NANO suspension dispersion liquid of copper oxychloride / kasugamycin
Through solution reaction control conditions, Wang Tong nano-suspended dispersion was obtained directly and combined with lenticularin, which solved the low efficacy and environmental protection problems caused by the large particle size of traditional Wang Tong preparations, and achieved nano-scale preparations with particle size less than 100nm, improving the efficacy and environmental protection performance.
Patent Information
- Application Number
- PCT/CN2024/129528
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-05-15
- Filing Date
- 2024-11-02
- Publication Date
- 2025-05-08
AI Technical Summary
The particles of existing Wang Tong preparations are large in size, resulting in low efficacy, large dosage, and many residues. It is difficult for traditional processing technology to achieve nano-scale particles, limiting their application of improving drug efficacy and environmental protection and energy-saving.
By reacting with a solution of copper chloride and a water-soluble alkali, the reaction conditions were controlled, and the nanosuspended dispersion of Wang copper was obtained directly, and combined with lenticularin to prepare a Wang copper/Chun Raythromycin nanosuspended dispersion with a particle size of less than 100 nm.
It significantly reduces the particle size, improves the efficacy of medicine, reduces the amount of pesticides, reduces the impact on the environment, achieves the goal of environmental protection and energy saving, and simplifies the production process, and removes the synthesis and preparation processing technology of the original drug.
Smart Images

Figure CN2024129528_08052025_PF_FP_ABST
Abstract
Description
Copper oxychloride / Kasugamycin nanosuspension dispersion
Technical field
[0001] The invention belongs to the field of nano pesticides, and particularly relates to the preparation of a suspension dispersion in which an inorganic copper compound insoluble in water and solvent is compounded with a kasugamycin fungicide and the particle size of the suspension dispersion 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 or basic copper chloride, is a light green powder and an inorganic copper compound that can have a variety of structures. The active ingredient of copper oxychloride is copper oxychloride, and its general chemical formula is: CuCl2·3Cu(OH)2
[0006] 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.
[0007] 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.
[0008] 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 kasugamycin, 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.
[0009] 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.
[0010] [Summary of the invention]
[0011] Purpose of the present invention
[0012] One of the purposes of the present invention is to overcome the shortcomings of the existing technology and provide an innovative approach and technology that is different from the existing copper oxychloride preparation technology - the preparation of copper oxychloride nano-suspension dispersion. 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 concept and technical approach of this invention utilizes the pesticide dilution process, using copper chloride and a water-soluble base in two separate components to directly produce a copper oxychloride nanosuspension dispersion through a solution reaction under controlled reaction conditions.
[0013] Another object of the present invention is to compound copper oxychloride with kasugamycin, an agricultural antibiotic fungicide, to improve the control effect of copper oxychloride and expand its bactericidal spectrum, so as to have a synergistic effect and reduce the dosage of a single variety, thereby obtaining a copper oxychloride nanosuspension dispersion and a kasugamycin aqueous solution, that is, simultaneously obtaining a copper oxychloride / kasugamycin nanosuspension dispersion.
[0014] Another object of the present invention is to reduce the particle size of copper oxychloride / kasugamycin. 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 efficacy. The copper oxychloride / kasugamycin nanosuspension dispersion prepared by the present invention has a particle size of less than 100 nm, significantly reducing the particle size and thus significantly improving the efficacy of copper oxychloride / kasugamycin combination formulations.
[0015] Another object of the present invention is to eliminate the copper oxychloride technical synthesis and formulation processing process. Commercially, the copper oxychloride technical is first prepared by the technical manufacturer, and then the copper oxychloride / kasugamycin compound formulation is processed in the formulation factory. The present invention directly uses the raw materials for synthesizing copper oxychloride and kasugamycin, utilizes the pesticide dilution process with water, and controls the reaction conditions to obtain a transparent copper oxychloride / kasugamycin nanosuspension dispersion. This method eliminates the copper oxychloride synthesis and formulation processing process, directly eliminates the technical synthesis and purification process, formulation processing technology, and corresponding production equipment, and the process does not generate wastewater, is environmentally friendly and energy-saving, and has significant effects.
[0016] Another object of the present invention is to provide a copper oxychloride / kasugamycin nanosuspension dispersion that can be directly sprayed. The dispersion is prepared to a suitable spraying concentration for crops based on the dilution water and the amount of product generated, and spraying can be performed directly after preparation. Because the pesticide particles are less than 100 nm in size, their efficacy can be significantly improved, pesticide usage can be reduced, and this contributes to sustainable agricultural development.
