Pesticide composition and method for producing the same

Abstract

This invention belongs to the field of pesticide formulation technology, specifically relating to a wide-temperature-range pendimethalin water-in-oil emulsion and its production process. The wide-temperature-range pendimethalin water-in-oil emulsion, based on 100 parts by weight, comprises the following components: 20-35 parts pendimethalin technical grade, 15-30 parts organic solvent, 5-10 parts emulsifier, 3-6 parts stabilizer, 0.5-1 part antifreeze, 0.2-1 part preservative, 0.1-2.5 parts thickener, and the balance being water; the stabilizer consists of 12-hydroxystearic acid, a photodegradable agent, hydroxypropyl starch, and allyl grafted sorbitol. The production process involves first preparing allyl grafted sorbitol for later use, then preparing the required components into an oil phase and an aqueous phase, adding the aqueous phase to the oil phase and shearing emulsifying to finally obtain the wide-temperature-range pendimethalin water-in-oil emulsion. This invention, through improvements to the components of the pendimethalin water-in-oil emulsion, solves the problems of poor storage stability and low-temperature crystallization instability in traditional pendimethalin water-in-oil emulsions.

Description

Technical Field

[0001] This invention belongs to the field of pesticide formulation technology, specifically relating to a wide-temperature-range pendimethalin water-in-oil emulsion and its production process. Background Technology

[0002] Pendimethalin is a broad-spectrum, selective dinitroaniline herbicide that works by inhibiting cell division in the meristematic tissues of weed shoots and roots. It is primarily used to control annual grasses and some broadleaf weeds. Currently, pendimethalin is available in various formulations to suit different crops and application scenarios, such as oil-emulsions, water-emulsions, and microcapsule suspensions. Oil-emulsions are the most mature and widely used; however, they require large amounts of aromatic organic solvents, which have negative environmental impacts and pose health risks to applicators. Microcapsule suspensions are a newer formulation with long-lasting efficacy, good stability, and environmental friendliness; however, their high technological barriers and generally high production costs hinder their widespread adoption.

[0003] However, the water-in-oil formulation of pendimethalin pesticide has two main drawbacks. First, it has poor storage stability; during long-term storage and transportation at high temperatures, it is prone to stratification, oil separation, and Austronesian ripening. Second, it is unstable at low temperatures; when pendimethalin water-in-oil is stored or used at low temperatures, the entire emulsion freezes or precipitates a large number of crystals, which are difficult to restore even after returning to room temperature.

[0004] Chinese patent CN102047878A discloses a pendimethalin emulsion, the components of which and their mass percentages are as follows: pendimethalin technical grade 1-45%; solvent 1-20%; emulsifier 1-18%; thickener 0.1-6%; antifreeze 0-5%; antimicrobial agent 0-3%; defoamer 0.1-1.5%; appropriate amount of pH adjuster; and deionized water to 100%. The emulsifier is selected from one or more of the following: ethylene oxide-propylene oxide block copolymer, nonylphenol polyoxyethylene ether, alkylphenyl polyoxyethylene ether, triethanolamine salt of tri(1-phenylethyl)phenol polyoxyethylene ether phosphate monoester or a mixture of monoester and diester, polyoxyethylene sorbitan anhydride ester, alkylphenol polyoxyethylene ether, calcium dodecylbenzenesulfonate, phenethylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, and fatty alcohol polyoxyethylene ether.

[0005] This patent only adds emulsifiers and does not add other stabilizers. When stored for a long time in high or low temperature environments, a single emulsifier is difficult to maintain a dense and high-strength interfacial film at the oil-water interface. The emulsion droplets are prone to flocculation and aggregation, and problems such as stratification and oil separation are very likely to occur during storage. Summary of the Invention

[0006] The purpose of this invention is to provide a wide-temperature-range dimethyl pendimethalin water emulsion to solve the problems of poor storage stability and low-temperature crystallization instability of traditional dimethyl pendimethalin water emulsions; this invention also provides a production process for the wide-temperature-range dimethyl pendimethalin water emulsion.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The wide-temperature-range pendimethalin emulsion of the present invention, based on 100 parts by weight, comprises the following components: 20-35 parts pendimethalin technical grade, 15-30 parts organic solvent, 5-10 parts emulsifier, 3-6 parts stabilizer, 0.5-1 part antifreeze, 0.2-1 part preservative, 0.1-2.5 parts thickener, and the balance being water; the stabilizer is composed of 12-hydroxystearic acid, photodegradable agent, hydroxypropyl starch, and allyl grafted sorbitol.

