Nanoemulsion containing pyriproxyfen and preparation method thereof

Abstract

The invention relates to the technical field of pesticide preparations, and provides a pyriproxyfen-containing nano-emulsion and a preparation method thereof, and the pyriproxyfen-containing nano-emulsion comprises pyriproxyfen, an emulsifier, a thickener, water and an organic solvent. According to the pyriproxyfen-containing nano-emulsion provided by the invention, the nonionic emulsifier with a relatively high HLB (Hydrophile-Lipophile Balance) value and the lipophilic emulsifier with a relatively low HLB value are compounded, so that a mixed adsorption layer can be formed on an oil-water interface, the interfacial tension is effectively reduced, and an oil phase and a water phase are more easily mixed to form the stable nano-emulsion; the strength of an interfacial film of emulsion drops in the nano-emulsion can be improved, so that the external factor resistance of the nano-emulsion is improved, the phenomena of layering, demulsification and the like of the nano-emulsion in the storage process are not easy to occur, and the long-term stability of the emulsion is improved; besides, release and absorption of pyriproxyfen in the nano-emulsion can be optimized, so that the nano-emulsion shows a relatively high diffusion rate, and a relatively good insecticidal effect is more easily exerted.

Description

Technical Field

[0001] The present invention relates to the technical field of nanopesticide processing, and in particular to a nanoemulsion containing pyriproxyfen and a preparation method thereof. Background Art

[0002] Nanopesticides refer to pesticide preparations whose active ingredient particles are at the nanometer level. Currently, mainstream nanopesticides refer to nanopesticides with nanoscale dispersion, mainly including microemulsions, aqueous solutions, and soluble solutions. The active ingredients in nanopesticide preparations have smaller particle sizes, higher specific surface areas, and better leaf coverage, and are a new type of pesticide preparation with good development prospects.

[0003] Pyriproxyfen is a juvenile hormone chitin synthesis inhibitor, which mainly inhibits the synthesis of chitin in pests, causing the pests to be unable to form an epidermis when molting, the eggs of the pests to be unable to hatch into larvae, and the pupae to be unable to emerge into adults, thereby killing the pests. Pyriproxyfen has a good killing effect on many pests, and has the advantages of systemic activity, high efficiency and low toxicity, long lasting effect, safety to crops, low toxicity to fish, little impact on the ecological environment, no odor, and easy use. However, pyriproxyfen has a very low solubility in water and a low melting point (45-47°C). It is generally processed into emulsifiable concentrates, water emulsions, microemulsions, soluble solutions and other dosage forms, which makes it easy to cause pollution during its use.

[0004] Emulsions in water and suspoemulsions are environmentally friendly water-based preparations and are one of the important development directions in the future. At present, due to the thermodynamic instability of emulsions in water and suspoemulsions, it is difficult to develop emulsions in water or suspoemulsions of pyriproxyfen, and there are no reports on nanoemulsions related to pyriproxyfen. Summary of the invention

[0005] The purpose of the present application is to provide a nanoemulsion containing pyriproxyfen and a preparation method thereof, aiming to solve the technical problem of poor stability of the nanoemulsion containing pyriproxyfen.

[0006] In order to achieve the above application purpose, the technical solution adopted in this application is as follows:

[0007] In a first aspect, the present application provides a pyriproxyfen-containing nanoemulsion, comprising the following components in the following parts by weight:

[0008]

[0009] Emulsifiers include nonionic emulsifiers and lipophilic emulsifiers. The HLB value of the nonionic emulsifier is ≥14, and the HLB value of the lipophilic emulsifier is ≤6.

[0010] In a second aspect, the present application provides a method for preparing a nanoemulsion containing pyriproxyfen, comprising the following steps:

[0011] Adding pyriproxyfen and an emulsifier into an organic solvent and mixing to obtain an oil phase; the emulsifier includes a nonionic emulsifier and a lipophilic emulsifier, the HLB value of the nonionic emulsifier is ≥14, and the HLB value of the lipophilic emulsifier is ≤6;

[0012] adding part of water to the oil phase to perform a first mixing process to obtain an oil-in-water emulsion;

[0013] Mix the thickener and the remaining water to obtain a mixed solution;

[0014] The mixed solution is added to the oil-in-water emulsion, and a second mixing treatment is performed to obtain a pyriproxyfen-containing nanoemulsion.

[0015] The first aspect of the present application provides a pyriproxyfen-containing nanoemulsion, comprising pyriproxyfen in specific weight portions, an emulsifier, a thickener, an organic solvent and water, wherein a nonionic emulsifier with a higher HLB value and a lipophilic emulsifier with a lower HLB value are compounded. On the one hand, the nonionic emulsifier with a higher HLB value has a stronger hydrophilicity, and the lipophilic emulsifier with a lower HLB value has a better adsorption on the non-polar oil phase, thereby forming a mixed adsorption layer on the oil-water interface, thereby effectively reducing the interfacial tension, making it easier for the oil phase and the water phase to mix to form a stable nanoemulsion; on the other hand, the lipophilic emulsifier can form a stable adsorption layer on the surface of the oil droplets to prevent the aggregation of the oil droplets, and the non-polar oil phase can be formed. Ionic emulsifiers can enhance the adaptability and stability of nanoemulsions. The combination of the two can increase the strength of the interfacial film of the emulsion droplets in the nanoemulsion, thereby improving its ability to resist external factors (such as temperature changes, mechanical vibrations, etc.). In this way, the nanoemulsion is not prone to stratification, demulsification, etc. during storage, thereby improving the long-term stability of the nanoemulsion. On the other hand, the combination of nonionic emulsifiers and lipophilic emulsifiers can make the oil phase more evenly dispersed in the aqueous phase, forming nanoemulsion droplets with smaller particle size and more uniform distribution, thereby optimizing the release and absorption of pyriproxyfen in the nanoemulsion, so that the nanoemulsion exhibits a higher diffusion rate and is more likely to exert a better insecticidal effect.

