Copper / zinc nanosuspension dispersion

Abstract

The present invention belongs to the field of nano-pesticide, and particularly relates to the preparation of a pesticide which is insoluble in water and solvent and has a particle size less than 100 nanometers. The nano-suspension dispersion of copper oxychloride / zineb is a nano-suspension dispersion in which copper oxychloride and zineb particles are dispersed in water in the form of random coil structure with a water-soluble polymer dispersant.

Description

Copper Oxide / Zineb Nano-Suspension Dispersion

Technical field

[0001] The invention belongs to the field of nano pesticides, and particularly relates to the preparation of a composite suspension dispersion of inorganic copper and zinc compounds that are insoluble in water and solvents and have a particle size of 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 achieve pesticide reduction 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 at 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 even dispersion on the leaves, more extensive contact with the target, and full and enhanced efficacy.

[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] Copper oxychloride (Dicopper chloride trihydroxide), commonly known as copper oxychloride, also known as basic copper chloride, is a light green powder and an inorganic copper compound that can have various structures. The active ingredient of copper oxychloride is copper oxychloride, and its general chemical structure is:

[0006] CuCl2·3Cu(OH)2

[0007] As an ancient and effective pesticide, copper, like Bordeaux mixture and copper hydroxide, is an important copper preparation. Since the early 20th century, it has been widely used in agricultural disease prevention. Its history is closely tied to the development of copper-based fungicides, which are widely used worldwide due to their broad-spectrum efficacy, high efficacy, and relative safety.

[0008] The compound copper oxychloride has inhibitory and killing effects on a variety of plant pathogens. It primarily controls crop diseases through a contact effect, meaning it must be applied directly to plant surfaces to inhibit the growth and reproduction of pathogens by destroying their cell walls or interfering with their physiological processes. Copper oxychloride is particularly suitable for controlling fungal and bacterial diseases of various crops, such as downy mildew in grapes, scab in apples, and late blight in tomatoes and potatoes. These diseases are common in agricultural production and, if not effectively controlled, can seriously impact crop yield and quality.

[0009] In addition to being used alone, copper oxychloride can be mixed with other pesticides to enhance its effectiveness or broaden its control spectrum. For example, mixing it with fungicides such as mancozeb, triazoles, and prochloraz can enhance control of a range of fungal diseases. However, it's important to note that not all pesticides can be safely mixed with copper oxychloride. Pesticides that react chemically with copper oxychloride or reduce its effectiveness should be avoided.

[0010] In summary, as a copper-based fungicide with a long history, Copper Royal still plays an important role in modern agricultural production. Through rational use and integration with other control measures, it can effectively protect crop health and improve the sustainability of agricultural production.

[0011] [Summary of the invention]

[0012] Purpose of the present invention

[0013] One of the purposes of the present invention is to overcome the shortcomings of the existing technology and provide an innovative approach and technical method for preparing copper oxychloride preparations, which is different from the existing copper oxychloride preparation technology - preparing copper oxychloride nano-suspension dispersions. The preparation of traditional copper oxychloride preparations is to use copper chloride and calcium hydroxide to generate copper oxychloride. Due to the low solubility of calcium hydroxide in water, the solubility of the product copper oxychloride in water is extremely low, with a solubility of 5.06×10 –4 g / L (pH 6.5, 20°C), a copper oxychloride precipitate is obtained. This precipitate is then processed into copper oxychloride formulations, including wettable powders and suspension concentrates. The innovative approach and technical method of this invention involves using copper chloride and a water-soluble base to directly produce a nano-suspension dispersion of copper oxychloride through a solution reaction under controlled reaction conditions.

[0014] Another object of the present invention is to compound copper oxychloride with a highly effective, low-toxic, broad-spectrum carbamate protective organosulfur fungicide, maneb, in order to enhance the control effect of copper oxychloride and expand its bactericidal spectrum, thereby achieving a synergistic effect and reducing the dosage of a single variety. This method provides a copper oxychloride nano-suspension dispersion and a maneb nano-suspension dispersion, i.e., a copper oxychloride / maneb nano-suspension dispersion.

[0015] Another object of the present invention is to reduce the particle size of copper oxychloride and mancozeb. Because copper oxychloride and mancozeb are insoluble in both water and organic solvents, current processing technology relies on mechanical crushing and grinding, resulting in only traditional wettable powders and suspensions. These formulations have particle sizes ranging from a few microns to tens of microns, making it difficult to improve their efficacy. The copper oxychloride / mancozeb nanosuspension dispersion prepared by the present invention has a particle size of less than 100 nm, significantly reducing the particle size and thus significantly improving the efficacy of copper oxychloride / mancozeb combination formulations.

[0016] Another object of the present invention is to shorten the production and formulation process of copper oxychloride and mancozeb. Commercially, copper oxychloride and mancozeb are first prepared in a technical manufacturer and then processed into copper oxychloride and mancozeb compound formulations in a formulation factory. The present invention directly uses synthetic copper oxychloride and mancozeb, utilizes the pesticide dilution process with water, and controls the reaction conditions to obtain a transparent copper oxychloride / mancozeb nanosuspension dispersion. This method integrates the synthesis and formulation processes of copper oxychloride and mancozeb, directly eliminating the synthesis and purification processes of the technical materials, the formulation processing technology, and the corresponding expensive production equipment. No wastewater is generated in the process, which is environmentally friendly and energy-saving, with significant results.

[0017] Another object of the present invention is to provide a copper oxychloride / mancozeb nanosuspension dispersion that can be directly used for spraying. The dispersion is prepared to a suitable spraying concentration for crops based on the amount of dilution water and the amount of product generated, allowing for direct spraying. Because the pesticide particles are less than 100 nm in size, their efficacy can be significantly improved, pesticide usage can be reduced, and this contributes to sustainable agricultural development.

[0018] The innovative idea of ​​the present invention

[0019] The different performance characteristics of copper oxychloride and mancozeb

[0020] Copper Royal has a broad fungicidal range. It is effective against a variety of fungal and bacterial diseases, including canker, bacterial leaf spot, yellow spot, snake eye disease, wilt, scab, sooty mold, anthracnose, and angular leaf spot. It is particularly effective against bacterial diseases and effectively addresses crop diseases caused by bacterial infection. It also offers excellent compatibility and can be mixed with many fungicides and insecticides, expanding its control range and enhancing effectiveness. It is rain-resistant. When sprayed on the crop surface, it forms a copper film that not only prevents pathogens from invading but also exhibits good rain-resistance. Even after rainfall, the agent maintains its effectiveness, minimizing the risk of reduced efficacy due to rain. It is also relatively safe. Among copper preparations, Copper Royal has the lowest phytotoxicity. It is highly safe for crops and, when used correctly, is not likely to cause phytotoxicity. It is suitable for a wide range of crops, including citrus, lychees, grapes, tomatoes, and cucumbers. Growth stimulating effect. When used on crops such as potatoes, peanuts, and sunflowers, it can stimulate growth and increase yields. While preventing and controlling diseases, it can also promote crop growth and development, improving crop yield and quality.

[0021] Mancozeb's performance characteristics: It has a broad fungicidal spectrum and is effective against a variety of fungal diseases, including downy mildew, early blight, late blight, anthracnose, leaf mold, and rust, on crops such as vegetables, wheat, grapes, tobacco, and fruit trees. It effectively combats common fungal diseases on a wide range of crops, reducing their damage. It also offers strong protective properties. As a protective fungicide, it works by forming a protective film on the plant surface, preventing pathogens from invading the plant, thereby preventing disease. When used before or in the early stages of a disease, it effectively protects crops from pathogens and reduces their incidence. It is safe and non-polluting to plants. At normal concentrations, mancozeb has no adverse effects on plant growth and development and does not leave residues in plants, making it environmentally friendly and in line with the development of green agriculture. It is easy to use and has good stability, resisting decomposition under normal storage and use conditions. It also provides zinc supplementation. Mancozeb contains zinc, which can not only prevent and control diseases, but also supplement zinc for crops, helping to improve the nutritional status of crops, promote crop growth and development, and enhance crop resistance.

