bordeaux mixture / organosulfur fungicide nanosuspension dispersion

Abstract

The present invention belongs to the field of nano-pesticides, in particular to the preparation of a suspension of a water and solvent insoluble pesticide having a particle size of less than 100 nm, especially less than 50 nm. A nano-suspension of basic copper sulphate particles in a water soluble polymeric dispersant, present in a random coil conformation in water.

Description

Bordeaux mixture / organic sulfur fungicide nano-suspension dispersion

Technical field

[0001] The invention belongs to the field of nano pesticides, and particularly relates to the preparation of a suspension dispersion of a metal-containing compound pesticide insoluble in water and organic solvents and having 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] Bordeaux mixture is a typical inorganic compound pesticide. Over the past century, it has played a significant role in controlling a variety of fungal diseases in plants. It contains no harmful impurities, is less susceptible to pesticide damage, is rain-resistant, and lacks resistance. It can be used in combination with certain other pesticides and remains a widely used broad-spectrum, protective fungicide. The active ingredient in Bordeaux mixture is basic copper sulfate, which has an extremely low solubility in water, only 1.06 mg / L. Furthermore, the traditional raw material used in its preparation, calcium hydroxide, is also poorly water-soluble. The resulting mixture is a light blue, viscous suspension with particle sizes ranging from microns to millimeters. For ease of use, companies prepare basic copper sulfate as a solid and process it into formulations, primarily wettable powders, with a smaller amount of suspension concentrates. The particle sizes of these formulations range from tens to tens of microns. As with other traditional pesticide formulations, the large particle size limits Bordeaux mixture's efficacy and also requires a larger dosage per unit area.

[0006] Bordeaux mixture is an ancient and widely used agricultural fungicide, primarily composed of a mixture of copper sulfate, slaked lime (calcium hydroxide), and water. This mixture is particularly effective in preventing and controlling fungal infections on plants such as grapevines, potatoes, peaches, apples, and bananas. Despite its importance in organic farming, Bordeaux mixture's use has raised some environmental concerns. The long-term, large-scale application of copper-containing preparations is bound to have an impact and harm on the ecological environment. In particular, the accumulation of copper, its primary component, can lead to soil and water contamination, as well as potential toxicity to ecosystem organisms such as fish and earthworms.

[0007] High concentrations of copper are used to control fungal and bacterial plant diseases. It is the only product that can control downy mildew caused by the fungus Fischer-Ribes. At lower concentrations, copper is an essential trace nutrient for plants and animals. Most crops require copper as a micronutrient, and the dosage is substantial. For crops grown in acidic organic soils, application concentrations range from 3.4 to 6.7 kg / hectare or 2.0 to 3.4 kg / hectare. For faster onset, foliar sprays of 8 g / L of copper ion are also used. The continued and extensive use of copper preparations for plant disease control and as a nutrient inevitably pollutes the environment and affects plant and animal health. Developed countries around the world are currently working to reduce the use of copper-containing preparations. European Commission Regulation (EC) 889 / 2008 stipulates copper dosages for organic agriculture, recommending a maximum of 1 kg / hectare per treatment, with a maximum of 6 kg / hectare / year. Further work is underway to reduce the maximum permissible copper concentration. A survey conducted in 12 European countries showed that copper use in organic farming was 3,258 tons per year, a reduction of 52% of the permitted annual dosage. China has not yet put this on the agenda, but judging by the development trend, reducing the use of copper preparations is imperative globally.

[0008] Europe is concerned about the environmental impacts of the copper content of Bordeaux mixture, particularly the accumulation of copper ions in soil and its long-term environmental impacts. Because copper ions can accumulate in organisms, most EU countries have banned the use of Bordeaux mixture. Only a few countries, including Belgium, Cyprus, France, Greece, Hungary, Italy, Malta, Portugal, Romania, and Slovenia, still allow its use.

[0009] Reducing the particle size of copper-containing formulations, thereby improving efficacy and reducing dosage, is undoubtedly an effective approach to addressing the global copper pollution problem. For over a century, Bordeaux mixture, a traditional and widely used pesticide with protective properties, was largely unappreciated, as its particle size impacted control effectiveness and increased dosage. With increasing understanding of pesticide formulations and advancements in innovative technology, the development of clear, transparent Bordeaux mixture (with particle sizes as small as 100nm) at sprayable concentrations has become a pressing issue.

[0010] No data were found on the preparation of nanoscale Bordeaux mixture suspensions. Nanotechnology can be used to prepare copper formulations to improve the efficiency of Bordeaux mixture and reduce its environmental impact. The preparation of nanoparticles typically involves reducing copper or its compounds to nanoscale. Such particles may have higher reactivity and better bioavailability due to their increased surface area, potentially improving the environmental friendliness of Bordeaux mixture and enhancing its antifungal efficacy.

[0011] In summary, Bordeaux mixture is an effective agricultural fungicide, but its use is subject to certain restrictions due to environmental considerations. This makes it even more necessary to apply nanotechnology to improve its efficiency and reduce its environmental impact. The present invention is an innovative technology that explores these methods.

[0012] Existing technology:

[0013] The following prior art related to the present invention was found in the literature search:

[0014] 1. “Preparation of Sodium Lauryl Sulfate-Bordeaux Mixture Composite Material and Its Antibacterial and Synergistic Properties” (Yu Zhuanni, Yu Liangmin, Wang Qiang, Modern Chemical Industry, 2014, 34(11):91-94)

[0015] This paper reports a method for preparing Bordeaux mixture using conventional techniques, except that sodium dodecyl sulfate (SDS) is added to the copper sulfate solution and then poured into the Ca(OH)2 solution in several portions. When 0.3 g / L of SDS is added, the resulting solids are hollow, coil-like structures with a particle size of 3 to 5 μm, a d(0.9) of 77.306 μm, and a suspension ratio of 90.1%.

[0016] The differences between this technical solution and the present invention are: (1) the SDS used in this technology is a small molecule and a typical anionic surfactant containing sodium ions; while the present patent application uses alkyl ether sulfates (primarily ammonium salts) and water-soluble polymer additives compounded with non-ionic surfactants. The former also has a polyoxyethylene ether structure in its molecule, so it has the properties of both non-ionic and anionic surfactants. (2) The primary product prepared by this technology is a basic copper sulfate solid with a hollow coil-like structure of 3-5μm and a d(0.9) of 77.306μm. The present patent application prepares a Bordeaux mixture nanosuspension dispersion with a particle size of less than 100nm.