[0008] in: The organic solvent is solvent oil; the emulsifier is one or more of fatty alcohol polyoxyethylene ether, polyoxyethylene lauryl ether carboxylic acid, fatty acid methyl ester sulfonate or monoalkyl ether phosphate potassium salt; the antifreeze is ethylene glycol or glycerol; the preservative is sodium benzoate or potassium sorbate; the thickener is one of xanthan gum, gum arabic or magnesium aluminum silicate; and the photodegrading agent is iron stearate.

[0009] In the stabilizer, the mass ratio of 12-hydroxystearic acid, photodegrading agent, hydroxypropyl starch and allyl grafted sorbitol is (60~120):(2.5~5):(35~50):(6~15).

[0010] The preparation process of the allyl-grafted sorbitol is as follows: S1. Mix the solvent, D-glucose, catalyst and water, then add 3-bromopropene and carry out the reaction under an inert atmosphere to obtain the crude product. S2. The crude product is further processed to obtain allyl-grafted sorbitol.

[0011] In S1, the ratio of solvent, D-glucose, catalyst, water and 3-bromopropene is (3500~4500):(1000~1200):(680~800):(720~900):3000, where solvent and water are in mL, and D-glucose, catalyst and 3-bromopropene are in g; the catalyst is tin powder and the solvent is anhydrous ethanol.

[0012] In S1, the heat preservation reaction temperature is 80~90℃, and the heat preservation reaction time is 5~10h.

[0013] In S2, the post-treatment involves filtering the crude product to remove the solid phase, then sequentially adding water for dilution, ethyl acetate for extraction, and vacuum concentration to the resulting liquid phase, wherein the mass ratio of water to solvent is (1~2.5):1, and the mass ratio of ethyl acetate to 3-bromopropene is (4~8):1.

[0014] The production process of the wide-temperature-range dimethyl pendimethalin water emulsion of the present invention is characterized by comprising the following steps: (1) Dimethomorph technical, 12-hydroxystearic acid, photodegrading agent, hydroxypropyl starch and organic solvent were mixed once, and then emulsifier was added and mixed twice to obtain an oil phase; water, allyl grafted sorbitol, antifreeze, preservative and thickener were mixed to obtain an aqueous phase; (2) While stirring, the aqueous phase is added to the oil phase, and then shear emulsification and filtration are performed to obtain a wide temperature range dimethyl pendimethalin water emulsion.

[0015] in: In step (1), the primary blending temperature is 20~40℃, the primary blending rate is 400~900rpm, the secondary blending temperature is 40~70℃, and the secondary blending rate is 600~900rpm.

[0016] In step (2), the stirring rate is 450~800 rpm and the addition time is 5~20 min; the shear emulsification rate is 2500~4000 rpm and the shear emulsification time is 5~30 min.

[0017] The beneficial effects of this invention are as follows: The hydroxypropylation of hydroxypropyl starch weakens the hydrogen bonds within the starch granules, effectively preventing the starch chains from recrystallizing. In nonpolar solvents, 12-hydroxystearic acid can interact with hydroxypropyl starch through intermolecular hydrogen bonds, allowing the long-chain macromolecules of hydroxypropyl starch to extend effectively. The hydroxypropyl segments of hydroxypropyl starch have good compatibility with the long alkyl chains of 12-hydroxystearic acid, while the hydrophilic hydroxyl groups can interact with the hydroxyl and carboxyl groups of 12-hydroxystearic acid to form a network structure that encapsulates dimethyl pendimethicone molecules.

[0018] This invention prepares allyl-grafted sorbitol. The allyl grafting introduces a hydrophobic structure, modulating the hydrophilicity and hydrophobicity of sorbitol and improving its compatibility at the oil-water interface. The polyhydroxy structure of the allyl-grafted sorbitol can guide the network structure to stack at the oil-water interface through hydrogen bonding with the emulsifier, thereby giving the network structure a certain stability and fully encapsulating dimethylpentylamine molecules. This inhibits the tendency of dimethylpentylamine molecules to migrate from the inside of the oil droplets to the interface under high temperature conditions, thus fundamentally inhibiting Austronesian ripening and droplet co-aggregation driven by interfacial energy and chemical potential difference. The mutual stacking of the network structure effectively inhibits low-temperature crystallization and prevents crystals from piercing the emulsifier interfacial film, fundamentally improving the long-term storage stability of dimethylpentylamine water-based emulsions in a wide temperature range from high to low temperatures.

