affect the nanometer size and stability of the particles include the amount of dilution water, the amount of additives used, and the preparation method.

[0177] The amount of water used for dilution can affect the size of the resulting nano-zinc thiazole grains and the duration of their stability. This is because the amount of water used as the dispersion medium affects the concentration of the ammonium thiazolium solution and the zinc sulfate solution at the moment of contact, as well as the uniformity of dispersion. Consequently, this influences the resulting grain size, grain dispersion, aggregation, and growth. The amount of additive used affects its concentration at different water levels, as well as the extent of its dispersion, suspension, and stabilization effects on the resulting nano-particles and the duration of their stability. Too little water will reach a limit. For example, at a dilution water level of 10 kg (assuming a zinc thiazole / kasugamycin dosage of 10 / 2 g / mu), the resulting zinc thiazole concentration is 1 g / L, and the kasugamycin concentration is 0.2 g / L. If the zinc thiazole nanosuspension is unstable, the amount of dilution water will need to be increased.

[0178]

Brief description of the attached drawings

[0179] Figure 1: Flowchart for the preparation of zinc thiazole / kasugamycin nanosuspension dispersion

[0180] [Implementation Method]

[0181] The method of the present invention for preparing a transparent zinc thiazole / kasugamycin nanosuspension dispersion of less than 100 nm in size comprises the following steps:

[0182] In the first step, component A and component B are diluted separately according to different water amounts and different dilution ratios to form component A dilution liquid and component B dilution liquid.

[0183] In the second step, under mechanical stirring (preferably) or manual stirring conditions, the stirring speed is not less than the effective stirring speed, and the component B dilution is evenly added to the component A dilution according to a certain addition method (continuous or intermittent pouring, dropwise addition, spraying, etc.).

[0184] Here are some examples:

[0185] Example 1.

[0186] A zinc thiazole / kasugamycin nanosuspension dispersion can be used to control rice blast and bacterial leaf streak. Conventional suspension concentrates use active ingredients in dosages of 10.5 / 1.5 to 17.5 / 2.5 g / mu. Considering the high efficacy of the nanopesticide, this embodiment uses 10 / 1.5 g / mu. The dilution water volume is 10 kg, resulting in concentrations of 1.0 / 0.15 g / L for the zinc thiazole / kasugamycin nanosuspension dispersion.

[0187] The dosage of each component, the amount of dilution water and its distribution, and the preparation of the solution are listed in the following table:

[0188] How to do it:

[0189] ⑴ In an appropriate container, add water in a distribution ratio of 4 / 5 (8 kg), add component A, stir and dissolve to obtain a transparent diluted aqueous solution of component A.

[0190] ⑵In another container, add water in a distribution ratio of 1 / 5 (2 kg), add component B, stir and dissolve to obtain a transparent diluted aqueous solution of component B.

[0191] ⑶ Under pre-stirring, add the diluted solution of component B to the diluted solution of component A by continuous dropwise addition. Control the addition speed and stirring speed to keep the system transparent until the addition of component B is complete.

[0192] A transparent zinc thiazole / kasugamycin nanosuspension dispersion was obtained, which can be directly used for spraying rice. The stability time of the zinc thiazole / kasugamycin nanosuspension dispersion was observed. The stability time was 4 hours.

[0193] Example 2.

[0194] A zinc thiazole / kasugamycin nanosuspension dispersion can be used to control citrus canker. When diluted with 200 kg of water, the dosage of the active ingredient in conventional zinc thiazole / kasugamycin suspension concentrates is approximately 70 / 10 to 87.5 / 12.5 g / mu. This embodiment uses 70 / 10 g / mu. The resulting zinc thiazole / kasugamycin nanosuspension dispersion has a concentration of 0.35 / 0.05 g / L.

[0195] The dosage of each component, the amount of dilution water and its distribution, and the preparation of the solution are listed in the following table:

[0196] How to do it:

[0197] (1) In an appropriate container, add water in a distribution ratio of 19 / 20 (190 kg), add component A, stir and dissolve to obtain a transparent diluted aqueous solution of component A.

[0198] ⑵ Add component C to the diluted aqueous solution of component A, stir and disperse to obtain a transparent "component A + component C" mixed dilution solution.

