A liquid formulation of an avian repellent composition and a method of making the same

Abstract

The present application relates to the technical field of bird repellent, in particular to a kind of bird repellent composition liquid preparation and preparation method thereof.The present application is first prepared dodecyl succinyl β-cyclodextrin and catechol carboxymethyl chitosan;Second, repel active substance is included in modified cyclodextrin, and catechol carboxymethyl chitosan is positioned to the outside of inclusion particle by activating carboxyl, and forms polysaccharide outer layer;Finally, ammonium ferric citrate is sequentially added, and iron trichloride is added in segments to build iron-catechol layered coordination locking layer;The modified repel active substance inclusion particle obtained is sequentially modified repel active substance core layer, cyclodextrin inclusion layer, chitosan outer layer and coordination locking layer from inside to outside;The preparation has good water dispersibility, wet adhesion and rain after sustained release capacity, and is suitable for orchard, granary and airport and other long-acting bird repellent scene.

Description

Technical Field

[0001] This invention relates to the field of bird repellent technology, specifically to a liquid bird repellent composition and its preparation method. Background Technology

[0002] Plant-derived bird repellent liquid formulations typically use repellent active substances, such as volatile irritants like chili extract, peppermint oil, and cinnamon oil, as the main active source. After spraying, they rely on odor stimulation and taste avoidance to reduce bird dwelling and pecking behavior. Compared to mechanical or sound-and-light bird repellent methods, these formulations are more flexible in use, leave less environmental residue, and are suitable for open agricultural settings. However, their active ingredients are mostly volatile oils, which are easily affected by sunlight, airflow, rain, and surface water film in settings such as orchards, grain drying yards, grain warehouse perimeters, and airport lawns, leading to rapid odor decay and frequent re-spraying.

[0003] To prolong the duration of action of plant-derived volatile oils, existing technologies often employ emulsification, thickening, or cyclodextrin inclusion to improve their water dispersibility and slow-release properties. While ordinary emulsification systems can form sprayable liquids, oil droplets tend to coalesce during dilution and storage, and may also produce oil stains and an overpowering initial odor after spraying. Ordinary β-cyclodextrins can accommodate some hydrophobic volatiles, but their outer edges are hydrophilic, making them easily washed away by rain after being sprayed onto leaves, grains, glass, metal, or cement surfaces, thus failing to retain the effective components for a long time.

[0004] Chitosan or carboxymethyl chitosan can improve film-forming properties and adhesion to some extent. However, if directly mixed with volatile oils such as repellent active substances, the flexible polysaccharide segments may first encapsulate or adsorb the oil phase, affecting the entry of volatile oils into the inclusion cavity and causing uneven release channels or formulation flocculation. Although metal ions such as iron salts can enhance the stability of the polysaccharide layer, their one-time addition can easily generate local strong coordination and particle bridging, which in turn reduces the uniformity of dispersion. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a bird repellent composition liquid formulation and its preparation method, so as to solve the problems that the plant-derived aldehydes, phenols, terpenoids and capsaicin repellent active substances in existing plant-derived bird repellent liquid formulations are easy to volatilize and be easily lost by rain, and that ordinary encapsulation or thickening methods are difficult to take into account water dispersion stability, surface adhesion and long-lasting bird repellent effect.

[0006] To achieve the above objectives, the present invention provides a method for preparing a liquid formulation of a bird-repelling composition, comprising the following steps:

[0007] (1) Preparation of dodecenyl succinylated β-cyclodextrin: β-cyclodextrin was dissolved in anhydrous dimethyl sulfoxide and reacted with dodecenyl succinic anhydride in the presence of triethylamine and 4-dimethylaminopyridine. After precipitation, washing, dialyzing and drying, dodecenyl succinylated β-cyclodextrin was obtained.

[0008] (2) Preparation of catecholized carboxymethyl chitosan: Carboxymethyl chitosan was dissolved in 2-morpholine ethanesulfonic acid buffer, dopamine hydrochloride was added, and the reaction was carried out in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide. After dialysis and freeze drying, catecholized carboxymethyl chitosan was obtained.

[0009] (3) Preparation of modified repellent active substance inclusion dispersion: The dodecenyl succinylated β-cyclodextrin was dispersed in an aqueous system containing ethanol and propylene glycol to obtain a modified cyclodextrin dispersion; the repellent active substance was dissolved in ethanol to obtain an ethanol solution of the repellent active substance, and the ethanol solution of the repellent active substance was added dropwise to the modified cyclodextrin dispersion under low-temperature stirring to obtain a repellent active substance inclusion dispersion; 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride was added to the repellent active substance inclusion dispersion. Salt and N-hydroxysuccinimide are used to activate the outer carboxyl groups of dodecenylsuccinylated β-cyclodextrin; then, the catecholized carboxymethyl chitosan is added and reacted, followed by ultrafiltration to obtain a dispersion of repellent active substance inclusion particles with a catecholized carboxymethyl chitosan outer layer; ferric ammonium citrate solution, a first iron source solution, sodium bicarbonate and a second iron source solution are sequentially added to the dispersion of repellent active substance inclusion particles with a catecholized carboxymethyl chitosan outer layer to obtain a modified repellent active substance inclusion particle dispersion;

[0010] (4) Preparation of bird repellent liquid formulation: Add surfactant, preservative and solubilizer to the modified repellent active substance inclusion particle dispersion, and add deionized water to make up the amount. After stirring and filtering, the bird repellent liquid formulation is obtained.