[0017] 2. “Study on the preparation of nano basic copper sulfate fungicide by uniform precipitation method” (Yi Qiushi, Pesticides, 2001, 40(8):20-22)

[0018] The method disclosed in this technology is to use copper oxide as raw material, react it with ammonia water and ammonium sulfate, evaporate the ammonia under strong boiling conditions to obtain a solid product, and wash it with water and ethanol to obtain solid basic copper sulfate.

[0019] This technical proposal differs significantly from the content of the present patent application, including the reactants used, preparation methods and conditions, and product morphology. The described "nanoparticle basic copper sulfate" is prepared, but particle size data is not provided. The aggregated particles in the electron microscope photographs are so large that the scale cannot be discerned. It also states that "the prepared nanoparticle basic copper sulfate, when mixed in water containing a small amount of dispersant at a concentration of 1-5‰, is highly dispersed into a nearly translucent state." Based on common sense regarding colloidal solutions, the particle size of "translucent" particles should be over several hundred nanometers, or close to micrometers. Therefore, this technology cannot produce a strictly nanoscale basic copper sulfate suspension.

[0020] 3. "Preparation and Mechanism of Nano-Basic Copper Sulfate Suspension Agent" (Gao Mengmeng, Master's Thesis, Shenyang Agricultural University, 2021)

[0021] The dissertation states that a 40% nanometer basic copper sulfate suspension was prepared using commercially available "nano basic copper sulfate" powder (particle size not specified) by selecting several additives and grinding process conditions. However, the particle size of the basic copper sulfate was not given in the prepared sample. The size data measured for the ground sample is as follows: 50 The particle size distribution of the copper sulfate suspension (μm) ranged from 2.09 to 2.87 μm. The particle size distribution was as follows: <5 μm, 98.2% to 91.21%; 5 to 15 μm, 8.7% to 9.6%; >15 μm, 0.23% to 1.2%. This indicates that this technology produces micron-sized basic copper sulfate, with a size significantly greater than 100 nm. Therefore, the technical solution disclosed in this paper cannot produce a strictly nanoscale basic copper sulfate suspension.

[0022] Given the current technical difficulties in preparing nanoscale particles from solid basic copper sulfate, the present invention requires a novel approach to prepare a transparent Bordeaux mixture nanosuspension smaller than 100 nm, or even smaller than 50 nm. This also demonstrates the significant technical difficulty in preparing the target product of the present invention.

[0023] [Summary of the invention]

[0024] Purpose of the present invention

[0025] One of the purposes of the present invention is to overcome the deficiencies of the prior art and provide an innovative approach and new technology that is different from the existing Bordeaux mixture preparation technology - the preparation of a transparent Bordeaux mixture nano-suspension dispersion.

[0026] Traditional Bordeaux mixture is formed by the reaction of copper sulfate and calcium hydroxide in water to form basic copper sulfate. Due to the low solubility of calcium hydroxide in water, and the even lower solubility of basic copper sulfate in water, the resulting Bordeaux mixture is a light blue, viscous, turbid suspension with large particles, let alone transparency. For ease of use, commercially, basic copper sulfate solid technical is first prepared in the factory and then processed into formulations. Since basic copper sulfate is insoluble in both water and organic solvents, current technology uses mechanical force to crush and grind it into wettable powders or small amounts of suspension formulations. The particle size of commercially available Bordeaux mixture ranges from a few to tens of microns, which increases its usage.

[0027] The innovative concept and technology of the present invention utilizes copper sulfate, one of the raw materials for preparing Bordeaux mixture, a pH buffer, a water-soluble polymer additive, and water as one component. An aqueous solution of an alkaline compound is then added as another component. Under pre-stirring, the addition method, rate, and stirring speed are controlled to ultimately produce a transparent Bordeaux mixture nanosuspension dispersion. The transparent Bordeaux mixture prepared by the present invention has particles less than 100 nm in size, a size reduction of at least two orders of magnitude compared to conventional products.

[0028] Another object of the present invention is to compound Bordeaux mixture with a highly effective, low-toxic, broad-spectrum carbamate protective organosulfur fungicide (mancozeb or propineb) in order to enhance the control effect of Bordeaux mixture and expand its fungicidal spectrum, thereby achieving a synergistic effect and reducing the dosage of a single fungicide. This method provides a Bordeaux mixture nano-suspension dispersion and a mancozeb (or propineb) nano-suspension dispersion, thereby simultaneously obtaining a Bordeaux mixture / organosulfur fungicide (mancozeb or propineb) nano-suspension dispersion.

[0029] Another object of the present invention is to shorten the processing steps for conventional Bordeaux mixture and organosulfur fungicide (mancozeb or propineb) formulations. The present invention integrates the technical synthesis and formulation processes to directly produce a Bordeaux mixture / organosulfur fungicide nanosuspension dispersion. This method eliminates the technical synthesis and purification processes and the formulation process, eliminating the corresponding production equipment. The preparation process is waste-free, environmentally friendly, and energy-efficient.

[0030] Another object of the present invention is to provide a highly effective Bordeaux mixture / organic sulfur fungicide (mancozeb or propineb) nano-suspension dispersion that can be directly used for spraying. Due to its greatly reduced particle size, its efficacy is significantly improved, contributing to reducing pesticide usage and alleviating environmental pollution.

[0031] The innovative idea of ​​the present invention

[0032] The goal of nanopesticide research is to reduce pesticide particle size, improve formulation efficacy, and reduce pesticide dosage. A common application strategy involves dissolving the active ingredient in a solvent or complex solvent to form a monomolecular dispersed solution. This solution is then processed through various methods into nanomicelles, nanocrystals, nanospheres, nanocapsules, nanogels, and various nanocarriers. However, for pesticides that are insoluble in both water and organic solvents, current technology alone cannot process them to nanoscale, let alone to sizes below 100 nm, through mechanical crushing and grinding.

[0033] The active ingredient in Bordeaux mixture is basic copper sulfate. This copper-containing inorganic compound is insoluble in both water and organic solvents. Therefore, preparing it into a transparent suspension with particle size less than 100 nm is currently a challenge in formulation research.

[0034] Organosulfur fungicides (mancozeb or propineb) contain manganese and zinc ions. Both mancozeb and propineb are insoluble in both water and organic solvents. Preparing them into transparent suspensions with particle sizes less than 100 nm remains a challenge in formulation research.

[0035] It is more difficult to compound Bordeaux mixture and mancozeb (or propineb) to prepare mixed nano-suspension dispersions. The technology of the present invention will contribute to solving these problems.

