A microcapsule suspension-suspension containing chlorofluoro and clothianidin and a preparation method thereof

Abstract

The application belongs to the technical field of pesticide suspending agent, and specifically discloses a micro-capsule suspending-suspending agent containing chlorfluazuron and clothianidin and a preparation method thereof. The micro-capsule suspending-suspending agent containing chlorfluazuron and clothianidin comprises the following raw materials: 11-13% of high-efficiency chlorfluazuron, 12-14% of clothianidin, 9.20-9.60% of solvent, 3.25-3.45% of wall material one, 0.35-0.50% of protective glue, 2.13-2.33% of emulsifier, 1.24-1.45% of dispersant one, 0.24-0.45% of wall material two, 3.90-4.10% of dispersant two, 2.92-3.12% of antifreeze, 0.03-0.07% of thickening agent one, 0.45-0.55% of thickening agent two, 0.46-0.52% of preservative, and water supplement. The micro-capsule suspending-suspending agent prepared in the application has good stability during storage, controls slow release of effective components, and prolongs the effective period.

Description

Technical Field

[0001] This application relates to the technical field of pesticide suspensions, and in particular to a microcapsule suspension containing chlorfluoride and thiamethoxam and its preparation method. Background Technology

[0002] Microcapsule suspensions containing chlorpyrifos and thiamethoxam are insecticide mixtures of neonicotinoid and pyrethroid pesticides. They are usually formulated by combining high-efficiency chlorpyrifos and thiamethoxam, and have the characteristics of broad insecticidal spectrum, fast action, and long residual effect. They have systemic, contact and stomach poison effects on pests, knock down quickly and have a long-lasting effect. They have a good control effect on wheat aphids.

[0003] High-efficiency cyhalothrin is a pyrethroid insecticide that acts on the nerve membrane of pests, opening sodium ion channels and disrupting nerve conduction. Thiamethoxam belongs to the second-generation neonicotinoid insecticides, which mainly act on the nervous system of pests. By inhibiting acetylcholine receptors, it blocks the normal conduction of the pest's nervous system, thereby causing the pest to become paralyzed and die. The combination of the two has a synergistic effect.

[0004] Microcapsule suspensions, also known as water capsule suspensions, are homogeneous suspensions in which the active ingredient (core) is encapsulated by the capsule wall, forming microcapsules that are uniformly dispersed and stably suspended in water. The capsule particle size is generally between 1-20 μm. The core is slowly released under the control of the capsule wall to achieve an insecticidal effect. However, existing microcapsule suspensions may experience stratification, sedimentation, or capsule wall aging during long-term storage, which can reduce efficacy. Summary of the Invention

[0005] To address the issue of poor stability during long-term storage of microcapsule suspensions, this application provides a microcapsule suspension containing chlorfluoride and thiamethoxam, and its preparation method.

[0006] This application provides a microcapsule suspension-suspension agent containing chlorfluazuron and thiamethoxam, using the following technical solution:

[0007] A microcapsule suspension-suspension agent containing chlorpyrifos and thiamethoxam, comprising the following raw materials by mass percentage: 11-13% lambda-cyhalothrin, 12-14% thiamethoxam, 9.20-9.60% solvent, 3.25-3.45% wall material I, 0.35-0.50% protective colloid, 2.13-2.33% emulsifier, 1.24-1.45% dispersant I, 0.24-0.45% wall material II, 3.90-4.10% dispersant II, 2.92-3.12% antifreeze, 0.03-0.07% thickener I, 0.45-0.55% thickener II, 0.46-0.52% preservative, and water to make up the difference.

[0008] By employing the above technical solutions, high-efficiency cyhalothrin exhibits contact and stomach poison effects, possesses a broad insecticidal spectrum, and is highly effective against lepidopteran and coleopteran pests such as aphids, cabbage caterpillars, and cotton bollworms. However, its residual effect is short-lived, and it is prone to developing resistance. Thiamethoxam has systemic, contact, and stomach poison effects, and is highly effective against piercing-sucking pests (such as aphids and planthoppers) and underground pests (such as grubs). It has a longer residual effect, and when combined with pyrethroid pesticides, it can complement the insecticidal spectrum and delay the development of resistance. Wall material one and wall material two form the microcapsule shell, controlling the slow release of the active ingredient and prolonging the residual effect. The protective colloid helps stabilize the capsule wall structure, preventing the microcapsules from rupturing or aggregating during preparation or storage. The emulsifier reduces the interfacial tension between the oil and aqueous phases, promoting the dispersion of the oil phase into tiny droplets, providing a basis for encapsulation.

[0009] Dispersants 1 and 2 prevent microcapsule particle aggregation and maintain suspension stability. Thickeners 1 and 2 adjust the viscosity of the suspension, prevent microcapsule sedimentation, and improve pouring and spraying performance. Antifreeze lowers the freezing point of the system, preventing freezing and demulsification during low-temperature storage. Preservatives inhibit microbial growth and prevent mold growth in the formulation. The synergistic effect of multiple adjuvants ensures the stability of the formulation during storage and transportation, providing a long-lasting effect that combines rapid and sustained action, thus expanding the target pests.

[0010] Preferably, the composition includes 12% high-efficiency cyhalothrin, 13% thiamethoxam, 9.40% solvent, 3.35% wall material one, 0.45% protective colloid, 2.23% emulsifier, 1.34% dispersant one, 0.34% wall material two, 4.00% dispersant two, 3.00% antifreeze, 0.05% thickener one, 0.50% thickener two, 0.50% preservative, and water to make up the difference.

