Pesticide preparation containing Se-CDs, benzylaminopurine and triacontanol

Abstract

The invention relates to the technical field of pesticide preparations, and discloses a pesticide preparation containing Se-CDs, benzylaminopurine and triacontanol, the pesticide preparation is a nanometer suspending agent prepared from benzylaminopurine raw medicine, triacontanol raw medicine, a Se-CDs nanometer material and an auxiliary agent, and the particle size D90 of solid particles in the nanometer suspending agent is smaller than or equal to 800 nm; the auxiliary agent comprises a wetting dispersant, a thickening agent, a rheological agent, an anti-freezing agent, a preservative, a defoaming agent and deionized water, and the wetting dispersant is composed of an anionic-nonionic wetting dispersant SP-SC3219 and a weak cationic wetting dispersant SP-SC3275. According to the invention, the problems of large grinding particle size and long grinding time of a pesticide composition containing benzylaminopurine in the preparation and grinding process of a suspending agent and the problem of unstable fusion of Se-CDs with nano particle size and a suspending agent with micron particle size are solved, and the particle size stability and appearance stability of the preparation are improved.

Description

Technical Field

[0001] The invention relates to the technical field of pesticide preparations, and in particular to a pesticide preparation containing Se-CDs, benzylaminopurine and triacontanol. Background Art

[0002] Pesticide technical materials, except for water-soluble and volatile technical materials, generally cannot be applied directly due to lack of dispersibility. They must be prepared with appropriate pesticide adjuvants according to the properties, usage methods, and control targets of the technical materials, and processed through certain processes to form suitable forms, called pesticide preparations, to increase their dispersibility. Scientifically mixing different pesticide technical materials into compound preparations can greatly improve efficacy, reduce toxicity, and delay the development of drug resistance.

[0003] Benzylaminopurine is the first synthetic cytokinin, also known as 6-benzylaminopurine. Benzylaminopurine is a synthetic cytokinin plant growth regulator with a purine ring and has high cytokinin activity. It stimulates plant growth and development by stimulating cell division, flowering and fruit abundance. It is an inhibitor of plant respiratory kinases, which can increase the post-harvest life of green vegetables and help preserve freshness. It has poor conductivity and mainly acts on the parts of the plant that come into contact with it, which can promote cell division, lateral bud germination, and bottom seedlings. It can increase the fruit setting rate, prevent fruit cracking, and form seedless fruits.

[0004] Triacontanol is a natural long-chain plant growth regulator. Its chemical name is n-triacontanol, also known as beeswax. It is a natural, low-toxic and highly effective plant regulator purified and extracted from Chinese honey bee wax. It can promote crop growth and development, enhance crop photosynthesis, regulate nutritional balance, increase fruit setting rate and fruiting rate, improve crop quality and increase yield, and other physiological functions. If used in the early stage of crop growth, it can increase germination rate, improve seedling quality, and increase effective tillering. If used in the middle and late stages of growth, it can increase the number of flower buds, fruit setting rate and thousand-grain weight, and it is widely applicable to crops.

[0005] Compounding benzylaminopurine and triacontanol into a composition to achieve synergistic application of the two components is a common method in the current pesticide industry. Currently, 2% soluble concentrates and 10% water-dispersible granules have been registered. However, the 2% benzylaminopurine·triacontanol soluble concentrate has a low content of active ingredients, with the content of benzylaminopurine+triacontanol being 1.9%+0.1%. The solubility of benzylaminopurine and triacontanol in water is low, and a large amount of solvent is required, which is not user-friendly and environmentally friendly. The 10% benzylaminopurine·triacontanol water-dispersible granules involve air flow crushing, granulation and screening processes, which consume a lot of energy and need to be disintegrated and dispersed before use during use. Precipitation may occur and easily clog the nozzle.