[0036] Effect of Bordeaux mixture and mancozeb

[0037] Bordeaux mixture is primarily made from a mixture of copper sulfate and slaked lime (calcium hydroxide). It is primarily used to control fungal diseases such as downy mildew and scab in fruit trees, grapes, and other crops. Its main advantages are its broad-spectrum and protective effects, as well as its relatively low environmental toxicity. Mancozeb is a compound fungicide containing three active ingredients: manganese, zinc ions, and mancozeb. This compound is effective against a wide range of plant pathogens, including various fungi and bacteria. Due to its broad spectrum and strong systemic effects, mancozeb is widely used on a variety of crops, particularly for controlling certain difficult-to-treat diseases.

[0038] Combining Bordeaux mixture with mancozeb can achieve the following effects: Enhanced broad-spectrum efficacy. Bordeaux mixture and mancozeb each have properties that prevent and control different types of diseases. Their combined use can enhance the overall disease spectrum while reducing reliance on a single pesticide, thereby alleviating pressure on the environment and delaying the development of resistance. Synergistic effect. In some cases, mixing two pesticides may produce a synergistic effect, meaning that the combined effect of the two pesticides is greater than the sum of their individual effects. Reduced risk of resistance. As a copper-containing compound, Bordeaux mixture has a fungicidal mechanism that differs from the mechanism of action of the manganese, zinc, and mancozeb in mancozeb. This mechanistic difference helps reduce the speed and probability of pathogens developing resistance to pesticides with a single mechanism of action. Using pesticides with multiple mechanisms of action can slow the development of pesticide resistance in pathogens.

[0039] The optimal ratio of Bordeaux mixture to mancozeb depends on various factors, such as region, crop type, and disease severity. The optimal ratio can generally be determined through testing. Initial trials can use a 1:1 ratio of Bordeaux mixture to mancozeb active ingredients. Based on experimental results and stability testing, the ratio can be gradually adjusted. Possible ratios include 2:1 or 1:2. A Bordeaux mixture / mancozeb water-dispersible granule formulation registered in China uses an active ingredient ratio of 1.6:1.

[0040] Effect of the combination of Bordeaux mixture and Propineb

[0041] The purposes and reasons for combining Bordeaux mixture with Propineb include: Enhanced disease control. Bordeaux mixture is primarily used to control a variety of plant diseases caused by fungi, especially downy mildew and blight. Propineb, as a broad-spectrum fungicide, is also effective against many different fungal diseases. Increased coverage. Combining them can achieve complementary effects, providing more comprehensive disease control. While each fungicide may have limitations against certain diseases when used alone, their combined use can cover a wider range of diseases, thereby improving overall control effectiveness. Bordeaux mixture and Propineb each have unique control spectra. Combining them can broaden the control spectrum, controlling diseases caused by different pathogens simultaneously and providing more comprehensive protection for farmers. Slowing the development of pesticide resistance. Combining pesticides with different mechanisms of action is an effective strategy for managing and delaying the development of resistance. Bordeaux mixture primarily works through multi-point contact killing, while Propineb may work through mechanisms such as interference with cellular metabolism. This mechanistic difference helps reduce the speed and likelihood of pathogens developing resistance to single-action pesticides.

[0042] The preparation of Bordeaux mixture and mancozeb (or propineb) into Bordeaux mixture / mancozeb and Bordeaux mixture / propineb nanosuspensions, respectively, faces enormous technical challenges. Therefore, it is necessary to consider using different preparation methods than the conventional ones.

[0043] The innovative ideas of the present invention are as follows:

[0044] The first step is to classify the raw materials for producing Bordeaux mixture and organosulfur fungicides respectively.

[0045] The raw materials for Bordeaux mixture include: copper sulfate as a precursor, alkali compounds (ammonium hydroxide, sodium hydroxide, potassium hydroxide), water-soluble polymer additives, pH buffers, and water. Copper sulfate and alkali react, so they must be separated into different components.

[0046] The raw materials for producing mancozeb include: precursor mancozeb salts, including mancozeb, sodium mancozeb, and potassium mancozeb; metal salts, including manganese salts and zinc salts. Manganese salts include manganese sulfate, manganese acetate, manganese chloride, and manganese nitrate; and zinc salts include zinc sulfate, zinc acetate, zinc chloride, and zinc nitrate.

[0047] The raw materials for producing propineb include: precursor propineb salts, including propineb ammonium, propineb sodium, and propineb potassium; the metal salts are only zinc salts, including zinc sulfate, zinc acetate, zinc chloride, and zinc nitrate.

[0048] Water-soluble polymer additives and water are common ingredients. Precursors react with manganese salts and zinc salts and must be separated into different components.

[0049] The second step is to combine the non-reactive components and divide them into different components. Take the three-component division scheme as an example:

[0050] Component A: It consists of a precursor of an organic sulfur fungicide (such as mancozeb or propinephrine), an alkaline compound (such as ammonium hydroxide), a buffer (such as ammonium sulfate) and water.

[0051] Component B: consists of metal salts, including copper sulfate, manganese salts, zinc salts, or their aqueous solutions.

[0052] Component C: consists of one or more water-soluble polymer additives or their aqueous solutions.

[0053] To simplify the components, it can be further divided into a two-component solution. It can be considered that component A in the two-component solution is equivalent to "component A + component C" in the three-component solution.

[0054] The third step is to utilize the water dilution process of the pesticide formulation before use to proportionally distribute the dilution water, and dilute component A and component B in the above two-component solution into the distributed proportional water to obtain the corresponding dilution solution.

[0055] The fourth step is to control different addition methods and speeds, stirring methods and speeds under pre-stirring to keep the basic copper sulfate particles and mancozeb (or propineb) particles generated in the system at the nanometer scale, thereby obtaining a transparent Bordeaux mixture / mancozeb (or propineb) nano-suspension dispersion.

[0056] To achieve this goal, the following points must be focused on:

[0057] (1) Controlling the reaction rate of basic copper sulfate, mancozeb (or propineb) molecules, the rate of crystal nucleation, and the rate of crystal growth is the key to obtaining particles less than 100nm in size. This involves the selection of reaction components and dosages, the type and dosage of water-soluble polymer additives, the amount of water used, the control of pH and the choice of buffer, as well as consideration of factors such as the dispersion and stability of the generated nanoparticles.

