A suspension concentrate containing prohexadione calcium and its preparation method

Abstract

The present invention belongs to the field of plant growth regulators, and specifically relates to a suspension concentrate containing prohexadione calcium and a preparation method thereof. The suspension concentrate containing prohexadione calcium is mainly composed of water and the following components in percentage by mass: 1-5% prohexadione calcium, 0.1-0.5% 2,4-dichlorobenzamidocyclopropionic acid, 0.5-4% wetting agent, 0.3-3% dispersant, and 0.1-0.5% pH regulator; the pH regulator adjusts the pH of the suspension concentrate system to 7-9. The suspension concentrate containing prohexadione calcium of the present invention is a composite suspension formulation designed for the novel green plant growth regulator prohexadione calcium and 2,4-dichlorobenzamidocyclopropionic acid. The preparation has a high suspension rate, good low-temperature stability and heat storage stability during storage and use after dilution with water, and can maintain the stable efficacy of prohexadione calcium and 2,4-dichlorobenzamidocyclopropionic acid.

Description

Technical Field

[0001] The invention belongs to the field of plant growth regulators, and particularly relates to a suspension concentrate containing prohexadione calcium and a preparation method thereof. Background Art

[0002] Prohexadione calcium is a green plant growth regulator. Compared to quaternary ammonium salt and triazole retardants, it is safer for plants and has no residual toxicity to rotating crops. It also exhibits significant disease, insect, and stress resistance, and has a wide range of applications. Chinese patent document CN111869666A discloses a method for preparing a prohexadione calcium suspension concentrate. This suspension concentrate utilizes a composite dispersant component, a wetting dispersant, and a thickener to enhance dispersibility and stability. Even with an effective prohexadione calcium content of only 10 wt%, the suspension concentrate exhibits excellent growth-regulating properties for peanuts.

[0003] To maximize the efficacy of prohexadione calcium and its role in regulating plant growth, it is often necessary to compound it with other relevant ingredients to achieve even better growth regulation. 2,4-Dichlorobenzamidocyclopropionic acid is a new plant growth regulator that is effective in improving crop growth and quality in adverse growth environments, and can increase yields per unit area in low- and medium-yield fields.

[0004] The combined use of calcium prohexadione and 2,4-dichlorobenzamidocyclopropionic acid can significantly improve the stress resistance and yield increase of crops, and help improve the physiological growth of crops. However, 2,4-dichlorobenzamidocyclopropionic acid itself is almost insoluble in water. When used in combination, it needs to be dispersed in water with calcium prohexadione to obtain a stable system. How to maintain the stability of calcium prohexadione and 2,4-dichlorobenzamidocyclopropionic acid during storage and dilution after the combination is a problem that needs to be solved urgently. Therefore, it is necessary to develop a combined preparation of calcium prohexadione and 2,4-dichlorobenzamidocyclopropionic acid to give full play to its growth regulating effect on crops and ultimately achieve the goal of increasing production and income. Summary of the Invention

[0005] The object of the present invention is to provide a suspension concentrate containing prohexadione calcium, which has a high suspension rate during storage and use after adding water, and has good low-temperature stability and heat storage stability.

[0006] The second object of the present invention is to provide a method for preparing the above-mentioned suspension concentrate containing prohexadione calcium.

[0007] To achieve the above object, the technical solution of the prohexadione-calcium suspending agent of the present invention is:

[0008] A suspending agent containing prohexadione calcium mainly consists of water and the following components in percentage by mass: 1-5% of prohexadione calcium, 0.1-0.5% of 2,4-dichlorobenzamidocyclopropionic acid, 0.5-4% of a wetting agent, 0.3-3% of a dispersant, and 0.1-0.5% of a pH regulator; the pH regulator is used to adjust the pH of the suspending agent system to 7-9.

[0009] Suspension concentrates are composed of a solid technical with low water solubility and a high melting point, added to a suitable wetting agent, dispersant, viscosity enhancer, antifreeze agent, and water. The product is wet-ground in a sand mill to achieve a suspension formulation with a particle size of 0.5 to 5 μm. The formulation maintains high suspension properties after dilution with water. The formulation can be directly diluted with water and sprayed, depending on the dosage.

[0010] The suspension concentrate containing prohexadione calcium obtained by the present invention has excellent properties, including a high suspension rate of prohexadione calcium and 2,4-dichlorobenzamidocyclopropionic acid, a low residue content after pouring and washing, a high pass rate through a standard sieve with an aperture of 75 μm, and a low foam volume in a persistent foaming test; no stratification occurs after cold storage at 0±2°C for 7 days or storage at 54±2°C for 14 days; low-temperature stability and hot storage stability tests meet the national standards for suspension preparations and liquid preparations in my country, showing excellent low-temperature stability and hot storage stability, and being adaptable to reservoir conditions in various regions of my country with large temperature differences between north and south, maintaining the stable pharmacological effects of prohexadione calcium and 2,4-dichlorobenzamidocyclopropionic acid, and ensuring that the pharmacological effects of the suspension concentrate are not affected even after long-term storage.