[0011] By weight, the amounts of dodecenyl succinylated β-cyclodextrin, repellent active substance, catecholized carboxymethyl chitosan, ferric ammonium citrate solution, first iron source solution and second iron source solution in step (3) are 42-48 parts, 8-10 parts, 5-7 parts, 5 parts, 5 parts and 5 parts respectively; the amounts of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide are 0.6-0.7 parts and 0.33-0.42 parts respectively.

[0012] Preferably, by weight, the dodecenyl succinylated β-cyclodextrin in step (1) is prepared from 47-53 parts of β-cyclodextrin and 2.6-3.4 parts of dodecenyl succinic anhydride; the amount of triethylamine is 6-7 parts and the amount of 4-dimethylaminopyridine is 0.7-0.8 parts.

[0013] Preferably, the dialysis in step (1) is carried out in a dialysis bag with a molecular weight cutoff of 500-1000 Da, with 50% ethanol aqueous solution for 10-14 h, followed by dialysis with deionized water for 10-14 h.

[0014] Preferably, by weight, the catecholized carboxymethyl chitosan in step (2) is prepared from 9-11 parts of carboxymethyl chitosan and 1.3-1.7 parts of dopamine hydrochloride; the amount of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride is 1.7-2.1 parts and the amount of N-hydroxysuccinimide is 0.9-1.3 parts.

[0015] Preferably, the pH of the 2-morpholine ethanesulfonic acid buffer solution in step (2) is 5.8-6.0.

[0016] Preferably, the dialysis in step (2) is performed in a dialysis bag with a molecular weight cutoff of 8000-14000 Da, using deionized water with a pH of 5.8-6.0 for 22-26 hours, followed by dialysis with deionized water for 10-14 hours.

[0017] Preferably, based on 5 parts by weight, the content of ferric ammonium citrate in the ferric ammonium citrate solution in step (3) is 0.06-0.1 parts, and the remainder is deionized water; the content of ferric chloride hexahydrate in the first iron source solution is 0.003-0.005 parts, and the remainder is deionized water; and the content of ferric chloride hexahydrate in the second iron source solution is 0.012-0.016 parts, and the remainder is deionized water.

[0018] By weight, the repellent active substance in step (4) includes 5 parts cinnamaldehyde, 2.5 parts capsicum oleoresin, 1 part eugenol, and 0.5 parts menthol.

[0019] Preferably, the surfactant in step (4) is one of alkyl glycoside, Tween, or polysorbate.

[0020] Preferably, the preservative in step (4) is one of potassium sorbate, sodium benzoate, and sodium dehydroacetate.

[0021] Preferably, the co-solvent in step (4) is one of propylene glycol, glycerin, and polyethylene glycol.

[0022] A bird repellent composition liquid formulation comprising modified repellent active substance inclusion particles, wherein the modified repellent active substance inclusion particles comprise, from the inside out, a repellent active substance inclusion core layer, a dodecenyl succinylated β-cyclodextrin inclusion layer, a catecholized carboxymethyl chitosan outer layer, and an iron-catechin coordination locking layer.

[0023] The beneficial effects of this invention are:

[0024] This invention employs dodecenyl succinylated β-cyclodextrin to encapsulate repellent active substances. The dodecenyl succinylated group is located on the outer edge of the β-cyclodextrin, which not only retains the retention effect of the cyclodextrin cavity on plant-derived aldehydes, phenols, terpenoids and capsaicin repellent active substances, but also forms a hydrophobic slow-release interface on the outer side of the particle, which helps to reduce the initial odor release and improve the retention ability of the effective components in the open environment after spraying.

[0025] After the repellent active substance is encapsulated, the present invention uses catecholized carboxymethyl chitosan to position it on the outside of the encapsulated particles, so that the polysaccharide layer mainly undertakes the wet adhesion and subsequent coordination and positioning functions, avoiding competitive adsorption of the repellent active substance or blocking the β-cyclodextrin inlet before encapsulation. This treatment is beneficial to improving the dispersion uniformity of the formulation after dilution and improving its adhesion stability on leaves.

