Aquacide dichloride soluble concentrate as well as preparation method and application thereof

Abstract

According to the aquacide dichloride soluble concentrate provided by the invention, by reasonably selecting the variety and content of auxiliaries, the stability of a product is improved, the cold storage stability and the heat storage stability are good, the uniform state can be kept in different temperature environments, the problems of layering, crystallization / precipitation and the like are not prone to occurring, and the aquacide dichloride soluble concentrate can adapt to high-hardness water dilution. The preparation method of the aquacide dichloride soluble concentrate is simple and easy to operate, the production cost is low, and through strict quality control indexes, the impurity content in the product is effectively reduced, and the pollution to the environment is reduced. The aquacide dichloride soluble concentrate disclosed by the invention is mainly used for preventing and controlling weeds in uncultivated areas, can be quickly absorbed by green tissues of the weeds, is high in weeding speed and good in effect, has small influence on non-target organisms under a specified dosage, and meets the requirements of environmental protection and safety.

Description

Technical Field

[0001] This invention relates to the field of pesticide formulations, specifically to the design of dichlorvos dichloride soluble concentrate, its preparation method, and its application. Background Technology

[0002] Diquat dichloride, chemically known as 1,1'-ethylidene-2,2'-bipyridine dichloride, with the molecular formula C12H12Cl2N2, is a white to yellow crystalline powder. It is readily soluble in water (approximately 700 g / L at 20°C), slightly soluble in ethanol, and insoluble in nonpolar organic solvents. It is stable in acidic and neutral solutions but readily decomposes under alkaline conditions, especially above 300°C. It is a pyridine cationic non-selective contact herbicide with stable physicochemical properties. It is rapidly absorbed by plant green tissues, inhibiting the electron transport chain in photosynthesis, causing the reduced bipyridine compound to oxidize into hydrogen peroxide, damaging cell membranes, leading to leaf yellowing and death. It loses its activity upon contact with soil. Diquat dichloride is effective against broadleaf weeds (such as fleabane and purslane) and some grassy weeds (such as goosegrass and crabgrass), and is particularly effective against glyphosate-resistant weeds. It can be used for weeding in non-arable land and orchards, and for pre-harvest drying of crops such as rice, cotton, and potatoes, accelerating the drying of residual green tissue, reducing seed loss, and promoting the decomposition of previous crop residues, thus improving land utilization. Common formulations of diquat dichloride include soluble and aqueous solutions.

[0003] Chinese patent application CN108353915A discloses a soluble concentrate containing dichlorvos dichloride, which uses alkaline ammonia water as a pH adjuster. However, dichlorvos dichloride aqueous solution is weakly acidic and will accelerate hydrolysis and inactivation upon contact with alkaline substances. This application also does not provide corresponding quality control data, and it cannot be determined whether a stable dichlorvos dichloride soluble concentrate can be obtained. Summary of the Invention

[0004] This invention provides a dichlorvos dichloride soluble concentrate, characterized in that, by mass percentage, it contains 8.0-12.0% dichlorvos dichloride, 3.0-7.0% cationic surfactant, 0-10% anionic / nonionic surfactant, 0-6% stabilizer, 0.5-1.5% pH adjuster, and the balance being deionized water.

[0005] Preferably, the cationic surfactant can be one or more of the following: polyether-modified trisiloxane quaternary ammonium salt, lauramide propyl dimethyl tertiary amine, hexadecyltrimethylammonium chloride, dodecyldimethylbenzylammonium chloride, dioctadecyldimethylammonium chloride, and hexadecylpyridine ammonium chloride.

[0006] Preferably, the anionic surfactant can be one or more of sodium dodecylbenzenesulfonate, calcium dodecylbenzenesulfonate, sodium dibutylnaphthalenesulfonate, sodium ligninsulfonate, sophorolipid, alkylphenol polyoxyethylene ether phosphate, and sodium fatty alcohol polyoxyethylene ether sulfate.

[0007] Preferably, the nonionic surfactant can be one or more of fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, sorbitan fatty acid ester and its polyoxyethylene derivatives, block polyether, and alkyl glycoside.

[0008] Preferably, the stabilizer can be one or more of ammonium sulfate, ammonium nitrate, and disodium EDTA.

[0009] Preferably, the pH adjuster can be one or more of citric acid, hydrochloric acid, ammonium dihydrogen phosphate, glacial acetic acid, and oxalic acid.

