Emulsifiable micro-particle agent for replacing granular pesticide droplets as well as preparation method and application of emulsifiable micro-particle agent

Abstract

The invention discloses an emulsifiable micro-particle agent for replacing granular pesticide droplets as well as a preparation method and application of the emulsifiable micro-particle agent. The emulsifiable micro-particle agent is prepared from 0.4 to 0.6 part of raw pesticide, 10 to 20 parts of dispersing agent, 2 to 10 parts of wetting agent, 0.1 part of defoaming agent, 70 to 90 parts of filler and 60 to 150 parts of deionized water. According to the invention, the emulsifiable micro-particle agent is prepared by replacing the granulation of the pesticide droplets, so that the evaporation drift loss of the pesticide droplets in the spraying process is reduced. The particle size of the emulsifiable micro-particle agent is 100-150 [mu] m, and the bulk density is 1.040 + / -0.005 g / cm < 3 >. After the emulsifiable micro-particle agent settles to wet the cotton leaf surfaces, no loss behaviors such as splashing and rebounding are generated, and the emulsifiable micro-particle agent can be well deposited on the cotton leaf surfaces with different inclination angles. Through observation of an ultra-depth-of-field microscope, the emulsifiable microparticle agent is rapidly disintegrated, emulsified and dispersed after contacting wet cotton leaves, and the wetting spreading area of the emulsifiable microparticle agent on the cotton leaves is relatively uniform.

Description

Technical Field

[0001] The invention relates to the technical field of new pesticide formulations, in particular to an emulsifiable microgranule for replacing pesticide droplet granulation, and a preparation method and application thereof. Background Art

[0002] The use of pesticides is generally divided into the following: ① The liquid is atomized through the nozzle; ② The droplets move and diffuse in the air, depositing on the target canopy or drifting outside the target; ③ The droplets collide and spread on the canopy surface; ④ The droplets are absorbed by the canopy surface and transmitted to the damaged parts to exert their efficacy. Droplet drift refers to the behavior of pesticide droplets being carried by airflow away from the target canopy, flowing to the ground or suspended in the atmosphere during the application process. This is considered to be the "culprit" of pesticide pollution, causing irreversible harm to aquatic plants and animals in surrounding rivers, the atmospheric environment, and human health.

[0003] Pesticide utilization rate refers to the ratio of the amount of pesticide deposited on the target per unit area to the total amount of pesticide used, that is, the deposition rate. During the distance from the pesticide box to the crop leaves, the droplets will evaporate and drift, resulting in a loss of dosage; at the same time, when the pesticide droplets collide with the crop leaves, the interface transfer such as bouncing, breaking, splashing, and loss will also cause a loss of dosage; finally, the remaining pesticide droplets on the leaves will enter the crops, weeds, and insects through a complex absorption and transportation process, resulting in a loss of dosage. Therefore, there is a huge gap between the actual amount of pesticide used and the actual amount of pesticide utilized.

[0004] Therefore, how to solve the evaporation drift problem of pesticide droplets during spatial operation, improve the pesticide deposition rate and actual utilization rate, and achieve pesticide reduction and efficiency improvement are still the main problems that need to be solved. Summary of the invention

[0005] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is how to reduce the evaporation drift loss of pesticide droplets during the spraying process, and to provide an emulsifiable microgranule as a granular alternative to pesticide droplets, and a preparation method and application thereof.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] The invention provides an emulsifiable microgranule for replacing the granularity of pesticide droplets. The emulsifiable microgranule comprises, by weight, 0.4-0.6 parts of pesticide original drug, 10-20 parts of dispersant, 2-10 parts of wetting agent, 0.1 parts of defoamer, 70-90 parts of filler and 60-150 parts of deionized water.

[0008] Preferably, the dispersant is a polycarboxylate dispersant; the wetting agent is Lakai powder BX; the defoaming agent is SAG 1572; and the filler is barium sulfate and / or kaolin.

[0009] Preferably, the pesticide technical is flonicamid technical; the dispersant is polycarboxylate dispersant GY-DF588; and the filler is barium sulfate.