[0017] The innovative idea of the present invention
[0018] Copper oxychloride and kasugamycin have their own unique performance characteristics
[0019] Copper Oxide has a wide range of fungicidal effects. It is effective in preventing and treating a variety of fungal and bacterial diseases, such as canker, bacterial leaf spot, yellow spot, snake eye disease, wilt, scab, sooty mold, anthracnose, and angular leaf spot. It is particularly effective in preventing and treating bacterial diseases and can effectively address crop diseases caused by bacterial infection. It has good compatibility. It can be mixed with many fungicides and insecticides to expand the scope of prevention and control and improve the prevention and control effect. It is resistant to rain erosion. When sprayed on the surface of crops, a film will be formed. This film not only prevents the invasion of pathogens, but also has good resistance to rain erosion. Even after rain, the agent can still maintain a good prevention and control effect, reducing the problem of reduced efficacy caused by rain erosion.
[0020] Relatively safe. Among copper preparations, Copper Royal is relatively safe for crops. When used correctly, it is not likely to cause phytotoxicity. It is suitable for a variety of crops, such as citrus, lychees, grapes, tomatoes, and cucumbers.
[0021] 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.
[0022] Kasugamycin, whose chemical name is (5-amino-2-methyl-6-(2,3,4,5,6-pentahydroxycyclohexyloxy)tetrahydropyran-3-yl)amino-α-iminoacetic acid, has a molecular formula of C 14 H 25N3O9. Kasugamycin is an agricultural antibiotic fungicide. Kasugamycin is highly systemic, rapidly absorbed by plants and transported throughout the body, exerting its bactericidal effects. It is effective against a variety of bacterial and fungal diseases, particularly rice blast. Kasugamycin acts on the amino acid metabolic esterase system of pathogens, disrupting protein biosynthesis and normal function of this system. This inhibits mycelial growth and causes cell granulation, rendering the pathogen incapable of reproduction and infection, thereby achieving the goal of disease control. Through the synergistic effects of these multiple pathways, it interferes with the normal physiological metabolism of pathogens, effectively inhibiting their growth and reproduction, thus achieving disease control. Pure kasugamycin appears as white crystals, while its hydrochloride salt appears as white needle-shaped or flaky crystals. The pure product is poorly soluble in organic solvents, dissolving 12.5% (w / v) in water at 25°C. The hydrochloride salt is readily soluble in water but insoluble in organic solvents such as methanol, ethanol, acetone, and benzene. It is relatively stable under acidic and neutral conditions. It is easily destroyed and ineffective when encountering alkaline solution.
[0023] Kasugamycin's properties: It has a broad fungicidal spectrum and is effective against a wide range of bacterial diseases, including bacterial wilt, soft rot, bacterial angular leaf spot, gummosis, rice blast, scab, leaf spot, and canker, among over 30 others. It also has some control effects against some fungal diseases, such as early blight, anthracnose, and gray mold. It has strong systemic penetration. After application, it is rapidly absorbed by plants and penetrates through the leaves to the underside, dispersing throughout the plant to rapidly kill pathogens. It is highly safe, with very low toxicity and low environmental residues, meeting modern environmental standards and making it suitable for the production of green and organic agricultural products. It also has a long-lasting effect: It resists rainwater erosion, adheres well to plants after application, is not easily washed away by rain, and maintains its fungicidal effect. It also has excellent compatibility with various fungicides, achieving significant synergistic effects. It has a certain regulatory effect on crop growth. While preventing and controlling a variety of diseases, it can also stimulate crop growth, induce plant resistance responses, and enhance plant immunity.
[0024] Kasugamycin's main drawbacks include: relatively weak killing ability. It's not very effective in killing pathogens directly, but rather acts as an inhibitor. It also has weak protective properties: While effective as a curative fungicide, its protective effect is relatively weak when used as a protective agent before a disease outbreak occurs. Some crops, such as legumes, are sensitive to kasugamycin, making it susceptible to developing resistance.