[0016] The preparation method of the nanoemulsion containing pyriproxyfen provided in the second aspect of the present application is to mix the raw materials of each component according to the components and proportions contained in the nanoemulsion containing pyriproxyfen in the present application, so that each raw material component can be evenly dispersed and fully emulsified to obtain a nanoemulsion with good stability and high diffusion rate. In addition, the preparation method of the nanoemulsion containing pyriproxyfen in the present application has simple process conditions, is reliable and controllable, is more conducive to improving the stability of the nanoemulsion containing pyriproxyfen, has high efficiency, and is suitable for industrial application and promotion. DETAILED DESCRIPTION

[0017] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0018] In this application, the term "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0019] In this application, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively.

[0020] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0021] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0022] The weight of the relevant components mentioned in the embodiment description of the present application can not only refer to the specific content of each component, but also represent the proportional relationship between the weights of the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the embodiment description of the present application, it is within the scope disclosed in the embodiment description of the present application. Specifically, the mass described in the embodiment description of the present application can be a mass unit known in the chemical industry such as μg, mg, g, kg, etc.

[0023] The terms "first" and "second" are used only for descriptive purposes to distinguish objects such as substances from each other, and should not be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. For example, without departing from the scope of the embodiments of the present application, the first XX may also be referred to as the second XX, and similarly, the second XX may also be referred to as the first XX. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0024] In the embodiments of the present application, the term "nonionic emulsifier" refers to a type of surfactant that does not ionize in aqueous solution, and its molecular structure is usually composed of two parts: a hydrophilic group and a hydrophobic group. The hydrophilic group is generally a segment containing multiple polar groups such as hydroxyl groups (-OH) and ether bonds (-O-), which can form hydrogen bonds with water molecules, thereby showing hydrophilicity; the hydrophobic group is mostly a long-chain hydrocarbon group, such as an alkyl group, which is hydrophobic.

[0025] In the present application, the term "lipophilic emulsifier" refers to an emulsifier in which the lipophilic group (usually a long-chain alkyl group) is dominant in the molecular structure. In the molecular structure of this type of emulsifier, the hydrophobic part (usually a long-chain hydrocarbon group, etc.) accounts for a large proportion of the entire molecule, while the hydrophilic part is relatively small, and this structure makes them interact more strongly with oil.

[0026] In the examples of the present application, the term "HLB" is the abbreviation of Hydrophile-Lipophile Balance, which means the hydrophilic-lipophilic balance value, and is generally used to describe the relative strength of the hydrophilicity and lipophilicity of emulsifier molecules.

[0027] In the embodiments of the present application, "D90" is the abbreviation of "D90 particle size" or "90th percentile particle diameter", which means that in particle size analysis, particles are statistically distributed according to particle size, and D90 means that in this distribution, 90% of the particles have a particle size smaller than this value.

[0028] The first aspect of the embodiment of the present application provides a pyriproxyfen-containing nanoemulsion, comprising the following components in the following parts by weight:

[0029]

[0030] Emulsifiers include nonionic emulsifiers and lipophilic emulsifiers. The HLB value of the nonionic emulsifier is ≥14, and the HLB value of the lipophilic emulsifier is ≤6.

[0031] In the technical solution of the present application, the HLB value of the nonionic emulsifier is ≥ 14. As an example, the HLB value of the nonionic emulsifier can be a typical but non-limiting value such as 14, 15, 16, 17, 18, 19, 20, etc. The nonionic emulsifier has a high HLB value, which means that the nonionic emulsifier is extremely hydrophilic and can not only quickly form a stable emulsion layer at the oil-water interface, but also form a strong interfacial film in the nanoemulsion, effectively preventing the aggregation and merging of oil droplets, which helps to improve the stability of the nanoemulsion and reduce the problems of stratification, demulsification, crystallization, flocculation, etc. of the nanoemulsion during storage.

[0032] In the technical solution of the application, the HLB value of the lipophilic emulsifier is ≤6. As an example, the HLB value of the lipophilic emulsifier can be a typical but non-limiting value such as 2, 3, 4, 5, 6, etc. The lipophilic emulsifier has a lower HLB value, which means that the lipophilic emulsifier has a higher affinity for the oil phase and can form a stable interfacial film at the oil-water interface. Due to its lipophilic properties, it can be well combined with the oil, effectively preventing the aggregation and merging of droplets, thereby increasing the stability of the nanoemulsion.

[0033] The embodiment of the present application comprises specific weight portions of pyriproxyfen, an emulsifier, a thickener, an organic solvent and water, wherein a nonionic emulsifier with a higher HLB value is compounded with a lipophilic emulsifier with a lower HLB value. On the one hand, the nonionic emulsifier with a higher HLB value has a stronger hydrophilicity, and the lipophilic emulsifier with a lower HLB value has a higher lipophilicity, thereby forming a mixed adsorption layer on the oil-water interface, thereby effectively reducing the interfacial tension and making it easier for the oil phase and the water phase to mix to form a stable nanoemulsion; on the other hand, the lipophilic emulsifier can form a stable adsorption layer on the surface of the oil droplets to prevent the aggregation of the oil droplets, and the nonionic emulsifier can Enhance the adaptability and stability of the nanoemulsion. The combination of the two can increase the strength of the interfacial film of the emulsion droplets in the nanoemulsion, thereby improving its ability to resist external factors (such as temperature changes, mechanical vibrations, etc.). In this way, the nanoemulsion is not prone to stratification, demulsification, etc. during storage, thereby improving the long-term stability of the emulsion. On the other hand, the combination of nonionic emulsifiers and lipophilic emulsifiers can make the oil phase more evenly dispersed in the aqueous phase, forming nanoemulsion droplets with smaller particle size and more uniform distribution, thereby optimizing the release and absorption of pyriproxyfen in the nanoemulsion. In this way, the nanoemulsion exhibits a higher diffusion rate and is more likely to exert a better insecticidal effect.

