A block polyether emulsifier and its application in pesticides

Abstract

The present invention relates to the application field of polyether emulsifiers, specifically a block polyether emulsifier and its application in pesticides. The present invention mainly synthesizes isomeric polyols, epoxides, end-capping agents and catalysts, wherein the isomeric polyols are used as initiators, and the epoxides are used as ring-opening adducts to carry out regular block addition reactions with low-carbon alcohols to eventually form high-molecular block polyethers. Since the multiple block polyether chains formed by the reaction contain abundant oxygen, they can generate hydrogen bonds with active hydrogen, and the isomeric spatial structure is more complex, so that the block polyether forms a more stable spatial structure with active ingredients and impurities. After the end-capping operation, the structural block polyether can be used as an emulsifier to not only improve the physical and chemical properties of the pesticide preparation and enhance the efficacy, but also make the product more fluid, have better wetting permeability and lower foaming, thereby effectively improving the quality of the product.

Description

Technical Field

[0001] The present invention relates to the application field of polyether emulsifiers, in particular to a block polyether emulsifier and application thereof in pesticides. Background Art

[0002] Block polyethers are a key component of nonionic surfactants, primarily used as emulsifiers, defoamers, detergents, and quenching agents. Generally, block polyethers are composed of hydrophobic polyoxypropylene groups and hydrophilic polyoxyethylene groups. Depending on the synthesis method, block polyethers are primarily categorized as either regular copolymers or random co-polymers. Due to the specific structure, composition, and arrangement of hydrophilic and hydrophobic groups, block polyethers form a unique spatial arrangement during the emulsification process, often exhibiting excellent emulsification, solubilization, and enhanced stability properties. These block polyethers have significant potential for application in pesticide emulsification.

[0003] With the advancement of green and environmentally friendly agriculture, agricultural production has placed higher demands on pesticide use. Improving pesticide efficiency and reducing the use of toxic and hazardous substances in pesticide formulations have become major trends. Traditional pesticide formulations contain a large number of prohibited and restricted solvents and emulsifiers. With updated formulations and formulas, the residual impurities and solvents in the original pesticide have changed, making it difficult to dissolve in common solvents and water. When mixed with traditional pesticide emulsifiers, it continues to cause flocculation and precipitation. Segmented polyethers, with their rich structure and easy degradation, can not only effectively solve this problem but also reduce the amount of polar solvents required when formulating biopesticide mother liquors, thereby improving the stability of stable formulations. Furthermore, the unique spatial structure of segmented polyethers improves miscibility with aqueous pesticide formulations, provides excellent storage stability, and resists degradation of defoaming effects, making them a viable alternative to traditional pesticide defoamers.

[0004] Foreign countries have focused on block polyethers for many years, and have launched a number of products. However, domestic manufacturers are still in the early stages of polyether research and development, making it difficult to put them into practical application. Due to the high prices of foreign products and insufficient domestic research and development, block polyethers have not been widely used in pesticide adjuvants in China. Therefore, it is crucial to study the synthesis of block polyethers and their application in pesticides, precisely utilizing the complex spatial structure of block polyethers to address specific pesticide formulation issues. Summary of the Invention

[0005] The object of the present invention is to provide a block polyether emulsifier and its application in pesticides to solve the problems raised in the above background technology.

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

[0007] A block polyether emulsifier comprises the following steps:

[0008] Step (1): adding isomeric polyols having active hydrogen and catalyst I into a reactor, heating the reactor and then evacuating the reactor, bubbling nitrogen for 45 to 60 minutes, and maintaining a constant temperature and vacuum state at 120 to 140° C. for dehydration;

[0009] Step (2): introducing propylene oxide, maintaining a certain pressure, and after the addition reaction begins, controlling the temperature, pressure and stirring speed, and continuously feeding until the predetermined amount of material is introduced; after aging, vacuuming for 30 minutes, and stabilizing and refining the reaction product;

[0010] Step (3): After the reactor is heated to 140° C., ethylene oxide is introduced, and the pressure, temperature and stirring speed are controlled. The feed is continuously added until the predetermined amount of ethylene oxide is completed, followed by aging. After the pressure in the reactor is stabilized, non-condensable gas and unreacted epoxide are removed by vacuum suction, and then the reaction product, uncapped block polyether, is obtained by washing and filtering.