[0058] (2) The strength and selection of alkaline compounds. The alkali used in traditional Bordeaux mixture is slaked lime, that is, calcium hydroxide. Its alkalinity is relatively weak, so the reaction rate with copper sulfate is slow and easy to control, but its water solubility is poor (solubility is about 0.165 grams per 100 grams of water). When the concentration is high, the particles are large, making it difficult to separate the generated basic copper sulfate with even poorer water solubility, and the system eventually forms a viscous suspension with larger particle size. In addition to calcium hydroxide, alkaline compounds that can also be used include sodium hydroxide, potassium hydroxide, and ammonium hydroxide, which have greater solubility. The first two are strong bases and react quickly with copper sulfate. The alkalinity of ammonium hydroxide is relatively weak, and its reaction rate with copper sulfate is lower than the first two, and the rate of generating basic copper sulfate is relatively slow. Considering the control of the generation rate of basic copper sulfate, the nucleation and crystallization of particles, and the growth rate, ammonium hydroxide is preferred as the alkaline compound.

[0059] (3) Selection of precursors for the organosulfur fungicide (mancozeb or propineb). Precursors for both include mancozeb and propineb, which are available in ammonium, sodium, and potassium salts, respectively. Ammonium salts are preferred in this invention because they are weak bases and less reactive with manganese and zinc salts than sodium and potassium salts. These salts are monomolecularly dispersed in water, and when they interact, mancozeb or propineb molecules readily form. By initiating stirring before mixing and controlling reaction conditions, nanocrystals of the organosulfur fungicide can also be generated simultaneously.

[0060] (4) Selection of the type and dosage of water-soluble polymer additives. Whether copper sulfate reacts with an alkaline compound to form basic copper sulfate, or the precursor mancozeb (or propineb) reacts with a manganese salt or zinc salt (or only a zinc salt) to form mancozeb (or propineb), the products are insoluble in water and will inevitably aggregate in water, forming crystal nuclei. These nuclei continue to grow and eventually precipitate from the water. The objective of the present invention is to control the crystal size of the generated basic copper sulfate and mancozeb (or propineb) to no more than 100 nm. To prevent further growth of the crystal nuclei formed in water and to disperse, suspend, and stabilize them, a water-soluble polymer additive must be added to the system. Water-soluble polymer additives contain 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, thus providing a suspending effect. The high viscosity of water-soluble polymer solutions is due to the different morphological structure of water-soluble polymers in water compared to small molecules. Due to their large molecular weight and long molecular chains, polymers dissolve in water not as straight chains but rather as random coils. These random coils, dispersed in water as dissolved molecules, can range in size from a few nanometers to tens or even hundreds of nanometers, depending primarily on their relative molecular mass and the flexibility of their molecular chains. These random coils suspend nanocrystals generated in solution. This is due to their loose spatial structure. Under stirring, the small basic copper sulfate and mancozeb (or propineb) crystals generated by the reaction are attracted to these coils, thereby preventing them from agglomerating and dispersing, suspending, and stabilizing the particles, preventing and controlling their further growth.

[0061] 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 additives can be determined through experimentation.

[0062] 5. Select the dilution water volume. The amount of dilution water actually determines the concentration of basic copper sulfate and mancozeb (or propineb) nanoparticles generated in the system. Theoretically, a lower dilution water volume results in a higher concentration of nanoparticles, a greater tendency for collisions, aggregation, and growth, and an unstable system with the risk of precipitation. Conversely, a higher dilution water volume, as long as the amount of polymer additive is sufficient, will easily form a transparent and stable Bordeaux mixture / mancozeb (or propineb) nanosuspension dispersion.

[0063] Explanation of terms

[0064] 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).

[0065] 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.

[0066] 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.

[0067] System: The so-called system refers to the system in which, during the preparation of a transparent basic copper sulfate and mancozeb (or propineb) suspension dispersion, the base reacts with the copper sulfate, and the manganese salt and zinc salt react with the precursor, while controlling the addition method, speed, and stirring speed. The system is composed of copper sulfate, the base compound, the precursor, the manganese salt, the zinc salt, a polymer additive, and water.

[0068] 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.

[0069] Ingredients: The so-called ingredients refer to the raw materials used in the present invention, including water-soluble precursors, copper sulfate, alkali compounds, manganese salts, zinc salts, water-soluble polymer additives, buffers and water.

[0070] Water-soluble polymer additives are water-soluble polymer compounds containing hydrophilic groups or hydrophobic backbones within their macromolecules. They are also known as water-soluble polymer surfactants or polymer additives. Water-soluble polymer additives can provide dispersion, suspension, emulsification, and stabilization. Based on the nature of the groups, they can be categorized as anionic, cationic, zwitterionic, and nonionic polymer additives.

[0071] Particle size: also known as particle size, mainly refers to the size of basic copper sulfate, mancozeb (or propineb) particles generated in the system. This particle is usually a crystalline grain and does not specifically refer to the microscopic morphological structure of the grain.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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 be at or close to the effective stirring speed.

[0076] 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.

[0077] Addition speed: After determining the addition method, control the amount of components added with the goal of achieving effective stirring.

[0078] The key technologies of the present invention lie in the following aspects:

[0079] 1. Reaction to generate basic copper sulfate nanoparticles

[0080] Copper sulfate (CuSO4) reacts with sodium hydroxide (NaOH), potassium hydroxide (KOH), and ammonium hydroxide (NH4OH) to produce basic copper sulfate. Based on the difficulty of implementation and reaction conditions, the reactions are divided into the following two categories:

[0081] ⑴Reaction with NaOH or KOH:

[0082] CuSO4 reacts the same way with NaOH or KOH. They can produce either copper hydroxide or basic copper sulfate, depending on the molar ratio of the reactants. Taking potassium hydroxide as an example, the reaction equations are as follows: CuSO4 + 2KOH → Cu(OH)2↓ + K2SO4 2CuSO4 + 2KOH → Cu2(OH)2SO4↓ + K2SO4

[0083] The key difference between producing copper hydroxide and basic copper sulfate lies in the amount of base used. Two base molecules react with one copper sulfate molecule to produce a precipitate of copper hydroxide (Cu(OH)2). To form basic copper sulfate, the amount of base must be controlled—reduced to prevent complete neutralization of all copper ions in the copper sulfate, allowing some copper ions to form as basic copper sulfate. The ideal amount of base depends on the desired chemical formula for basic copper sulfate, specifically the ratio of copper sulfate to base molecules.

[0084] The reaction of NaOH or KOH with CuSO₄ to form basic copper sulfate is easy to achieve, typically at room temperature and under mild reaction conditions. Because strong bases are highly soluble in water, they react rapidly with copper sulfate to form a basic copper sulfate precipitate. However, a fast reaction speed is not a favorable factor for controlling the size of the resulting nanocrystals.

