Copper oxychloride / metalaxyl-m NANO suspension dispersion

Abstract

The present invention relates to the field of nano pesticides, and in particular to compounding of a pesticide variety insoluble in water and solvents with a pesticide variety soluble in solvents, and preparation of a suspension dispersion having a particle size of less than 100 nanometers. The copper oxychloride / metalaxyl-M nano suspension dispersion is a nano suspension dispersion in which copper oxychloride crystal grains are dispersed in a random coil morphological structure formed by a water-soluble polymer dispersant being dissolved in water and metalaxyl-M is solubilized in nano-micelles.

Description

Copper Oxychloride / Metalaxyl Nano-Emulsion Dispersion

Technical field

[0001] The invention belongs to the field of nano pesticides, and particularly relates to the preparation of a suspension dispersion liquid in which an inorganic copper compound insoluble in water and solvent is compounded with a metalaxyl-M fungicide and the particle size of the suspension dispersion liquid is 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 metalaxyl-M, triazoles, mancozeb, and prochloraz can enhance control of a range of fungal diseases. However, it is important to note that not all pesticides can be safely mixed with copper oxychloride. Pesticides that chemically react with copper oxychloride or reduce its effectiveness should be avoided.

[0010] In summary, Copper Royal, a long-established copper-based fungicide, still plays an important role in modern agricultural production. Through its rational compounding and integration with other control measures, it can effectively protect crop health, reduce the overuse of single pesticide varieties, protect the environment, 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—wettable powders and suspension concentrates. The innovative approach and technical method of this invention utilizes copper chloride and a water-soluble base in a solution reaction, controlling the reaction conditions to directly produce a nano-suspension dispersion of copper oxychloride.

[0014] Another object of the present invention is to compound it with metalaxyl-M, a substance that has excellent control effects on fungal diseases, in order to improve the control effect of copper oxychloride and expand its bactericidal spectrum, so that it has a synergistic effect and reduces the amount of a single variety used. While obtaining a copper oxychloride nanosuspension dispersion, a metalaxyl-M nanoemulsion dispersion is also obtained, that is, a copper oxychloride / metalaxyl-M nanosuspension dispersion is obtained at the same time.

[0015] Another object of the present invention is to reduce the particle size of copper oxychloride / metalaxyl-M. Because copper oxychloride is 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 / metalaxyl-M nanosuspension dispersion prepared by the present invention has particles less than 100 nm, significantly reducing the particle size and thus significantly improving the efficacy of copper oxychloride / metalaxyl-M combination formulations.

[0016] Another object of the present invention is to shorten the production and formulation process of copper oxychloride. Commercially, copper oxychloride technical is first prepared by the technical manufacturer, and then the copper oxychloride / metalaxyl-M compound formulation is processed in the formulation factory. The present invention directly uses the raw materials for synthesizing copper oxychloride and metalaxyl-M nanoemulsion, utilizes the pesticide dilution process with water, and controls the reaction conditions to obtain a transparent copper oxychloride / metalaxyl-M nanoemulsion dispersion. This method integrates the synthesis and formulation processing of copper oxychloride, directly reducing the technical synthesis and purification process, formulation processing technology, and corresponding 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 / metalaxyl-M nanoemulsion dispersion that can be directly used for spraying. The dispersion is tailored to the desired spray concentration for crops based on the dilution water and the amount of product generated, allowing for direct spraying. Because the pesticide particles are less than 100 nm in size, they significantly improve efficacy and reduce pesticide usage, contributing to sustainable agricultural development.

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

[0019] Copper Oxide and Metalaxyl-M have their own different performance characteristics

[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 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 relatively low phytotoxicity. It is highly safe for crops and, when used correctly, is not likely to cause phytotoxicity. It is suitable for a variety 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] Metalaxyl-M, chemically known as N-(2,6-dimethylphenyl)-N-(methoxyacetyl)-D-alanine methyl ester, belongs to the phenylamide fungicide class. Metalaxyl-M is a fungal protein synthesis inhibitor. It primarily inhibits ribosomal RNA synthesis in pathogenic fungi, preventing fungal spore formation and mycelial growth. This deprives the pathogen of nutrients, preventing normal growth and reproduction, and ultimately leading to its death. Metalaxyl-M exhibits protective, therapeutic, and systemic activity. Its systemic activity is particularly pronounced, with both vertical and lateral transmission, allowing it to penetrate the seed coat and reach various plant parts during seed germination and seedling growth. It is commonly used as a seed treatment agent to combat a variety of soil-borne and seed-borne diseases caused by lower-level pathogens of the Oomycetes class, such as Pythium and Soft Mold. Metalaxyl-M is also known for its much higher water solubility than typical fungicides. It has selective effects on downy mildew and phytophthora in the Oomycetes. For example, it has good control effects on late blight of potato / tomato, downy mildew of grape / cucumber, blight of beet / watermelon / pepper, black shank of tobacco, etc. It can also be used to prevent and control sudden damping-off disease of various crops such as cotton and stem rot of corn.

[0022] The performance advantages of copper oxychloride and metalaxyl-M

[0023] The fungicide spectrum is wider. Copper Oxychloride is an inorganic copper protective fungicide that has preventive and therapeutic effects on a variety of fungal and bacterial diseases. Metalaxyl-M belongs to the phenylamide fungicide class, which is mainly effective against lower fungi such as downy mildew and blight. It has strong systemic properties and can be absorbed by plants and conducted in the body. It also has a good therapeutic effect on pathogens that have already invaded the plant body. After copper Oxychloride and metalaxyl-M are combined, they can prevent and treat both fungal diseases and bacterial diseases. At the same time, the preventive effect on lower fungal diseases is more prominent, and the fungicide spectrum has been greatly expanded. For example, in the cultivation of crops such as vegetables and fruit trees, the compound agent can simultaneously prevent and treat multiple diseases such as downy mildew, blight, anthracnose, bacterial angular leaf spot, etc., reducing the number of drug applications and costs.

