CN111296429A - A kind of light-responsive insect virus insecticide and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of biological pesticides, in particular to a light-responsive insect virus pesticide and a preparation method thereof. The preparation method of the insect virus insecticide comprises the following steps: (1) adding the insect virus dry powder into dimethylformamide, stirring and mixing evenly to form a mixture; (2) mixing tetraethylthiuram disulfide, ethylene glycol , triethanolamine, hexamethylene diisocyanate and dibutyltin dilaurate are added to the mixture; (3) after 12 to 24 hours of reaction, the obtained product is immersed in acetonitrile for more than 24 hours to obtain a transparent gel-like object. The insect virus insecticide of the invention is safe and environmentally friendly, has good light response performance, can effectively protect the insect virus from being killed by ultraviolet rays, prolongs the storage time of the virus insecticide, and improves the insecticidal efficiency.

Description

A kind of light-responsive insect virus insecticide and preparation method thereof

technical field

The invention relates to the technical field of biological pesticides, in particular to a light-responsive insect virus pesticide and a preparation method thereof.

Background technique

The country is currently committed to developing a healthy China, advocating green development, developing, producing and applying biological pesticides, protecting the ecological environment and promoting sustainable agricultural development, which will become a new trend in my country's industrial development. Although chemical pesticides still occupy a dominant position in the pesticide industry, biological pesticides have the advantages of low toxicity to humans and animals, good environmental compatibility, and relatively less resistance to pests and diseases, so they are more in line with the requirements of modern society for agricultural production and pesticides.

As biological pesticides, insect viruses are constantly being researched and promoted in terms of market and application. They are used in various fields and have very broad prospects. Insect virus insecticides are made by artificial cultivation, collection, purification and processing of specific insect viruses. It adopts a new insecticidal concept of "fighting poison with poison", with a unique mechanism of action, good control effect, and no harm to humans and natural enemies. Harmful, and has a significant advantage that it is very safe for the quality of agricultural products and the agricultural ecological environment, can survive in the environment for several years, and can control the pest population for a long time. effect.

However, the anti-ultraviolet performance of the existing insect virus insecticides is insufficient, and there are problems such as instability in the field. Insect viruses are very sensitive to drying, sunlight or ultraviolet light. For example, virus polyhedra are easily inactivated under ultraviolet light, which affects the promotion and application of insect viruses. Therefore, it is necessary to develop a safe, environmentally friendly and light-responsive insecticide for insect viruses.

SUMMARY OF THE INVENTION

In order to solve the above technical problems, the present invention provides a light-responsive insect virus insecticide and a preparation method thereof.

In order to realize the technical effect of the present invention, the following technical solutions are adopted to realize:

A preparation method of a light-responsive insect virus insecticide, comprising the following steps:

(1) adding insect virus dry powder into dimethylformamide (DMF) solvent, stirring and mixing to form a mixture;

(2) tetraethylthiuram disulfide, ethylene glycol, triethanolamine, hexamethylene diisocyanate, dibutyltin dilaurate are added in the mixture to react;

(3) After 12-24 hours of reaction, the obtained product is immersed in acetonitrile for more than 24 hours to obtain a transparent gel-like object.

Since some of the substances added in the step (2) are soluble in water, some are insoluble in water and soluble in organic solvents, and hexamethylene diisocyanate will also react with water, the use of dimethylformamide can well The substance dissolves, so the use of dimethylformamide as the solvent can make the reaction proceed smoothly.

At the same time, it was found in the experiment that dibutyltin dilaurate can be used well as a catalyst, while other substances used as catalysts cannot be used well as catalysts.

The reaction described in step (3) can be carried out at room temperature (25°C). Steps (1) (2) (3) can be performed at room temperature. The product was immersed in acetonitrile for more than 24 hours at room temperature.

The amount of acetonitrile is generally the immersion product.

As a further improvement, the ratio of the mass of the insect virus dry powder to the volume of the dimethylformamide solvent is 0.1 g: (2-6) mL (that is, the mass and volume can be increased by the same multiples, for example, when the insect virus dry powder is added When the mass is 1 gram, add 20-60 mL of dimethylformamide, and the ratio of mass and volume will be the same in the following text); the mass ratio of insect virus dry powder and tetraethylthiuram disulfide is 100: (197 ~591).