[0011] The wetting agent reduces the surface tension or interfacial tension of prohexadione calcium and 2,4-dichlorobenzamidocyclopropionic acid, allowing water to spread on the surface or penetrate the surface, thereby effectively improving the wetting rate of the preparation and facilitating the processing and use of the preparation. Preferably, the wetting agent is selected from one or more of alkyl sulfonates, sulfates, polyoxyethylene-polyoxypropylene copolymers, polyoxyethylene ethers, and isodecyl alcohol polyoxyethylene ethers.

[0012] More preferably, the wetting agent is selected from one or more of YUS-SXC (sulfonates), YUS-A51G (sulfonates), YUS-FS7PG (sulfates), YUS-5050PB (polyoxyethylene polyoxypropylene copolymer), YUS-D1109S (polyoxyethylene ether), and RHODASURF 860 / P (isodecyl alcohol polyoxyethylene ether).

[0013] The dispersant can effectively improve the dispersion effect of the preparation in water and facilitate the application of the preparation. Preferably, the dispersant is selected from one or more of lignin sulfonate, polynaphthalene formaldehyde sulfonate, polycarboxylates, and alkylnaphthalene sulfonate.

[0014] More preferably, the dispersant is selected from one or more of YUS-RXB (lignin sulfonate), YUS-WG4 (lignin sulfonate), YUS-207K (polynaphthalene formaldehyde sulfonate), K77S (polycarboxylates), and MNS90 (alkyl naphthalene sulfonate).

[0015] By adding a pH regulator, the heat storage decomposition rate of the active ingredient can be effectively reduced and the heat storage stability of the preparation can be improved. Preferably, the pH regulator is selected from one or more of ethanolamine, sodium hydroxide, and potassium hydroxide.

[0016] In order to further increase the suspension rate of prohexadione calcium and 2,4-dichlorobenzamidocyclopropionic acid in the suspending agent and improve the pourability, sustained foaming, low-temperature stability and heat storage stability of the suspending agent system, preferably, the above-mentioned suspending agent is mainly composed of water and the following components in the following percentages: 1-5% prohexadione calcium, 0.1-0.5% 2,4-dichlorobenzamidocyclopropionic acid, 3-3.5% wetting agent, 2.5-3% dispersant, and 0.1-0.3% pH regulator; the pH regulator adjusts the pH of the suspending agent system to 7-9.

[0017] Preferably, the wetting agent is isodecyl alcohol polyoxyethylene ether, and the dispersant is one of polynaphthalene formaldehyde sulfonate and polycarboxylates; more preferably, the wetting agent is RHODASURF 860 / P (isodecyl alcohol polyoxyethylene ether), and the dispersant is one of YUS-207K (polynaphthalene formaldehyde sulfonate) and K77S (polycarboxylates).

[0018] The thickener can effectively improve the heat storage stability and fluidity of the suspension. Preferably, the suspension containing prohexadione-calcium includes a thickener; the mass percentage of the thickener in the suspension is 1.2-1.5%, and the thickener is magnesium aluminum silicate and xanthan gum, and the mass ratio of magnesium aluminum silicate to xanthan gum is 0.8-1:0.2-0.6.

[0019] Preferably, the mass percentage of the antifreeze in the suspending agent is 4 to 4.5%, and the antifreeze is selected from one of ethylene glycol, propylene glycol, and glycerol.

[0020] Preservatives can effectively improve the stability of the suspension by inhibiting the production of microorganisms. Preferably, the suspension containing prohexadione calcium includes one or both of a defoaming agent and a preservative; the defoaming agent is selected from one of organosiloxane, silicone, and tributyl phosphate; and the preservative is selected from one or both of kasone and sodium benzoate.

[0021] The present invention achieves the pharmacological stability of prohexadione calcium and 2,4-dichlorobenzamidocyclopropionic acid when stored in different environments by compounding prohexadione calcium and 2,4-dichlorobenzamidocyclopropionic acid, and can bring into play the synergistic effect of the two in regulating plant growth. The prepared suspension concentrate has the advantages of high suspension rate, good physical stability, good stability after dilution with water, strong adhesion, not being easily washed away by rainwater, low cost, safe production, storage and transportation, and convenient use.

[0022] The technical solution of the preparation method of the prohexadione-calcium suspension concentrate of the present invention is:

[0023] A preparation method of a suspension concentrate containing prohexadione calcium, comprising the following steps: uniformly mixing prohexadione calcium, 2,4-dichlorobenzamidocyclopropionic acid, a wetting agent, a dispersant, a pH regulator and other additives, and grinding the mixture to obtain the suspension concentrate; the particle size D of the material obtained after grinding is 90 ≤5μm.

[0024] Preferably, the grinding includes coarse grinding with a colloid mill and fine grinding with a sand mill.

[0025] The preparation method of the prohexadione calcium-containing suspension concentrate of the present invention has the advantages of safe preparation process, simple technology and stable product performance. DETAILED DESCRIPTION

[0026] The embodiments of the present invention are further described below with reference to specific examples. Unless otherwise specified, the wetting agents, dispersants, pH regulators, thickeners, defoamers, antifreeze agents, preservatives, etc. involved in the following examples are all commercially available conventional products.