[0199] ⑶ In another container, add water in a distribution ratio of 1 / 20 (10 kg), add component B, stir and dissolve to obtain a transparent diluted aqueous solution of component B.

[0200] (4) While pre-stirring, add the diluted solution of component B to the diluted solution of "component A + component C" by continuous spraying. Control the addition speed and stirring speed to keep the system transparent until the addition of component B is complete.

[0201] A transparent zinc thiazole / kasugamycin nanosuspension dispersion was obtained, which can be directly used for spraying citrus fruits. The stability time of the zinc thiazole / kasugamycin nanosuspension dispersion was observed. The stability time was 5.5 hours.

[0202] Example 3.

[0203] A zinc thiazole / kasugamycin nanosuspension dispersion can be used to control tomato bacterial wilt. When the dilution water consumption is 50 kg, the dosage of the active ingredient in a conventional suspension concentrate is 25 / 4 to 35 / 5 g / mu. In this example, the dosage is 25 / 4 g / mu. The resulting zinc thiazole / kasugamycin nanosuspension dispersion has a concentration of 0.5 / 0.08 g / L.

[0204] The dosage of each component, the amount of dilution water and its distribution, and the preparation of the solution are listed in the following table:

[0205] How to do it:

[0206] (4) In a suitable container, add water in a distribution ratio of 9 / 10 (45 kg), add component A, stir and dissolve to obtain a transparent diluted aqueous solution of component A.

[0207] ⑸ In another container, add water in a distribution ratio of 1 / 10 (5 kg), add component B, stir to dissolve, and obtain a transparent diluted aqueous solution of component B.

[0208] (6) While stirring, add the diluted solution of component B to the diluted solution of component A in a continuous dropwise manner. Control the addition speed and stirring speed to keep the system transparent until the addition of component B is complete.

[0209] A transparent zinc thiazole / kasugamycin nanosuspension dispersion was obtained, which can be directly used for spraying tomatoes. The stability time of the zinc thiazole / kasugamycin nanosuspension dispersion was observed. The stability time was 5 hours.

Claims

1. A zinc thiazole / kasugamycin nanosuspension dispersion, characterized in that: The zinc thiazole / kasugamycin nano-suspension dispersion refers to a zinc thiazole / kasugamycin nano-suspension dispersion of less than 100 nanometers; the zinc thiazole / kasugamycin nano-suspension dispersion of less than 100 nanometers is formed by diluting and mixing two components with water: Component A: a water-soluble thiadiazole salt aqueous solution, comprising a water-soluble polymer auxiliary agent and a kasugamycin aqueous solution; the water-soluble thiadiazole salt is one of ammonium thiadiazole, sodium thiadiazole, potassium thiadiazole, or a mixture of at least two of the three; Component B: zinc salt or aqueous solution of zinc salt.

2. The zinc thiazole / kasugamycin nano-suspension dispersion according to claim 1, characterized in that: The zinc thiazole / kasugamycin nano-suspension dispersion with a size below 100 nanometers has a stable period of hours.

3. The zinc thiazole / kasugamycin nano-suspension dispersion according to claim 1, characterized in that: The component B is added with a water-soluble polymer auxiliary agent and water to form an aqueous solution; the water-soluble polymer auxiliary agent is a non-ionic surfactant.

4. The zinc thiazole / kasugamycin nanosuspension dispersion according to claim 1, characterized in that: The ratio of the amount of the water-soluble polymer additive to the amount of dilution water is not greater than 1:1000; Preferably, it is not greater than 1:

800.

5. The zinc thiazole / kasugamycin nano-suspension dispersion according to claim 3, characterized in that: The nonionic surfactant is at least one of the following options: Water-soluble starch and its derivatives, water-soluble cellulose and its derivatives, water-soluble guar gum and its derivatives, water-soluble chitosan and its derivatives, polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymer, aliphatic polyoxyethylene ether, aliphatic aryl polyoxyethylene ether, aliphatic phenol polyoxyethylene ether, aliphatic aryl polyoxypropylene polyoxyethylene ether, castor oil polyoxyethylene ether, alkyl polyglycoside; Preferred are polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymers, aliphatic polyoxyethylene ethers, aliphatic aryl polyoxyethylene ethers, aliphatic phenolic polyoxyethylene ethers, aliphatic aryl polyoxypropylene polyoxyethylene ethers, castor oil polyoxyethylene ethers, and alkyl polyglycosides.

