阅读说明：本技术 一种二甲基二硫微囊悬浮剂及其制备方法和应用 (Dimethyl disulfide microcapsule suspending agent and preparation method and application thereof ) 是由 任立瑞 曹坳程 王秋霞 李园 欧阳灿彬 颜冬冬 郭美霞 于 2019-10-25 设计创作，主要内容包括：本发明涉及农药制剂技术领域,提供了一种二甲基二硫微囊悬浮剂及其制备方法和应用。所述二甲基二硫微囊包括囊壳和被包裹在囊壳内的二甲基二硫,所述囊壳由囊材单体与交联剂接触后,在油水界面发生聚合反应形成。本发明无需加入甲醛,对环境安全,所得微囊悬浮剂耐储存、方便运输和使用；二甲基二硫被包裹于囊壳之内,起到缓释增效的作用,施药量少,药效好,且生产成本低,环境污染小,可以有效杀灭线虫、土传病原真菌及地下害虫,还可以有效去除杂草。(The invention relates to the technical field of pesticide preparations, and provides a dimethyl disulfide microcapsule suspending agent as well as a preparation method and application thereof. The dimethyl disulfide microcapsule comprises a capsule shell and dimethyl disulfide wrapped in the capsule shell, wherein the capsule shell is formed by the polymerization reaction of a capsule material monomer and a cross-linking agent at an oil-water interface. The invention does not need to add formaldehyde, is safe to the environment, and the obtained microcapsule suspending agent is storage-resistant and convenient to transport and use; the dimethyl disulfide is wrapped in the capsule shell, has the effects of slow release and synergy, has small application amount, good drug effect, low production cost and small environmental pollution, can effectively kill nematodes, soil-borne pathogenic fungi and underground pests, and can also effectively remove weeds.)

1. The dimethyl disulfide microcapsule suspension is characterized in that the dimethyl disulfide microcapsule comprises a capsule shell and dimethyl disulfide wrapped in the capsule shell, and the capsule shell is formed by the polymerization reaction of a capsule material monomer and a cross-linking agent at an oil-water interface; the dimethyl disulfide microcapsule suspending agent is prepared from the following components in percentage by mass: 1 to 30 percent of dimethyl disulfide, 0.3 to 15 percent of capsule material monomer, 0.1 to 10 percent of cross-linking agent, 5 to 30 percent of oil phase solvent, 1 to 10 percent of protective rubber, 0.2 to 10 percent of surfactant, 0.1 to 0.5 percent of defoaming agent, 0.1 to 1 percent of viscosity regulator, 1 to 4 percent of antifreeze agent, 0.1 to 1 percent of preservative and 30 to 80 percent of water.

2. The dimethyl disulfide microcapsule suspension according to claim 1 wherein the shell comprises one or more of polyurea, polyurethane, polyamide, polycarbonate, and polysulfonamide.

3. The dimethyl disulfide microcapsule suspension according to claim 1, wherein the capsule wall material monomer comprises one or more of polyisocyanate, polyacid chloride, polychloroformate and polysulfonyl chloride.

4. The dimethyl disulfide microcapsule suspension according to claim 1, wherein said cross-linking agent comprises one or more of a polyol or a polyamine; the polyhydric alcohol comprises ethylene glycol and/or 1, 4-butanediol; the polyamine comprises one or more of ethylenediamine, 1, 3-propanediamine, 1, 4-butanediamine, 1, 5-pentanediamine, 1, 6-hexanediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine.

5. The dimethyl disulfide microcapsule suspension according to claim 3, wherein said polyisocyanate comprises one or more of tetramethylene xylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, xylene diisocyanate, polymethylene polyphenylene polyisocyanate, 2,4,4' -diphenyl ether triisocyanate, 3' -dimethyl-4, 4' -diphenyl diisocyanate, 3' -dimethoxy-4, 4' -diphenyl diisocyanate, 1, 5-naphthylene diisocyanate and isophorone diisocyanate.

