WO2020151377A1 - Preparation method for pesticide dry flowable - Google Patents

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

Method for preparing pesticide dry suspension Technical field

The invention belongs to the field of pesticide preparations, and particularly relates to a method for preparing a pesticide dry suspension.

Background technique

Pesticide dry suspension agent needs to be prepared by wet grinding to prepare suspension slurry, and then spray-dried to obtain 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 drug 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, which surrounds the surface of the original drug particles, which can ensure that the active ingredients do not agglomerate during the drying process and ensure product quality. Therefore, sodium lignosulfonate is the first choice for high temperature resistant dispersant.

At this stage, the wet pulverization process of pesticide dry suspension concentrates 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 fineness, the suspension slurry needs to be prepared to have a higher solid content. High solid content is essential for pulverization efficiency, energy saving during drying, and improved product granulation rate. Particle size has a positive effect. However, the increase in the 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 agent slurry with a high solid content and a lower viscosity. However, some low-melting, highly water-soluble technical materials are difficult to prepare high-content suspending agents. Sometimes the solid content of the suspended slurry has to be reduced to ensure fluidity. In addition, some pesticide technicals have no compatibility with lignin dispersant. The addition of lignin dispersant can not solve the dispersion problem, and it is not possible to obtain suspension slurry with high solid content. Only expensive high-temperature polymers can be used. Dispersant, increasing the difficulty of preparation and processing cost.

However, in wet grinding, a high-performance dispersant is used for high-speed grinding. After grinding, a dispersant with good heat resistance is added to shear mixing. It can not only improve the grinding efficiency and the solid content of the suspended slurry, but also ensure that the original drug does not agglomerate due to high-temperature spray drying.

technical problem

The embodiment of the present invention provides a method for preparing a pesticide dry suspension to help increase the solid content of the existing suspension slurry, reduce energy consumption in the spray drying process, and increase product particle size.

Technical solutions

The embodiments of the present invention are implemented in this way. In the first aspect, a method for preparing a pesticide dry suspension is provided. The specific steps are:

a. Add pesticide technical, high-performance dispersant, wetting agent, antifoaming agent, filler and water in sequence according to the proportion, 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 ground in a sand mill, and ground to a particle size of 1 μm ~ 5 μm;

c. Add the high temperature resistant dispersant and the water-soluble disintegrant to the suspension obtained in step b according to the proportion. 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 concentrate.

Beneficial effect

In the embodiment of the present invention, the preparation method can save energy to the utmost extent, and the high temperature resistant dispersant is not added during the grinding process, which can ensure the fluidity of the suspension agent and improve the grinding efficiency; and compared with mixed sand grinding, it can significantly improve The solid content of the suspended slurry can reduce energy consumption during spraying and granulation.

Embodiments of the invention

In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, but not to limit the present invention.

In order to help increase the solid content of the existing suspended slurry, reduce energy consumption in the spray drying process and increase product particle size.

The purpose of the present invention is to provide a pesticide dry suspension, the formula composition is:

Original drug 50%~80%, high performance dispersant 2%~5%, wetting agent 1%~3%, high temperature resistant dispersant 10%~30%, water-soluble disintegrant 0%~15%, defoaming 0.5%~1% of the agent and 100% of the filler.

In order to achieve the above-mentioned purpose of the invention, the present invention adopts the following technical solutions:

The invention provides a method for preparing a pesticide dry suspension, and the specific steps are:

a. Add pesticide technical, high-performance dispersant, wetting agent, antifoaming agent, filler and water in sequence according to the proportion, 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 ground in a sand mill, and ground to a particle size of 1 μm ~ 5 μm;

c. Add the high temperature resistant dispersant and the water-soluble disintegrant to the suspension obtained in step b according to the proportion. 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 concentrate.

The preparation method of the present invention is suitable for pesticide technical system that is difficult to prepare high solid content suspension slurry. The technical technical system is a low-melting technical drug with a melting point lower than 80°C, and a high-water-soluble drug with a water solubility greater than 0.5g/L. Either of the original drug, the original drug that easily forms hydrogen bonds and water clusters with water.

Preferably, the low melting point original drug is pyraclostrobin original drug or difenoconazole original drug.

Preferably, the high water-soluble original drug is imidacloprid, thiamethoxam, or flonicamid.

Preferably, the technical drug that easily forms hydrogen bonds and water clusters with water is pymetrozine technical.

In an embodiment, the pesticide technical can be pymetrozine technical, pyraclostrobin technical, difenoconazole technical, imidacloprid technical, thiamethoxam technical, and fluticoxamide technical Any one of the above-mentioned technical drugs and Prosenzin technical drugs, Zinc Zinc technical drugs, Zinc Zinc technical drugs, Zinc Zinc technical drugs, technical Kresoxim-methyl, trifloxystrobin technical materials, Thiophanate-methyl technical drugs, Ammonium A combination of any one of the hexaconazole original drug, the hexaconazole original drug, and the spirotetramat original drug.