[0022] Performance advantages of copper oxychloride and mancozeb compound:

[0023] Broadens the fungicide spectrum. Copper oxychloride is primarily effective against bacterial diseases, while mancozeb is effective against a variety of fungal diseases. When combined, the two can simultaneously control both fungal and bacterial diseases, significantly broadening the fungicide spectrum. This can effectively address complex disease outbreaks and reduce losses caused by incomplete control of a single disease.

[0024] Enhanced control effectiveness. When combined, fungicides with different mechanisms of action work synergistically, enhancing the effectiveness against pathogens. This can improve control effectiveness and reduce recurrence rates for difficult-to-control diseases, such as those caused by a combination of stubborn fungal and bacterial diseases.

[0025] Delaying the development of drug resistance. Because the two fungicides work by different mechanisms, it's difficult for pathogens to develop resistance to both simultaneously. Long-term use of a combination fungicide can delay the development of resistance and extend the lifespan of the fungicide.

[0026] Improved stability: Copper oxychloride is easily decomposed under alkaline conditions, and mancozeb is also unstable under strong alkaline conditions. When the two are combined, they can stabilize each other to a certain extent, improving the stability of the agent under different environmental conditions.

[0027] Crops and diseases that can be controlled by combining copper oxychloride and mancozeb

[0028] Fruit trees. Apple: Can be used to control fungal diseases such as apple leaf spot, anthracnose, and ring rot, as well as bacterial diseases such as apple fire blight. Citrus: Effective against fungal diseases such as citrus canker (bacterial), anthracnose, and scab. Pear: Can be used to control fungal diseases such as pear scab and rust, as well as bacterial diseases such as pear fire blight.

[0029] Vegetables. Cucumber: Controls cucumber downy mildew and bacterial angular leaf spot. Tomato: Controls tomato early blight, late blight, and canker. Eggplant: Has a certain control effect on eggplant blight, Verticillium wilt (fungal), and bacterial wilt (bacterial).

[0030] Field crops. Wheat: Controls fungal diseases such as wheat head blight and rust, as well as wheat bacterial leaf streak. Rice: Controls fungal diseases such as rice blast and sheath blight, as well as bacterial diseases such as rice bacterial leaf blight. Corn: Controls fungal diseases such as corn leaf blight and leaf spot, as well as bacterial stalk rot.

[0031] The realization of compounding copper oxychloride and mancozeb, and preparing these two pesticides that are "neither soluble in water nor in organic solvents" into a nanopesticide compound formulation, especially the realization of preparing copper oxychloride and mancozeb into a suspended dispersion with a size of less than 100nm, will face huge technical challenges.

[0032] Generally speaking, the mass ratio of copper oxychloride to the active ingredients of mancozeb may be between 1:2 and 2.5:1.

[0033] 1. Technical Challenges

[0034] The development of nanopesticides aims to address the major problems associated with traditional pesticides: environmental pollution, pesticide accumulation in organisms, and the significant increase in pest and disease resistance. These problems stem from the outdated nature of traditional formulations, resulting in large pesticide particles and low efficacy, leading to high residue levels even with high application rates. Nanotechnology can significantly reduce pesticide particle size, improve formulation performance, and reduce pesticide dosage, addressing these issues and minimizing the impact of pesticide use on the environment and human health.

[0035] Most pesticides are insoluble in water but soluble in organic solvents. For these pesticides, the strategy for reducing particle size is to dissolve them in a solvent or complex solvent to form a monomolecular dispersed solution. This solution is then prepared into nanomicelles, nanocrystals, nanospheres, nanocapsules, nanogels, and various nanocarriers through various methods.

[0036] However, pesticides containing polyvalent metal ions are insoluble in both water and organic solvents, limiting their application in nanoscale manufacturing. Copperoxydibenzoylmethane and Zineb are examples of such pesticides. With current technology, conventional mechanical pulverization and ultrafine grinding processes cannot fully achieve nanoscale size, let alone scales below 100 nm. Therefore, preparing pesticides like copperoxydibenzoylmethane and Zineb, either individually or in combination, into transparent suspensions with particle sizes below 100 nm is a globally challenging problem.

[0037] 2. Innovation of the present invention

[0038] The present invention uses copper chloride and a water-soluble base as reactants to produce copper oxychloride, and mancozeb and a zinc salt as reactants to produce zineb. By determining the molecular ratio of the reactants, the type and amount of a high-molecular surfactant (dispersant), and suitable reaction conditions (such as the method and speed of adding the reactants, stirring speed, temperature, and pH value), and utilizing the process of diluting the pesticides with water, a transparent and stable copper oxychloride / zineb nano-suspension dispersion of a certain concentration is prepared. This nano-dispersion can be directly used in spraying operations for preventing and controlling crop diseases.

[0039] The innovative features of the present invention are as follows:

[0040] (1) Innovative preparation of a copper oxychloride / mancozeb nanosuspension dispersion. The particle size of copper oxychloride and mancozeb differs from the micron-sized size of all conventional copper oxychloride / mancozeb formulations, with particles less than 100 nm, making it a significant innovation. The innovative approach to producing this nanosuspension dispersion is to select two reactants that are both soluble in water and divided into two components. Upon contact, the aqueous solutions of the two components react rapidly, due to an ionic reaction, to instantly produce copper oxychloride and mancozeb. Copper oxychloride and mancozeb have extremely low solubility in water, and as they nucleate and crystallize, they tend to precipitate from the water. The present invention employs two measures to prevent precipitation: first, one or more water-soluble polymeric surfactants of selected types and amounts are pre-added as dispersants to the aqueous dispersion system, forming random coils in the aqueous solution; second, appropriate reaction conditions are selected, including reactant concentrations, appropriate addition method and rate, appropriate stirring speed, and appropriate pH value, to control product formation, nucleation, and crystallization rates. In this way, when the product crystals in the system are very small, they are evenly dispersed into the random coils formed by the polymer dispersant in water under stirring. The hindering effect of the random coil molecular network reduces the chance of the resulting product crystals colliding with each other and continuing to grow, thereby dispersing, suspending, and stabilizing the resulting product nanoparticles. This is the microscopic mechanism for obtaining the copper oxychloride / mancozeb nanosuspension dispersion. If the copper oxychloride nanoparticles are sufficiently small, less than 100 nm, then according to the theory of colloidal solutions, the copper oxychloride / mancozeb nanosuspension dispersion will appear transparent.

[0041] (2) The copper oxychloride / mancozeb nanosuspension dispersion exhibits excellent performance. Its transparent appearance demonstrates that the pesticide particles are generally below 100 nm in size, not only meeting national standards for nano-product size but also exceeding the particle size of all existing copper oxychloride and mancozeb formulations. Once the type of pesticide is determined, the primary factors determining its efficacy are the size of the pesticide particles and the properties of the adjuvant. The small and abundant particle size of the pesticide dilution during spraying ensures sufficient contact with the target, reducing pesticide usage while ensuring effective control. Furthermore, the water-soluble polymeric surfactant used as a dispersant in the present invention can be selected from natural substances and their derivatives, as well as synthetic polymers. For environmental reasons, biodegradable natural polymers and their derivatives are preferred. Therefore, the copper oxychloride / mancozeb nanosuspension dispersion is not only highly effective but also environmentally friendly.