[0027] Prohexadione calcium of the present invention belongs to the cyclohexanecarboxylic acid class plant growth retardant. As a green plant growth regulator, its action characteristic is the same as that of plant growth regulators such as paclobutrazol, uniconazole and trinexapac-ethyl, all of which inhibit the biosynthesis of gibberellic acid in plants, thus dwarfing crops and controlling plant growth. Compared with quaternary ammonium salts and triazole retardants, it mainly inhibits GA1, which controls the elongation growth of stems and leaves, shortens the stem elongation of many plants, but has no effect on GA4, which controls flower bud differentiation and grain development. Therefore, it is safer. Moreover, the half-life of prohexadione calcium in soil does not exceed 24 hours, and it has no residual toxicity to rotation plants, is environmentally friendly, and will not affect the next crop, thus having a very wide range of application prospects. Simultaneously, prohexadione calcium can have a wide range of regulatory effects on plant hormones such as active gibberellins, ethylene, auxin, salicylic acid, and abscisic acid, and has significant disease resistance, insect resistance and stress resistance. Preferably, the prohexadione calcium is a high-purity technical drug with a content of 92% produced by Zhengzhou Zhengshi Chemical Products Co., Ltd.

[0028] The 2,4-dichlorobenzamidocyclopropionic acid described in the present invention belongs to an aromatic carboxamidocyclopropionic acid. The Chinese invention patent with publication number CN102391147B discloses the preparation method and biological activity of this type of compound. It has a good effect on improving the growth potential, fruit set rate and quality of crops in adverse growth environments such as low temperature, drought, spring cold, salinization, pests and diseases. By promoting the accumulation of ABA in the plant body, it induces the expression of ABA response element genes, thereby generating resistance to adversity and reducing the use of chemical pesticides.

[0029] In some embodiments, the suspension concentrate containing prohexadione calcium is composed of the following components in mass percentage: 1-5% prohexadione calcium, 0.1-0.5% 2,4-dichlorobenzamidocyclopropionic acid, 0.5-4% wetting agent, 0.3-3% dispersant, 0.1-0.5% pH regulator, 1.2-2% thickener, 4-4.5% antifreeze, 0.05-0.2% defoaming agent, 0.1-0.3% preservative, and the balance is deionized water; the pH regulator adjusts the pH of the suspension concentrate system to 7-9.

[0030] Preferably, the suspending concentrate containing prohexadione calcium is composed of the following components in percentage by mass: 1-5% prohexadione calcium, 0.1-0.5% 2,4-dichlorobenzamidocyclopropionic acid, 3-3.5% wetting agent, 2.5-3% dispersant, 0.1-0.3% pH regulator, 1.2-1.5% thickener, 4-4.5% antifreeze, 0.05-2% defoaming agent, 0.1-0.3% preservative, and the balance is deionized water; the pH regulator adjusts the pH of the suspending concentrate system to 7-9.

[0031] In order to make the components in the suspension concentrate system mix more evenly and thoroughly, preferably, the preparation method of the suspension concentrate containing prohexadione calcium comprises the following steps:

[0032] 1) Prefabricated thickener mother liquor

[0033] 24 to 48 hours before the suspension preparation, add the thickener and preservative into deionized water and stir mechanically every 6 to 10 hours. The swollen thickener mother liquor should be a uniform translucent viscous liquid without lumps.

[0034] 2) Raw material mixing

[0035] Add deionized water to the mixing kettle, start stirring, and add liquid additives, wetting agent, antifreeze, defoaming agent, and pH adjuster in sequence. Stir for 20 to 30 minutes after the addition is completed; then add solid additives, dispersant, and thickener in sequence. Stir for 20 to 25 minutes after the addition is completed to obtain a mixed solution;

[0036] Adding calcium prohexadione and 2,4-dichlorobenzamidocyclopropionic acid to the mixed solution, turning on shearing, and shearing for 30 to 40 minutes while stirring to ensure that the raw materials are fully mixed and evenly dispersed, then adding the thickener mother solution prepared in step 1), and continuing stirring and shearing for 20 to 30 minutes to obtain a mixed material;

[0037] 3) Coarse grinding and fine grinding of mixed materials

[0038] The mixed material is coarsely ground by a colloid mill and then finely ground by a three-stage sand mill. The final particle size D 90 ≤5μm, that is, a suspension containing prohexadione calcium is obtained.

[0039] 1. Specific embodiments of the prohexadione-calcium suspension concentrate of the present invention

[0040] Example 1

[0041] The composition of the suspension concentrate containing prohexadione calcium in this embodiment is shown in Table 1 below.

[0042] Table 1 Composition of the suspension concentrate containing prohexadione calcium in Example 1

[0043] Components Content (weight percentage) Prohexadione calcium 4.9％ 2,4-Dichlorobenzamidocyclopropionic acid 0.1％ RHODASURF 860 / P 3％ YUS-207K 3％ magnesium aluminum silicate 1％ Xanthan gum 0.5％ Casson 0.05％ Ethanolamine 0.1％ Organosiloxane 0.05％ Ethylene glycol 4％ water Top up to 100%

[0044] Example 2

[0045] The composition of the suspension concentrate containing prohexadione calcium in this embodiment is shown in Table 2 below.