[0085] ⑵Reaction with NH4OH:

[0086] CuSO4 reacts with NH4OH to generate basic copper sulfate according to a reaction formula similar to that of potassium hydroxide. For example: 2CuSO4+2NH4OH→Cu2(OH)2SO4↓+(NH4)2SO4

[0087] The exact chemical composition of basic copper sulfate may vary depending on the reaction conditions and the ratio of the reactants. For example, another reaction is: 3CuSO4+6NH4OH→Cu3(OH)4(SO4)2↓+2(NH4)2SO4+2H2O

[0088] This reaction represents the reaction of three copper sulfate molecules with six ammonium hydroxide molecules to produce one basic copper sulfate molecule, two ammonium sulfate molecules, and water. This reaction equation is based on a specific form of basic copper sulfate; the actual product composition may vary depending on experimental conditions (e.g., reactant concentrations, solution pH, temperature, etc.).

[0089] NH4OH reacts with CuSO4 to form basic copper sulfate, but the process is more complex than with NaOH or KOH because ammonia (NH4OH) is a weak base and has a relatively weak ability to form basic copper sulfate, requiring a slightly longer reaction time or a larger amount of base. However, the fact that NH4OH is a weak base allows for milder reaction conditions, which is beneficial for controlling the formation of nanoparticles.

[0090] ⑶Comparison of the two reactions

[0091] NaOH and KOH are strong bases that react quickly and efficiently with CuSO4, while NH4OH is a weak base with a slower reaction rate. The former is advantageous for reactions aimed at obtaining solid precipitation of basic copper sulfate, but the latter is undoubtedly more controllable for obtaining nanoscale suspensions of basic copper sulfate.

[0092] Considering that the object of the present invention is to prepare basic copper sulfate nano suspension dispersion liquid, preferred reaction rate is slower, slows down the NH OH scheme that precipitation forms.This scheme easily controls the growth rate of crystal grain, helps to form the more uniform nanoparticle of size and prevents precipitation from producing.In order to further slow down the generation rate of basic copper sulfate crystal grain, avoid the fast growth and aggregation of crystal grain, can add the material of regulating pH value in system, to reduce the pH value of the local area that alkali (for example ammoniacal liquor) forms when adding system.Add the material of a kind of strong acid and weak base salt as buffer, for example ammonium chloride, ammonium sulfate.

[0093] The preferred raw materials of the present invention are copper sulfate and ammonia water, and the preferred molecular ratio of copper sulfate to ammonia water is 1:1.

[0094] 2. Ratio of components for the reaction to generate mancozeb (or propineb)

[0095] Target of the present invention is to prepare Bordeaux mixture / mancozeb (or propineb) nano suspension dispersion liquid.When generating basic copper sulfate nano-crystal grains, system also generates mancozeb (or propineb) nano-crystal grains simultaneously.Their precursor is mancozeb (or propineb), by reacting with manganese salt, zinc salt (or being only zinc salt) of appropriate proportion, mancozeb (or propineb) product is easy to generate in the system.Same problem is, how to control the speed that generation mancozeb (or propineb) generates, and the growth rate of crystal grain, also is the key technology that obtains composite nano suspension dispersion liquid.

[0096] When mancozeb is selected as the precursor of mancozeb, and manganese sulfate and zinc sulfate are selected as the manganese salt and zinc salt, the mass ratio range is:

[0097] Mancozeb (producing 100 mass%): manganese sulfate: zinc sulfate = 90: 41-55: 7-17

[0098] Preferably, mancozeb: manganese sulfate: zinc sulfate = 90: 41-43: 7-9

[0099] Furthermore, mancozeb: manganese sulfate: zinc sulfate = 90:41:7

[0100] When choosing propineb as the precursor of propineb and zinc sulfate as the zinc salt, since propineb has two ammonium acid groups and zinc ion is a divalent metal ion, the molecular ratio of the two should be 1:1.

[0101] Propinenium (generating 100 mass of Propineb): Zinc sulfate = 90:56.

[0102] 3. Preparation conditions of basic copper sulfate / mancozeb (or propineb) nanosuspension dispersion

[0103] Nanoscale basic copper sulfate is prepared by reacting a copper sulfate solution with an NH₄OH solution. Mancozeb (or propineb) is prepared by reacting mancozeb (or propineb) with a manganese salt and a zinc salt (or just a zinc salt). Key control factors include ingredient selection, component design, reactant concentration, addition method, stirring speed, and other reaction conditions.

[0104] After determining the ingredients and component plan, controlling reaction conditions is a crucial factor. Under pre-stirring conditions, the method and speed of adding one diluent to the other, as well as the stirring method and speed, are crucial for controlling the rate of product formation and crystallite size. Slow addition and thorough stirring are key to successfully obtaining Bordeaux mixture / mancozeb (or propineb) nanosuspension dispersions. Secondly, the selection and dosage of water-soluble polymer additives, as well as the dilution water consumption, are also crucial for achieving a stable nanosuspension dispersion.

[0105] 4. Selection of water-soluble polymer additives (polymer dispersants)

[0106] When preparing nano-sized basic copper sulfate / mancozeb (or propineb) nano-suspension dispersions, it is also crucial to select appropriate water-soluble polymer additives as dispersants to prevent precipitation and maintain transparency. These substances can help stabilize the nanoparticles, prevent their aggregation and precipitation, and thus maintain the transparency of the solution. The water-soluble polymer additives selected in the present invention include:

[0107] Polyvinyl pyrrolidone (PVP) and polyvinyl alcohol (PVA) are commonly used water-soluble synthetic polymers that are used as dispersants and suspending agents to effectively stabilize various nanoparticles and prevent their aggregation. Both can form a stable protective layer on the surface of nanoparticles by adsorption, preventing aggregation between particles.

[0108] (2) Alkyl ether sulfate (sodium salt, ammonium salt) is a nonionic anionic surfactant widely used to stabilize nanoparticles. The lipophilic groups in the molecule can adsorb on the surface of nanoparticles, while the hydrophilic groups extend into the solution, enhancing the dispersion of the particles in water.

[0109] (3) Sodium carboxymethyl cellulose (CMC), a water-soluble cellulose derivative with a small amount of anionic groups, can effectively increase the viscosity of aqueous solutions. It improves dispersibility by forming a stable layer on the surface of nanoparticles and can be used as an effective dispersant for stabilizing various nanoparticles.