[0011] By adopting the above technical solutions, the component values ​​of each raw material are further defined, and the components work synergistically to achieve excellent overall effects. The combination of pyrethroids and neonicotinoids combines rapid and sustained efficacy, expanding the target pests. Encapsulation with wall materials reduces the contact between the active ingredients and the external environment, lowering the risk of photosynthesis and hydrolysis. Through scientific formulation and optimized formulation technology, efficacy, duration of effect, and safety are balanced, making it suitable for the needs of modern agricultural green pest control.

[0012] Secondly, this application also provides a method for preparing a microcapsule suspension-suspension agent containing chlorfluazuron and thiamethoxam, comprising the following steps:

[0013] (1) Mix the protective colloid, emulsifier, dispersant 1 and water evenly to obtain the aqueous phase;

[0014] (2) Stir the high-efficiency cyhalothrin, thiamethoxam and solvent at 55-60℃ to obtain the oil phase, add wall material one, mix with the water phase, emulsify, raise the temperature to 30℃, add wall material two, raise the temperature to 60℃, stir and solidify to obtain the primary emulsion.

[0015] (3) Add dispersant II, antifreeze, thickener I, thickener II, and preservative to the primary emulsion, stir, and obtain a microcapsule suspension-suspension containing chlorfluoride and thiamethoxam.

[0016] By adopting the above technical solution, the protective colloid, emulsifier, and dispersant are dispersed in water to form a uniform medium, which provides a stable carrier for the subsequent addition of the oil phase, ensuring that the oil phase can be uniformly dispersed in it and avoiding local aggregation or stratification.

[0017] High-efficiency cyhalothrin and thiamethoxam are dispersed in a solvent to form a stable oil phase. Wall material one is then added, and wall material one is uniformly dispersed in the oil phase, becoming a hydrophobic reactive monomer for the microcapsule shell, preparing for subsequent reaction with the hydrophilic wall material in the aqueous phase.

[0018] When the oil phase and the water phase are mixed, emulsification occurs under shear force. The emulsifier in the water phase is oriented at the oil-water interface, reducing the interfacial tension and breaking the oil phase into micron-sized droplets. The protective colloid and dispersant in the water phase are further adsorbed onto the droplet surface, forming a temporary protective film to prevent droplet aggregation and maintain the stability of the emulsion.

[0019] Wall material two is a hydrophilic amine compound, readily soluble in the aqueous phase. It reacts with wall material one to form a polyurethane polymer shell on the droplet surface, initially encapsulating the effective components in the oil phase. Stirring and curing ensure uniform shell reaction on the surface of each oil phase droplet, ultimately forming structurally stable microcapsules (the oil phase core is completely encapsulated by the polymer shell).

[0020] In step (3), dispersant two maintains the long-term dispersion stability of the primary emulsion, while thickener one and thickener two regulate the viscosity of the system, enhance suspension, and prevent subsequent microcapsule sedimentation while ensuring uniform atomization during application. The resulting microcapsule suspension-suspension containing chlorfluazuron and thiamethoxam is stable in storage, convenient to use, and resistant to environmental interference.

[0021] Preferably, the protective adhesive is a gelatin complex, and the preparation method of the gelatin complex includes the following steps:

[0022] Acryloylglycine was dispersed in HCl solution, nano-silica was added, and the mixture was stirred at 50-55℃ for 1-1.5 h. The solution was then neutralized with NaOH to pH=7.0 to obtain the active monomer solution.

[0023] Gelatin was dispersed in a phosphate buffer solution, methacrylic anhydride was added, and the mixture was reacted at 40-45°C for 1.5-2 hours to obtain mixture one.

[0024] Under light-protected conditions, an active monomer solution, hydroxyethyl methacrylate, and photoinitiator 1173 were added to mixture one, and crosslinking was carried out under ultraviolet light irradiation to obtain mixture two. The mixture was washed with water, dried, and ground to obtain a gelatin complex.

[0025] By adopting the above technical solution, the acidic dispersion medium promotes the dissolution of acryloylglycine, and the nano-silica is dispersed in the system, which improves the mechanical strength and thermal stability of the system, creating conditions for subsequent bonding with gelatin.

[0026] Gelatin is dissolved in phosphate buffer to form a colloidal solution. Methacrylamide reacts with the amino groups in the gelatin molecules to form an acylation reaction. The modified gelatin molecules have polymerizable double bonds, which provide anchor points for subsequent cross-linking reactions.

[0027] Acryloyl groups on modified gelatin, acryloyl groups in the active monomer, and hydroxyethyl methacrylate undergo free radical copolymerization under the action of a photoinitiator, forming a three-dimensional cross-linked network. Upon ultraviolet irradiation, photoinitiator 1173 decomposes to generate active free radicals, initiating the opening and interconnection of double bonds. Ultimately, gelatin, nano-silica, and functional monomers are covalently fixed within the cross-linked network, forming a structurally stable complex. As a microcapsule wall material or auxiliary wall material, it achieves efficient encapsulation of active ingredients, exhibiting excellent film-forming ability. The amino and hydroxyl groups in its molecules can form weak interactions with the active ingredients, ensuring stable encapsulation of the core material and reducing leakage during the encapsulation process. Furthermore, the gelatin complex contains nano-silica, which can form an "organic-inorganic hybrid wall material" with the organic phase of gelatin, compensating for the poor water resistance and easy swelling defects of pure gelatin wall materials.

[0028] Preferably, the mass ratio of acryloylglycine, nano-silica, gelatin and hydroxyethyl methacrylate is 0.3-0.4:0.4-0.5:1:0.2-0.3.