[0010] This invention provides a method for preparing a dichlorvos dichloride soluble concentrate, comprising the following steps: (1) Add deionized water and dichlorvos dichlorvos to the preparation vessel, turn on the stirrer, and stir for 20-40 minutes to dissolve and mix; (2) Add cationic / anionic / nonionic surfactants and stabilizers to the preparation vessel, continue stirring for 30-60 minutes until well mixed, then add pH adjuster, stir for 20-40 minutes until well mixed; (3) After passing the test, filter, settle for 10-16 hours, and repackage; if the test fails, make adjustments until the test passes, and then filter, settle, and repackage.

[0011] Preferably, if the temperature is low in winter and affects the fluidity of the additives, the heating device of the stirring vessel can be turned on in step (2) and heated to above 50°C. Then, surfactants, stabilizers, etc. can be added slowly to improve the fluidity of the preparation, reduce the viscosity, and make it mix better.

[0012] The dichlorvos dichloride soluble concentrate of the present invention is mainly used for the control of weeds in non-cultivated land. It is applied once during the peak growth period of weeds, with a dosage of 500-700 ml / mu, diluted with 40-60 kg of water, and sprayed evenly on the stems and leaves of weeds.

[0013] By adopting the above technical solution, the present invention has the following beneficial effects: (1) The dichlorvos dichloride soluble agent of the present invention improves the stability of the product by rationally selecting the type and content of the adjuvants. It has good stability in cold and hot storage and can maintain a uniform state under different temperature environments. It is not easy to have problems such as layering, crystallization / precipitation. It can be adapted to dilution with high hardness water.

[0014] (2) The preparation method of the dichlorvos dichloride soluble agent of the present invention is simple and easy to operate, with low production cost, and through strict quality control indicators, it effectively reduces the impurity content in the product and reduces environmental pollution.

[0015] (3) The dichlorvos dichloride soluble agent of the present invention is mainly used for the control of weeds in non-cultivated land. It can be quickly absorbed by the green tissues of weeds, and has a fast weeding speed and good effect. Moreover, under the prescribed dosage, it has little impact on non-target organisms, which meets the requirements of environmental protection and safety. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a production process flow diagram for formulation example 3. Detailed Implementation

[0018] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and 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.

[0019] I. Formulation Examples Example 1: Formula composition

[0020] Preparation method: (1) Add deionized water and dichlorvos dichlorvos to the preparation vessel, turn on the stirrer, stir for 30 minutes to dissolve and mix; (2) Add lauramide propyl dimethyl tertiary amine and hexadecyltrimethylammonium chloride to the preparation vessel, continue stirring for 40 minutes until well mixed, then add citric acid and stir for 30 minutes until well mixed; (3) After passing the test, filter, settle for 12 hours, and repackage; if the test fails, make adjustments until the test passes, and then filter, settle, and repackage.

[0021] Example 2: Formula composition

[0022] Preparation method: (1) Add deionized water and dichlorvos dichlorvos to the preparation vessel, turn on the stirrer, stir for 30 minutes to dissolve and mix; (2) Add sodium lauryl polyoxyethylene ether sulfate, hexadecyltrimethylammonium chloride, disodium EDTA and alkyl glycoside to the preparation vessel, continue stirring for 40 minutes to mix evenly, then add citric acid and stir for 30 minutes to mix evenly; (3) After passing the test, filter, settle for 12 hours, and repackage; if the test fails, make adjustments until the test passes, and then filter, settle, and repackage.

[0023] Example 3: Formula composition

[0024] Preparation method: (1) Add deionized water and dichlorvos dichlorvos to the preparation vessel, turn on the stirrer, stir for 30 minutes to dissolve and mix; (2) Add hexadecyltrimethylammonium chloride, alkyl glycoside, sophorolipid and ammonium sulfate to the preparation vessel, continue stirring for 40 minutes to mix evenly, then add citric acid and stir for 30 minutes to mix evenly; (3) After passing the test, filter, settle for 12 hours, and repackage; if the test fails, make adjustments until the test passes, and then filter, settle, and repackage.

[0025] II. Formulation Performance Testing 1. Quality control index testing The relevant quality control indicators of the diquat dichloride soluble powder of this invention were tested in accordance with standards such as "HG / T 2467.7-2003 Specification for Writing Product Standards of Pesticide Soluble Powders".

[0026] Multiple batches of samples from Examples 1-3 were prepared and tested, and all indicators met the standards listed in the table below.

[0027] Table 1: Quality Control Indicator Data

[0028] 2. Stability test after dilution with three times hard water Table 1 shows the dilution stability of samples tested using standard hard water. The dilution stability of samples from Examples 1-3 of this application all met the requirements. However, in some regions where water hardness is high, the formulation still needs to maintain stability when diluted with water of high hardness.

[0029] Referring to the "HG / T 2467.7-2003 Specification for Writing Product Standards for Soluble Pesticides", the stability of the samples in Examples 1-3 after dilution with three times the amount of hard water was tested.