[0025] The performance advantages of copper oxychloride and kasugamycin combination
[0026] Broad bactericidal spectrum. Fungal disease control: Kasugamycin has a certain inhibitory effect on a variety of fungal diseases. Copper Oxide, as an inorganic copper preparation, also has good control effects on some common fungal diseases such as downy mildew, leaf mold, anthracnose, powdery mildew, etc. When the two are combined, they can act on a variety of fungal diseases at the same time, expanding the scope of bactericidal control. Bacterial disease control: Kasugamycin has an outstanding effect on the prevention and control of bacterial diseases and is a commonly used agent for the prevention and control of bacterial diseases. Copper Oxide can also inhibit the growth of bacteria to a certain extent. After the two are combined, the ability to prevent and control bacterial diseases is further enhanced, and the control effect of bacterial diseases such as bacterial leaf spot, bacterial soft rot, and ulcer disease is significantly improved.
[0027] Dual protective and therapeutic effects. Protective effect: Copper Oxide forms a physical protective film on the surface of crops, preventing pathogens from invading and protecting the crops. When applied before a disease strikes, it effectively prevents the onset of disease and reduces the chance of pathogen infection. Therapeutic effect: Kasugamycin is systemic and can be absorbed by crops and transported throughout the body, inhibiting and killing pathogens that have already invaded the crops, thereby achieving a therapeutic effect. The combined agent has both protective and therapeutic effects, achieving effective results both before disease onset and after disease onset. Strong adhesion and resistance to rain washoff: The combined agent has strong adhesion, adheres well to the crop surface, and is not easily washed away by rain, thus ensuring its effective duration. Effective control effects are maintained even in rainy seasons and environments. Rapidly repairs crop wounds: The combined agent has a rapid repair function for crop wounds, promoting wound healing, reducing the chance of pathogens invading through wounds, and lowering the risk of disease. This is particularly important for crops susceptible to mechanical damage or wounds caused by pests and diseases. Relatively safe: Compared to some highly toxic fungicides, copper oxychloride and kasugamycin are low-toxic fungicides, making them relatively safe for the environment and crops. When used appropriately, they will not have significant adverse effects on crop growth and development.
[0028] Copper oxychloride and kasugamycin combination can be used to prevent and control the following crop diseases:
[0029] Fruit trees: Such as citrus canker, grape downy mildew, powdery mildew, and gray mold. Vegetables: These include leaf mold of tomatoes and eggplants, downy mildew of cucumbers and bitter melons, black rot of cauliflower and purple cabbage, and bacterial rots of lettuce and chicory. Tobacco: It can be used to control tobacco leaf spot, hollow shank disease, bacterial angular leaf spot, and bacterial wilt. Beet: It has a certain control effect on snake eye disease, bacterial leaf spot, and root rot of beets. Medicinal plants: It can be used to control bacterial soft rot and leaf tip blight of lilies, powdery mildew of mint, and white rust of morning glory.
[0030] The ratio of copper oxychloride and kasugamycin when mixed
[0031] The realization of compounding copper oxychloride and kasugamycin, and preparing this inorganic pesticide that is "insoluble in both water and organic solvents" and phenylamide fungicide into a nanopesticide formulation, especially the realization of preparing copper oxychloride and kasugamycin into a suspension dispersion with a size of less than 100nm, will face huge technical challenges.
[0032] Generally, the mass ratio of copper oxychloride to the active ingredient of kasugamycin is in the range of 9 to 22.5:1.
[0033] 1. Technical Challenges
[0034] 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.
[0035] Most pesticides are insoluble in water but soluble in organic solvents. For these pesticides, the strategy for reducing particle size is to dissolve them in a solvent or complex solvent to form a monomolecular dispersed solution. This solution is then prepared into nanomicelles, nanocrystals, nanospheres, nanocapsules, nanogels, and various nanocarriers through various methods.
[0036] However, pesticides containing polyvalent metal ions are insoluble in both water and organic solvents, limiting their application in nanoscale manufacturing. Copper oxychloride is one such pesticide. Current technology makes it impossible to fully achieve nanoscale size through traditional mechanical crushing and ultrafine grinding processes, let alone scales below 100nm. Compounding inorganic pesticides like copper oxychloride with organic fungicides to create transparent nanoscale suspensions with particle sizes less than 100nm is a globally challenging problem.