[0011] Step (4): mixing the amino acid with aqueous hydrochloric acid solution, heating and dissolving the mixture, transferring the mixture to a reactor, stirring evenly, introducing nitrogen, and controlling the reaction temperature; washing with anhydrous ethanol, filtering, vacuum distillation, and drying to obtain a reddish-brown transparent viscous component A;

[0012] Step (5): the uncapped block polyether obtained as the reaction product according to steps (1) to (3) is placed in a reaction kettle with sodium methoxide, the reaction is heated and then vacuumed to remove impurities, the mixture is continuously stirred, the temperature is lowered after sufficient reaction, and the capping reagent is added, and the temperature is gradually raised to maintain the pressure in the kettle for reaction; after the reaction is completed, the volatile impurity components are removed by vacuuming, the temperature is lowered, and the material is discharged;

[0013] Step (6): add deionized phosphoric acid solution, stir and react at 90°C for 1 hour, wash and dehydrate, and filter to obtain reddish brown transparent viscous component B.

[0014] Step (7): Mix component A, component B, and component C to obtain a block polyether emulsifier.

[0015] Furthermore, in step (1), the isomeric polyols are 1,2-propylene glycol and 2,3-butanediol, preferably 2,3-butanediol; the catalyst I is at least one of an alkaline catalyst, a phosphazene catalyst or a double metal cyanide complex, preferably tetrakis[tris(dimethylamino)phosphoranylideneamino]phosphorus fluoride, and the addition amount is 0.02 to 1% of the total mass of the isomeric polyols.

[0016] Furthermore, in step (2), the pressure is maintained at 0.2-0.3 MPa after the introduction of oxime; during the addition reaction, the pressure is controlled at 0-0.2 MPa, the temperature is controlled at 140±5°C, and the stirring speed is controlled at 450-600 rpm; and the aging time is 1-2 h.

[0017] Furthermore, in step (3), the pressure is controlled at 0-0.2 MPa, the temperature is controlled at 140±5°C, the stirring speed is controlled at 350-450 rpm; the aging time is 2-3 h, and the vacuum suction time is 30 min;

[0018] Furthermore, in step (4), the amino acid is any one of glycine, threonine, serine, glutamic acid, and aspartic acid, preferably glycine; the mass concentration of the hydrochloric acid aqueous solution is 2%, and the mixing ratio of the amino acid and the hydrochloric acid aqueous solution is 0.4 mol / 100 mL; the molar ratio of the amino acid to the uncapped block polyether of the reaction product in step (3) is 2.1:1; the reaction temperature is 90° C., and the reaction time is 10 min.

[0019] Furthermore, in step (5), the reaction temperature of the blocked polyether and sodium methoxide is 120°C; the stirring time is 1 to 2 hours; the capping agent is monochloromethane, monochlorooctane, or lauryl chloride, among which lauryl chloride is preferred; the capping reaction temperature is 120°C, the pressure is 0.3 to 0.4 MPa, and the reaction time is 2 to 3 hours; and the discharge temperature is 60°C.

[0020] Furthermore, in step (6), a 5% deionized phosphoric acid solution is added to adjust the pH to 4-7, and the moisture content after dehydration is 0-0.5%.