[0030] Table 2: Stability data after dilution with three times hard water

[0031] Unbound by any theoretical constraints, the inventors believe that the pH adjuster citric acid in Examples 1-3 has a certain complexing effect, and can complex calcium and magnesium ions without producing precipitates when diluted with standard hard water. However, under three times the hard water conditions, the complexing effect of citric acid is insufficient, so the sample of Example 1 produced a small amount of precipitation and had poor redispersibility; in Examples 2 and 3, the stabilizer disodium EDTA or ammonium sulfate was added in addition, which, in combination with citric acid, could fully complex calcium and magnesium ions in three times the hard water, producing only a small amount of precipitation or no precipitation at all, and the precipitation basically disappeared after 30 inversions.

[0032] III. Efficacy Tests Test location: The main weeds on a section of the Beijing-Guangzhou railway embankment include foxtail grass ( Green setaria ), humulus ( Hops climbing ), ragweed ( Ragweed fescue () Sheep fescue )wait Experimental Design: Samples from Examples 1, 2, and 3 were used in 3 replicates in a randomized block design. Water spray was used as a blank control. The dosage was 600 mL / mu, diluted with 50 kg of water, and sprayed directionally using a backpack electric sprayer (nozzle 30 cm above the ground to prevent drift). Each sampling point was 0.25 m² (0.5 m × 0.5 m), with 15 sampling points per treatment group (3 replicates × 5 points). Basic weed status data were collected one day before application, and the control efficacy was assessed 14 days after application. The control efficacy was calculated using the following formula: Strain control effect=(1 (Number of plants after treatment in the treatment area × Number of plants before treatment in the control area / Number of plants before treatment in the treatment area × Number of plants after treatment in the control area) × 100% The significance of the differences was analyzed using Duncan's new multiple range method (P < 0.05). Table 3: Weed Control Efficacy Data

[0033] The data is in the form of "mean ± standard deviation"; Letter labels (A / B) indicate a significant difference at the P < 0.05 level; The coefficient of variation between experimental replicates is ≤12%, which meets the requirements of GB / T 17980.41-2000. The experimental data above show that the products in Examples 1-3 can produce high weed control efficacy, all exceeding 80%. Example 1 uses a combination of two cationic surfactants, laurylamidopropyl dimethyl tertiary amine and hexadecyltrimethylammonium chloride. Example 3 uses a combination of the cationic surfactant hexadecyltrimethylammonium chloride, the nonionic surfactant alkyl glycoside, and the anionic surfactant sophorolipid. This combination significantly improves the wettability and penetration of the formulation on the weed surface, resulting in a significantly higher weed control effect than the product in Example 2. In particular, Example 3 also uses the stabilizer ammonium sulfate, which, in addition to its complexing and stabilizing effect, enhances the permeability of plant cell membranes, further improving pesticide penetration and achieving a total weed control efficacy of nearly 95%.

[0034] 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 dichlorvos dichloride soluble concentrate, characterized in that, By mass percentage, it contains 8.0-12.0% dichlorvos dichlorvos, 3.0-7.0% cationic surfactant, 0-10% anionic / nonionic surfactant, 0-6% stabilizer, 0.5-1.5% pH adjuster, and the balance is deionized water; The cationic surfactant is one or more of lauramide propyl dimethyl tertiary amine and hexadecyltrimethylammonium chloride; the anionic surfactant is one or more of sophorolipid and sodium fatty alcohol polyoxyethylene ether sulfate; the nonionic surfactant is an alkyl glycoside; the stabilizer is one of ammonium sulfate or disodium EDTA; and the pH adjuster is citric acid.

2. The method for preparing the dichlorvos dichloride soluble concentrate according to claim 1, characterized in that, Includes the following steps: (1) Add deionized water and dichlorvos dichlorvos to the preparation vessel, turn on the stirrer, and stir for 20-40 minutes to dissolve and mix; (2) Add cationic / anionic / nonionic surfactants and stabilizers to the preparation vessel, continue stirring for 30-60 minutes until well mixed, then add pH adjuster, stir for 20-40 minutes until well mixed; (3) After passing the test, filter, settle for 10-16 hours, and repackage; if the test fails, make adjustments until the test passes, and then filter, settle, and repackage.

3. The method for preparing the dichlorvos dichloride soluble concentrate according to claim 2, characterized in that, In step (2), the heating device of the stirring vessel can be turned on and heated to above 50°C, and then the surfactant and stabilizer can be slowly added.

4. The use of the dichlorvos dichloride soluble concentrate according to claim 1 in the control of weeds on non-cultivated land.

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