[0042] (3) The innovative preparation method for the copper oxychloride / mancozeb nanosuspension dispersion eliminates the traditional technical synthesis and formulation processes for copper oxychloride and mancozeb, as well as the expensive plant and equipment. By utilizing the pesticide dilution process, the reactants used to prepare copper oxychloride and mancozeb are divided into three or two components, which are then mixed in a specific addition pattern to produce the target product—a copper oxychloride / mancozeb nanosuspension dispersion—in a single step. This process eliminates the production processes and equipment required for the synthesis and purification of copper oxychloride and mancozeb technicals, as well as the processing processes and equipment required for compound formulations (wettable powders and suspension concentrates). This not only reduces synthesis and processing costs, but also simplifies the process, facilitates operation, and is environmentally friendly and energy-efficient.

[0043] (4) The concentration of the Copper Oxychloride / Zineb nano-suspension dispersion can be adjusted based on crop type and disease control needs. Using the Copper Oxychloride / Zineb nano-suspension dispersion, the water volume for dilution and spraying can be determined based on the crop type and growth conditions. The concentration of the active ingredient of Copper Oxychloride / Zineb to be sprayed can then be determined based on the severity of the disease. This allows for precise determination of the dosage of Copper Oxychloride / Zineb, as well as the amount of polymer dispersant used.

[0044] 3. Technical ideas of the present invention

[0045] The reactants for copper oxychloride formation can be copper chloride and an alkali compound. Copper chloride and alkalis (sodium hydroxide, potassium hydroxide, and ammonium hydroxide) are both water-soluble and monomolecularly dispersed in water. When the two meet, ion exchange reactions easily form copper oxychloride molecules. The reactants for maneb can be maneb salts (sodium maneb, potassium maneb, and ammonium maneb) and zinc salts. These are both water-soluble and monomolecularly dispersed in water, and their combination also easily produces maneb molecules. This suggests that copper oxychloride and maneb, both of which contain metal ions, undergo similar formation processes.

[0046] The ingredients mentioned above can be divided into two or three components, ensuring that the components do not react with each other, that packaging is simple, and that they are easy to use. Mancozeb and an alkali compound can be one component, copper chloride and a zinc salt can be another, and the required water-soluble polymer additive can be the third. To simplify processing, the water-soluble polymer additive can be added to the first component, creating a two-component solution.

[0047] Under the condition of controlled stirring speed, add the aqueous solution of one component (such as copper chloride, zinc salt) to the aqueous solution of another component (such as maneb, alkali, water-soluble polymer additive and water). By controlling the addition method and speed, and stirring speed, a copper oxychloride / maneb nano-suspension dispersion can be generated.

[0048] Nanocrystals of copper oxychloride and mancozeb, or mixed nanocrystals, are generated simultaneously in the system. When the crystals are very small and few in number, they can temporarily maintain a relatively stable dispersion in the water system. As the nanocrystals continue to form, they collide, aggregate, and grow. When the crystals of copper oxychloride and mancozeb are less than 100 nm in size, the system is clear and transparent. When they are larger than 100 nm and approach the wavelength of visible light, the system begins to exhibit an opalescent sheen and gradually becomes opaque. Combined with the effect of gravity, large crystals precipitate out. To prevent this, a water-soluble polymer dispersant must be added to the system. Water-soluble polymer dispersants are typically linear macromolecules that exist as random coils upon dissolution in water. Random coils are loose, spherical structures 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. At the beginning of the system's formation, the copper oxychloride and mancozeb nanoparticles, under the shear force of mechanical stirring, diffuse into the interior of the random coils and become loaded. This isolates and prevents the subsequent particles from effectively colliding with each other, growing, separating, and settling. Therefore, the random coils formed by the water-soluble polymer dispersant disperse, suspend, stabilize, and protect the copper oxychloride and mancozeb nanoparticles. These random coils are evenly dispersed in the aqueous phase, and the nanoparticles that diffuse into the random coils are also evenly dispersed in the aqueous phase. When the particle size is below 100 nanometers, the system appears clear and transparent, and appears water-soluble.

[0049] It should be noted that during the nanoparticle formation process, the addition rate of the components, the stirring rate, and the diffusion rate of the reactants and products, which affect the instantaneous concentration of the reactants and the dispersion of the products in the reaction zone, are important factors affecting the size of the nanoparticles. Regarding the addition rate, if the target nanoparticle size is less than 100 nm, the clarity and transparency of the system is the key criterion. This is based on the theory that when the particle size is less than one-quarter of the lower limit of the visible light wavelength (400-760 nm), no significant refraction or reflection occurs, and the system is therefore transparent. Conversely, if the system is opalescent or opaque, it indicates that the particle size is greater than 100 nm.

[0050] To achieve this goal, the following points must be focused on:

[0051] (1) Controlling the reaction to generate copper oxychloride and mancozeb nuclei, the speed and number of grains formed, and the rate of crystal growth is the key to obtaining particles smaller than 100nm. This involves factors such as the concentration of reactants in the reaction area, the diffusion rate, the type and amount of water-soluble polymer dispersant, the amount of water used for dilution, and the pH value.

[0052] (2) The strength and selection of alkaline compounds. The formation of copper oxychloride is a reaction between salt and base. The base used in traditional copper oxychloride preparation is slaked lime, that is, calcium hydroxide. Although its alkalinity is relatively weak, its water solubility is poor and its particles are large, making it difficult to separate and control the even less water-soluble copper oxychloride produced in the system, and ultimately forming a larger sized particle precipitate. In addition to calcium hydroxide, other alkaline compounds that can be used are sodium hydroxide, potassium hydroxide, and ammonium hydroxide. The first two are strong bases, and their reaction rates with copper chloride are fast and difficult to control. Ammonium hydroxide has relatively weak alkalinity and its reaction rate with copper chloride is lower than that of the first two, so the rate of copper oxychloride formation is relatively slow. Considering the control of the rate of copper oxychloride formation and the nucleation and crystallization growth of the particles, ammonium hydroxide is preferred as the alkaline compound.

[0053] (3) Selection of the type and dosage of water-soluble polymer additives. Copper chloride reacts with alkali to form copper oxychloride, and mancozeb reacts with zinc salts to form zineb. Since both products are insoluble in water, molecular aggregation will inevitably occur in water, forming crystal nuclei. These nuclei will continue to grow and eventually precipitate from the water. The purpose of the present invention is to control the crystal size of the resulting copper oxychloride and zineb to no larger than 100 nm. To prevent the growth of the crystal nuclei formed in water and to ensure their suspension, dispersion, and stability, a water-soluble polymer dispersant must be added to the system. Water-soluble polymer dispersants have hydrophilic groups, allowing them to dissolve in water to form colloidal solutions. The viscosity of colloidal solutions is much greater than that of small molecule surfactants at the same concentration. The high viscosity of water-soluble polymer solutions is due to the different morphological structures of water-soluble polymers in water compared to small molecules. Due to their large molecular weight and long molecular chains, water-soluble polymers do not form straight chains when dissolved in water, but rather random coils. These random coils are molecularly dissolved and dispersed in water, with sizes ranging from a few nanometers to tens of nanometers, or even hundreds of nanometers or larger, depending primarily on their molecular weight. These random coils suspend nanocrystals generated in the solution. This is due to the loose spatial structure of the random coils, which, under stirring, attract the copper oxychloride and mancozeb crystals generated by the reaction. These coils suspend, disperse, stabilize, and prevent the crystals from agglomerating, thereby preventing and controlling their further growth.

[0054] Water-soluble polymers are classified by type into anionic, cationic, zwitterionic, and nonionic types. They are categorized by source into natural polymers and their derivatives, as well as synthetic polymers. The selection and dosage of water-soluble polymer dispersants are determined through experimentation.

[0055] (4) 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, the local concentration of the reactant will be too high, and the speed of grain formation will also be accelerated. Nanocrystal aggregation may occur, causing the grain size to increase rapidly. If the system develops opalescence, it means that the grain size has exceeded 100nm. Therefore, the speed of adding one component should be based on maintaining the system's transparency.