[0110] (4) Polyoxyethylene ether and its derivatives are a type of nonionic surfactant. Polyoxyethylene ether is a hydrophilic group, while the lipophilic group can be an alkyl fatty chain, alkylphenol group, arylaryl group, alkylaryl group, oil group, etc. It can form micelles and random coils with hydrophilic groups on the outside and lipophilic groups on the inside, so that nanoparticles can be dispersed in them to achieve stability.

[0111] ⑸Other anionic and nonionic polymer surfactants.

[0112] It should be noted that alkyl ether sulfates (sodium or ammonium salts) and sodium carboxymethyl cellulose are both anionic surfactants with nonionic properties, meaning that their molecules contain moieties that can dissociate into negative charges in water. When these anionic surfactants encounter copper, manganese, and zinc ions, they may form some form of complex. However, whether these potential products are soluble in water depends on the specific conditions and reaction ratio. However, if the concentration of these additives is high enough and their hydrophilic groups provide sufficient water solubility, such complexes may also maintain a certain degree of water solubility. Sodium carboxymethyl cellulose is a polymeric dispersant, and its interaction with copper ions may lead to the formation of complexes between or within molecular chains. In this case, the water solubility of the complex depends primarily on its molecular weight, degree of substitution, and other conditions in the solution. In some cases, it can act as a stabilizer to help copper ions remain dispersed in aqueous solutions.

[0113] In summary, when using these polymeric additives as dispersants, it is important to determine the most appropriate concentration and conditions 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, naturally biodegradable polymeric additives or their derivatives are preferred. Furthermore, in some cases, a combination of different dispersants, known as composite additives, may be necessary to achieve optimal results.

[0114] 5. The appropriate pH range is conducive to the stable dispersion of nanoparticles

[0115] The stable dispersion of nanoparticles in aqueous solutions is influenced by various factors, including the solution's pH. For example, the formation and stability of basic copper sulfate nanoparticles are affected by pH. To enhance nanoparticle stability, the pH should be adjusted to a range that maximizes the surface charge of the nanoparticles, which helps prevent aggregation through electrostatic repulsion.

[0116] Different types of nanoparticles have different pH ranges. For example, metal oxide nanoparticles (such as TiO2 and ZnO) are more stable at pH values ​​far from their isoelectric point (IEP), the pH at which the particle surface charge reaches zero. For example, the IEP of TiO2 is approximately pH 6.5, so nanoparticles are generally more stable in environments with a pH < 5 or pH > 8. Silver nanoparticles (Ag) generally exhibit good stability in slightly acidic to neutral environments (approximately pH 5.5 to 7) because within this pH range, the surface may have sufficient negative charge to promote electrostatic repulsion between particles. For basic copper sulfate nanoparticles, the ideal pH range may be from weakly acidic to weakly alkaline (approximately pH 6 to 7.5). This range is conducive to nanoparticle stability. Substances added to maintain a stable pH in the system are called buffers. For alkaline substances like basic copper sulfate, buffers are typically strong acid and weak base salts, such as ammonium chloride and ammonium sulfate.

[0117] 6. The amount of dilution water is another key factor in obtaining a stable nanosuspension dispersion

[0118] To ensure the transparency and stability of nanoparticle suspensions of basic copper sulfate / mancozeb (or propineb), in addition to the aforementioned factors, the dilution water consumption is also a key factor that needs to be controlled. High concentrations of basic copper sulfate and mancozeb (or propineb) are detrimental to the dispersion and stability of nanoparticles. Collisions between particles lead to merging, growth, and ultimately precipitation. Therefore, for nanoparticle dispersions of a certain concentration prepared under certain conditions, there should be a relationship between the time span for maintaining stable solution transparency and the amount of dilution water used. Clarifying this relationship requires experimental confirmation.

[0119] The basic copper sulfate / mancozeb nano-suspension dispersion obtained by the present invention is used to prevent and control downy mildew and white rot of grapes. An example shows that the required active ingredients are 36-60 / 22.5-37.5 g / mu respectively, and the dilution water amount is 45-75 kg, that is, the concentrations of basic copper sulfate and mancozeb should generally be no more than 0.08% and 0.05%.

[0120] 7. Morphological structure of metal ions in nanodispersions

[0121] In Bordeaux mixture / mancozeb (or propineb) nano-suspension dispersion, metal ions, including copper ions (Cu 2+ ), manganese ions (Mn 2+ ), zinc ions (Zn 2+ ) in the system may be complex and affected by many factors, including the chemical properties of the ions themselves, the pH value of the system, and other chemical substances present.

[0122] These three ions are all multivalent metal ions. In the system, they exist in three forms: free ions, complexes and precipitations. Copper in Bordeaux mixture is mainly in the form of Cu 2+ Manganese exists in the form of Mn under neutral or slightly acidic pH conditions, and zinc exists in the form of Mn under most pH conditions. 2+ 、Zn 2+ They exist in the form of free ions. When organic acids are present in the system, copper, manganese, and zinc ions can form stable complexes. Mancozeb (or propineb) precursors, such as mancozeb (or propineb), dissociate into negatively charged groups in water, so in principle, all three metal ions can form complexes with them. Under higher pH conditions, copper, manganese, and zinc can form Cu(OH)2, Mn(OH)2, and Zn(OH)2 precipitates. Since the pH value of the system is controlled within the range of 6.5 to 7.5, this situation does not occur. Therefore, the system only exists in the form of free ions and complexes.

[0123] When used in combination, ions can interact, and different metal ions may compete or influence each other, such as in ion exchange or precipitation reactions. However, regardless of the morphological structure of the three metal ions in the nanosuspension dispersion, after spraying on crops, these nanoparticles are composed of the precursors to the target product and the metal ions, and these chemical components can play a comprehensive role in disease prevention and control. Because their particle size has been reduced to below 100nm, the dramatically increased number of particles will achieve more effective disease prevention and control.

[0124] Characteristics of Transparent Bordeaux Mixture / Mancozeb (or Propineb) Nanosuspension Dispersion

[0125] The transparent Bordeaux mixture / mancozeb (or propineb) nano-suspension dispersion is a mixture of basic copper sulfate and mancozeb (or propineb) nano-particles suspended and dispersed in a random coil morphology structure formed by dissolving a water-soluble polymer dispersant in water.

[0126] The basic copper sulfate is produced by reacting copper sulfate with an alkali compound in the presence of a buffer under certain conditions. The alkali compound is ammonium hydroxide, sodium hydroxide, or potassium hydroxide, preferably ammonium hydroxide; and the buffer is a salt of a strong acid and a weak base, preferably ammonium sulfate or ammonium chloride.