[0024] It has both protective and therapeutic effects. Copper Oxychloride mainly plays a protective role. After being sprayed on crops, it can quickly form a protective film to prevent the invasion of pathogens, and has a good preventive effect on non-diseased plants. Metalaxyl-M has systemic conductivity and can be absorbed by plants and conducted within the body. It has a therapeutic effect on pathogens that have already invaded the plant body and can inhibit the growth and reproduction of pathogens. When copper oxychloride is combined with metalaxyl-M, it has both the protective effect of copper oxychloride and the therapeutic effect of metalaxyl-M. It can prevent diseases before they occur and treat diseases after they occur, thereby improving the prevention and control effect. For example, during the growth of crops, the use of compound agents can simultaneously prevent and treat diseases, ensuring the healthy growth of crops.

[0025] Reduced risk of drug resistance. Long-term use of a single fungicide can easily lead to pathogen resistance, reducing control effectiveness. For example, if copper oxychloride and metalaxyl-M are used alone for many years to control a certain disease, the pathogen may gradually develop resistance to the agent, reducing the control effectiveness. When copper oxychloride and metalaxyl-M are combined, due to their different mechanisms of action, they can delay the development of pathogen resistance to the agent. Pathogens need to fight two agents with different mechanisms of action simultaneously, which is more difficult, thus reducing the risk of drug resistance.

[0026] Improve the stability of the agent. Copper oxychloride is an inorganic copper preparation and is relatively stable. However, under conditions of high temperature and humidity, it is prone to decomposition and oxidation, which can affect the agent's effectiveness. Metalaxyl-M may also decompose and degrade under certain conditions, affecting the agent's activity. For example, under alkaline conditions, the stability of Metalaxyl-M decreases. Combining copper oxychloride with Metalaxyl-M can improve the agent's stability to a certain extent. The interaction between the two agents may form a more stable complex, reducing the impact of external factors on the agent.

[0027] The combination of copper oxychloride and metalaxyl can prevent and control diseases of various crops

[0028] Vegetables. Cucumber: Control downy mildew, bacterial angular leaf spot, etc. Tomato: Late blight, leaf mold, etc. Pepper: Blight, anthracnose, etc. Eggplant: Soft blight, brown streak, etc. Potato: Late blight, etc. Cabbage: Downy mildew, soft rot, etc. Cabbage: Black rot, downy mildew, etc. Fruit trees. Citrus: Canker, scab, anthracnose, etc. Apple: Ring rot, anthracnose, leaf spot, etc. Pear: Black spot, rust, ring rot, etc. Grape: Downy mildew, black pox, white rot, etc. Strawberry: Gray mold, powdery mildew, anthracnose, etc. Other crops. Tobacco: Black shank, anthracnose, etc. Flowers: Powdery mildew, downy mildew, etc.

[0029] The ratio of copper oxychloride and metalaxyl in mixture

[0030] The realization of compounding copper oxychloride and metalaxyl-M, and preparing this inorganic pesticide that is "insoluble in both water and organic solvents" and phenylamide fungicides into nanopesticide formulations, especially the realization of preparing copper oxychloride and metalaxyl-M into a suspension dispersion with a size of less than 100nm, will face huge technical challenges.

[0031] Generally speaking, the mass ratio of copper oxychloride to the active ingredients of metalaxyl-M is between 5 and 8:1.

[0032] 1. Technical Challenges

[0033] Major problems with traditional pesticide formulations include environmental pollution, pesticide accumulation in organisms, and a significant increase in pest and disease resistance. These issues stem from the outdated nature of traditional pesticide formulations, primarily due to their large particle size, which results in low efficacy, high dosages, and high residues. Nanotechnology can significantly reduce the size of pesticide particles, improve efficacy, and reduce pesticide dosage, potentially addressing these issues and minimizing the impact of pesticide use on the environment and human health.

[0034] 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.

[0035] However, pesticides containing polyvalent metal ions are insoluble in both water and organic solvents, limiting their application in nanoscale manufacturing. Copper oxychloride is one such pesticide. Current technology makes it impossible to achieve nanoscale size through traditional mechanical crushing and ultrafine grinding processes, let alone scales below 100nm. Furthermore, compounding inorganic pesticides like copper oxychloride with the phenylamide organic fungicide metalaxyl-M, which has significantly different properties, and preparing them into a transparent nano-suspension dispersion with a particle size of less than 100nm is a globally challenging problem.

[0036] 2. Innovation of the present invention

[0037] The invention uses copper chloride and a water-soluble base as reactants for generating copper oxychloride, determines 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, the stirring speed, the temperature, and the pH value), and utilizes the process of diluting the pesticide with water to prepare a transparent and stable copper oxychloride nano-suspension dispersion liquid of a certain concentration. Simultaneously, a diluted and dispersed metalaxyl-M nano-emulsion is also present in the system, thereby forming a type of copper oxychloride / metalaxyl-M nano-suspension dispersion liquid, which can be directly used in spraying operations for preventing and controlling crop diseases.