[0056] 5. 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 nanoparticles in the aqueous phase. Adequate stirring and rapid diffusion help disperse the reactant concentration in the reaction zone, slowing the reaction rate, allowing the rapidly formed nanoparticles to disperse, maintaining small grain size, and preventing aggregation and rapid growth of the grains. The stirring speed should be coordinated with the rate of component addition and should also be based on maintaining the system's transparency.

[0057] Explanation of terms

[0058] 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).

[0059] 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.

[0060] 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 insoluble substances dispersed in a dispersion medium, are referred to as sols. These particles consist of varying numbers of molecules, exhibiting large interphases and apparent free energies. These sols are highly unstable and easily disrupted, leading to aggregation and irreversible return to their original state. 2. Solutions of polymer compounds, whose molecular size reaches the colloid range and exhibits colloidal properties, are true molecular solutions, thermodynamically stable, and reversible systems. These sols are also known as lyophilic sols.

[0061] Tyndall effect: When a beam of light passes through a colloid, a bright "pathway" can be observed 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 significant scattering of visible light when passing through a colloid, while true solutions exhibit very little scattering of light. Therefore, colloids exhibit a pronounced Tyndall effect, while true solutions with dispersed molecules exhibit almost no scattering. Consequently, the Tyndall effect is often used to distinguish colloidal solutions from true solutions.

[0062] A further explanation of the Tyndall effect is that when propagating light strikes particles in a solution, if the particles are larger than the wavelength of the incident light (400nm to 740nm) or many times larger, significant light reflection occurs. If the particles are smaller than the wavelength of the incident light, light scattering occurs, with the observed light waves radiating outward around the particles. This radiated light is called scattered light or opalescence. The Tyndall effect is essentially a phenomenon of light scattering, or opalescence. Since the particle radius of a true solution generally does not exceed 1nm, colloidal particles lie between solute particles and turbidity particles in a solution, with a particle size of 1 to 100nm. This is less than one-quarter the lower limit of the visible light wavelength. Therefore, visible light will be significantly scattered when passing through a colloid. However, since the molecules or ions in a true solution are even smaller, the intensity of the scattered light decreases significantly as the volume of the scattering particles decreases. Therefore, the scattering effect of true solutions on light is very weak. Furthermore, the intensity of scattered light increases with increasing particle concentration in the dispersed system. From this we can judge: when the observed solution is clear and transparent, it indicates that the particle size in the solution is less than 100nm, and the Tyndall phenomenon may occur; when the observed solution shows opalescence or the opalescence becomes increasingly heavier, it indicates that the particle size is greater than 100nm, and the particle size tends to become larger and larger; when the solution is turbid or even opaque, the particle size has increased to microns or above.

[0063] System: The so-called system refers to the system in which, when preparing a transparent copper oxychloride and mancozeb nano-suspension dispersion, an alkali reacts with copper chloride to produce copper oxychloride, and mancozeb reacts with a zinc salt to produce mancozeb, while controlling the addition method, speed, and stirring speed. The system is composed of copper chloride, an alkali compound, mancozeb, a zinc salt, a polymer additive, and water.

[0064] 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, it is advisable to simplify the composition of ingredients. The principles are: 1) the ingredients should not react with each other; 2) the number of components formed by the ingredients should not be too large.

[0065] Ingredients: The so-called ingredients refer to the raw materials used in the present invention, including water-soluble copper chloride, alkali compounds, mancozeb salt, zinc salt, water-soluble polymer additives and water.

[0066] Polymer additives: Also known as polymer surfactants or polymer additives, these are water-soluble polymer compounds containing hydrophilic groups or hydrophobic backbones. Because polymer additives can disperse, suspend, emulsify, and stabilize, they are also referred to as polymer dispersants, polymer suspending agents, and polymer emulsifiers, depending on their primary function. Polymer surfactants can be categorized as nonionic, anionic, cationic, and zwitterionic based on the nature of their groups.

[0067] Water-soluble polymer dispersants, also known as water-soluble polymer additives, refer to polymer compounds that dissolve in water. As surfactants, water-soluble polymers can have many functions. When their primary function is to disperse other substances that are insoluble in water, they are also called water-soluble polymer dispersants.

[0068] Precursor: The so-called precursor refers to the parent substance used to generate the target product. Here, the target products are copper oxychloride and mancozeb, and the precursors are copper chloride and mancozeb respectively.

[0069] Particle size: also known as particle size, refers to the size of copper oxychloride and mancozeb particles generated in the system. These particles are usually crystalline grains and do not specifically refer to the microscopic morphological structure of the grains.

[0070] Sub-100 nanometers: This is a statistical classification of pesticide particle sizes within a system. All particle sizes within the system exhibit a statistical distribution. The sub-100 nanometer dispersion described herein means that at least 80% of the particles are smaller than this size. Particles larger than 100 nanometers constitute only a small fraction.

[0071] Effective stirring speed: The so-called effective stirring speed refers to the ability, under a certain 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 solution is a sign of effective stirring.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] Addition speed: After determining the addition method, control the amount of components added with the goal of achieving effective stirring.

[0076] One of the objectives of the present invention is to overcome the shortcomings of the existing technology and provide a new idea and a new method. By utilizing the process in which pesticide formulations are usually diluted with water when spraying using water as a dispersion medium, the present invention realizes the reaction of copper chloride and alkali to form cuprochloridum, and the reaction of maneb with a zinc salt to form maneb, thereby providing a water-soluble and transparent copperrochloridum / maneb nano-suspension dispersion that can be directly used for spraying.

[0077] The copper oxychloride / mancozeb nano-suspension dispersion described in the present invention can be loaded into pesticide spraying equipment for spraying. It is primarily used to control: apple leaf spot, anthracnose, ring rot, and fire blight; citrus canker (bacterial), anthracnose, and scab; pear scab, rust, and fire blight; cucumber downy mildew and bacterial angular leaf spot; tomato early blight, late blight, and canker; eggplant fusarium wilt, verticillium wilt, and bacterial wilt; wheat scab, rust, and bacterial leaf streak; rice blast, sheath blight, stripe rust, and bacterial leaf blight; and corn large leaf spot, small leaf spot, and stem rot.

[0078] The copper oxychloride / mancozeb nano-suspension dispersion of the present invention refers to a copper oxychloride and mancozeb suspension dispersion of less than 100 nanometers. The copper oxychloride / mancozeb nano-suspension dispersion of less than 100 nanometers is formed by diluting and mixing at least two components with water:

[0079] Component A: an aqueous solution consisting of a precursor maneb, an alkali compound, a water-soluble polymer dispersant and water;

[0080] Component B: Precursor copper chloride, zinc salt solid or copper chloride, zinc salt aqueous solution.

[0081] The component B may be further added with a water-soluble polymer dispersant and water to form an aqueous solution.

[0082] Component A and component B, under the conditions of pre-stirring and effective stirring, generate copper oxychloride and mancozeb particles dispersed in a random coil morphology structure formed by the water-soluble polymer dispersant dissolved in water.

[0083] The water-soluble polymer dispersant is a natural polymer surfactant and its derivative surfactant, or a synthetic polymer surfactant.

[0084] The water-soluble polymer dispersant may be selected from (at least one) water-soluble natural polymers and their derivatives, including starch, cellulose, guar gum, chitosan and their derivatives; aliphatic, aliphatic aromatic, aliphatic phenolic, arylphenolic, oleyl polyoxyethylene ethers; aliphatic polyether sulfates, sulfonates; Tween, alkyl polyglycosides, etc. Water-soluble synthetic polymers may also be selected, such as polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), sodium polyacrylate (PAA), polystyrene-maleate, etc., and polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymers. Preferably, water-soluble natural polymers and their derivatives are selected.