6. The dimethyl disulfide microcapsule suspension according to claim 1, wherein said oil phase solvent comprises one or more of xylene, mineral spirits, methyl oleate, and methyl esterified soybean oil; the protective gum comprises one or more of gum arabic, gelatin, chitosan, polyvinyl alcohol, starch, sodium alginate, calcium alginate, agar, agarose, protein substances and fat substances.

7. The dimethyl disulfide microcapsule suspension according to claim 1, wherein said surfactant comprises one or more of polycarboxylate, alkylphenol polyoxyethylene ether formaldehyde condensate sulfate, alkyl naphthalene sulfonate, alkylbenzene sulfonate, lignosulfonate, polyoxyethylene ether phosphate, styrylphenol polyoxyethylene ether phosphate, fatty alcohol polyoxyethylene ether, polyoxyethylene polyoxypropylene block copolymer, vegetable oil ethylene oxide adduct and derivatives, styrene maleic anhydride copolymer, polyvinyl alcohol and acrylic acid copolymer; the defoaming agent comprises a polyether defoaming agent and/or an organic silicon defoaming agent; the viscosity regulator comprises one or more of xanthan gum, starch and magnesium aluminum silicate; the antifreeze comprises one or more of glycerol, glycol and urea; the preservative is cason and/or sodium benzoate.

8. A process for the preparation of a suspension of dimethyl disulphide microcapsules according to any one of claims 1 to 7, comprising the following steps:

mixing dimethyl disulfide, a capsule wall material monomer and an oil phase solvent to obtain an oil phase;

mixing the protective adhesive, the surfactant, the defoaming agent and water to obtain a water phase;

adding the oil phase into the water phase for shearing and emulsifying to obtain emulsion;

and heating the emulsion to 30-60 ℃, adding a cross-linking agent to enable a capsule wall material monomer to be in contact with the cross-linking agent, carrying out a polymerization reaction on an oil-water interface, adding a viscosity regulator, an anti-freezing agent and a preservative after the reaction is carried out for 1-3 h, and then continuing the reaction for 0.5-1 h to obtain the dimethyl disulfide microcapsule suspending agent.

9. Use of a dimethyl disulfide microcapsule suspension as claimed in any one of claims 1 to 7 for controlling plant diseases and pests and for weeding.

10. The use according to claim 9, wherein the dimethyl disulfide microcapsule suspension is administered in an amount of 20-149.9 kg a.i./ha.

Technical Field

The invention relates to the technical field of pesticide preparations, and particularly relates to a dimethyl disulfide microcapsule suspending agent as well as a preparation method and application thereof.

Background

Soil-borne diseases are a class of plant diseases caused by infection with pathogens that survive in the soil. The plant cultivation method is serious in vegetables, melons and fruits and ornamental plants, and particularly serious in damage to crops in a greenhouse. Generally, after 3-5 years of greenhouse cultivation, the yield and quality of crops are seriously affected, and the yield is generally reduced by 20-40%, and the serious yield is reduced by more than 60% or even no harvest is caused.

The most common and effective method for controlling soil-borne diseases is soil fumigation, and most of fumigants used are methyl bromide. The methyl bromide is used for soil disinfection, so that nematodes, fungi, pests, weeds and the like in soil can be well eliminated, the crop yield is remarkably increased, and the methyl bromide is deeply welcomed by farmers and widely applied at home and abroad. However, methyl bromide is regarded as a limiting substance by the environmental program agency of the United nations and is prohibited from being used in 2015 because methyl bromide destroys ozone layer substances. Dimethyl disulfide is a potential methyl bromide substitute and has been registered for use on crops such as tomatoes, peppers, cucumbers and the like in the united states, canada, australia. The dimethyl disulfide has good prevention and control effects on nematodes in soil and certain prevention and control effects on soil-borne diseases. Dimethyl disulfide is usually injected by a stock solution or prepared into missible oil for drip irrigation application, but because the medicament is extremely volatile, the application amount needs to be increased for achieving the ideal medicament effect, so that the environment is polluted, and the body health of the personnel applying the medicament is threatened.

