Aqueous suspension containing acetamiprid and high-efficiency cyhalothrin and preparation method thereof

Abstract

The invention discloses a kind of water suspension containing acetamiprid and high-efficiency chlorflucythrin and its preparation method, and is composed of the following components in percentage by mass: active ingredient 1-60%, dispersant 6-10%, wetting dispersant 1-3%, thickener 1-3%, antifreeze 4-6%, defoamer 0.2-0.5%, pH regulator 0.1-0.5%, preservative 0.1-0.3%, water surplus. The water suspension preparation of the present invention has good emulsification dispersibility, low viscosity, high suspension rate, and can tolerate 0 DEG C to 54 DEG C high and low temperature intervals, is not easily affected by environmental changes during sea transportation, is not easy to appear caking, creaming, particle size growth, crystallization, even decomposition and the like after temperature rises, and is not easy to appear crystallization risk when temperature is reduced, thereby ensuring the insecticidal effect.

Description

Technical Field

[0001] The invention relates to a pesticide water suspension concentrate, in particular to a water suspension concentrate containing acetamiprid and lambda-cyhalothrin and a preparation method thereof, belonging to the technical field of pesticide preparations. Background Art

[0002] Acetamiprid (chemical name: N-(N-cyano-ethylimino)-N-methyl-2-chloropyridine-5-methylamine) is a nitromethylene heterocyclic compound. It is a new broad-spectrum insecticide with certain acaricidal activity. It is particularly effective against pests resistant to organophosphorus, carbamates and pyrethroids. The original drug is white crystals with a melting point of 101.0-103.3℃ and a vapor pressure of >1.33×10-6 Pa (25℃). The solubility in water at 25℃ is 4200 mg /

[0003] Liter, soluble in acetone, methanol, ethanol, dichloromethane, chloroform, acetonitrile, tetrahydrofuran, etc. It is stable in water at pH=7, gradually hydrolyzes at 45°C at pH=9, and is stable under sunlight. The main formulation products are emulsifiable concentrate, water emulsion, wettable powder and water-dispersible granules.

[0004] Lambda-cyhalothrin (chemical name: 3-(2-chloro-3,3,3-trifluoropropenyl)-2,2-dimethylcyclopropanecarboxylic acid α-cyano-3-phenoxybenzyl ester) is a pyrethroid insecticide and acaricide, which mainly acts as a contact and stomach poison, and has no systemic effect. It has good effects on various pests of Lepidoptera, Coleoptera and Hemiptera, as well as spider mites, rust mites, gall mites, tarsonemes, etc. It can also be used to control a variety of surface and public health pests. It has a certain preventive effect on pests with piercing-sucking mouthparts, but long-term use is easy to produce resistance to it. The pure product is a white solid, and the industrial product is a light yellow solid. The melting point is 49.2℃, and the vapor pressure is 200×10-9Pa (2.67×10-7Pa) (20℃). The boiling point is 187-190℃. It is easily soluble in acetone, methanol, ethyl acetate, toluene and other organic solvents, with solubility greater than 500g / L. It is insoluble in water. It can be stably stored for more than half a year at room temperature. The half-life in water under sunlight is 20 days; the half-life in soil is 22-82 days. The main formulation products are emulsifiable concentrates, water emulsions, and microcapsule suspensions.

[0005] Long-term and large-scale use of a single insecticide can easily cause pests to develop resistance, resulting in increased dosage, reduced efficacy, and shortened duration, which is not conducive to environmental sustainable development. One of the commonly used methods to delay the development of resistance in pests is to compound active ingredients with different mechanisms of action. The mechanism of action of acetamiprid and highly effective chlorflucythrinate is different. Research on the compound preparation of acetamiprid and highly effective chlorflucythrinate will have good application prospects. Patents such as CN104430485A and CN 104351239 A have demonstrated the synergistic effect of compound preparations containing acetamiprid and highly effective chlorflucythrinate.

[0006] Water suspension preparation is one of the environmentally friendly formulations recognized by the pesticide industry. The emergence of this formulation has created broad development prospects for the production and application of many pesticides that are neither hydrophilic nor lipophilic. Suspension concentrate is a new formulation developed in the 1970s. It is relatively short in the history of pesticide formulation development. In recent decades, it has developed rapidly at home and abroad and is constantly improving. It has partially replaced wettable powders and emulsifiable concentrates, and has gradually become an excellent formulation to replace powder formulations. However, there are two restrictions on the processing of water suspension pesticides. One is that the water solubility of the active ingredient of the pesticide must be less than or equal to 100 mg / L, preferably insoluble, and the other is that the melting point of the active ingredient of the pesticide must be greater than 60°C. If the water solubility is greater than 100 mg / L, it is easy to produce Ostwald ripening during the storage of the preparation, that is, the crystal growth phenomenon; if the melting point is less than 60°C, it is easy to deform during the sand grinding process, and the temperature changes greatly during the storage of the preparation, which is likely to cause the original drug to melt, causing particle agglomeration, and even crystallization. For pesticides with a solubility in water slightly greater than 100 mg / L or a melting point less than 60°C, it is possible to prepare them into aqueous suspensions through the adjustment of additives, but the processing is more difficult and the stability of the preparation is difficult to ensure.

