Thiophanate-methyl-containing bactericide

Abstract

The invention discloses a thiophanate-methyl-containing bactericide, and belongs to the technical field of pesticides. The bactericide comprises a core material and a capsule wall material, the active components in the inner core material comprise thiophanate-methyl, quaternary ammonium salt, hexamethylenetetramine and tea saponin; the capsule wall material comprises chitosan, sodium lignin sulfonate and oxine-copper, and the capsule wall material coats the core material. The preparation method comprises the following steps: mixing thiophanate-methyl, quaternary ammonium salt, hexamethylenetetramine and tea saponin, adding Tween 80 and water to form a homogeneous emulsion, mixing a chitosan solution, sodium lignin sulfonate and oxine-copper to form a coating solution, dropwise adding the homogeneous emulsion into the coating solution, stirring, and spray-drying to obtain the granular bactericide. The comprehensive performance is improved through the combination of multi-stage synergistic sterilization and functional coating, the resistance of germs is weakened, and the activity of thiophanate-methyl to drug-resistant strains is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of pesticides, and particularly relates to a bactericide containing thiophanate-methyl. BACKGROUND

[0002] Bactericides can be divided into protective bactericides, eradicative bactericides, systemic bactericides and plant immune activators (antibiosis agents) according to the action mode, wherein the systemic bactericides can be absorbed by plants and conducted in the plant body, and can prevent and control diseases through chemical protection and chemical treatment, for example, kresoxim-methyl, trifloxystrobin, metalaxyl, thiophanate-methyl, thiophanate-methyl, etc., which have certain protection and treatment effects on some fungal diseases such as black spot, brown spot, anthracnose, powdery mildew, wilt, damping-off, black spot, stem rot, leaf spot, etc.

[0003] Thiophanate-methyl is a benzimidazole fungicide, and its action mechanism is to interfere with the formation of spindles in mitosis of the pathogen, thereby affecting cell division and inhibiting the normal growth of the pathogen. Common thiophanate-methyl fungicides include 50% and 70% wettable powders, 40% and 50% suspension concentrates, and 36% suspensions. These fungicides with different thiophanate-methyl contents and formulations are widely used in different crops and disease control.

[0004] Most of the existing thiophanate-methyl fungicides are single components, and long-term use of single chemical substances for disease and pest control will lead to decreased efficacy due to increased drug resistance. In order to achieve good fungicidal effect, the amount of drug will be gradually increased in practical application, and the pesticide residue problem caused by increasing the amount of drug will affect human health and the ecological environment, forming a vicious cycle. SUMMARY

[0005] The purpose of the present application is to provide a bactericide containing thiophanate-methyl, which can solve the problem of gradually decreasing efficacy of thiophanate-methyl fungicides in long-term application in the prior art.

[0006] The purpose of the present application can be achieved by the following technical solutions: A bactericide containing thiophanate-methyl, the bactericide comprising core material and wall material; the active components in the core material comprising thiophanate-methyl, quaternary ammonium salt, hexamethylenetetramine and tea saponin; the wall material comprising chitosan, sodium lignosulfonate and quinoline copper, and the wall material forming a coating on the core material.

[0007] The conventional thiophanate-methyl in the above active ingredients is the main fungicidal component, which is absorbed and conducted, inhibits β-tubulin polymerization, and blocks hypha division. The added quaternary ammonium salt can promote the penetration of thiophanate-methyl into the cell membrane and enter the cell, the slow hydrolysis of hexamethylenetetramine releases formaldehyde, denatures the protein of the fungus, weakens the resistance of the pathogen, and enhances the activity of thiophanate-methyl on drug-resistant strains. Tea saponin can not only be used as a natural surfactant, but also can target the destruction of fungal chitin-glucan complex, increase the permeability of the cell membrane or cell wall, and promote the penetration of thiophanate-methyl into the fungus. Tea saponin destroys the outer biological membrane, and quaternary ammonium salt is more likely to contact the cell membrane phospholipid, thereby accelerating the membrane disintegration. The permeability of thiophanate-methyl to drug-resistant strains is enhanced, and the drug resistance caused by β-tubulin mutation is overcome.