[0010] Preferably, the emulsifiable microgranules include, by weight: 0.535 parts of pesticide technical, 20 parts of dispersant, 8 parts of wetting agent, 0.1 parts of defoaming agent, 71.365 parts of filler and 66 parts of deionized water.

[0011] The present invention provides a method for preparing the emulsifiable microgranules, comprising the following steps:

[0012] (1) Weigh each component according to the raw material ratio and set aside;

[0013] (2) mixing the raw material components and stirring them evenly to obtain a slurry;

[0014] (3) grinding the slurry to obtain a solid-liquid suspension system;

[0015] (4) The solid-liquid suspension system is subjected to spray granulation treatment to obtain the product.

[0016] Preferably, the total mass of the mixture is calculated as the total mass of the pesticide technical, dispersant, wetting agent, defoaming agent and filler; the total mass of the mixture in the raw material composition of the emulsifiable microgranules is 100 parts; the mass of the slurry is the sum of the total mass of the mixture and the mass of deionized water; the solid content is calculated as the percentage of the total mass of the mixture to the mass of the slurry; and the solid content of the slurry in step (2) is 40%-60%.

[0017] Preferably, in the step (3), the grinding speed is 2000 rpm, the grinding time is 60-120 min; the particle size of the particles in the solid-liquid suspension system after grinding is 140-330 nm;

[0018] In the step (4), during the spray granulation treatment, the hot air inlet temperature is 120-150° C., and the air outlet temperature is 60-70° C.; the frequency of rotation of the atomizer of the spray granulation dryer is 70-90 Hz.

[0019] Preferably, in step (2), the solid content of the slurry is 60%;

[0020] In the step (4), during the spray granulation treatment, the hot air inlet temperature is 150° C.; and the frequency of rotation of the atomizer of the spray granulation dryer is 90 Hz.

[0021] Preferably, in step (4), the particle size of the emulsifiable microgranules obtained is 100-150 μm, and the bulk density of the emulsifiable microgranules is 1.040±0.005 g / cm 3 .

[0022] The present invention provides an application of the emulsifiable microgranules in preparing pesticide preparations.

[0023] The technical solution of the present invention achieves the following beneficial technical effects:

[0024] The present invention proposes to prepare emulsifiable microgranules by replacing the granulation of pesticide droplets, in order to reduce the evaporation drift loss of pesticide droplets during the spraying process. A relatively stable solid-liquid suspension system is obtained by screening the types of dispersants and wetting agents and optimizing the dosage, and further adjusting and optimizing the parameters of spray granulation by orthogonal test method, and determining the optimal spraying conditions, which are: the frequency of atomizer rotation is 90Hz, the solid content is 60%, and the hot air inlet temperature is 150℃. At the same time, kaolin and precipitated barium sulfate are selected as carriers to prepare emulsifiable microgranules with different specific gravities in different proportions. Finally, emulsifiable microgranules are prepared by using 20% ​​GY-DF588, 8% pull-open powder BX and barium sulfate as carriers. The microgranules have a smooth surface morphology, a regular and uniform spherical shape, a nearly transparent color, a particle size range of about 100-150μm, and a bulk density of 1.040±0.005g / cm 3 . And further observed through high-speed photography that the emulsifiable microgranules did not splash, rebound or other loss behaviors after settling to the wet cotton leaf surface, and could be well deposited on the cotton leaf surface at different inclination angles. The ultra-depth-of-field microscope observed that the emulsifiable microgranules quickly disintegrated and emulsified after contacting the wet cotton leaves, and the wetted spreading area on the cotton leaf surface was relatively uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The morphology of the emulsifiable microgranules prepared in Example 1 of the present invention;

[0026] The left and right images are in different fields of view, and the scale is 100 μm;

[0027] Figure 2 The bouncing behavior of the emulsifiable microgranules prepared in Example 1 of the present invention on cotton leaves at different inclination angles (0°, 30°, 60°);

[0028] The left picture is during the bounce, and the right picture is after the bounce.

