A picoxystrobin·tebuconazole suspension and preparation method thereof

Abstract

The invention provides a picoxystrobin·tebuconazole suspension, comprising the following weight percentage components: 5-15% of picoxystrobin, 15-25% of tebuconazole, 0.5-3% of hydroxypolyethylene oxide-nonionic block copolymer, 2-6% of polyaryl phenyl ether phosphate derivative, 1-3% of ethoxy / propoxy alcohol, 3-7% of ethylene glycol, 0.1-0.3% of bactericide BIT20, 0.01-0.1% of ethoxy-modified trisiloxane, 0.5-2% of alkoxylated ethylenediamine, 0.5-2% of magnesium aluminum silicate, 0.1-0.5% of xanthan gum, and deionized water supplemented to 100%. The preparation has excellent heat storage stability and excellent rainwater erosion resistance; and the prepared picoxystrobin·tebuconazole suspension has excellent control effect on rice false smut.

Description

Technical Field

[0001] The invention relates to the technical field of pesticides, in particular to a picoxystrobin-tebuconazole suspension and a preparation method thereof. Background Art

[0002] For a long time, the irrational use of chemical pesticides has brought about a series of difficult-to-solve problems, such as excessive pesticide residues in agricultural products, ecological pollution, the occurrence of pest resistance, and threats to human health. At the same time, due to the high cost, high risk, and long cycle of synthesizing new pesticides, it is difficult to meet people's demand for efficient and safe pesticides in the short term. The research on pesticide formulations is an important aspect of pesticide development. A good formulation can maximize the function of the active ingredients, cover the target to the greatest extent, reduce the amount of pesticides used, facilitate the use of pesticides, and reduce the impact on the environment.

[0003] Pesticide suspension is a dispersion system formed by dispersing water-insoluble solid raw materials in water. It is between colloidal dispersion system and coarse dispersion system. It mostly shows non-Newtonian fluid properties in rheology and is unstable in both dynamics and thermodynamics. In this system, the finer the particles, the larger their surface area, and they will inevitably develop in the direction of agglomeration to reduce the surface area, resulting in particle agglomeration. In order to increase the stability of the suspension, a certain amount of suitable dispersant is usually required. Screening high-performance new wetting dispersants is of great significance.

[0004] Picoxystrobin is a mitochondrial respiration inhibitor, that is, it inhibits mitochondrial respiration by electron transfer between cytochrome b and C1, and prevents and treats foliar diseases of wheat such as leaf blight, leaf rust, glumes blight, brown spot, powdery mildew, etc. Tebuconazole belongs to the triazole fungicide, is a sterol demethylation inhibitor, and is a highly effective systemic fungicide used for seed treatment or foliar spraying of important economic crops. It can effectively prevent and treat various rusts, powdery mildew, web spot, root rot, fusarium head blight, smut and seed-borne ring spot of cereal crops, tea cake disease, banana leaf spot, etc. In the prior art (CN101849546A, CN103704218A, CN103719107A, CN103783047A), the compound combination of picoxystrobin and tebuconazole has been studied in depth, but the development of its preparation has not been studied. In the above documents, only a series of preparations such as suspensions are mentioned; however, the applicant found during the study that the preparations configured according to the above documents have the problems of condensation and bottoming during storage, particle size growth and crystal precipitation after hot storage; and after the hot storage accelerated test, the viscosity of the preparation becomes larger and the flow is difficult; the drug particles cannot be well attached after being washed by rainwater. Therefore, in view of the deficiencies in the prior art, it is urgent to develop a suspension formulation with excellent preparation performance and good biological activity for the picoxystrobin and tebuconazole combination. Summary of the invention

[0005] The object of the present invention is to provide A to solve the technical problem of instability of the suspension after hot storage in the prior art.

[0006] In order to solve the above technical problems, the present invention provides a picoxystrobin·tebuconazole suspension, which comprises the following components in percentage by weight: 5-15% of picoxystrobin, 15-25% of tebuconazole, 0.5-3% of hydroxypolyethylene oxide-nonionic block copolymer, 2-6% of polyaryl phenyl ether phosphate derivative, 1-3% of ethoxy / propoxy alcohol, 3-7% of ethylene glycol, 0.1-0.3% of bactericide BIT20, 0.01-0.1% of ethoxy-modified trisiloxane, 0.5-2% of alkoxylated ethylenediamine, 0.5-2% of magnesium aluminum silicate, 0.1-0.5% of xanthan gum, and deionized water to make up to 100%.