[0007] The solubility of acetamiprid in water is 4200 mg / L, which is far greater than the restriction of 100 mg / L. The melting point of highly effective chlorfenapyr is 49.2°C, which is far lower than the restriction of 60°C. Moreover, the two restrictions exist at the same time. Therefore, it is very difficult to compound acetamiprid and highly effective chlorfenapyr into a stable aqueous suspension. This is also the reason why there are no such products on the market.

[0008] CN106719621A discloses a surfactant composition for acetamiprid aqueous suspension and a preparation method thereof, which mainly describes that a qualified 20% acetamiprid aqueous suspension can be produced using the surfactant composition provided by this scheme. The surfactant combination is mainly a composition of a block copolymer of ethylene oxide and propylene oxide, xanthan gum, magnesium aluminum silicate, ethylene glycol and water. The particle size growth rate of the acetamiprid suspended particles in the obtained acetamiprid aqueous suspension is relatively large, which is not conducive to long-term storage.

[0009] CN111887257A discloses a stable acetamiprid water suspension preparation and a method for improving the stability of the acetamiprid water suspension preparation. It mainly describes that by adding vegetable oil to the water suspension preparation containing the acetamiprid active ingredient, the risk of particle size growth of the acetamiprid suspension particles during storage is suppressed, thereby effectively improving the storage stability of the water suspension preparation containing acetamiprid.

[0010] CN101828571B discloses a pesticide water suspension containing high-efficiency cyhalothrin and a preparation method thereof, which is composed of 10.0% high-efficiency cyhalothrin original drug, 6.0% nonylphenol polyoxyethylene ether, 0.45% thickener WJZ-04, 3% defoamer 8431, 6.0% antifreeze agent ethylene glycol, and water supplemented to 100%. The high-efficiency cyhalothrin water suspension obtained has poor dispersion and high viscosity, and in particular, cannot ensure the particle dispersibility after hot storage is transferred to room temperature, which is not conducive to long-term storage.

[0011] In summary, the preparation of a stable aqueous suspension formulation of acetamiprid and cyhalothrin is still a problem for formulation engineers due to the high solubility of acetamiprid and the low melting point of cyhalothrin. Therefore, it is still of great significance to develop an aqueous suspension formulation that can maintain stability during storage. Summary of the invention

[0012] In view of the high water solubility of acetamiprid and the low melting point of cyhalothrin, it is difficult to ensure the excellent stability of water suspension over time. Therefore, the compound preparations of acetamiprid and cyhalothrin currently on the market are emulsifiable concentrates and water-dispersible granules, and it is very difficult to develop them into water suspensions. Water suspensions have the advantages of using water as a dispersion medium, low cost, good environmental compatibility, basically no three wastes pollution in the production process, safe storage and transportation, small particle size of the dispersed original drug, high suspension rate, and easy use. Therefore, developing the two into water suspensions has good economic benefits.

[0013] In order to solve the problem of preparing water suspension concentrates with acetamiprid and high-efficiency chlorflucythrinate, the inventors have conducted a large amount of screening work on the formulation system, and finally obtained the auxiliary agent system with the best matching degree, thereby obtaining a water suspension preparation with excellent performance. The water suspension concentrate containing acetamiprid and high-efficiency chlorflucythrinate of the present invention includes active ingredients and auxiliary agents, and the auxiliary agents are dispersants, wetting dispersants, thickeners, defoamers, antifreeze agents, pH regulators, preservatives and water. The active ingredient is composed of acetamiprid and high-efficiency chlorflucythrinate. In the active ingredient, the mass ratio of acetamiprid to high-efficiency chlorflucythrinate is (1-20):1.

[0014] The present invention greatly reduces the processing difficulty of the dosage form and greatly improves the stability of the dosage form through the coordinated coordination of various auxiliary agents, especially the screening and combination of dispersants and wetting dispersants. The obtained product has strong time stability, low viscosity, and can withstand high and low temperature ranges of 0°C to 54°C, effectively reducing or solving the influence of environmental changes on the stability of the dosage form during transportation, reducing or avoiding product quality problems such as dosage form agglomeration, creaming, particle size growth, crystallization, decomposition, etc., improving the stability of the preparation and improving the insecticidal effect.