[0037] 2. Innovation of the present invention
[0038] The invention uses copper chloride and a water-soluble base as reactants for generating copper oxychloride. By determining the molecular ratio of the reactants, the type and amount of a high-molecular surfactant (dispersant), and suitable reaction conditions (such as the method and speed of adding the reactants, stirring speed, temperature, and pH value), and utilizing the process of diluting the pesticide with water, a transparent and stable copper oxychloride nano-suspension dispersion of a certain concentration is prepared. Kasugamycin molecules are also dissolved in the system, thereby forming a copper oxychloride / kasugamycin nano-suspension dispersion, which can be directly used in spraying operations for preventing and controlling crop diseases.
[0039] The innovative features of the present invention are as follows:
[0040] (1) Innovative preparation of a copper oxychloride / kasugamycin nanosuspension dispersion. Unlike the micron-sized formulations of existing copper oxychloride / kasugamycin compound wettable powders, the copper oxychloride / kasugamycin nanosuspension prepared in this invention features copper oxychloride particles less than 100 nm in size, while kasugamycin is a monomolecular dispersion less than 1 nm, making it significantly innovative. The innovative approach to creating this nanosuspension dispersion involves separating the two water-soluble reactants that generate copper oxychloride into two components, one of which also contains kasugamycin and a water-soluble polymer additive. These two aqueous solutions are then subjected to a contact reaction under controlled conditions. Due to the ionic reaction, copper oxychloride molecules are quickly formed. As they nucleate and crystallize, they tend to precipitate from the water. The present invention adopts two preventive measures: first, one or more water-soluble polymeric surfactants of selected types and appropriate amounts are pre-added as dispersants to the aqueous dispersion system of the reaction, forming random coils in the aqueous solution; second, appropriate reaction conditions are selected, including reactant concentration, appropriate addition method and speed, appropriate stirring speed, and appropriate pH value, to control the formation, nucleation, and crystallization growth rates of copper oxychloride. Thus, when copper oxychloride crystals in the system are very small, they are evenly dispersed into the random coils formed by the polymeric dispersant under stirring. The random coil network structure prevents the crystals from colliding with each other and from growing, thereby ensuring suspension, dispersion, and stability. Furthermore, kasugamycin in the system does not participate in the reaction. As long as the copper oxychloride nanoparticle size is less than 100 nm, the copper oxychloride / kasugamycin nanosuspension dispersion will be transparent.
[0041] (2) The copper oxychloride / kasugamycin nanosuspension 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 nanoproduct size, but is also smaller than the particle size of existing copper oxychloride / kasugamycin wettable powders. Traditional wettable powders typically have particle sizes above the micron level. Significantly reducing the particle size dramatically increases the number of particles, allowing for more effective contact with the target, improving control effectiveness, and reducing dosage.
[0042] (3) The innovative preparation method for the copper oxychloride / kasugamycin nanosuspension dispersion eliminates the existing copper oxychloride technical synthesis and formulation processes, as well as the corresponding plant and equipment. By utilizing the pesticide dilution process, the copper oxychloride reactants are separated into two components and mixed in a specific addition pattern, resulting in a copper oxychloride / kasugamycin nanosuspension 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 processing processes and equipment required for compounding wettable powders. This not only reduces synthesis and processing costs, eliminating the need for expensive equipment, but also simplifies the process, facilitates operation, and is environmentally friendly and energy-efficient.
[0043] (4) The concentration of the copper oxychloride / kasugamycin nanosuspension dispersion can be adjusted based on crop type and disease control needs. Using the copper oxychloride / kasugamycin nanosuspension dispersion, the water dosage for dilution and spraying can be determined based on the crop type and growth conditions. The concentration of the copper oxychloride / kasugamycin active ingredient to be sprayed can then be determined based on the severity of the disease. This allows for precise determination of the dosage of copper oxychloride / kasugamycin and the amount of the water-soluble polymer dispersant.
[0044] 3. Technical ideas of the present invention
[0045] The reactants for copper oxychloride formation can be copper chloride and an alkali compound (sodium hydroxide, potassium hydroxide, ammonium hydroxide), both of which are water-soluble and dispersed monomolecularly in water. When the two interact, ion exchange reactions easily form copper oxychloride molecules. However, the addition of a water-soluble aqueous solution of kasugamycin to one of the components does not participate in the reaction.
