CN112244028A

CN112244028A - A kind of high-adhesion pesticide microcapsule and preparation method thereof

Info

Publication number: CN112244028A
Application number: CN202011058427.9A
Authority: CN
Inventors: 左明明; 沙建鹏; 李贵豪; 刘延东; 周雨凤; 张耕豪; 杨毓瑾
Original assignee: Changshu Institute of Technology
Current assignee: Changshu Institute of Technology
Priority date: 2020-09-30
Filing date: 2020-09-30
Publication date: 2021-01-22

Abstract

The invention discloses a high-adhesion pesticide microcapsule, which comprises difenoconazole, a dispersant, water, a shell film material, a photoinitiator and a solvent. The dispersant comprises an alkylphenol polyoxyethylene ether sulfosuccinate, nonylphenol polyoxyethylene ether NP-10 and styrene phenol formaldehyde resin polyoxyethylene polyoxypropylene ether; the shell film materials include polyester acrylate, trimethylolpropane triacrylate, Tripropylene glycol diacrylate and dopamine hydrochloride; the photoinitiator includes (2,4,6-trimethylbenzoyl)diphenylphosphine oxide; the solvent includes dipropylene glycol dimethyl ether. The microcapsule shell film of the invention has high encapsulation rate, good formability, high stability and high adhesion performance, and can perfectly encapsulate the pesticide difenoconazole. The preparation method of the microcapsule adopts a novel ultraviolet curing technology, and the process is simple and efficient. , High product conversion rate, energy saving and environmental protection, low cost.

Description

High-adhesiveness pesticide microcapsule and preparation method thereof

Technical Field

The invention relates to a microcapsule and a preparation method thereof, in particular to a high-adhesiveness pesticide microcapsule and a preparation method thereof.

Background

Difenoconazole, also called difenoconazole, belongs to triazole bactericides, is a sterol demethylation inhibitor, has the characteristics of high efficiency, broad spectrum, low toxicity and low dosage, is an excellent variety of triazole bactericides, has strong systemic property, and destroys the cell membrane structure and functions of pathogenic bacteria by inhibiting the biosynthesis of ergosterol of pathogenic bacteria cells. The bactericide can be used for crops such as fruit trees, vegetables, wheat, potatoes, beans, melons and the like, has good protection and treatment effects on various fungal diseases such as vegetables, melons and fruits, has the characteristics of no environmental pollution, no agricultural product pollution and no natural enemy killing, and is an ideal bactericide for preventing and treating crop resistance diseases such as citrus scab and alternaria leaf spot in China and even all over the world at present.

At present, dosage forms commonly used for difenoconazole comprise missible oil, wettable powder, granules and the like, the dosage forms belong to traditional pesticide dosage forms, corresponding problems still exist in the efficient popularization and application process of difenoconazole, and the dosage forms are inevitably subjected to photolysis, hydrolysis, volatilization, loss and microbial degradation in a target or a surrounding environment in the using process, so that the concentration of the dosage forms is reduced to be below the effective concentration, and the pesticide effect is difficult to fully exert. Therefore, the development of difenoconazole pesticide formulations with long action cycle and good adhesion performance is a problem to be solved by those skilled in the art.

Disclosure of Invention

The purpose of the invention is as follows: the first purpose of the invention is to provide a pesticide microcapsule with good adhesion performance and high encapsulation rate; the second purpose of the invention is to provide a preparation method of the pesticide microcapsule.

The technical scheme is as follows: the high-adhesiveness pesticide microcapsule provided by the invention comprises difenoconazole, a dispersing agent, water, a shell membrane material, a photoinitiator and a solvent, wherein the dispersing agent comprises alkylphenol polyoxyethylene ether sulfosuccinate, nonylphenol polyoxyethylene ether NP-10 and styrene phenol formaldehyde resin polyoxyethylene polyoxypropylene ether; the shell membrane material comprises polyester acrylate, trimethylolpropane triacrylate, tripropylene glycol diacrylate and dopamine hydrochloride; the photoinitiator comprises (2,4, 6-trimethylbenzoyl) diphenylphosphine oxide; the solvent comprises dipropylene glycol dimethyl ether.

The materials comprise, by weight, 3.5-4.5 parts of difenoconazole, 0.2-0.4 part of alkylphenol polyoxyethylene ether sulfosuccinate, 100.2-0.3 part of nonylphenol polyoxyethylene ether NP-, 0.5-0.7 part of styrene phenol formaldehyde resin polyoxyethylene polyoxypropylene ether, 6.5-8 parts of dipropylene glycol dimethyl ether, 3.5-5 parts of polyester acrylate, 3-5 parts of trimethylolpropane triacrylate, 3-5 parts of tripropylene glycol diacrylate, (2,4, 6-trimethylbenzoyl) diphenylphosphine oxide, 0.05-0.08 part of dopamine hydrochloride and 70.72-79.45 parts of water.