[0046] Table 2 Composition of the suspension concentrate containing prohexadione calcium of Example 2

[0047] Components Content (weight percentage) Prohexadione calcium 4.9％ 2,4-Dichlorobenzamidocyclopropionic acid 0.1％ RHODASURF 860 / P 3％ YUS-207K 2.5％ magnesium aluminum silicate 1％ Xanthan gum 0.5％ Casson 0.05％ Ethanolamine 0.1％ Organosiloxane 0.05％ Ethylene glycol 4％ water Top up to 100%

[0048] Example 3

[0049] The composition of the suspension concentrate containing prohexadione calcium in this embodiment is shown in Table 3 below.

[0050] Table 3 Composition of the suspension concentrate containing prohexadione calcium of Example 3

[0051] Components Content (weight percentage) Prohexadione calcium 4.5％ 2,4-Dichlorobenzamidocyclopropionic acid 0.5％ RHODASURF 860 / P 3.5％ YUS-207K 3％ magnesium aluminum silicate 1.0％ Xanthan gum 0.3％ Casson 0.05％ Ethanolamine 0.1％ Organosiloxane 0.05％ Ethylene glycol 4％ water Top up to 100%

[0052] Example 4

[0053] The composition of the suspension concentrate containing prohexadione calcium in this embodiment is shown in Table 4 below.

[0054] Table 4 Composition of the suspension formulation containing prohexadione calcium of Example 4

[0055] Components Content (weight percentage) Prohexadione calcium 4％ 2,4-Dichlorobenzamidocyclopropionic acid 0.2％ RHODASURF 860 / P 3.5％ YUS-207K 2.5％ magnesium aluminum silicate 1.0％ Xanthan gum 0.4％ Casson 0.05％ Ethanolamine 0.1％ Organosiloxane 0.05％ Ethylene glycol 4％ water Top up to 100%

[0056] Example 5

[0057] The composition of the suspension concentrate containing prohexadione calcium in this embodiment is shown in Table 5 below.

[0058] Table 5 Composition of the suspension formulation containing prohexadione calcium of Example 5

[0059]

[0060]

[0061] Example 6

[0062] The composition of the suspension concentrate containing prohexadione calcium in this embodiment is shown in Table 6 below.

[0063] Table 6 Composition of the suspension concentrate containing prohexadione calcium of Example 6

[0064] Components Content (weight percentage) Prohexadione calcium 2.5％ 2,4-Dichlorobenzamidocyclopropionic acid 0.5％ RHODASURF 860 / P 3％ YUS-207K 2.5％ magnesium aluminum silicate 1.0％ Xanthan gum 0.2％ Casson 0.05％ Ethanolamine 0.1％ Organosiloxane 0.05％ Ethylene glycol 4％ water Top up to 100%

[0065] Example 7

[0066] The composition of the suspension concentrate containing prohexadione calcium in this embodiment is shown in Table 7 below.

[0067] Table 7 Composition of the suspension concentrate containing prohexadione calcium of Example 7

[0068]

[0069]

[0070] 2. Specific Examples of the Preparation Method of the Prohexadione-Calcium Suspension Concentrate of the Present Invention

[0071] Example 8

[0072] The preparation method of the suspension concentrate containing prohexadione calcium in this embodiment describes the preparation process of the suspension concentrate of Examples 1-2, and specifically comprises the following steps:

[0073] 1) Prefabricated thickener mother liquor

[0074] 24 hours before the start of suspension preparation, add thickener and preservative into deionized water and stir mechanically every 8 hours. The swollen thickener mother liquor should be a uniform translucent viscous liquid without lumps.

[0075] 2) Raw material mixing

[0076] Add deionized water to the mixing kettle, start stirring, and add liquid additives, wetting agent, antifreeze, defoaming agent, and pH adjuster in sequence. Stir for 30 minutes after the addition is completed; then add solid additives, dispersant, and thickener in sequence. Stir for 20 minutes after the addition is completed to obtain a mixed solution;

[0077] Calcium prohexadione and 2,4-dichlorobenzamidocyclopropionic acid were added to the mixed solution, and shearing was started. The shearing was performed for 40 minutes while stirring to ensure that the raw materials were fully mixed and evenly dispersed. The thickener mother solution prepared in step 1) was added, and stirring and shearing were continued for 30 minutes to obtain a mixed material.

[0078] 3) Coarse grinding and fine grinding of mixed materials

[0079] The mixed material is coarsely ground by a colloid mill and then finely ground by a three-stage sand mill. The final particle size D 90 ≤5μm, that is, a suspension containing prohexadione calcium is obtained.

[0080] Example 9

[0081] The preparation method of the suspension concentrate containing prohexadione calcium in this embodiment is to illustrate the preparation process of the suspension concentrate in Example 3, and specifically comprises the following steps:

[0082] 1) Prefabricated xanthan gum mother liquor

[0083] 24 hours before the start of suspension preparation, add xanthan gum and kasonite into deionized water and stir mechanically every 8 hours. The swollen xanthan gum mother liquor is a uniform translucent viscous liquid without lumps.

