High-stability pesticide suspending agent and preparation method thereof

Abstract

The invention provides a high-stability pesticide suspending agent and a preparation method thereof. The high-stability pesticide suspending agent is prepared from the following raw materials in parts by weight: 30 to 40 parts of pyraclostrobin, 10 to 12 parts of modified polycarboxylic acid particles, 15 to 20 parts of pyraclostrobin, 15 to 20 parts of fluopyram, 5 to 8 parts of synergist, 1 to 5 parts of emulsifier, 1 to 2 parts of thickening agent and 80 to 100 parts of deionized water. The preparation method of the stable pesticide suspending agent comprises the following steps: adding the pyraclostrobin, the modified polycarboxylic acid particles, the pyraclostrobin and the fluopyram into the deionized water, stirring and mixing, then adding the synergist, the emulsifier and the thickening agent, and uniformly mixing and stirring to obtain the stable pesticide suspending agent. The high-stability pesticide suspending agent is green, clean, high in stability and good in disease control effect, and has a good application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticide suspension concentrates, in particular to a high-stability pesticide suspension concentrate and a preparation method thereof. Background Art

[0002] Pesticide suspension concentrates are made by processing water-insoluble solid active ingredients of pesticides into fine particles (generally with an average particle size of less than 5μm). These particles are then dispersed and suspended in water or oil solvents by adding surfactants (wetting agents and dispersants) and other additives to form a stable suspension liquid product. High-quality suspension concentrates have small particle sizes, generally 1-3μm (90% particle size is less than 5μm), and a high suspension rate. Most suspension concentrates are diluted with water and then used as foliar sprays on crops, achieving uniform coverage of the crop target and maintaining high adhesion to the crop leaves. Generally speaking, for a particular herbicide used to control weeds on the same crop, its efficacy and long-lasting effect are superior to those of wettable powders, while its effectiveness for insecticides and fungicides is similar to that of emulsifiable concentrates. Therefore, in developed countries in Europe and the United States, suspension concentrates have long been the most basic and important product in pesticide formulations.

[0003] Suspension concentrates (SCs) are rapidly developing and widely used, with excellent results, both domestically and internationally due to their dust-free performance, low transdermal toxicity, high suspension efficiency, high bioactivity, low dosage, low toxicity to humans and animals, and low production costs. They are particularly favored by users both domestically and internationally. SCs are the fastest-growing water-based formulation, boasting the highest concentration of active pesticide ingredients, the most mature processing technology, safety for operators, users, and the environment, relatively low cost, and excellent market prospects.

[0004] However, some problems often encountered in the processing of pesticide suspension products include: delamination, caking, paste, crystallization, room temperature thickening, hot storage solidification, hot storage gelation (fluidity deterioration), and flocculation after hot storage, which seriously affect the packaging, application and efficacy of the product. In order to improve this type of problem of suspension, researchers have conducted extensive research. Patent CN104145983A discloses a dispersible oil suspension containing sulfoxaflor, which uses sulfoxaflor and tolfenpyrad or sulfoxaflor as active ingredients. It has the characteristics of environmental protection and good efficacy, but uses an oil solvent as a dispersant, which puts a lot of pressure on the environmental protection and harms the environmental ecosystem in the long term. Patent CN114773404B discloses a lignin dispersant with a high carboxyl content and its preparation and application in a nanopesticide suspension concentrate. Lignin, a solvent, and diethyl halomalonate are uniformly mixed and then irradiated with gamma rays to cause an etherification grafting reaction to join the diethyl malonate. The ester groups are then hydrolyzed into carboxyl groups under alkaline conditions to obtain a lignin pesticide dispersant. The reaction conditions are mild and the method is simple, but its dispersion effect is limited and its stability needs to be further improved. It also affects the efficacy of the suspension concentrate.

[0005] Therefore, it is necessary to provide a green, clean, highly stable, and effective pesticide suspension to meet actual needs. Summary of the Invention

[0007] In view of the problems existing in the prior art, the purpose of the present invention is to provide a green, clean, and highly stable pesticide suspension concentrate with good control effect, so as to better meet the needs of practical applications.

[0008] To achieve this object, the technical solution of the present invention is as follows:

[0009] The invention provides a high-stability pesticide suspension concentrate. The high-stability pesticide suspension concentrate comprises the following raw materials in parts by weight: 30-40 parts of pyraclostrobin fluopyram, 10-12 parts of modified polycarboxylic acid particles, 15-20 parts of pyraclostrobin, 15-20 parts of fluopyram, 5-8 parts of a synergist, 1-5 parts of an emulsifier, 1-2 parts of a thickener, and 80-100 parts of deionized water.