The preparation method of the high-adhesiveness pesticide microcapsule comprises the following steps:

(1) mixing water, alkylphenol polyoxyethylene ether sulfosuccinate, nonylphenol polyoxyethylene ether NP-10 and styrene phenol formaldehyde resin polyoxyethylene polyoxypropylene ether, and stirring for reaction to prepare a mixed solution 1;

(2) adding a mixed solution 2 consisting of difenoconazole, dipropylene glycol dimethyl ether, polyester acrylate, trimethylolpropane triacrylate, tripropylene glycol diacrylate and (2,4, 6-trimethylbenzoyl) diphenyl phosphine oxide into the mixed solution 1, and reacting to obtain a suspension dispersion liquid;

(3) carrying out ultraviolet curing polymerization reaction on the suspension dispersion liquid to prepare difenoconazole pesticide microcapsules;

(4) adding dopamine hydrochloride into the difenoconazole pesticide microcapsule, stirring for reaction, and then carrying out centrifugal separation to obtain the final product.

Preferably, in the step (1), the stirring reaction time is 20-25 min.

Preferably, in step (2), the reaction is a high speed emulsion reaction.

Preferably, the time of the high-speed emulsification reaction is 4-5 min.

Preferably, the rotation speed of the homogenizing emulsifying machine for the high-speed emulsification reaction is 14000-15000 r/min.

Preferably, in the step (3), the time of the ultraviolet curing polymerization reaction is 30-40 s; the light source of the ultraviolet light is an irradiation light source emitted by the UV photochemical reactor.

Preferably, in the step (4), the stirring reaction time is 24-25 h.

Preferably, in the step (4), the time for centrifugal separation is 1-2 min.

Has the advantages that: compared with the prior art, the invention has the following remarkable advantages:

(1) through the synergistic interaction among the components, the prepared microcapsule shell membrane has high coating rate and good forming degree, can perfectly coat the pesticide difenoconazole, and meanwhile, the microcapsule has excellent stability, can be stored at normal temperature for more than 6 months, and realizes the efficient utilization of the difenoconazole;

(2) by adding a small amount of dopamine hydrochloride, the adhesion performance of the microcapsule is greatly improved, the microcapsule can be adhered to the surface of a plant for a long time after being applied, and the problem of easy falling in actual operation is solved;

(3) the preparation method of the microcapsule utilizes a novel ultraviolet curing technology, has simple and efficient process, energy conservation, environmental protection and lower cost;

(4) the preparation method has high product conversion rate and few byproducts, and can be widely applied to actual production.

Drawings

FIG. 1 is a representation of a microscope of the highly adherent pesticide microcapsule of the present invention;

FIG. 2 is a microscope representation of other microcapsules on the market;

FIG. 3 is a microscope representation of the high-adhesiveness pesticide microcapsule formulation after being soaked;

FIG. 4 is a microscope representation of other microcapsules on the market after immersion.

Detailed Description

The technical scheme of the invention is further explained by combining the attached drawings.

The inventor researches and discovers that with the enhancement of awareness of food safety and environmental protection, the pesticide controlled release technology becomes one of important development directions of pesticide preparations. The pesticide microcapsule technology is a technology for coating solid or liquid pesticide with a film-forming material to form micro-particles. The pesticide enclosed inside the microcapsule is called capsule core, and the film forming material is called capsule wall. The pesticide microcapsule has the characteristics of prolonged pesticide effect, slow release, controlled release, pollution reduction, odor masking, stability improvement, prevention and treatment times reduction and pesticide dosage reduction, economy, safety and good prevention effect. In addition, the pesticide has a series of excellent performances of prolonging the effective period of the pesticide, preventing the pesticide from being damaged and lost by environmental factors such as atmosphere, sunlight, rainwater, microorganisms and the like, and effectively controlling the pollution of the pesticide to underground water.

At present, the capsule wall materials commonly used in pesticide microcapsules include natural or synthetic polymer materials such as gelatin, arabic gum, sodium alginate, polyurea, urea-formaldehyde resin, melamine-formaldehyde resin and the like. However, the pesticide microcapsules prepared by the capsule wall material generally have the problem of easy falling off in the using process, so that the pesticide microcapsules cannot be adhered to the surface of plants for a long time, and the actual acting efficiency of the pesticide microcapsules is seriously influenced. Therefore, the development of high-adhesion pesticide microcapsules is an urgent problem to be solved by those skilled in the art.