[0015] Furthermore, the dispersant is at least one of lignin sulfonate, naphthalene sulfonate formaldehyde condensate, formaldehyde cresol sulfonate sodium salt, styrene acrylic acid copolymer sodium salt, styrene acrylic acid maleic anhydride copolymer sodium salt and styrene maleic anhydride copolymer sodium salt, preferably a mixture of styrene acrylic acid maleic anhydride copolymer sodium salt, naphthalene sulfonate formaldehyde condensate and formaldehyde cresol sulfonate sodium salt.

[0016] Furthermore, when the dispersant is a mixture of styrene acrylic acid maleic anhydride copolymer sodium salt, naphthalene sulfonate formaldehyde condensate, and formaldehyde cresol sulfonate sodium salt, the mass ratio of styrene acrylic acid maleic anhydride copolymer sodium salt, naphthalene sulfonate formaldehyde condensate, and formaldehyde cresol sulfonate sodium salt is 1-3:1:1.

[0017] Furthermore, the wetting and dispersing agent is at least one of phenethylphenol polyoxyethylene polyoxypropylene ether, propylene oxide-ethylene oxide block polyether, fatty alcohol polyoxyethylene ether phosphate and castor oil polyoxyethylene ether phosphate, preferably propylene oxide-ethylene oxide block polyether.

[0018] Furthermore, the thickener is at least one of ordinary white carbon black, magnesium aluminum silicate, methyl cellulose, organic bentonite and xanthan gum, preferably a mixture of ordinary white carbon black, magnesium aluminum silicate and xanthan gum.

[0019] Furthermore, the antifreeze agent is at least one of urea, ethylene glycol, propylene glycol, glycerol, polyethylene glycol and sodium chloride, preferably ethylene glycol.

[0020] Furthermore, the defoamer is at least one of a polyether defoamer and a silicone defoamer, preferably a silicone defoamer.

[0021] Furthermore, the pH adjuster is at least one of citric acid and acetic acid, preferably citric acid.

[0022] Furthermore, the preservative is at least one of kason, paraformaldehyde and sodium benzoate, preferably kason.

[0023] Furthermore, in the above-mentioned aqueous suspension, the content of the active ingredient is 1-60wt%, for example, 1wt%, 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt%.

[0024] Furthermore, in the above-mentioned aqueous suspension, the content of the dispersant is 6-10wt%, for example, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%.

[0025] Furthermore, in the above-mentioned aqueous suspension, the content of the wetting and dispersing agent is 1-3wt%.

[0026] Furthermore, in the above aqueous suspension, the content of the thickener is 1-3wt%.

[0027] Furthermore, in the above-mentioned water suspension, the content of antifreeze is 4-6wt%.

[0028] Furthermore, in the above aqueous suspension, the content of the defoaming agent is 0.2-0.5wt%.

[0029] Furthermore, in the above aqueous suspension, the content of the pH regulator is 0.1-0.5 wt%.

[0030] Furthermore, in the above-mentioned aqueous suspension, the content of the preservative is 0.1-0.3wt%.

[0031] Furthermore, in the above-mentioned aqueous suspension, the amount of water used is to make up the surplus to ensure that the content of the above-mentioned components is within the specified range.

[0032] The present invention also provides a method for preparing the above-mentioned aqueous suspension containing acetamiprid and high-efficiency chlorflucythrinate, which comprises the following steps: mixing water, a dispersant, a wetting dispersant and a preservative, adding a thickener, a defoamer, an antifreeze agent, a pH regulator, acetamiprid and high-efficiency chlorflucythrinate under high-speed shearing conditions, shearing for 10 to 30 minutes, and then grinding until the particle size D90 of the mixture is less than 5 μm, to obtain an aqueous suspension containing acetamiprid and high-efficiency chlorflucythrinate.

[0033] Furthermore, the speed of high-speed shearing is generally 8000-10000 r / min.

[0034] The advantages of the present invention are as follows:

[0035] 1. The present invention screens the auxiliary agent system, and obtains a stable composite water suspension preparation of acetamiprid and highly effective chlorfenapyr by matching various auxiliary agents, especially dispersants and wetting dispersants, which greatly reduces the processing difficulty of the dosage form. While ensuring the time stability of the product, it effectively reduces or solves the impact of environmental changes during transportation, reduces or avoids the occurrence of product quality problems such as agglomeration, creaming, particle size growth, crystallization, and decomposition of the water suspension, improves the stability of the preparation, and improves the insecticidal effect of acetamiprid.

[0036] 2. The water suspension preparation of the present invention has good emulsification and dispersibility, low viscosity, high suspension rate, and can withstand high and low temperature ranges of 0°C to 54°C. It is not easily affected by environmental changes during sea transportation. When the temperature rises, it is not easy to cause caking, creaming, particle size growth, crystallization, or even decomposition. When the temperature drops, it is not easy to cause the risk of crystallization, thereby ensuring the insecticidal effect.