[0029] Figure 3 Emulsification deposition behavior of the emulsifiable microgranules prepared in Example 1 of the present invention on cotton leaves;

[0030] Among them, (a)(b)(c)(d) are under different fields of view, and the scale bar is 500μm. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and technical effect of the invention of this application clearer, the technical scheme in the embodiment of this application will be clearly and completely described below in conjunction with the drawings in the embodiment of this application. Obviously, the described embodiment is a part of the embodiment of this application, not all the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0032] In view of the technical problems existing in the prior art, the present invention provides an emulsifiable microgranule for replacing the granularity of pesticide droplets. The emulsifiable microgranule comprises, by weight: 0.4-0.6 parts (for example, 0.4 parts, 0.5 parts or 0.6 parts) of pesticide original drug, 10-20 parts (for example, 10 parts, 15 parts or 20 parts) of dispersant, 2-10 parts (for example, 2 parts, 4 parts, 6 parts, 8 parts or 10 parts) of wetting agent, 0.1 parts of defoaming agent, 70-90 parts (for example, 70 parts, 80 parts or 90 parts) of filler and 60-150 parts (for example, 60 parts, 66 parts, 80 parts, 100 parts, 120 parts or 150 parts) of deionized water;

[0033] In a preferred embodiment of the present invention, the emulsifiable microgranules include, by weight: 0.535 parts of pesticide technical, 20 parts of dispersant, 8 parts of wetting agent, 0.1 parts of defoamer, 71.365 parts of filler and 66 parts of deionized water;

[0034] The pesticide technical is flonicamid technical; the dispersant is a polycarboxylate dispersant; the wetting agent is Lakai powder BX; the defoamer is SAG 1572; the filler is barium sulfate and / or kaolin;

[0035] The fillers are barium sulfate and kaolin; the weight ratio of barium sulfate to kaolin is: (1-4):(4-1) (for example, 1:4, 2:3, 1:1, 3:2 or 4:1);

[0036] Among them, kaolin is a kind of clay and clay rock mainly composed of kaolinite clay minerals, with a theoretical density of 2.54-2.60 g / cm 3 Precipitated barium sulfate is an inorganic salt with a theoretical density of 4.50 g / cm 3 , both of which are cheap and readily available materials, and are often used as carriers or fillers in pesticide formulation processing.

[0037] In a preferred embodiment of the present invention, the dispersant is a polycarboxylate dispersant GY-DF588; the filler is barium sulfate;

[0038] Among them, GY-DF588 is a polycarboxylate dispersant, which will be adsorbed to the surface of the original drug and carrier material particles during the grinding process, providing dual protection through electrostatic repulsion and steric hindrance. When the amount of dispersant is too low, its adsorption on the surface of the original drug and carrier material is low, and the degree of particle wrapping is low, so the disintegration is poor. In addition, the degree of particle crushing also decreases with the amount of dispersant, mainly because the polycarboxylate dispersant GY-DF588 has a certain bonding effect, which can reduce the particle crushing ratio by improving the mechanical strength of the particles.

[0039] The present invention provides a method for preparing an emulsifiable microgranule for replacing the granularity of pesticide droplets, comprising the following steps:

[0040] (1) Weigh each component according to the raw material ratio and set aside;

[0041] (2) mixing the raw material components and stirring them evenly to obtain a slurry;

[0042] (3) grinding the slurry to obtain a solid-liquid suspension system;

[0043] (4) The solid-liquid suspension system is subjected to spray granulation treatment to obtain the product.

[0044] In the step (2), the solid content of the slurry is 40%-60% (for example, 40%, 50% or 60%);

[0045] The total mass of the mixture is calculated as the total mass of the pesticide technical, dispersant, wetting agent, defoamer and filler; the total mass of the mixture in the raw material composition of the emulsifiable microgranules is 100 parts; the mass of the slurry is the sum of the total mass of the mixture and the mass of deionized water;

[0046] The solid content is: the percentage of the total mass of the mixture to the mass of the slurry;

[0047] In a preferred embodiment of the present invention, in step (2), the solid content of the slurry is 60%;

[0048] In the step (3), the grinding speed is 2000 rpm, and the grinding time is 60-120 min (for example, 60 min, 80 min, 100 min or 120 min);

[0049] The diameter of the zirconium oxide beads used in grinding is 0.3 mm, and the filling amount of the slurry is 80% of the grinding chamber cavity; the particle size of the solid-liquid suspension system after grinding is 140-330 nm;