[0021] Furthermore, in step (7), the content of each component of the block polyether emulsifier is, by weight, 10-30% component A, 5-10% component B, and 60-85% component C;

[0022] Furthermore, the component A is:

[0023] CH3CH[OCH2CH(CH3)] x (OCH2CH2) y OR2

[0024] |

[0025] R1CH[OCH2CH(CH3)] x (OCH2CH2) y OR2;

[0026] Wherein, R1 is H or CH3; R2 is one of COCH2NH2, COCH(NH2)CHOHCH3, COCH(NH2)CH2OH, COCH2CH(NH2)COOH, COCH2CH2CH(NH2)COOH; the molecular weight of component A is 2500-3500, 2≤x≤10, 15≤y≤40, x:y=(1:3)~(1:11), and the HLB value is 14~18;

[0027] Further, the component B is:

[0028] CH3CH[OCH2CH(CH3)] m (OCH2CH2) n OR3

[0029] |

[0030] R1CH[OCH2CH(CH3)] m (OCH2CH2) n OR3;

[0031] Wherein, R1 is H or CH3, R3 is CH3, CH2(CH2)6CH3, CH2(CH2) 10 One of CH3; component B has a molecular weight of 1800-2500, 8≤m≤10, 1≤n≤2, m:n=9:1, and an HLB value of 1-3;

[0032] Furthermore, the component C is one or more of alkyl glucosides, betaine, alkylphenol polyoxyethylene ether, castor oil polyoxyethylene ether, penetrant T, tallow amine polyoxyethylene ether, and cationic surfactants.

[0033] Compared with the prior art, the present invention achieves the following beneficial effects: The present invention synthesizes isomeric polyols, epoxides, end-capping agents, and catalysts. The isomeric polyols serve as initiators, providing free radicals in the reaction to initiate the synthesis reaction. The epoxides, as ring-opening adducts, undergo a regular block addition reaction with lower alcohols, ultimately forming a high-molecular-weight segmented polyether. The multiple segmented polyether chains formed by the reaction with the isomeric polyols contain abundant oxygen, which can form hydrogen bonds with active hydrogens. Furthermore, the isomeric spatial structure is more complex, allowing the segmented polyether to form a more stable spatial structure with active ingredients and impurities. After the end-capping operation, different products, Component A and Component B, are obtained. The presence of carboxyl groups on the amino acid groups in Component A gives the amino groups a positive charge, allowing them to form a variety of structures with many active ingredients. Furthermore, the surfaces of plant leaves, insects, and microorganisms are all negatively charged. This segmented polyether structure not only improves the physical and chemical properties of the preparation but also enhances its efficacy. Component B, on the other hand, can improve product performance toward better fluidity, improved wetting and permeability, and lower foaming, effectively improving product quality. DETAILED DESCRIPTION

[0034] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0035] In the following examples, the main materials and their sources are as follows:

[0036] 2,3-Butanediol (CAS: 513-85-9, 98%, Aladdin); Ethylene oxide (CAS: 75-21-8, Yangzi Petrochemical); Propylene oxide (CAS: 75-56-9, Dow Chemical Company, Saudi Arabia); Glycine (CAS: 56-40-6, 99%, Henan Zongchuang Food Ingredients Co., Ltd.); Hydrochloric acid (CAS: 7647-04-0, 37%, Yangzhou Huafu Chemical Co., Ltd.); Sodium methoxide (CAS: 124-41-4, 97%, Aladdin); Anhydrous ethanol (CAS: 64-17-5, 99.9%, Jinan Bada Chemical); Tetrakis(tris(dimethylamino)phosphoranylideneamino)phosphonium fluoride (CAS: 156206-56-3, Anaiji Chemical); Phosphoric acid (CAS: 7664-38-2, 85%, Chuandong Chemical); Benzene Dasong raw powder (Wuhan Rongcan Biotechnology); sodium hydroxide (CAS: 1310-73-2, Aladdin); cellulose acetate butyrate (CAS: 9004-36-8, Xiya Chemical Technology); lauryl chloride (CAS: 112-52-7, Guangzhou Yuanda New Materials Co., Ltd.); BY-125 (Nanjing Taihua Chemical Co., Ltd.); APG (Kaiqing Chemical); sodium di-sec-octyl maleate sulfonate (CAS: 1639-66-3, Nanjing Taihua Chemical Co., Ltd.); OP-8 (Nanjing Taihua Chemical Co., Ltd.); fatty amide propyl dimethylammonium chloride (Shanghai Chuxing Chemical); thiamethoxam technical (Wuhan Proloff Biotechnology); DMF (CAS: 68-12-2, Aladdin); matrine ointment (Chengdu Desite Biotechnology); silicone defoamer (Nanjing Aolifeng Defoamer NY001).