[0046] The above ingredients can be divided into two-component or three-component solutions, based on the principle that the components do not react with each other, and that packaging is simple and convenient to use. Copper chloride can be used as component A, the alkaline compound can be used as component B, and the required water-soluble polymer additive can be used as component C. Kasugamycin can be added to either component A or component C. For convenience, a two-component solution can also be simplified, with component C added to component A. Component A in the two-component solution is equivalent to "component A + component C" in the three-component solution.
[0047] In the system, components A and B meet and react 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 effect 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, form 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.
[0048] During the nanoparticle formation process, the addition rate of components, the stirring rate, and the diffusion rate of reactants and products—the amount added per unit time and the degree of dispersion—are key factors influencing nanoparticle size. Regarding the addition rate, if the goal is to produce nanoparticles less than 100 nm in size, the clarity and transparency of the system is the key criterion. This theory is based on the assumption 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 the system is therefore transparent. Conversely, if the system exhibits opalescence or opacity, it indicates a particle size greater than 100 nm. Kasugamycin in the system does not participate in this process.
[0049] To achieve this goal, the following points must be focused on:
[0050] ⑴ Controlling the reaction rate of copper oxychloride molecules, the speed of grain formation, and the speed of aggregation and growth is the key to obtaining particles smaller than 100nm. This involves factors such as the concentration of reactants in the reaction area, the diffusion rate, the type and amount of water-soluble polymer dispersant, the amount of dilution water, and the 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 / kasugamycin nanosuspension dispersion of the present invention, alkali reacts with copper chloride to form copper oxychloride, while controlling the addition method, speed, and stirring speed, and kasugamycin dissolved in water is present. The system is composed of copper chloride, an alkali compound, kasugamycin, 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, kasugamycin, 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, it refers to the size of the copper oxychloride grains 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 invention utilizes water as a dispersion medium in pesticide formulations, which usually needs to be diluted with water before spraying, to achieve the reaction of copper chloride and alkali to form copper oxychloride. Water-soluble kasugamycin is present in the system, thereby providing an apparently water-soluble and transparent copper oxychloride / kasugamycin nanosuspension dispersion that can be directly used for spraying.
[0076] The copper oxychloride / kasugamycin nano-suspension dispersion of the present invention can be loaded into a pesticide spraying device for spraying, and is used for preventing and treating various diseases of fruit trees, vegetables, tobacco, sugar beets and medicinal plants.
[0077] The copper oxychloride / kasugamycin nano-suspension dispersion of the present invention refers to a mixed dispersion consisting of a copper oxychloride suspension dispersion of less than 100 nanometers and kasugamycin dissolved in water; the copper oxychloride / kasugamycin 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, kasugamycin, 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 dispersant may be selected from (at least one) water-soluble natural polymers and their derivatives, including starch, cellulose, guar gum, chitosan, and their derivatives; aliphatic, aliphatic aromatic, aliphatic phenolic, arylphenolic, and oleyl polyoxyethylene ethers; aliphatic ether 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] Nanosuspensions below 100nm
[0087] In order to improve the efficacy of nano-scale copper oxychloride / kasugamycin, 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 increased particles is also different. For example, if the usual 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 nanoscale copper oxychloride / kasugamycin, 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 one dimension. Second, pesticide particles between 1 and 100 nm form a colloidal solution, are apparently water-soluble, and have a clear, transparent appearance. 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 / kasugamycin nanosuspension dispersion
[0090] The concentration of the copper oxychloride / kasugamycin 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 / kasugamycin compound wettable powder as an example, for use in preventing and treating citrus canker, a reported dosage of the active ingredient is 90 / 10 g / mu (1 mu = 1 / 15 hectare, the same below). The typical water consumption is 150-200 kg / mu. In this case, the dilution concentrations of copper oxychloride and kasugamycin are 0.06%, 0.0067%-0.045%, and 0.005%, respectively. Due to the small particle size and high efficacy of the nano-suspension dispersion of the present invention, the dosage can be reduced to 80 / 9 g / mu. If the water consumption is 150 kg / mu, the concentrations of the copper oxychloride / kasugamycin nano-suspension dispersion in the dilution are approximately 0.053% and 0.006%, respectively.