[0008] The chitosan in the capsule wall material can form a slow-release coating on the inner core material. Partial replacement of chitosan with partial sodium lignosulfonate can reduce the cost of raw materials while maintaining the integrity of the film. Copper quinolate can fill the pores of the chitosan film, control the slow release of the inner core, and improve the stability of the fungicide. On the other hand, copper quinolate can bind to the cell membrane of the pathogenic fungus, interfere with its metabolic process, and thereby inhibit the growth and reproduction of the pathogen.

[0009] Further, the preparation steps of the fungicide are as follows: S1, grind thiophanate-methyl and hexamethylenetetramine through a 200-mesh sieve, add quaternary ammonium salt and tea saponin, stir and mix uniformly, then add Tween 80 and water, stir and mix at 50-60°C to form a homogeneous emulsion; S2, dissolve chitosan in acetic acid solution to obtain a chitosan solution, add sodium lignosulfonate and copper quinolate, and ultrasonically disperse to form a coating liquid; S3, add the homogeneous emulsion to the coating liquid, stir at 40-50°C, adjust the pH to 6.0-6.5, and spray dry to obtain a granular fungicide.

[0010] In preparation, the active ingredients are first mixed uniformly, then the auxiliary agent Tween 80 and the solvent water are added, since the thiophanate-methyl in the active ingredients is difficult to dissolve in water, the amphiphilic property of the auxiliary agent Tween 80 and tea saponin can reduce the interfacial tension, promote the formation of stable emulsion, although tea saponin is a natural surfactant, but there are defects of strong foaming and insufficient emulsion stability when used alone, the use of Tween 80 can reduce the foam interference of tea saponin used alone, avoid the aggregation and precipitation of the core material, and ensure the uniformity of subsequent coating. The chitosan in the coating liquid is a film-forming agent, after adding sodium lignosulfonate and quinoline copper, the sodium lignosulfonate (negative) and the chitosan (positive) form a dense network through electrostatic self-assembly, and can form chelation and adsorption to quinoline copper, the capsule wall material can increase the viscosity of the dispersion liquid when the bactericide is prepared into a water dispersant, which is helpful for adhering to the plant leaves after spraying, forming a protective film, slowly releasing the active ingredients and copper ions, and inhibiting the invasion of exogenous pathogenic bacteria, improving the bactericidal effect.

[0011] Further, the mass concentration of thiophanate-methyl in the homogeneous emulsion is 40-50%.

[0012] Further, the mass concentration of hexamethylenetetramine in the homogeneous emulsion is 8-12%. Further, the quaternary ammonium salt is at least one of didecyldimethyl ammonium chloride, benzalkonium bromide and benzalkonium chloride.

[0013] Further, the mass concentration of the quaternary ammonium salt in the homogeneous emulsion is 10-15%. The mass concentration of tea saponin in the homogeneous emulsion is 3-8%.

[0014] Further, the mass concentration of Tween 80 in the homogeneous emulsion is 1-3%.

[0015] Further, the mass concentration of the acetic acid solution is 1-3wt%. The mass concentration of chitosan in the chitosan solution is 1-2wt%.

[0016] Further, the mass ratio of sodium lignosulfonate and chitosan is 0.2-0.4:1.

[0017] Further, the mass ratio of quinoline copper and chitosan is 1-1.3:2.

[0018] Further, the mass ratio of the homogeneous emulsion and the coating liquid is (6-8):(2-4).

[0019] Further, the particle size of the bactericide is 5-15μm.

[0020] The beneficial effects of the present application are: (1) The present application improves the comprehensive performance by combining multi-stage synergistic sterilization (chemical agent + natural active substance) with functional coating (slow release + targeting). On the basis of thiophanate-methyl sterilization, hexamethylenetetramine is added to slowly hydrolyze and release formaldehyde, denature the protein of the bacteria, weaken the resistance of the pathogenic bacteria, improve the activity of thiophanate-methyl on drug-resistant strains, and use quaternary ammonium salt and tea saponin to synergistically destroy the structure of the cell membrane or cell wall. Promote the entry of thiophanate-methyl into the cell, and overcome the decrease in drug efficacy caused by drug resistance of beta-tubulin mutation.