[0007] Preferably, 10% of picoxystrobin, 20% of tebuconazole, 1.5% of hydroxypolyethylene oxide-nonionic block copolymer, 4% of polyaryl phenyl ether phosphate derivative, 2% of ethoxy / propoxy alcohol, 5% of ethylene glycol, 0.15% of bactericide BIT20, 0.05% of ethoxy-modified trisiloxane, 1% of alkoxylated ethylenediamine, 1% of magnesium aluminum silicate, 0.15% of xanthan gum, and deionized water to make up to 100%.

[0008] The hydroxy polyethylene oxide-nonionic block copolymer is: Ethylan NS 500LQ Akzo Nobel;

[0009] The polyaryl phenyl ether phosphate derivative is SOROPHOR SC Solvay;

[0010] The ethoxylated / propoxylated alcohol is ANTAROX AL304 Solvay;

[0011] The alkoxylated ethylenediamine is TERWET1221 Huntsman;

[0012] The preparation method of the picoxystrobin·tebuconazole suspension concentrate of the present invention is to mix the original drug and the auxiliary materials according to a certain ratio with deionized water as a dispersion medium and perform wet ultrafine grinding for preparation; during grinding, zirconium oxide beads are added to the mixture, and the specific gravity thereof is 1-2 times the weight of the suspension concentrate itself; the mixture is ground at a high speed of 1500 r / min at room temperature to reduce the average particle size of the suspension concentrate to less than 3 μm; and after separating the zirconium beads, the pesticide suspension concentrate is obtained.

[0013] The picoxystrobin·tebuconazole suspension concentrate of the present invention is used for preventing and controlling crop diseases, and the preferred crop disease is rice false smut.

[0014] By adopting the above technical solution, the present invention has the following beneficial effects:

[0015] The preparation has excellent heat storage stability, no agglomeration and bottoming phenomenon occurs during the storage process, no particle size growth occurs after heat storage, no crystal precipitation occurs when placed at room temperature for 3 days after heat storage, and the viscosity and particle size after heat storage are basically consistent with those before heat storage; and the preparation has excellent resistance to rain erosion.

[0016] The prepared picoxystrobin·tebuconazole suspension has excellent control effect on rice false smut. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 : Particle size distribution of formula 1 before hot storage;

[0018] Figure 2 : Particle size distribution of formula 1 after thermal storage;

[0019] Figure 3 : Particle size distribution of formula 2 before thermal storage;

[0020] Figure 4 : Particle size distribution of formula 2 after thermal storage;

[0021] Figure 5 : Crystal precipitation of formula 3;

[0022] Figure 6 : Rain water brush resistance test;

[0023] Figure 7 : The appearance of the preparation in Example 1 after hot storage is uniformly dispersed, without stratification and crusting;

[0024] Figure 8 : Comparative Example 1 was layered and crusted after hot storage;

[0025] Fig. 9 : Room temperature crystal properties of formula 2 under microscope;

[0026] Fig.10 : Crystal properties of formula 2 after thermal storage under microscope; DETAILED DESCRIPTION

[0027] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0028] The present invention is further explained below in conjunction with specific implementation modes.

[0029] Example 1: Preparation of suspension

[0030] Experimental Materials and Methods

[0031] Experimental materials: picoxystrobin, tebuconazole, hydroxy polyethylene oxide-nonionic block copolymer (Ethylan NS500LQ), Tersperse4894, MorwetD-425, polyaryl phenyl ether phosphate derivative (SOROPHOR SC), Agrlian-700, sodium lignin sulfonate, ethoxy / propoxy alcohol (ANTAROX AL304), ethylene glycol, fungicide: BIT20, ethoxy-modified trisiloxane, alkoxylated ethylenediamine (TERWET 1221), magnesium aluminum silicate, xanthan gum, deionized water;

[0032] Main experimental instruments: electronic balance, CX31 microscope, JL-1156 laser particle size distribution tester, sand mill, etc.