Chinese patent CN 101491242 discloses an application technology for directly using dimethyl disulfide in the field by processing into capsules, wherein the coating material of the capsules is selected from one or more of melamine formaldehyde resin, urea formaldehyde resin, gelatin and acacia, wherein the melamine formaldehyde resin and the urea formaldehyde resin both need formaldehyde as a cross-linking phase, and if the reaction is incomplete, the formaldehyde can remain in the product, which can cause serious influence on the environment; the gelatin is easy to melt when heated, and the Arabic gum is very soluble in water, so that the capsule prepared by the gelatin and the Arabic gum serving as the capsule shells is difficult to store, transport and use. Chinese patent CN104604860 discloses a method for preparing granules from dimethyl disulfide by using zeolite as a carrier. Because the pore diameter of the zeolite is larger, the dimethyl disulfide is easy to volatilize and dissipate from the zeolite, so that the ideal slow release effect cannot be achieved. Chinese patent CN1507321 discloses that at least one sulfur compound of dimethyl disulfide is applied in the form of stock solution, aqueous emulsion, microemulsion, microcapsule or solid as carrier in the soil or plant substrate, but the application amount is high, 150-1000 kg a.i./ha.

Disclosure of Invention

In view of the above, the present invention aims to provide a dimethyl disulfide microcapsule suspending agent, a preparation method and applications thereof. The dimethyl disulfide microcapsule suspending agent provided by the invention does not need to use formaldehyde, is environment-friendly, has the advantages of difficult damage of capsule shells, storage resistance and convenience in transportation and use, can achieve a good slow release effect, can greatly reduce the dosage of the medicament under the condition of ensuring an ideal medicament effect, and prolongs the duration.

In order to achieve the above object, the present invention provides the following technical solutions:

a dimethyl disulfide microcapsule suspension, wherein the dimethyl disulfide microcapsule comprises a capsule shell and dimethyl disulfide encapsulated in the capsule shell, and the capsule shell is formed by polymerization reaction at an oil-water interface after a capsule wall material monomer contacts a cross-linking agent; the dimethyl disulfide microcapsule suspending agent is prepared from the following components in percentage by mass: 1 to 30 percent of dimethyl disulfide, 0.3 to 15 percent of capsule material monomer, 0.1 to 10 percent of cross-linking agent, 5 to 30 percent of oil phase solvent, 1 to 10 percent of protective rubber, 0.2 to 10 percent of surfactant, 0.1 to 0.5 percent of defoaming agent, 0.1 to 1 percent of viscosity regulator, 1 to 4 percent of antifreeze agent, 0.1 to 1 percent of preservative and 30 to 80 percent of water.

The capsule shell comprises one or more of polyurea, polyurethane, polyamide, polycarbonate and polysulfonamide.

The capsule wall material monomer comprises one or more of polyisocyanate, polyacid chloride, polychloroformate and polysulfonyl chloride.

The polyisocyanate comprises one or more of tetramethylene xylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, xylene diisocyanate, polymethylene polyphenylene polyisocyanate, 2,4,4' -diphenyl ether triisocyanate, 3' -dimethyl-4, 4' -diphenyl diisocyanate, 3' -dimethoxy-4, 4' -diphenyl diisocyanate, 1, 5-naphthylene diisocyanate and isophorone diisocyanate.

The cross-linking agent comprises one or more of polyalcohol or polyamine.

The polyhydric alcohol comprises ethylene glycol and/or 1, 4-butanediol; the polyamine comprises one or more of ethylenediamine, 1, 3-propanediamine, 1, 4-butanediamine, 1, 5-pentanediamine, 1, 6-hexanediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine.

The oil phase solvent comprises one or more of dimethylbenzene, solvent oil, methyl oleate and methyl esterified soybean oil.

The protective gum comprises one or more of gum arabic, gelatin, chitosan, polyvinyl alcohol, starch, sodium alginate, calcium alginate, agar, agarose, protein substances and fat substances.

The surfactant comprises one or more of polycarboxylate, alkylphenol polyoxyethylene ether formaldehyde condensate sulfate, alkyl naphthalene sulfonate, alkylbenzene sulfonate, lignosulfonate, polyoxyethylene ether phosphate, styryl phenol polyoxyethylene ether phosphate, fatty alcohol polyoxyethylene ether, polyoxyethylene polyoxypropylene block copolymer, vegetable oil epoxy ethane addition compound and derivative, styrene maleic anhydride copolymer, polyvinyl alcohol and acrylic acid copolymer.