[0091] Stable period
[0092] The copper oxychloride / kasugamycin nano-suspension dispersion prepared by the present invention is a colloidal solution that is transparent in appearance and appears to be 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 / kasugamycin suspoemulsion dispersion is prepared, the required operating time should be at least more than 1 hour, so the length of the stable period can be described in hours. Therefore, the present invention proposes the concept of a "stable period" for nano-scale copper oxychloride suspension dispersions below 100nm. That is, the copper oxychloride / kasugamycin nano-suspension dispersions below 100nm prepared by the present invention complete the spraying operation within the period when the solution remains transparent, and the stable period should reach 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 / kasugamycin suspension 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 the nano-copper oxychloride / kasugamycin suspension emulsion. During the stable period, the suspension emulsion 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 observes the phenomenon of the stable period of the copper oxychloride / kasugamycin suspension dispersion liquid with a size below 100 nanometers, and is applicable to stable periods of different hour 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 / kasugamycin nanosuspension dispersion
[0106] Traditional copper oxychloride single-ingredient and binary formulations typically consist of only one component and can be sprayed after dilution with water. However, the copper oxychloride particles are typically larger than micrometers in size. To produce a nanoscale copper oxychloride / kasugamycin nanosuspension dispersion, the present invention utilizes at least two components. By diluting the suspension with water according to a specific method, a copper oxychloride / kasugamycin 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 scheme of the copper oxychloride / kasugamycin 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, kasugamycin and water.
[0111] Component A is a transparent aqueous solution containing copper chloride, a precursor of copper oxychloride, and kasugamycin. In the aqueous solution, copper oxychloride and kasugamycin are both dissolved in water as monomolecules.
[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, and potassium hydroxide. Component B can be a solid (for strong bases) or an aqueous solution. Ammonium hydroxide can only be an aqueous solution. Preferably, it is an aqueous solution of ammonium hydroxide, or a combination of an aqueous solution of ammonium hydroxide and one of the other two.
[0114] Component C: It is composed of at least one water-soluble surfactant, or its aqueous solution, which is an auxiliary agent that disperses, suspends and stabilizes the generated copper oxychloride nanoparticles.
[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 embodiment is that component C is composed of a water-soluble surfactant and kasugamycin. In order to reduce the viscosity and dissolve kasugamycin, an appropriate amount of water should 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 and its derivatives; polyoxyethylene ether derivatives such as aliphatic, aliphatic phenolic, arylphenolic, and oleyl groups; sulfates and sulfonates of aliphatic ethers; 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 copper oxychloride / kasugamycin nanosuspension dispersion with a size of less than 100 nanometers, which has a stability period of hours and is a system generated by a mixing reaction of two components. They are:
[0123] Component A: An aqueous solution consisting of copper chloride, kasugamycin, a water-soluble polymer surfactant, and water. This solution consists of copper chloride and kasugamycin, the precursors required to generate copper oxychloride / kasugamycin particles sized below 100 nanometers, a water-soluble polymer surfactant for dispersion, suspension, and stabilization, 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 high molecular 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 amount 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 / kasugamycin produced by "tank mixing" is a directly usable copper oxychloride / kasugamycin nanosuspension dispersion. A water-soluble dispersing polymer additive is added to this solution, resulting in the copper oxychloride being dispersed and suspended at the nanoscale in the polymer additive solution. Because the particles are less than 100 nanometers in size, the resulting copper oxychloride / kasugamycin nanosuspension dispersion is transparent and apparently water-soluble.
[0131] (2) The water-soluble polymer additive with 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.
[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] ⑸ The copper oxychloride / kasugamycin nanosuspension dispersant, copper oxychloride is directly generated by the reaction of copper chloride and ammonium hydroxide during the dilution process with water before use. The amount of water-soluble polymer additives used is related to the amount of copper oxychloride generated by the system and the amount of dilution water. For example, when the effective ingredient of copper oxychloride / kasugamycin used to prevent and control tomato leaf mold is 40 / 2 g / mu and the spraying water volume is 50 kg / mu, the concentration of the effective ingredient is 0.08% and 0.004% g / kg, respectively. By controlling the amount of water-soluble polymer additives, the stability of the copper oxychloride / kasugamycin nanosuspension dispersion can be adjusted. The concentration of the water-soluble polymer additive should not be less than 0.2%.
[0135] (6) The copper oxychloride / kasugamycin nanosuspension dispersion is directly generated during the dilution process before spraying, i.e., the two components are mixed and reacted at a specific concentration and in a specific mixing method. This innovative method not only eliminates the synthesis and purification process of copper oxychloride technical preparation by pesticide manufacturers, but also eliminates the multi-step process of converting copper oxychloride and kasugamycin technical into traditional wettable powders by pesticide formulation manufacturers. The solution proposed by the present invention can be directly applied to the plant protection stage of agricultural production. The process is significantly environmentally friendly and energy-saving, can reduce production costs, improve drug efficacy, and achieve a synergistic effect of reducing dosage.