[0084] 2) Raw material mixing

[0085] Deionized water was added to a mixing kettle, stirring was started, and liquid additives RHODASURF 860 / P, ethylene glycol, organosiloxane, and ethanolamine were added in sequence, and stirred for 25 minutes after the addition was completed; then additives YUS-207K and magnesium aluminum silicate were added, and stirred for 25 minutes after the addition was completed to obtain a mixed solution;

[0086] Calcium prohexadione and 2,4-dichlorobenzamidocyclopropionic acid were added to the mixed solution, and shearing was started. The mixture was sheared for 35 minutes while stirring to ensure that the raw materials were fully mixed and evenly dispersed. The xanthan gum mother solution prepared in step 1) was then added, and stirring and shearing were continued for 30 minutes to obtain a mixed material.

[0087] 3) Coarse grinding and fine grinding of mixed materials

[0088] The mixed material is coarsely ground by colloid mill, and then three-stage sand grinding is performed. The final particle size of the sand-ground material is D 90 ≤5μm, and a suspension concentrate containing prohexadione calcium was obtained.

[0089] Example 10

[0090] The preparation method of the suspension concentrate containing prohexadione calcium in this embodiment describes the preparation process of the suspension concentrate of Example 4, and specifically comprises the following steps:

[0091] 1) Prefabricated xanthan gum mother liquor

[0092] 24 hours before the start of suspension preparation, add xanthan gum and kasonite into deionized water and stir mechanically every 8 hours. The swollen xanthan gum mother liquor is a uniform translucent viscous liquid without lumps.

[0093] 2) Raw material mixing

[0094] Deionized water was added to a mixing kettle, stirring was started, and liquid additives RHODASURF 860 / P, ethylene glycol, organosiloxane, and ethanolamine were added in sequence, and stirred for 20 minutes after the addition was completed; then additives YUS-207K and magnesium aluminum silicate were added, and stirred for 25 minutes after the addition was completed to obtain a mixed solution;

[0095] Adding calcium prohexadione and 2,4-dichlorobenzamidocyclopropionic acid to the mixed solution, turning on shearing, and shearing for 30 minutes during stirring to ensure that the raw materials are fully mixed and evenly dispersed, then adding the xanthan gum mother solution prepared in step 1), and continuing stirring and shearing for 30 minutes to obtain a mixed material;

[0096] 3) Coarse grinding and fine grinding of mixed materials

[0097] The mixed material is coarsely ground by colloid mill, and then three-stage sand grinding is performed. The final particle size of the sand-ground material is D 90 ≤5μm, and a suspension concentrate containing prohexadione calcium was obtained.

[0098] Example 11

[0099] The preparation method of the suspension concentrate containing prohexadione calcium in this embodiment is to illustrate the preparation process of the suspension concentrate of Example 5, and specifically comprises the following steps:

[0100] 1) Prefabricated xanthan gum mother liquor

[0101] 24 hours before the start of suspension preparation, add xanthan gum and kasonite into deionized water and stir mechanically every 8 hours. The swollen xanthan gum mother liquor is a uniform translucent viscous liquid without lumps.

[0102] 2) Raw material mixing

[0103] Deionized water was added to a mixing kettle, stirring was started, and liquid additives RHODASURF 860 / P, ethylene glycol, organosiloxane, and ethanolamine were added in sequence, and stirred for 25 minutes after the addition was completed; then additives YUS-207K and magnesium aluminum silicate were added, and stirred for 30 minutes after the addition was completed to obtain a mixed solution;

[0104] Adding calcium prohexadione and 2,4-dichlorobenzamidocyclopropionic acid to the mixed solution, turning on shearing, and shearing for 40 minutes while stirring to ensure that the raw materials are fully mixed and evenly dispersed, then adding the xanthan gum mother solution prepared in step 1), and continuing stirring and shearing for 25 minutes to obtain a mixed material;

[0105] 3) Coarse grinding and fine grinding of mixed materials

[0106] The mixed material is coarsely ground by colloid mill, and then three-stage sand grinding is performed. The final particle size of the sand-ground material is D 90 ≤5μm, and a suspension concentrate containing prohexadione calcium was obtained.

[0107] Example 12

[0108] The preparation method of the suspension concentrate containing prohexadione calcium in this embodiment is to illustrate the preparation process of the suspension concentrate of Example 6, and specifically comprises the following steps:

[0109] 1) Prefabricated xanthan gum mother liquor

[0110] 24 hours before the start of suspension preparation, add xanthan gum and kasonite into deionized water and stir mechanically every 8 hours. The swollen xanthan gum mother liquor is a uniform translucent viscous liquid without lumps.

