Imidacloprid wettable powder and its preparation method and application

Abstract

This invention provides a wettable powder of imidacloprid, the raw materials for which include: imidacloprid, a wetting and dispersing agent, a filler, and other additives, wherein the imidacloprid content is 15-25 wt%. The wetting and dispersing agent includes anionic, nonionic, and inorganic dispersants. The filler includes one or more of silica powder, quartz powder, clay, calcium oxalate, mica powder, carbon black, calcium sulfate, and alumina. This invention provides a wettable powder with excellent suspension and wettability.

Description

Technical Field

[0001] This invention relates to the field of pesticide technology, and in particular to imidacloprid wettable powder, its preparation method, and its application. Background Technology

[0002] Imidacloprid is a nitromethylene systemic insecticide, belonging to the chloronicotinamide class of insecticides, also known as neonicotinoid insecticides, with the chemical formula C9H. 10 C l N5O2. Imidacloprid was the first neonicotinoid insecticide to be marketed in 1991. Due to its high activity, strong rain resistance, and ease of seed treatment, it has gradually become one of the most widely used neonicotinoid insecticides. It has a broad spectrum, high efficiency, low toxicity, and low residue, and pests are unlikely to develop resistance. It also has multiple effects, including contact, stomach poison, and systemic action. It is used to control piercing-sucking pests such as aphids, leafhoppers, planthoppers, thrips, and whiteflies.

[0003] Wettable powder (WP) is a very fine dry agent obtained by mixing and pulverizing active ingredients, fillers, surfactants, and other adjuvants. Its main performance requirements include wettability, dispersibility, and suspension properties.

[0004] Currently, wettable powders suffer from low suspension rates, low wettability, easy sedimentation, and uneven spraying, which can affect efficacy or cause phytotoxicity. This invention provides an imidacloprid wettable powder formulation that, through formulation and process preparation, mitigates these performance instability issues associated with imidacloprid. Summary of the Invention

[0005] The purpose of this invention is to provide a wettable powder of imidacloprid, the raw materials for which include: imidacloprid, wetting and dispersing agent, filler, and other additives, wherein the imidacloprid content is 15-25 wt%.

[0006] In one embodiment of the present invention, the wetting and dispersing agent includes anionic wetting and dispersing agents, nonionic wetting and dispersing agents, and inorganic dispersing agents.

[0007] In one embodiment of the present invention, the anionic wetting and dispersing agent is an alkylbenzene sulfonate and / or an alkylnaphthalene sulfonate.

[0008] As one embodiment of the present invention, the nonionic wetting and dispersing agent includes fatty alcohol polyoxyethylene ether wetting and dispersing agents and / or EO / PO block copolymer wetting and dispersing agents.

[0009] In one embodiment of the present invention, the inorganic dispersant is a condensed phosphate wetting and dispersing agent.

[0010] In one embodiment of the present invention, the filler includes one or more of the following: silica powder, quartz powder, clay, calcium oxalate, mica powder, carbon black, calcium sulfate, and alumina.

[0011] In one embodiment of the present invention, the other additives include one or more of penetrants, spreading agents, stabilizers, defoamers, anti-caking agents, color-detecting agents, and synergists.

[0012] Preferably, a method for preparing the imidacloprid wettable powder comprises the following steps:

[0013] (1) Imidacloprid was pulverized into ultrafine particles;

[0014] (2) Stir and mechanically pulverize the remaining raw materials, and then perform ultrafine pulverization;

[0015] (3) The powders obtained from the ultrafine grinding in steps (1) and (2) are granulated, dried, and sieved.

[0016] In one embodiment of the present invention, the powder and solvent are mixed in step (3) and then granulated, and the mass ratio of the mixed powder to the solvent is (3-8):1.

[0017] Preferably, the imidacloprid wettable powder is used in the field of insecticide application.

[0018] By adopting the above technical solution, the present invention has the following beneficial effects:

[0019] This invention provides a wettable powder with excellent suspension rate and wettability. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] This invention provides an imidacloprid wettable powder, the raw materials for which include: imidacloprid, wetting and dispersing agent, filler, and other additives, wherein the imidacloprid content is 15-25 wt%.

[0022] Imidacloprid

[0023] In this invention, considering the physicochemical properties of the imidacloprid and the impurities that inevitably arise during the preparation process, the imidacloprid undergoes pretreatment during the preparation of the wettable powder.