[0026] This invention further employs a pre-coordination method using ferric ammonium citrate and a layered coordination method using ferric chloride hexahydrate, which allows the trivalent iron coordination sites to gradually form along the outer layer of catecholized carboxymethyl chitosan, reducing particle flocculation and release channel obstruction caused by one-time strong coordination. As a result, the obtained liquid formulation can maintain good residue of effective components and continuous repellency in spraying, dilution, raining, and open field environments, making it suitable for long-term bird repellency scenarios such as orchards, grain drying yards, grain warehouse perimeters, and airport lawns. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0028] The sources and parameters of the raw materials used in this embodiment are as follows:

[0029] β-Cyclodextrin: purity not less than 98%; carboxymethyl chitosan: weight average molecular weight of 120,000 Da, degree of carboxymethyl substitution not less than 80%, residual free amino content not less than 0.15 mmol / g, and moisture content not more than 10%; by weight, the repellent active substances include 5 parts cinnamaldehyde, 2.5 parts capsicum oleoresin, 1 part eugenol, and 0.5 parts menthol.

[0030] Example 1: A method for preparing a liquid formulation of a bird repellent composition, the specific steps of which are as follows:

[0031] Preparation of dodecenyl succinylated β-cyclodextrin using S1:

[0032] 50g of β-cyclodextrin was placed in a vacuum drying oven and dried at 60℃ for 6h. After cooling to room temperature, it was added to 600g of anhydrous dimethyl sulfoxide and stirred at 300r / min under nitrogen protection until completely dissolved. Then, 6.5g of triethylamine and 0.75g of 4-dimethylaminopyridine were added, and the system temperature was controlled at 35℃. Separately, 3g of dodecenylsuccinic anhydride was added to 60g of anhydrous dimethyl sulfoxide and stirred until transparent. Then, it was added dropwise to the β-cyclodextrin solution over 30min. After the addition was complete, the reaction was continued at 35℃ for 6h. After the reaction was completed, the reaction solution was slowly poured into acetone to precipitate the product. The precipitate was collected by centrifugation at 5000 r / min for 10 min. The product was then washed twice with acetone and once with ethanol. Subsequently, the precipitate was redispersed in 500 g of 50% ethanol aqueous solution and placed in a dialysis bag with a molecular weight cutoff of 500-1000 Da. The product was dialyzed with 50% ethanol aqueous solution for 12 h, then dialyzed with deionized water for 12 h, and finally dried under vacuum at 40 °C for 12 h to obtain dodecenyl succinylated β-cyclodextrin.

[0033] S2 Preparation of Catecholized Carboxymethyl Chitosan:

[0034] 7.8 g of 2-morpholine ethanesulfonic acid was added to 800 g of deionized water, and sodium hydroxide was added to adjust the pH of the system to 5.8-6.0. The mixture was stirred until dissolved to obtain a 2-morpholine ethanesulfonic acid buffer solution. 10 g of carboxymethyl chitosan was added to the 2-morpholine ethanesulfonic acid buffer solution and stirred at 400 rpm for 2 hours until completely dissolved. Nitrogen gas was then purged for 15 minutes to reduce the dissolved oxygen content. Subsequently, 1.5 g of dopamine hydrochloride was added, and the mixture was stirred for 15 minutes under light-protected conditions. Then, 1.9 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 1.1 g of [other chemicals] were added sequentially. N-hydroxysuccinimide was reacted at room temperature, in the dark, and under nitrogen protection for 12 hours. After the reaction, the reaction solution was placed in a dialysis bag with a molecular weight cutoff of 8000-14000 Da and dialyzed with deionized water at pH 5.8-6.0 for 24 hours, then dialyzed with deionized water for 12 hours. After freeze drying, catecholized carboxymethyl chitosan was obtained.

[0035] S3 Preparation of modified repellent active substance inclusion particle dispersion:

[0036] 45g of dodecenylsuccinylated β-cyclodextrin was added to 500g of deionized water, followed by 40g of anhydrous ethanol and 20g of propylene glycol. The mixture was stirred at 500r / min for 30min at 25℃ to obtain a modified cyclodextrin dispersion. Separately, 9g of the repellent active ingredient was added to 20g of anhydrous ethanol and stirred at 300r / min for 15min to obtain an ethanol solution of the repellent active ingredient. The temperature of the modified cyclodextrin dispersion was lowered to 8℃, and the ethanol solution of the repellent active ingredient was added dropwise to the modified cyclodextrin dispersion over 45min while stirring at 600r / min. After the addition was complete, stirring was continued for 4h to obtain an inclusion dispersion of the repellent active ingredient. The temperature of the obtained inclusion dispersion of the repellent active ingredient was controlled at 10℃, and 0.65g of... 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.38 g N-hydroxysuccinimide were stirred at 400 r / min for 20 min. Separately, 6 g of catecholized carboxymethyl chitosan was added to 120 g of deionized water and stirred until completely dispersed. This was then added dropwise to the activated repellent active substance inclusion dispersion over 30 min. After the addition was complete, the reaction was continued at 10 °C for 2 h. After the reaction was completed, an ultrafiltration membrane with a molecular weight cutoff of 300,000 Da was used to replace the unreacted small molecule activator, byproducts, and free polysaccharides with deionized water. Separately, 0.08 g of ferric ammonium citrate was added to deionized water to form a 5 g ferric ammonium citrate solution. After stirring and dissolving, the solution was stirred at 10 min... Add the solution dropwise to the obtained dispersion and continue stirring for 20 min. Then, take 0.004 g of ferric chloride hexahydrate and add it to deionized water to form 5 g of the first iron source solution. After stirring and dissolving, add it dropwise to the above dispersion within 10 min and continue stirring for 10 min. Then, add sodium bicarbonate in three portions, with an interval of 5 min between each addition, to control the pH of the system to 6.3-6.6. Take another 0.014 g of ferric chloride hexahydrate and add it to deionized water to form 5 g of the second iron source solution. After stirring and dissolving, add it dropwise to the dispersion within 15 min, keeping the stirring speed at 400 r / min during the dropwise addition. After the dropwise addition is completed, continue stirring for 30 min to obtain the modified repellent active substance inclusion particle dispersion.