[0010] In some embodiments of the present invention, the method for preparing the modified polycarboxylic acid particles comprises the following steps:

[0011] (1) Add acrylonitrile and fuming sulfuric acid into a sealed reactor, mix to obtain a mixed solution, heat, add isobutylene, and keep the mixture for 2-3 hours. After the reaction is completed, filter and dry to obtain a powder for later use;

[0012] (2) dissolving the powder obtained in step (1) in a 20-25% by mass ethanol aqueous solution, adding activated carbon, stirring for 20-30 minutes, filtering, adding dichloromethane to obtain a filtrate for dissolution, stirring at a constant temperature for 1-1.5 hours, centrifuging, washing, and drying to a powder for later use;

[0013] (3) The powder and deionized water of step (2) are added to a reactor, and nitrogen is passed through the reactor after heating. Allyl polyoxyethylene ether, methacryloyloxyethyl trimethylammonium chloride and potassium persulfate solution are added continuously, and the reaction is carried out for 3-5 hours. The pH is adjusted to neutral, and the modified polycarboxylic acid particles are obtained after dialysis and drying.

[0014] In the preparation method of modified polycarboxylic acid particles of the present invention, the mass ratio of acrylonitrile to fuming sulfuric acid in step (1) is 3-6:1, the reaction temperature is 30-45° C., and the mass of isobutylene is 10-15% of that of acrylonitrile.

[0015] In the preparation method of modified polycarboxylic acid particles of the present invention, the mass of the activated carbon in step (2) is 3-5% of the ethanol aqueous solution, the mass of the ethanol aqueous solution is 1-1.5 times that of the powder, the temperature is 18-25° C., and the mass of the dichloromethane is 3-6 times that of the filtrate.

[0016] In the preparation method of modified polycarboxylic acid particles of the present invention, the mass of the allyl polyoxyethylene ether in step (3) is 10-15% of the powder obtained in step (2), and the heating temperature is 60-65° C.; the mass of the methacryloyloxyethyltrimethylammonium chloride is 2-2.5% of the total mass of the reactants, the mass of the potassium persulfate solution is 2-3% of the total mass of the reactants, and the concentration of the potassium persulfate solution is 20-40 g / L.

[0017] In some embodiments of the present invention, the emulsifier is selected from castor oil polyoxyethylene ether or calcium dodecylbenzenesulfonate.

[0018] In some embodiments of the present invention, the thickener is selected from at least one of polyvinyl alcohol, xanthan gum, and magnesium aluminum silicate.

[0019] In some embodiments of the present invention, the method for preparing the synergist comprises the following steps:

[0020] (1) Processing bamboo into powder, placing it in a cooking pot, adding sodium hydroxide solution for alkalization treatment at 100-105°C, cooling to room temperature to obtain a slurry, adding xylanase and water, and performing enzymolysis at a pH of 5-6 and a temperature of 60-65°C. After enzymolysis, cooling to room temperature, filtering to obtain a residue cake, drying and setting aside;

[0021] (2) adding the residue filter cake dried in step (1) into water, adjusting the pH to 9-10, adding sodium sulfite and ferric chloride, heating the reaction for 1-3 hours, collecting the product, and drying it into powder;

[0022] (3) Add the powder obtained in step (2), 1-chloroacetic acid, and chlorosulfonic acid into water, adjust the pH to 10-11, heat the reaction for 2-2.5 hours, and then spray dry to obtain a synergist.

[0023] In the preparation method of the synergist of the present invention, the time of the alkalization treatment in step (1) is 1-3 hours, the concentration of the sodium hydroxide solution is 5-7%, the mass of the sodium hydroxide solution is 1-5 times that of bamboo, the mass of the xylanase is 1-3% of that of bamboo, and the mass of the water is 30-50 times that of the xylanase.

[0024] In the preparation method of the synergist of the present invention, the mass of the sodium sulfite in step (2) is 0.4-0.6 times that of the residual filter cake, the mass of the ferric chloride is 5-10% of the sodium sulfite, and the reaction temperature is 100-120°C.