[0021] (2) The chitosan in the capsule wall material can form a slow-release coating on the inner core material, and part of the sodium lignosulfonate can replace part of the chitosan, which can reduce the cost of raw materials while maintaining the integrity of the film. Quinoline copper can fill the pores of the chitosan film on the one hand, control the slow release of the inner core, and improve the stability of the fungicide. On the other hand, the quinoline copper adsorbed by chitosan and sodium lignosulfonate is released slowly and combined with the cell membrane of the pathogenic bacteria, interfering with its metabolic process, thereby inhibiting the growth and reproduction of the pathogenic bacteria, and reducing the residual harm caused by free copper ions. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0023] Embodiment 1

[0024] The present embodiment provides a fungicide containing thiophanate-methyl, which comprises an inner core material and a capsule wall material; the active components in the inner core material include thiophanate-methyl, quaternary ammonium salt, hexamethylenetetramine and tea saponin; the capsule wall material includes chitosan, sodium lignosulfonate and quinoline copper, and the capsule wall material forms a coating on the inner core material.

[0025] The preparation steps of the fungicide are as follows: Step one, grind thiophanate-methyl and hexamethylenetetramine through a 200 mesh sieve, add benzalkonium bromide (quaternary ammonium salt) and tea saponin, stir and mix uniformly, then add Tween 80 and water, stir and mix at 50-60℃, to form a homogeneous emulsion. Among them, the mass concentration of thiophanate-methyl is 40%, the mass concentration of hexamethylenetetramine is 10%, the mass concentration of benzalkonium bromide is 10%, the mass concentration of tea saponin is 3%, the mass concentration of Tween 80 is 1%, and the rest is water.

[0026] Step two, dissolve chitosan in acetic acid solution with a mass concentration of 2wt%, obtain chitosan solution with a concentration of 2wt%, add sodium lignosulfonate and quinoline copper for ultrasonic dispersion, form a coating solution, the mass ratio of sodium lignosulfonate and chitosan is 0.2:1, the mass ratio of quinoline copper and chitosan is 1:2.

[0027] Step three, add the homogeneous emulsion to the coating solution, the mass ratio of the homogeneous emulsion and the coating solution is 7:3, constant temperature stirring at 50℃, adjust the pH to 6.5, spray drying to obtain granular bactericide, control the inlet air temperature of spray drying to be 120℃, the outlet air temperature to be 80℃, the obtained bactericide particle size is 5-15μm.

[0028] Example 2

[0029] The difference from example 1 is that the mass concentration of hexamethylenetetramine is increased from 10% to 12%.

[0030] The present embodiment provides a bactericide containing thiophanate-methyl, which comprises core material and capsule wall material; the active components in the core material include thiophanate-methyl, quaternary ammonium salt, hexamethylenetetramine and tea saponin; the capsule wall material includes chitosan, sodium lignosulfonate and quinoline copper, and the capsule wall material forms a coating on the core material.

[0031] The preparation steps of the bactericide are as follows: Step one, grind thiophanate-methyl and hexamethylenetetramine through a 200 mesh sieve, add benzalkonium bromide (quaternary ammonium salt) and tea saponin, stir and mix uniformly, then add Tween 80 and water, stir and mix at 50-60℃, form a homogeneous emulsion. Among them, the mass concentration of thiophanate-methyl is 40%, the mass concentration of hexamethylenetetramine is 12%, the mass concentration of benzalkonium bromide is 10%, the mass concentration of tea saponin is 3%, the mass concentration of Tween 80 is 1%, and the rest is water.

[0032] Step two, dissolve chitosan in acetic acid solution with a mass concentration of 2wt%, obtain chitosan solution with a concentration of 2wt%, add sodium lignosulfonate and quinoline copper for ultrasonic dispersion, form a coating solution, the mass ratio of sodium lignosulfonate and chitosan is 0.2:1, the mass ratio of quinoline copper and chitosan is 1:2.

[0033] Step three, add the homogeneous emulsion to the coating solution, the mass ratio of the homogeneous emulsion and the coating solution is 7:3, constant temperature stirring at 50℃, adjust the pH to 6.5, spray drying to obtain granular bactericide, control the inlet air temperature of spray drying to be 120℃, the outlet air temperature to be 80℃, the obtained bactericide particle size is 5-15μm.