The invention uses high-adhesion polymer as capsule wall material, and uses novel microcapsule preparation technology to wrap difenoconazole into the capsule wall material, so as to prepare the difenoconazole pesticide microcapsule with core/shell structure. The microcapsule has the advantages of good adhesion, high encapsulation rate, and simple preparation process.

The pesticide microcapsules prepared by the invention and the pesticide microcapsules on the market are respectively placed on two glass slides with the same type, and the appearance of the two pesticide microcapsules is respectively observed through a microscope, and the result is shown in fig. 1 and fig. 2. Next, the two types of glass slides loaded with microcapsules were placed in a beaker containing 100mL of deionized water, and after 2 times of immersion cleaning, the remaining amounts of the two types of microcapsules on the glass slides were respectively observed by a microscope, as shown in fig. 3 and 4, thereby judging the adhesion stability of the microcapsules.

As can be seen by comparing FIG. 2 with FIG. 4, the remaining amount of microcapsules is very small after the glass slide carrying the microcapsules on the market is soaked. As can be seen from comparison between fig. 1 and fig. 3, the residual quantity of the microcapsules is still large and the change is small after the glass slide loaded with the microcapsules prepared by the present invention is soaked, which further illustrates that the microcapsules prepared by the present invention have better adhesion stability compared with the microcapsules in the market.

Example 1

79.45 parts of deionized water, 0.2 part of alkylphenol polyoxyethylene ether sulfosuccinate, 100.2 parts of nonylphenol polyoxyethylene ether NP-and 0.5 part of styrene phenol formaldehyde resin polyoxyethylene polyoxypropylene ether are accurately weighed into a three-neck flask and stirred for 20 minutes. Then, a mixed solution of 3.5 parts of difenoconazole, 6.5 parts of dipropylene glycol dimethyl ether, 3.5 parts of polyester acrylate, 3 parts of trimethylolpropane triacrylate, 3 parts of tripropylene glycol diacrylate and 0.1 part of (2,4, 6-trimethylbenzoyl) diphenylphosphine oxide is added into the system, and a high-speed emulsification reaction is carried out for 5 minutes to obtain a stable suspension dispersion. And (3) after the suspension dispersion liquid is subjected to ultraviolet curing polymerization reaction for 30s, adding 0.07 part of quantitative dopamine hydrochloride, continuously stirring for reaction for 25h, and centrifugally separating a product to obtain the high-adhesion difenoconazole pesticide microcapsule.

Example 2

70.72 parts of deionized water, 0.4 part of alkylphenol polyoxyethylene ether sulfosuccinate, 100.3 parts of nonylphenol polyoxyethylene ether NP and 0.7 part of styrene phenol formaldehyde resin polyoxyethylene polyoxypropylene ether are accurately weighed into a three-neck flask and stirred for 20 minutes. Then, a mixed solution of 4.5 parts of difenoconazole, 8 parts of dipropylene glycol dimethyl ether, 5 parts of polyester acrylate, 5 parts of trimethylolpropane triacrylate, 5 parts of tripropylene glycol diacrylate and 0.3 part of (2,4, 6-trimethylbenzoyl) diphenylphosphine oxide is added into the system, and the mixture is subjected to high-speed emulsification reaction for 5 minutes to obtain a stable suspension dispersion. And (3) after the suspension dispersion liquid is subjected to ultraviolet curing polymerization reaction for 30s, adding 0.07 part of quantitative dopamine hydrochloride, continuously stirring for reaction for 25h, and centrifugally separating a product to obtain the high-adhesion difenoconazole pesticide microcapsule.

Example 3

75.58 parts of deionized water, 0.3 part of alkylphenol polyoxyethylene ether sulfosuccinate, 0.6 part of nonylphenol polyoxyethylene ether NP-100.25 parts and 0.6 part of styrene phenol formaldehyde resin polyoxyethylene polyoxypropylene ether are accurately weighed into a three-neck flask and stirred for 20 minutes. Then, a mixed solution of 4 parts of difenoconazole, 7 parts of dipropylene glycol dimethyl ether, 4 parts of polyester acrylate, 4 parts of trimethylolpropane triacrylate, 4 parts of tripropylene glycol diacrylate and 0.2 part of (2,4, 6-trimethylbenzoyl) diphenylphosphine oxide is added into the system, and the mixture is subjected to high-speed emulsification reaction for 5 minutes to obtain a stable suspension dispersion. And (3) after the suspension dispersion liquid is subjected to ultraviolet curing polymerization reaction for 30s, adding 0.07 part of quantitative dopamine hydrochloride, continuously stirring for reaction for 25h, and centrifugally separating a product to obtain the high-adhesion difenoconazole pesticide microcapsule.