[0034] For example, the mass fraction of pyriproxyfen can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, 20 parts and other typical but non-limiting values.

[0035] For example, the mass fraction of the emulsifier can be 5 parts, 7 parts, 9 parts, 10 parts, 12 parts, 14 parts, 16 parts, 18 parts, 19 parts and other typical but non-limiting values.

[0036] For example, the mass fraction of the thickener may be 0.1 parts, 0.5 parts, 1 parts, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, etc., which are typical but non-limiting values.

[0037] For example, the mass fraction of water may be 10 parts, 20 parts, 30 parts, 40 parts, 50 parts, 60 parts, 70 parts, etc., which are typical but non-limiting values.

[0038] For example, the mass fraction of the organic solvent may be 5 parts, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, etc., which are typical but non-limiting values.

[0039] In some embodiments, the HLB value of the nonionic emulsifier is 14 to 17. For example, the HLB value of the nonionic emulsifier can be 14, 15, 16, 17, and other typical but non-limiting values.

[0040] By controlling the HLB value of the nonionic emulsifier within the above range, on the one hand, it has a strong hydrophilicity and can fully combine with the water phase and wrap the oil phase, so that the oil droplets are evenly dispersed in the water phase, and aggregation and stratification are not easy to occur, thereby effectively improving the stability of the nanoemulsion; on the other hand, it has a high dispersibility in water and can be quickly dispersed in the water phase to form a uniform emulsion, providing convenience for the subsequent emulsification process, which is conducive to the mixing of the components to form a uniform system, thereby helping to improve the stability of the nanoemulsion.

[0041] In some embodiments, the HLB value of the lipophilic emulsifier is 4 to 6. Exemplarily, the HLB value of the lipophilic emulsifier can be 4, 5, 6, etc., which are typical but non-limiting values.

[0042] Controlling the HLB value of the lipophilic emulsifier within the above range can not only reduce the interfacial tension between the oil phase and the water phase, but also make the oil phase and the water phase easier to mix and emulsify, thereby obtaining a stable nanoemulsion at a higher emulsification rate.

[0043] In some embodiments, the mass ratio of the nonionic emulsifier to the lipophilic emulsifier is 1.5: 1-6: 1. Exemplarily, the mass ratio of the nonionic emulsifier to the lipophilic emulsifier can be 1.5: 1, 2: 1, 3: 1, 4: 1, 5: 1, 6: 1 and other typical but non-limiting values.

[0044] The mass ratio of the nonionic emulsifier to the lipophilic emulsifier is controlled within the above range. On the one hand, the nonionic emulsifier can form a relatively tight and stable interfacial film at the water-oil interface, and the lipophilic emulsifier can improve the anchoring effect on the oil phase. The synergistic effect of the two enables the emulsion droplets in the nanoemulsion to exist in a more stable form; on the other hand, the lipophilic emulsifier helps to disperse the oil phase, while the nonionic emulsifier helps to combine the water phase. In this way, the combination of the two can optimize the emulsification process, make the oil-water mixing more uniform, and improve the emulsification efficiency.

[0045] In some embodiments, the nonionic emulsifier includes at least one of isomeric alcohol ethers, fatty alcohol polyoxyethylene ethers, castor oil polyoxyethylene ethers, styrylphenyl polyoxyethylene ethers, and styrene phenol formaldehyde resin polyoxyethylene ethers.

[0046] These nonionic emulsifiers can have good emulsification stability in a wide temperature range, are not easy to decompose or lose emulsification ability, so that the nanoemulsion is not easy to stratify or demulsify under high temperature conditions, low temperature conditions or storage processes. In addition, these nonionic emulsifiers have many hydrophilic groups and can be more firmly adsorbed on the surface of the oil phase, making the oil phase more easily dispersed in the water phase, and can better improve the stability and suspension rate of the emulsion droplets in the nanoemulsion, reduce the loss of the liquid medicine, and enable the nanoemulsion to better penetrate into the crop surface, thereby improving its control effect.

[0047] In some embodiments, the lipophilic emulsifier includes at least one of dioctyl sulfosuccinate, sorbitan fatty acid esters, and Atlox 4916.

[0048] As an example, sorbitan fatty acid esters include, but are not limited to, sorbitan monostearate (HLB value of about 4.7), sorbitan tristearate (HLB value of about 2.1), sorbitan monooleate (HLB value of about 4.3), and sorbitan trioleate (HLB value of about 1.8).

[0049] The non-polar groups of these lipophilic emulsifiers can be firmly adsorbed on the surface of the oil phase, forming a relatively tight interfacial film on the water-oil interface, enhancing the strength of the interfacial film, thereby forming a stable emulsified system, making it difficult for the nanoemulsion to break and aggregate. Moreover, these lipophilic emulsifiers remain relatively stable within a certain temperature range, making it difficult for the nanoemulsion to stratify under high temperature conditions, low temperature conditions or during storage, which plays a positive role in the stability of the nanoemulsion.