[0019] Ferrous stearate can act as a photodegrading agent. When pesticides are applied, it gradually degrades hydroxypropyl starch under light, causing the network structure to disintegrate and promoting the release of active ingredients in pendimethalin emulsions. This avoids the problem of the traditional pendimethalin emulsion having to compromise between storage stability and release performance. On the other hand, the stearic acid segments in ferric stearate have good compatibility with the network structure, and compared with the network structure, ferric stearate has better fluidity. Its stearic acid segments can also play an anti-crystallization role, further inhibiting the formation of stable crystal lattices by pendimethalin molecules and thus reducing the risk of low-temperature crystallization. Detailed Implementation

[0020] The present invention will now be described and illustrated in detail with reference to the embodiments.

[0021] The raw materials used in the following examples and comparative examples are all commercially available products. Among them, 3-bromopropylene was provided by Nantong Runfeng Petrochemical Co., Ltd.; fatty alcohol polyoxyethylene ether, brand name AEO-9, was provided by Shandong Yukang Chemical Co., Ltd.; polyoxyethylene lauryl ether carboxylic acid was provided by Tianmen Hengchang Chemical Co., Ltd.; fatty acid methyl ester sulfonate was provided by Guangzhou Xiangmei Chemical Technology Co., Ltd.; monoalkyl ether phosphate potassium salt was provided by Shanghai Shengwei Chemical Raw Materials Co., Ltd.; and dimethyl pendimethalin technical grade, purity 95%, was provided by Jiangsu Yong'an Chemical Co., Ltd.

[0022] Example 1 Preparation of allyl-grafted sorbitol Add 4500mL of anhydrous ethanol to a clean reaction vessel, start stirring, add 1200g of D-glucose, 800g of tin powder and 800mL of distilled water, and after mixing evenly, pressurize with nitrogen gas, then add 3000g of 3-bromopropene, and heat to 80℃ under nitrogen protection, and then keep the reaction at this temperature for 10h.

[0023] After the reaction was completed, the product was cooled to room temperature to obtain a crude product. The crude product was filtered to remove the solid phase. 9000g of distilled water was added to the resulting liquid phase for dilution, and 12000g of ethyl acetate was added for extraction. The upper organic phase was removed by standing. The resulting aqueous phase was rotary evaporated until no obvious fraction flowed out to obtain allyl grafted sorbitol.

[0024] Preparation of wide-temperature-range pendimethalin water emulsion Weigh out the required raw materials for later use. The total mass of the required raw materials is 100 parts, each part being 100g. This includes 20 parts of pendimethalin technical grade, 15 parts of organic solvent (solvent oil), 7 parts of emulsifier (6 parts of polyoxyethylene lauryl ether carboxylic acid, 1 part of monoalkyl ether phosphate potassium salt), 3 parts of stabilizer, 1 part of antifreeze (glycerol), 0.8 parts of preservative (potassium sorbate), 0.1 parts of thickener (magnesium aluminum silicate), and the balance being water. In the stabilizer, the mass ratio of 12-hydroxystearic acid, photodegradable agent (ferric stearate), hydroxypropyl starch, and allyl grafted sorbitol is 60:5:50:12.

[0025] Dimethoprim technical, 12-hydroxystearic acid, photodegrading agent, hydroxypropyl starch and organic solvent were added to the No. 1 batching vessel. The temperature was set to 40℃ and the mixing speed was set to 750 rpm. The mixture was mixed until the material was evenly dispersed. Then, an emulsifier was added, the temperature was set to 70℃, and the secondary mixing speed was set to 900 rpm. The secondary mixing was carried out for 5 minutes to obtain the oil phase.

[0026] Water, allyl-grafted sorbitol, antifreeze, preservative, and thickener were added to the No. 2 batching vessel and stirred until the materials were evenly dispersed to obtain the aqueous phase.

[0027] The oil phase was transferred to a mixing vessel equipped with a shear emulsification device. The stirring speed was 800 rpm, and the aqueous phase was added to the oil phase while stirring. The addition time was 5 min. If the viscosity of the system changed abruptly during the addition, the remaining aqueous phase should be added at once. The shearing speed was set to 4000 rpm, and shearing was performed for 5 min to obtain an emulsion. The emulsion was filtered through a polypropylene filter to remove a small amount of impurities. After sampling and testing, it was filled to obtain a wide temperature range dimethyl pendimethalin water emulsion.