The wetting agent is selected from sodium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium alkenyl sulfonate, sodium naphthalene sulfonate, sodium octyl sulfosuccinate, alkyl succinic acid sulfonic acid Any one or a mixture of two or more of the salts.

The high-performance dispersant is selected from polycarboxylate sodium salt, naphthalene sulfonate, alkyl naphthalene sulfonate formaldehyde condensate, dialkyl succinate sulfonate, alkyl benzene sulfonate, fatty alcohol phosphoric acid Any one or a mixture of two or more of ester salts and lignosulfonates. Through the selection of high-performance dispersant, the prepared suspension has good fluidity and low viscosity.

The high-temperature resistant dispersant is lignosulfonate of different specifications. In a specific embodiment, the lignosulfonate is selected from Borresperse NA, Ufoxane 3A, Ultraazine NA, and Westvaou's Polyton H, polyton O, Reax 81A, Reax 82, Reax 83A, Reax 85A, Reax 88B, any of NSX-105, NSX-125, NSX-120, NSX-135, D-30 in the Lignosol series of lignins One or two or more mixtures.

The disintegrant is selected from any one or a mixture of two or more of potassium sulfate, sodium sulfate, ammonium sulfate, and urea.

The filler is kaolin.

The preparation method of the present invention can save energy consumption to the utmost extent, does not add a high-temperature resistant dispersant during the grinding process, can ensure the fluidity of the suspension agent and improve the grinding efficiency; and compared with the mixed sand mill, it can significantly increase the solid content of the suspension slurry. It can reduce energy consumption in the process of spraying and granulating.

In order to illustrate the technical solution of the present invention, specific embodiments are used for description below.

Unless otherwise specified, all percentages in this specification refer to mass percentages.

Example one:

Preparation of 50% pymetrozine dry suspension

Formula composition: Pymetrozine technical 50%; wetting agent (sodium lauryl sulfate) 2%; high-performance dispersant (alkyl naphthalene sulfonic acid formaldehyde condensate sodium salt) 3%; high temperature resistant dispersant (Ultrazine NA model sodium lignosulfonate) 25%; defoamer (20% polydimethylsiloxane emulsion) 0.5%; disintegrant (potassium sulfate) 10%; filler (kaolin) to make up 100%.

The preparation method is as follows: weigh 2 Kg of wetting agent, 3 Kg of high-performance dispersant, and 0.5 Kg of defoamer into a stirred container filled with 150 kilograms of water, stir to dissolve; then add 50 Kg of pymetrozine, 9.5 One kilogram of filler (kaolin) is added to the mixing container batch by batch, and stirred into a uniform slurry. The slurry is passed into three sand mills in series and sanded to obtain a suspension. Take the pymetrozine suspension prepared above, add 25 Kg of high temperature resistant dispersant and 10 Kg of water-soluble disintegrant, shear and stir for 20 min to make the dispersant completely mix uniformly to obtain a 40% solid content water suspension slurry sample. The water suspension slurry was spray-dried into granules to obtain 50% pymetrozine dry suspension.

Embodiment two:

Preparation of 70% pymetrozine dry suspension

Formula composition: Pymetrozine technical 70%; wetting agent (sodium lauryl sulfate) 2%; high-performance dispersant (alkyl naphthalene sulfonic acid formaldehyde condensate sodium) 5%; high temperature resistant dispersant (Ultrazine NA Model sodium lignosulfonate) 20%; defoamer (20% polydimethylsiloxane emulsion) 0.5%; disintegrant (potassium sulfate) 2.5%.

The preparation method is as follows: weigh 2 Kg of wetting agent, 5 Kg of high-performance dispersant, and 0.5 Kg of defoamer into a stirred container filled with 150 kg of water and stir to dissolve; then add 70 Kg of pymetrozine technical substance in batches In the stirring container, stir into a uniform slurry, and pass the slurry into three sand mills connected in series, and sand to obtain a suspension agent. Take the pymetrozine suspension prepared above, add 20Kg of high-temperature resistant dispersant and 2.5Kg of water-soluble disintegrant, shear and stir for 20 min to make the dispersant completely mixed uniformly to obtain a 40% solid content water suspension slurry sample. The water suspension slurry was spray-dried into granules to obtain 70% pymetrozine dry suspension.