The defoaming agent comprises a polyether defoaming agent and/or an organic silicon defoaming agent; the viscosity regulator comprises one or more of xanthan gum, starch and magnesium aluminum silicate; the antifreeze comprises one or more of glycerol, glycol and urea; the preservative is cason and/or sodium benzoate.

The invention provides a preparation method of the dimethyl disulfide microcapsule suspending agent in the scheme, which comprises the following steps:

mixing dimethyl disulfide, a capsule wall material monomer and an oil phase solvent to obtain an oil phase;

mixing the protective adhesive, the surfactant, the defoaming agent and water to obtain a water phase;

adding the oil phase into the water phase for shearing and emulsifying to obtain emulsion;

heating the emulsion to 30-60 ℃, adding a cross-linking agent, allowing a capsule material monomer to contact with the cross-linking agent and then to perform a polymerization reaction on an oil-water interface, adding a viscosity regulator, an anti-freezing agent and a preservative after the reaction is performed for 1-3 hours, and then continuing the reaction for 0.5-1 hour to obtain the dimethyl disulfide microcapsule suspending agent.

The invention provides application of the dimethyl disulfide microcapsule suspending agent in the scheme in prevention and treatment of plant diseases and insect pests and weeding.

The application dosage of the dimethyl disulfide microcapsule suspending agent is 20-149.9 kg a.i./ha.

The invention provides a dimethyl disulfide microcapsule suspending agent, which comprises a capsule shell and dimethyl disulfide wrapped in the capsule shell, wherein the capsule shell is formed by polymerization reaction of a capsule material monomer and a cross-linking agent at an oil-water interface. The microcapsule suspending agent is storage-resistant, convenient to transport and use and safe to the environment; the dimethyl disulfide is wrapped in the capsule shell, has the functions of slow release and synergy, and has the advantages of low application amount, reduced production cost, reduced environmental pollution and ensured safety of application personnel.

The invention provides a preparation method of the dimethyl disulfide microcapsule suspending agent in the scheme, and the preparation method provided by the invention is easy to operate, low in cost and suitable for large-scale production.

The invention also provides application of the dimethyl disulfide microcapsule suspending agent in the scheme in prevention and treatment of plant diseases and insect pests and weeding. The dimethyl disulfide microcapsule suspending agent provided by the invention can be used in any growth period of plants, and is safe to the plants. The results of the examples show that the dimethyl disulfide microcapsule suspension provided by the invention can be applied in the seedling stage, the adult stage and the fruiting stage of plants, no phytotoxicity is caused, the average control effect of 90d after the application can reach 72.5% under the condition that the application amount is 37.25kg a.i./ha, and the average control effect of 90d after the application is only 45.3% under the condition that the application amount is 600kg a.i./ha.

Detailed Description

The invention provides a dimethyl disulfide microcapsule suspending agent, which comprises a capsule shell and dimethyl disulfide wrapped in the capsule shell, wherein the capsule shell is formed by the polymerization reaction of a capsule material monomer and a cross-linking agent at an oil-water interface after the contact.

In the invention, the dimethyl disulfide microcapsule suspending agent is prepared from the following components in percentage by mass: 1 to 30 percent of dimethyl disulfide, 0.3 to 15 percent of capsule material monomer, 0.1 to 10 percent of cross-linking agent, 5 to 30 percent of oil phase solvent, 1 to 10 percent of protective rubber, 0.2 to 10 percent of surfactant, 0.1 to 0.5 percent of defoaming agent, 0.1 to 1 percent of viscosity regulator, 1 to 4 percent of antifreeze agent, 0.1 to 1 percent of preservative and 30 to 80 percent of water.

The dimethyl disulfide microcapsule suspension of the present invention is prepared from commercially available raw materials, unless otherwise specified.