[0037] S4 formulation of bird repellent liquid preparation:

[0038] Add 4g of polysorbate 80, 1g of potassium sorbate and 10g of propylene glycol to the modified repellent active substance inclusion particle dispersion obtained in S3, stir at 300r / min for 30min, then add deionized water to make up to 1000g, continue stirring for 20min, filter through a 100-mesh sieve to obtain the bird repellent composition liquid formulation.

[0039] Example 2: A method for preparing a liquid formulation of a bird repellent composition, the specific steps of which are as follows:

[0040] Preparation of dodecenyl succinylated β-cyclodextrin using S1:

[0041] 47g of β-cyclodextrin was placed in a vacuum drying oven and dried at 58℃ for 5 hours. After cooling to room temperature, it was added to 560g of anhydrous dimethyl sulfoxide and stirred at 280r / min under nitrogen protection until completely dissolved. Subsequently, 6g of triethylamine and 0.7g of... 4-Dimethylaminopyridine was used, and the system temperature was controlled at 33℃. Separately, 2.6 g of dodecenyl succinic anhydride was added to 55 g of anhydrous dimethyl sulfoxide and stirred until transparent. This mixture was then added dropwise to a β-cyclodextrin solution over 25 min. After the addition was complete, the reaction was continued at 33℃ for 5 h. After the reaction was complete, the reaction solution was slowly poured into acetone to precipitate the precipitate. The precipitate was collected by centrifugation at 4800 r / min for 8 min, and then washed twice with acetone and once with ethanol. The precipitate was then redispersed in 450 g of 50% (v / v) ethanol aqueous solution, placed in a dialysis bag with a molecular weight cutoff of 500-1000 Da, and dialyzed against 50% (v / v) ethanol aqueous solution for 10 h, followed by dialyzed against deionized water for 10 h. Finally, the precipitate was vacuum dried at 38℃ for 10 h to obtain dodecenyl succinylated β-cyclodextrin.

[0042] S2 Preparation of Catecholized Carboxymethyl Chitosan:

[0043] 7.4 g of 2-morpholine ethanesulfonic acid was added to 760 g of deionized water, and sodium hydroxide was added to adjust the pH of the system to 5.8-6.0. The mixture was stirred until dissolved to obtain a 2-morpholine ethanesulfonic acid buffer solution. 9 g of carboxymethyl chitosan was added to the 2-morpholine ethanesulfonic acid buffer solution and stirred at 360 r / min for 1.5 h until completely dissolved. Nitrogen gas was then purged for 12 min to reduce the dissolved oxygen content. Subsequently, 1.3 g of dopamine hydrochloride was added, and the mixture was stirred for 10 min under light-protected conditions. Then, 1.7 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.9 g of [other chemicals] were added sequentially. N-hydroxysuccinimide was reacted at room temperature, in the dark, and under nitrogen protection for 10 h. After the reaction, the reaction solution was placed in a dialysis bag with a molecular weight cutoff of 8000-14000 Da, dialyzed with deionized water at pH 5.8-6.0 for 22 h, and then dialyzed with deionized water for 10 h. After freeze drying, catecholized carboxymethyl chitosan was obtained.