[0029] By employing the above technical solution, further limiting the mass ratio of acryloylglycine, nano-silica, gelatin, and hydroxyethyl methacrylate within a certain range, the resulting gelatin composite exhibits better mechanical properties. Acryloylglycine, containing an acryloyl group in its molecular structure, can undergo free radical polymerization with other molecules containing unsaturated bonds under ultraviolet light initiation. Simultaneously, its glycine group carries polar amide and amino bonds, which can interact with the peptide bonds and hydroxyl groups of gelatin through hydrogen bonds, improving its compatibility with gelatin. Hydroxyethyl methacrylate contains both acryloyl and hydroxyl groups; the acryloyl group synergistically with the acryloyl group of acryloylglycine undergoes a cross-linking reaction under photoinitiation, increasing the density of the cross-linked network.

[0030] The surface of nano-silica is rich in hydroxyl groups, which bind to the amide groups of acryloylglycine, the hydroxyl groups of hydroxyethyl methacrylate, and the polar groups of gelatin through hydrogen bonds. It is uniformly dispersed in the organic network formed by acryloylglycine and hydroxyethyl methacrylate, forming an organic-inorganic interpenetrating network. This enhances the mechanical strength and environmental resistance of the microcapsule wall material, optimizes surface properties to maintain suspension stability, and provides key performance support for microcapsule suspensions containing chlorine and thiamethoxam.

[0031] Preferably, the emulsifier is composed of calcium dodecylbenzenesulfonate, phenylethylphenol polyoxyethylene ether, and tea polyphenols in a mass ratio of 1:0.6-0.7:0.2-0.3.

[0032] By employing the above technical solution, the calcium dodecylbenzenesulfonate molecule contains hydrophilic sulfonic acid groups and hydrophobic alkylbenzene chains. This reduces the surface tension between the oil and aqueous phases, allowing the oil phase to be uniformly dispersed in the aqueous phase to form a stable emulsion. Phenethylphenol polyoxyethylene ether, with its strong hydrophilicity, can work in conjunction with calcium dodecylbenzenesulfonate to further enhance the emulsification effect and improve the stability of the emulsion. Tea polyphenols not only assist in emulsification but also possess antioxidant properties, inhibiting the degradation of active ingredients in microcapsules due to oxidation, extending the shelf life of the formulation, and, in conjunction with the wall material, improving the stability of the microcapsules. The three components are compounded in a specific mass ratio to fully utilize the synergistic effect of anionic and nonionic emulsifiers, balancing emulsification efficiency and stability. Simultaneously, the antioxidant properties of tea polyphenols provide favorable conditions for the preparation and storage of microcapsule suspensions, ensuring that the formulation maintains good dispersibility and efficacy within its shelf life.

[0033] Preferably, the first dispersant is modified sodium lignosulfonate, the second dispersant is sodium lignosulfonate, and the preparation method of the modified sodium lignosulfonate includes the following steps:

[0034] (1) Add sodium lignosulfonate to water, stir at 70-72℃ for 40-45 min, add metal-organic framework, continue stirring for 0.5-0.6 h, dry to obtain mixture;

[0035] (2) Disperse β-cyclodextrin and polyvinylpyrrolidone in deionized water, add the mixture from step (1), stir at 40-42℃ for 0.5-0.7h, dry, grind, and obtain modified sodium lignin sulfonate.

[0036] By employing the above technical solution, heating causes the sodium lignosulfonate molecular chains to unwind from their entangled state, fully exposing hydrophilic groups such as sulfonic acid groups and phenolic hydroxyl groups, thereby enhancing water solubility and interfacial activity and providing reaction sites for subsequent reactions. Metal-organic frameworks (MOFs) possess porous structures, high specific surface areas, and abundant active sites, and can bind to sodium lignosulfonate through physical adsorption or coordination, enhancing its loading capacity, specific surface area, and functionality.

[0037] The hydrophobic cavity of β-cyclodextrin can encapsulate small pesticide molecules (such as lambda-cyhalothrin), while its hydrophilic outer surface ensures compatibility with the aqueous phase, achieving a dual function of loading and sustained release. Polyvinylpyrrolidone has good dispersibility and compatibility, and binds to lignin and metal-organic frameworks through polar interactions. Its long-chain structure forms steric hindrance, further inhibiting the aggregation of composite particles.

[0038] Modified sodium lignosulfonate has good dispersibility, can increase pesticide loading capacity, and has good sustained-release ability.

[0039] Preferably, the mass ratio of sodium lignosulfonate, metal-organic framework and β-cyclodextrin is 1:0.3-0.4:0.15-0.2.

[0040] By adopting the above technical solution, the mass ratio of sodium lignosulfonate, metal-organic framework and β-cyclodextrin is further limited within a certain range. Through the complementary structure and function of the three, a significant synergistic effect is generated, and excellent performance is shown in terms of dispersion stability, adsorption loading and interface regulation.

[0041] The sulfonic acid groups on the sodium lignosulfonate molecular chain are negatively charged, which can prevent particle aggregation through electrostatic repulsion; at the same time, its hydrophilic groups (hydroxyl and carboxyl groups) bind to water molecules, giving the system good water solubility. When mixed with metal-organic frameworks and β-cyclodextrin, sodium lignosulfonate can be coated on the surface of the metal-organic framework and the surface of β-cyclodextrin particles through adsorption or hydrogen bonding. Utilizing electrostatic repulsion and steric hindrance, both can be uniformly dispersed in the aqueous phase or other systems, avoiding sedimentation or stratification.

