AU2019425012A1

AU2019425012A1 - Preparation method for pesticide dry flowable

Info

Publication number: AU2019425012A1
Application number: AU2019425012A
Authority: AU
Inventors: Kecheng Huang; Pengfei Li; Puchao LI; Kechao LIAO; Fenghua LUO
Original assignee: Shenzhen Noposion Agrochemicals Co Ltd
Current assignee: Shenzhen Noposion Agrochemicals Co Ltd
Priority date: 2019-01-21
Filing date: 2019-12-05
Publication date: 2021-01-14
Also published as: CN109730060A; WO2020151377A1

Abstract

A preparation method for a pesticide dry flowable, comprising: first selecting a high-performance dispersant to prepare a medium- or high-content pesticide suspension; then adding a water-soluble high temperature-resistant dispersant and a water-soluble disintegrant to the suspension system for shear mixing; and then performing spray drying to obtain a dry flowable product. The method is mainly suitable for original pesticide systems which are difficult to prepare high-content suspensions, such as low-melting point original pesticides having a melting point less than 80°C, highly water-soluble original pesticides having water solubility greater than 0.5g/L, and original pesticides easy to form hydrogen bonds and water clusters with water. The method can improve the ratio of solid content in a prepared suspended slurry during dry flowable preparation, reduce energy consumption for spray drying, and increase the granulation rate and particle size of the dry flowable.

Description

PREPARATION METHOD OF PESTICIDE DRY SUSPENSION TECHNICAL FIELD

The present application relates to the field of pesticide agent, and particularly relates to a preparation method of a pesticide dry suspension.

BACKGROUND Pesticide dry suspension agent needs to be prepared by wet grinding to prepare suspension slurry, and then spray-drying prepare the product. Pesticides are heat sensitive products. In order to prevent the active ingredients from agglomerating after high-temperature granulation, a dispersant with excellent heat resistance should be selected to wrap the original pesticide particles before spray drying to ensure that the product can be dispersed normally after being heated. Lignin-based dispersants have excellent heat resistance and have a large amount of negative charge. Lignin-based dispersants surround the surface of the original pesticide particles, which can ensure that the active ingredients do not agglomerate during the drying process and ensure product quality. Therefore, the high temperature resistant dispersant is the first choice of sodium lignosulfonate dispersant. At current stage, the wet pulverization process of pesticide dry suspension mostly involves mixing all required materials together, and then grinding them into a sand mill. In the wet pulverization process, in addition to requiring particles to achieve the required granularity, the suspension slurry needs to be prepared to have a higher solid content. High solid content has a positive effect on pulverization efficiency, energy saving during drying, and product granulation rate improvement. However, the increase in solid content will also increase the viscosity of the suspension slurry, which will cause problems for the crushing and transportation of materials. It is ideal to obtain a suspension slurry with high solid content and lower viscosity. However, some low melting, high-water-solubility original pesticide themselves are more difficult to prepare suspension with high solid content, and sometimes the solid content of the suspension slurry has to be reduced to ensure fluidity. In addition, some pesticide original pesticide have no compatibility with lignin dispersant. Adding lignin dispersant can not solve the dispersion problem, and it is impossible to obtain suspension slurry with high solid content. Only expensive high-temperature resistant polymers dispersant can be used, increasing the difficulty of preparation and processing cost. However, in wet grinding, a high-performance dispersant is used for high-speed grinding, and after grinding, sodium lignosulfonate with good heat resistance is added for shear mixing. Not only can it improve the grinding efficiency and the solid content of the suspended slurry, but it can also ensure that the original pesticide does not agglomerate due to high-temperature spray drying. TECHNICAL PROBLEM The embodiment of the present application provides a preparation method for a pesticide dry suspension to help increase the solid content of the existing suspension slurry, reduce energy consumption in the spray drying process, and improve product granularity.

BRIEF SUMMARY The embodiments of the present application are implemented in this way. In the first aspect, a preparation method for a pesticide dry suspension is provided. The specific steps are: a. Add original pesticide, high-performance dispersant, wetting agent, defoamer, filler and water in sequence pro rata, and stir evenly to form a mixture; b. The mixture obtained in step a is coarsely pulverized in a shearing kettle with a high-speed shearing machine, and then finely pulverized by a sand mill, and pulverized to a particle size of 1 m- 5 m; c. Add the high temperature resistant dispersant and the water-soluble dis-integrant to the suspension obtained in step b pro rata. After mixing, use the high-speed shearing machine to fully stir in the shearing kettle, and then enter the pressure spray dryer to spray, granulate to obtain finished pesticide dry suspension.