[0006] For the compound composition of benzylaminopurine and triacontanol, how to increase the compound ratio of active ingredients, improve the efficacy, reduce the energy consumption of preparation, and improve the convenience of use is a problem that pesticide formulation developers need to solve. Configuring it as a suspension is a feasible method. Pesticide suspensions have good fluidity, dispersibility, adhesion, high biological activity, do not use any organic solvents, are dust-free during production, are safe for operators and users and the environment, and have low production costs. In the past decade, it has developed rapidly at home and abroad and has replaced some emulsifiable concentrates and wettable powders to become one of the most important processing dosage forms. Suspension refers to a solid pesticide that is difficult to dissolve in water and an adjuvant that is ground and dispersed to form a stable liquid-solid system with fine particles, high suspension, and flowability. The particle size D90 of the suspension is generally around 5μm, which belongs to a thermodynamically unstable multiphase dispersion system. It has the disadvantages of high energy consumption in sand grinding and easy stratification and crystallization of the product. In addition, due to the crystal structure of the original drug of benzylaminopurine, the composition containing benzylaminopurine is prone to problems of large grinding particle size and long grinding time during the grinding process of the suspension preparation, which is not conducive to the exertion of drug efficacy.

[0007] Se-CDs, the full name of which is selenium-doped carbon quantum dot nanoenzymes, is a general term for nanomaterials with activities similar to cellular antioxidant enzymes. When used as a seed soaking agent, Se-CDs can remove superoxide anions and hydroxyl radicals in vitro, and can improve the growth of plant seedlings under salt stress. However, the use of selenium-doped carbon quantum dot nanoenzymes Se-CDs alone for crop protection increases labor costs. Therefore, it can be combined with plant growth regulators for one-time application to reduce the cost of application. However, Se-CDs are spherical nanoparticles with a particle size of about 2-5nm, and the particle size D90 of ordinary suspensions is generally around 5μm. The particle size deviation between the two is huge, and there is a significant density difference. The fusion of Se-CDs with pesticide suspensions is not conducive to the stability of the preparation and the synergistic effect of the drug. Summary of the invention

[0008] In view of this, the present invention provides a pesticide preparation containing Se-CDs, benzylaminopurine and triacontanol, which solves the problems of large grinding particle size and long grinding time in the grinding process of suspension preparation of the pesticide composition containing benzylaminopurine and the unstable fusion of nano-particle Se-CDs and micron-particle suspension. Compared with the existing compound pesticide preparation containing benzylaminopurine and triacontanol, the pesticide preparation provided by the present invention not only improves the efficacy, but also improves the particle size stability and appearance stability of the preparation.

[0009] To achieve the above purpose, the present invention provides a pesticide preparation containing Se-CDs, benzylaminopurine and triacontanol, which is a nanosuspension prepared from benzylaminopurine technical, triacontanol technical, Se-CDs nanomaterial and auxiliary agents as raw materials, the D90 particle size of the solid particles in the nanosuspension is ≤800nm; the auxiliary agents include a wetting dispersant, a thickener, a rheological agent, an antifreeze agent, a preservative, a defoaming agent and deionized water, and the wetting dispersant is composed of an anionic-nonionic wetting dispersant SP-SC3219 and a weak cationic wetting dispersant SP-SC3275.

[0010] Furthermore, the percentage of the raw materials in the total weight of the nanosuspension is: 2-8% of benzylaminopurine technical, 0.2-0.4% of triacontanol technical, 1-5% of Se-CDs nanomaterial, 5-15% of wetting dispersant, 0.2-0.5% of thickener, 0.1-0.5% of rheological agent, 3-5% of antifreeze, 0.1-0.5% of preservative, 0.1-0.5% of defoaming agent, and the balance is deionized water.

[0011] Furthermore, the mass ratio of SP-SC3219 to SP-SC3275 in the wetting and dispersing agent is 1:(3.5-6).

[0012] More preferably, the mass ratio of SP-SC3219 to SP-SC3275 in the wetting and dispersing agent is 1:4.

[0013] SP-SC3219 and SP-SC3275 are wetting and dispersing agents produced by Jiangsu Qingyu Chemical Technology Co., Ltd. Their component composition information is shown in Tables 1 and 2 below.