[0050] In some embodiments, the above-mentioned pyriproxyfen-containing nanoemulsion further includes the following components:

[0051]

[0052] The nanoemulsion containing pyriproxyfen also includes a second active ingredient, a wetting agent, a dispersant, an antifreeze agent and a defoaming agent in specific weight portions, wherein the second active ingredient can play a synergistic role with pyriproxyfen to enhance the insecticidal effect of the nanoemulsion or broaden the scope of application; the wetting agent makes it easier for the nanoemulsion to spread on a solid surface, thereby improving the coverage ability and uniformity of the nanoemulsion on the surface of an application medium such as plant leaves, and improving the insecticidal effect; the dispersant can prevent the mutual aggregation between suspended particles and nanoemulsion droplets, thereby improving the uniformity and stability of the nanoemulsion, and making the nanoemulsion have better storage stability; the antifreeze agent makes the nanoemulsion not easy to freeze in a low temperature environment, improves its fluidity and stability, and thus makes the nanoemulsion structure have better temperature adaptability; the defoaming agent can reduce surface tension, prevent the formation of foam or quickly defoam, thereby improving the dispersibility and application effect of the nanoemulsion.

[0053] Exemplarily, the second active ingredient can be 0 parts, 2 parts, 5 parts, 8 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, 22 parts, 25 parts, 28 parts, 30 parts and other typical but non-limiting values.

[0054] For example, the wetting agent may be 0, 0.5 parts, 1 part, 1.5 parts, 2 parts, etc., which are typical but non-limiting values.

[0055] For example, the dispersant may be 0 parts, 1 parts, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, etc., which are typical but non-limiting values.

[0056] For example, the antifreeze agent may be 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, etc., which are typical but non-limiting values.

[0057] For example, the defoaming agent may be present in typical but non-limiting values ​​such as 0 part, 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, etc.

[0058] In some embodiments, the particle size D90 of the second active ingredient is less than 800 nm.

[0059] The particle size of the second active ingredient is controlled to be less than 800 nm, so that the second active ingredient has a higher surface energy, thereby increasing the contact area between the second active ingredient and water, thereby facilitating more second active ingredients to interact with water molecules, and making the second active ingredient show higher solubility.

[0060] In some embodiments, the particle size D90 of the second active ingredient is 300 nm-600 nm. As an example, the particle size D90 of the second active ingredient can be 300 nm, 400 nm, 500 nm, 600 nm, etc., which are typical but non-limiting values.

[0061] Controlling the particle size of the second active ingredient within the above range increases the chances of collision and interaction between the second active ingredient and water molecules, and the number of particles that effectively collide with water molecules per unit time is relatively larger, so that the dissolution rate of the second active ingredient is significantly improved, and the solubility of the second active ingredient is improved to a certain extent.

[0062] In some embodiments, the second active ingredient includes at least one of flonicamid, thiamethoxam, imidacloprid, clothianidin, dinotefuran, and acetamiprid.

[0063] The mechanism of action of pyriproxyfen and the above-mentioned second active ingredient complement each other, and can prevent and control pests from multiple aspects, thereby improving the overall insecticidal effect. For example, pyriproxyfen mainly exerts its effect by inhibiting the growth and development processes of insects such as embryonic development and adult emergence, while flonicamid achieves its control effect by hindering the piercing-sucking feeding behavior of pests. Neonicotinoid insecticides such as thiamethoxam, clothianidin, and imidacloprid mainly act on the nervous system of insects, interfering with the conduction of neural signals. Multiple active ingredients exert a synergistic effect, making the nanoemulsion have excellent effects.

[0064] In addition, the synergistic effect of pyriproxyfen and the above-mentioned second active ingredient can expand the control range of different pest species and effectively prevent the mixed occurrence of multiple pests.

[0065] In some embodiments, the organic solvent includes at least one of trimethylbenzene, aromatic solvent S-100, aromatic solvent S-150, aromatic solvent S-200, methyl oleate, rosin-based vegetable oil, and xylene.

[0066] On the one hand, these organic solvents can be well compatible with other ingredients in the nanoemulsion, such as emulsifiers, active ingredients, etc., to form a stable emulsified system and reduce the possibility of oil-water two-phase separation; on the other hand, they can adjust the viscosity of the nanoemulsion, giving it suitable fluidity for easy use.

[0067] In some embodiments, the dispersant and the wetting agent independently include at least one of alkylbenzene sulfonate, phosphate ester, polycarboxylate, fatty alcohol polyoxyethylene ether, lignin sulfonate, naphthalene sulfonate, and anionic nonionic surfactant.

[0068] Dispersants and wetting agents help improve the stability and suspension of the nanoemulsion, and also allow the active ingredient, such as pyriproxyfen or a second active ingredient, to spread better on the application substrate, such as the surface of a plant, to improve the insecticidal effect.

[0069] As an example, the anionic nonionic surfactant includes at least one of sorbitan fatty acid and polyoxyethylene fatty alcohol ether.

[0070] In some embodiments, the antifreeze agent includes at least one of ethylene glycol, propylene glycol, glycerol, isopropanol, n-butanol, isooctyl alcohol, hexylene glycol, and urea.

[0071] These antifreeze agents, on the one hand, can improve the effect of the interfacial film in the nanoemulsion on temperature, and are not prone to problems such as demulsification and stratification due to temperature changes. On the other hand, they can adjust the rheological properties of the nanoemulsion so that the nanoemulsion has a suitable viscosity, thereby helping to improve the stability and processing performance of the nanoemulsion during storage and use.

[0072] In some embodiments, the antifreeze agent includes one or more of ethylene glycol, propylene glycol, and glycerol.