Example three:

Preparation of 55% Pymetrozine·Spirotetramat dry suspension

Formula composition: Pymetrozine technical 40%; Spirotetramat technical 15%; Wetting agent (sulfosuccinate octyl sodium salt) 2%; High performance dispersant (dialkyl succinate sulfonate) 3%; high temperature resistant dispersant (Ultrazine NA type sodium lignosulfonate) 25%; defoamer (20% polydimethylsiloxane emulsion) 0.5%; disintegrant (potassium sulfate) 10%; filler ( Kaolin) to make up 100%.

The preparation method is as follows: weigh 2 Kg of wetting agent, 3 Kg of high-performance dispersant, and 0.5 Kg of defoamer into a stirred container filled with 150 kg of water, stir to dissolve; then add 40 Kg of pymetrozine technical, 15 Kg of spirotetramat 4.5 kg of filler (kaolin) was added to the mixing vessel batch by batch, stirred into a uniform slurry, the slurry was passed into three sand mills in series, and sanded to obtain a suspension. Take the above-prepared suspending agent, add 25 Kg of high temperature resistant dispersant and 10 Kg of water-soluble disintegrant, shear and stir for 20 min to make the dispersant completely mixed uniformly to obtain a 40% solid content water suspension slurry sample. The water suspension slurry was spray-dried into granules to obtain 55% pymetrozine·spirobethin dry suspension.

Embodiment four:

Preparation of 70% imidacloprid dry suspension

Formulation composition: 70% imidacloprid original drug; wetting agent (sodium naphthalenesulfonate) 2%; high-performance dispersant (polycarboxylate sodium salt dispersant) 3%; high temperature resistant dispersant (Reax 81A sodium lignosulfonate) ) 20%; defoamer (20% polydimethylsiloxane emulsion) 0.5%; disintegrant (potassium sulfate) 4.5%.

Preparation method: Weigh 2 Kg of wetting agent, 3 Kg of high-performance dispersant, and 0.5 Kg of defoamer into a stirred container with 82Kg of water, stir to dissolve; then add 70 Kg of imidacloprid original drug into the stirred container one by one , Stir it into a uniform slurry, pass this slurry into three sand mills connected in series, and sand to obtain a suspending agent. Take the above-prepared imidacloprid suspension and add 20 Kg high temperature resistant dispersant and 4.5 Kg water-soluble disintegrant was sheared and stirred for 20 minutes to make the dispersant completely mixed uniformly to obtain a 55% solid content water suspension slurry sample. The water suspension slurry was spray-dried into granules to obtain 70% imidacloprid dry suspension.

Embodiment five:

Preparation of 50% pyraclostrobin dry suspension

Formula composition: pyraclostrobin technical 50%; wetting agent (naphthalenesulfonate sodium salt) 3%; high performance dispersant (alkyl naphthalene sulfonic acid formaldehyde condensate) 5%; high temperature resistant dispersant (polyton H Model sodium lignosulfonate) 25%; defoamer (20% polydimethylsiloxane emulsion) 0.5%; disintegrant (urea) 10%; filler (kaolin) to make up 100%.

Preparation method: Weigh 3 Kg of wetting agent, 5 Kg of high-performance dispersant, and 0.5 Kg of defoamer into a stirred container filled with 150Kg of water, stir to dissolve; then add 50 Kg of pyraclostrobin technical and 6.5 One kilogram of filler (kaolin) is added to the mixing container batch by batch, and stirred into a uniform slurry. The slurry is passed into three sand mills in series and sanded to obtain a suspension. Take the above-prepared suspending agent, add 25 Kg of high temperature resistant dispersant and 10 Kg of water-soluble disintegrant, shear and stir for 20 min to make the dispersant completely mixed uniformly to obtain a 40% solid content water suspension slurry sample. The water suspension slurry was spray-dried into granules to obtain 50% pyraclostrobin dry suspension.

Embodiment 6:

Preparation of 60% Flonicamid•thiamethoxam dry suspension

Formula composition: Flonicamid technical 20%; Thiamethoxam technical 40%; Wetting agent (Sulfosuccinate sodium salt) 3%; High performance dispersant (Polycarboxylate sodium salt dispersant) 5%; High temperature resistant dispersant (Reax 88B model sodium lignosulfonate) 25%; defoamer (20% polydimethylsiloxane emulsion) 0.5%; disintegrant (sodium sulfate) 6.5%.