[0050] In the step (4), the solid-liquid suspension system is transferred to the atomizer at the top of the spray granulation dryer by a rotary pump at a rotation speed of 12.0 rpm; the material is atomized into fine droplets by a high-speed rotating centrifugal disk in the atomizer, and then fully mixed with hot air heated by an electric heater to achieve the purpose of instant drying;

[0051] In the step (4), during the spray granulation treatment, the hot air inlet temperature is 120-150° C. (for example, 120° C., 135° C., 140° C. or 150° C.), and the air outlet temperature is 60-70° C. (for example, 60° C., 65° C. or 70° C.); the frequency of rotation of the atomizer of the spray granulation dryer is 70-90 Hz (for example, 70 Hz, 80 Hz or 90 Hz);

[0052] In a preferred embodiment of the present invention, in step (4), during the spray granulation treatment, the hot air inlet temperature is 150° C.; the frequency of rotation of the atomizer of the spray granulation dryer is 90 Hz;

[0053] In step (4), the particle size of the emulsifiable microgranules obtained is 100-150 μm, and the bulk density of the emulsifiable microgranules is 1.040±0.005 g / cm 3 .

[0054] The invention provides an application of an emulsifiable microgranule as a substitute for the granularity of pesticide droplets in the preparation of pesticide preparations.

[0055] The following is a detailed description of an emulsifiable microgranule for replacing the pesticide droplet granulation, and a preparation method and application thereof of the present invention through specific embodiments.

[0056] Materials and instruments used in the embodiments of the present invention:

[0057] Table 1 Experimental materials

[0058] Experimental Materials Manufacturer 96% Fluphenacamide technical Shandong Jingbo Biotechnology Co., Ltd. Polycarboxylate dispersant GY-DF588 Beijing Guangyuan Yino Chemical Co., Ltd. Polycarboxylate dispersant GY-DF598 Beijing Guangyuan Yino Chemical Co., Ltd. Polycarboxylate dispersant GY-DF619 Beijing Guangyuan Yino Chemical Co., Ltd. Polycarboxylate dispersant GY-DF629 Beijing Guangyuan Yino Chemical Co., Ltd. Polycarboxylate dispersant GY-DF639 Beijing Guangyuan Yinong Chemical Co., Ltd. Wetting agent (pulling powder BX) Shanghai Tiantan Additives Co., Ltd. Defoaming agent (SAG1572) Nanjing Jierun Technology Co., Ltd. Kaolin Shanghai MacLean Biochemical Technology Co., Ltd. Precipitated barium sulfate Lingshou County Zhanteng Mineral Products Processing Factory

[0059] Table 2 Experimental instruments

[0060] Experimental instruments model factory Electronic balance ME204T MettlerToledo Nano sand mill VB0.3Q Suzhou Micro Nano Technology Co., Ltd. Spray granulation dryer PL-1000 Jiangyin Zhuoying Drying Engineering Technology Co., Ltd. Laser Particle Size Analyzer BT-9300H Dandong Better Instrument Co., Ltd. Nano laser particle size analyzer BeNano180Zeta Dandong Better Instrument Co., Ltd. High-speed centrifuge TG16G Jintan Technology Analysis Instrument Company Ultra-deep-field 3D microscope system VHX-2000 KEYENCE Ultra-high-speed photography Photron,FastcamApx-Rs Japan Photron

[0061] Example 1 Preparation method of emulsifiable microgranules for replacing pesticide droplet granulation

[0062] This embodiment provides an emulsifiable microgranule for replacing the granularity of pesticide droplets. The emulsifiable microgranule comprises, by weight, 0.535 parts of the pesticide technical (96% flonicamid technical), a dispersant

[0063] (polycarboxylate dispersant GY-DF588) 20 parts, wetting agent (pulling powder BX) 8 parts, defoamer (SAG 1572) 0.1 parts, filler (barium sulfate) 71.365 parts and deionized water 66 parts;

[0064] The preparation method of the pesticide droplet granulation alternative emulsifiable microgranules comprises the following steps:

[0065] (1) Weigh each component according to the raw material ratio and set aside;