As a further improvement, the insect virus dry powder is Spodoptera litura polyhedrosis virus dry powder and/or beet armyworm polyhedrosis virus dry powder.

As a further improvement, the mass ratio of the tetraethylthiuram disulfide, ethylene glycol, triethanolamine, and hexamethylene diisocyanate is (197-591): (175-757): (120-160) : (800-2000); the mass of the dibutyltin dilaurate is 0.5% of the mass of the hexamethylene diisocyanate.

As a further improvement, the molar ratio of the tetraethylthiuram disulfide to ethylene glycol is (0.05-0.7):1.

As a further improvement, the volume ratio of the tetraethylthiuram disulfide to acetonitrile is (197-591) mg:20 mL.

As a further improvement, the acetonitrile contains 5% methanol.

As a further improvement, the gelatinous object is straw-colored.

The present invention also provides an insect virus insecticide prepared by the above-mentioned preparation method.

Compared with the prior art, the beneficial effects of the present invention are as follows:

The light-responsive insect virus insecticide of the present invention can be applied to control insects such as Spodoptera litura and Spodoptera litura. The preservation time of virus insecticides increases the insecticidal efficiency.

Detailed ways

In the present invention, covalently cross-linked polyurethane (also called polyurethane, which is a polyurethane with a lower glass transition temperature) is synthesized by reaction, so that the insect virus is mainly wrapped by the covalently cross-linked polyurethane.

The present invention incorporates a reactive tetraethylthiuram disulfide unit capable of reformation in the main chain of polyurethane with lower glass transition temperature, and dissolves the insect virus prepared by the present invention under visible light, air, room temperature and no solvent The self-healing of covalently cross-linked polyurethanes is accomplished using free radical shuffling of tetraethylthiuram disulfide bond units in the presence of pesticides. The shuffling of the tetraethylthiuram disulfide bond unit can proceed through two mechanisms, one is through a radical transfer reaction, in which the generated S-based radical reacts with the tetraethylthiuram disulfide bond unit to A new tetraethylthiuram disulfide bond unit is formed. Subsequently, the newly generated S-based radical reacts with another tetraethylthiuram disulfide bond unit during the transfer process. Another possibility is a simple radical exchange reaction. The free radical shuffling of the tetraethylthiuram disulfide bond unit is carried out under ambient visible light, and the self-repair of the covalently cross-linked polyurethane is completed under the light irradiation, and the outdoor storage time of the insect virus insecticide is prolonged.

The present invention will be further described below in conjunction with specific embodiments.

It should be noted that, unless otherwise specified, the raw materials used in the technical solutions provided by the present invention are all prepared by conventional means or purchased through commercial channels.

A preparation method of a light-responsive insect virus insecticide, comprising the following steps:

(1) adding the insect virus dry powder into the dimethylformamide solvent, stirring and mixing to form a mixture;

(2) Tetraethylthiuram disulfide, ethylene glycol, triethanolamine, hexamethylene diisocyanate, dibutyltin dilaurate are added in the mixture and react; Concrete adding step can be the step (2) of the embodiment -(4);

(3) After 12-24 hours of reaction, the obtained product is immersed in acetonitrile for more than 24 hours to obtain a transparent gel-like object.

Example 1

A preparation method of a light-responsive insect virus insecticide, comprising the following steps:

(1) Add 0.1 g of Spodoptera litura polyhedrosis virus dry powder into 2.2 mL of dimethylformamide solvent, stir and mix well to form mixture A;

(2) 591 mg of tetraethylthiuram disulfide and 524 mg of ethylene glycol were added to mixture A, stirred and mixed to obtain mixture B;

(3) add triethanolamine 149mg and hexamethylene diisocyanate 1.01g to mixture B again, stir and mix uniformly to obtain mixture C;

(4) 5 mg of dibutyltin dilaurate was added dropwise to mixture C, and the reaction was stirred. After 24 hours of stirring reaction, the obtained product was immersed in 20 mL of acetonitrile solution containing 5% methanol for 48 hours to obtain a transparent straw-colored coagulation. gelatinous object.