[0038] The innovative features of the present invention are as follows:

[0039] (1) Innovative preparation of a copper oxychloride / metalaxyl-M nanoemulsion dispersion. The particle size of copper oxychloride and metalaxyl-M differs from the micron-sized size of existing copper oxychloride / metalaxyl-M wettable powder formulations, with particles smaller than 100 nm, making them significantly innovative. The innovative approach to producing this nanoemulsion dispersion involves separating the two water-soluble reactants that generate copper oxychloride into two components, one of which also contains a metalaxyl-M nanoemulsion and a water-soluble polymer additive. These two aqueous solutions are subjected to a contact reaction under controlled conditions. Due to the ionic nature of the reaction, copper oxychloride molecules are rapidly generated. As they nucleate and crystallize, they tend to precipitate from the water. The present invention employs two measures: first, one or more water-soluble polymer surfactants of selected types and amounts are pre-added as dispersants to the aqueous dispersion system to form random coils in the aqueous solution; second, appropriate reaction conditions are selected, including reactant concentrations, appropriate addition method and rate, stirring speed, and pH value, to control product formation, nucleation, and crystallization rates. In this way, when copper oxychloride crystals appear in the system at very small sizes, they are evenly dispersed into the random coils formed by the polymer dispersant under stirring. This random coil network prevents the crystals from colliding with each other and growing, thereby ensuring suspension, dispersion, and stability. Furthermore, the system also undergoes a dilution process for the metalaxyl-M nanoemulsion. As long as the emulsifier concentration is not less than the critical micelle concentration, the emulsion remains stable. These two different forms of particles constitute the copper oxychloride / metalaxyl-M nanoemulsion dispersion. One is a nanocrystal, the other is a nanoemulsion particle. If the particle size is less than 100 nm, the nanoemulsion dispersion will appear transparent.

[0040] (2) The copper oxychloride / metalaxyl-M nanoemulsion dispersion exhibits excellent performance. Its exceptional performance is demonstrated by its clear, transparent appearance and apparent water solubility. This indicates that the particle size is generally below 100 nm. This not only meets the national standard for nano-product size, but is also smaller than the particle size of existing copper oxychloride / metalaxyl-M wettable powders. While the particle size of conventional wettable powders is above the micron level, the significantly reduced particle size results in a dramatically increased number of particles, allowing for full contact with the target, improving control effectiveness, and reducing dosage.

[0041] (3) The innovative preparation method for the copper oxychloride / metalaxyl-M nano-suspension dispersion combines the original copper oxychloride technical synthesis and formulation processing processes. By utilizing the pesticide dilution process, the copper oxychloride reactants are divided into three or two components, which are then mixed in a specific addition pattern to produce the copper oxychloride / metalaxyl-M nano-suspension dispersion in a single step. This process eliminates the production processes and equipment required for copper oxychloride technical synthesis and purification, as well as the wettable powder processing technology and corresponding production equipment. This streamlines the process, saving synthesis and processing costs, and eliminates the use of expensive equipment, making it easy to operate and energy-efficient.

[0042] (4) The concentration of the Copper Oxychloride / Metalaxyl-M nano-suspension dispersion can be adjusted based on crop type and disease control needs. When using the Copper Oxychloride / Metalaxyl-M nano-suspension dispersion, the amount of water used for dilution and spraying can be determined based on the crop type and growth conditions. The concentration of the active ingredient of Copper Oxychloride / Metalaxyl-M to be sprayed can then be determined based on the severity of the disease. This allows for the precise dosage of Copper Oxychloride / Metalaxyl-M and the amount of the water-soluble polymer dispersant to be used.

[0043] 3. Technical ideas of the present invention

[0044] The reactants for copper oxychloride formation can be copper chloride and an alkali compound (sodium hydroxide, potassium hydroxide, ammonium hydroxide). Both are water-soluble substances and dispersed monomolecularly in water. When the two interact, ion exchange reactions easily form copper oxychloride molecules. However, the addition of a metalaxyl-M nanoemulsion to one component does not react, but merely dilutes the system.

[0045] The above ingredients can be divided into two-component or three-component solutions, based on the principle of non-reaction within the components, simple packaging, and ease of use. Copper chloride can be used as component A, the alkaline compound as component B, and the required water-soluble polymer additive as component C. Metalaxyl-M nanoemulsion can be added to either component C or component A. For convenience, a two-component solution can also be simplified, with component C added to component A. Component A in the two-component solution becomes "component A + component C" in the three-component solution.

[0046] In the system, components A and B meet to form copper oxychloride nanocrystals. When the particles are very small and few in number, they are briefly dispersed in water. As the nanocrystals continue to form, they collide, aggregate, and grow. When the copper oxychloride particles 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, they begin to exhibit an opalescent sheen and gradually become opaque. Combined with the effects of gravity, they precipitate as large particles. To prevent this, a water-soluble polymer dispersant must be added to the system. Water-soluble polymer dispersants are typically linear macromolecules that, when dissolved in water, exist as random coils. 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. As the copper oxychloride nanocrystals initially form, the shear forces of stirring cause these water-insoluble nanocrystals to diffuse into the random coils and become loaded. This isolates and prevents the effective collision, crystal growth, precipitation, and settling of the successively generated crystals. Therefore, the random coils formed by the water-soluble polymer dispersant disperse, suspend, stabilize, and protect the copper nanoparticles. When the crystal size is below 100 nanometers, the system appears clear and transparent, and appears water-soluble.

[0047] 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 amount added per unit time and the uniformity of dispersion, 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 theoretical basis is that when the particle size is less than one-quarter of the lower limit of the visible light wavelength (400-760 nm), there is no significant refraction or reflection, and therefore the system is transparent. Conversely, if the system is opalescent or opaque, it indicates that the particle size is greater than 100 nm.

[0048] At the same time, the system is also undergoing a dilution process of the metalaxyl-M nanoemulsion. As long as the concentration of the emulsifying polymer in the system is not lower than the critical micelle concentration, metalaxyl-M will remain stably present in the solubilizing micelles, without affecting the transparency and stability of the system.

[0049] To achieve this goal, the following points must be focused on:

[0050] ⑴ Controlling the reaction speed of copper oxychloride molecules, crystallization speed, and growth speed is the key to obtaining particles smaller than 100nm. This involves factors such as the concentration of reactants in the reaction area, diffusion rate, type and amount of water-soluble polymer dispersant, dilution water volume, and pH value.