[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 product. Copper chloride reacts rapidly with strong bases, and when the system pH is between 12 and 14, copper oxychloride precipitates quickly. This is detrimental to obtaining grains smaller than 100 nm. Because NH₄OH is a weak base and reacts mildly with CuCl₂, a system pH of 7 to 8 results in slower copper oxychloride precipitation, which helps control the grain growth rate. Mild reaction conditions are beneficial for obtaining copper oxychloride grains smaller than 100 nm. A lower pH value also contributes to the stability of copper oxychloride / kasugamycin formulations.
[0142] 2. Control of reaction conditions for preparing copper oxychloride / kasugamycin nanosuspension
[0143] The preparation of nano-sized copper oxychloride and kasugamycin 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, which is marked by a transparent dispersion. Kasugamycin dissolved in water, on the other hand, is merely a dilution process. 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. The reaction conditions that need to be considered include:
[0144] ⑴ Component division and dilution water allocation. The principles of component division are, first, that the reacting components must be separated into different components, and second, that it facilitates packaging and eases operation. The optimized solution is a two-component solution, one consisting of the precursor copper chloride, kasugamycin, a water-soluble polymer dispersant, and water, and the other an alkaline aqueous solution. The amount of dilution water determines the concentration of the active ingredient in the product. The allocation ratio depends on the order in which the components are added, whether component A is added first, then component B, or in reverse order. Generally, the allocation ratio of the added component should be smaller than that of the added component to facilitate thorough mixing and shorten the 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 / kasugamycin nanosuspension 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 / kasugamycin 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, kasugamycin, a selected water-soluble polymer dispersant, and water. This is a mixed aqueous solution consisting of the metallic copper compound required to produce copper oxychloride particles sized below 100 nanometers, water-soluble kasugamycin, a water-soluble polymer dispersant for dispersion and suspension, and water.
[0156] In the preparation of component A, since water-soluble polymer additives are more difficult to dissolve in water than small molecules, they should be added to the allocated amount of water first, stirred to dissolve, then the precursor is added, stirred to dissolve, and then kasugamycin 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 / kasugamycin nanosuspension dispersion is clear, transparent, and apparently water-soluble, making it suitable for spraying to control crop diseases. The time it takes for the transparent dispersion to precipitate is observed; this time period represents the spraying period.
[0166]
Brief description of the attached drawings
[0167] Figure 1: Flowchart for the preparation of copper oxychloride / kasugamycin nanosuspension dispersion (two components)
[0168] Figure 2: Flowchart for the preparation of copper oxychloride / kasugamycin nanosuspension dispersion (three components)
[0169] [Implementation Method]
[0170] Example 1.
[0171] A copper oxychloride / kasugamycin nanoemulsion dispersion can be used to control tomato leaf mold. A reported dosage of 45 g / 2 g of the active ingredient of copper oxychloride / kasugamycin per mu (approximately 200 sq ft) was used, with a dilution water requirement of 50 kg. Considering the high efficacy of nanopesticides, this example selected a dosage of 36 g / 2 g of the active ingredient of copper oxychloride / kasugamycin per mu (approximately 200 sq ft), with a dilution water requirement of 50 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 4 / 5 (40 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 / 5 (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 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 always transparent until component B is added.
[0178] A transparent copper oxychloride / kasugamycin nano-suspension dispersion was obtained, which can be directly used for spraying tomatoes. The stability time of the copper oxychloride / kasugamycin nano-suspension dispersion was observed and the stability time was 5 hours.
[0179] Example 2.
[0180] A copper oxychloride / mancozeb nanoparticle suspension dispersion can be used to control downy mildew on litchi trees. A reported dosage of the two active ingredients, copper oxychloride / kasugamycin, is 110 / 5 g / mu, with a dilution water requirement of 200 kg. Considering the high efficacy of nanopesticides, this example uses a copper oxychloride / kasugamycin active ingredient dosage of 90 / 5 g / mu, with a dilution water requirement of 200 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] (1) In an appropriate container, add water in a distribution ratio of 9 / 10 (180 kg), add component A, stir and dissolve to obtain a transparent diluted aqueous solution of component A.