Example 2

A preparation method of a light-responsive insect virus insecticide, comprising the following steps:

(1) Add 0.1 g of Spodoptera litura polyhedrosis virus dry powder into 2.2 mL of dimethylformamide solvent, stir and mix well to form mixture A;

(2) adding 197 mg of tetraethylthiuram disulfide and 757 mg of ethylene glycol into mixture A, stirring and mixing to obtain mixture B;

(3) add triethanolamine 149mg and hexamethylene diisocyanate 1.01g to mixture B again, stir and mix to obtain mixture C;

(4) drop 5mg of dibutyltin dilaurate into mixture C again, stirring reaction, after stirring reaction for 24 hours, the product obtained after the reaction is immersed in 20mL acetonitrile solution containing 5% methanol for 48 hours to obtain transparent straw color gelatinous substance.

Example 3

A preparation method of a light-responsive insect virus insecticide, comprising the following steps:

(1) Add 0.1 g of Spodoptera litura polyhedrosis virus dry powder into 2.2 mL of dimethylformamide solvent, stir and mix well to form mixture A;

(2) add 873mg of ethylene glycol in mixture A to obtain mixture B, stir and mix uniformly;

(3) add triethanolamine 149mg and hexamethylene diisocyanate 1.01g to mixture B again, stir and mix uniformly to obtain mixture C;

(4) drop 5mg of dibutyltin dilaurate into mixture C again, stirring reaction, after stirring reaction for 24 hours, the product obtained after the reaction is immersed in 20mL acetonitrile solution containing 5% methanol for 48 hours to obtain transparent straw color gelatinous substance.

Example 4

A preparation method of a light-responsive insect virus insecticide, comprising the following steps:

(1) adding 0.1 g of Spodoptera litura polyhedrosis virus dry powder into a container containing 2.2 mL of dimethylformamide solvent, stirring and mixing to form a mixture;

(2) add tetraethylthiuram disulfide 197mg and ethylene glycol 175mg in the container, stir and mix well;

(3) add triethanolamine 149mg and hexamethylene diisocyanate 1.01g again in the container, stir and mix uniformly;

(4) drop 5mg of dibutyltin dilaurate into the container, stir and react, and after stirring for 24 hours, the product obtained after the reaction is immersed in 20 mL of acetonitrile solution containing 5% methanol for 48 hours to obtain a transparent straw-colored condensate. gelatinous object.

Example 5

Except that the quality of adding triethanolamine is 120 mg, the quality of adding hexamethylene diisocyanate is 800 mg, and the quality of dripping dibutyltin dilaurate is 0.5% of the quality of hexamethylene diisocyanate, the rest of the preparation methods and the substance dosage Example 1 is the same.

Example 6

Except that the quality of adding triethanolamine is 160mg, the quality of adding hexamethylene diisocyanate is 2000mg, and the quality of dripping dibutyltin dilaurate is 0.5% of the quality of hexamethylene diisocyanate, the rest of the preparation method and Example 1 same.

Example 7

Except that the reaction time of step (4) is 12 hours, the time of immersion in 20 mL of acetonitrile solution containing 5% methanol is 24 hours, and the solvent of dimethylformamide is 2 mL, other preparation methods and substances are the same as in Example 1.

Example 8

Except that the dimethylformamide solvent is 6 mL, the other preparation methods and material consumptions are the same as those in Example 1.

The acetonitrile containing 5% methanol in the present invention refers to the acetonitrile solution containing 5% methanol, that is, the mass percentage of methanol in the acetonitrile solution containing 5% methanol is 5%.

Examples 1-8 Steps (1)(2)(3)(4) can be performed at room temperature.

The products obtained after the reaction in steps (4) of Examples 1-8 include cross-linked polymers.

Anti-ultraviolet performance test:

The samples are: light-responsive insect virus insecticides prepared in Examples 1-8.

Bioassays were performed after each sample was irradiated with UV light at the same height for 3 h to determine viral activity. Use a brush to evenly brush each sample of the same quality on the surface of 8 Spodoptera litura feeds with the same size and shape, and then insert 20 3-year-old Spodoptera litura larvae (test worms) onto the surface of each feed. Group experiments were repeated 3 times.