[0073] These antifreeze agents can also interact with other components such as defoamers, wetting agents, emulsifiers, etc., which can play a positive role in the stability of the water-oil interface, enhance the strength and elasticity of the interfacial film, make the interfacial film remain relatively stable at low temperatures, and prevent the demulsification and stratification problems of the nanoemulsion.

[0074] In some embodiments, the defoamer includes an organosilane defoamer. As an example, the modified organosilane defoamer includes but is not limited to defoamer AF-3050.

[0075] These defoamers can reduce the surface tension of the liquid, thereby effectively reducing or preventing the formation of foam, and destroy the stability of the bubbles, causing the bubbles to dissipate quickly.

[0076] In some embodiments, the thickener includes at least one of white carbon, polyvinyl alcohol, sodium carboxymethyl cellulose, magnesium aluminum silicate, organic bentonite, and xanthan gum.

[0077] In some embodiments, the thickener includes at least one of polyvinyl alcohol, magnesium aluminum silicate, and xanthan gum.

[0078] These thickeners can adjust the viscosity of the system and form a three-dimensional network structure, thereby playing a positive role in the stability of the nanoemulsion droplets and delaying sedimentation; in particular, polyvinyl alcohol can increase the viscosity of the nanoemulsion and thus enhance the stability of the nanoemulsion.

[0079] In some embodiments, the pyriproxyfen-containing nanoemulsion comprises a plurality of nanoemulsion droplets, and the particle size D90 of the nanoemulsion droplets is 200nm-600nm. As an example, the particle size D90 of the nanoemulsion droplets can be 200nm, 300nm, 400nm, 500nm, 600nm, etc., which are typical but non-limiting values.

[0080] The raw materials for preparing the nanoemulsion containing pyriproxyfen include multiple components such as emulsifiers and organic solvents. The emulsifier molecules usually have two groups, hydrophilic and hydrophobic, so that the emulsifier disperses the mixed system composed of active ingredients such as pyriproxyfen and solvent into tiny droplets. The hydrophilic group of the emulsifier faces the water phase, and the hydrophobic group faces the oil phase, thereby forming a stable interfacial film on the surface of the droplets, preventing the aggregation and merging of the droplets, and forming nanoemulsion droplets.

[0081] The particle size D90 of the nanoemulsion droplets is controlled within the above range. On the one hand, within this particle size range, the nanoemulsion droplets are relatively less affected by gravity, which plays a positive role in improving the stability of the nanoemulsion and is less likely to cause stratification problems. On the other hand, it is beneficial to control the release rate of active ingredients such as pyriproxyfen, thereby improving its use efficiency and insecticidal effect.

[0082] The second aspect of the embodiment of the present application provides a method for preparing a nanoemulsion containing pyriproxyfen, comprising the following steps:

[0083] Step S10, adding pyriproxyfen and an emulsifier to an organic solvent and mixing to obtain an oil phase; the emulsifier includes a nonionic emulsifier and a lipophilic emulsifier, the HLB value of the nonionic emulsifier is ≥14, and the HLB value of the lipophilic emulsifier is ≤6;

[0084] Step S20, adding part of the water to the oil phase, performing a first mixing process, and obtaining an oil-in-water emulsion;

[0085] Step S30, mixing the thickener and the remaining water to obtain a mixed solution;

[0086] Step S40, adding the mixed solution into the oil-in-water emulsion, performing a second mixing treatment, and obtaining a pyriproxyfen-containing nanoemulsion.

[0087] The preparation method of the nanoemulsion containing pyriproxyfen provided in the second aspect of the embodiment of the present application is to mix the raw materials of each component according to the components and proportions contained in the nanoemulsion containing pyriproxyfen in the present application, so that each raw material component can be evenly dispersed and fully emulsified to obtain a nanoemulsion with good stability and high diffusion rate. In addition, the preparation method of the nanoemulsion containing pyriproxyfen in the present application has simple process conditions, is reliable and controllable, is more conducive to improving the stability of the nanoemulsion containing pyriproxyfen, has high efficiency, and is suitable for industrial application and promotion.

[0088] According to the nanoemulsion containing pyriproxyfen, the raw materials are provided, and the addition amount and type of each raw material are selected as above, which will not be repeated here.

[0089] In some embodiments, in step S20, the conditions of the first mixing process include: a rotation speed of 10000 rpm-20000 rpm, and a time of 10 min-50 min. For example, the rotation speed can be 10000 rpm, 11000 rpm, 13000 rpm, 15000 rpm, 18000 rpm, 20000 rpm, etc., which are typical but non-limiting values; and the time can be 10 min, 15 min, 20 min, 30 min, 40 min, 50 min, etc., which are typical but non-limiting values.

[0090] The conditions of the first mixing treatment are controlled within the above range so that the emulsifier can fully exert its emulsification effect, the droplet size distribution is concentrated and uniform, a stable water-in-oil emulsion is formed, and problems such as particle sedimentation and stratification are not likely to occur.

[0091] In some embodiments, in step S30, the specific steps of mixing the thickener and the remaining water include:

[0092] The second active ingredient, wetting agent, dispersant, antifreeze agent, defoaming agent and thickener are added to the remaining water and mixed to obtain a mixed solution.

[0093] In some embodiments, in step S30, before mixing the second active ingredient, wetting agent, dispersant, defoaming agent with antifreeze agent and thickener, the second active ingredient, wetting agent, dispersant and defoaming agent need to be mixed and ground until the particle size D90 of the second active ingredient is less than 800 nm.

[0094] As an example, the grinding process may be performed using a sand grinder.