[0044] S3 Preparation of modified repellent active substance inclusion particle dispersion:

[0045] 42g of dodecenylsuccinylated β-cyclodextrin was added to 480g of deionized water, followed by 35g of anhydrous ethanol and 18g of propylene glycol. The mixture was stirred at 23℃ and 460r / min for 25min to obtain a modified cyclodextrin dispersion. Separately, 8g of the repellent active substance was added to 18g of anhydrous ethanol and stirred at 260r / min for 10min to obtain an ethanol solution of the repellent active substance. The temperature of the modified cyclodextrin dispersion was lowered to 6℃, and the ethanol solution of the repellent active substance was added dropwise to the modified cyclodextrin dispersion over 40min while stirring at 550r / min. After the addition was complete, stirring was continued for 3.5h to obtain an inclusion dispersion of the repellent active substance. The temperature of the obtained inclusion dispersion of the repellent active substance was controlled at 8℃, and 0.6g of... 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.33 g N-hydroxysuccinimide were stirred at 360 r / min for 15 min. Separately, 5 g of catecholized carboxymethyl chitosan was added to 100 g of deionized water and stirred until completely dispersed. This was then added dropwise to the activated repellent active substance inclusion dispersion over 25 min. After the addition was complete, the reaction was continued at 8 °C for 1.5 h. After the reaction, an ultrafiltration membrane with a molecular weight cutoff of 300,000 Da was used for ultrafiltration with deionized water to remove unreacted small molecule activators, byproducts, and free polysaccharides. Separately, 0.06 g of ferric ammonium citrate was added to deionized water to form a 5 g ferric ammonium citrate solution, which was stirred and dissolved before being stirred at 8 °C for 15 min. Add sodium bicarbonate dropwise to the obtained dispersion and continue stirring for 15 min. Then, take 0.003 g of ferric chloride hexahydrate and add it to deionized water to form 5 g of the first iron source solution. After stirring and dissolving, add it dropwise to the above dispersion within 8 min and continue stirring for 8 min. Then, add sodium bicarbonate in three portions, with an interval of 5 min between each addition, to control the pH of the system to 6.3-6.6. Separately, take 0.012 g of ferric chloride hexahydrate and add it to deionized water to form 5 g of the second iron source solution. After stirring and dissolving, add it dropwise to the dispersion within 12 min, keeping the stirring speed at 360 r / min during the dropwise addition. After the dropwise addition is completed, continue stirring for 25 min to obtain the modified repellent active substance inclusion particle dispersion.

[0046] S4 formulation of bird repellent liquid preparation:

[0047] Add 3.5g of polysorbate 80, 0.8g of potassium sorbate and 8g of propylene glycol to the modified repellent active substance inclusion particle dispersion obtained in S3, stir at 280r / min for 25min, then add deionized water to make up to 1000g, continue stirring for 15min, filter through a 100-mesh sieve to obtain the bird repellent composition liquid formulation.

[0048] Example 3: A method for preparing a liquid formulation of a bird repellent composition, the specific steps of which are as follows:

[0049] Preparation of dodecenyl succinylated β-cyclodextrin using S1:

[0050] 53g of β-cyclodextrin was placed in a vacuum drying oven and dried at 62℃ for 7 hours. After cooling to room temperature, it was added to 640g of anhydrous dimethyl sulfoxide and stirred at 320r / min under nitrogen protection until completely dissolved. Subsequently, 7g of triethylamine and 0.8g of... 4-Dimethylaminopyridine was used, and the system temperature was controlled at 37℃. Separately, 3.4 g of dodecenyl succinic anhydride was added to 65 g of anhydrous dimethyl sulfoxide and stirred until transparent. This mixture was then added dropwise to a β-cyclodextrin solution over 35 min. After the addition was complete, the reaction was continued at 37℃ for 7 h. After the reaction was complete, the reaction solution was slowly poured into acetone to precipitate the precipitate. The precipitate was collected by centrifugation at 5200 r / min for 12 min, and then washed twice with acetone and once with ethanol. The precipitate was then redispersed in 550 g of 50% (v / v) ethanol aqueous solution, placed in a dialysis bag with a molecular weight cutoff of 500-1000 Da, and dialyzed with 50% (v / v) ethanol aqueous solution for 14 h, followed by dialyzed with deionized water for 14 h. Finally, the solution was vacuum dried at 42℃ for 14 h to obtain dodecenyl succinylated β-cyclodextrin.

[0051] S2 Preparation of Catecholized Carboxymethyl Chitosan:

[0052] 8.2 g of 2-morpholine ethanesulfonic acid was added to 840 g of deionized water, and sodium hydroxide was added to adjust the pH of the system to 5.8-6.0. The mixture was stirred until dissolved to obtain a 2-morpholine ethanesulfonic acid buffer solution. 11 g of carboxymethyl chitosan was added to the 2-morpholine ethanesulfonic acid buffer solution and stirred at 440 r / min for 2.5 h until completely dissolved. Nitrogen gas was then purged for 18 min to reduce the dissolved oxygen content. Subsequently, 1.7 g of dopamine hydrochloride was added, and the mixture was stirred for 20 min under light-protected conditions. Then, 2.1 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 1.3 g of [other chemicals] were added sequentially. N-hydroxysuccinimide was reacted at room temperature, in the dark, and under nitrogen protection for 14 h. After the reaction, the reaction solution was placed in a dialysis bag with a molecular weight cutoff of 8000-14000 Da, dialyzed with deionized water at pH 5.8-6.0 for 26 h, and then dialyzed with deionized water for 14 h. After freeze drying, catecholized carboxymethyl chitosan was obtained.