[0066] (2) mixing the raw material components and stirring them evenly to obtain a slurry;

[0067] The total mass of the mixture is calculated as the total mass of the pesticide technical, dispersant, wetting agent, defoamer and filler; the solid content of the slurry is 60%; the solid content is: the percentage of the total mass of the mixture to the mass of the slurry;

[0068] (3) grinding the slurry, wherein the diameter of the zirconium oxide beads used in the grinding is 0.3 mm, and the filling amount of the slurry is 80% of the grinding chamber cavity; the grinding speed is 2000 rpm, and the grinding time is 120 min; and a solid-liquid suspension system is obtained;

[0069] (4) The solid-liquid suspension system is transferred to the atomizer at the top of the spray granulation dryer by a rotary pump at a rotation speed of 12.0 rpm; during the spray granulation treatment, the hot air inlet temperature is 150° C. and the air outlet temperature is 60° C.; the frequency of the atomizer rotation of the spray granulation dryer is 90 Hz; after the spray granulation treatment, the product is obtained.

[0070] Characterization of emulsifiable microgranules:

[0071] ① Morphology observation: Weigh 0.1 g of emulsifiable microparticles and add them to a culture dish with a diameter of 90 mm. Gently shake the culture dish to evenly disperse the microparticles. Use an ultra-depth of field microscope to observe the sample morphology.

[0072] ② Particle size test: dilute the solid-liquid suspension system or emulsifiable microgranules 200 times with deionized water, and use a laser particle size analyzer to measure the Z-average particle size (Z-average particle size) and polydispersity index (PDI) of the suspension system or emulsifiable microgranules after disintegration at room temperature.

[0073] Example 2 Screening and Dosage Optimization of Dispersants

[0074] (1) This embodiment provides an emulsifiable microgranule that replaces the granularity of pesticide droplets. The difference from Example 1 is that the type of dispersant is different. In this embodiment, the polycarboxylate dispersant GY-DF588 in Example 1 is replaced by: GY-DF598, GY-DF619, GY-DF629, GY-DF639 respectively; the selection and dosage of other raw material components are the same as in Example 1.

[0075] The preparation method of the pesticide droplet granulation alternative emulsifiable microgranules is the same as that of Example 1 (only the grinding time of step (3) is adjusted to 60-120 minutes). At the same time, the grinding efficiency (i.e., the grinding time of the slurry when preparing the solid-liquid suspension system in step (3)) and the appearance of the microgranules after spray granulation are used as evaluation indicators to determine the best dispersant type.

[0076] The experimental results show that ① the particle size of the suspension system prepared by GY-DF588, GY-DF619 and GY-DF629 as dispersants decreases with the increase of grinding time, while the particle size of the suspension system prepared by GY-DF598 and GY-DF639 as dispersants shows a trend of first decreasing and then increasing with the increase of grinding time. ② The particle size of the suspension system prepared by the five dispersants after grinding for the same time (grinding time is 120min) is all at the nanometer level, and the polydispersity index is less than 0.3, and the particle size distribution is uniform; the particle size and polydispersity index of the suspension system prepared by dispersant GY-DF639 are the largest; the particle size of the suspension system prepared by dispersant GY-DF619 is the smallest, and the polydispersity index of the suspension system prepared by dispersant GY-DF588 is the lowest. ③ The morphology of microparticles prepared with five dispersants before and after disintegration was observed using an ultra-depth-of-field microscope (grinding time was 120 min). The microparticles prepared with dispersants GY-DF588 and GY-DF598 were not broken and disintegrated completely; while the microparticles prepared with dispersants GY-DF619, GY-DF629, and GY-DF639 were easily broken and had poor disintegration.

[0077] Therefore, the suspension system prepared with the dispersant GY-DF588 has a smaller particle size and a smaller polydispersity index, that is, the particle size distribution is more uniform. The present invention selects GY-DF588 as the best dispersant.