[0014] Table 1. Composition of SP-SC3219

[0015]

[0016]

[0017] Table 2. Composition of SP-SC3275

[0018] Element content CAS Polymer carboxylic acid with special structure 40％ 62601-60-9 water 60％ 7732-18-5

[0019] Nano suspension is a suspension liquid preparation formed by dispersing the active ingredients of pesticides and solid formula components in water in the form of solid particles or microcapsules with an average particle size of nanometers using nano preparation technology. Nano suspension can solve the solubility problem of most poorly soluble drugs, improve the utilization rate of poorly soluble drugs, produce bioadhesion, improve the chemical stability of pesticides, etc. The present invention prepares the pesticide preparation containing Se-CDs, benzylaminopurine and triacontanol into a nano suspension formulation, ensuring the fusion stability of the nano material Se-CDs and the suspension.

[0020] At present, the preparation of nanosuspension is mainly carried out by grinding with nano sand mill. As the particle size becomes smaller and smaller, its energy consumption increases. The nanosuspension itself is a thermodynamically unstable system with a very small particle size and a large specific surface area, which produces a very high surface energy. The nanoparticles have a tendency to aggregate with each other to reduce the surface energy of the entire system, so they are prone to mutual aggregation. In the process of preparing nanosuspension, as the particle size of the original drug decreases, the original drug will change from a crystalline state to an amorphous state. The amorphous original drug has the characteristics of increased solubility and Ostwald ripening, which will lead to flocculation and aggregation. Due to the different densities of the dispersion medium and the particles, the directional movement of the particles under the action of gravity causes the dispersion system to separate, and finally leads to sedimentation. Therefore, the key technical issues in the preparation of nanosuspension at present are to improve the sand milling efficiency and ensure the stability of the preparation.

[0021] Wetting and dispersing agent is a surfactant with both wetting and dispersing effects, which can reduce the interfacial tension between liquid and solid, enhance the lyophilicity of pesticides, improve the mechanical grinding efficiency, and at the same time adsorb on the surface of drug particles to form charge effect or steric hindrance effect, so that the dispersion is in a stable state. The present invention selects a combination of SP-SC3219 and SP-SC3275 as the wetting and dispersing agent of the nanosuspension, wherein the alkylnaphthalene formaldehyde condensate (molecular formula: C 21 H 14 Na2O6S2), provides excellent diffusivity and protective colloid properties for the entire suspension system, and has no surface activity such as osmotic foaming; the fatty acid ether modified substance (molecular formula: C 28 H 54 O7) provides wettability for the entire system; the specially structured polymerized carboxylic acid polymer (molecular formula: CnH2nOmN) contained in SP-SC3275 provides strong electrostatic repulsion and strong steric hindrance for the entire system. Therefore, the combination of SP-SC3219 and SP-SC3275 provides excellent dispersibility and stability for the suspension system.

[0022] The present invention uses a combination of a wetting dispersant SP-SC3219 containing an alkylnaphthalene formaldehyde condensate and a fatty acid ether modifier and a polymeric carboxylic acid high molecular weight dispersant SP-SC3275 with a special structure, thereby effectively avoiding the aggregation and particle size growth of the nano suspension during the sand milling process and the storage process, improving the sand milling efficiency, and realizing the preparation of the benzylaminopurine·triacontanol nano suspension containing nano materials.

[0023] Furthermore, in some embodiments of the present invention, the thickener is selected from at least one of xanthan gum, gum arabic, methyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone and bentonite.

[0024] Furthermore, in some embodiments of the present invention, the rheological agent is selected from at least one of magnesium aluminum silicate, fumed titanium dioxide, and white carbon black.

[0025] Furthermore, in some embodiments of the present invention, the antifreeze agent is selected from at least one of ethylene glycol, propylene glycol, glycerol, polyethylene glycol, sorbitol, and urea.

[0026] Furthermore, in some embodiments of the present invention, the preservative is selected from at least one of KSG-401 and sodium benzoate.

[0027] Furthermore, in some embodiments of the present invention, the defoaming agent is selected from at least one of DF-66 and M9313.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The pesticide preparation containing Se-CDs, benzylaminopurine and triacontanol provided by the present invention solves the problems that the benzylaminopurine pesticide composition is prone to large grinding particle size and long grinding time in the grinding process of suspension preparation, and the problem that the fusion of nano-particle-sized Se-CDs and micron-particle-sized suspension is unstable. Under the conditions of hot storage for 14 days, cold storage for 7 days, normal storage for 1 month, and hot storage transferred to room temperature for 1 month, the particle size can still be kept at the nanometer level, thereby ensuring the quality stability of the nano suspension added with nano materials and improving the efficacy of the preparation. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with specific examples. It is to be understood that the following examples are merely illustrative of the present invention and should not be regarded as the entirety of the present invention or as a definition or restriction of the technical solution of the present invention. Unless otherwise specified, the constituent raw materials used in the following experiments can all be obtained through conventional commercial channels.