[0095] Controlling the particle size D90 of the second active ingredient within the above range can effectively increase its saturated solubility in water, thereby facilitating uniform and stable distribution of the second active ingredient in the nanoemulsion.

[0096] In some embodiments, in step S40, the conditions of the second mixing process include: a rotation speed of 1000 rpm-2000 rpm, and a time of 10 min-20 min. For example, the rotation speed can be 1000 rpm, 1200 rpm, 1500 rpm, 1800 rpm, 2000 rpm, and other typical non-limiting values; the time can be 10 min, 12 min, 15 min, 16 min, 18 min, 20 min, and other typical non-limiting values.

[0097] The conditions of the second mixing treatment are controlled within the above range, so that the nanoemulsion system is relatively stable and is not prone to stratification.

[0098] The following describes the invention in conjunction with specific embodiments.

[0099] Example 1

[0100] This embodiment provides a pyriproxyfen-containing nanoemulsion and a preparation method thereof.

[0101] A nanoemulsion containing pyriproxyfen, the ingredients of which are shown in Table 1 below.

[0102] Table 1

[0103]

[0104] In Table 1, the mass ratio of the nonionic emulsifier to the lipophilic emulsifier is 14:5, the nonionic emulsifier includes isomeric alcohol ether and styrene phenol formaldehyde resin polyoxyethylene ether in a mass ratio of 4:10, and the lipophilic emulsifier includes sorbitan tristearate.

[0105] A method for preparing a pyriproxyfen nanoemulsion comprises the following steps:

[0106] Step 1, pyriproxyfen and an organic solvent are mixed, stirred at 800 rpm, and then an emulsifier is added and stirred at 800 rpm to obtain an oil phase;

[0107] Step 2: adding water to the oil phase under high-speed shearing conditions of 15000 rpm and continuously shearing for 20 minutes to obtain an oil-in-water emulsion;

[0108] Step 3: adding a thickener, a defoaming agent and an antifreeze agent to the oil-in-water emulsion, stirring at 1000 rpm for 10 minutes, to obtain a nanoemulsion containing pyriproxyfen.

[0109] Example 2

[0110] This embodiment provides a pyriproxyfen-containing nanoemulsion and a preparation method thereof.

[0111] A nanoemulsion containing pyriproxyfen, the ingredients of which are shown in Table 2 below.

[0112] Table 2

[0113]

[0114] In Table 2, the mass ratio of the nonionic emulsifier to the lipophilic emulsifier is 12:4, the nonionic emulsifier includes isomeric alcohol ether and styrene phenol formaldehyde resin polyoxyethylene ether in a mass ratio of 4:8, and the lipophilic emulsifier includes Atlox 4916.

[0115] A method for preparing a pyriproxyfen nanoemulsion comprises the following steps:

[0116] Step 1, pyriproxyfen and an organic solvent are mixed, stirred at 800 rpm, and then an emulsifier is added and stirred at 800 rpm to obtain an oil phase;

[0117] Step 2, under the condition of high-speed shearing at 15000 rpm, 80 wt% of water was added to the oil phase and shearing was continued for 20 minutes to obtain an oil-in-water emulsion;

[0118] Step 3, mixing the thickener, defoamer, antifreeze agent and remaining water to obtain a mixed solution;

[0119] Step 4: adding the mixed solution into the oil-in-water emulsion, stirring at 1000 rpm for 15 min to obtain a pyriproxyfen-containing nanoemulsion.

[0120] Example 3

[0121] This embodiment provides a pyriproxyfen-containing nanoemulsion and a preparation method thereof.

[0122] A nanoemulsion containing pyriproxyfen, the ingredients of which are shown in Table 3 below.

[0123] Table 3

[0124]

[0125] In Table 3, the mass ratio of the nonionic emulsifier to the lipophilic emulsifier is 7:2, the nonionic emulsifier includes isomeric alcohol ether and styrene phenol formaldehyde resin polyoxyethylene ether in a mass ratio of 3:4, and the lipophilic emulsifier includes Atlox 4916; the mass ratio of magnesium aluminum silicate to xanthan gum is 1:0.15, and the mass ratio of lignin sulfonate to phosphate is 1:3.

[0126] A method for preparing a pyriproxyfen nanoemulsion comprises the following steps:

[0127] Step 1, pyriproxyfen and an organic solvent are mixed, stirred at 800 rpm, and then an emulsifier is added and stirred at 800 rpm to obtain an oil phase;

[0128] Step 2, under the condition of high-speed shearing at 15000 rpm, 50 wt% of water was added to the oil phase and shearing was continued for 20 minutes to obtain an oil-in-water emulsion;

[0129] Step 3, mixing the second active ingredient, the dispersant, the antifreeze agent, the thickener, the defoamer and the remaining water, and grinding them in a sand mill until the particle size D90 of the second active ingredient is less than 800 nm, to obtain a mixed solution, i.e., the flonicamid nano suspension;

[0130] Step 4: adding the mixed solution into the oil-in-water emulsion, stirring at 1000 rpm for 15 min to obtain a pyriproxyfen-containing nanoemulsion.

[0131] Example 4

[0132] This embodiment provides a pyriproxyfen-containing nanoemulsion and a preparation method thereof.

[0133] A nanoemulsion containing pyriproxyfen is different from Example 3 in terms of raw material ingredients and weight fractions, as shown in Table 4 below.

[0134] Table 4

[0135]

[0136] In Table 4, the mass ratio of the nonionic emulsifier to the lipophilic emulsifier is 4:2, the nonionic emulsifier includes isomeric alcohol ether and styrene phenol formaldehyde resin polyoxyethylene ether in a mass ratio of 1:3, and the lipophilic emulsifier includes sorbitan tristearate; the mass ratio of magnesium aluminum silicate to xanthan gum is 8:1.