[0042] β-Cyclodextrin molecules are rich in hydrophilic hydroxyl groups, which enhance their affinity for water molecules and further improve the dispersion stability of the metal-organic framework and sodium lignosulfonate in the aqueous phase. Simultaneously, its cyclic structure can bind to hydrophobic segments in sodium lignosulfonate molecules through inclusion bonding, reducing entanglement between sodium lignosulfonate molecules and indirectly optimizing dispersion. The mixture of these three components increases the loading rate and stability of pesticide active ingredients (such as chlorfluazuron and thiamethoxam), achieving improved water solubility and controlled sustained release of hydrophobic drugs.

[0043] Preferably, the thickener is composed of xanthan gum, sodium alginate, and fatty alcohol polyoxyethylene ether in a mass ratio of 1:0.6-0.7:0.1-0.2.

[0044] By employing the above technical solutions, xanthan gum, with its abundant hydrophilic groups in its molecular structure, can form a high-viscosity pseudoplastic fluid in water, significantly increasing the viscosity of the suspending agent, effectively inhibiting the sedimentation of microcapsule particles, and maintaining the homogeneity of the system. Simultaneously, the three-dimensional network structure formed by xanthan gum can encapsulate water and other components, enhancing the suspending agent's anti-stratification ability. Sodium alginate, with its carboxyl groups and other groups on its molecular chain, can form hydrogen bonds with water, further increasing the system viscosity. Furthermore, sodium alginate possesses certain film-forming and gelling properties, and can synergistically work with xanthan gum to strengthen the structural stability of the suspending agent and reduce collision and aggregation of microcapsules during storage or transportation.

[0045] The interaction between fatty alcohol polyoxyethylene ether and xanthan gum and sodium alginate molecules modulates the rheology of the system, resulting in a gentler thickening effect. Simultaneously, its surface activity helps improve the compatibility of microcapsule particles with the dispersion medium, reducing interparticle repulsion and indirectly enhancing the stability of the suspension. When combined, xanthan gum and sodium alginate, as the main thickening components, provide basic viscosity and structural support, while fatty alcohol polyoxyethylene ether optimizes the thickening effect by regulating interfacial interactions and intermolecular interactions. Together, they ensure that the microcapsule suspension maintains appropriate viscosity and stability during storage, dilution, and application, preventing stratification, sedimentation, or clumping, and guaranteeing uniform drug release.

[0046] Preferably, the thickener is composed of magnesium aluminum silicate, polyacrylamide, and bentonite in a mass ratio of 1:0.2-0.4:0.1-0.2.

[0047] By employing the above technical solutions, the layered structure of magnesium aluminum silicate can slowly swell in water, forming a thixotropic colloidal network that significantly improves the viscosity of the suspending agent and imparts good suspension properties to the system. The amide groups on the molecular chain of polyacrylamide can bind with water molecules and other components through hydrogen bonds, further enhancing the viscosity and cohesiveness of the system. Simultaneously, the long-chain structure of polyacrylamide can form bridging effects between microcapsule particles, inhibiting particle aggregation and sedimentation, and improving the long-term stability of the suspending agent. Bentonite has strong water absorption and swelling properties; the colloid formed after absorbing water can fill the network structure of magnesium aluminum silicate and polyacrylamide, strengthening the overall structural strength of the system. At the same time, the layered structure of bentonite can adsorb some free water, reducing the migration space of microcapsule particles and further inhibiting sedimentation.

[0048] When combined, magnesium aluminum silicate provides basic thixotropic properties and a suspension framework, polyacrylamide enhances cohesiveness and particle stability through polymer chains, and bentonite helps to strengthen the structure and improve anti-interference ability. Together, they endow the microcapsule suspension with suitable viscosity, good thixotropy, and long-term storage stability, ensuring that the formulation remains uniformly dispersed during transportation, storage, and application, and guaranteeing the effective exertion of the drug efficacy.

[0049] In summary, this application has the following beneficial effects:

[0050] 1. The lambda-cyhalothrin in this application has contact and stomach poison effects, and is highly effective against lepidopteran and coleopteran pests such as aphids, cabbage caterpillars, and cotton bollworms. However, its residual effect is short-lived and it is prone to developing resistance. Thiamethoxam has systemic, contact, and stomach poison effects, and is particularly effective against piercing-sucking pests and underground pests. It has a longer residual effect, and when combined with pyrethroid pesticides, it can complement the insecticidal spectrum and delay the development of resistance.

[0051] 2. In this application, wall material one and wall material two form the microcapsule shell, controlling the slow release of the active ingredient and prolonging the duration of effect. The protective colloid helps stabilize the capsule wall structure, preventing the microcapsules from rupturing or aggregating during preparation or storage.

[0052] 3. In this application, dispersant one and dispersant two prevent microcapsule particle aggregation and maintain suspension stability. Thickener one and thickener two adjust the viscosity of the suspension, prevent microcapsule sedimentation, and improve pouring and spraying performance. Detailed Implementation

[0053] The present application will be further described in detail below with reference to the embodiments.

[0054] The raw materials used in the examples and comparative examples are all commercially available.

[0055] Preparation Example 1-1

[0056] The preparation method of the gelatin complex includes the following steps:

[0057] 0.3 kg of acryloylglycine was dispersed in 2 L of 0.1 M HCl solution, 0.4 kg of nano-silica was added, and the mixture was stirred at 50 °C for 1 h. The solution was then neutralized with NaOH to pH 7.0 to obtain the active monomer solution.