[0053] S3 Preparation of modified repellent active substance inclusion particle dispersion:

[0054] 48g of dodecenylsuccinylated β-cyclodextrin was added to 520g of deionized water, followed by 45g of anhydrous ethanol and 22g of propylene glycol. The mixture was stirred at 540r / min for 35min at 27℃ to obtain a modified cyclodextrin dispersion. Separately, 10g of the repellent active ingredient was added to 22g of anhydrous ethanol and stirred at 340r / min for 20min to obtain an ethanol solution of the repellent active ingredient. The temperature of the modified cyclodextrin dispersion was lowered to 10℃, and the ethanol solution of the repellent active ingredient was added dropwise to the modified cyclodextrin dispersion over 50min while stirring at 650r / min. After the addition was complete, stirring was continued for 4.5h to obtain an inclusion dispersion of the repellent active ingredient. The temperature of the obtained inclusion dispersion was controlled at 12℃, and 0.7g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.42g of... N-hydroxysuccinimide was stirred at 440 rpm for 25 min. Separately, 7 g of catecholized carboxymethyl chitosan was added to 140 g of deionized water and stirred until completely dispersed. This was then added dropwise to the activated repellent active substance inclusion dispersion over 35 min. After the addition was complete, the reaction was continued at 12 °C for 2.5 h. After the reaction was complete, an ultrafiltration membrane with a molecular weight cutoff of 300,000 Da was used to replace the unreacted small molecule activator, byproducts, and free polysaccharides with deionized water. Separately, 0.1 g of ferric ammonium citrate was added to deionized water to form a 5 g ferric ammonium citrate solution. After stirring and dissolving, this solution was added dropwise to the resulting dispersion over 12 min. Stir for 25 min; then take 0.005 g of ferric chloride hexahydrate and add it to deionized water to form 5 g of the first iron source solution. After stirring and dissolving, add it dropwise to the above dispersion within 12 min. Continue stirring for 12 min, then add sodium bicarbonate in three portions, with an interval of 5 min between each addition, to control the pH of the system to 6.3-6.6; separately take 0.016 g of ferric chloride hexahydrate and add it to deionized water to form 5 g of the second iron source solution. After stirring and dissolving, add it dropwise to the dispersion within 18 min. During the dropwise addition, maintain the stirring speed at 440 r / min. After the dropwise addition is completed, continue stirring for 35 min to obtain the modified repellent active substance inclusion particle dispersion.

[0055] S4 formulation of bird repellent liquid preparation:

[0056] Add 4.5g of polysorbate 80, 1.2g of potassium sorbate and 12g of propylene glycol to the modified repellent active substance inclusion particle dispersion obtained in S3, stir at 320r / min for 35min, then add deionized water to make up to 1000g, continue stirring for 25min, filter through a 100-mesh sieve to obtain the bird repellent composition liquid formulation.

[0057] Comparative Example 1: The difference from Example 1 is that 45g of β-cyclodextrin was used instead of 45g of dodecenyl succinylated β-cyclodextrin in S3; the other conditions were the same as in Example 1.

[0058] Comparative Example 2: The difference from Example 1 is that 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide are not added in S3. Instead, 6g of catecholized carboxymethyl chitosan is added to 120g of deionized water and added to the inclusion dispersion of the repellent active substance obtained in S3 at the same dropping time and reaction time as in S4, so that the catecholized carboxymethyl chitosan exists only in a physical mixing manner; the other conditions are the same as in Example 1.

[0059] Comparative Example 3: The difference from Example 1 is that 6g of carboxymethyl chitosan was used in S3 instead of 6g of catecholized carboxymethyl chitosan, and the weight-average molecular weight, degree of carboxymethyl substitution, residual free amino content and moisture content of the carboxymethyl chitosan were the same as those of the carboxymethyl chitosan used in S2; the other conditions were the same as those in Example 1.

[0060] Comparative Example 4: The difference from Example 1 is that in S3, ferric ammonium citrate and ferric chloride hexahydrate were added together to deionized water, stirred and dissolved, and then added dropwise to the dispersion obtained in S4 within 20 minutes. After the addition was completed, sodium bicarbonate was added in three portions, and the pH of the system was controlled at 6.3-6.6. The other conditions were the same as in Example 1.

[0061] Comparative Example 5: The difference from Example 1 is that the step of adding ferric ammonium citrate is retained in S3, but after adding ferric ammonium citrate and stirring for 20 min, sodium bicarbonate is added directly in three portions to control the pH of the system to 6.3-6.6. Then, ferric chloride hexahydrate is added to deionized water, stirred and dissolved, and then added dropwise to the dispersion within 25 min; the other conditions are the same as in Example 1.