[0034] Example 3

[0035] The difference from Example 1 is that the mass concentration of hexamethylenetetramine is reduced from 10% to 8%.

[0036] The present example provides a bactericide containing thiophanate-methyl, which comprises core material and capsule wall material; the active components in the core material comprise thiophanate-methyl, quaternary ammonium salt, hexamethylenetetramine and tea saponin; the capsule wall material comprises chitosan, sodium lignosulfonate and quinoline copper, and the capsule wall material forms a coating on the core material.

[0037] The preparation steps of the bactericide are as follows: Step one, grind thiophanate-methyl and hexamethylenetetramine through a 200-mesh sieve, add benzalkonium bromide (quaternary ammonium salt) and tea saponin, stir and mix uniformly, then add Tween 80 and water, stir and mix at 50-60°C to form a homogeneous emulsion. Among them, the mass concentration of thiophanate-methyl is 40%, the mass concentration of hexamethylenetetramine is 8%, the mass concentration of benzalkonium bromide is 10%, the mass concentration of tea saponin is 3%, the mass concentration of Tween 80 is 1%, and the rest is water.

[0038] Step two, dissolve chitosan in a 2wt% acetic acid solution to obtain a 2wt% chitosan solution, add sodium lignosulfonate and quinoline copper and ultrasonic dispersion to form a coating liquid, the mass ratio of sodium lignosulfonate to chitosan is 0.2:1, and the mass ratio of quinoline copper to chitosan is 1:2.

[0039] Step three, add the homogeneous emulsion to the coating liquid, the mass ratio of the homogeneous emulsion to the coating liquid is 7:3, constant temperature stirring at 50°C, adjust the pH to 6.5, spray drying to obtain a granular bactericide, control the inlet air temperature of spray drying to be 120°C and the outlet air temperature to be 80°C, and the obtained bactericide particle size is 5-15μm.

[0040] Example 4

[0041] The difference from Example 1 is that the mass concentration of benzalkonium bromide is increased from 10% to 12% and the mass concentration of tea saponin is increased from 3% to 5%.

[0042] The present example provides a bactericide containing thiophanate-methyl, which comprises core material and capsule wall material; the active components in the core material comprise thiophanate-methyl, quaternary ammonium salt, hexamethylenetetramine and tea saponin; the capsule wall material comprises chitosan, sodium lignosulfonate and quinoline copper, and the capsule wall material forms a coating on the core material.

[0043] The preparation steps of the bactericide are as follows: Step one, grinding thiophanate-methyl and methenamine through 200 mesh sieve, adding benzalkonium bromide (quaternary ammonium salt) and tea saponin, stirring and mixing evenly, then adding Tween 80 and water, stirring and mixing at 50-60℃, forming a homogeneous emulsion. Among them, the mass concentration of thiophanate-methyl is 40%, the mass concentration of methenamine is 10%, the mass concentration of benzalkonium bromide is 12%, the mass concentration of tea saponin is 5%, the mass concentration of Tween 80 is 1%, and the rest is water.

[0044] Step two, dissolve chitosan in a 2wt% acetic acid solution to obtain a 2wt% chitosan solution, add sodium lignosulfonate and quinoline copper for ultrasonic dispersion to form a coating liquid, the mass ratio of sodium lignosulfonate to chitosan is 0.2:1, and the mass ratio of quinoline copper to chitosan is 1:2.

[0045] Step three, drop the homogeneous emulsion into the coating liquid, the mass ratio of homogeneous emulsion to coating liquid is 7:3, constant temperature stirring at 50℃, adjust the pH to 6.5, spray drying to obtain granular bactericide, control the inlet air temperature of spray drying to be 120℃, and the outlet air temperature to be 80℃, the obtained bactericide granule particle size is 5-15μm.

[0046] Example 5

[0047] The difference from example 1 is that the mass concentration of benzalkonium bromide is increased from 10% to 15%, and the mass concentration of tea saponin is increased from 3% to 8%.

[0048] The present embodiment provides a bactericide containing thiophanate-methyl, which includes core material and capsule wall material; the active components in the core material include thiophanate-methyl, quaternary ammonium salt, methenamine and tea saponin; the capsule wall material includes chitosan, sodium lignosulfonate and quinoline copper, and the capsule wall material forms a coating on the core material.