[0058] 1 kg of gelatin was dispersed in 10 L of 0.1 M phosphate buffer solution, and 0.1 kg of methacrylic anhydride was added. The mixture was reacted at 40 °C for 1.5 h to obtain mixture one.

[0059] Under light-protected conditions, an active monomer solution, 0.2 kg of hydroxyethyl methacrylate, and 0.005 kg of photoinitiator 1173 (2-hydroxy-2-methyl-1-phenyl-1-propanone) were added to mixture one, and crosslinking was carried out under ultraviolet light irradiation to obtain mixture two. The mixture was washed with water, dried, and ground to obtain a gelatin complex.

[0060] The ultraviolet light intensity was 4500 μW / cm², and the crosslinking time was 160 s.

[0061] Preparation Examples 1-2

[0062] The difference from Preparation Example 1-1 is that no nano-silica is added.

[0063] Preparation Examples 1-3

[0064] The difference from Preparation Example 1-1 is that acryloylglycine is not added.

[0065] Preparation Examples 1-4

[0066] The difference from Preparation Example 1-1 is that hydroxyethyl methacrylate is not added.

[0067] Preparation Examples 1-5

[0068] The difference from Preparation Example 1-1 is that the mass ratio of acryloylglycine, nano-silica, gelatin and hydroxyethyl methacrylate is 0.4:0.5:1:0.3.

[0069] Preparation Examples 1-6

[0070] The difference from Preparation Example 1-1 is that the mass ratio of acryloylglycine, nano-silica, gelatin and hydroxyethyl methacrylate is 0.1:0.7:1:0.1.

[0071] Preparation Example 2-1

[0072] The preparation method of modified sodium lignosulfonate includes the following steps:

[0073] (1) Add 1.5 kg of sodium lignosulfonate to 15 L of water, stir at 70 °C for 40 min, add a metal-organic framework (metal-organic framework is ZIF-8, purchased from Xi'an Qiyue Biotechnology Co., Ltd.), stir at room temperature for 0.5 h, dry, and obtain a mixture;

[0074] (2) β-cyclodextrin and 0.5 kg of polyvinylpyrrolidone were dispersed in 20 L of deionized water, and the mixture from step (1) was added. The mixture was stirred at 40 °C for 0.5 h, dried, and ground to obtain modified sodium lignin sulfonate.

[0075] The mass ratio of sodium lignosulfonate, organometallic framework and β-cyclodextrin was 1:0.3:0.15.

[0076] Preparation Example 2-2

[0077] The difference from preparation example 2-1 is that no metal-organic framework is added in step (1).

[0078] Preparation Examples 2-3

[0079] The difference from Preparation Example 2-1 is that β-cyclodextrin is not added in step (2).

[0080] Preparation Examples 2-4

[0081] The difference from Preparation Example 2-1 is that the mass ratio of sodium lignosulfonate, metal-organic framework and β-cyclodextrin is 1:0.4:0.2.

[0082] Preparation Examples 2-5

[0083] The difference from Preparation Example 2-1 is that the mass ratio of sodium lignosulfonate, metal-organic framework and β-cyclodextrin is 1:0.05:0.56.

[0084] Example 1 A microcapsule suspension-suspension agent containing chlorpyrifos and thiamethoxam, comprising the following raw materials: 12% high-efficiency chlorpyrifos, 13% thiamethoxam, 9.40% solvent, 3.35% wall material one, 0.45% protective colloid, 2.23% emulsifier, 1.34% dispersant one, 0.34% wall material two, 4.00% dispersant two, 3.00% antifreeze, 0.05% thickener one, 0.50% thickener two, 0.50% preservative, and water to make up; the total weight is 1 kg.

[0085] The preparation method of the above-mentioned microcapsule suspension-suspension agent containing chlorfluazuron and thiamethoxam includes the following steps:

[0086] (1) Mix the protective colloid, emulsifier, dispersant 1 and water evenly (shear and stir evenly at 30℃ for 3000 rpm for 10 min) to obtain the aqueous phase;

[0087] (2) Stir the high-efficiency cyhalothrin, thiamethoxam and solvent (xylene) at 57°C to obtain an oil phase. Add wall material one (diphenylmethane diisocyanate) and mix with the water phase. Emulsify (8000 rpm, 5 min). Raise the temperature to 30°C. Add wall material two (ethylenediamine). Raise the temperature to 60°C and stir to solidify (500 rpm, 5 h) to obtain the primary emulsion.

[0088] (3) Add dispersant 2 (sodium lignosulfonate), antifreeze (propylene glycol), thickener 1, thickener 2, and preservative (Kason) to the primary emulsion and stir (400 rpm, 30 min) to obtain a microcapsule suspension-suspension containing chlorfluoride and thiamethoxam.

[0089] The protective colloid is a gelatin complex, and the first dispersant is modified sodium lignosulfonate.

[0090] The emulsifier is composed of calcium dodecylbenzenesulfonate, phenylethylphenol polyoxyethylene ether, and tea polyphenols in a mass ratio of 1:0.6:0.3.

[0091] Thickener 1 is composed of xanthan gum, sodium alginate, and fatty alcohol polyoxyethylene ether in a mass ratio of 1:0.7:0.1.

[0092] Thickener 2 is composed of magnesium aluminum silicate, polyacrylamide, and bentonite in a mass ratio of 1:0.2:0.2.

[0093] The gelatin complex was prepared using Preparation Example 1-1; the modified sodium lignin sulfonate was prepared using Preparation Example 2-1.