[0062] Comparative Example 6: The difference from Example 1 is that in S3, the low-temperature inclusion of the repellent active substance with dodecenyl succinylated β-cyclodextrin is not performed first. Instead, the repellent active substance, anhydrous ethanol and catecholized carboxymethyl chitosan are mixed and stirred for 45 min, and then the obtained dodecenyl succinylated β-cyclodextrin, deionized water, anhydrous ethanol and propylene glycol are added for dispersion; the other conditions are the same as in Example 1.

[0063] Performance testing

[0064] The bird-repellent compositions prepared in Examples 1-3 and Comparative Examples 1-6 were used as test samples. Three batches of each sample were prepared independently, with 100g of the original solution from each batch used for testing. Separately, each sample was diluted 80 times with deionized water as a diluent for application performance testing. For simulated surface spraying tests, a 100mm × 100mm clean glass slide, a 100mm × 100mm cement mortar board, and fresh corn leaves fixed to a polytetrafluoroethylene board were used as the substrate. A handheld pressure sprayer was used at a spray rate of 60mL / m². 2The dosage was applied evenly by spraying, and then dried for 2 hours at 25℃ and 60% relative humidity. For cage-rearing repellency testing, wheat grains were used as the test material, mixed with an 80-fold diluted solution at a mass ratio of 50:1, stirred for 1 minute, and then air-dried at 25℃ for 2 hours before use. For long-term bird deterrence testing in the field, direct-seeded rice plots with stable bird infestations and no interference from surrounding audio-visual bird deterrence equipment were selected. Three replicate plots were set up for each treatment, with each plot having an area of ​​20m². 2 A minimum 5m isolation zone should be set up between each residential area.

[0065] Dispersion uniformity test: Take the liquid formulations obtained in the examples and comparative examples, dilute them 100 times with deionized water, filter them through a 100-mesh sieve, place them at a constant temperature of 25°C for 10 minutes, and let them stand at 25°C for 2 hours. Observe whether there is a visible oil layer, precipitation, flocculation or stratification.

[0066] Thermal storage stability and dilution stability tests:

[0067] Thermal stability was tested according to GB / T 19136-2021. 100g of each sample was sealed in a glass bottle and placed at 54℃ for 14 days. After removal, the temperature was restored to 25℃, and the oil layer, sedimentation, and flocculation were observed. Dilution stability was tested according to GB / T1603-2025. 5mL of the liquid formulation was added to 95mL of standard hard water at 30℃. The mixture was inverted 10 times and allowed to stand for 2 hours. The oil layer, sedimentation, and flocculation were then observed.

[0068] Tests on effective component content, inclusion ratio, and release retention rate:

[0069] Cinnamaldehyde, eugenol and menthol were determined by gas chromatography according to GB / T 9722-2023; capsaicin and dihydrocapsaicin in capsicum oleoresin were determined by high performance liquid chromatography; when determining the total effective component content, the contents of cinnamaldehyde, eugenol, menthol, capsaicin and dihydrocapsaicin were determined separately, and the total amount of the five was taken as the total effective component of the compound repellent active substance.

[0070] When determining the inclusion rate, take 10g of liquid preparation and centrifuge at 10000r / min for 20min. Determine the content of free compound repellent active substances in the supernatant and the content of total compound repellent active substances after breaking the inclusion. The inclusion rate is calculated as (total effective component mass - free effective component mass) / total effective component mass × 100%.

[0071] When determining the release retention rate, spray an 80-fold diluted solution onto the surface of a glass slide and dry it for 2 hours. Place it in an environment of 25°C and 60% relative humidity for 14 days. Then, elute the residual active components with ethyl acetate. The release retention rate after 14 days is calculated as (mass of residual compound repellent active substance on the surface on the 14th day / mass of compound repellent active substance initially loaded on the surface) × 100%.

[0072] Test on retention rate of effective components after simulated rain:

[0073] Take an 80-fold dilution of the liquid formulations obtained in the examples and comparative examples, and spray them onto the surfaces of a glass slide, corn leaves, and cement mortar board, respectively, at a spraying rate of 60 mL / m². 2 After spraying, the samples were dried for 2 hours at 25℃ and 60% relative humidity. A simulated rainfall device was used for rinsing, with a rainfall intensity of 30 mm / h and a rainfall duration of 30 min. The nozzle was 500 mm away from the sample surface, and the water temperature was 25℃. After the rainfall, the samples were placed in an environment of 25℃ and 60% relative humidity for 2 hours. Then, 20 mL of ethyl acetate was used to elute the residual effective components on the sample surface, and the total retention of cinnamaldehyde, eugenol, menthol, capsaicin, and dihydrocapsaicin was determined. The retention rate of effective components after simulated rain was calculated as (residual effective components on the surface after rain / effective component loading on the surface before rain) × 100%.