[0031] The term "hot storage" means that the sample is stored in a constant temperature box at 54℃±2℃ for 14 days, taken out and cooled to room temperature, and the mass fraction of active ingredients and other specified items are determined within 24 hours. The term "cold storage" means that the sample is stored in a refrigerator at -5℃±2℃ for 7 days, taken out and placed at room temperature, and the mass fraction of active ingredients and other specified items are determined within 24 hours. The term "normal storage" means that the sample is stored in a constant temperature box at 30℃±2℃, taken out and placed at room temperature after the storage time, and the mass fraction of active ingredients and other specified items are determined within 24 hours. The term "room temperature" means general temperature, generally defined as 25℃.

[0032] The basic information of the wetting and dispersing additives used in the following tests is shown in Table 3 below.

[0033] Table 3. Basic information of wetting and dispersing agents

[0034]

[0035]

[0036] The basic information of the defoamers and preservatives used in the following tests is shown in Table 4 below.

[0037] Table 4. Basic information of defoamers and preservatives

[0038]

[0039] Experiment 1: Verification of the stability of the suspension with added nanomaterial Se-CDs

[0040] 1. Preparation method

[0041] 1. The nanosuspension is prepared according to the following steps:

[0042] Step S1: dissolve all the wetting and dispersing agents in 1 / 5 of deionized water, then add all the rheological agents, defoaming agents, technical drugs and nanomaterial Se-CDs, homogenize and disperse at a speed of 10000 rpm for 5-10 minutes, grind D90 to ≤5.0 μm using a horizontal sand mill, filter, and obtain a mixed solution A;

[0043] Step S2: Grind the mixed solution A to a particle size D90 of ≤1.0 μm using a nano-scale sand mill, and filter to obtain a mixed solution B;

[0044] Step S3: Mix the thickener, antifreeze agent and preservative according to proportion and fully swell to obtain a mixed solution C;

[0045] Step S4: Add the mixed solution C and the remaining deionized water into the mixed solution B in proportion, and homogenize and disperse at a speed of 10000 rpm for 5-10 minutes to obtain the nanosuspension.

[0046] 2. Ordinary suspension concentrate is prepared according to the following steps:

[0047] Step S1: dissolve all the wetting and dispersing agent in 1 / 5 of deionized water, then add all the rheological agent, defoaming agent, and technical, homogenize and disperse at a speed of 10000 rpm for 5-10 minutes, grind D90 to ≤5.0 μm using a horizontal sand mill, filter, and obtain a mixed solution A;

[0048] Step S2: Mix the thickener, antifreeze agent and preservative according to proportion and fully swell to obtain a mixed solution B;

[0049] Step S3: Add the mixed solution B and the remaining deionized water into the mixed solution A in proportion, then add the nanomaterial Se-CDs, and homogenize and disperse at a speed of 10000 rpm for 5-10 minutes to obtain the common suspension.

[0050] 2. Verification Method

[0051] Example 1-3 Nanosuspensions were prepared according to the composition listed in Table 5 below;

[0052] Comparative Examples 1-6 Nanosuspensions were prepared according to the composition listed in Table 6 below;

[0053] Comparative Examples 7-8: Nanosuspensions were prepared according to the ingredients listed in Table 5 below;

[0054] Comparative Example 9 A common suspension concentrate was prepared according to the ingredients listed in Table 5 below.

[0055] Table 5. Composition of Examples 1-3 and Comparative Examples 7-9

[0056]

[0057] Table 6. Composition of ingredients of comparative examples 1-6

[0058]

[0059] Stability study: The nanosuspensions obtained in the above Examples 1-3 and Comparative Examples 1-8, and the suspension obtained in Comparative Example 9 were respectively taken, and the particle size D90 and water precipitation rate were tested at 0 day, after 14 days of hot storage, after 7 days of cold storage, after 1 month of normal storage, and after 1 month of hot storage to room temperature. The results are shown in Tables 7 and 8 below.