[0078] (2) This embodiment provides an emulsifiable microgranule as an alternative to pesticide droplet granulation. The difference from Embodiment 1 is that the amount of dispersant used is different; wherein, when the amount of dispersant is adjusted, the amount of filler (barium sulfate) is increased or decreased accordingly to ensure that the total mass of the pesticide original drug, dispersant, wetting agent, defoaming agent, and filler is 100 parts (wherein, the total mass of the mixture is calculated as the total mass of the pesticide original drug, dispersant, wetting agent, defoaming agent, and filler; the total mass of the mixture in the raw material composition of the emulsifiable microgranule is 100 parts).

[0079] In this embodiment, 20 parts by mass of the polycarboxylate dispersant GY-DF588 in Example 1 are replaced by 10 parts by mass and 15 parts by mass, respectively, and the amount of filler is increased accordingly (i.e., the amount of the dispersant is 10%, 15% and 20% of the total mass of the mixture, respectively). The selection and amount of other raw material components are the same as in Example 1.

[0080] The preparation method of the pesticide droplet granulation alternative emulsifiable microgranules is the same as that of Example 1. The bisection method is adopted, and the appearance and disintegration of the microgranules after spray granulation are used as evaluation indicators to optimize the amount of the dispersant.

[0081] The experimental results show that when the dosage of dispersant GY-DF588 is 10%, the particles cannot be completely disintegrated, and most of the particles are broken; when the dosage of dispersant is increased to 15%, the disintegration of the particles is improved, but there are still many broken particles; and when the dosage of dispersant is 20%, the particle size distribution of nanoparticles produced after the particle disintegration is almost consistent with the original particle size distribution in the suspension system, indicating that the particles are completely disintegrated. Observing their morphology under an ultra-depth of field microscope also shows that the degree of particle breakage is low.

[0082] Example 3 Optimization of wetting agent dosage

[0083] This embodiment provides an emulsifiable microgranule as an alternative to pesticide droplet granulation. The difference from Embodiment 1 is that the amount of the wetting agent is different; wherein, while adjusting the amount of the wetting agent, the amount of the filler (barium sulfate) is increased or decreased accordingly to ensure that the total mass of the pesticide original drug, dispersant, wetting agent, defoaming agent, and filler is 100 parts (wherein, the total mass of the mixture is calculated as the total mass of the pesticide original drug, dispersant, wetting agent, defoaming agent, and filler; the total mass of the mixture in the raw material composition of the emulsifiable microgranule is 100 parts).

[0084] In this embodiment, 8 parts by mass of the wetting agent BX in embodiment 1 are replaced by 2 parts by mass, 4 parts by mass, 6 parts by mass, and 10 parts by mass, respectively, and the amount of filler is increased accordingly (i.e., the amount of the wetting agent is 2%, 4%, 6%, 8% and 10% of the total mass of the mixture, respectively). The selection and amount of other raw material components are the same as those in embodiment 1.

[0085] The preparation method of the emulsifiable microgranules that replace the pesticide droplet granulation is the same as that of Example 1. Referring to GB / T5451-2001 "Method for Determining the Wettability of Pesticide Wettable Powders", the wetting time is used as an evaluation index to investigate the effect of the amount of wetting agent BX on the wetting time of the emulsifiable microgranules, and optimize the amount of wetting agent. Take 100mL±1mL of standard hard water, inject it into a 250mL beaker, use weighing paper to weigh 0.1g of sample, and pour it evenly on the liquid surface of the beaker at one time, but do not disturb the liquid surface excessively. While adding the sample, immediately start the stopwatch until the sample is completely wetted, and record the wetting time, accurate to seconds. Repeat the test 5 times, and then take the average value as the wetting time of the sample.

[0086] The experimental results show that when the wetting agent dosage is 8%, the wetting time of the emulsifiable microgranules is only 8.82s. After further increasing the wetting agent dosage to 10%, the wetting time is shortened to 7.88s, but the difference is not significant. Therefore, the optimal dosage of the wetting agent is determined to be 8%.