6. The zinc thiazole / kasugamycin nanosuspension dispersion according to any one of claims 1 to 5, characterized in that: The zinc salt is selected from at least one of zinc sulfate, zinc acetate, zinc chloride and zinc nitrate.

7. The zinc thiazole / kasugamycin nano-suspension dispersion according to claim 7, characterized in that: When the thiadiazole salt and zinc salt are ammonium thiadiazole and zinc sulfate, respectively, and the mass of the generated thiadiazole zinc is 100, the range of their mass ratio is: Thiadiazole ammonium: zinc sulfate = 90: 45-55 Preferably, thiadiazole ammonium: zinc sulfate = 90: 47-53 Furthermore, thiadiazole ammonium: zinc sulfate = 90: 48-50.

8. A zinc thiazole / kasugamycin nanosuspension dispersion, characterized in that: The zinc thiazole / kasugamycin nano-suspension dispersion refers to a zinc thiazole / kasugamycin nano-suspension dispersion of less than 100 nanometers; the zinc thiazole / kasugamycin nano-suspension dispersion of less than 100 nanometers is formed by diluting and mixing three components with water: Component A: composed of solid or aqueous solution of ammonium thiadiazole, sodium thiadiazole or potassium thiadiazole; Component B: zinc salt solid or its aqueous solution; Component C: kasugamycin solid or its aqueous solution; component C may further include a water-soluble polymer auxiliary agent.

9. The zinc thiazole / kasugamycin nano-suspension dispersion according to claim 8, characterized in that: The ratio of the amount of the water-soluble surfactant to the amount of dilution water is not greater than 1:

800.

10. The zinc thiazole / kasugamycin nano-suspension dispersion according to claim 8, characterized in that: The zinc thiazole / kasugamycin nano-suspension dispersion with a size below 100 nanometers has a stable period of hours.

11. The zinc thiazole / kasugamycin nanosuspension dispersion according to claim 8, characterized in that: The zinc salt is selected from at least one of zinc sulfate, zinc acetate, zinc chloride and zinc nitrate.

12. The zinc thiazole / kasugamycin nano-suspension dispersion according to claim 8, characterized in that: The water-soluble surfactant is selected from nonionic surfactants.

13. The zinc thiazole / kasugamycin nano-suspension dispersion according to claim 12, characterized in that: The nonionic surfactant is selected from: Triblock copolymers of polyoxyethylene and polyoxypropylene, aliphatic polyoxyethylene ethers, aliphatic aryl polyoxyethylene ethers, aliphatic phenolic polyoxyethylene ethers, aliphatic aryl polyoxypropylene polyoxyethylene ethers, vegetable oil polyoxyethylene ethers, alkyl polysaccharides; and can also be selected from natural products and their derivatives such as water-soluble starch, water-soluble cellulose, and water-soluble guar gum nonionic derivatives.

14. A method for preparing a zinc thiazole / kasugamycin nano-suspension dispersion; the component A dilution is pre-stirred, and then the component B dilution is added to the component A dilution under the condition that the stirring speed is not less than the effective stirring speed to form a zinc thiazole / kasugamycin nano-suspension dispersion; The component A diluent and the component B diluent are aqueous solutions formed by diluting component A and component B with water respectively; Component A: a water-soluble thiadiazole salt or its aqueous solution, containing kasugamycin and a water-soluble polymer auxiliary agent; the water-soluble thiadiazole salt is one of ammonium thiadiazole, sodium thiadiazole, potassium thiadiazole, or a mixture of at least two of the three; Component B: is a zinc salt solid or its aqueous solution, and the aqueous solution may or may not contain a water-soluble polymer auxiliary agent.

15. The preparation method according to claim 14, characterized in that: The method of adding one component to another component is one of the following four methods: continuous addition, intermittent addition, dropwise addition, and spray addition.

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