Example 4

73.03 parts of deionized water, 0.4 part of alkylphenol polyoxyethylene ether sulfosuccinate, 100.2 parts of nonylphenol polyoxyethylene ether NP-and 0.6 part of styrene phenol formaldehyde resin polyoxyethylene polyoxypropylene ether are accurately weighed into a three-neck flask and stirred for 20 minutes. Then, a mixed solution of 4.5 parts of difenoconazole, 8 parts of dipropylene glycol dimethyl ether, 4.5 parts of polyester acrylate, 3.5 parts of trimethylolpropane triacrylate, 5 parts of tripropylene glycol diacrylate and 0.2 part of (2,4, 6-trimethylbenzoyl) diphenylphosphine oxide is added into the system, and a high-speed emulsification reaction is carried out for 5 minutes to obtain a stable suspension dispersion. And (3) after the suspension dispersion liquid is subjected to ultraviolet curing polymerization reaction for 30s, adding 0.07 part of quantitative dopamine hydrochloride, continuously stirring for reaction for 25h, and centrifugally separating a product to obtain the high-adhesion difenoconazole pesticide microcapsule.

Example 5

73.69 parts of deionized water, 0.2 part of alkylphenol polyoxyethylene ether sulfosuccinate, 100.3 parts of nonylphenol polyoxyethylene ether NP and 0.5 part of styrene phenol formaldehyde resin polyoxyethylene polyoxypropylene ether are accurately weighed into a three-neck flask and stirred for 20 minutes. Then, a mixed solution of 4 parts of difenoconazole, 7.5 parts of dipropylene glycol dimethyl ether, 5 parts of polyester acrylate, 4 parts of trimethylolpropane triacrylate, 4.5 parts of tripropylene glycol diacrylate and 0.25 part of (2,4, 6-trimethylbenzoyl) diphenylphosphine oxide is added into the system, and the mixture is subjected to high-speed emulsification reaction for 5 minutes to obtain a stable suspension dispersion. And (3) after the suspension dispersion liquid is subjected to ultraviolet curing polymerization reaction for 30s, adding 0.07 part of quantitative dopamine hydrochloride, continuously stirring for reaction for 25h, and centrifugally separating a product to obtain the high-adhesion difenoconazole pesticide microcapsule.

TABLE 1 influence of the interaction of the components in different parts by weight on the encapsulation efficiency of microcapsules

Serial number	Microcapsule coating Rate (%)
		Example 1	95.2
Example 2	98.1
		Example 3	96.8
Example 4	95.7
		Example 5	98.4

As can be seen from Table 1, the encapsulation rate of the high-adhesiveness pesticide microcapsule prepared by the invention is higher (more than or equal to 95%), wherein the encapsulation rate of the embodiment 5 is the highest and reaches 98.4%.

Comparative example 1

In the comparative example, the polyester acrylate was replaced with amine modified polyether acrylate, and the other raw materials, ratios, and operation steps were the same as those in example 1.

Comparative example 2

In the comparative example, trimethylolpropane triacrylate was replaced with polyethylene glycol dipropionate, and the other raw materials, ratios, and operation steps were the same as in example 1.

Comparative example 3

In the comparative example, tripropylene glycol diacrylate was replaced by pentaerythritol hexaacrylate, and the other raw materials, ratios, and operation steps were the same as those in example 1.

Comparative example 4

In the comparative example, the polyester acrylate and the trimethylolpropane triacrylate were replaced by the amine-modified polyether acrylate and the polyethylene glycol dipropionate, and the other raw materials, the mixture ratio, and the operation steps were the same as those in example 1.

Comparative example 5

In the comparative example, the polyester acrylate and the tripropylene glycol diacrylate are replaced by the amine-modified polyether acrylate and the pentaerythritol hexaacrylate, and other raw materials, proportions and operation steps are the same as those in example 1.

Comparative example 6

In the comparative example, tripropylene glycol diacrylate and trimethylolpropane triacrylate were replaced with pentaerythritol hexaacrylate and polyethylene glycol dipropionate, and the other raw materials, ratios, and operation steps were the same as those in example 1.

Table 2 investigation of the synergistic Effect of Shell Membrane materials

As can be seen from Table 2, the microcapsule encapsulation ratios of comparative examples 1 to 6 are all lower than the microcapsule encapsulation ratio of example 1, and thus it can be seen that the shell material polyester acrylate, trimethylolpropane triacrylate and tripropylene glycol diacrylate have a synergistic effect, and when the three are added simultaneously, the microcapsule encapsulation ratio is high.