[0137] Example 5

[0138] This embodiment provides a pyriproxyfen-containing nanoemulsion and a preparation method thereof.

[0139] A nanoemulsion containing pyriproxyfen, which differs from Example 3 in terms of raw material ingredients and weight fractions, as shown in Table 5 below.

[0140] Table 5

[0141]

[0142]

[0143] In Table 5, the mass ratio of nonionic emulsifier to lipophilic emulsifier is 4.5:2, the nonionic emulsifier includes isomeric alcohol ether and styrene phenol formaldehyde resin polyoxyethylene ether in a mass ratio of 2:2.5, and the lipophilic emulsifier includes Atlox 4916; the mass ratio of magnesium aluminum silicate to xanthan gum is 10:1; and the mass ratio of polycarboxylate to lignin sulfonate is 3:1.

[0144] Example 6

[0145] This embodiment provides a pyriproxyfen-containing nanoemulsion and a preparation method thereof.

[0146] A nanoemulsion containing pyriproxyfen, which differs from Example 3 in terms of raw material ingredients and weight fractions, as shown in Table 6 below.

[0147] Table 6

[0148]

[0149] In Table 6, the mass ratio of nonionic emulsifier to lipophilic emulsifier is 6:1, the nonionic emulsifier includes isomeric alcohol ether and styrene phenol formaldehyde resin polyoxyethylene ether in a mass ratio of 1:5, and the lipophilic emulsifier includes Atlox 4916; the mass ratio of magnesium aluminum silicate to xanthan gum is 10:1; the mass ratio of fatty alcohol polyoxyethylene ether to alkylbenzene sulfonate is 3:1.

[0150] Example 7

[0151] This embodiment provides a pyriproxyfen-containing nanoemulsion and a preparation method thereof.

[0152] A nanoemulsion containing pyriproxyfen, which differs from Example 3 in terms of raw material ingredients and weight fractions, as shown in Table 7 below.

[0153] Table 7

[0154]

[0155] In Table 7, the mass ratio of nonionic emulsifier to lipophilic emulsifier is 7:3, the nonionic emulsifier includes isomeric alcohol ether and styrene phenol formaldehyde resin polyoxyethylene ether in a mass ratio of 2:5, and the lipophilic emulsifier includes Atlox 4916; the mass ratio of magnesium aluminum silicate to xanthan gum is 6:1; and the mass ratio of polycarboxylate to lignin sulfonate is 3:1.

[0156] Example 8

[0157] This embodiment provides a pyriproxyfen-containing nanoemulsion and a preparation method thereof.

[0158] A nanoemulsion containing pyriproxyfen, which differs from Example 3 in terms of raw material ingredients and weight fractions, as shown in Table 8 below.

[0159] Table 8

[0160]

[0161]

[0162] In Table 8, the mass ratio of the nonionic emulsifier to the lipophilic emulsifier is 3:2, the nonionic emulsifier includes isomeric alcohol ether and styrene phenol formaldehyde resin polyoxyethylene ether in a mass ratio of 1:2, and the lipophilic emulsifier includes sorbitan tristearate; the mass ratio of magnesium aluminum silicate to xanthan gum is 4:1.

[0163] Comparative Example 1

[0164] This comparative example provides a pyriproxyfen-containing emulsion and a preparation method thereof, which is different from Example 3 in that the particle size of the second active ingredient is different, specifically:

[0165] Step 3, mixing the second active ingredient, the dispersant, the antifreeze agent, the thickener, the defoamer and the remaining water, and grinding them in a sand mill so that the particle size D90 of the second active ingredient is about 4 μm, to obtain a mixed solution, i.e., the flonicamid suspension concentrate;

[0166] Comparative Example 2

[0167] This comparative example provides a pyriproxyfen-containing emulsion and a preparation method thereof, which is different from Example 1 in that the emulsifier is different, and the emulsifier is 8% styrene phenol formaldehyde resin polyoxyethylene ether.

[0168] Performance Testing

[0169] (1) Particle size and solubility test

[0170] Particle size test method: prepare a saturated aqueous solution containing the second active ingredient, use the saturated aqueous solution as the dispersed phase, and disperse the mixed solution obtained in step 3 of Examples 3-8 in the corresponding saturated aqueous solution for particle size measurement.

[0171] Solubility test: The mixed solution obtained in step 3 of Examples 3-8 was slowly added dropwise into a beaker containing 100 g of water, stirring while adding until the solution began to become turbid. The solubility was calculated based on the weight of the added mixed solution.

[0172] The results of the particle size test and solubility test of the second active ingredient are shown in Table 9:

[0173] Table 9

[0174]

[0175]

[0176] In Table 9:

[0177] The benchmark solubility refers to the solubility of the second active ingredient when it is directly dissolved in water without any treatment.

[0178] The actual solubility refers to the solubility of the second active ingredient in water when the particle size D90 is controlled under certain conditions. For example, in Example 3, the particle size D90 of flonicamid is 728 nm, and the solubility of flonicamid in water is 9.7 g / L.

[0179] It can be clearly seen from Table 9 that by controlling the particle size D90 of the second active ingredient to be less than 800 nm, its saturated solubility in water is significantly improved.

[0180] (2) Stability test

[0181] The emulsions obtained in Examples 1-8 and Comparative Examples 1-2 were subjected to stability tests.

[0182] Hot storage test: Store at 54°C for 14 days, and then observe the appearance, suspension rate, dispersibility and particle size after storage. The results are shown in Table 10.