BENEFICIAL EFFECT In the embodiment of the present application, the preparation method can save energy to the utmost extent, and no high temperature resistant dispersant is added during the grinding process, which can ensure the fluidity of the suspension and improve the grinding efficiency; and compared with mixed sand grinding, it can significantly improve the solid content of the suspended slurry and reduce energy consumption during the spraying and granulation process.

DETAILED OF DESCRIPTION In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In order to help increase the solid content of the existing suspended slurry, reduce energy consumption in the spray drying process and improve product granularity. The purpose of the present application is to provide a pesticide dry suspension, the formula composition is: Original pesticide 50%~80%, high performance dispersant 2%~5%, wetting agent 1%~3%, high temperature resistant dispersant 10%~30%, water-soluble dis-integrant %~15%, defoamer 0.5%~1% and the rest is the filler. In order to achieve the above purpose of the present application, the present application adopts the following technical solutions: The present application provides a preparation method for a pesticide dry suspension, and the specific steps are: a. adding original pesticide , high-performance dispersant, wetting agent, defoamer, filler and water in sequence pro rata, and stirring evenly to form a mixture; b. The mixture obtained in step a is coarsely pulverized in a shearing kettle with a high-speed shearing machine, and then finely pulverized by a sand mill, and pulverized to a particle size of 1 m- 5 m; c. adding the high temperature resistant dispersant and the water-soluble dis integrant to the suspension obtained in step b pro rata. After mixing, using the high speed shearing machine to fully stir in the shearing kettle, and then entering into the pressure spray dryer to spray, granulating to obtain finished pesticide dry suspension. The preparation method of the present application is suitable for original pesticide system which is difficult to prepare high solid content suspension slurry. The original pesticide system is any one of a low-melting original pesticide with a melting point lower than 80°C, a high-water soluble original pesticide with a water solubility greater than 0.5g/L, an original pesticide which are easy to form hydrogen bonds and water clusters with water. Optionally, the low-melting-point original pesticide is pyraclostrobin original pesticide or difenoconazole original pesticide. Optionally, the high water-soluble original pesticide is imidacloprid original pesticide, thiamethoxam original pesticide or flonicamid original pesticide. Optionally, the original pesticide that easily forms hydrogen bonds and water clusters with water is the pymetrozine original pesticide. In an embodiment, the original pesticide the original pesticide is any one selected from the group consisting of the pymetrozine original pesticide, pyraclostrobin original pesticide, difenoconazole original pesticide, imidacloprid original pesticide, thiamethoxam original pesticide, and flonicamid original pesticide and a combination of any one of the pymetrozine original pesticide, pyraclostrobin original pesticide, difenoconazole original pesticide, imidacloprid original pesticide, thiamethoxam original pesticide, and flonicamid original pesticide with any one of the propineb original pesticide, zineb original pesticide, metiram original pesticide, Kresoxim methyl original pesticide, trifloxystrobin original pesticide, thiophanate methyl original pesticide, tebuconazole original pesticide, hexaconazole original pesticide, and the spirotetramat original pesticide. The wetting agent is at least one selected from the group consisting of sodium lauryl sulfate, sodium dodecyl benzene sulfonate, sodium alkenyl sulfonate, sodium naphthalene sulfonate, sulfosuccinate sodium salt, alkyl succinic sulfonate. The high-performance dispersant is at least one selected from the group consisting of polycarboxylate sodium salt, naphthalene sulfonate, alkyl naphthalene sulfonic acid formaldehyde condensate, di-alkyl succinic acid sulfonate, alkyl benzene sulfonate, fatty alcohol phosphate salts and lignosulfonates. Through the selection of high performance dispersants, the prepared suspension has good fluidity and low viscosity. The high-temperature resistant dispersant is lignosulfonate of different specifications. In specific embodiments, the lignosulfonate is at least one selected from the group consisting of Borresperse NA, Ufoxane 3A, Ultraazine NA in Borresperse series, and Westvaou's Polyton H, polyton 0, Reax 81A, Reax 82, Reax 83A, Reax 85A, Reax 88B, NSX-105, NSX-125, NSX-120, NSX-135, D-30 in the Lignosol series. The dis-integrant is at least one selected from the group consisting of potassium sulfate, sodium sulfate, ammonium sulfate, and urea.