The dimethyl disulfide microcapsule suspending agent provided by the invention comprises 1-30% of dimethyl disulfide, preferably 5-25% of dimethyl disulfide and more preferably 10-20% of dimethyl disulfide; in the present invention, the dimethyl disulfide is an active ingredient of the microcapsule suspension of the present invention.

The raw materials for preparing the dimethyl disulfide microcapsule suspending agent comprise, by mass, 0.3-15% of capsule wall material monomers, preferably 0.5-12%, and more preferably 1-10%. In the invention, the capsule shell preferably comprises one or more of polyurea, polyurethane, polyamide, polycarbonate and polysulfonamide, and is more preferably polyurea; the capsule wall material monomer comprises polyisocyanate, polyacid chloride, polychloroformate and polysulfonyl chloride, preferably polyisocyanate; the polyisocyanate preferably includes one or more of tetramethylene xylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, xylene diisocyanate, polymethylene polyphenylene polyisocyanate, 2,4,4' -diphenyl ether triisocyanate, 3' -dimethyl-4, 4' -diphenyl diisocyanate, 3' -dimethoxy-4, 4' -diphenyl diisocyanate, 1, 5-naphthylene diisocyanate and isophorone diisocyanate, and more preferably isophorone diisocyanate. In the invention, the capsule shell is formed by polymerizing the capsule shell monomer at an oil-water interface after the capsule shell monomer contacts with the cross-linking agent.

The raw materials for preparing the dimethyl disulfide microcapsule suspending agent comprise, by mass, 0.1-10% of a cross-linking agent, preferably 1-10%, and more preferably 1-5%. In the present invention, the cross-linking agent comprises a polyhydric alcohol or a polyhydric amine, preferably comprises one or more of ethylenediamine, 1, 3-propanediamine, 1, 4-butanediamine, 1, 5-pentanediamine, 1, 6-hexanediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, ethylene glycol, and 1, 4-butanediol, and more preferably comprises ethylenediamine.

The raw materials for preparing the dimethyl disulfide microcapsule suspending agent comprise 5-30% of oil phase solvent, preferably 8-25%, and more preferably 10-20% by mass. In the present invention, the oil phase solvent preferably comprises one or more of xylene, mineral spirit, methyl oleate and methyl esterified soybean oil, and more preferably 200# mineral spirit.

The dimethyl disulfide microcapsule suspending agent provided by the invention comprises 1-10% of protective rubber, and more preferably 5-10% of raw materials. In the invention, the protective gum preferably comprises one or more of gum arabic, gelatin, chitosan, polyvinyl alcohol, starch, sodium alginate, calcium alginate, agar, agarose, protein substances and fat substances, and more preferably gelatin; in the invention, the protective gel is used for maintaining the stability of the system emulsion, preventing oil drops from coalescing and facilitating the polymerization reaction of the capsule wall material monomer and the cross-linking agent in contact with an oil-water interface without causing the precipitation of an oil phase.

The dimethyl disulfide microcapsule suspending agent provided by the invention comprises 0.2-10% of surfactant, preferably 0.5-8%, and more preferably 1-5% of raw materials by mass. In the present invention, the surfactant preferably includes one or more of a polycarboxylate, an alkylphenol polyoxyethylene ether formaldehyde condensate sulfate, an alkylnaphthalene sulfonate, an alkylbenzene sulfonate, a lignosulfonate, a polyoxyethylene ether phosphate, a styrylphenol polyoxyethylene ether phosphate, a fatty alcohol polyoxyethylene ether, a polyoxyethylene polyoxypropylene block copolymer, a vegetable oil ethylene oxide adduct and derivative, a styrene maleic anhydride copolymer, a polyvinyl alcohol, and an acrylic acid copolymer, and more preferably a lignosulfonate.

The raw materials for preparing the dimethyl disulfide microcapsule suspending agent comprise 0.1-0.5% of defoaming agent, and preferably 0.1-0.3% by mass. In the present invention, the defoaming agent preferably includes a polyether defoaming agent and/or a silicone defoaming agent, and more preferably a silicone defoaming agent.