Comparative example 7

In the comparative example, the addition amount of the dopamine hydrochloride is 0.03 part, and other raw materials, mixture ratio and operation steps are the same as those in the example 1.

Comparative example 8

In the comparative example, the addition amount of the dopamine hydrochloride is 0.05 part, and other raw materials, mixture ratio and operation steps are the same as those in the example 1.

Comparative example 9

In the comparative example, the addition amount of the dopamine hydrochloride is 0.06 part, and other raw materials, mixture ratio and operation steps are the same as those in the example 1.

Comparative example 10

In the comparative example, the addition amount of the dopamine hydrochloride is 0.08 part, and other raw materials, mixture ratio and operation steps are the same as those in the example 1.

Comparative example 11

In the comparative example, the addition amount of the dopamine hydrochloride is 0.10 part, and other raw materials, mixture ratio and operation steps are the same as those in the example 1.

Comparative example 12

In the comparative example, dopamine hydrochloride was replaced by chitosan, and the other raw materials, ratios and operation steps were the same as those in example 1.

Table 3 study of the effect of dopamine hydrochloride on microcapsule adhesion

As can be seen from Table 2:

in comparative example 7, the addition amount of dopamine hydrochloride was too small (0.03 parts), and the adhesion of the microcapsules could not be effectively increased.

In comparative example 8, the amount of dopamine hydrochloride added was too large, but the adhesion did not increase significantly, but the production cost increased.

In comparative example 9, the adhesive was replaced with chitosan, with an adhesion of 53.8%.

In conclusion, the selected polyester acrylate, trimethylolpropane triacrylate, tripropylene glycol diacrylate and dopamine hydrochloride shell membrane material have good synergistic effect, and when the four materials are added simultaneously, the microcapsule has high adhesion performance.

Claims

1. A high-adhesiveness pesticide microcapsule comprises difenoconazole, a dispersant, water, a shell membrane material, a photoinitiator and a solvent, and is characterized in that the dispersant comprises alkylphenol polyoxyethylene ether sulfosuccinate, nonylphenol polyoxyethylene ether NP-10 and styrene phenol formaldehyde resin polyoxyethylene polyoxypropylene ether; the shell membrane material comprises polyester acrylate, trimethylolpropane triacrylate, tripropylene glycol diacrylate and dopamine hydrochloride; the photoinitiator comprises (2,4, 6-trimethylbenzoyl) diphenylphosphine oxide; the solvent comprises dipropylene glycol dimethyl ether.

2. The highly adherent pesticide microcapsule according to claim 1, comprising, by weight, 3.5 to 4.5 parts of difenoconazole, 0.2 to 0.4 part of alkylphenol polyoxyethylene ether sulfosuccinate, 100.2 to 0.3 part of nonylphenol polyoxyethylene ether NP-100.2 to 0.7 part of styrene phenol formaldehyde resin polyoxyethylene polyoxypropylene ether, 6.5 to 8 parts of dipropylene glycol dimethyl ether, 3.5 to 5 parts of polyester acrylate, 3 to 5 parts of trimethylolpropane triacrylate, 3 to 5 parts of tripropylene glycol diacrylate, 0.1 to 0.3 part of (2,4, 6-trimethylbenzoyl) diphenylphosphine oxide, 0.05 to 0.08 part of dopamine hydrochloride, and 70.72 to 79.45 parts of water.

3. The preparation method of the high-adhesiveness pesticide microcapsule according to claim 1, which is characterized by comprising the following steps:

4. The method for preparing a highly adhesive pesticide microcapsule according to claim 3, wherein the stirring reaction time in step (1) is 20-25 min.

5. The method for preparing a highly adhesive pesticidal microcapsule according to claim 3, wherein in step (2), the reaction is a high-speed emulsification reaction.

6. The method for preparing the highly adhesive pesticide microcapsule according to claim 5, wherein the high speed emulsification reaction time is 4-5 min.

7. The method for preparing highly adhesive pesticide microcapsules of claim 5, wherein the rotation speed of the homogenizer for the high speed emulsification reaction is 14000-15000 r/min.

8. The method for preparing a highly adhesive pesticide microcapsule according to claim 3, wherein in the step (3), the time of the ultraviolet light polymerization reaction is 30-40 s; the light source of the ultraviolet light is an irradiation light source emitted by the UV photochemical reactor.

9. The method for preparing highly adhesive pesticide microcapsules of claim 3, wherein in the step (4), the stirring reaction time is 24-25 hours.

10. The method for preparing a highly adhesive pesticide microcapsule according to claim 3, wherein the time for the centrifugal separation in step (4) is 1-2 min.