[0060] Table 7. Stability test results of Examples 1-3 and Comparative Examples 7-9

[0061]

[0062]

[0063] Table 8. Stability test results of comparative examples 1-6

[0064] index Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Sanding time, h 4.5 4.5 5 5 5 5.5 Particle size D90 at 0 days, μm 0.841 0.804 0.687 0.779 0.861 0.873 14-day thermal storage particle size D90, μm 1.832 1.707 0.815 1.021 2.597 3.169 14-day thermal storage particle size D90 growth rate, % 117.84 112.31 18.63 31.07 201.63 263.00 14-day heat storage water separation rate, % 30.00 23.68 4.76 13.33 32.56 64.10 7 days cold storage particle size D90, μm 1.534 1.295 0.772 0.997 2.333 2.865 7-day cold storage particle size D90 growth rate, % 82.40 61.07 12.37 27.98 170.96 228.18 7-day cold storage preparation water separation rate, % 13.89 19.05 4.44 14.63 20.00 30.77 Normal storage for 1 month Particle size D90, μm 1.685 1.328 0.776 1.106 2.007 2.216 Particle size D90 growth rate after 1 month storage, % 100.36 65.17 12.95 41.98 133.10 153.84 Water separation rate of the preparation after 1 month of storage, % 11.36 21.05 4.44 15.38 19.51 27.91 Heat storage to room temperature for 1 month Particle size D90, μm 2.109 1.908 0.932 1.153 8.733 22.119 Particle size D90 growth rate after heat storage to room temperature for 1 month, % 150.77 137.31 35.66 48.01 914.29 2433.68 Water separation rate of the preparation after heat storage and room temperature for 1 month, % 34.88 26.83 7.32 18.60 36.59 69.05

[0065] Conclusion: In comparative examples 1-6, the wetting dispersant can grind the sample particle size to D90 less than 1 μm, but the particle size increases to varying degrees after hot storage and hot storage to room temperature for one month. After hot storage to room temperature for one month, some samples have different degrees of increase in particle size, and most of the wetting dispersants take a long time to grind, the grinding particle size is large, and the water separation rate after hot storage to room temperature for one month is also relatively high. It can be seen that compared with other dispersant combinations, the dispersant combination used in Examples 1 to 3 is more conducive to improving the sand milling efficiency, and improves the particle size stability and appearance stability of the obtained nanomaterial-containing triacontanol benzylaminopurine suspension with a particle size of D90 <800nm. In comparative examples 7-8, the wetting dispersant can grind the sample particle size to D90 less than 1 μm, but the particle size increases greatly after hot storage and hot storage to room temperature for one month, D90 is close to or even exceeds 1 μm, and the water separation rate is also significantly increased. It can be seen that too little or too much of the wetting and dispersing agents 3275 and 3219 will destroy the balance of the system and cause the instability of the preparation. The mass ratio of the wetting and dispersing agents 3275 and 3219 can only achieve the effect of the present invention within the range of 1: (3.5-6), ensuring the particle size stability and appearance stability of the triacontanol benzylaminopurine suspension containing nanomaterials with a particle size D90 < 800nm. In Comparative Example 9, the nanomaterial Se-CDs is directly added to the ordinary triacontanol benzylaminopurine nanosuspension. Due to the significant particle size difference, the preparation has a significant particle size growth, and the water separation rate increases significantly, which is not conducive to the stability of the preparation.

[0066] Experiment 2: Verification of the efficacy of pesticide formulations containing Se-CDs, triacontanol and benzylaminopurine

[0067] Test method: Treat wheat with different pesticide formulations, and measure the wheat yield under different treatments. The treatment method is to spray wheat once in the early heading stage and flowering stage, and the concentration of the pesticide is 5ppm (dilution factor 8000) and 10ppm (dilution factor 4000), respectively, and clean water is used as a control.

[0068] The tested pesticide formulations are shown in Table 9 below, and the test results are shown in Table 10 below.