[0094] Example 2: A microcapsule suspension-suspension agent containing chlorpyrifos and thiamethoxam, differing from Example 1 in that it includes the following raw materials: 11% high-efficiency chlorpyrifos, 14% thiamethoxam, 9.20% solvent, 3.25% wall material one, 0.35% protective colloid, 2.13% emulsifier, 1.45% dispersant one, 0.24% wall material two, 3.90% dispersant two, 2.92% antifreeze, 0.03% thickener one, 0.45% thickener two, 0.46% preservative, and water to make up the difference.

[0095] The emulsifier is composed of calcium dodecylbenzenesulfonate, phenylethylphenol polyoxyethylene ether, and tea polyphenols in a mass ratio of 1:0.7:0.2.

[0096] Thickener 1 is composed of xanthan gum, sodium alginate, and fatty alcohol polyoxyethylene ether in a mass ratio of 1:0.6:0.2.

[0097] Thickener 2 is composed of magnesium aluminum silicate, polyacrylamide, and bentonite in a mass ratio of 1:0.4:0.1.

[0098] Example 3: A microcapsule suspension-suspension agent containing chlorpyrifos and thiamethoxam, differing from Example 1 in that it includes the following raw materials: 13% high-efficiency chlorpyrifos, 12% thiamethoxam, 9.60% solvent, 3.45% wall material one, 0.50% protective colloid, 2.33% emulsifier, 1.24% dispersant one, 0.45% wall material two, 4.10% dispersant two, 3.12% antifreeze, 0.07% thickener one, 0.55% thickener two, 0.52% preservative, and water to make up the difference.

[0099] Example 4: A microcapsule suspension-suspension agent containing chlorine and thiamethoxam, which differs from Example 1 in that the emulsifier is composed of calcium dodecylbenzenesulfonate, phenethylphenol polyoxyethylene ether, and tea polyphenols in a mass ratio of 1:0.3:0.7.

[0100] Example 5: A microcapsule suspension-suspension agent containing chlorfluoride and thiamethoxam, which differs from Example 1 in that the thickener is composed of xanthan gum, sodium alginate, and fatty alcohol polyoxyethylene ether in a mass ratio of 1:0.2:0.4.

[0101] Example 6: A microcapsule suspension-suspension agent containing chlorfluoride and thiamethoxam, which differs from Example 1 in that the thickener 2 is composed of magnesium aluminum silicate, polyacrylamide, and bentonite in a mass ratio of 1:0.1:0.5.

[0102] Example 7 A microcapsule suspension-suspension agent containing chlorfluazuron and thiamethoxam, which differs from Example 1 in that the gelatin complex is prepared using Preparation Examples 1-2.

[0103] Example 8 A microcapsule suspension-suspension agent containing chlorfluoride and thiamethoxam, which differs from Example 1 in that the gelatin complex is prepared using Preparation Examples 1-3.

[0104] Example 9 A microcapsule suspension-suspension agent containing chlorfluazuron and thiamethoxam, which differs from Example 1 in that the gelatin complex is prepared using Preparation Examples 1-4.

[0105] Example 10 A microcapsule suspension-suspension agent containing chlorfluazuron and thiamethoxam, which differs from Example 1 in that the gelatin complex is prepared using Preparation Examples 1-5.

[0106] Example 11 A microcapsule suspension-suspension agent containing chlorfluoride and thiamethoxam, which differs from Example 1 in that the gelatin complex is prepared using Preparation Examples 1-6.

[0107] Example 12 A microcapsule suspension-suspension agent containing chlorfluoride and thiamethoxam, which differs from Example 1 in that the modified sodium lignin sulfonate is prepared using Preparation Example 2-2.

[0108] Example 13 A microcapsule suspension-suspension agent containing chlorfluoride and thiamethoxam, which differs from Example 1 in that the modified sodium lignin sulfonate is prepared using Preparation Examples 2-3.

[0109] Example 14 A microcapsule suspension-suspension agent containing chlorfluoride and thiamethoxam, which differs from Example 1 in that the modified sodium lignin sulfonate is prepared using Preparation Examples 2-4.

[0110] Example 15 A microcapsule suspension-suspension agent containing chlorfluoride and thiamethoxam, which differs from Example 1 in that the modified sodium lignin sulfonate is prepared using Preparation Examples 2-5.

[0111] Example 16 A microcapsule suspension-suspension agent containing chlorfluazuron and thiamethoxam, which differs from Example 1 in that the protective colloid is gelatin.

[0112] Comparative Example 1

[0113] A microcapsule suspension-suspension agent containing chlorfluazuron and thiamethoxam, which differs from Example 1 in that it does not contain dispersant 1.

[0114] The performance of the microcapsule suspensions containing chlor-fluorine and thiamethoxam prepared in Examples 1-16 and Comparative Example 1 was tested.

[0115] Experimental crop: wheat, variety Longzhong 6;

[0116] Target pests: mainly wheat aphid and wheat forked aphid;

[0117] Application method and water usage: Use a uniform spraying method to spray the entire plant.

[0118] The experiment consisted of 20 treatments (the products of Examples 1-16, Comparative Example 1, and Comparative Examples 2-4), with each treatment replicated 4 times, and each region approximately 30m². 2 Comparative Example 2 was 2.5% high-efficiency cyhalothrin microemulsion, purchased from Adama Huifeng (Jiangsu) Co., Ltd.; Comparative Example 3 was 50% thiamethoxam water-dispersible granules, purchased from Jinan Lvba Pesticide Co., Ltd.; and Comparative Example 4 was a water control.