[0028] Example 2 Preparation of allyl-grafted sorbitol Add 3500 mL of anhydrous ethanol to a clean reaction vessel, start stirring, add 1000 g of D-glucose, 720 g of tin powder and 900 mL of distilled water, and after mixing evenly, pressurize with nitrogen gas, then add 3000 g of 3-bromopropene, and heat to 90 °C under nitrogen protection, and then keep the reaction at this temperature for 5 h.

[0029] After the reaction was completed, the product was cooled to room temperature to obtain a crude product. The crude product was filtered to remove the solid phase. 3500g of distilled water was added to the resulting liquid phase for dilution, and 24000g of ethyl acetate was added for extraction. The upper organic phase was removed by standing. The resulting aqueous phase was rotary evaporated until no obvious fraction flowed out to obtain allyl grafted sorbitol.

[0030] Preparation of wide-temperature-range pendimethalin water emulsion Weigh out the required raw materials for later use. The total number of raw materials required is 100 parts by weight, with each part being 100g. This includes 30 parts of pendimethalin technical grade, 30 parts of organic solvent (solvent oil), 10 parts of emulsifier (3 parts of fatty alcohol polyoxyethylene ether and 7 parts of fatty acid methyl ester sulfonate), 5 parts of stabilizer, 0.5 parts of antifreeze (glycerol), 0.2 parts of preservative (sodium benzoate), 1.5 parts of thickener (gum arabic), and the balance being water. In the stabilizer, the mass ratio of 12-hydroxystearic acid, photodegradable agent (ferric stearate), hydroxypropyl starch, and allyl grafted sorbitol is 90:2.5:35:15.

[0031] Dimethomorph technical, 12-hydroxystearic acid, photodegrading agent, hydroxypropyl starch and organic solvent were added to the No. 1 batching vessel. The temperature was set to 20℃ and the mixing speed was set to 900 rpm. The mixture was mixed until the material was evenly dispersed. Then, an emulsifier was added, the temperature was set to 50℃, and the secondary mixing speed was set to 600 rpm. The secondary mixing was carried out for 15 minutes to obtain the oil phase.

[0032] Water, allyl-grafted sorbitol, antifreeze, preservative, and thickener were added to the No. 2 batching vessel and stirred until the materials were evenly dispersed to obtain the aqueous phase.

[0033] The oil phase was transferred to a mixing vessel equipped with a shear emulsification device. The stirring speed was 650 rpm, and the aqueous phase was added to the oil phase while stirring. The addition time was 20 min. If the viscosity of the system changed abruptly during the addition, the remaining aqueous phase should be added at once. The shearing speed was set to 3000 rpm, and shearing was performed for 12 min to obtain an emulsion. The emulsion was filtered through a polypropylene filter to remove a small amount of impurities. After sampling and testing, it was filled to obtain a wide temperature range dimethyl pendimethalin water emulsion.

[0034] Example 3 Preparation of allyl-grafted sorbitol Add 4000 mL of anhydrous ethanol to a clean reaction vessel, start stirring, add 1100 g of D-glucose, 680 g of tin powder and 720 mL of distilled water, and after mixing evenly, pressurize with nitrogen gas, then add 3000 g of 3-bromopropene, and heat to 85 °C under nitrogen protection, and then keep the reaction at this temperature for 8 hours.

[0035] After the reaction was completed, the product was cooled to room temperature to obtain a crude product. The crude product was filtered to remove the solid phase. 3200g of distilled water was added to the resulting liquid phase for dilution, and 15000g of ethyl acetate was added for extraction. The upper organic phase was removed by standing. The resulting aqueous phase was rotary evaporated until no obvious fraction flowed out to obtain allyl grafted sorbitol.

[0036] Preparation of wide-temperature-range pendimethalin water emulsion Weigh out the required raw materials for later use. The total mass of the required raw materials is 100 parts, each part being 100g. This includes 35 parts of pendimethalin technical grade, 25 parts of organic solvent (solvent oil), 5 parts of emulsifier (2.5 parts of polyoxyethylene lauryl ether carboxylic acid and 2.5 parts of fatty acid methyl ester sulfonate), 6 parts of stabilizer, 0.8 parts of antifreeze (ethylene glycol), 1 part of preservative (sodium benzoate), 2.5 parts of thickener (xanthan gum), and the balance being water. In the stabilizer, the mass ratio of 12-hydroxystearic acid, photodegradable agent (ferric stearate), hydroxypropyl starch, and allyl grafted sorbitol is 120:4.2:45:6.