[0111] 2) Raw material mixing

[0112] Deionized water was added to a mixing kettle, stirring was started, and liquid additives RHODASURF 860 / P, ethylene glycol, organosiloxane, and ethanolamine were added in sequence, and stirred for 20 minutes after the addition was completed; then additives YUS-207K and magnesium aluminum silicate were added, and stirred for 20 minutes after the addition was completed to obtain a mixed solution;

[0113] Adding calcium prohexadione and 2,4-dichlorobenzamidocyclopropionic acid to the mixed solution, turning on shearing, and shearing for 30 minutes during stirring to ensure that the raw materials are fully mixed and evenly dispersed, then adding the xanthan gum mother solution prepared in step 1), and continuing stirring and shearing for 20 minutes to obtain a mixed material;

[0114] 3) Coarse grinding and fine grinding of mixed materials

[0115] The mixed material is coarsely ground by colloid mill, and then three-stage sand grinding is performed. The final particle size of the sand-ground material is D 90 ≤5μm, and a suspension concentrate containing prohexadione calcium was obtained.

[0116] Example 13

[0117] The preparation method of the suspension concentrate containing prohexadione calcium in this embodiment is to illustrate the preparation process of the suspension concentrate of Example 7, and specifically comprises the following steps:

[0118] 1) Prefabricated xanthan gum mother liquor

[0119] 24 hours before the start of suspension preparation, add xanthan gum and kasonite into deionized water and stir mechanically every 8 hours. The swollen xanthan gum mother liquor is a uniform translucent viscous liquid without lumps.

[0120] 2) Raw material mixing

[0121] Deionized water was added to a mixing kettle, stirring was started, and liquid additives RHODASURF 860 / P, ethylene glycol, organosiloxane, and ethanolamine were added in sequence, and stirred for 25 minutes after the addition was completed; then additives YUS-207K and magnesium aluminum silicate were added, and stirred for 30 minutes after the addition was completed to obtain a mixed solution;

[0122] Adding calcium prohexadione and 2,4-dichlorobenzamidocyclopropionic acid to the mixed solution, turning on shearing, and shearing for 30 minutes during stirring to ensure that the raw materials are fully mixed and evenly dispersed, then adding the xanthan gum mother solution prepared in step 1), and continuing stirring and shearing for 25 minutes to obtain a mixed material;

[0123] 3) Coarse grinding and fine grinding of mixed materials

[0124] The mixed material is coarsely ground by colloid mill, and then three-stage sand grinding is performed. The final particle size of the sand-ground material is D 90 ≤5μm, and a suspension concentrate containing prohexadione calcium was obtained.

[0125] 3. Experimental Examples

[0126] In the following experimental examples, the following methods were used to test the suspension rate, pH value, pourability, persistent foaming, low temperature stability, and heat storage stability:

[0127] 1. The suspension rate shall be determined in accordance with 4.2 of GB / T 14825;

[0128] 2. The pH value shall be determined in accordance with GB / T 1601;

[0129] 3. The dumping test shall be carried out in accordance with GB / T 31737;

[0130] 4. The persistent foaming test shall be carried out in accordance with GB / T 28137;

[0131] 5. The wet sieving test shall be carried out in accordance with the "wet sieving method" in GB / T 16150;

[0132] 6. The low-temperature stability test is conducted according to the "Suspension Preparation" method in GB / T 19137. After cold storage at 0±2℃ for 7 days, the beaker is removed and returned to room temperature. The suspension rate is measured and the wet sieve test is performed. The product that meets the requirements of this standard is qualified.

[0133] 7. Thermal storage stability shall be determined according to the "Liquid Preparations" method in GB / T 19136. Measure 30 mL of sample and store at 54±2°C for 14 days. Remove and return to room temperature. For samples that have not changed in mass, determine the mass fraction of the active ingredient according to 4.3 within 24 hours. Samples that have a mass fraction of the active ingredient of no less than 95% of the pre-thermal storage value and meet the requirements of this standard for pH value, wet sieve test, suspension rate, and pourability shall be considered acceptable.

[0134] Experimental Example 1

[0135] This experimental example illustrates the results of the formulation screening of Example 1-2.

[0136] (1) Screening test of the suspension formulation containing prohexadione-calcium of Examples 1-2

[0137] The formulation screening process for suspension concentrates uses the following steps:

[0138] 1) Prefabricated thickener mother liquor

[0139] 24 hours before the start of suspension preparation, add thickener (xanthan gum) and preservatives (kasonon, sodium benzoate) into deionized water and stir mechanically every 8 hours. The swollen thickener mother liquor should be a uniform translucent viscous liquid without lumps.

[0140] 2) Raw material mixing

[0141] Deionized water was added to a mixing kettle, stirring was started, and liquid additives and wetting agents (YUS-SXC, YUS-A51G, YUS-FS7PG, YUS-5050PB, YUS-D1109S, RHODASURF 860 / P); antifreeze (ethylene glycol, propylene glycol, glycerol, urea); defoaming agents (organosiloxane, silicone, tributyl phosphate); pH adjusters (formic acid, acetic acid, citric acid, ethanolamine, sodium hydroxide) were added in sequence, and the mixture was stirred for 30 minutes after the addition was completed. Then, solid additives and dispersants (YUS-RXB, YUS-WG4, YUS-207K, K77S, MNS90) and thickeners (magnesium aluminum silicate, sodium carboxymethyl cellulose) were added in sequence, and the mixture was stirred for 20 minutes after the addition was completed to obtain a mixed solution.