The filler is kaolin. The preparation method of the present application can save energy to the utmost extent, does not add a high temperature resistant dispersant during the grinding process, can ensure the fluidity of the suspension and improve the grinding efficiency; and compared with the mixed sand mill, it can significantly increase the solid content of the suspension slurry and reduce energy consumption in the process of spraying and granulating. In order to illustrate the technical solution of the present application, specific embodiments are used for description below. Unless otherwise specified, all percentages in this specification refer to mass percentages.

Embodiment 1: Preparation of 50% pymetrozine dry suspension Formula composition: pymetrozine original pesticide 50%; wetting agent (sodium lauryl sulfate) 2%; high-performance dispersant (Alkyl naphthalene sulfonate formaldehyde condensate sodium salt) 3%; high temperature resistant dispersant (Ultrazine NA model sodium lignosulfonate) 25%; defoamer (20% polydimethylsiloxane emulsion) 0.5%; dis-integrant (potassium sulfate) 10%; the rest is the filler (kaolin). The preparation method is as follows: weighing 2 kg of wetting agent, 3 kg of high-performance dispersant, and 0.5 kg of defoamer into a mixing vessel filled with 150 kg of water, stirring to dissolve; then adding 50 kg of pymetrozine original pesticide, 9.5 kg of filler (kaolin) into the mixing vessel batch by batch, and stirring the mixture into a uniform slurry. The slurry was passed into three sand mills in series and sanded to obtain a suspension. Taking the pymetrozine suspension prepared above, adding 25 kg of high temperature resistant dispersant and 10 kg of water-soluble dis-integrant into the pymetrozine suspension, shear stirring for 20 min to make the dispersant completely mix uniformly to obtain a water suspension slurry sample with a solid content of 40%. The water suspension slurry was spray-dried into granules to obtain a 50% pymetrozine dry suspension.

Embodiment 2: Preparation of 70% pymetrozine dry suspension Formula composition: pymetrozine original pesticide 70%; wetting agent (sodium lauryl sulfate) 2%; high-performance dispersant (Alkyl naphthalene sulfonate formaldehyde condensate sodium salt) 5%; high temperature resistant dispersant (Ultrazine NA model sodium lignosulfonate) 20%; defoamer (20% polydimethylsiloxane emulsion) 0.5%; dis-integrant (potassium sulfate) 2.5%. The preparation method is as follows: weighing 2 kg of wetting agent, 5 kg of high-performance dispersant, and 0.5 kg of defoamer into a mixing vessel filled with 150 kg of water and stirring to dissolve; then adding 70 kg of pymetrozine original pesticide into the mixing vessel batch by batch , stirring the mixture into a uniform slurry, which is passed into three sand mills in series, and sanded to obtain a suspension.

Taking the pymetrozine suspension prepared above, adding 20kg of high-temperature resistant dispersant and 2.5kg of water-soluble dis-integrant into the pymetrozine suspension, shear stirring for 20 min to make the dispersant completely mix uniformly to obtain a water suspension slurry sample with a solid content of 40%. The water suspension slurry was spray-dried into granules to obtain 70% pymetrozine dry suspension.

Embodiment 3: Preparation of 55% pymetrozine-spirotetramat dry suspension Formula composition: pymetrozine original pesticide 40%; spirotetramat original pesticide 15%; wetting agent (sulfosuccinate octyl sodium salt) 2%; high-performance dispersant (dialkyl succinate sulfonate) 3%; high temperature resistant dispersant (Ultrazine NA model sodium lignosulfonate) 25%; defoamer (20% polydimethylsiloxane emulsion) 0.5%; dis-integrant (potassium sulfate) 10%; the rest is filler ( kaolin) .

The preparation method is as follows: weighing 2 kg of wetting agent, 3 kg of high-performance dispersant, and 0.5 kg of defoamer into a mixing vessel filled with 150 kg of water, stirring to dissolve; then adding 40 kg of pymetrozine original pesticide, kg of spirotetramat, 4.5 kg of filler (kaolin) into the mixing vessel batch by batch, and stirring the mixture into a uniform slurry, which was passed into three sand mills in series, and sanded to obtain a suspension. Taking the suspension prepared above, adding 25 kg of high temperature resistant dispersant and 10 kg of water-soluble dis integrant into the suspension, shear stirring for 20 min to make the dispersant completely mix uniformly to obtain a water suspension slurry sample with solid content of 40%. The water suspension slurry was spray-dried into granules to obtain 55% pymetrozine-spirobethin dry suspension.