The temperature of the culture room was kept at 25°C, the light was 12L:12D, and the light time was 24 hours. The death of the larvae was recorded until all of them died or pupated. The specific results are shown in Table 1 below:

Table 1

As can be seen from the above table: Example 3 does not add tetraethylthiuram disulfide, resulting in the synthesis of polyurethane without photoresponsivity, and cannot be cross-linked under ultraviolet irradiation, so the test insect mortality rate is 5%; The insect mortality rate reached 20-55%, indicating that the insect virus insecticide of the present invention has good light response.

In particular, the lethality rate of the test worms in Example 1 reaches 55%, which shows that the virus in the virus microcapsules of the insect virus insecticide of the present invention still has most of the activities, and wrapping the virus with polyurethane can effectively protect the virus from being killed by ultraviolet rays, Furthermore, the mortality rate of the test worms is also high.

The used virus dry powder can also be other virus dry powders such as beet armyworm polyhedrosis virus dry powder.

It was found in the experiment that if the dry powder of Spodoptera litura polyhedrosis virus in Example 1-8 was changed to the dry powder of Spodoptera litura polyhedrosis virus, the same method was used to carry out the anti-ultraviolet performance test (the test larvae were changed to Spodoptera litura larvae, and the feed was changed to beet armyworm larvae. for beet armyworm feed), the test results were found to be the same as when the beet armyworm polyhedrosis virus dry powder was used.

The technical solutions provided by the embodiments of the present invention have been introduced in detail above. The principles and implementations of the embodiments of the present invention are described in this paper by using specific examples. The descriptions of the above embodiments are only applicable to help understand the embodiments of the present invention. At the same time, for those of ordinary skill in the art, according to the embodiments of the present invention, there will be changes in the specific implementation and application scope. To sum up, the content of this specification should not be construed as a limitation of the present invention.

Claims (9)

1. a preparation method with light-responsive insect virus insecticide, is characterized in that, comprises the following steps: (1) adding the insect virus dry powder into the dimethylformamide solvent, stirring and mixing to form a mixture; (2) tetraethylthiuram disulfide, ethylene glycol, triethanolamine, hexamethylene diisocyanate, dibutyltin dilaurate are added in the mixture to react; (3) After 12-24 hours of reaction, the obtained product is immersed in acetonitrile for more than 24 hours to obtain a transparent gel-like object. 2. the preparation method with light-responsive insect virus insecticide according to claim 1, is characterized in that, the quality of described insect virus dry powder and the volume ratio of dimethylformamide solvent are 0.1g: (2～ 6) mL; the mass ratio of insect virus dry powder and tetraethylthiuram disulfide is 100:(197-591). 3. The preparation method of the light-responsive insect virus insecticide according to claim 1, wherein the insect virus dry powder is Spodoptera litura polyhedrosis virus dry powder and/or beet armyworm polyhedrosis virus dry powder. 4. the preparation method with light-responsive insect virus insecticide according to claim 1, is characterized in that, described tetraethylthiuram disulfide, ethylene glycol, triethanolamine, hexamethylene diisocyanate The mass ratio is (197-591): (175-757): (120-160): (800-2000); the mass of the dibutyltin dilaurate is 0.5% of the mass of the hexamethylene diisocyanate. 5. the preparation method with light-responsive insect virus insecticide according to claim 1, is characterized in that, the mol ratio of described tetraethylthiuram disulfide and ethylene glycol is (0.05-0.7): 1. 6 . The preparation method of a light-responsive insect virus insecticide according to claim 1 , wherein the acetonitrile contains 5% methanol. 7 . 7 . The preparation method of the light-responsive insect virus insecticide according to claim 1 , wherein the gel-like object is straw-colored. 8 . 8. the preparation method with light-responsive insect virus insecticide according to claim 1, is characterized in that, the reaction described in step (3) is carried out at room temperature; The product is immersed in acetonitrile and placed at room temperature 24-48 hours; the volume ratio of the tetraethylthiuram disulfide and acetonitrile is (197-591) mg:20 mL. 9. A light-responsive insect virus insecticide, characterized in that the insect virus insecticide is prepared by the preparation method described in any one of claims 1-8.