[0185] (2) Add component C to the diluted aqueous solution of component A, 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 / 10 (20 kg), add component B, stir and dissolve to obtain a transparent diluted aqueous solution of component B.
[0187] (4) Under pre-stirring, add the diluted aqueous solution of component B to the mixed diluted aqueous solution of "component A + component C" in a continuous spraying manner, controlling the addition speed and stirring speed to keep the system transparent until the diluted solution of component B is added.
[0188] A transparent copper oxychloride / kasugamycin nano-suspension dispersion was obtained, which can be directly used for spraying litchi. The stability time of the copper oxychloride / kasugamycin nano-suspension dispersion was observed and found to be 4.5 hours.
Claims
1. A copper oxychloride / kasugamycin nano-suspension dispersion, wherein the copper oxychloride / kasugamycin nano-suspension dispersion is a copper oxychloride / kasugamycin 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, kasugamycin, 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, the generated copper oxychloride particles are dispersed in a random coil morphology structure formed by the water-soluble polymer dispersant dissolved in water.
2. The copper oxychloride / kasugamycin 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 / kasugamycin nano-suspension dispersion according to claim 1, characterized in that: The water-soluble polymer dispersant is at least one of the following options: Water-soluble natural polymers and their derivatives, including starch, cellulose, guar gum, chitosan and their derivatives; fatty, fatty aromatic, fatty phenolic, aromatic phenolic, and oily polyoxyethylene ethers; fatty polyether sulfates and sulfonates; Tween and alkyl polyglycosides; Or water-soluble synthetic polymers, polyvinyl pyrrolidone, polyvinyl alcohol, sodium polyacrylate, polystyrene-maleate, etc., polyoxyethylene-polyoxypropylene-polyoxyethylene block copolymers; Water-soluble natural polymers and their derivatives are preferred.
4. The copper oxychloride / kasugamycin nano-suspension dispersion according to claim 1, characterized in that The copper oxychloride / kasugamycin nanosuspension dispersion has a stability period of hours.
5. The copper oxychloride / kasugamycin nano-suspension dispersion according to claim 1, characterized in that The ratio of the amount of the water-soluble surface dispersant to the amount of dilution water is not greater than 1:
800.
6. A copper oxychloride / kasugamycin nano-suspension dispersion, wherein the copper oxychloride / kasugamycin nano-suspension dispersion is a copper oxychloride / kasugamycin 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, kasugamycin 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, generate copper oxychloride particles dispersed in a random coil morphology structure formed by the water-soluble polymer dispersant dissolved in water.
7. The copper oxychloride / kasugamycin nano-suspension dispersion according to claim 6, characterized in that , the component B is selected from at least one of sodium hydroxide, potassium hydroxide and ammonium hydroxide; preferably, an aqueous solution of ammonium hydroxide, or a combination of an aqueous solution of ammonium hydroxide and one of the other two.
8. The copper oxychloride / kasugamycin nano-suspension dispersion according to claim 6, characterized in that The copper oxychloride / kasugamycin nanosuspension dispersion has a stability period of hours.
9. The copper oxychloride / kasugamycin nano-suspension dispersion according to claim 6, characterized in that , the water-soluble polymer dispersant is a surfactant selected from natural substances and their derivatives and synthetic polymers; Preferably, it is selected from starch, cellulose, guar gum, chitosan and its derivatives; polyoxyethylene ether derivatives such as aliphatic, aliphatic aromatic, aliphatic phenolic, aromatic phenolic, and oleyl; aliphatic polyether sulfates and sulfonates; Tween and alkyl polyglycosides.
10. A method for preparing a copper oxychloride / kasugamycin 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 the copper oxychloride / kasugamycin nano-suspension dispersion; Alternatively, the component B dilution is pre-stirred, 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 / kasugamycin nano suspension dispersion; Component A: an aqueous solution consisting of copper chloride, kasugamycin, 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.
11. The preparation method according to claim 10, characterized in that ,The adding methods include intermittent adding, continuous dripping adding, and continuous or intermittent spraying adding.
Citation Information
Patent Citations
Tribasic copper chloride microspheres, preparation method thereof and feed additive
CN111642633A
Aqueous suspension-like agrochemical composition
JP1999012116A
Method for preparing miscible nano-pesticide suspension
WO2020136451A1