[0127] The mancozeb is produced by reacting a mancozeb precursor with a manganese salt and a zinc salt under certain conditions. The mancozeb is mancozeb, mancozeb sodium, or mancozeb potassium, preferably mancozeb; the manganese salt is manganese sulfate, manganese acetate, manganese chloride, or manganese nitrate, preferably manganese sulfate; and the zinc salt is zinc sulfate, zinc acetate, zinc chloride, or zinc nitrate, preferably zinc sulfate.

[0128] The propineb is produced by reacting a propineb salt precursor with a zinc salt under certain conditions. The propineb salt is propineb ammonium, propineb sodium, or propineb potassium, preferably propineb ammonium; and the zinc salt is zinc sulfate, zinc acetate, zinc chloride, or zinc nitrate, preferably zinc sulfate.

[0129] The particle size of the Bordeaux mixture / mancozeb (or propineb) nano-suspension dispersion is below 100 nanometers.

[0130] The water-soluble polymer dispersant in the form of a random coil structure can suspend, disperse and stabilize basic copper sulfate and mancozeb (or propineb) crystals.

[0131] The water-soluble polymer dispersant in the form of a random coil structure is at least one of the following:

[0132] Polyvinyl pyrrolidone, polyvinyl alcohol, alkyl ether sulfate, sodium carboxymethyl cellulose, polyoxyethylene ether and its derivatives, etc.

[0133] The transparent Bordeaux mixture / mancozeb (or propineb) nano-suspension dispersion liquid uses pure water as a solvent.

[0134] The pH range of the transparent Bordeaux mixture nanosuspension is from weakly acidic to weakly alkaline.

[0135] The pH value range of the transparent Bordeaux mixture nanosuspension is 5.5-8.

[0136] The preferred pH range is 6 to 7.5.

[0137] Preparation method of transparent Bordeaux mixture / mancozeb (or propineb) nano-suspension dispersion

[0138] The present invention adopts the following technical solutions:

[0139] Preparation method of transparent Bordeaux mixture / mancozeb (or propineb) nano-suspension dispersion

[0140] Three-component solution: This includes the following steps:

[0141] ⑴ Distribution and preparation of ingredients in components

[0142] Component A: consists of mancozeb (or propinephrine), a precursor of an organosulfur fungicide, an alkali compound (such as ammonium hydroxide), a buffer (such as ammonium sulfate), and water. These ingredients are added to water and stirred to dissolve to obtain a transparent aqueous solution of component A.

[0143] Component B: For Bordeaux mixture / mancozeb combinations, it consists of solid or aqueous solutions of metal salts, including copper sulfate, manganese salts (such as manganese sulfate), and zinc salts (such as zinc sulfate). For Bordeaux mixture / propineb combinations, it consists of solid or aqueous solutions of metal salts, including copper sulfate and zinc salts (such as zinc sulfate). Component B is a solid mixture of metal salts or a mixed aqueous solution of metal salts dissolved in water. The packaging method should be based on ease of packaging, transportation, and use.

[0144] Component C: consists of one or more water-soluble polymer additives or their aqueous solutions.

[0145] ⑵ Dilution of components

[0146] Divide the dilution water into two parts according to the proportion. Considering that the amount of metal salt accounts for a small proportion of the total components, the distribution principle is that the dilution water amount of component B as the added component should be much smaller than the dilution water amount of the added component.

[0147] The first step is to dilute and dissolve high molecular weight additives, considering that they are more difficult to dissolve than small molecules. Therefore, first add component C to the dilution water in the appropriate proportion and stir to dissolve. Then add component A and stir to dissolve to obtain a transparent mixed diluted aqueous solution of "component A + component C".

[0148] The second step is to dissolve component B into the dilution water in the distribution ratio to obtain a transparent diluted aqueous solution of component B.

[0149] ⑶ The two components undergo mixed reaction

[0150] At room temperature and under pre-stirring, add the diluted aqueous solution of component B into the transparent mixed diluted aqueous solution of "component A + component C" according to a certain adding method and stirring method.

[0151] Control the addition rate and stirring speed to ensure uniform dispersion and keep the system transparent until component B is added. A transparent Bordeaux mixture / mancozeb (or propineb) nanosuspension dispersion is obtained with a pH range of 6 to 7.5.

[0152] Two-component solution:

[0153] The preparation method is simpler than the three-component solution. Component A in the two-component solution can be considered equivalent to "Component A + Component C" in the three-component solution. Other dilution and mixing steps are the same.

[0154]

Brief description of the attached drawings

[0155] Figure 1: Flowchart for preparing Bordeaux mixture / mancozeb nanosuspension dispersion (two components)

[0156] Figure 2: Flowchart for preparing Bordeaux mixture / mancozeb nanosuspension dispersion (three components)

[0157] Figure 3: Flowchart for preparing Bordeaux mixture / Propineb nanosuspension dispersion (two components)

[0158] Figure 4: Flowchart for preparing Bordeaux mixture / Propineb nanosuspension dispersion (three components)

[0159] [Implementation Method]

[0160] Example 1.

[0161] Bordeaux mixture / mancozeb nanopesticide suspension can be used to control downy mildew and white rot in grapes. A practical example shows that the required active ingredients are 36-60 g / mu and 22.5-37.5 g / mu, respectively, and the dilution water requirement is 45-75 kg. Considering the high efficiency of nanopesticides, this example uses a Bordeaux mixture / mancozeb active ingredient dosage of 36 g / mu and 22 g / mu, respectively. The dilution water requirement is 45 kg.

[0162] According to the following molecular ratio of chemical reaction formula:

[0163] The dosage of each component, the distribution ratio of dilution water, and the preparation method of the solution are listed in the following table:

[0164] How to do it:

[0165] (1) In an appropriate container, add water in a distribution ratio of 8 / 9 (40 kg), add component C, stir and dissolve to obtain a transparent diluted aqueous solution of component C.

[0166] ⑵ Add component A to the diluted aqueous solution of component C, stir and dissolve to obtain a transparent diluted aqueous solution of "component A + component C".

[0167] ⑶ In another appropriate container, add water in a distribution ratio of 1 / 9 (5 kg), add component B, stir and dissolve to obtain a transparent diluted aqueous solution of component B.

[0168] (4) While pre-stirring, add the diluted aqueous solution of component B to the diluted aqueous solution of "component A + component C" by intermittent spraying. Control the addition speed and stirring speed to ensure uniform dispersion and keep the system transparent until component B is completely added.