[0119] The dosage of the formulation is 5.00 mL / mu, which means the effective ingredient dosage is between 18.75 g ai / hm². The water consumption is 50L per mu, and the whole plant is sprayed evenly once.

[0120] The survey method employed a five-point sampling approach, randomly selecting 10 plants from each area. Insect population density was assessed before application and at 1, 3, and 7 days after application. Data were recorded, and the insect population reduction rate and corrected efficacy were calculated. The formulas for calculating the insect population reduction rate and efficacy are as follows:

[0121] Insect population reduction rate = (number of live insects before application - number of live insects after application) / number of live insects before application × 100%;

[0122] Control effect = (Pest population reduction rate in the treated area - Pest population reduction rate in the blank control area) / (100 - Pest population reduction rate in the blank control area) * 100%;

[0123] The suspension rate test of the suspension concentrate was carried out in accordance with the specific steps in the national standard GB / T 14825-2006 "Method for Determination of Suspension Rate of Pesticides", and the test method was Method 2.

[0124] The suspension was stored in a constant temperature oven at 50±2℃ for 14 days, and then placed at room temperature for 14 days before the suspension rate was tested. The test results are shown in Table 1.

[0125] Determination of encapsulation efficiency:

[0126] The microcapsule suspensions prepared in the examples and comparative examples were weighed and dispersed in 100 mL of xylene. The mixture was shaken for 1 min, centrifuged, and the supernatant was obtained. The supernatant was then transferred to a 50 L volumetric flask and diluted to volume with anhydrous methanol. Simultaneously, an appropriate amount of anhydrous methanol was added to the precipitate after centrifugation, and the mixture was ultrasonically disrupted to ensure complete dissolution of the pesticide technical in the microcapsules in the anhydrous methanol. The volume was then diluted again with anhydrous methanol. The pesticide technical content in the supernatant and precipitate was determined using high-performance liquid chromatography (HPLC). The encapsulation efficiency was calculated using the following formula:

[0127] Encapsulation efficiency (%) = (1 - content of free active ingredient outside the capsule / total amount of active ingredient) × 100%.

[0128] Table 1 Test data for the examples and comparative examples

[0129]

[0130] Note: / indicates that it was not tested.

[0131] Table 2 Test data for the examples and comparative examples

[0132]

[0133] Note: / indicates that it was not tested.

[0134] As shown in Tables 1 and 2, the microcapsule suspensions containing chlorpyrifos and thiamethoxam prepared in Examples 1-3 of this application exhibit good insect population reduction rates, control effects, suspension rates, and encapsulation rates. Comparative Examples 2-4 are 2.5% high-efficiency chlorpyrifos microemulsion, 50% thiamethoxam water-dispersible granules, and a water control. Specifically, in Example 1, the insect population reduction rate was 82.71% and the control effect was 83.67% 1 day after application; the insect population reduction rate was 91.59% and the control effect was 92.54% 3 days after application; the insect population reduction rate was 96.82% and the control effect was 97.76% 7 days after application; and the insect population reduction rate was 90.78% and the control effect was 91.90% 10 days after application. The suspension rates before heat storage and 14 days after heat storage and transfer to room temperature were 99.9% and 99.8%, respectively, and the encapsulation rate was 95.3%. This indicates that the prepared microcapsule suspension-suspension agent containing chlorfluazuron and thiamethoxam, through scientific compounding and formulation technology optimization, takes into account efficacy, duration of effect and safety, and is suitable for the needs of green pest control in modern agriculture.

[0135] Examples 4-6 varied the mass ratios of emulsifier, thickener one, and thickener two, respectively. Tables 1 and 2 show that, compared to Examples 1-3, Examples 4-6 exhibited decreased insect population reduction rate, control efficacy, and suspension rate before and after 14 days from heat storage to room temperature. This indicates that the emulsifier provides favorable conditions for the preparation and storage of microcapsule suspensions, ensuring good dispersibility and efficacy within the formulation's shelf life. Thickener one and thickener two significantly improved its dispersibility, anti-agglomeration ability, and compatibility with other components (such as microcapsule wall materials and emulsifiers) in aqueous systems.

[0136] In the preparation methods of the gelatin complexes in Examples 7-11, nano-silica, acryloylglycine, and hydroxyethyl methacrylate were omitted, and the mass ratios of acryloylglycine, nano-silica, gelatin, and hydroxyethyl methacrylate were varied. Tables 1 and 2 show that the insect population reduction rate, control effect, suspension rate before heat storage and after 14 days of transition from heat storage to room temperature, and encapsulation rate of Examples 7-9 were all inferior to those of Examples 1-3 and Example 10. The performance of Example 11 was superior to that of Examples 7-9, but inferior to that of Examples 1-3. This indicates that acryloylglycine, nano-silica, gelatin, and hydroxyethyl methacrylate interact and undergo a cross-linking reaction to form an organic-inorganic interpenetrating network, enhancing the mechanical strength and environmental resistance of the microcapsule wall material and optimizing surface properties to maintain suspension stability.

[0137] Examples 12-15, in their preparation methods for modified sodium lignin sulfonate, do not include the addition of metal-organic frameworks or β-cyclodextrin, nor do they alter the mass ratio of sodium lignin sulfonate, metal-organic frameworks, and β-cyclodextrin. Tables 1 and 2 show that the insect population reduction rate, control effect, and suspension rate before and after 14 days of transition from heat storage to room temperature in Examples 12-13 are all inferior to those in Examples 1-3 and 14. The performance of Example 15 is superior to that of Examples 12-13, but inferior to that of Examples 1-3. This indicates that the mixture of sodium lignin sulfonate, metal-organic frameworks, and β-cyclodextrin improves the loading rate and stability of pesticide active ingredients (such as chlorfluazuron and thiamethoxam), thereby enhancing the water solubility of hydrophobic drugs and achieving controlled-release effects.