[0049] The preparation steps of the bactericide are as follows: Step one, grinding thiophanate-methyl and methenamine through 200 mesh sieve, adding benzalkonium bromide (quaternary ammonium salt) and tea saponin, stirring and mixing evenly, then adding Tween 80 and water, stirring and mixing at 50-60℃, forming a homogeneous emulsion. Among them, the mass concentration of thiophanate-methyl is 40%, the mass concentration of methenamine is 10%, the mass concentration of benzalkonium bromide is 15%, the mass concentration of tea saponin is 8%, the mass concentration of Tween 80 is 1%, and the rest is water.

[0050] Step two, dissolve chitosan in a 2wt% acetic acid solution to obtain a 2wt% chitosan solution, add sodium lignosulfonate and quinoline copper for ultrasonic dispersion to form a coating liquid, the mass ratio of sodium lignosulfonate to chitosan is 0.2:1, and the mass ratio of quinoline copper to chitosan is 1:2.

[0051] Step three, the homogeneous emulsion is added to the coating liquid, the mass ratio of the homogeneous emulsion and the coating liquid is 7:3, constant temperature stirring at 50℃, adjusting pH to 6.5, spray drying to get granular bactericide, controlling the inlet air temperature of spray drying to be 120℃, the outlet air temperature to be 80℃, the particle size of the obtained bactericide granules is 5-15μm.

[0052] Example 6

[0053] The difference from example 4 is that the mass ratio of sodium lignosulfonate and chitosan is adjusted from 0.2:1 to 0.3:1, and the mass ratio of copper quinolinolate and chitosan is 1.2:2.

[0054] This example provides a bactericide containing thiophanate-methyl, which comprises core material and capsule wall material; the active components in the core material include thiophanate-methyl, quaternary ammonium salt, hexamethylenetetramine and tea saponin; the capsule wall material includes chitosan, sodium lignosulfonate and copper quinolinolate, and the capsule wall material forms a coating on the core material.

[0055] The preparation steps of the bactericide are as follows: Step one, grind thiophanate-methyl and hexamethylenetetramine through a 200-mesh sieve, add benzalkonium bromide (quaternary ammonium salt) and tea saponin, stir and mix uniformly, then add Tween 80 and water, stir and mix at 50-60℃, to form a homogeneous emulsion. Among them, the mass concentration of thiophanate-methyl is 40%, the mass concentration of hexamethylenetetramine is 10%, the mass concentration of benzalkonium bromide is 12%, the mass concentration of tea saponin is 5%, the mass concentration of Tween 80 is 1%, and the rest is water.

[0056] Step two, dissolve chitosan in a 2wt% acetic acid solution to obtain a 2wt% chitosan solution, add sodium lignosulfonate and copper quinolinolate and ultrasonic dispersion to form a coating liquid, the mass ratio of sodium lignosulfonate and chitosan is 0.3:1, and the mass ratio of copper quinolinolate and chitosan is 1.2:2.

[0057] Step three, the homogeneous emulsion is added to the coating liquid, the mass ratio of the homogeneous emulsion and the coating liquid is 7:3, constant temperature stirring at 50℃, adjusting pH to 6.5, spray drying to get granular bactericide, controlling the inlet air temperature of spray drying to be 120℃, the outlet air temperature to be 80℃, the particle size of the obtained bactericide granules is 5-15μm.

[0058] Example 7

[0059] The difference from example 1 is that the mass ratio of sodium lignosulfonate and chitosan is adjusted from 0.2:1 to 0.4:1, and the mass ratio of copper quinolinolate and chitosan is 1.3:2.

[0060] The embodiment provides a bactericide containing thiophanate-methyl, which comprises core material and capsule wall material; active components in the core material comprise thiophanate-methyl, quaternary ammonium salt, hexamethylenetetramine and tea saponin; the capsule wall material comprises chitosan, sodium lignosulfonate and quinoline copper, and the capsule wall material forms a coating on the core material.