[0033] Preparation method: The pesticide formulation is prepared by mixing the original drug, dispersant, antifreeze agent, thickener, defoamer, etc. in a certain proportion with water as the dispersion medium and performing wet ultrafine grinding. When grinding, zirconium oxide beads are added to the mixture, and the specific gravity is 1.5 times the weight of the suspension agent itself. The average particle size of the suspension agent is reduced to less than 3μm by high-speed grinding at room temperature at a rate of 1500r / min. The pesticide suspension agent can be obtained after separating the zirconium beads.

[0034] Determination method:

[0035] Particle size determination: Take 2g of pesticide suspension and dilute it slightly, then slowly add it dropwise into the sample pool of the laser particle size analyzer while stirring, keeping the concentration between 50% and 80%. After it is completely dispersed by ultrasound, use a laser to shoot through the circulation pool to measure the relevant particle size, and finally obtain the average value of the preparation, D10, D50, D90 and other data related to the particle size.

[0036] Thermal storage stability determination: 1000 g of suspension sample was placed in a test container at room temperature, sealed and placed in a constant temperature oven at 54±2°C for 14 days, then taken out and the physical properties of the preparation (particle size change before and after thermal storage) were determined.

[0037] Results and Analysis

[0038] 1.1 Effect of ethoxylated / propoxylated alcohol on the suspended particle size distribution before and after thermal storage

[0039] Table 1 Suspension formulation composition

[0040]

[0041] Figure 1 It represents the particle size distribution of formula 1 before heat storage; Figure 2 is the particle size distribution of formula 1 after hot storage; Figure 3 It represents the particle size distribution of formula 2 before heat storage; Figure 4The particle size distribution after heat storage of formula 2. By comparison, it can be seen that adding ethoxylated / propoxylated alcohol to the suspension formulation can significantly improve the stability of the suspension after heat storage, so that the particle size of the suspension before and after heat storage remains basically the same.

[0042] 1.2 Effect of dispersant type on crystal growth before and after thermal storage.

[0043] Table 2 Suspension formulation composition

[0044]

[0045] After the hot storage, the suspension was returned to room temperature for 3 days and then passed through a 75 μm test sieve. No crystals were precipitated in formulation 2, while crystals precipitated to varying degrees in formulations 3 and 4. Figure 5 The crystal precipitation of formula 3. During the development process or storage of the suspension, due to the unreasonable compatibility of the dispersant, the crystal growth phenomenon of varying degrees will occur with the change of time and temperature, resulting in the product sedimentation, bottoming, and even paste problems. The present invention selects a hydroxy polyethylene oxide-nonionic block copolymer with strong adsorption force on particles to solve the problem of particle size growth and crystal precipitation after hot storage.

[0046] 1.3 Effect of alkoxylated ethylenediamine on the rheological properties of suspension concentrate after hot storage

[0047] Table 3 Suspension formulation composition and viscosity

[0048]

[0049] After testing, the viscosity of the suspension after hot storage of formula 2 was 1029mPa.s; the viscosity of the suspension after hot storage of formula 3 was 2534mPa.s. After the hot storage accelerated test, the suspension system showed that the viscosity of the preparation increased and the flow was difficult. In order to change the rheological properties, while ensuring that the type and relevant proportion of the thickener remain unchanged, alkoxylated ethylenediamine was added to control its corresponding apparent viscosity, making it easier to pour the product during use, with less residue after pouring (reducing waste), and no stratification during storage and transportation.

[0050] 1.4 Effect of dispersant type on the rainwater erosion resistance of suspension concentrate

[0051] Table 4 Suspension formulation composition

[0052]

[0053]

[0054] Test method: Dilute the sample in a pigment aqueous solution at a 1% mass concentration, drop 0.1g to 0.5 equal amounts of the sample on the leaf surface, leave it at room temperature for 2 hours, then use a spray device to simulate heavy rain at a rate of 0.5L / min, and observe the effect of the spraying after spraying for 5min, 10min, 15min, and 20min.