[0142] Calcium prohexadione and 2,4-dichlorobenzamidocyclopropionic acid were added to the mixed solution, and shearing was started. The shearing was performed for 40 minutes while stirring to ensure that the raw materials were fully mixed and evenly dispersed. The thickener mother solution prepared in step 1) was added, and stirring and shearing were continued for 30 minutes to obtain a mixed material.

[0143] 3) Coarse grinding and fine grinding of mixed materials

[0144] The mixed material is coarsely ground by a colloid mill and then finely ground by a three-stage sand mill. The final particle size D90 ≤5μm, that is, a suspension containing prohexadione calcium is obtained.

[0145] (2) Screening results of the suspension formulation containing prohexadione-calcium of Example 1-2

[0146] 1.1 Antifreeze screening

[0147] Table 8 Screening test of antifreeze

[0148]

[0149]

[0150] Under the same conditions (0±2℃), use different antifreeze agents and place at low temperature to observe whether crystals are precipitated.

[0151] Table 9 Screening test results of antifreeze

[0152]

[0153] Combined with the above low-temperature tests, the addition of an antifreeze improves the low-temperature stability of the prohexadione-calcium suspension concentrate. However, urea is prone to crystallization at low temperatures. In Experiment 5, a small amount of crystals precipitated after 3 days at 0±2°C. Furthermore, due to the high price of propylene glycol and the high viscosity and inconvenience of glycerol, 4% ethylene glycol was preferred as the antifreeze.

[0154] 1.2 Screening of wetting agents

[0155] Table 10 Screening test of wetting agents

[0156]

[0157] On the basis of antifreeze screening, different wetting agents were added respectively, and the wetting phenomenon and persistent foaming of each sample were observed and measured to see whether the wetting time and foam volume were high.

[0158] Table 11 Screening test results of wetting agents

[0159]

[0160]

[0161] Combined with the above experiments, the addition of different wetting agents can effectively increase the wetting rate of the suspension concentrate, facilitating production and application. By comparing the persistent foaming properties of the samples, considering that high foaming volume can easily cause inconvenience in use, 4% RHODASURF 860 / P is preferred as the wetting agent.

[0162] 1.3 Screening of dispersants

[0163] Table 12 Screening test of dispersants

[0164]

[0165] Based on the screening of antifreeze and wetting agents, different dispersants were added respectively, and the water dispersion phenomenon of each sample was observed and measured.

[0166] Table 13 Screening test results of dispersants

[0167]

[0168]

[0169] Combined with the above experiments, by adding different dispersants, the water dispersion effect of the preparation can be effectively improved, which is convenient for the application of the suspension concentrate. According to the results of Experiment 4, the water dispersion is faster, and the 3% YUS-207K added in Experiment 4 is preferably used as the dispersant.

[0170] 1.4 Screening of defoaming agents

[0171] Table 14 Screening test of defoaming agent

[0172]

[0173] Based on the wetting agent RHODASURF 860 / P and dispersant YUS-207K, different defoaming agents were added respectively, the defoaming results of each sample were observed, and the foam volume was measured.

[0174] Table 15 Screening test results of defoamers

[0175] Test 1 Test 2 Test 3 Test 4 Test results Foam 33mL Foam 14mL Foam 21mL Foam 26mL

[0176] Combined with the above experiments, by adding different types of defoaming agents, the generation of foam can be effectively suppressed or eliminated. Considering factors such as high foam volume easily causing inconvenience in filling and flight control, the 0.05% organosiloxane used in Experiment 2 is preferably used as the defoaming agent.

[0177] 1.5 Screening of pH regulator

[0178] Table 16 Screening test of pH regulator

[0179]

[0180]

[0181] Because prohexadione calcium is stable under alkaline conditions and considering the stability of 2,4-dichlorobenzamidocyclopropionic acid, different pH adjusters were used to adjust the pH of the samples to a slightly alkaline level. The active ingredient content was measured after heat storage at 54°C for 14 days, and the decomposition rate of the active ingredient was calculated.

[0182] Table 17 Screening test results of pH regulators

[0183]

[0184]

[0185] In combination with the above experiments, by adding different pH adjusters and heat storing at 54±2°C for 14 days, the decomposition rate of each sample was measured. The decomposition rates of prohexadione calcium after adding ethanolamine and sodium hydroxide were 2.44% and 4.3% (less than 5%), respectively. At the same time, the decomposition rates of dichlorobenzamidocyclopropionic acid were 0.2% and 0.8%, respectively. The heat storage decomposition rate of the active ingredient can be effectively reduced, and the heat storage stability of the suspension can be improved. Compared with the decomposition rate of the active ingredient after adding the pH adjuster, the use of 0.1% ethanolamine is preferred.

[0186] 1.6 Thickener screening

[0187] Table 18 Screening test of thickeners

[0188]

[0189] On the basis of screening antifreeze, wetting and dispersing agent, pH regulator and defoaming agent, thickeners were added respectively to observe the pourability and thermal stability (degree of stratification) of the samples.