[0025] In the preparation method of the synergist of the present invention, the mass ratio of the powder to 1-chloroacetic acid in step (3) is 1:1-1.5, and the reaction temperature is 70-80°C.

[0026] Furthermore, a method for preparing a highly stable pesticide suspension comprises the following steps:

[0027] Add pyraclostrobin, modified polycarboxylic acid particles, pyraclostrobin and fluopyram into deionized water, stir and mix, then add synergist, emulsifier and thickener, and stir until evenly mixed.

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

[0029] The high-stability pesticide suspension provided by the present invention can effectively improve the dispersion and stabilization effect of the pesticide suspension system by using modified polycarboxylic acid particles and a synergist in the preparation of the pesticide suspension, can be stored for a long time, prevents the pesticide from settling, maintains the long-term stability of the pesticide, and has a good effect on disease prevention and control.

[0030] Among them, modified polycarboxylic acid particles are made from acrylonitrile, fuming sulfuric acid, and isobutylene, modified with allyl polyoxyethylene ether and methacryloyloxyethyl trimethylammonium chloride. They possess hydrophobic side chains, creating a steric hindrance effect that effectively improves the dispersibility of pesticide suspension concentrates. Separately, a synergist made from bamboo, from which lignin is extracted, grafted with sulfonate groups, and further modified with chlorosulfonic acid and 1-chloroacetic acid, exhibits excellent surface activity and dispersibility. When used in conjunction with modified polycarboxylic acid particles, they significantly improve the stability of the suspension concentrate while enhancing its adhesion and spread on plant and pest surfaces, improving its efficacy and holding potential. DETAILED DESCRIPTION

[0031] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following examples are examples of the present invention and are only used to illustrate the present invention, but not to limit the present invention. Without departing from the subject matter or scope of the present invention, other combinations and various improvements within the scope of the present invention may be made. In the following examples, the compounds and related reagents used can be purchased from the market, among which activated carbon was purchased from Zhengzhou Xingsen Activated Carbon Co., Ltd., methacryloyloxyethyl trimethylammonium chloride was purchased from Beijing Zeping Technology Co., Ltd., xylanase was purchased from Zhengzhou Longhai Xylanase Co., Ltd., and magnesium aluminum silicate was purchased from Shandong Kaizhuo Chemical Co., Ltd.

[0032] Preparation of modified polycarboxylic acid particles

[0033] A modified polycarboxylic acid particle, wherein the preparation method of the modified polycarboxylic acid particle comprises the following steps:

[0034] (1) 4 kg of acrylonitrile and 700 g of fuming sulfuric acid were added to a sealed reactor, mixed to obtain a mixed solution, heated to 45° C., added with 600 g of isobutylene, and kept warm for 2 h. After the reaction was completed, the mixture was filtered and dried to obtain a powder for later use;

[0035] (2) 200 g of the powder obtained in step (1) was dissolved in 200 g of a 25% ethanol aqueous solution, 6 g of activated carbon was added, and the mixture was stirred for 30 min. The mixture was filtered to obtain a filtrate, 1 kg of dichloromethane was added for dissolution, and the mixture was stirred at a constant temperature for 1.5 h. The mixture was centrifuged, washed, and dried to obtain a powder for later use.

[0036] (3) 104 g of the product of step (2) and 1 L of deionized water were added to a reactor, the temperature was raised to 65° C., nitrogen was passed through the reactor, and 11 g of allyl polyoxyethylene ether, 2.5 g of methacryloyloxyethyl trimethylammonium chloride, and 3 g of a 40 g / L potassium persulfate solution were added. The reaction was continued for 3 h. The pH was adjusted to neutral, the mixture was dialyzed, and then dried to obtain modified polycarboxylic acid particles.

[0037] Preparation of synergist

[0038] A synergist, wherein the preparation method of the synergist comprises the following steps:

[0039] (1) 1000 g of bamboo was processed into powder, placed in a cooking pot, added with 2 L of 7% sodium hydroxide solution and alkalized at 100 ° C for 3 h, cooled to room temperature to obtain a slurry, 30 g of xylanase and 90 g of water were added, and enzymolysis was carried out at a pH of 6 and a temperature of 65 ° C. After enzymolysis for 10 h, the temperature was cooled to room temperature, and the residue cake was filtered to obtain a filter cake, which was dried and set aside.

[0040] (2) Take 50g of the residual filter cake after drying in step (1) and add it to water, adjust the pH to 10, add 30g of sodium sulfite and 3g of ferric chloride, raise the temperature to 120℃ and react for 3h, collect the product and dry it into powder.