[0037] Example 1

[0038] Prepare component A.

[0039] 45g of 2,3-butanediol and 0.009g of tetrakis[tris(dimethylamino)phosphoranylideneamino]phosphonium fluoride were added to a reactor. The reactor was heated to 120°C, evacuated, and nitrogen was introduced for 45 minutes. Dehydration was then performed at a constant temperature of 120°C while maintaining a vacuum state. 406g of propylene oxide was slowly introduced until the desired amount of propylene oxide was introduced. The reaction mixture was aged for 1 hour, evacuated for 30 minutes, and the reaction product was stabilized and refined. The reactor was heated and maintained at 140±5°C, with a pressure of 0.15MPa and a stirring speed of 350rpm. 1188g of ethylene oxide was continuously introduced for an addition reaction. The reaction mixture was then aged for 2 hours. After the pressure in the reactor stabilized, the mixture was vacuumed to remove non-condensable gases and unreacted epoxide. The block polyether was then washed and filtered to obtain the product. 48 g of glycine was mixed with 160 ml of a 2% aqueous hydrochloric acid solution, heated to dissolve, and then transferred to a reactor. The mixture was evenly mixed with 1 kg of block polyether and nitrogen was introduced. The reaction temperature was controlled at 90°C for 10 min. The mixture was washed with anhydrous ethanol and filtered. The ethanol solution in the system was removed by vacuum distillation. The mixture was then transferred to a vacuum constant temperature drying oven at 60°C and dried for 6 h to obtain component A.

[0040] CH3CH[OCH2CH(CH3)]7(OCH2CH2) 27 OCOCH2NH2

[0041] |

[0042] CH3CH[OCH2CH(CH3)]7(OCH2CH2) 27 OCOCH2NH2.

[0043] Example 2

[0044] Prepare component B.

[0045] 90g of 2,3-butanediol, 0.18g of tetrakis[tris(dimethylamino)phosphoranylideneamino]phosphorus fluoride, 1044g of propylene oxide and 88g of ethylene oxide were reacted according to the method described in Example 1 to obtain an uncapped block polyether; 1kg of the block polyether and 4g of sodium methoxide were placed in a reactor, heated to 120°C for reaction, vacuum suction was used to remove impurities, and stirring was continued for 1.5h. After sufficient reaction, the temperature was lowered to 60°C and 338g of lauryl chloride was added and the temperature was gradually raised to 120°C, while maintaining the pressure in the reactor at about 0.35Mpa and reacting for 2h; after the reaction was completed, volatile impurity components were removed by vacuum suction, and the material was cooled and discharged; a 5% mass concentration of deionized phosphoric acid solution was added, stirred at 90°C for reaction for 1h, washed, and dehydrated to 0.5%, washed, and filtered to obtain a reddish-brown transparent viscous component B:

[0046] CH3CH[OCH2CH(CH3)]9OCH2CH2OCH2(CH2) 10 CH3

[0047] |

[0048] CH3CH[OCH2CH(CH3)]9OCH2CH2OCH2(CH2) 10 CH3.

[0049] Example 3

[0050] 7.8 g of 95% NaOH and 40.66 g of deionized water were uniformly mixed, and 41.54 g of 96.3% bentazon raw powder was added. The mixture was stirred at a temperature of 50°C to 60°C and normal pressure at a stirring speed of 450 rpm until the reaction was complete. The mixture was kept warm and stirred for 1 hour to obtain a 40% bentazon aqueous solution. 2 g of component A in Example 1, 0.8 g of component B in Example 2, and 7.2 g of component C1 were added to the 40% bentazon aqueous solution and stirred uniformly. The stabilizing effect of the mixed solution on floccules in the 40% bentazon aqueous solution was examined.

[0051] Among them, in component C1, betaine is 35% cellulose acetate butyrate, castor oil polyoxyethylene ether is BY-125, alkyl glycoside is specifically 50% APG, and penetrant T is 65% sodium di-sec-octyl maleate sulfonate. The content of each component, by weight:

[0052]

[0053] Example 4

[0054] The amount of polar solvent used, precipitation and foaming of the preparation were investigated.