[0138] Example 16 used gelatin as the protective colloid, while Comparative Example 1 did not include dispersant 1. As shown in Tables 1 and 2, the insect population reduction rate, control effect, and suspension rate before and after 14 days of heat storage at room temperature were all worse in Example 16 and Comparative Example 1 than in Examples 1-3. This indicates that the gelatin complex prepared in this application has excellent performance. The combination of multiple components exhibits excellent film-forming ability, improving the performance of subsequent active ingredients. Dispersant 1 prevents microcapsule particle aggregation and maintains suspension stability, resulting in outstanding efficacy of subsequent active ingredients.

[0139] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A microcapsule suspension-suspension agent containing chlorfluazuron and thiamethoxam, characterized in that, By weight percentage, it includes the following raw materials: 11-13% high-efficiency cyhalothrin, 12-14% thiamethoxam, 9.20-9.60% solvent, 3.25-3.45% wall material I, 0.35-0.50% protective colloid, 2.13-2.33% emulsifier, 1.24-1.45% dispersant I, 0.24-0.45% wall material II, 3.90-4.10% dispersant II, 2.92-3.12% antifreeze, 0.03-0.07% thickener I, 0.45-0.55% thickener II, 0.46-0.52% preservative, and water to make up the difference; The protective colloid is a gelatin complex, and the preparation method of the gelatin complex includes the following steps: Acryloylglycine was dispersed in HCl solution, nano-silica was added, and the mixture was stirred at 50-55℃ for 1-1.5 h. The solution was then neutralized with NaOH to pH=7.0 to obtain the active monomer solution. Gelatin was dispersed in a phosphate buffer solution, methacrylic anhydride was added, and the mixture was reacted at 40-45°C for 1.5-2 hours to obtain mixture one. Under light-protected conditions, an active monomer solution, hydroxyethyl methacrylate and photoinitiator 1173 were added to mixture one, and crosslinking was carried out under ultraviolet light irradiation to obtain mixture two. The mixture was washed with water, dried and ground to obtain a gelatin complex. The mass ratio of acryloylglycine, nano-silica, gelatin, and hydroxyethyl methacrylate is 0.3-0.4:0.4-0.5:1:0.2-0.

3. The first dispersant is modified sodium lignosulfonate, the second dispersant is sodium lignosulfonate, and the preparation method of the modified sodium lignosulfonate includes the following steps: (1) Add sodium lignosulfonate to water, stir at 70-72℃ for 40-45 min, add metal-organic framework, continue stirring for 0.5-0.6 h, dry to obtain mixture; (2) Disperse β-cyclodextrin and polyvinylpyrrolidone in deionized water, add the mixture from step (1), stir at 40-42℃ for 0.5-0.7h, dry, grind, and obtain modified sodium lignin sulfonate. The mass ratio of sodium lignosulfonate, metal-organic framework and β-cyclodextrin is 1:0.3-0.4:0.15-0.

2.

2. The microcapsule suspension-suspension agent containing chlorfluazuron and thiamethoxam according to claim 1, characterized in that, The ingredients include: 12% high-efficiency cyhalothrin, 13% thiamethoxam, 9.40% solvent, 3.35% wall material I, 0.45% protective colloid, 2.23% emulsifier, 1.34% dispersant I, 0.34% wall material II, 4.00% dispersant II, 3.00% antifreeze, 0.05% thickener I, 0.50% thickener II, 0.50% preservative, and water to make up the difference.

3. The method for preparing a microcapsule suspension-suspension agent containing chlorfluazuron and thiamethoxam according to claim 1, characterized in that, Includes the following steps: (1) Mix the protective colloid, emulsifier, dispersant 1 and water evenly to obtain the aqueous phase; (2) Stir the high-efficiency cyhalothrin, thiamethoxam and solvent at 55-60℃ to obtain the oil phase, add wall material one, mix with the water phase, emulsify, raise the temperature to 30℃, add wall material two, raise the temperature to 60℃, stir and solidify to obtain the primary emulsion. (3) Add dispersant II, antifreeze, thickener I, thickener II, and preservative to the primary emulsion, stir, and obtain a microcapsule suspension-suspension containing chlorfluoride and thiamethoxam.

4. The method for preparing a microcapsule suspension-suspension agent containing chlorfluazuron and thiamethoxam according to claim 1, characterized in that, The emulsifier is composed of calcium dodecylbenzenesulfonate, phenylethylphenol polyoxyethylene ether, and tea polyphenols in a mass ratio of 1:0.6-0.7:0.2-0.

3.

5. The method for preparing a microcapsule suspension-suspension agent containing chlorfluazuron and thiamethoxam according to claim 1, characterized in that, The thickener is composed of xanthan gum, sodium alginate, and fatty alcohol polyoxyethylene ether in a mass ratio of 1:0.6-0.7:0.1-0.

2.

6. The method for preparing a microcapsule suspension-suspension agent containing chlorfluazuron and thiamethoxam according to claim 1, characterized in that, The thickener 2 is composed of magnesium aluminum silicate, polyacrylamide, and bentonite in a mass ratio of 1:0.2-0.4:0.1-0.2.

Images