[0085] The ratio of the amount of the water-soluble polymer additive to the amount of dilution water is not greater than 1:1000; preferably, not greater than 1:800; more preferably, not greater than 1:600.

[0086] The alkaline compound includes at least one of sodium hydroxide, potassium hydroxide and ammonium hydroxide, preferably ammonium hydroxide.

[0087] Furthermore, the copper oxychloride nano-suspension dispersion with a size below 100 nanometers has a stability period of hours.

[0088] Suspensions below 100nm

[0089] In order to improve the efficacy of nano-scale copper oxychloride / mancozeb, the present invention needs to reduce its particle size as much as possible. The original intention of studying nano-pesticides is to improve the efficacy of pesticides and reduce the amount of pesticides used. The particle size of traditional pesticide preparations is usually in the micron level. Reducing it to the corresponding nanometer size spans three orders of magnitude. When it is reduced to different orders of magnitude, the number of particles increased is also different. For example, if the particle size of traditional preparations 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 the reduction in particle size will lead to different increases in the number of particles and different effects. Therefore, in order to improve the efficacy of nanopesticides, the particle size should be reduced as much as possible.

[0090] To further enhance the efficacy of nano-sized copper oxychloride / mancozeb, the present invention aims to reduce the particle size to below 100 nm. This is based on two factors. First, a size below 100 nm is the minimum size required for nanomaterials in any one dimension. Second, pesticide particles between 1 and 100 nm form a colloidal solution, appearing water-soluble and clear. When a beam of light is shone upon the solution, a well-defined beam of light is observed, consistent with the description of the Tyndall phenomenon.

[0091] Concentration of Copper Oxychloride / Zineb Nano-Suspension Dispersion

[0092] The concentration of the copper oxychloride / mancozeb nano-suspension dispersion of the present invention is affected by the dosage of the active ingredient and the amount of water used for dilution. Taking a conventional copper oxychloride / mancozeb compounded wettable powder as an example, for use in preventing and treating citrus canker, a reported dosage of the active ingredient is 185 / 75 g / mu (1 mu = 1 / 15 hectare), with a typical water consumption of 150 kg / mu. In this case, the diluted concentrations of copper oxychloride and mancozeb are 0.12% and 0.05%, respectively. Due to the small particle size and high efficacy of the nano-suspension dispersion of the present invention, the dosage can be reduced by approximately 30%, to an actual dosage of approximately 130 / 52 g / mu. The concentrations of the copper oxychloride / mancozeb nano-suspension dispersion in the dilution solution are approximately 0.087% and 0.035%, respectively.

[0093] Stable period

[0094] The copper oxychloride / Zineb nano suspension dispersion prepared by the present invention is a class of transparent, apparently water-soluble solution, but itself does not have thermodynamic stability. Therefore, the time that the nano suspension dispersion keeps the transparent state of appearance is not infinitely long, but there is a stable period. Considering the operating characteristics of the spraying operation, after the nano copper oxychloride suspension dispersion is prepared, the operating time required should be at least more than 1 hour, so that the length of the stable period time can be described in hours. Thus, the present invention proposes that the nano-level copper oxychloride suspension dispersion below 100nm has the concept of "stable period". That is, the copper oxychloride nano suspension dispersion below 100nm prepared by the present invention completes the spraying operation while the solution remains transparent, and the stable period should reach 1 hour at least.

[0095] 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.

[0096] The spraying operation was completed within 1 hour, indicating that the Nano-Copper King / Zineb suspension still maintained a transparent state, that is, the particle size was ensured to be still less than 100 nm.

[0097] Direct observation can be used to determine changes in the transparency and particle size of nano-copper oxychloride / mancozeb suspensions. During the stable period, the suspension remains transparent, with particles less than 100 nm in size. When the suspension becomes unstable, opalescence first appears, indicating that the particles are beginning to increase in size. A faint opalescence indicates that the particles in the suspension are beginning to exceed 100 nm. Gradually increasing opalescence indicates that the particles have grown to several hundred nanometers in size. Further turbidity and precipitation indicate that the particles have increased in size to the micron or millimeter level.

[0098] The present invention is applicable to the observation of the stable period of copper oxychloride suspension dispersion with a size of less than 100 nanometers at different hourly levels.

[0099] Hourly stability period

[0100] From the perspective of spraying operations:

[0101] The stabilization time is about 1 hour, which is not enough for spraying operations; a stabilization period of more than 10 hours is of little significance for pesticide formulations. Even if the liquid medicine is very stable, it is not very practical for storage and transportation due to the low pesticide content and large volume capacity.

[0102] Therefore, the stabilization time is between 1 and 10 hours, and most pesticide spraying operations can be completed easily within this time.

[0103] The hour-level stabilization period mentioned in the present invention refers to a stabilization time between 1 and 10 hours.

[0104] For the hourly stable period, further detailed division can be carried out.

[0105] The basic period for spraying operation is 1 to 5 hours; in most cases, the spraying equipment can complete the operation.

[0106] 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.

[0107] Components and additives of copper oxychloride / mancozeb nano-suspension dispersion

[0108] Traditional copper oxychloride single-ingredient and binary compound formulations typically consist of only one component and can be sprayed after dilution with water. However, the pesticide particles are typically larger than microns in size. The present invention, in order to produce a nano-scale copper oxychloride / mancozeb nanosuspension dispersion, employs at least two components. By diluting the suspension with water according to a specific method, a copper oxychloride / mancozeb nanosuspension dispersion with a particle size of less than 100 nanometers can be obtained.

[0109] Taking the three-component model as an example, the following explanation is given.

[0110] Three-component basic scheme

[0111] The basic solution of the 100nm-level copper oxychloride / mancozeb suspension of the present invention is a system generated by the mixed reaction of three components. They are:

[0112] Component A: It is composed of an aqueous solution of an alkali compound and maneb salt. Maneb salt is the precursor of maneb nanoparticles.

[0113] Component A, the alkaline compound is selected from at least one of sodium hydroxide, potassium hydroxide and ammonium hydroxide, preferably, an aqueous ammonium hydroxide solution (aqueous ammonia). The manebrite is selected from at least one of sodium manebrite, potassium manebrite and manebrite, preferably, manebrite.

[0114] Component B: It is composed of copper chloride, zinc salt solid or zinc salt aqueous solution, which is the metal salt required to generate copper oxychloride and mancozeb nanoparticles.

[0115] Component B, the zinc salt is selected from at least one of zinc sulfate, zinc acetate, zinc chloride, and zinc nitrate, preferably zinc sulfate. Component B can be used in solid form or in aqueous solution.

[0116] Component C: It is composed of at least one water-soluble surfactant, or its aqueous solution, which is an auxiliary agent that has the effects of dispersing, suspending and stabilizing the generated copper oxychloride and mancozeb nanoparticles.

[0117] Component C is an auxiliary agent composed of a water-soluble surfactant. The water-soluble surfactant can be selected from a polymer surfactant and a small molecule surfactant. Considering that the polymer surfactant has a better dispersion, suspension and stabilization effect on the crystals than the small molecule surfactant, the polymer surfactant is preferred.

[0118] Under the conditions of pre-stirring and effective stirring, the generated copper oxychloride and mancozeb particles are dispersed in a random coil morphology structure formed by the water-soluble polymer dispersant dissolved in water.

[0119] The ratio of the amount of water-soluble high molecular surfactant to the amount of dilution water is preferably not greater than 1:800.

[0120] The water-soluble polymer surfactant of the present invention is selected from natural substances and their derivatives and synthetic polymer surfactants. Preferably, it is selected from starch, cellulose, guar gum, chitosan and their derivatives; polyoxyethylene ether derivatives such as aliphatic, aliphatic aromatic, aliphatic phenolic, arylphenolic, and oleyl groups; aliphatic polyether sulfates and sulfonates; Tween and alkyl polyglycosides.