[0061] The preparation steps of the bactericide are as follows: Step one, grind thiophanate-methyl and hexamethylenetetramine through a 200-mesh screen, add benzalkonium bromide (quaternary ammonium salt) and tea saponin, stir and mix uniformly, then add Tween 80 and water, and stir and mix at 50-60 DEG C to form a homogeneous emulsion; wherein the mass concentration of thiophanate-methyl is 40%, the mass concentration of hexamethylenetetramine is 10%, the mass concentration of benzalkonium bromide is 12%, the mass concentration of tea saponin is 5%, the mass concentration of Tween 80 is 1%, and the rest is water.

[0062] Step two, dissolve chitosan in an acetic acid solution with a mass concentration of 2wt% to obtain a chitosan solution with a concentration of 2wt%, then add sodium lignosulfonate and quinoline copper and ultrasonically disperse to form a coating liquid, the mass ratio of sodium lignosulfonate to chitosan is 0.4:1, and the mass ratio of quinoline copper to chitosan is 1.3:2.

[0063] Step three, drop the homogeneous emulsion into the coating liquid, the mass ratio of the homogeneous emulsion to the coating liquid is 7:3, constant-temperature stir at 50 DEG C, adjust the pH to 6.5, and spray dry to obtain a granular bactericide, the inlet air temperature of the spray drying is controlled to be 120 DEG C, and the outlet air temperature is controlled to be 80 DEG C, and the obtained bactericide granules have a particle size of 5-15 mu m.

[0064] Comparative example 1

[0065] The difference between the embodiment and the comparative example is that tea saponin is not added to the core material in the comparative example.

[0066] The embodiment provides a bactericide containing thiophanate-methyl, which comprises core material and capsule wall material; active components in the core material comprise thiophanate-methyl, quaternary ammonium salt and hexamethylenetetramine; and the capsule wall material comprises chitosan, sodium lignosulfonate and quinoline copper, and the capsule wall material forms a coating on the core material.

[0067] The preparation steps of the bactericide are as follows: Step one, grind thiophanate-methyl and hexamethylenetetramine through a 200-mesh screen, add benzalkonium bromide (quaternary ammonium salt), stir and mix uniformly, then add Tween 80 and water, and stir and mix at 50-60 DEG C to form a homogeneous emulsion; wherein the mass concentration of thiophanate-methyl is 40%, the mass concentration of hexamethylenetetramine is 10%, the mass concentration of benzalkonium bromide is 10%, the mass concentration of Tween 80 is 1%, and the rest is water.

[0068] Step 2: Dissolve chitosan in a 2wt% acetic acid solution to obtain a 2wt% chitosan solution. Add sodium lignosulfonate and quinoline copper and disperse ultrasonically to form a coating solution. The mass ratio of sodium lignosulfonate to chitosan is 0.2:1, and the mass ratio of quinoline copper to chitosan is 1:2.

[0069] Step 3: Add the homogenized emulsion dropwise to the coating solution at a mass ratio of 7:3. Stir at a constant temperature of 50℃, adjust the pH to 6.5, and spray dry to obtain granular bactericide. Control the inlet air temperature of the spray dryer to 120℃ and the outlet air temperature to 80℃. The resulting bactericide particles have a particle size of 5-15μm.

[0070] Comparative Example 2

[0071] The difference from Example 1 is that benzalkonium bromide is not added to the core material in this comparative example.

[0072] This embodiment provides a fungicide containing thiophanate-methyl, the fungicide comprising a core material and a capsule wall material; the active components in the core material include thiophanate-methyl, hexamethylenetetramine, and tea saponin; the capsule wall material includes chitosan, sodium lignin sulfonate, and quinoline copper, and the capsule wall material coats the core material.

[0073] The preparation steps of the bactericide are as follows: Step 1: Grind thiophanate-methyl and hexamethylenetetramine through a 200-mesh sieve, add tea saponin, stir and mix evenly, then add Tween 80 and water, and stir and mix at 50-60℃ to form a homogeneous emulsion. The mass concentrations of thiophanate-methyl are 40%, hexamethylenetetramine 10%, tea saponin 5%, Tween 80 1%, and the remainder is water.

[0074] Step 2: Dissolve chitosan in a 2wt% acetic acid solution to obtain a 2wt% chitosan solution. Add sodium lignosulfonate and quinoline copper and disperse ultrasonically to form a coating solution. The mass ratio of sodium lignosulfonate to chitosan is 0.3:1, and the mass ratio of quinoline copper to chitosan is 1.2:2.