[0169] The obtained transparent Bordeaux mixture / mancozeb nano-suspension dispersion can be directly used for spraying grapes. The stability time of the Bordeaux mixture / mancozeb nano-suspension dispersion was observed to be 4 hours.

[0170] Example 2.

[0171] Bordeaux mixture / Propineb nanoparticle suspension dispersion can be used to control leaf spot and ring rot in apple trees. Traditional Bordeaux mixture and Propineb wettable powder formulations require active ingredient concentrations of 140 and 100 grams per mu, respectively. Considering the high efficacy of nanopesticides, this example uses Bordeaux mixture / Propineb at a ratio of 60 and 20 grams per mu, respectively, for a 3:1 ratio. The dilution water requirement is 150 kilograms per mu.

[0172] This embodiment is based on the following chemical reaction formula:

[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] (1) In a suitable container, add water in a distribution ratio of 14 / 15 (140 kg), add component A, stir and dissolve to obtain a transparent diluted aqueous solution of component A.

[0176] ⑵In 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.

[0177] ⑶ Under pre-stirring, add the diluted solution of component B to the diluted aqueous solution of component A in a continuous spraying manner, controlling the addition speed and stirring speed to keep the system always transparent until the addition of component B is completed.

[0178] A transparent Bordeaux mixture / Propineb nano-suspension dispersion was obtained, which can be directly used for spraying apple trees. The stability time of the Bordeaux mixture / Propineb nano-suspension dispersion was observed and found to be 5 hours.

Claims

1. A Bordeaux mixture / mancozeb nano-suspension dispersion, wherein the Bordeaux mixture / mancozeb nano-suspension dispersion is a Bordeaux mixture / mancozeb nano-suspension dispersion of less than 100 nanometers, and is generated by a mixed reaction of three components: Component A: It is composed of an aqueous solution of an alkali compound, mancozeb and a buffer; Component B: composed of copper sulfate, manganese salt, zinc salt solid or their aqueous solution; Component C: composed of at least one water-soluble polymer dispersant, or its aqueous solution; Under the conditions of pre-stirring and effective stirring, the generated basic copper sulfate and mancozeb particles are dispersed in a random coil morphology structure formed by the water-soluble polymer dispersant dissolved in water.

2. Bordeaux mixture / mancozeb nano suspension dispersion according to claim 1, characterized in that, The water-soluble polymer dispersant is at least one of the following options: Polyvinyl pyrrolidone; polyvinyl alcohol; alkyl sulfates and their derivatives; sodium carboxymethyl cellulose; polyoxyethylene ether and its derivatives.

3. The Bordeaux mixture / mancozeb nano suspension dispersion according to claim 1, characterized in that: When manganese sulfate and zinc sulfate are selected as manganese salt and zinc salt, the mass ratio of mancozeb: manganese sulfate: zinc sulfate is in the range of: Mancozeb: manganese sulfate: zinc sulfate = 90:41-55:7-17; Preferably, mancozeb:manganese sulfate:zinc sulfate=90:41:

7.

4. The Bordeaux mixture / mancozeb nano suspension dispersion according to claim 1, characterized in that: The pH range of the Bordeaux mixture / mancozeb nano suspension dispersion is from weak acid to weak alkalinity.

5. The Bordeaux mixture / mancozeb nano suspension dispersion according to claim 4, characterized in that: The pH range is 6 to 7.

5.

6. A Bordeaux mixture / propineb nano-suspension dispersion, wherein the Bordeaux mixture / propineb nano-suspension dispersion is a Bordeaux mixture / propineb nano-suspension dispersion of less than 100 nanometers, and is generated by a mixed reaction of three components: Component A: It is composed of an aqueous solution of a base compound, propionate, and a buffer; Component B: composed of copper sulfate, zinc salt solid or its aqueous solution; Component C: composed of at least one water-soluble polymer dispersant, or its aqueous solution; Under the conditions of pre-stirring and effective stirring, the generated basic copper sulfate and propineb particles are dispersed in the random coil morphology structure formed by the water-soluble polymer dispersant dissolved in water.

7. The Bordeaux mixture / Propineb nanosuspension dispersion according to claim 6, characterized in that: The water-soluble polymer dispersant is at least one of the following options: Polyvinyl pyrrolidone; polyvinyl alcohol; alkyl sulfates and their derivatives; sodium carboxymethyl cellulose; polyoxyethylene ether and its derivatives.

8. The Bordeaux mixture / Propineb nano suspension dispersion according to claim 6, characterized in that: When zinc sulfate is selected as the zinc salt, the mass ratio of propionate: zinc sulfate is: Propanol: zinc sulfate = 90:

56.

9. The Bordeaux mixture / Propineb nano suspension dispersion according to claim 6, characterized in that: The pH range of the Bordeaux mixture / mancozeb nano suspension dispersion is from weak acid to weak alkalinity.

10. The Bordeaux mixture / Propineb nanosuspension dispersion according to claim 9, characterized in that: The pH range is 6 to 7.

5.

11. A method for preparing a Bordeaux mixture / mancozeb nano-suspension dispersion, comprising the following steps: 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 Bordeaux mixture / 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 Bordeaux mixture / mancozeb nano-suspension dispersion; Component A: an aqueous solution consisting of an alkali compound, mancozeb, a water-soluble polymer dispersant and water; Component B: solid copper sulfate, manganese salt and zinc salt or aqueous copper sulfate, manganese salt and zinc salt solution; The generated basic copper sulfate and mancozeb particles are dispersed in a random coil morphology structure formed by the water-soluble polymer dispersant dissolved in water.

12. A method for preparing a Bordeaux mixture / propineb nano-suspension dispersion, comprising the following steps: 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 Bordeaux mixture / propineb 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 Bordeaux mixture / propineb nano-suspension dispersion; Component A: an aqueous solution consisting of an alkali compound, propinephrine, a water-soluble polymer dispersant and water; Component B: copper sulfate, zinc salt solid or copper sulfate, zinc salt aqueous solution; The generated basic copper sulfate and propineb particles are dispersed in a random coil morphology structure formed by the water-soluble polymer dispersant dissolved in water.

13. The preparation method according to claim 11 or 12, further comprising the steps of: 1) Check the pH of the product Bordeaux mixture / mancozeb nano-suspension dispersion or Bordeaux mixture / propineb nano-suspension dispersion value, adjust it to weak acidity to weak alkalinity.

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