Embodiment 4: Preparation of 70% imidacloprid dry suspension Formula composition: imidacloprid original pesticide70%; wetting agent (sodium naphthalene sulfonate) 2%; high-performance dispersant (polycarboxylate sodium salt dispersant) 3%; high temperature resistant dispersant (Reax 81A sodium lignosulfonate) %; defoamer (20% polydimethylsiloxane emulsion) 0.5%; dis-integrant (potassium sulfate) 4 .5%. Preparation method is as follows: weighing 2 kg of wetting agent, 3 kg of high performance dispersant, and 0.5 kg of defoamer into a mixing vessel filled with 82kg of water, stirring to dissolve; then adding 70 kg of imidacloprid original pesticide into the mixing vessel batch by batch, stirring the mixture into a uniform slurry, passing the slurry into three sand mills in series, and sanding to obtain a suspension. Taking the imidacloprid suspension prepared above, adding 20 kg of high-temperature resistant dispersant and 4.5 kg of water-soluble dis-integrant into the imidacloprid suspension, shear stirring for 20 minutes to make the dispersant completely mixed uniformly to obtain a water suspension slurry sample with solid content of 55%. The water suspension slurry was spray-dried into granules to obtain 70% imidacloprid dry suspension.

Embodiment 5: Preparation of 50% pyraclostrobin dry suspension Formula composition: pyraclostrobin original pesticide 50%; wetting agent (naphthalene sulfonate sodium salt) 3%; high-performance dispersant (alkyl naphthalene sulfonate formaldehyde condensate) 5%; high temperature resistant dispersant (polyton H Model sodium lignosulfonate) 25%; defoamer (20% polydimethylsiloxane emulsion) 0.5%; dis-integrant (urea) 10%; the rest is filler (kaolin) .

Preparation method is as follows: weighing 3 Kg of wetting agent, 5 kg of high performance dispersant, and 0.5 kg of defoamer into a mixing vessel filled with 150kg of water, stirring to dissolve; then adding 50 kg of pyraclostrobin original pesticide and 6.5 kg of filler (kaolin) into the mixing vessel batch by batch, and stirring the mixture into a uniform slurry. The slurry was passed into three sand mills in series and sanded to obtain a suspension. Taking the suspension prepared above, adding 25 kg of high temperature resistant dispersant and 10 kg of water-soluble dis-integrant into the suspension, shear stirring for 20 min to make the dispersant completely mix uniformly to obtain a water suspension slurry sample with solid content of 40%. The water suspension slurry is spray-dried into granules to obtain 50% pyraclostrobin dry suspension.

Embodiment 6: Preparation of 60% flonicamid-thiamethoxam dry suspension Formula composition: flonicamid original pesticide 20%; thiamethoxam original pesticide 40%; wetting agent (sulfosuccinate octyl sodium salt) 3%; high performance dispersant (polycarboxylic acid sodium salt dispersant) 5%; high temperature resistant dispersant (Reax 88B sodium lignosulfonate) 25%; defoamer (20% polydimethylsiloxane emulsion) 0.5%; dis-integrant (sodium sulfate) 6.5%. The preparation method is as follows: weighing 3 kg of wetting agent, 5kg of high performance dispersant, and 0.5kg of defoamer into a mixing vessel filled with 123 kg of water, stirring to dissolve; adding 20kg of thiamethoxam to the mixing vessel batch by batch, stirring the mixture into a uniform slurry, and the slurry was passed into three sand mills in series and sanded to obtain a suspension. Taking the above-prepared suspension, adding 25 kg of high temperature resistant dispersant and 6.5 kg of water soluble dis-integrant to the suspension, shear stirring for 20 min to make the dispersant completely mix uniformly to obtain a water suspension slurry sample with solid content of 45%. The water suspension slurry was spray-dried into granules to obtain 60% flonicamid-thiamethoxam dry suspension. In order to further illustrate the effect of the pesticide dry suspension prepared by the preparation method of the present application, the performance of the samples prepared in the above 6 embodiments are measured below to illustrate. From Table 1, it can be seen that the samples prepared in the 6 embodiments are all in water. It can quickly disintegrate without precipitation; the particle size (D90) is less than 5[m, and there is basically no obvious change in the particle size after being stored at 54°C for 14 days; the suspension rate is above 95%; which all meet the requirements of pesticide dry suspension.