[0041] (3) 30 g of the powder obtained in step (2), 45 g of chlorosulfonic acid, and 45 g of 1-chloroacetic acid were added to 200 g of water, the pH was adjusted to 10, the temperature was raised to 80° C., the reaction was carried out for 2.5 h, and then spray-dried to obtain a synergist.

[0042] Example 1

[0043] A high-stability pesticide suspension concentrate comprises the following raw materials in parts by weight: 40 parts of pyraclostrobin, 12 parts of modified polycarboxylic acid particles, 20 parts of pyraclostrobin, 20 parts of fluopyram, 8 parts of a synergist, 5 parts of castor oil polyoxyethylene ether, 2 parts of magnesium aluminum silicate, and 100 parts of deionized water.

[0044] The preparation method of the high-stability pesticide suspension comprises the following steps:

[0045] Add pyraclostrobin, modified polycarboxylic acid particles, pyraclostrobin, and fluopyram into deionized water, stir and mix, then add the synergist, castor oil polyoxyethylene ether, and magnesium aluminum silicate, and stir until evenly mixed.

[0046] Example 2

[0047] A high-stability pesticide suspension concentrate comprises the following raw materials in parts by weight: 30 parts of pyraclostrobin, 10 parts of modified polycarboxylic acid particles, 20 parts of pyraclostrobin, 20 parts of fluopyram, 8 parts of a synergist, 5 parts of castor oil polyoxyethylene ether, 2 parts of magnesium aluminum silicate, and 100 parts of deionized water.

[0048] The preparation method of the high-stability pesticide suspension concentrate is the same as that in Example 1.

[0049] Example 3

[0050] A high-stability pesticide suspension concentrate comprises the following raw materials in parts by weight: 30 parts of pyraclostrobin, 10 parts of modified polycarboxylic acid particles, 15 parts of pyraclostrobin, 15 parts of fluopyram, 5 parts of a synergist, 1 part of castor oil polyoxyethylene ether, 1 part of magnesium aluminum silicate, and 100 parts of deionized water.

[0051] The preparation method of the high-stability pesticide suspension concentrate is the same as that in Example 1.

[0052] Comparative Example 1

[0053] The difference from Example 1 is that no modified polycarboxylic acid particles are added.

[0054] Comparative Example 2

[0055] The difference from Example 1 is that no synergist is added.

[0056] Comparative Example 3

[0057] The difference from Example 1 is that no modified polycarboxylic acid particles and synergist are added.

[0058] Comparative Example 4

[0059] The difference from Example 1 is that the modified polycarboxylic acid particles are replaced by dispersant D1002 (purchased from Beijing Hammock Chemical Technology Co., Ltd.).

[0060] The performance tests of the high stability pesticide suspension concentrates prepared in the examples and comparative examples were carried out. The results are shown in Table 1:

[0061] High temperature stability: The high-stability pesticide suspension prepared in each embodiment and comparative example was placed in a thermostat at 54°C. After 14 days of storage, the viscosity was tested using a viscometer, the average particle size was tested using a particle size analyzer, and the appearance was observed with the naked eye.

[0062] Room temperature stability: The high-stability pesticide suspension prepared in each embodiment and comparative example was placed in a thermostat at 25°C. After 24 months of storage, the viscosity was tested using a viscometer, the average particle size was tested using a particle size analyzer, and the appearance was observed with the naked eye.

[0063] Pesticide field efficacy test:

[0064] The high-stability pesticide suspension prepared in each example and comparative example was diluted 500 times and then sprayed on the rice field. On the 25th day after use, the rate of rice sheath blight diseased plants was counted.

[0065] Table 1

[0066]

[0067]

[0068] By comparing the test results of the embodiments in Table 1 with the comparative examples, it can be seen that the high-stability pesticide suspension concentrate provided by the present invention can effectively improve the dispersion and stabilization effect of the pesticide suspension concentrate system by using the modified polycarboxylic acid particles and the synergist in the preparation of the pesticide suspension concentrate, and can be stored for a long time without sedimentation of the pesticide, thereby maintaining the long-term stability of the pesticide suspension concentrate, and has good application prospects.