[0055] During the use of suspension concentrates, most plant stems and leaves often have a highly hydrophobic wax layer on their surface, which is difficult to wet with water. In addition, most chemical pesticides themselves are difficult to dissolve or insoluble in water, and wetting agents are needed to help the efficacy of the pesticides be exerted. Figure 6 The left leaf in the middle is recipe 2, and the right leaf is recipe 6; Figure 6 It can be seen that the left leaf adheres better after being washed by water. That is, compared with Agrlian-700 and sodium lignin sulfonate, the addition of polyaryl phenyl ether phosphate derivatives can reduce the interfacial tension between the plant and the pesticide solution, strengthen the wetting and spreading effect of the pesticide droplets, and make the pesticide particles still adhere well after being washed by rainwater, so as to better exert the efficacy.

[0056] 1.5 Performance measurement of suspension concentrate of formula 2 before and after heat storage

[0057] Table 5 Performance comparison of suspension concentrate before and after thermal storage

[0058]

[0059]

[0060] As shown in Table 5, the suspension prepared by Formula 2 of the present invention has excellent stability before and after heat storage. Figure 7 It shows that the appearance of the preparation of formula 2 after hot storage is uniformly dispersed, without stratification and skinning. Fig. 9 The room temperature crystal properties of formula 2 under a microscope; Fig.10 This is the crystal characteristics of formula 2 after heat storage under a microscope; the particle size remains basically constant.

[0061] Figure 8 It shows that formula 1 is layered and crusted after hot storage.

[0062] Example 2 Field test on the efficacy of 30% picoxystrobin·tebuconazole suspension against rice false smut

[0063] 2.1 Test agents and sources

[0064]

[0065] 2.2 Experimental crops and subjects Rice - Rice false smut

[0066] 2.3 Experimental methods and design

[0067] 2.3.1 Experimental treatment

[0068]

[0069] 2.3.2. Plot arrangement and repetition, application period, application method and application frequency

[0070] There were 11 treatments and 4 replications in the test area. The plot area was 25m2 and arranged in random blocks. The spray was applied at the early stage of rice false smut and then again after 7 days for a total of 2 applications.

[0071] 2.3.3 Prevention effectiveness investigation

[0072] The rice false smut was investigated after the clear water control was stable. The investigation method referred to the disease index of rice false smut (NY / T 1464.54—2014).

[0073]

[0074] Control effect = (disease index after control application - disease index after treatment application) / disease index after control application * 100.

[0075] 2.4 Results and Analysis

[0076] Compared with formulations 3, 6 and known agents, the 30% picoxystrobin·tebuconazole suspension prepared in formulation 2 can significantly improve its control effect on rice false smut, and the recommended dosage is 20-30 ml / mu.

[0077]

[0078]

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit it.

Claims

1. A picoxystrobin-tebuconazole suspension, characterized in that: The invention comprises the following components in percentage by weight: 10% of picoxystrobin, 20% of tebuconazole, 1.5% of hydroxy polyethylene oxide-nonionic block copolymer, 4% of polyaryl phenyl ether phosphate derivative, 2% of ethoxy / propoxy alcohol, 5% of ethylene glycol, 0.15% of fungicide BIT20, 0.05% of ethoxy-modified trisiloxane, 1% of alkoxylated ethylenediamine, 1% of magnesium aluminum silicate, 0.15% of xanthan gum, and deionized water to make up to 100%; The hydroxy polyethylene oxide-nonionic block copolymer is Ethylan NS 500LQ; the polyaryl phenyl ether phosphate derivative is SOROPHOR SC; the ethoxy / propoxy alcohol is ANTAROX AL304; and the alkoxylated ethylenediamine is TERWET1221.

2. The picoxystrobin-tebuconazole suspension according to claim 1, characterized in that The preparation method is as follows: the original drug and the auxiliary materials are mixed in proportion with deionized water as the dispersion medium and then wet-milled for ultrafine grinding. During the milling, zirconium oxide beads are added to the mixture, and the specific gravity thereof is 1-2 times of the weight of the suspension agent itself. The mixture is milled at a high speed of 1500 r / min at room temperature to reduce the average particle size of the suspension agent to less than 3 μm. After separating the zirconium oxide beads, the pesticide suspension agent is obtained.

3. Use of the picoxystrobin-tebuconazole suspension concentrate according to any one of claims 1 to 2 for preventing and controlling crop diseases.

4. The use according to claim 3, characterized in that The crop disease is rice false smut.

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