[0051] (2) The strength and selection of the alkaline compound. The formation of copper oxychloride is the reaction of copper salt and alkali. The alkali used in the traditional preparation of copper oxychloride is slaked lime, that is, calcium hydroxide. Although its alkalinity is relatively weak, its water solubility is poor and the particles are large, making it difficult to separate and control the water-soluble copper oxychloride generated by the system, which ultimately forms a larger particle precipitate. In addition to calcium hydroxide, sodium hydroxide, potassium hydroxide and ammonium hydroxide can also be used as alkaline compounds. The first two are strong bases, have a fast reaction rate with copper chloride, and are difficult to control. Ammonium hydroxide has a weak alkalinity, a slow reaction rate with copper chloride, and a relatively slow rate of copper oxychloride formation. Considering the control of the rate of copper oxychloride formation and the nucleation and crystallization growth of the particles, the present invention preferably uses ammonium hydroxide as the alkaline compound.

[0052] (3) Selection of the type and amount of water-soluble polymer additives. Copper chloride reacts with alkali to form copper oxychloride. The product is insoluble in water and will inevitably aggregate molecules in water to form crystal nuclei. The crystal nuclei continue to grow, and the final formed grains will precipitate out of the water. The purpose of the present invention is to control the grain size of the generated copper oxychloride so that it is no larger than 100nm. In order to prevent the growth of the crystal nuclei generated in water, surfactants, including polymers and small molecules, are added to change the surface properties of the crystals, reduce the surface energy of the crystals, thereby inhibiting the growth of the crystals and promoting the formation of crystal nuclei. Polymeric surfactants can also improve the dispersibility of the crystals, prevent crystal agglomeration, and make the grains suspended, dispersed, and stable.

[0053] Polymer dispersants possess 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 stems from their different morphological structures in water compared to small molecules. Due to their large molecular weight and long molecular chains, water-soluble polymers do not dissolve in water as straight chains, but rather as random coils. These random coils, dispersed in water as molecules, can range in size from a few nanometers to tens of nanometers, or even hundreds of nanometers or more, depending primarily on their molecular weight. These random coils suspend nanocrystals formed in the solution. This is due to the loose spatial structure of the random coils. Under stirring, the resulting copper oxychloride crystals enter these coils, suspending, dispersing, stabilizing, and preventing crystal aggregation, thereby preventing and controlling further crystal growth. Water-soluble polymers can be categorized by type into anionic, cationic, zwitterionic, and nonionic types. They can also be categorized by source into natural polymers and their derivatives, as well as synthetic polymers. The type and amount of water-soluble polymer dispersant to be selected and used are determined through experiments.

[0054] (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, and the local concentration will be too high. This will also accelerate the formation of crystals, and there is a possibility of aggregation between nanocrystals, 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 transparency of the system.

[0055] 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.

[0056] Explanation of terms

[0057] 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).

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] System: The so-called system refers to the system in which, during the preparation of the transparent copper oxychloride / metalaxyl-M nanoemulsion dispersion, the base reacts with copper chloride to form copper oxychloride, and the metalaxyl-M nanoemulsion is diluted, while controlling the addition method, speed, and stirring speed. The system is composed of copper chloride, the base compound, the metalaxyl-M nanoemulsion, a polymer additive, and water.

[0063] 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 formed by the ingredients should not be too large.

[0064] Ingredients: The so-called ingredients refer to the raw materials used in the present invention, including water-soluble copper chloride, alkali compound, metalaxyl-M nanoemulsion, water-soluble polymer additive and water.

[0065] 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.

[0066] 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.

[0067] Precursor: The so-called precursor refers to the parent substance used to generate the target product. Here the target product is copper oxychloride, and the precursor is copper chloride.

[0068] Particle size: Also known as particle size, this refers to the size of the copper oxychloride crystallites and metalaxyl-solubilized micelles generated in the system. Copper oxychloride particles are usually crystalline grains and do not specifically refer to the microscopic morphology of the grains.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] Addition speed: After determining the addition method, control the amount of components added with the goal of achieving effective stirring.

[0075] One of the purposes of the present invention is to overcome the shortcomings of the existing technology and provide a new idea and a new method. The process of using water as a dispersion medium for pesticide formulations, which usually needs to be diluted with water before spraying, is used to achieve the dilution of the copper oxychloride and metalaxyl-M nanoemulsion generated by the reaction of copper chloride and alkali, thereby providing an apparently water-soluble and transparent copper oxychloride / metalaxyl-M nanoemulsion dispersion that can be directly used for spraying.

[0076] The copper oxychloride / metalaxyl-M nano-suspension dispersion of the present invention can be loaded into a pesticide spraying device for spraying, and is used for preventing and controlling various diseases of fruit trees, vegetables and crops.

[0077] The copper oxychloride / metalaxyl-M nano-suspension dispersion of the present invention refers to a mixed dispersion of a copper oxychloride suspension dispersion of less than 100 nanometers and a metalaxyl-M nano-emulsion dilution; the copper oxychloride / metalaxyl-M nano-suspension dispersion of less than 100 nanometers is formed by diluting and mixing at least two components with water:

[0078] Component A: an aqueous solution consisting of precursor copper chloride, metalaxyl-M nanoemulsion, a water-soluble polymer dispersant and water;

[0079] Component B: aqueous solution of alkaline compound.

[0080] Component A and component B, under the conditions of pre-stirring and effective stirring, generate copper oxychloride particles dispersed in a random coil morphology structure formed by dissolving a water-soluble polymer dispersant in water.

[0081] The water-soluble polymer dispersant is a natural polymer surfactant and its derivative surfactant, or a synthetic polymer surfactant.