[0183] Frozen storage test: Store at -18°C for 7 days, and then observe the appearance, suspension rate, dispersibility and particle size after storage. The results are shown in Table 11.

[0184] Dispersion stability refers to whether the diluted solution formed by diluting the nanoemulsion 100 times with standard hard water (342 mg / L) can maintain good uniformity within a certain period of time, that is, there is no obvious stratification, precipitation, floating oil or ointment phenomenon. If these phenomena occur, it is unqualified.

[0185] Suspension rate refers to the ability of small solid particles to suspend in water within a certain period of time, calculated based on the amount of sedimentation.

[0186] The particle size D90 refers to the particle size of the nanoemulsion droplets, and the test method is to dilute the emulsion in water and reach the measurement shading required by the measuring instrument. In this application, since the second active ingredient has greater water solubility, the second active ingredient is completely dissolved in water when the shading required for measurement is reached, so the measured suspoemulsion particle size D90 is actually the particle size D90 of the nanoemulsion droplets.

[0187] Table 10

[0188]

[0189]

[0190] As can be seen from Table 10, compared with the comparative examples 1-2 in which the particle size was enlarged, water precipitation was serious, and even demulsification occurred, resulting in poor stability, the pyriproxyfen-containing nanoemulsion prepared in the present application had better stability in the hot storage test.

[0191] Table 11

[0192]

[0193] As can be seen from Table 11, compared with the comparative examples 1-2 which had problems such as increased particle size, water and oil separation, and demulsification, the pyriproxyfen-containing nanoemulsion prepared in the present application had better stability in the frozen storage test.

[0194] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A nanoemulsion containing pyriproxyfen, characterized in that: The following components are included in the following weight parts: The emulsifier comprises a nonionic emulsifier and a lipophilic emulsifier, the HLB value of the nonionic emulsifier is ≥14, and the HLB value of the lipophilic emulsifier is ≤6.

2. The pyriproxyfen-containing nanoemulsion according to claim 1, characterized in that The HLB value of the nonionic emulsifier is 14-17; and / or The HLB value of the lipophilic emulsifier is 4-6; and / or The mass ratio of the nonionic emulsifier to the lipophilic emulsifier is 1.5:1-6:

1.

3. The pyriproxyfen-containing nanoemulsion according to claim 2, characterized in that: The nonionic emulsifier comprises at least one of isomeric alcohol ethers, fatty alcohol polyoxyethylene ethers, castor oil polyoxyethylene ethers, styrylphenyl polyoxyethylene ethers and styrene phenol formaldehyde resin polyoxyethylene ethers; and / or The lipophilic emulsifier includes at least one of dioctyl sulfosuccinate, sorbitan fatty acid ester and Atlox 4916.

4. The pyriproxyfen-containing nanoemulsion according to claim 1, characterized in that Also includes the following components:

5. The pyriproxyfen-containing nanoemulsion according to claim 4, characterized in that: The particle size D90 of the second active ingredient is less than 800 nm.

6. The pyriproxyfen-containing nanoemulsion according to claim 4, characterized in that: The second active ingredient comprises at least one of flonicamid, thiamethoxam, imidacloprid, clothianidin, dinotefuran and acetamiprid; and / or The organic solvent comprises at least one of trimethylbenzene, aromatic solvent S-100, aromatic solvent S-150, aromatic solvent S-200, methyl oleate, rosin-based vegetable oil and xylene; and / or The dispersant and the wetting agent independently include at least one of alkylbenzene sulfonate, phosphate, polycarboxylate, fatty alcohol polyoxyethylene ether, lignin sulfonate, naphthalene sulfonate, anionic nonionic surfactant; and / or The antifreeze agent comprises at least one of ethylene glycol, propylene glycol, glycerol, isopropanol, n-butanol, isooctyl alcohol, hexylene glycol and urea; and / or The defoaming agent comprises an organosilane defoaming agent; and / or The thickener comprises at least one of white carbon black, polyvinyl alcohol, sodium carboxymethyl cellulose, magnesium aluminum silicate, organic bentonite and xanthan gum.

7. The pyriproxyfen-containing nanoemulsion according to any one of claims 1 to 6, characterized in that The pyriproxyfen-containing nanoemulsion comprises a plurality of nanoemulsion droplets, and the particle size D90 of the nanoemulsion droplets is 200nm-600nm.

8. A method for preparing a nanoemulsion containing pyriproxyfen, characterized in that: The following steps are involved: Adding pyriproxyfen and an emulsifier to an organic solvent and mixing to obtain an oil phase; the emulsifier comprises a nonionic emulsifier and a lipophilic emulsifier, the HLB value of the nonionic emulsifier is ≥14, and the HLB value of the lipophilic emulsifier is ≤6; adding part of water to the oil phase to perform a first mixing process to obtain an oil-in-water emulsion; Mix the thickener and the remaining water to obtain a mixed solution; The mixed solution is added to the oil-in-water emulsion, and a second mixing treatment is performed to obtain a pyriproxyfen-containing nanoemulsion.

9. The method for preparing the pyriproxyfen nanoemulsion according to claim 8, characterized in that: The specific steps of mixing the thickener and the remaining water include: The second active ingredient, a wetting agent, a dispersant, an antifreeze agent, a defoaming agent and the thickener are added to the remaining water and mixed to obtain the mixed solution.

10. The method for preparing the pyriproxyfen nanoemulsion according to claim 9, characterized in that: The conditions of the first mixing treatment include: a rotation speed of 10000 rpm-20000 rpm, a time of 10 min-50 min; and / or The conditions of the second mixing treatment include: a rotation speed of 1000 rpm-2000 rpm, and a time of 10 min-20 min.

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