[0037] Dimethyl pendimethalin technical, 12-hydroxystearic acid, photodegrading agent, hydroxypropyl starch and organic solvent were added to the No. 1 batching vessel. The temperature was set to 30℃ and the mixing speed was set to 400 rpm. The mixture was mixed until the material was evenly dispersed. Then, an emulsifier was added. The temperature was set to 40℃ and the secondary mixing speed was set to 700 rpm. The secondary mixing was carried out for 10 minutes to obtain the oil phase.

[0038] Water, allyl-grafted sorbitol, antifreeze, preservative, and thickener were added to the No. 2 batching vessel and stirred until the materials were evenly dispersed to obtain the aqueous phase.

[0039] The oil phase was transferred to a mixing vessel equipped with a shear emulsification device. The stirring speed was 450 rpm, and the aqueous phase was added to the oil phase while stirring. The addition time was 15 min. If the viscosity of the system changed abruptly during the addition, the remaining aqueous phase should be added at once. The shearing speed was set to 2500 rpm, and shearing was performed for 30 min to obtain an emulsion. The emulsion was filtered through a polypropylene filter to remove a small amount of impurities. After sampling and testing, it was filled to obtain a wide temperature range dimethyl pendimethalin water emulsion.

[0040] Comparative Example 1 Without adding 12-hydroxystearic acid, the rest of the operation process and raw materials used are the same as in Example 1.

[0041] Comparative Example 2 Hydroxypropyl starch was not added, and the rest of the operation process and raw materials used were the same as in Example 1.

[0042] Comparative Example 3 Ferric stearate was not added, and the rest of the operation process and raw materials used were the same as in Example 1.

[0043] Comparative Example 4 Without adding allyl-grafted sorbitol, the rest of the operation process and raw materials used are the same as in Example 1.

[0044] Implementation effect evaluation Referring to the operating methods in HG / T 2467.9-2003 "Specifications for Writing Standards for Pesticide Water-in-Emulsions" and HG / T 2467.2-2003 "Specifications for Writing Standards for Pesticide Emulsifiable Oils", low-temperature storage stability tests and thermal storage stability tests were designed for the wide-temperature-range pendimethalin water-in-emulsions prepared in the embodiments and comparative examples of this invention.

[0045] Low temperature stability test: Transfer 100 mL of sample into a centrifuge tube and cool it to -5 ± 2 °C in a refrigerator. Maintain the centrifuge tube and its contents at -5 ± 2 °C for 1 hour, stirring every 15 minutes for 15 seconds. Return the centrifuge tube to the refrigerator and perform cold storage stability characterization by placing it at -5 °C ± 2 °C for 20 days and at -15 °C ± 2 °C for 30 days. The characterization method involves removing the centrifuge tube, allowing it to stand at room temperature for 6 hours, and observing for the appearance of layering, precipitation, crystallization, and oily precipitate to determine product homogeneity. Then, centrifuge for 15 minutes and record the volume of precipitate at the bottom of the tube. A precipitate volume not exceeding 0.25 mL is considered acceptable.

[0046] Thermal storage stability test: Transfer 60 mL of the sample, seal it, and place it in a constant temperature oven at 54℃±2℃ for 40 days. Remove it and cool it to room temperature, then observe whether there is any layering, precipitation, local turbidity, or oily precipitation.

[0047] The specific test results for pendimethalin emulsion are shown in Table 1.

[0048] Table 1. Test results of pendimethalin emulsion

[0049] As can be seen from Table 1: The wide-temperature-range pendimethalin water-in-oil emulsions prepared in Examples 1-3 of this invention all exhibit excellent wide-temperature-range stability, solving the technical problems of traditional pendimethalin water-in-oil emulsions, such as easy separation of oil layers during long-term high-temperature storage, easy crystallization instability at low temperatures, and inability to recover at room temperature. By forming a network structure through the combination of hydroxypropyl starch and 12-hydroxystearic acid fibrous structure, and guided by allyl grafted sorbitol, the stacked network structure can significantly improve the storage stability and low-temperature anti-crystallization performance of the pendimethalin water-in-oil emulsion. Finally, ferric stearate, as a photodegrading agent, also improves the flowability of the network structure, further enhancing its anti-crystallization effect.