[0082] The water-soluble polymer surfactant 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, and oleyl polyoxyethylene ethers; aliphatic polyether sulfates and sulfonates; Tween and alkyl polyglycosides. Water-soluble synthetic polymers such as polyvinyl pyrrolidone, polyvinyl alcohol, sodium polyacrylate, polystyrene-maleate, and polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymers may also be selected. Preferably, water-soluble natural polymers and their derivatives are selected.

[0083] The ratio of the amount of the water-soluble polymer additive to the amount of dilution water is no greater than 1:1000, preferably no greater than 1:800, and more preferably no greater than 1:600. The amount of dilution water includes all the water in the system.

[0084] The alkaline compound includes at least one of sodium hydroxide, potassium hydroxide and ammonium hydroxide, preferably ammonium hydroxide.

[0085] Furthermore, the copper oxychloride nano-suspension dispersion with a size below 100 nanometers has a stability period of hours.

[0086] Nano-suspension emulsion below 100nm

[0087] In order to improve the efficacy of nano-scale copper oxychloride / metalaxyl-M, the present invention needs to reduce its particle size 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 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.

[0088] To further enhance the efficacy of nano-scale copper oxychloride / metalaxyl-M, the present invention reduces its particle size to below 100 nm. This approach is based on two factors. First, a size below 100 nm is the minimum size required for nanomaterials in any single dimension. Second, pesticide particles between 1 and 100 nm form a colloidal solution, are apparently water-soluble, and are clear and transparent. When a beam of light is irradiated into the solution, a clearly defined beam of light is observed, consistent with the description of the Tyndall phenomenon and serving as a marker for the target product.

[0089] Concentration of copper oxychloride / metalaxyl nanoemulsion dispersion

[0090] The concentration of the copper oxychloride / metalaxyl-M nano-suspension dispersion of the present invention is affected by the active ingredient and the amount of water used for dilution. Taking a conventional copper oxychloride / metalaxyl-M wettable powder for controlling grape downy mildew as an example, a reported dosage of the active ingredient is 75 / 15 g / mu (1 mu = 1 / 15 hectare), and a typical water consumption is 150 kg / mu. In this case, the dilution concentrations of copper oxychloride and metalaxyl-M are 0.05% and 0.01%, 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 at least about 20%. The actual dosage is approximately 60 / 12 g / mu, and the concentrations of the copper oxychloride / metalaxyl-M nano-suspension dispersion in the dilution solution are approximately 0.04% and 0.008%, respectively.

[0091] Stable period

[0092] The copper oxychloride / metalaxyl-M nano-suspension dispersion prepared by the present invention is a type of colloidal solution that is transparent in appearance and appears water-soluble, but it is not a thermodynamically stable solution. Therefore, the time for the nano-suspension dispersion to remain transparent is not infinite, but rather there is a stable period. Considering the operational characteristics of the spraying operation, after the nano copper oxychloride / metalaxyl-M nano-suspension dispersion is prepared, the required operating time should be at least 1 hour. This can be used to describe the length of the stable period in hours. Therefore, the present invention proposes the concept of a "stable period" for nano-scale copper oxychloride suspension dispersions below 100 nm. That is, the copper oxychloride / metalaxyl-M nano-suspension dispersion prepared by the present invention below 100 nm can complete the spraying operation within the period when the solution remains transparent, and the stable period should be at least 1 hour.

[0093] 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.

[0094] The spraying operation was completed within 1 hour, indicating that the Nano-Copper King / Metalaxyl-M emulsion dispersion remained transparent, that is, the particle size was ensured to be still less than 100 nm.

[0095] Direct observation can be used to determine changes in the transparency and particle size of nano-copper oxychloride / metalaxyl-M suspension emulsions. 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 emulsion is beginning to exceed 100 nm. Gradually increasing opalescence indicates that the particle size has increased to several hundred nanometers. Further turbidity and precipitation indicate that the particle size has increased to the micron or millimeter level.

[0096] The present invention is applicable to the observation of the stable period of copper oxychloride / metalaxyl-M suspension dispersion liquid with a size below 100 nanometers at different hourly levels.

[0097] Hourly stability period

[0098] From the perspective of spraying operations:

[0099] 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.

[0100] Therefore, the stabilization time is between 1 and 10 hours, and most pesticide spraying operations can be completed easily within this time.

[0101] The hour-level stabilization period mentioned in the present invention refers to a stabilization time between 1 and 10 hours.

[0102] For the hourly stable period, further detailed division can be carried out.

[0103] The basic period for spraying operation is 1 to 5 hours; in most cases, the spraying equipment can complete the operation.

[0104] 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.

[0105] Components and additives of copper oxychloride / metalaxyl nanoemulsion dispersion

[0106] 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. To produce a nanoscale copper oxychloride / metalaxyl-M nanosuspension dispersion, the present invention utilizes at least two components. By diluting the suspension with water according to a specific method, a copper oxychloride / metalaxyl-M nanosuspension dispersion with a particle size of less than 100 nanometers can be obtained.

[0107] Taking the three-component solution as an example, the following explanation is given.

[0108] Three-component basic scheme

[0109] The basic solution of the copper oxychloride / metalaxyl-M suspension dispersion of less than 100 nanometers described in the present invention is a system generated by the mixing reaction of three components. They are:

[0110] Component A: consists of copper chloride, metalaxyl-M nanoemulsion and water.

[0111] Component A is a transparent aqueous solution containing copper chloride, a precursor of copper oxychloride, and metalaxyl-M nanoemulsion. The copper oxychloride is dissolved in the water, while the metalaxyl-M nanoemulsion is present in the solubilizing micelles of the emulsion.

[0112] Component B: It is composed of an alkali compound or its aqueous solution. This is the alkali compound required to produce copper oxychloride.

[0113] Component B, the alkaline compound is selected from ammonium hydroxide, sodium hydroxide, potassium hydroxide, preferably ammonium hydroxide. Component B can be a solid (for strong bases) or an aqueous solution. Ammonium hydroxide can only be an aqueous solution.