[0069] The above embodiments are only for illustrating the technical concept and features of the present invention. Its purpose is to enable people familiar with this technology to understand the content of the present invention and implement it. It cannot be used to limit the scope of protection of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A high stability pesticide suspension, characterized in that: The high-stability pesticide suspension comprises the following raw materials in parts by weight: 30-40 parts of pyraclostrobin, 10-12 parts of modified polycarboxylic acid particles, 15-20 parts of pyraclostrobin, 15-20 parts of fluopyram, 5-8 parts of synergist, 1-5 parts of emulsifier, 1-2 parts of thickener, and 80-100 parts of deionized water.

2. The high stability pesticide suspension according to claim 1, characterized in that: The preparation method of the modified polycarboxylic acid particles comprises the following steps: (1) adding acrylonitrile and fuming sulfuric acid into a sealed reaction kettle, mixing to obtain a mixed solution, heating, adding isobutylene, and keeping the temperature to react for 2-3 hours. After the reaction is completed, suction filtering is performed, and drying is performed to obtain a powder for standby use; (2) dissolving the powder obtained in step (1) in a 20-25% by mass ethanol aqueous solution, adding activated carbon, stirring for 20-30 min, filtering, adding dichloromethane to obtain a filtrate, stirring at a constant temperature for 1-1.5 h, centrifuging, washing, and drying into a powder for later use; (3) The powder obtained in step (2) and deionized water are added to a reactor, and after heating, nitrogen protection is introduced, and allyl polyoxyethylene ether, methacryloyloxyethyl trimethylammonium chloride and potassium persulfate solution are continuously added, and the reaction is carried out for 3-5 hours. The pH is adjusted to neutral, and the modified polycarboxylic acid particles are obtained after dialysis and drying.

3. The high stability pesticide suspension according to claim 2, characterized in that: In step (1), the mass ratio of acrylonitrile to oleum is 3-6:1, the reaction temperature is 30-45° C., and the mass of isobutylene is 10-15% of that of acrylonitrile.

4. The high stability pesticide suspension according to claim 2, characterized in that: In step (2), the mass of the activated carbon is 3-5% of the ethanol aqueous solution, and the temperature is 18-25°C.

5. The high stability pesticide suspension according to claim 2, characterized in that: The mass of the allyl polyoxyethylene ether in step (3) is 10-15% of the powder obtained in step (2), and the heating temperature is 60-65° C.; the mass of the methacryloyloxyethyl trimethylammonium chloride is 2-2.5% of the total mass of the reactants.

6. The high stability pesticide suspension according to claim 1, characterized in that: The emulsifier is selected from castor oil polyoxyethylene ether or calcium dodecylbenzene sulfonate.

7. The high stability pesticide suspension according to claim 1, characterized in that: The thickener is selected from at least one of polyvinyl alcohol, xanthan gum and magnesium aluminum silicate.

8. The high stability pesticide suspension according to claim 1, characterized in that: The preparation method of the synergist comprises the following steps: (1) Processing bamboo into powder, placing it in a cooking pot, adding sodium hydroxide solution to perform alkalinization treatment at 100-105° C., cooling to room temperature to obtain slurry, adding xylanase and water, performing enzymolysis at a pH of 5-6 and a temperature of 60-65° C., cooling to room temperature after enzymolysis, filtering to obtain a residue cake, drying and setting aside; (2) adding the residual filter cake after drying in step (1) into water, adjusting the pH to 9-10, adding sodium sulfite and ferric chloride, heating the reaction for 1-3 hours, collecting the product, and drying it into powder; (3) Take the powder obtained in step (2), 1-chloroacetic acid and chlorosulfonic acid and add them into water, adjust the pH to 10-11, heat and react for 2-2.5 hours, and then spray dry to obtain a synergist.

9. The high stability pesticide suspension according to claim 8, characterized in that: The time of the alkalinization treatment in step (1) is 1-3 hours, and the mass of the xylanase is 1-3% of the bamboo; the mass of the sodium sulfite in step (2) is 0.4-0.6 times that of the residual filter cake, and the reaction temperature is 100-120°C; the mass ratio of the powder to 1-chloroacetic acid in step (3) is 1:1-1.5, and the reaction temperature is 70-80°C.

10. A method for preparing a highly stable pesticide suspension according to any one of claims 1 to 9, characterized in that: The following steps are involved: Add pyraclostrobin, modified polycarboxylic acid particles, pyraclostrobin and fluopyram into deionized water, stir to mix, then add synergist, emulsifier and thickener, mix and stir evenly.

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