[0121] 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.

[0122] Two-component improvement plan

[0123] One of the improvements of the present invention is a copper oxychloride / mancozeb nano-suspension dispersion with a size of less than 100 nanometers, which has a stability period of hours and is a system generated by the mixing reaction of two components. They are:

[0124] Component A: An aqueous solution consisting of ammonium hydroxide, maneb, a water-soluble polymer surfactant, and water. This solution is composed of the base compound required to generate copper oxychloride (100 nanometers or less), a precursor for maneb, a water-soluble polymer surfactant for dispersion, suspension, and stabilization, and water.

[0125] Component B is composed of copper chloride required for producing copper oxychloride and zinc sulfate mixed salt solid or its aqueous solution required for producing maneb.

[0126] This improved solution is to distribute the water-soluble polymer surfactant used into component A and component B. It can be considered that component A in the two-component solution is equivalent to "component A + component C" in the three-component solution.

[0127] Reaction equation and ratio for producing copper oxychloride and mancozeb

[0128] The raw materials required to produce copper oxychloride are copper chloride and ammonium hydroxide. The generally accepted reaction formula is as follows, which can be used to determine the ratio and dosage of products and reactants:

[0129] That is, to generate 100 g mass copper: copper chloride: ammonia water = 100: 126: 50

[0130] If maneb is selected as the precursor and zinc sulfate as the zinc salt, maneb can be generated. Because zinc ions have a coordination effect, the resulting maneb structure is two maneb groups combined with one zinc ion. The reaction equation is:

[0131] That is, the ratio of Zineb: Maneb: Zinc Sulfate = 100: 126: 60 is generated for 100 g of mass.

[0132] Water-soluble polymer dispersant (additive)

[0133] (1) The transparent solution of the copper oxychloride / mancozeb nano-suspension dispersion is a ready-to-use copper oxychloride / mancozeb composite suspension. A water-soluble dispersing polymer additive is added to this solution, resulting in the copper oxychloride and mancozeb being suspended and dispersed as nanoparticles within a random coil structure formed by the polymer additive dissolved in water. Because the particles are less than 100 nanometers in size, the resulting copper oxychloride / mancozeb nano-suspension dispersion is transparent and apparently water-soluble.

[0134] (2) The water-soluble polymer additive with a dispersing effect is an important component that affects the nano-particle size of copper oxychloride and mancozeb generated when the two components are diluted and mixed, as well as whether they can be evenly dispersed and stably suspended.

[0135] (3) Water-soluble polymer additives are also polymer surfactants, generally referring to substances with relatively large molecular weight and surface activity. Compared with small molecule surfactants, polymer surfactants are less capable of reducing surface tension, but they possess other special properties, such as dispersion, suspension, emulsification, and viscosity enhancement. Water-soluble polymer surfactants can be classified according to their source into natural polymers and their derivatives and synthetic polymers. Water-soluble polymer surfactants have a hydrophobic chain structure and hydrophilic functional groups, which may be at the end or side groups, such as hydroxyl, carboxyl, carboxymethyl, sulfonic acid, sulfate, phosphoric acid, and amino groups, making them all water-soluble polymers. Water-soluble natural polymers and their derivatives include starch, cellulose and its derivatives, carboxymethyl chitosan, modified guar gum, and tea saponin. Water-soluble synthetic polymers include polyvinyl pyrrolidone, polyvinyl alcohol, sodium polyacrylate, polyacrylamide, and polystyrene-maleic anhydride copolymer. Since the main chains of water-soluble synthetic polymers are mostly carbon chains and are not easily biodegradable, from the perspective of environmental friendliness, water-soluble natural polymers and their derivatives should be selected as much as possible to minimize the impact on the ecological environment.

[0136] (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 dissolve in water. When a linear polymer is dissolved in water, its aspect ratio is very large. Instead of appearing as a straight chain, 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 face the aqueous phase, while the lipophilic chain structure curls 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 together, forming larger micelles. 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 is typically a few to tens or hundreds of nanometers. If pesticide nanocrystals form in the system, they are incorporated into the random coils under the shear force of stirring. When the pesticide nanocrystals are smaller, more nanocrystals can be dispersed within the random coils. Therefore, water-soluble polymer adjuvants can disperse and stabilize the generated nanocrystals. Traditional pesticide suspension concentrates also utilize this principle, but their pesticide particles are large, at the micron level, making them typically opaque. Due to the greater gravity of the particles, this poses a significant risk to stability. When the pesticide particle size is reduced by two to three orders of magnitude, the gravity effect on the particles is significantly reduced. Using the same water-soluble polymer surfactant, nanosuspensions with longer stability can be obtained, achieving apparent water solubility and transparency.

[0137] (5) The copper oxychloride / mancozeb nano-suspension dispersion is directly produced by the reaction of cupric chloride with ammonium hydroxide and mancozeb with zinc sulfate during the dilution process prior to use. The amount of water-soluble polymer additive used is related to the amount of copper oxychloride and mancozeb produced in the system and the amount of dilution water used. For example, when the active ingredients of copper oxychloride / mancozeb are 100 / 40 g / mu and the spraying water consumption is 100 kg / mu, the dilution concentration is 1-0.4 g / kg, respectively, which is within the spraying concentration. By controlling the amount of water-soluble polymer additive, the stability of the copper oxychloride / mancozeb nano-suspension dispersion can be adjusted. The concentration of the water-soluble polymer additive should be no less than 0.2%.

[0138] (6) The copper oxychloride / mancozeb nanosuspension is directly formed during the dilution process before spraying. The two components are directly mixed at a specific concentration and in a specific mixing method to produce the target solution. This solution not only eliminates the synthesis and purification process required by pesticide manufacturers to prepare copper oxychloride and mancozeb technicals, but also eliminates the multi-step physical processing required by pesticide formulation manufacturers to convert copper oxychloride and mancozeb technicals into traditional wettable powder formulations. The solution proposed by this invention can be directly applied to the plant protection sector of agricultural production. The process is significantly environmentally friendly and energy-efficient, significantly reducing production costs and significantly improving drug efficacy. It can also significantly reduce pesticide usage, achieving a reduced dosage and increased efficiency.

[0139] The key technologies of the present invention lie in the following aspects:

[0140] 1. Reaction of copper chloride with alkali and pH control

[0141] Copper chloride (CuCl2) can react with water-soluble bases (NaOH, KOH, and NH4OH) to produce copper oxychloride. NaOH and KOH are both strong bases, while NH4OH is a weak base. Taking NH4OH as an example, the reaction formula is as follows:

[0142] 4CuCl2+6NH4OH→CuCl2·3Cu(OH)2↓+6NH4Cl

[0143] During the preparation process, controlling the pH value has a significant impact on the reaction process and products. Copper chloride reacts rapidly with strong bases, and when the system pH is high (12-14), copper oxychloride precipitates quickly. This is detrimental to obtaining grains smaller than 100 nm. Because NH₄OH is a weak base and reacts mildly with CuCl₂, the system pH is relatively low (7-8), resulting in slower copper oxychloride precipitation and better control of grain growth rate. Mild reaction conditions are beneficial for obtaining copper oxychloride grains smaller than 100 nm.