[0024] In one embodiment of the present invention, the pretreatment involves mixing imidacloprid and a pretreatment agent, wherein the pretreatment agent is selected from proline or triethylamine.

[0025] The specific pretreatment method is to mix and dissolve imidacloprid and the pretreatment material in hot water according to the mass ratio, then cool to room temperature, and add ethanol to the alcohol content to 80%; then recrystallize at a cooling rate of 0.1-0.5℃ / min until crystals precipitate after refrigeration at 4℃ for 10 hours, filter, wash, and dry.

[0026] In one embodiment of the present invention, the mass ratio of imidacloprid to pretreatment material is 1:5-10; more preferably 1:6.

[0027] wetting and dispersing agents

[0028] The wetting and dispersing agents include anionic wetting and dispersing agents, nonionic wetting and dispersing agents, and inorganic dispersing agents.

[0029] The anionic wetting and dispersing agent is an alkylbenzene sulfonate and / or an alkylnaphthalene sulfonate.

[0030] The nonionic wetting and dispersing agents include fatty alcohol polyoxyethylene ether wetting and dispersing agents and / or EO / PO block copolymer wetting and dispersing agents.

[0031] The inorganic dispersant is a condensed phosphate wetting and dispersing agent.

[0032] In one embodiment of the present invention, the wetting and dispersing agent is Dispersol. TM BB4 and Dowfax D-800.

[0033] filler

[0034] The filler includes one or more of the following: silica powder, quartz powder, clay, calcium oxalate, mica powder, carbon black, calcium sulfate, and alumina.

[0035] In one embodiment of the present invention, the filler is a mixture of quartz powder, calcium oxalate and alumina, with a specific mass ratio of 0.1:0.1:1.

[0036] Other additives

[0037] The other additives include one or more of the following: penetrants, spreading agents, stabilizers, defoamers, anti-caking agents, color-detecting agents, and synergists.

[0038] In one embodiment of the present invention, the other additives are BYK-067A defoamer and fumed silica.

[0039] Another aspect of the present invention provides a method for preparing the imidacloprid wettable powder.

[0040] (1) Imidacloprid was pulverized into ultrafine particles;

[0041] (2) Stir and mechanically pulverize the remaining raw materials, and then perform ultrafine pulverization;

[0042] (3) The powders obtained from the ultrafine grinding in steps (1) and (2) are granulated, dried, and sieved.

[0043] In step (3), the mixed powder is mixed with the solvent and then granulated, and the mass ratio of the mixed powder to the solvent is (3-8):1.

[0044] Another aspect of the present invention provides the imidacloprid wettable powder for use in the field of insecticide application.

[0045] Example 1

[0046] This embodiment provides an imidacloprid wettable powder, which, by weight, comprises: 25% imidacloprid, 4% wetting and dispersing agent, 3% other additives, and filler to make up the remainder 100%.

[0047] In this embodiment, the imidacloprid undergoes pretreatment. Specifically, the pretreatment method is as follows: imidacloprid and proline are mixed and dissolved in hot water at a mass ratio of 1:6, then cooled to room temperature, and ethanol is added until the alcohol content reaches 80wt%. Subsequently, recrystallization is carried out at a cooling rate of 0.3℃ / min until crystals precipitate after refrigeration at 4℃ for 10 hours. The crystals are then filtered, washed, and dried.

[0048] The wetting and dispersing agent is Dispersol. TM BB4 and Dowfax D-800 were mixed at a mass ratio of 3:1.

[0049] The filler is a mixture of quartz powder, calcium oxalate and alumina, with a specific mass ratio of 0.1:0.1:1.

[0050] The other additives are BYK-067A defoamer and fumed silica mixed at a mass ratio of 2:1.

[0051] Another aspect of the present invention provides a method for preparing the imidacloprid wettable powder.

[0052] (1) Imidacloprid was pretreated and then ultra-finely pulverized;

[0053] (2) Stir and mechanically pulverize the remaining raw materials, and then perform ultrafine pulverization;

[0054] (3) The powders obtained from the ultrafine grinding in steps (1) and (2) are granulated, dried, and sieved.

[0055] In step (3), the mixed powder is mixed with water and then granulated, and the mass ratio of the mixed powder to water is 5:1.

[0056] Example 2

[0057] The difference from Example 1 is that imidacloprid was not pretreated.