[0114] Component C: It is composed of at least one water-soluble surfactant, or its aqueous solution. It is an auxiliary agent that disperses, suspends and stabilizes the generated copper oxychloride nanoparticles, and is also an emulsifier for diluting the metalaxyl-M nanoemulsion.

[0115] 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 nanocrystals than the small molecule surfactant, the polymer surfactant is preferred.

[0116] Another possible form of component C is to consist of a water-soluble surfactant and a metalaxyl-M nanoemulsion. In order to reduce the viscosity, a proper amount of water can be added.

[0117] 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 dissolving a water-soluble polymer dispersant in water.

[0118] The ratio of the amount of water-soluble high molecular surfactant to the amount of dilution water is preferably not greater than 1:800, more preferably not greater than 1:600.

[0119] 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.

[0120] In order to simplify the components and make packaging, storage, transportation and water dilution reaction operations simpler, the above three-component system can be combined into two components.

[0121] Two-component improvement plan

[0122] One of the improvements of the present invention is a nano-suspension dispersion of copper oxychloride / metalaxyl-Methyl at a level below 100 nanometers, which has a stability period of hours and is a system generated by the mixing reaction of two components. They are:

[0123] Component A: An aqueous solution consisting of copper chloride, metalaxyl-M nanoemulsion, a water-soluble polymer surfactant, and water. This solution is composed of copper chloride (precursors for copper oxychloride / metalaxyl-M) and metalaxyl-M, which are required to generate copper oxychloride / metalaxyl-M particles sized below 100 nanometers. A water-soluble polymer surfactant acts as a dispersion, suspension, and stabilizer, and water.

[0124] Component B is composed of an aqueous solution of the base compound required to form copper oxychloride, or its solid form (for strong bases). Ammonium hydroxide can only be in the form of an aqueous solution.

[0125] This improved solution is to distribute the water-soluble polymer surfactant used into component A. It can be considered that component A in the two-component solution is equivalent to "component A + component C" in the three-component solution.

[0126] The reaction equation and ratio of copper oxychloride

[0127] 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:

[0128] That is, to generate 100 g mass copper: copper chloride: ammonia water = 100: 126: 50

[0129] Water-soluble polymer dispersant (additive)

[0130] (1) The transparent dispersion of copper oxychloride / metalaxyl-M produced by "tank mixing" is a ready-to-use copper oxychloride / metalaxyl-M nanosuspension dispersion. A water-soluble polymeric additive with dispersing properties is added to this solution, resulting in the copper oxychloride being dispersed and suspended at nanoscale levels within the polymeric additive solution. Because the particles are less than 100 nanometers in size, the resulting copper oxychloride / metalaxyl-M nanosuspension dispersion is transparent and apparently water-soluble.

[0131] (2) The water-soluble polymer additive with a dispersing effect is an important component that determines whether the nano-crystal size of copper oxychloride generated when the two components are diluted and mixed can be evenly suspended and dispersed, and whether the metalaxyl-M nanoemulsion can be stable.

[0132] (3) Water-soluble polymer additives are also polymer surfactants, generally referring to substances with relatively high molecular weight and surface activity. Compared to 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, either at the end or at the side, such as hydroxyl, carboxyl, carboxymethyl, sulfonic acid, sulfate, phosphoric acid, and amino groups, making them water-soluble polymers. Water-soluble natural polymers and their derivatives include starch, cellulose, chitosan, guar gum, tea saponin, and its derivatives. Water-soluble synthetic polymers include polyvinyl pyrrolidone, polyvinyl alcohol, sodium polyacrylate, polyacrylamide, polystyrene-maleic anhydride copolymer, and polyoxyethylene-polyoxypropylene-polyoxyethylene. The main chains of water-soluble synthetic polymers are mostly carbon chains, which are not easily biodegradable. From the perspective of environmental friendliness, we should try to choose biodegradable synthetic polymers, as well as water-soluble natural polymers and their derivatives.

[0133] (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 nanoparticles are generated in the system, they are incorporated into the random coils under the shear force of stirring. 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 large, at the micron level, making them generally opaque. Furthermore, the large weight of the particles poses significant stability risks. When the pesticide particle size is reduced by two to three orders of magnitude, the weight of 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.

[0134] (5) The copper oxychloride / metalaxyl-M nano-suspension dispersant is directly produced by the reaction of copper chloride and ammonium hydroxide during the dilution process with water before use. The amount of water-soluble polymer additive used is related to the amount of copper oxychloride produced in the system and the amount of dilution water. For example, when the active ingredient of copper oxychloride / metalaxyl-M is 75 / 15 g / mu and the spraying water volume is 100 kg / mu, the dilution concentration is 0.75 / 0.15 g / kg, which is within the spraying concentration. By controlling the amount of water-soluble polymer additive, the stability of the copper oxychloride / metalaxyl-M nano-suspension dispersion can be adjusted. The concentration of the water-soluble polymer additive should not be less than 0.2%.

[0135] (6) The copper oxychloride / metalaxyl-M nano-suspension dispersion is directly generated during the dilution process before spraying. This is achieved by mixing the two components at a specific concentration and in a specific mixing method. This innovative method not only eliminates the need for the synthesis and purification process of copper oxychloride technical preparations by pesticide manufacturers, but also eliminates the multi-step process of converting copper oxychloride and metalaxyl-M technicals into traditional wettable powders by pesticide formulation manufacturers. The solution proposed by this invention can be directly applied to the plant protection process of agricultural production. This process is environmentally friendly and energy-saving, reducing production costs while significantly improving drug efficacy and reducing dosage, thereby achieving a reduction in dosage and increased efficiency.

[0136] FIG1 is a flow chart of the present invention for preparing copper oxychloride nano suspension by diluting with water.