[0050] When any one of the core components of the stabilizer, namely 12-hydroxystearic acid, hydroxypropyl starch, iron stearate, and allyl grafted sorbitol, was missing in Comparative Examples 1, 2, 3, and 4, the heat storage and low temperature stability of the products all decreased significantly, and all test indicators failed to meet the standard requirements. Without any one of the components, the network structure could not be formed or the full performance could not be achieved.

Claims

1. A wide temperature range pendimethalin aqueous emulsion characterized in that, Based on a mass fraction of 100 parts, it consists of the following components: 20-35 parts of pendimethalin technical grade, 15-30 parts of organic solvent, 5-10 parts of emulsifier, 3-6 parts of stabilizer, 0.5-1 part of antifreeze, 0.2-1 part of preservative, 0.1-2.5 parts of thickener, and the balance being water; the stabilizer is composed of 12-hydroxystearic acid, photodegradable agent, hydroxypropyl starch, and allyl grafted sorbitol.

2. Pendimethalin aqueous emulsion according to claim 1, characterized in that The organic solvent is solvent oil; the emulsifier is one or more of fatty alcohol polyoxyethylene ether, polyoxyethylene lauryl ether carboxylic acid, fatty acid methyl ester sulfonate or monoalkyl ether phosphate potassium salt; the antifreeze is ethylene glycol or glycerol; the preservative is sodium benzoate or potassium sorbate; the thickener is one of xanthan gum, gum arabic or magnesium aluminum silicate; and the photodegrading agent is iron stearate.

3. The wide temperature range pendimethalin aqueous emulsion according to claim 1, characterized in that, In the stabilizer, the mass ratio of 12-hydroxystearic acid, photodegrading agent, hydroxypropyl starch and allyl grafted sorbitol is (60~120):(2.5~5):(35~50):(6~15).

4. The wide temperature range pendimethalin aqueous emulsion according to claim 1, characterized in that, The preparation process of allyl-grafted sorbitol is as follows: S1. Mix the solvent, D-glucose, catalyst and water, then add 3-bromopropene and carry out the reaction under an inert atmosphere to obtain the crude product. S2. The crude product is further processed to obtain allyl-grafted sorbitol.

5. The wide temperature range pendimethalin aqueous emulsion according to claim 4, characterized in that, In S1, the ratio of solvent, D-glucose, catalyst, water and 3-bromopropene is (3500~4500):(1000~1200):(680~800):(720~900):3000, where solvent and water are in mL, and D-glucose, catalyst and 3-bromopropene are in g; the catalyst is tin powder and the solvent is anhydrous ethanol.

6. The wide temperature range pendimethalin aqueous emulsion according to claim 4, characterized in that, In S1, the heat preservation reaction temperature is 80~90℃, and the heat preservation reaction time is 5~10h.

7. The wide temperature range pendimethalin aqueous emulsion according to claim 4, characterized in that, In S2, the post-treatment involves filtering the crude product to remove the solid phase, then adding water for dilution, ethyl acetate for extraction, and vacuum concentration to the resulting liquid phase. The mass ratio of water to solvent is (1~2.5):1, and the mass ratio of ethyl acetate to 3-bromopropene is (4~8):

1.

8. A process for the production of the pendimethalin aqueous emulsion of any one of claims 1 to 7, characterized in that, Includes the following steps: (1) Dimethomorph technical, 12-hydroxystearic acid, photodegrading agent, hydroxypropyl starch and organic solvent were mixed once, and then emulsifier was added and mixed twice to obtain an oil phase; water, allyl grafted sorbitol, antifreeze, preservative and thickener were mixed to obtain an aqueous phase; (2) While stirring, the aqueous phase is added to the oil phase, and then shear emulsification and filtration are performed to obtain a wide temperature range dimethyl pendimethalin water emulsion.

9. The production process of pendimethalin aqueous emulsion according to claim 8, characterized by, In step (1), the primary blending temperature is 20~40℃ and the primary blending rate is 400~900rpm. The secondary blending temperature is 40~70℃ and the secondary blending rate is 600~900rpm.

10. The process for producing pendimethalin aqueous emulsion according to claim 8, characterized by, In step (2), the stirring rate is 450~800 rpm and the addition time is 5~20 min; the shear emulsification rate is 2500~4000 rpm and the shear emulsification time is 5~30 min.

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