[0069] Table 9. Information of pesticide formulations tested

[0070] serial number Dosage form Remark A 4% benzylamine·triacontanol suspension containing nanomaterial Se-CDs Prepared according to the composition of comparative example 9 B 4% benzylamine·triacontanol nanosuspension without nanomaterial Se-CDs Prepared according to the composition of Example 1 C 4% benzylamine·triacontanol nanosuspension containing nanomaterial Se-CDs Prepared according to the composition of Example 1 CK Clean water treatment —

[0071] Table 10. Wheat yields treated with different pesticide formulations

[0072]

[0073]

[0074] Conclusion: Compared with the control, treatments A, B, and C can all increase wheat yields to varying degrees at 5ppm and 10ppm; treatment A has a lower yield-increasing effect at 10ppm than C, indicating that the benzylamino·triacontanol preparation is more conducive to the exertion of drug efficacy after nano-ization, and the amount of medicine used can be reduced; treatment B has a lower yield-increasing effect at 10ppm than treatment C, indicating that the nanomaterial Se-CDs can increase wheat yield to a certain extent, and the simultaneous application of nanomaterial Se-CDs and benzylamino·triacontanol preparations reduces the number of medications and increases wheat yield. Therefore, the benzylamino·triacontanol nanosuspension containing nanomaterial Se-CDs provided by the present invention can significantly improve drug efficacy, help reduce the amount of medicine used, and help reduce the number of times the medicine is applied, thereby reducing planting costs.

[0075] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A pesticide preparation containing Se-CDs, benzylaminopurine and triacontanol, characterized in that: The pesticide preparation is a nano suspension prepared from benzylaminopurine technical, triacontanol technical, Se-CDs nano material and auxiliary agents as raw materials, the particle size D90 of solid particles in the nano suspension is less than or equal to 800nm; the auxiliary agents include a wetting dispersant, a thickener, a rheological agent, an antifreeze agent, a preservative, a defoaming agent and deionized water, and the wetting dispersant is composed of an anionic-nonionic wetting dispersant SP-SC3219 and a weak cationic wetting dispersant SP-SC3275.

2. A pesticide preparation containing Se-CDs, benzylaminopurine and triacontanol according to claim 1, characterized in that: The percentage of the raw materials in the total weight of the nano suspension is: 2-8% of benzylaminopurine original drug, 0.2-0.4% of triacontanol original drug, 1-5% of Se-CDs nanomaterial, 5-15% of wetting dispersant, 0.2-0.5% of thickener, 0.1-0.5% of rheological agent, 3-5% of antifreeze agent, 0.1-0.5% of preservative, 0.1-0.5% of defoaming agent, and the balance is deionized water.

3. A pesticide preparation containing Se-CDs, benzylaminopurine and triacontanol according to claim 1, characterized in that: The mass ratio of SP-SC3219 to SP-SC3275 in the wetting and dispersing agent is 1:(3.5-6).

4. A pesticide preparation containing Se-CDs, benzylaminopurine and triacontanol according to claim 3, characterized in that: The mass ratio of SP-SC3219 to SP-SC3275 in the wetting and dispersing agent is 1:

4.

5. A pesticide preparation containing Se-CDs, benzylaminopurine and triacontanol according to claim 1, characterized in that: The thickener is selected from at least one of xanthan gum, gum arabic, methyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone and bentonite.

6. A pesticide preparation containing Se-CDs, benzylaminopurine and triacontanol according to claim 1, characterized in that: The rheological agent is selected from at least one of magnesium aluminum silicate, fumed titanium dioxide and white carbon black.

7. A pesticide preparation containing Se-CDs, benzylaminopurine and triacontanol according to claim 1, characterized in that: The antifreeze agent is selected from at least one of ethylene glycol, propylene glycol, glycerol, polyethylene glycol, sorbitol and urea.

8. The pesticide preparation containing Se-CDs, benzylaminopurine and triacontanol according to claim 1, characterized in that: The preservative is selected from at least one of KSG-401 and sodium benzoate.

9. The pesticide preparation containing Se-CDs, benzylaminopurine and triacontanol according to claim 1, characterized in that: The defoaming agent is selected from at least one of DF-66 and M9313.

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