[0137] The key technologies of the present invention lie in the following aspects:

[0138] 1. Reaction of copper chloride with alkali and pH control

[0139] 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:

[0140] 4CuCl2+6NH4OH→CuCl2·3Cu(OH)2↓+6NH4Cl

[0141] During preparation, controlling the pH value has a significant impact on the reaction process and products. Copper chloride reacts rapidly with strong bases, and high system pH values, ranging from 12 to 14, result in the rapid formation of copper oxychloride precipitates. This hinders the production of crystals smaller than 100 nm. Because NH₄OH is a weak base and reacts mildly with CuCl₂, the system pH is relatively low, ranging from 7 to 8, resulting in a slower formation of copper oxychloride precipitates and thus helping to control the grain growth rate. Mild reaction conditions are beneficial for controlling grain size when considering the production of copper oxychloride crystals smaller than 100 nm. A lower alkaline pH also contributes to the stability of copper oxychloride / metalaxyl-M formulations.

[0142] 2. Control of reaction conditions for preparing nano-copper oxaline / metalaxyl

[0143] The preparation of nano-sized copper oxychloride and metalaxyl-M is a separate process. The reaction between copper chloride and ammonia is an ionic reaction and is easy to occur. The key lies in obtaining nano-sized crystals, as evidenced by a transparent dispersion. Metalaxyl-M nanoemulsion, on the other hand, is a dilution process with water. The former involves the concentration of the two components (related to the water used), the method and speed of component addition, and the stirring speed, while the latter involves ensuring the sufficient amount of water-soluble polymer additive. Therefore, the following reaction conditions need to be considered:

[0144] (1) Component division and dilution water allocation. The principles for component division are, first, that the reacting components must be separated into different compartments, and second, that this facilitates packaging and ease of operation. The optimized solution is a two-component solution: one consisting of the precursor copper chloride, a metalaxyl-M nanoemulsion, a water-soluble polymer dispersant, and water; the other an alkaline aqueous solution. The amount of dilution water depends on the concentration of the active ingredient in the product. The dilution ratio is determined by the order in which the components are added—whether component A is added before component B, or in reverse order. Generally, the ratio of the added component should be smaller than that of the incoming component to facilitate thorough mixing and shorten the preparation time.

[0145] (2) Control reaction conditions. Slowly add one dilution to the other under pre-stirring. This can be done dropwise, by spraying, or as a trickle. The method and speed of addition are crucial for controlling grain size and uniformity. Effective stirring ensures a uniform reaction and prevents high concentrations in the reaction zone, which can lead to grain aggregation and growth.

[0146] (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 the nanoparticles and nano-latex particles, reducing particle collisions and preventing aggregation and growth.

[0147] 3. Selection of water-soluble polymer dispersants

[0148] When preparing the copper oxychloride / metalaxyl-M nano-suspension dispersion, selecting the appropriate type and amount of water-soluble polymer additives as dispersants to prevent precipitation and maintain transparency is one of the key technologies of the present invention. These substances can disperse and stabilize the nanoparticles, preventing their aggregation and precipitation, thereby maintaining the transparency of the dispersion. The water-soluble polymer additives selected in the present invention include:

[0149] 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, ammonium lauryl polyether sulfate, ammonium oleate, ammonium linoleate, and ammonium ricinoleate; and polyoxyethylene ether derivatives, such as polyoxyethylene ethers with various hydrophobic groups, such as aliphatic, aliphatic aromatic, aliphatic phenolic, arylphenolic, and oleyl groups, such as the Pereal series, OP series, Tween series, polyol series, ricinoleic acid series, and alkyl polyglycosides.

[0150] Water-soluble synthetic polymers. Water-soluble synthetic polymers include polyvinyl pyrrolidone, polyvinyl alcohol, polyacrylic acid salts, polyacrylamide, polystyrene-maleic acid salts, polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymers, and the like.

[0151] 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.

[0152] Preparation method of copper oxychloride / metalaxyl nano-suspension dispersion

[0153] The present invention adopts the following technical solutions, taking the convenient two-component solution as an example:

[0154] 1. Composition and preparation of the two-component solution

[0155] Component A: Composed of the precursor copper chloride, a metalaxyl-M nanoemulsion, a selected water-soluble polymer dispersant, and water. This aqueous solution consists of the metallic copper compound required to generate copper oxychloride particles sized below 100 nanometers, metalaxyl-M solubilized with nanoemulsion particles, and a water-soluble polymer dispersant for dispersion, suspension, and emulsification.

[0156] In the preparation of component A, since the water-soluble polymer additive is more difficult to dissolve in water than small molecules, it should be added to the water in the compounding ratio first, stirred to dissolve, and then the precursor is added, stirred to dissolve, and then the metalaxyl nanoemulsion is added, stirred and dispersed to obtain a transparent aqueous solution of component A.

[0157] Component B consists of an aqueous solution of ammonium hydroxide required to form copper oxychloride. Component B can also be diluted with water.

[0158] 2. Dilute component A and component B with water according to the distribution ratio

[0159] Determine the dilution amount based on the crop type being treated. Proportionate the water according to the two-component formula. Select two appropriately sized containers and dilute Component A and Component B. Obtain transparent diluted aqueous solutions of Component A and Component B, respectively.

[0160] 3. Reaction of two-component diluted aqueous solutions

[0161] 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.

[0162] 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.

[0163] The generated copper oxychloride particles are dispersed in a random coil morphology structure formed by dissolving a water-soluble polymer dispersant in water.

[0164] The addition method includes dropwise addition, trickle addition, spray addition, intermittent addition, continuous dropwise addition, continuous and intermittent addition, etc. Control the addition rate and stirring speed, and observe that the reaction system remains transparent until the aqueous solution of the added component is completely added.

[0165] The resulting copper oxychloride / metalaxyl-M nanoemulsion dispersion is clear, 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.