[0087] Example 4 Optimization of spray granulation conditions

[0088] This embodiment provides an emulsifiable microgranule as an alternative to pesticide droplet granulation. The raw material composition of the emulsifiable microgranule is different from that of Example 1 in that the content of deionized water (i.e., solid content) is different; the preparation method thereof is different from that of Example 1 in that the hot air inlet temperature and the frequency of rotation of the atomizer during the spray granulation treatment in step (4) are different;

[0089] The preparation process of emulsifiable microgranules was optimized by orthogonal experimental design. 4 ) The orthogonal experiment investigated the effects of three factors, namely the frequency of atomizer rotation (70Hz, 80Hz, 90Hz), the hot air inlet temperature (120℃, 135℃, 150℃) and the solid content (40%, 50%, 60%), on the yield and particle size distribution. A total of 9 experiments were conducted.

[0090] From the experimental results, it can be seen that ① the influence of the three factors on the yield is in the order of solid content > hot air inlet temperature > atomizer rotation frequency. When the yield is used as the evaluation index (yield = total mass of microgranules obtained after spray granulation / total mass of raw materials × 100%), the highest yield levels corresponding to the three factors are atomizer rotation frequency of 80Hz, hot air inlet temperature of 150°C, and solid content of 60%.

[0091] ② Since particles with a size of less than 50 μm have a higher risk of drifting, and particles with a size of more than 200 μm are difficult to disintegrate and disperse, particles with a size range of 50 to 200 μm are more suitable for spraying. Therefore, further analysis of the influence of the three factors on particle size distribution shows that the order is solid content > frequency of atomizer rotation > hot air inlet temperature. When the proportion of particles with a size of 50 to 200 μm is used as an evaluation index, the highest yield levels corresponding to the three factors are when the frequency of atomizer rotation is 70 Hz, the solid content is 40%, and the hot air inlet temperature is 120°C.

[0092] ③ Since the optimal combination obtained when the highest yield and the highest proportion of particle size 50-200μm are used as evaluation indicators are different, it is necessary to consider the optimal level when the target yield is used as the evaluation indicator under the condition of the superposition of the two factors. Target yield = yield × proportion of 50-200μm.

[0093] The results show that the influence of the three factors on the target yield is in the order of atomizer rotation frequency > solid content > hot air inlet temperature. When the target yield is used as the evaluation index, the highest yield levels corresponding to the three factors are 90 Hz atomizer rotation frequency, 60% solid content, and 150°C hot air inlet temperature.

[0094] Example 5: Screening and Dosage Optimization of Fillers

[0095] This embodiment provides an emulsifiable microgranule for replacing the granularization of pesticide droplets. The difference from Embodiment 1 is that the type of filler is different. In this embodiment, the filler barium sulfate in Embodiment 1 is replaced by a composite carrier filler of barium sulfate and kaolin. Emulsifiable microgranules with different specific gravities are prepared by adjusting the filler ratio.

[0096] The weight ratios of barium sulfate and kaolin in the composite carrier filler used in this example are 1:4, 2:3, 1:1, 3:2, and 4:1, respectively. The selection and dosage of other raw material components are the same as those in Example 1. The preparation method of the pesticide droplet granular substitute emulsifiable microgranules is the same as that in Example 1.

[0097] The experimental results show that ① the emulsifiable microgranules prepared with different carriers are all spherical, with a particle size range of 50-150μm. When the ratio of kaolin and precipitated barium sulfate is different, the degree of breakage of the prepared emulsifiable microgranules is low, indicating that they all have strong mechanical strength. ② The particle size distribution of microgranules prepared with different carriers before and after disintegration is almost the same, indicating that the formula is universal and can be used to prepare microgranules with different specific gravities.

[0098] like Figure 1As shown in the figure, the final screening formula of the present invention is 20% GY-DF588, 8% pull open powder BX, and barium sulfate as a carrier to prepare an emulsifiable microgranule (i.e., Example 1). Most of the morphology is spherical particles with smooth surface, regular and uniform shape, nearly transparent color, and a particle size range of about 100-150 μm. The bulk density of the emulsifiable microgranule is 1.040±0.005 g / cm 3 .

[0099] Example 6 Spatial Movement Behavior of Emulsifiable Microgranules

[0100] The falling process of the emulsifiable microgranules (obtained in Example 1) and the dynamic impact process after reaching the cotton leaf surface at different inclination angles were recorded by high-speed photography at a speed of 10,000 frames per second, with a resolution of 1024×1024. The height of the outlet of the emulsifiable microgranules from the leaf surface was set to 20 cm. The shadow image was analyzed by using Image-Pro Plus software to capture the spatial behavior process of the emulsifiable microgranules.