The raw materials for preparing the dimethyl disulfide microcapsule suspending agent comprise 0.1-1% of viscosity regulator, preferably 0.5-1% by mass. In the invention, the viscosity regulator comprises one or more of xanthan gum, starch and magnesium aluminum silicate, and xanthan gum is more preferable.

The dimethyl disulfide microcapsule suspending agent provided by the invention comprises 1-4% of antifreeze agent, preferably 1-3% of raw material. In the present invention, the antifreeze agent preferably includes one or more of glycerol, ethylene glycol and urea, and more preferably glycerol.

The raw materials for preparing the dimethyl disulfide microcapsule suspending agent comprise 0.1-1% of preservative, preferably 0.1-0.5% by mass. In the present invention, the preservative is preferably cason and/or sodium benzoate, more preferably cason.

The preparation raw material of the dimethyl disulfide microcapsule suspending agent comprises, by mass, 30-80% of water, and preferably 35-75%. In the present invention, the water is preferably deionized water.

The invention provides a preparation method of the dimethyl disulfide microcapsule suspending agent in the scheme, which comprises the following steps:

mixing dimethyl disulfide, a capsule wall material monomer and an oil phase solvent to obtain an oil phase;

mixing the protective adhesive, the surfactant, the defoaming agent and water to obtain a water phase;

adding the oil phase into the water phase for shearing and emulsifying to obtain emulsion;

heating the emulsion to 30-60 ℃, adding a cross-linking agent, allowing a capsule wall material monomer to contact with the cross-linking agent and then perform a polymerization reaction on an oil-water interface, adding a viscosity regulator, an anti-freezing agent and a preservative after the reaction is performed for 1-3 hours, and then continuing the reaction for 0.5-1 hour to obtain the dimethyl disulfide microcapsule suspending agent.

The invention has no special requirements on the mixing mode when preparing the oil phase and the water phase, and can ensure that all raw materials are uniformly mixed and fully dissolved.

After the oil phase and the water phase are obtained, the oil phase is added into the water phase for shearing and emulsification to obtain emulsion. In the invention, the rotation speed of the shearing emulsification is preferably 2000-12000 rpm, more preferably 3000-11000 rpm; the oil phase is preferably slowly dripped into the water phase under the high-speed shearing condition of 2000-12000 rpm, and the emulsion can be obtained by continuously shearing for 1min after dripping.

After an emulsion is obtained, the emulsion is heated to 30-60 ℃, a cross-linking agent is added, a capsule material monomer is contacted with the cross-linking agent, a polymerization reaction is carried out on an oil-water interface, a viscosity regulator, an anti-freezing agent and a preservative are added after the reaction is carried out for 1-3 hours, and then the reaction is continued for 0.5-1 hour, so that the dimethyl disulfide microcapsule suspending agent is obtained. In the invention, the heating mode is preferably water bath heating; in the heating process, the capsule material monomer contacts with a cross-linking agent to generate a polymerization reaction at an oil-water interface to form a capsule shell; the reaction is carried out for 1-3 h, and the viscosity regulator, the anti-freezing agent and the preservative are added and then the reaction is continued for 0.5-1 h, so that the reaction is more sufficient.

The invention provides application of the dimethyl disulfide microcapsule suspending agent in the scheme in prevention and treatment of plant diseases and insect pests and weeding. The dimethyl disulfide microcapsule suspending agent provided by the invention can be particularly applied to crops such as vegetables, fruits (such as strawberries, grapes and the like), flowers and Chinese herbal medicines, can effectively kill nematodes, soil-borne pathogenic fungi and soil insects, and can also effectively remove weeds; in the invention, the application amount of the dimethyl disulfide microcapsule suspending agent is preferably 20-149.9 kg a.i./ha, more preferably 30-140 kg a.i./ha, and further preferably 50-100 kg a.i./ha; in a specific embodiment of the invention, the application is preferably carried out in the field by a dropper or root irrigation, and the dimethyl disulfide microcapsule suspension is used in any growth period of plants and does not cause phytotoxicity to the plants.

The embodiments of the present invention will be described in detail with reference to the following examples, but they should not be construed as limiting the scope of the present invention.