[0075] Step 3: Add the homogenized emulsion dropwise to the coating solution at a mass ratio of 7:3. Stir at a constant temperature of 50℃, adjust the pH to 6.5, and spray dry to obtain granular bactericide. Control the inlet air temperature of the spray dryer to 120℃ and the outlet air temperature to 80℃. The resulting bactericide particles have a particle size of 5-15μm.

[0076] Comparative Example 3

[0077] The difference from Example 1 is that sodium lignosulfonate is not added to the capsule wall material in this comparative example.

[0078] The present embodiment provides a bactericide containing thiophanate-methyl, which comprises core material and capsule wall material; the active components in the core material comprise thiophanate-methyl, quaternary ammonium salt, hexamethylenetetramine and tea saponin; the capsule wall material comprises chitosan and quinoline copper, and the capsule wall material forms a coating on the core material.

[0079] The preparation steps of the bactericide are as follows: Step one, grind thiophanate-methyl and hexamethylenetetramine through a 200-mesh sieve, add benzalkonium bromide (quaternary ammonium salt) and tea saponin, stir and mix uniformly, then add Tween 80 and water, stir and mix at 50-60°C to form a homogeneous emulsion. Among them, the mass concentration of thiophanate-methyl is 40%, the mass concentration of hexamethylenetetramine is 10%, the mass concentration of benzalkonium bromide is 10%, the mass concentration of tea saponin is 3%, the mass concentration of Tween 80 is 1%, and the rest is water.

[0080] Step two, dissolve chitosan in a 2wt% acetic acid solution to obtain a 2wt% chitosan solution, and then add quinoline copper and ultrasonically disperse to form a coating liquid. The mass ratio of quinoline copper to chitosan is 1:2.

[0081] Step three, drop the homogeneous emulsion into the coating liquid, the mass ratio of the homogeneous emulsion to the coating liquid is 7:3, stir at 50°C, adjust the pH to 6.5, and spray dry to obtain a granular bactericide. The inlet air temperature of the spray drying is controlled at 120°C, and the outlet air temperature is controlled at 80°C. The particle size of the obtained bactericide granules is 5-15μm.

[0082] Comparative Example 4

[0083] The difference between this comparative example and Example 1 is that no quinoline copper is added to the capsule wall material in this comparative example.

[0084] The present embodiment provides a bactericide containing thiophanate-methyl, which comprises core material and capsule wall material; the active components in the core material comprise thiophanate-methyl, quaternary ammonium salt, hexamethylenetetramine and tea saponin; the capsule wall material comprises chitosan and sodium lignosulfonate, and the capsule wall material forms a coating on the core material.

[0085] The preparation steps of the bactericide are as follows: Step one, grind thiophanate-methyl and hexamethylenetetramine through a 200-mesh sieve, add benzalkonium bromide (quaternary ammonium salt) and tea saponin, stir and mix uniformly, then add Tween 80 and water, stir and mix at 50-60°C to form a homogeneous emulsion. Among them, the mass concentration of thiophanate-methyl is 40%, the mass concentration of hexamethylenetetramine is 10%, the mass concentration of benzalkonium bromide is 10%, the mass concentration of tea saponin is 3%, the mass concentration of Tween 80 is 1%, and the rest is water.

[0086] Step two, dissolve chitosan in acetic acid solution with a mass concentration of 2wt%, obtain chitosan solution with a concentration of 2wt%, add sodium lignosulfonate and ultrasonic dispersion, form a coating liquid, the mass ratio of sodium lignosulfonate and chitosan is 0.2:1.

[0087] Step three, add the homogeneous emulsion to the coating liquid, the mass ratio of the homogeneous emulsion and the coating liquid is 7:3, constant temperature stirring at 50℃, adjust the pH to 6.5, spray drying to obtain granular bactericide, control the inlet air temperature of spray drying to 120℃, the outlet air temperature to 80℃, the particle size of the obtained bactericide is 5-15μm.