[0144] 2. Control of reaction conditions for preparing nano copper / mancozeb

[0145] The preparation of nano-sized copper oxychloride and mancozeb involves two separate reactions: the reaction of copper chloride with ammonia, and the reaction of mancozeb with zinc sulfate. Both reactions are ionic and readily occur. The key lies in obtaining nano-sized crystals, characterized by a transparent dispersion. This involves factors such as the concentration of the two diluent components (related to the water used), the method and rate of component addition, and the stirring speed. The following reaction conditions should be considered:

[0146] (1) Component division and dilution water allocation. The principle of component division is to separate reactive components for easier packaging and ease of handling. The optimized solution is a two-component solution: one component is an aqueous solution consisting of the precursor mancozeb and ammonium hydroxide, and the other is solid copper chloride or zinc sulfate or their aqueous solutions. The dilution water volume depends on the concentration of the active ingredient and is generally greater than that of traditional pesticide formulations. The dilution ratio depends on the order of component addition—whether component A is added first, then component B, or in reverse order. Generally, the addition ratio of the added component should be smaller than that of the incoming component to facilitate thorough mixing and shorten the mixing time.

[0147] (2) Control the reaction conditions. Add the diluted solution of one component slowly dropwise to the diluted solution of the other component while stirring. The method and speed of addition are crucial for controlling the size and uniformity of the crystals. Effective stirring ensures a uniform reaction and avoids high concentrations in certain areas that can lead to crystal agglomeration and growth.

[0148] (3) Controlling the growth and stabilization of nanoparticles. The presence of a water-soluble polymer dispersant in the system is crucial. It disperses, suspends, and stabilizes the nanoparticles generated by the reaction, helping to isolate and protect them, reducing particle collisions and preventing aggregation and growth.

[0149] 3. Selection of water-soluble polymer dispersants

[0150] When preparing the copper oxychloride / mancozeb nano-dispersion, in order to prevent precipitation and maintain transparency, selecting the appropriate type and amount of water-soluble polymer additives as dispersants is one of the key technologies of the present invention. These substances can disperse and stabilize the nanoparticles, preventing them from aggregating and precipitating, thereby maintaining the transparency of the dispersion. The water-soluble polymer additives selected in the present invention include:

[0151] Water-soluble natural polymers and their derivatives. Water-soluble natural polymers and their derivatives used as dispersants include starch, cellulose, guar gum, chitosan, and their derivatives, such as carboxymethyl starch, carboxymethyl cellulose, lignin sulfonate, carboxymethyl chitosan, and modified guar gum; fatty acid derivatives, such as sodium lauryl sulfate and sodium lauryl polyether sulfate; and polyoxyethylene ether derivatives, including polyoxyethylene ethers with various aliphatic, aliphatic aromatic, aliphatic phenolic, aromatic phenolic, and oily hydrophobic groups, such as the Pereal series, OP series, Tween series, polyol series, ricinoleic acid series, and alkyl polyglycosides.

[0152] Water-soluble synthetic polymers. Water-soluble synthetic polymers include polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), polyacrylic acid salt (PAA), polyacrylamide, polystyrene-maleate, polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymers, amino silicone oil, etc.

[0153] When using these water-soluble polymer dispersants, it is important to determine the most suitable type and dosage through experimentation to achieve optimal dispersion and solution clarity. Furthermore, the selection of a dispersant should also consider the properties required by the end-use application, such as biodegradability and its impact on the ecological environment. Therefore, biodegradable natural polymers and their derivatives are preferred. It is worth noting that in most cases, a combination of different dispersants, or composite additives, is required to achieve optimal results.

[0154] Preparation method of copper oxychloride / mancozeb nano-suspension dispersion

[0155] The present invention adopts the following technical solutions, taking the convenient two-component solution as an example:

[0156] 1. Composition and preparation of the two-component solution

[0157] Component A: consists of an alkali compound (preferably ammonium hydroxide), a precursor (preferably maneb), a selected water-soluble polymer surfactant, and water. This is a mixed aqueous solution consisting of the alkali compound required to produce copper oxychloride (100 nanometers or less), the precursor to maneb, a water-soluble polymer surfactant for dispersion, suspension, and stabilization, and water.

[0158] In the preparation of component A, since water-soluble polymer additives are more difficult to dissolve in water than small molecules, they should be added into appropriate water first, stirred to dissolve, and then the precursor and alkaline compound should be added, stirred to dissolve, and a transparent aqueous solution of component A should be obtained.

[0159] Component B is composed of a mixed metal salt of copper chloride, a precursor required to produce copper oxychloride, and zinc sulfate, required to produce maneb. Component B can be a solid mixture or an aqueous solution composed of water.

[0160] To prepare component B, if component B is in solid form, the two metal salts can be mixed. If it is in solution form, the two metal salts of component B can be added to an appropriate amount of water and stirred to dissolve to obtain a transparent aqueous solution of component B.

[0161] 2. Dilute component A and component B with water according to the distribution ratio

[0162] According to the dilution water volume and the distribution ratio of the two components, dilute component A and component B in two containers of appropriate size to obtain transparent diluted aqueous solutions of component A and component B respectively.

[0163] 3. Reaction of two-component diluted aqueous solutions

[0164] Under pre-stirring, the diluted aqueous solution of component B is added to the diluted aqueous solution of component A according to a certain adding method to carry out the reaction. That is, 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 under the condition that the stirring speed is not less than the effective stirring speed.

[0165] It can also be added in the opposite way: the component B dilution is pre-stirred first, and then the component A dilution is added to the component B dilution under the condition that the stirring speed is not less than the effective stirring speed.

[0166] The generated copper oxychloride and mancozeb nanoparticles are dispersed in a random coil morphology structure formed by dissolving a water-soluble polymer dispersant in water.

[0167] Addition methods include dropwise addition, trickle addition, spray addition, intermittent addition, continuous dropwise addition, and alternating continuous and intermittent addition. Control the addition rate and stirring speed, and observe that the reaction system remains transparent until the addition of one component aqueous solution is complete.

[0168] The resulting copper oxychloride / mancozeb nanosuspension dispersion is transparent and apparently water-soluble, making it suitable for spraying against diseased crops. Observe the time it takes for the transparent dispersion to precipitate; this time interval represents the spraying period.

[0169]

Brief description of the attached drawings

[0170] Figure 1: Flowchart for preparing copper oxychloride / mancozeb nanosuspension dispersion (two components)

[0171] Figure 2: Flowchart for preparing copper oxychloride / mancozeb nanosuspension dispersion (three components)

[0172] [Implementation Method]

[0173] Example 1.

[0174] A copper oxychloride / mancozeb nanoparticle suspension dispersion can be used to control bacterial angular leaf spot on cucumbers. A reported dosage of the two active ingredients is 37 / 15 g / mu, with a dilution water requirement of 30 kg. Considering the high efficacy of nanopesticides, this example uses a copper oxychloride / mancozeb active ingredient dosage of 30 / 12 g / mu, with a dilution water requirement of 30 kg / mu.

[0175] The mass ratio of the reactants is as follows:

[0176] The dosage of each component, the distribution ratio of dilution water, and the preparation method of the solution are listed in the following table:

[0177] How to do it:

[0178] ⑴ In an appropriate container, add water in a distribution ratio of 5 / 6 (25 kg), add component A, stir and dissolve to obtain a transparent diluted aqueous solution of component A.

[0179] ⑵In another appropriate container, add water in a distribution ratio of 1 / 6 (5 kg), add component B, stir and dissolve to obtain a transparent diluted aqueous solution of component B.

[0180] ⑶ Under pre-stirring, add the diluted aqueous solution of component B to the diluted aqueous solution of component A in a continuous dropwise manner, controlling the addition speed and stirring speed to keep the system transparent until the diluted solution of component B is added.

[0181] A transparent copper oxychloride / mancozeb nano-suspension dispersion was obtained, which could be directly used for spraying cucumbers. The stability time of the copper oxychloride / mancozeb nano-suspension dispersion was observed. The stability time was 4 hours.

[0182] Example 2.