[0055] After completely dissolving 1.053 g of 95% thiamethoxam technical drug in 10 g of DMF, 2.5 g of component A from Example 1, 0.5 g of component B from Example 2, and 7 g of component C2 were added in sequence and mixed thoroughly. After that, 10 g of 15% matrine ointment and 68.947 g of water were added and mixed thoroughly. The precipitation and foaming of the preparation were examined.

[0056] Among them, the alkyl polyglycoside in component C2 is specifically 50% APG, the castor oil polyoxyethylene ether is specifically BY-125, the alkylphenol polyoxyethylene ether is specifically OP-8, and the fatty amide alkyl quaternary ammonium salt is specifically 30% fatty amide propyl dimethyl ammonium chloride; the content of each component, by weight:

[0057]

[0058] Comparative Example 1

[0059] Mix 7.8g of 95% NaOH and 40.66g of deionized water, then add 41.54g of 96.3% bentazon stock powder. Stir at 50°C-60°C, atmospheric pressure, and 450rpm until the reaction is complete. Stir for 1 hour. Add 10g of Component C1 from Example 3 and 0.05g of a water-soluble silicone defoamer and mix thoroughly. Impurities in bentazon stock easily form precipitates or floccules when formulated into a 40% bentazon aqueous solution, and these floccules are difficult to remove through physical methods such as sedimentation and filter presses. The effect of a common surfactant component C1 (using the composition ratio disclosed in Example 3) on the flocculent stability of the 40% bentazon aqueous solution was investigated.

[0060] Comparative Example 2

[0061] 1.053 g of 95% thiamethoxam technical drug was completely dissolved in 30 g of DMF, and 10 g of component C2 (the component ratio disclosed in Example 4) was added and mixed uniformly. 10 g of 15% matrine ointment and 48.947 g of water were also added and mixed uniformly. The precipitation and foaming of the preparation were examined when the common surfactant component C2 was used.

[0062] Comparative Example 3

[0063] 1.053 g of 95% thiamethoxam technical was completely dissolved in 78.947 g of DMF, and 10 g of component C2 (the component ratio disclosed in Example 4) was added and mixed uniformly. 10 g of 15% matrine ointment was also added and mixed uniformly. The precipitation and foaming of the preparation were investigated when the common surfactant component C2 was used.

[0064] result:

[0065] Table 1:

[0066]

[0067] Table 2:

[0068]

[0069]

[0070] Results: As shown in Table 1, the 40% bentazon aqueous solution, prepared using the common surfactants in Comparative Example 1, exhibited flocculent formation upon storage. The silicone defoamer, when used, easily floated and precipitated upon storage, resulting in a decline in defoaming performance. However, the block polyether emulsifier prepared in Example 1 resolved the flocculent and defoaming performance issues. As shown in Table 2, the formulations prepared using the common surfactants in Comparative Examples 2 and 3, using a 1.5% matrine + 1% thiamethoxam aqueous solution and 15% matrine ointment, required a large amount of the polar solvent DMF and resulted in precipitation upon storage. However, the block polyether emulsifier prepared in Example 2 reduced the amount of polar solvent DMF, resolved the precipitation issue, and produced low-foaming formulations.