Table 1

Intuitive effect of the D 9o Suspension D 9 o ( tm) Stored at 1bodiments Formula composition suspension dissolution ( tm) rate (%) 54C for 14days

Disintegrate without 1 50% pymetrozine DF 3.562 97 4.127 precipitation

55% pymetrozine-spirotetramat Disintegrate without 2 2.468 96 3.125 DF precipitation

55% pymetrozine-spirotetramat Disintegrate without 3 4.657 97 5.204 DF precipitation

Disintegrate without 4 70% imidacloprid DF 4.325 98 4.786 precipitation

Disintegrate without 5 50% pyraclostrobin DF 4.562 98 5.137 precipitation

60% flonicamid-thiamethoxam Disintegrate without 6 4.006 96 4.782 DF precipitation The above-mentioned embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skilled in the art should understand that they still can modify the technical solutions recorded the foregoing embodiments, or equivalently replace some of the technical features; such modifications or replacements do not cause the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application essentially, and should be included in within the protection scope of the present application.

Claims

CLAIM What is claimed is: 1. A preparation method of pesticide dry suspension, comprising the following steps: a. adding original pesticide, high-performance dispersant, wetting agent, defoamer, filler and water in sequence pro rata, and stir evenly to form a mixture; b. pulverizing the mixture obtained in step a coarsely in a shearing kettle with a high-speed shearing machine, and then finely pulverizing by a sand mill, and pulverizing to a particle size of 1 m- 5 m; c. adding the high temperature resistant dispersant and the water-soluble dis integrant to the suspension obtained in step b pro rata, after mixing, using the high speed shearing machine to fully stir the mixture in the shearing kettle, and then entering into the pressure spray dryer to spray, granulating to obtain finished pesticide dry suspension.
2. The preparation method of pesticide dry suspension according to claim 1, wherein the preparation method is suitable for original pesticide system which is difficult to prepare high solid content suspension slurry; the original pesticide system is any one of a low-melting original pesticide with a melting point lower than 80°C, a high-water soluble original pesticide with a water solubility greater than 0.5g/L, an original pesticide which are easy to form hydrogen bonds and water clusters with water.
3. The preparation method of pesticide dry suspension according to claim 2, wherein the low-melting-point original pesticide is pyraclostrobin original pesticide or difenoconazole original pesticide; the high water-soluble original pesticide is imidacloprid original pesticide, thiamethoxam original pesticide or flonicamid original pesticide; the original pesticide that easily forms hydrogen bonds and water clusters with water is the pymetrozine original pesticide.
4. The pesticide dry suspension prepared by the preparation method according to claim 1, wherein the formula composition is: original pesticide 50%~80%, high performance dispersant 2%~5%, wetting agent 1%~3%, high temperature resistant dispersant %~30%, water-soluble dis-integrant 0%~15%, defoamer 0.5%~1% and the rest is the filler.
5. The pesticide dry suspension according to claim 4, wherein the original pesticide is any one selected from the group consisting of the pymetrozine original pesticide, pyraclostrobin original pesticide, difenoconazole original pesticide, imidacloprid original pesticide, thiamethoxam original pesticide, and flonicamid original pesticide and a combination of any one of the pymetrozine original pesticide, pyraclostrobin original pesticide, difenoconazole original pesticide, imidacloprid original pesticide, thiamethoxam original pesticide, and flonicamid original pesticide with any one of the propineb original pesticide, zineb original pesticide, metiram original pesticide, Kresoxim-methyl original pesticide, trifloxystrobin original pesticide, thiophanate methyl original pesticide, tebuconazole original pesticide, hexaconazole original pesticide, and the spirotetramat original pesticide.
6. The pesticide dry suspension according to claim 4, wherein the high performance dispersant is at least one selected from the group consisting of polycarboxylate sodium salt, naphthalene sulfonate, alkyl naphthalene sulfonic acid formaldehyde condensate, di-alkyl succinic acid sulfonate, alkyl benzene sulfonate, fatty alcohol phosphate salts and lignosulfonates; the wetting agent is at least one selected from the group consisting of sodium lauryl sulfate, sodium dodecyl benzene sulfonate, sodium alkenyl sulfonate, sodium naphthalene sulfonate, sulfosuccinate sodium salt, alkyl succinic sulfonate; the high-temperature resistant dispersant is at least one selected from the group consisting of Borresperse NA, Ufoxane 3A, Ultraazine NA, Polyton H, Polyton 0, Reax 81A, Reax 82, Reax 83A, Reax 85A, Reax 88B, NSX-105, NSX-125, NSX-120, NSX 135 and D-30; the dis-integrant is at least one selected from the group consisting of potassium sulfate, sodium sulfate, ammonium sulfate, and urea; the filler is kaolin.