[0058] Example 3

[0059] The difference from Example 1 is that the mass ratio of imidacloprid to proline is 1:4.

[0060] Example 4

[0061] The difference from Example 1 is that the mass ratio of imidacloprid to proline is 1:8.

[0062] Example 5

[0063] The difference from Example 1 is that the filler is alumina.

[0064] Example 6

[0065] The difference from Example 1 is that the filler is a mixture of quartz powder and alumina in a specific mass ratio of 0.1:1.

[0066] Example 7

[0067] The difference from Example 1 is that the filler is a mixture of quartz powder, calcium oxalate and alumina in a specific mass ratio of 1:1:1.

[0068] The imidacloprid technical grade was supplied by Yancheng Shuangning Agrochemical Co., Ltd.

[0069] Performance testing

[0070] Test 1: Fineness, suspension rate, wettability, and accelerated storage test were conducted in accordance with industry standard HG 3671-2000.

[0071] Table 1 Results of Test 1

[0072]

[0073]

[0074] Test 2: Field efficacy trial: Control of rice planthoppers with 25% imidacloprid wettable powder

[0075] Experimental crop: medium-grained rice, variety Zhendao 99.

[0076] Dosage: 120g per hectare (prepared dosage), application amount: 0.09g per 30 square meters (active ingredient amount).

[0077] Community area: 30 square meters per community, repeated 4 times.

[0078] Instructions for use: Use a manual sprayer to spray a coarse mist.

[0079] Equipment: Manual backpack sprayer 3WBS-16A.

[0080] Apply pesticide once at the late booting stage of rice, and apply pesticide during the peak period of young nymphs of the second generation of rice planthoppers.

[0081] The soil texture is mixed soil, with moderate fertility and a pH value of 6.9.

[0082] Methods for calculating drug efficacy

[0083] Insect population reduction rate = (Number of insects before application - Number of insects after application) / Number of insects before application * 100%

[0084] Prevention and control effect = (PT-CK) / (100-CK)*100%

[0085] Where: CK - insect population reduction rate in the blank control area, PT - insect population reduction rate in the pesticide-treated area

[0086] Based on the results of performance test 1, preliminary field efficacy tests were conducted on Examples 1, 2, 3, and 5, and the results are as follows:

[0087] Table 2 Overall Results of Test 2

[0088]

[0089] Table 3. Specific test data results for Test 2 (1)

[0090]

[0091]

[0092] Table 4. Specific test data results for Test 2 (2)

[0093]

[0094] Table 5. Statistical Table of Test 2 Results (1)

[0095]

[0096]

[0097] Table 6. Statistical Table of Test 2 Results (2)

[0098]

[0099] In summary, the wettable powder prepared using this invention can achieve good suspension rate, fineness, storage properties, and field efficacy; however, it was also found that using pretreated imidacloprid requires matching with specific fillers to achieve better results.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wettable powder of imidacloprid, characterized in that, According to the mass fraction, the raw materials for its preparation include: 25% imidacloprid, 4% wetting and dispersing agent, 3% other additives, and filler to make up the balance of 100%; The imidacloprid underwent pretreatment, specifically as follows: imidacloprid and proline were mixed and dissolved in hot water at a mass ratio of 1:6, then cooled to room temperature, and ethanol was added until the alcohol content reached 80 wt%. Subsequently, recrystallization was carried out at a cooling rate of 0.3 °C / min until crystals precipitated after refrigeration at 4 °C for 10 hours. The crystals were then filtered, washed, and dried. The wetting and dispersing agent is a mixture of Croda Dispersol™ BB4 and Dowfax D-800 in a mass ratio of 3:1; The filler is a mixture of quartz powder, calcium oxalate and alumina, with a specific mass ratio of 0.1:0.1:1; The other additives are BYK-067A defoamer and fumed silica mixed at a mass ratio of 2:

1.

2. The method for preparing imidacloprid wettable powder according to claim 1, characterized in that, The steps are as follows: (1) Imidacloprid was pretreated and then ultra-finely pulverized; (2) Stir and mechanically pulverize the remaining raw materials, and then perform ultrafine pulverization; (3) The powder obtained by mixing the ultrafine grinding in steps (1) and (2) is granulated, dried, and sieved. In step (3), the mixed powder is mixed with water and then granulated, and the mass ratio of the mixed powder to water is 5:

1.

3. The imidacloprid wettable powder of claim 1 is used in the field of insecticide application.

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