[0088] Field efficacy test of bactericides prepared in example 1 to example 7 and comparative example 1 to comparative example 4, select the field with serious disease of wheat powdery mildew as test field, divide into 12 blocks with equal area, each block area is 50 square meters, add bactericide into water with 1000 times liquid to form dispersed pesticide by stirring, uniform spray at early stage of disease, wheat leaves are covered with pesticide, one block is not treated with pesticide as blank area, the remaining 11 blocks are treated with bactericides of examples and comparative examples, investigate the disease condition of leaves before treatment, third day after spraying and seventh day after spraying, the amount of pesticide is 0.1g / m 2 , calculate the control effect, the results are shown in table 1.

[0089] Leaf disease classification standard: 0 level: no disease spot; 1 level: disease spot area accounts for less than 5% of the whole leaf area; 3 level: disease spot area accounts for 6%-15% of the whole leaf area; 5 level: disease spot area accounts for 16%-25% of the whole leaf area; 7 level: disease spot area accounts for 26%-50% of the whole leaf area; 9 level: disease spot area accounts for more than 50% of the whole leaf area.

[0090] Efficacy calculation method: , .

[0091] Table 1

[0092] As shown in Table 1, the fungicide provided in this invention exhibits a slow-release effect during field trials, gradually releasing its active components after application to kill bacteria. The control effect significantly improves after 7 days of follow-up application. Comparative examples show that in Comparative Examples 1 and 2, the lack of either quaternary ammonium salt or tea saponin weakens the damaging effect on the outer cell membrane or cell wall of pathogens, making it difficult for the active components in the core to enter the cell, thus reducing the control effect. Pathogens in perennially diseased fields often exhibit strong resistance, but the fungicide provided by this invention weakens resistance and enhances efficacy, achieving long-term inhibition of pathogen growth through slow release, resulting in significant control effects.

[0093] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0094] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A fungicide containing thiophanate-methyl, characterized in that, The bactericide comprises a core material and a capsule wall material; the active components in the core material include thiophanate-methyl, quaternary ammonium salt, hexamethylenetetramine, and tea saponin; the capsule wall material includes chitosan, sodium lignin sulfonate, and quinoline copper, and the capsule wall material coats the core material.

2. The fungicide containing methyl thiophanate according to claim 1, characterized in that, The preparation steps of the bactericide are as follows: S1. Grind thiophanate-methyl and hexamethylenetetramine through a 200-mesh sieve, add quaternary ammonium salt and tea saponin, stir and mix evenly, then add Tween 80 and water, stir and mix at 50-60℃ to form a homogeneous emulsion. S2. Dissolve chitosan in acetic acid solution to obtain chitosan solution, add sodium lignosulfonate and quinoline copper and disperse by ultrasonication to form coating solution; S3. Add the homogenized emulsion dropwise to the coating solution, stir at a constant temperature of 40-50℃, adjust the pH to 6.0-6.5, and spray dry to obtain granular bactericide.

3. The fungicide containing methyl thiophanate according to claim 2, characterized in that, The mass concentration of thiophanate-methyl in the homogenized emulsion is 40-50%.

4. The fungicide containing thiophanate-methyl according to claim 2, characterized in that, The mass concentration of hexamethylenetetramine in the homogeneous emulsion is 8-12%.

5. A fungicide containing methyl thiophanate according to claim 2, characterized in that, The quaternary ammonium salt is at least one of decyl dimethyl ammonium chloride, benzalkonium bromide and benzalkonium chloride; The mass concentration of quaternary ammonium salt in the homogeneous emulsion is 10-15%; The mass concentration of tea saponin in the homogenized emulsion is 3-8%.

6. The fungicide containing methyl thiophanate according to claim 2, characterized in that, The mass concentration of Tween 80 in the homogenized emulsion is 1-3%.

7. A fungicide containing thiophanate-methyl according to claim 2, characterized in that, The acetic acid solution has a mass concentration of 1-3 wt%. The chitosan solution contains 1-2 wt% chitosan.

8. A fungicide containing thiophanate-methyl according to claim 2, characterized in that, The mass ratio of sodium lignosulfonate to chitosan is 0.2-0.4:1; The mass ratio of quinoline copper to chitosan is 1-1.3:

2.

9. A fungicide containing thiophanate-methyl according to claim 2, characterized in that, The mass ratio of the homogenized emulsion to the coating solution is (6-8):(2-4).

10. A fungicide containing thiophanate-methyl according to claim 1, characterized in that, The particle size of the bactericide is 5-15 μm.

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