[0190] Table 19 Screening test results of thickeners

[0191]

[0192]

[0193] Combined with the above experiments, by adding different thickeners and heat storing at 54±2℃ for 14 days, the water extraction degree and pourability of each sample were measured. The appropriate ratio of xanthan gum and magnesium aluminum silicate can effectively improve the heat storage stability of the preparation and have good fluidity. The use of xanthan gum combined with magnesium aluminum silicate is preferred, with the addition amounts of 0.5% and 1%, respectively.

[0194] 1.7 Screening of preservatives

[0195] Table 20 Screening test of preservatives

[0196]

[0197] Based on the screening of antifreeze, wetting and dispersing agents, pH regulators, defoaming agents and thickeners, preservatives were added respectively to observe the antiseptic effects of the samples.

[0198] Table 21 Screening test results of preservatives

[0199]

[0200] Combined with the above experiments, by adding different preservatives and observing the preservative effect after storage at room temperature for 6 months, it was found that preservatives can effectively improve the stability of the preparation and inhibit the production of microorganisms. Considering that Kasong is easy to use and cost-effective as a liquid, Kasong with good cost-effectiveness is preferred, and the minimum addition amount is 0.05%.

[0201] 1.8 Screening of optimal addition amounts of wetting agents and dispersants

[0202] Table 22 Screening test of optimal addition amount of wetting agent and dispersant

[0203]

[0204] Table 23 Screening test results of optimal addition amount of wetting agent and dispersant

[0205]

[0206]

[0207] Combining the sample test results of Tests 1 to 12, and comprehensively considering the results of the pourability test, persistent foaming, low-temperature stability, hot storage stability, wet sieving test, etc., it can be concluded that Tests 8 and 9 are comprehensively judged to be qualified. In Test 9, the addition amounts of the wetting agent RHODASURF 860 / P and the dispersant YUS-207K are respectively 3%, i.e., Example 1; in Test 8, the addition amounts of the wetting agent RHODASURF 860 / P and the dispersant YUS-207K are respectively 3% and 2.5%, i.e., Example 2.

[0208] Experimental Example 2

[0209] This experimental example tests the performance of the suspending agents of Examples 3 to 6.

[0210] The performance test results of the suspending agents of Examples 3 to 6 are shown in Table 24.

[0211] Table 24 Performance test results of the suspending agents of Examples 3 to 6

[0212]

[0213] Combined with the sample test results, the pourability test, the persistent foaming test, the low temperature stability, the hot storage stability, the wet sieving test and other results, the suspension concentrates of Examples 3 to 6 were comprehensively judged to be qualified.

Claims

1. A suspension concentrate containing prohexadione calcium, characterized in that: The invention mainly consists of water and the following components in percentage by mass: 1-5% of prohexadione calcium, 0.1-0.5% of 2,4-dichlorobenzamidocyclopropionic acid, 3-3.5% of a wetting agent, 2.5-3% of a dispersant, and 0.1-0.5% of a pH regulator; the pH regulator is used to adjust the pH of the suspension system to 7-9; the wetting agent is polyoxyethylene isodecyl alcohol ether; and the dispersant is polynaphthalene formaldehyde sulfonate.

2. The prohexadione-calcium suspending concentrate according to claim 1, wherein The pH regulator is selected from one or more of ethanolamine, sodium hydroxide, and potassium hydroxide.

3. The prohexadione-calcium suspending concentrate according to claim 1, wherein The suspending agent mainly consists of water and the following components in percentages: 1-5% of prohexadione calcium, 0.1-0.5% of 2,4-dichlorobenzamidocyclopropionic acid, 3-3.5% of a wetting agent, 2.5-3% of a dispersant, and 0.1-0.3% of a pH regulator; the pH regulator adjusts the pH of the suspending agent system to 7-9.

4. The prohexadione-calcium suspending concentrate according to any one of claims 1 to 3, wherein The calcium prohexadione-containing suspending agent includes a thickener; the mass percentage of the thickener in the suspending agent is 1.2-1.5%, the thickener is magnesium aluminum silicate and xanthan gum, and the mass ratio of magnesium aluminum silicate to xanthan gum is 0.8-1:0.2-0.

6.

5. The prohexadione-calcium suspending concentrate according to claim 4, wherein The prohexadione-calcium suspending agent includes an antifreeze agent; the mass percentage of the antifreeze agent in the suspending agent is 4-4.5%, and the antifreeze agent is selected from one of ethylene glycol, propylene glycol, and glycerol.

6. The prohexadione-calcium suspending concentrate according to claim 4, wherein The suspending agent containing prohexadione calcium comprises one or both of a defoaming agent and a preservative; the defoaming agent is selected from one of organosiloxane, silicone and tributyl phosphate; the preservative is selected from one or both of kasone and sodium benzoate.

7. A method for preparing a suspension concentrate containing prohexadione-calcium according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: mixing calcium prohexadione, 2,4-dichlorobenzamidocyclopropionic acid, a wetting agent, a dispersant, a pH regulator and other additives uniformly, and grinding the mixture to obtain the product; the particle size D of the material obtained after the grinding is 90 ≤5μm.

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