The preparation method is as follows: Weigh 3 Kg wetting agent, 5Kg high-performance dispersant, 0.5Kg defoamer into a stirred container filled with 123 Kg of water, stir and dissolve; Kg of thiamethoxam was added to the stirring vessel batch by batch, stirred into a uniform slurry, and the slurry was passed into three sand mills connected in series and sanded to obtain a suspension. Take the above-prepared suspending agent, add 25 Kg of high temperature resistant dispersant and 6.5 Kg of water-soluble disintegrant, shear and stir for 20 minutes to make the dispersant completely mix uniformly to obtain a 45% solid content water suspension slurry sample. 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 invention, the performance of the samples prepared in the above 6 examples is measured below to illustrate. From Table 1, it can be seen that the samples prepared in the 6 examples are all in water. It can disintegrate quickly without precipitation; the particle size (D90) is less than 5μm, 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%; both meet the performance requirements of pesticide dry suspension.

Table 1

Example	Formula	Intuitive effect of preparation dissolution	D90 (μm)	Suspension rate (%)	D90 (μm) after heat storage at 54℃ for 14 days
1	50% pymetrozine DF	Disintegrate quickly without precipitation	3.562	97	4.127
2	70% pymetrozine DF	Disintegrate quickly without precipitation	2.468	96	3.125
3	55% Pymetrozine·Spirotetramat DF	Disintegrate quickly without precipitation	4.657	97	5.204
4	70% imidacloprid DF	Disintegrate quickly without precipitation	4.325	98	4.786
5	50% Pyraclostrobin DF	Disintegrate quickly without precipitation	4.562	98	5.137
6	60% Flonicamid•thiamethoxam DF	Disintegrate quickly without precipitation	4.006	96	4.782

The above-mentioned embodiments are only used to illustrate the technical solutions of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it can still implement the foregoing The technical solutions recorded in the examples are modified, or some of the technical features are equivalently replaced; these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in Within the protection scope of the present invention.

Claims (6)

1. A method for preparing a pesticide dry suspension is characterized in that the specific steps are:

   a. Add pesticide technical, high-performance dispersant, wetting agent, antifoaming agent, filler and water in sequence according to the proportion, 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 ground in a sand mill, and ground to a particle size of 1 μm ~ 5 μm;

   c. Add the high temperature resistant dispersant and the water-soluble disintegrant to the suspension obtained in step b according to the proportion. 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 concentrate.
2. The method for preparing a pesticide dry suspension concentrate according to claim 1, wherein the method is used for preparing a technical technical system with a high content of suspension agent that is difficult;

   The original drug system is any one of a low-melting original drug with a melting point lower than 80° C., a highly water-soluble original drug with a water solubility greater than 0.5 g/L, and an original drug that easily forms hydrogen bonds and water clusters with water.
3. The method for preparing a pesticide dry suspension according to claim 2, wherein the low-melting-point original drug is pyraclostrobin original drug or difenoconazole original drug;

   The high water-soluble original drug is imidacloprid, thiamethoxam, or flonicamid;

   The original drug of pymetrozine that easily forms hydrogen bonds and water clusters with water.
4. The pesticide dry suspension prepared by the preparation method of claim 1, wherein the formula is composed of: 50% to 80% of the original drug, 2% to 5% of the high performance dispersant, and 1% to 3% of the wetting agent , High temperature resistant dispersant 10%~30%, water-soluble disintegrant 0%~15%, defoaming agent 0.5%~1%, filling 100%.
5. The pesticide dry suspension of claim 4, wherein the pesticide technical is selected from the group consisting of pymetrozine technical, pyraclostrobin technical, difenoconazole technical, imidacloprid technical, and Any one of the original drug of oxazin and the original drug of flonicamid; and/or

   The above-mentioned original medicines are compatible with Prosenzin technical, Zinc Zinc technical, Zinc Zinc technical, technical Kresoxim-methyl, trifloxystrobin technical, Thiophanate-methyl technical, Tebuconazole technical, A combination of any one of the hexaconazole technical drug and the spirotetramat technical drug.
6. The pesticide dry suspension agent of claim 4, wherein the high-performance dispersant is selected from the group consisting of sodium polycarboxylate, naphthalene sulfonate, alkylnaphthalenesulfonic acid formaldehyde condensate, dialkyl succinic acid One or a mixture of two or more of sulfonates, alkylbenzene sulfonates, fatty alcohol phosphate ester salts, and lignosulfonates;

   The wetting agent is selected from sodium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium alkenyl sulfonate, sodium naphthalenesulfonate, sodium octyl sulfosuccinate, alkyl succinic acid sulfonic acid One or a mixture of two or more kinds of salt;

   The high temperature resistant dispersant is selected from Borresperse NA, Ufoxane 3A, Ultrazine NA, polyton H, polyton O, Reax 81A, Reax 82, Reax 83A, Reax 85A, Reax 88B, NSX-105, NSX-125, NSX-120, NSX-135, D-30 One or more mixtures;

   The water-soluble disintegrant is selected from one or a mixture of two or more of potassium sulfate, sodium sulfate, ammonium sulfate, and urea;

   The filler is kaolin.