[0071] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. Application of a block polyether emulsifier in pesticides, characterized by: Adding a block polyether emulsifier to the pesticide; the emulsifier comprises component A, component B, and component C, wherein component A is mainly synthesized from isomeric polyols, epoxides, a blocking agent 1, and a catalyst 1; component B is mainly synthesized from isomeric polyols, epoxides, a blocking agent 2, and a catalyst 1; component C is a surfactant; and the epoxide is a compound of ethylene oxide and propylene oxide; wherein the content of each component, by weight, is 10-30% component A, 5-10% component B, and 60-85% component C; The structural formula of the component A is: CH3CH[OCH2CH(CH3)] x (OCH2CH2) y OR2 | R1CH[OCH2CH(CH3)] x (OCH2CH2) y OR2; Wherein, R1 is H or CH3; R2 is one of COCH2NH2, COCH(NH2)CHOHCH3, COCH(NH2)CH2OH, COCH2CH(NH2)COOH, COCH2CH2CH(NH2)COOH; the molecular weight of component A is 2500-3500, 2≤x≤10, 15≤y≤40, x:y=(1:3)~(1:11), and the HLB value is 14~18; The structural formula of the component B is: CH3CH[OCH2CH(CH3)] m (OCH2CH2) n OR3 | R1CH[OCH2CH(CH3)] m (OCH2CH2) n OR3 Wherein, R1 is H or CH3, R3 is CH3, CH2(CH2)6CH3, CH2(CH2) 10 One of CH3; component B has a molecular weight of 1800-2500, 8≤m≤10, 1≤n≤2, m:n=9:1, and an HLB value of 1~3; The component C is one or more of alkyl glucosides, betaine, alkylphenol polyoxyethylene ether, castor oil polyoxyethylene ether, tallow amine polyoxyethylene ether, and cationic surfactants; The isomeric polyol is one of 1,2-propylene glycol and 2,3-butanediol; the catalyst I is one or more of an alkaline catalyst or a double metal cyanide complex; the capping agent 1 is any one of glycine, threonine, serine, glutamic acid, and aspartic acid; and the capping agent 2 is any one of monochloromethane, monochlorooctane, and lauryl chloride.

2. The use of a block polyether emulsifier in pesticides according to claim 1, characterized in that: The preparation method of the block polyether emulsifier comprises the following steps: (1) Catalyst I is placed in a kettle, and isomeric polyols are added for preheating. The temperature is gradually raised to 120-140°C, and the mixture is evacuated and nitrogen is introduced for 45-60 minutes. Propylene oxide is introduced at 135-145°C for ring-opening addition reaction. The pressure is controlled at 0-0.2 MPa, and the stirring speed is controlled at 450-600 rpm. After aging for 1-2 hours, the mixture is evacuated for 30 minutes, and ethylene oxide is introduced at 135-145°C for ring-opening addition reaction. The stirring speed is controlled at 350-450 rpm. The mixture is aged for 2-3 hours after the reaction to obtain a crude product, which is then washed and filtered to obtain an uncapped block polyether. (2) Take the end-capping reagent 1 and mix it with the hydrochloric acid aqueous solution, heat it to completely dissolve it, transfer the mixture to the reactor, mix it with the uncapped block polyether, stir it evenly, introduce nitrogen, control the reaction temperature to 90°C and react for 10 minutes. After the reaction is completed, the solution is clear and slightly yellow. Wash the solution with anhydrous ethanol and filter it to remove the end-capping reagent 1 that has not reacted in the system. Remove the ethanol solvent in the system by vacuum distillation, and then dry it at a constant temperature of 60°C to obtain component A; (3) Take the uncapped block polyether and react it with sodium methoxide, heat it to 120℃, react for 1~2h, then evacuate, cool it down after sufficient reaction, add the capping reagent 2, then gradually heat it up to and maintain the pressure in the autoclave to react, cool it down and discharge the material; add deionized water and phosphoric acid, stir and react for 1h, then wash and dehydrate to a water content of 0~0.5%, and filter to obtain component B; (4) Using surfactant as component C, component A, component B and component C are mixed to prepare a block polyether emulsifier.

3. The use of a block polyether emulsifier in pesticides according to claim 2, characterized in that: The catalyst I is one or more of an alkaline catalyst or a double metal cyanide complex, and the added amount is 0.02-1% of the total weight of the isomeric polyol.

4. The use of a block polyether emulsifier in pesticides according to claim 2, characterized in that: In step (2), the mass concentration of the hydrochloric acid aqueous solution is 2%; the mixing ratio of the end-capping agent 1 and the hydrochloric acid solution is 0.4 mol / 100 mL; and the molar ratio of the end-capping agent 1 to the uncapped block polyether is 2.1:1.

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