[0166]

Brief description of the attached drawings

[0167] Figure 1: Flowchart for the preparation of copper oxychloride / metalaxyl-M nanoemulsion dispersion (two components)

[0168] Figure 2: Flowchart for the preparation of copper oxychloride / metalaxyl-M nanoemulsion dispersion (three components)

[0169] [Implementation Method]

[0170] Example 1.

[0171] A copper oxychloride / metalaxyl-M nanoemulsion dispersion can be used to control bacterial angular leaf spot on cucumbers. One reported dosage of the two active ingredients is 40 / 5 g / mu, with a dilution water requirement of 30-50 kg. Considering the high efficacy of nanopesticides, this example uses a copper oxychloride / metalaxyl-M active ingredient dosage of 30 / 4 g / mu, with a dilution water requirement of 40 kg / mu.

[0172] The mass ratio of the reactants is as follows:

[0173] The dosage of each component, the distribution ratio of dilution water, and the preparation method of the solution are listed in the following table:

[0174] How to do it:

[0175] ⑴ In an appropriate container, add water in a distribution ratio of 7 / 8 (35 kg), add component A, stir and dissolve to obtain a transparent component A dilution solution.

[0176] ⑵In another appropriate container, add water in a distribution ratio of 1 / 8 (5 kg), add component B, stir and dissolve to obtain a transparent diluted aqueous solution of component B.

[0177] 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.

[0178] A transparent copper oxychloride / metalaxyl-M nano-suspension dispersion was obtained, which can be directly used for spraying cucumbers. The stability time of the copper oxychloride / metalaxyl-M nano-suspension dispersion was observed and the stability time was 4 hours.

[0179] Example 2.

[0180] A copper oxychloride / metalaxyl-M rice suspension dispersion can be used to control downy mildew in grapes. One reported dosage of the two active ingredients is 75 / 15 g / mu, with a dilution water requirement of 100-150 kg. Considering the high efficacy of nanopesticides, this example uses copper oxychloride / metalaxyl-M in dosages of 60 / 12 g / mu and a dilution water requirement of 150 kg / mu.

[0181] The mass ratio of the reactants is as follows:

[0182] The dosage of each component, the distribution ratio of dilution water, and the preparation method of the solution are listed in the following table:

[0183] How to do it:

[0184] ⑴ In an appropriate container, add water in a distribution ratio of 14 / 15 (140 kg), add component C, stir to dissolve and disperse, and obtain a transparent component C dilution solution.

[0185] ⑵ Add component A to the diluted solution of component C, stir and dissolve to obtain a transparent mixed diluted aqueous solution of "component A + component C".

[0186] ⑶ In another appropriate container, add water in a distribution ratio of 1 / 15 (10 kg), add component B, stir and dissolve to obtain a transparent diluted aqueous solution of component B.

[0187] (4) Under pre-stirring, add the component B dilution to the mixed dilution 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 component B dilution is added.

[0188] A transparent copper oxychloride / metalaxyl-M nano-suspension dispersion was obtained, which can be directly used for spraying grapes. The stability time of the copper oxychloride / metalaxyl-M nano-suspension dispersion was observed. The stability time was 5 hours.

Claims

1. A copper oxychloride / metalaxyl nano-suspension dispersion, wherein the copper oxychloride / metalaxyl nano-suspension dispersion is a copper oxychloride / metalaxyl 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 copper chloride, metalaxyl-M nanoemulsion, a water-soluble polymer dispersant and water; Component B: aqueous solution of alkaline compound; Component A and component B, 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.

2. The copper oxychloride / metalaxyl 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 / metalaxyl 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, alkyl polyglycosides, etc. Or water-soluble synthetic polymers, polyvinyl pyrrolidone, polyvinyl alcohol, sodium polyacrylate, polystyrene-maleate, polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymers; Water-soluble natural polymers and their derivatives are preferred.

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

5. The copper oxychloride / metalaxyl 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. The copper oxychloride / metalaxyl-M nano-suspension dispersion according to claim 1, 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.

7. The copper oxychloride / metalaxyl nano-suspension dispersion according to claim 6, characterized in that When the alkaline compound is ammonium hydroxide, the mass ratio of copper chloride to ammonium hydroxide required to generate 100 grams of copper oxychloride is: Copper oxychloride: cupric chloride: ammonia water = 100: 126:

50.

8. A copper oxychloride / metalaxyl nano-suspension dispersion, wherein the copper oxychloride / metalaxyl nano-suspension dispersion is a copper oxychloride / metalaxyl nano-suspension dispersion of less than 100 nanometers, and is a system generated by a mixed reaction of three components: Component A: consists of copper chloride, metalaxyl-M nanoemulsion and water; Component B: composed of an alkaline compound or its 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, the generated copper oxychloride particles are dispersed in a random coil morphology structure formed by the water-soluble polymer dispersant dissolved in water.

9. The copper oxychloride / metalaxyl-M nano-suspension dispersion according to claim 8, 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.

10. The copper oxychloride / metalaxyl-M nano-suspension dispersion according to claim 8, characterized in that The copper oxychloride / metalaxyl nano-suspension dispersion has a stable period of hours.

11. The copper oxychloride / metalaxyl-M nano-suspension dispersion according to claim 8, 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; polyoxyethylene ether derivatives such as aliphatic, aliphatic aromatic, aliphatic phenolic, aromatic phenolic, and oleyl; aliphatic polyether sulfates and sulfonates; Tween and alkyl polyglycosides.

12. A method for preparing a copper oxychloride / metalaxyl-M 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 / metalaxyl-M 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 / metalaxyl-M nano-suspension dispersion; Component A: an aqueous solution consisting of copper chloride, metalaxyl-M nanoemulsion, a water-soluble polymer dispersant and water; Component B: aqueous solution of alkaline compound; 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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