[0037] 3. The water suspension concentrate provided by the present invention provides a good idea for solving the stability problem of the water suspension concentrate of high-solubility and low-melting-point pesticide compound. The present invention will play a certain role in promoting the development of pesticide formulations in my country and will also bring good economic benefits to enterprises.

[0038] 4. The aqueous suspension concentrate of the present invention can realize the compounding of acetamiprid and high-efficiency chlorflucythrinate, thereby improving the insecticide effect, reducing the dosage of the agent, and reducing the agent cost. DETAILED DESCRIPTION

[0039] The technical content of the present invention is further explained below through specific embodiments, but the essential content of the present invention is not limited to the following embodiments.

[0040] Unless otherwise specified, the following percentages are all by weight.

[0041] Example 1

[0042] A water suspension, the formula is shown in Table 1, the content of each component is (wt%): active ingredient 10%, dispersant styrene acrylic acid maleic anhydride copolymer sodium salt 2%, naphthalene sulfonate formaldehyde condensate 2%, formaldehyde cresol sulfonic acid sodium salt 2%, wetting dispersant propylene oxide-ethylene oxide block polyether 2%, thickener ordinary white carbon black 1%, magnesium aluminum silicate 1%, xanthan gum 0.25%, antifreeze agent ethylene glycol 5%, defoamer organosilicon defoamer 0.2%, pH adjuster citric acid 0.15%, preservative kason 0.1%, water balance. Among them, the active ingredients are acetamiprid and high-efficiency chloranthrin in a mass ratio of 1:1.

[0043] The preparation method of the above-mentioned aqueous suspension concentrate is: water, dispersant, wetting dispersant and preservative are mixed, and thickener, defoamer, antifreeze agent, pH adjuster, acetamiprid and high-efficiency chlorflucythrinate are added under high-speed shearing state, the shearing speed is 8000-10000r / min, the shearing time is 10-30 minutes, and then grinding is carried out until the particle size D90 of the mixture is less than 5μm to obtain an aqueous suspension concentrate containing acetamiprid and high-efficiency chlorflucythrinate.

[0044] Examples 2-12 and Comparative Example 1

[0045] A series of aqueous suspensions were prepared according to the formulations in Table 1. The preparation methods of the aqueous suspensions were similar to those in Example 1.

[0046] Table 1

[0047]

[0048]

[0049]

[0050] The performance of the water suspension concentrates prepared in the above examples and comparative examples was tested, and the results are shown in the following Table 2. The suspension rate was tested according to the GB / T14825-2006 pesticide suspension rate determination method, and the viscosity was tested using a rotational viscometer.

[0051] Table 2 Performance of water suspension prepared by compounding acetamiprid and high-efficiency chlorflucythrinate

[0052]

[0053]

[0054] As shown in Table 2, the quality of the comparative example is not good, and after the cold and hot storage is transferred to room temperature, the sample has no fluidity. The quality of Examples 1-12 is good before and after cold and hot storage, among which Examples 1-6 made with the preferred auxiliary agent have the best quality, and the suspension rate is >95%; the quality of Examples 7-12 is slightly reduced, but the suspension rate is >85%, which meets the actual medication requirements. It can be seen that the preferred auxiliary agent plays a key role in product quality.

Claims

1. An aqueous suspension containing acetamiprid and high-efficiency cyhalothrin, characterized in that The invention is composed of the following components in percentage by mass: 1-60% active ingredient, 6-10% dispersant, 1-3% wetting and dispersing agent, 1-3% thickener, 4-6% antifreeze agent, 0.2-0.5% defoamer, 0.1-0.5% pH regulator, 0.1-0.3% preservative, and the balance is water; the active ingredients are acetamiprid and high-efficiency chlorflucythrin; the dispersant is a mixture of sodium salt of styrene acrylic acid maleic anhydride copolymer, naphthalene sulfonate formaldehyde condensate, and sodium salt of formaldehyde cresol sulfonate in a mass ratio of 1-3:1:1; the wetting and dispersing agent is propylene oxide-ethylene oxide block polyether; the thickener is at least one of ordinary white carbon black, magnesium aluminum silicate and xanthan gum; the antifreeze agent is ethylene glycol; the defoamer is an organosilicon defoamer; the pH regulator is citric acid; and the preservative is kasone.

2. A method for preparing the aqueous suspension containing acetamiprid and efficient chlorfenapyr according to claim 1, characterized in that The following steps are involved: Water, dispersant, wetting dispersant and preservative are mixed, and thickener, defoamer, antifreeze agent, pH adjuster, acetamiprid and high-efficiency chlorflucythrin are added under high-speed shearing state, and shearing is carried out for 10 to 30 minutes, and then ground until the particle size D90 of the mixture is less than 5µm, so as to obtain an aqueous suspension containing acetamiprid and high-efficiency chlorflucythrin.

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