[0183] A copper oxychloride / mancozeb nanoparticle suspension can be used to control tobacco wildfire. A reported dosage of the two active ingredients is 55 / 22 g / mu, with a dilution water requirement of 30-50 kg. Considering the high efficacy of nanopesticides, this example uses a copper oxychloride / mancozeb active ingredient dosage of 40 / 18 g / mu, with a dilution water requirement of 40 kg / mu.

[0184] The mass ratio of the reactants is as follows:

[0185] The dosage of each component, the distribution ratio of dilution water, and the preparation method of the solution are listed in the following table:

[0186] How to do it:

[0187] (1) In an appropriate container, add water in a distribution ratio of 4 / 5 (32 kg), add component A, stir and dissolve to obtain a transparent diluted aqueous solution of component A.

[0188] ⑵In another appropriate container, add water in a distribution ratio of 1 / 5 (8 kg), add component B, stir and dissolve to obtain a transparent diluted aqueous solution of component B.

[0189] ⑶ Under pre-stirring, add the diluted aqueous solution of component B to the diluted aqueous solution of component A in a thin stream, control the addition speed and stirring speed, and keep the system transparent until the diluted solution of component B is added.

[0190] A transparent copper oxychloride / mancozeb nano-suspension dispersion was obtained, which can be directly used for tobacco spraying. The stability time of the copper oxychloride / mancozeb nano-suspension dispersion was observed. The stability time was 5 hours.

[0191] Example 3.

[0192] A copper oxychloride / mancozeb nanoparticle suspension can be used to control citrus canker. A reported dosage of the two active ingredients is 125 / 50 g / mu, with a dilution water requirement of 100-150 kg. Considering the high efficacy of nanopesticides, this example uses a copper oxychloride / mancozeb active ingredient dosage of 90 / 35 g / mu, with a dilution water requirement of 150 kg / mu.

[0193] The mass ratio of the reactants is as follows:

[0194] The dosage of each component, the distribution ratio of dilution water, and the preparation method of the solution are listed in the following table:

[0195] How to do it:

[0196] (1) In an appropriate container, add water in a distribution ratio of 9 / 10 (135 kg), add component C, stir and dissolve to obtain a transparent diluted aqueous solution of component C.

[0197] ⑵ Add component A to the diluted aqueous solution of component C, stir and disperse, and obtain a mixed diluted aqueous solution of "component A + component C"

[0198] ⑶ In another appropriate container, add water in a distribution ratio of 1 / 10 (15 kg), add component B, stir and dissolve to obtain a transparent diluted aqueous solution of component B.

[0199] (4) Under pre-stirring, add the diluted aqueous solution of component B to the mixed diluted aqueous solution of "component A + component C" in a continuous spraying manner, controlling the addition speed and stirring speed to keep the system transparent until the diluted solution of component B is added.

[0200] A transparent copper oxychloride / mancozeb nano-suspension dispersion was obtained, which can be directly used for spraying citrus fruits. The stability time of the copper oxychloride / mancozeb nano-suspension dispersion was observed. The stability time was 6 hours.

Claims

1. A copper oxychloride / mancozeb nano-suspension dispersion, wherein the copper oxychloride / mancozeb nano-suspension dispersion is a copper oxychloride / mancozeb nano-suspension dispersion of less than 100 nanometers, and is formed by diluting and mixing two components with water: Component A: an aqueous solution consisting of mancozeb, an alkali compound, a water-soluble polymer dispersant and water; Component B: copper chloride, zinc salt solid or zinc salt aqueous solution; Component A and component B, under the conditions of pre-stirring and effective stirring, the generated copper oxychloride particles are dispersed in a random coil morphology structure formed by the water-soluble polymer dispersant dissolved in water.

2. The copper oxychloride / zineb nano suspension dispersion according to claim 1, characterized in that The water-soluble polymer dispersant is a water-soluble natural polymer surfactant and its derivative surfactant, or a synthetic polymer surfactant.

3. The copper oxychloride / zineb nano suspension dispersion according to claim 1, characterized in that The water-soluble polymer dispersant is at least one of the following options: Water-soluble natural polymers and their derivatives, including starch, cellulose, guar gum, chitosan and their derivatives; fatty, fatty aromatic, fatty phenolic, aromatic phenolic, and oily polyoxyethylene ethers; fatty polyether sulfates and sulfonates; Tween and alkyl polyglycosides; Or water-soluble synthetic polymers, polyvinyl pyrrolidone, polyvinyl alcohol, sodium polyacrylate, polystyrene-maleate, etc., polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymers; Water-soluble natural polymers and their derivatives are preferred.

4. The copper oxychloride / zineb nano suspension dispersion according to claim 1, characterized in that The copper oxychloride / mancozeb nano-suspension dispersion has a stability period of hours.

5. The copper oxychloride / zineb nano suspension dispersion according to claim 1, characterized in that The ratio of the amount of the water-soluble surface dispersant to the amount of dilution water is not greater than 1:

800.

6. A copper oxychloride / mancozeb nano-suspension dispersion, wherein the copper oxychloride / mancozeb nano-suspension dispersion is a copper oxychloride / mancozeb nano-suspension dispersion of less than 100 nanometers, and is a system generated by a mixed reaction of three components: Component A: It is composed of an aqueous solution of an alkali compound and mancozeb salt; Component B: composed of copper chloride, zinc salt solid or zinc salt aqueous solution; Component C: composed of at least one water-soluble polymer dispersant, or its aqueous solution; The three components, under the conditions of pre-stirring and effective stirring, generate copper oxychloride particles dispersed in a random coil morphology structure formed by the water-soluble polymer dispersant dissolved in water.

7. The copper oxychloride / zineb nano suspension dispersion as claimed in claim 6, characterized in that The zinc salt is selected from at least one of zinc sulfate, zinc acetate, zinc chloride and zinc nitrate, preferably zinc sulfate.

8. The copper oxychloride / zineb nano suspension dispersion according to claim 6, characterized in that , the alkaline compound is selected from at least one of sodium hydroxide, potassium hydroxide and ammonium hydroxide, preferably an aqueous ammonium hydroxide solution.

9. The copper oxychloride / zineb nano-suspension dispersion according to claim 6, characterized in that The mancozeb salt is selected from at least one of mancozeb sodium, mancozeb potassium and mancozeb ammonium, preferably mancozeb ammonium.

10. The copper oxychloride / zineb nano suspension dispersion according to claim 6, characterized in that The copper oxychloride / mancozeb nano-suspension dispersion has a stability period of hours.

11. The copper oxychloride / zineb nano suspension dispersion according to claim 6, characterized in that , the water-soluble polymer dispersant is a surfactant selected from natural substances and their derivatives and synthetic polymers; Preferably, it is selected from starch, cellulose, guar gum, chitosan and its derivatives; aliphatic, aliphatic aromatic, aliphatic phenolic, aromatic phenolic, oleyl polyoxyethylene ether; aliphatic polyether sulfate, sulfonate; Tween, alkyl polyglycoside.

12. A method for preparing a copper oxychloride / mancozeb nano-suspension dispersion, characterized in that , the component A dilution is pre-stirred first, 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 copper oxychloride / mancozeb nano-suspension dispersion; Alternatively, the component B dilution is pre-stirred first, and then the component A dilution is added to the component B dilution under the condition that the stirring speed is not less than the effective stirring speed to form the copper oxychloride / mancozeb nano-suspension dispersion; Component A: an aqueous solution consisting of mancozeb, an alkali compound, a water-soluble polymer dispersant and water; Component B: copper chloride, zinc salt solid or zinc salt aqueous solution; The generated copper oxychloride particles are dispersed in a random coil morphology structure formed by dissolving a water-soluble polymer dispersant in water.

13. The preparation method according to claim 12, characterized in that ,The adding methods include intermittent adding, continuous dripping adding, and continuous or intermittent spraying adding.

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