[0101] The motion of the axial particles in the granular flow is in a state of free fall, such as Figure 2 As shown, after reaching the wetted leaf surface, there is no splashing, rebounding or other loss behaviors, and finally the liquid can be well deposited on the cotton leaf surface at different inclination angles.

[0102] Example 7 Interfacial Deposition Behavior of Emulsifiable Microgranules

[0103] The ultra-depth three-dimensional microscope VHX-2000 was used to observe and record the emulsification and dispersion process (wetting behavior after effective deposition on the leaves) of the microparticles (obtained in Example 1) on the cotton leaf surface and the morphology after deposition at a magnification of 0.1-5000 times in depth and super-resolution imaging mode.

[0104] like Figure 3 As shown, the emulsifiable microgranules quickly disintegrate and emulsify and disperse after contacting the wet cotton leaves, and the wetted and spread area on the cotton leaf surface is relatively uniform.

[0105] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. An emulsifiable microgranule for replacing pesticide droplets, characterized in that: Calculated by weight, the emulsifiable microgranules include: 0.4-0.6 parts of pesticide original drug, 10-20 parts of dispersant, 2-10 parts of wetting agent, 0.1 parts of defoaming agent, 70-90 parts of filler and 60-150 parts of deionized water.

2. The emulsifiable microgranules according to claim 1, characterized in that The dispersant is a polycarboxylate dispersant; the wetting agent is Lakai powder BX; the defoaming agent is SAG 1572; and the filler is barium sulfate and / or kaolin.

3. The emulsifiable microgranules according to claim 2, characterized in that The pesticide technical is flonicamid technical; the dispersant is polycarboxylate dispersant GY-DF588; and the filler is barium sulfate.

4. The emulsifiable microgranules according to claim 3, characterized in that Calculated by weight, the emulsifiable microgranules include: 0.535 parts of pesticide original material, 20 parts of dispersant, 8 parts of wetting agent, 0.1 parts of defoaming agent, 71.365 parts of filler and 66 parts of deionized water.

5. The method for preparing the emulsifiable microgranules according to any one of claims 1 to 4, characterized in that: The following steps are involved: (1) Weigh each component according to the raw material ratio and set aside; (2) mixing the raw material components and stirring them evenly to obtain a slurry; (3) grinding the slurry to obtain a solid-liquid suspension system; (4) The solid-liquid suspension system is subjected to spray granulation treatment to obtain the product.

6. The preparation method according to claim 5, characterized in that: The total mass of the mixture is calculated as the total mass of the pesticide technical, dispersant, wetting agent, defoamer and filler; the total mass of the mixture in the raw material composition of the emulsifiable microgranule is 100 parts; the mass of the slurry is the sum of the total mass of the mixture and the mass of deionized water; the solid content is calculated as the percentage of the total mass of the mixture to the mass of the slurry; the solid content of the slurry in step (2) is 40%-60%.

7. The preparation method according to claim 5, characterized in that: In the step (3), the grinding speed is 2000 rpm, and the grinding time is 60-120 min; the particle size of the particles in the solid-liquid suspension system after grinding is 140-330 nm; In the step (4), during the spray granulation treatment, the hot air inlet temperature is 120-150° C., and the air outlet temperature is 60-70° C.; the frequency of rotation of the atomizer of the spray granulation dryer is 70-90 Hz.

8. The preparation method according to claim 6 or 7, characterized in that: In the step (2), the solid content of the slurry is 60%; In the step (4), during the spray granulation treatment, the hot air inlet temperature is 150° C.; and the frequency of rotation of the atomizer of the spray granulation dryer is 90 Hz.

9. The preparation method according to claim 5, characterized in that: In step (4), the particle size of the emulsifiable microgranules obtained is 100-150 μm, and the bulk density of the emulsifiable microgranules is 1.040±0.005 g / cm 3 .

10. Use of the emulsifiable microgranules according to any one of claims 1 to 4 in the preparation of pesticide formulations.

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