[0074] Cage-rearing repellency activity test:

[0075] A cage-rearing experiment was conducted according to T / ZNX 019-2021. Artificially raised pigeons were used as the test subjects, with each pigeon weighing 280-360g. Six pigeons were placed in each treatment, and each pigeon was housed in a single cage. Pigeons were fasted for 24 hours before the experiment, but water was provided. Wheat grains, prepared according to the sample preparation method and air-dried, were used as the test material. 50g was placed in each cage. After 2 hours of feeding, the trays were removed, and the remaining wheat grains were weighed. Abnormal flight, lethargy, vomiting, or death were recorded during the feeding period. The blank control group used deionized water to treat the wheat grains in the same way. The refusal-to-feed rate was calculated as (average feed intake of the blank control group - average feed intake of the treatment group) / average feed intake of the blank control group multiplied by 100%.

[0076] 14-day field long-term bird deterrence rate test:

[0077] The effectiveness of bird repellency in field plots was evaluated according to T / ZNX 020-2021. Direct-seeded rice plots with stable bird damage were selected, and on the day of rice sowing, an 80-fold dilution of the liquid formulations obtained in the examples and comparative examples was applied as a spray at a rate of 60 mL / m². 2A control plot was sprayed with an equal volume of deionized water. On days 1, 7, and 14 after spraying, surveys were conducted during the two peak bird activity periods: 6:00-8:00 and 16:00-18:00 each day. Each plot was observed continuously for 30 minutes, recording the number of times birds entered, stayed, and pecked at food. Ten randomly selected 1-meter samples from each plot were also collected. 2 Number of affected plants within the quadrat. The 14-day long-term bird deterrent rate is calculated as (total number of bird stays and pecking in the blank control area - total number of bird stays and pecking in the treatment area) / total number of bird stays and pecking in the blank control area, multiplied by 100%.

[0078] Table 1. Stability performance test results

[0079] Dispersion uniformity thermal storage stability Dilution stability Example 1 No oil layer, no sediment, no flocculation No oil layer, no sediment, no flocculation No oil layer, no sediment, no flocculation Example 2 No oil layer, no sediment, no flocculation No oil layer, no sediment, no flocculation 7 No oil layer, no sediment, no flocculation 7 Example 3 No oil layer, no sediment, no flocculation No oil layer, no sediment, no flocculation No oil layer, no sediment, no flocculation Comparative Example 1 No oil layer, no sediment, no flocculation No oil layer, no sediment, no flocculation No oil layer, no sediment, no flocculation Comparative Example 2 Slight oil layer, no sediment Slight oil layer, no sediment Slight oil layer, no sediment Comparative Example 3 Small amount of flocculation, no oil layer Small amount of flocculation, no oil layer Small amount of flocculation, no oil layer Comparative Example 4 No oil layer, small amount of sediment No oil layer, small amount of sediment No oil layer, small amount of sediment Comparative Example 5 Small amount of flocculation, small amount of sedimentation Small amount of flocculation, small amount of sedimentation Small amount of flocculation, small amount of sedimentation Comparative Example 6 No oil layer, no sediment, slight flocculation No oil layer, no sediment, slight flocculation No oil layer, no sediment, slight flocculation

[0080] Table 2 Performance Test Results

[0081] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Encapsulation rate of repellent active substance (%) 84.7 82.3 85.1 83.5 78.6 83.8 84.1 82.6 84.4 14-day release retention rate (%) 57.8 52.1 59.3 56.4 34.8 42.6 45.8 43.9 50.6 Retention rate of effective components after simulated rain / glass slide (%) 73.4 68.5 72.0 70.6 39.6 55.3 49.2 58.8 63.7 Retention rate of effective components after simulated rain / maize leaves (%) 67.2 62.4 66.5 64.9 35.1 49.7 43.8 51.2 58.3 Cage feeding refusal to eat and avoidance (%) 86.5 83.2 87.1 88.0 772 82.9 82.1 80.4 84.0 Day 1 bird deterrence rate in the field (%) 91.4 88.6 91.8 92.1 80.5 86.3 85.4 84.7 88.8 Bird deterrence rate in the field on day 7 (%) 87.2 83.4 88.0 86.4 64.7 74.1 70.6 76.3 80.2 Bird deterrence rate in the field on day 14 (%) 82.6 78.8 83.5 82.0 51.8 63.7 59.8 66.9 72.5

[0082] Data Analysis: As shown in Tables 1 and 2, although Comparative Example 1, which uses unmodified β-cyclodextrin to replace dodecenyl succinylated β-cyclodextrin, still has a certain inclusion and initial repellency ability, the retention rate of effective components after rain, the release retention rate at fourteen days, and the bird repellency rate in the field at fourteen days are all lower than those of the Example. This indicates that ordinary β-cyclodextrin mainly relies on internal inclusion and is difficult to stabilize cinnamaldehyde, eugenol, menthol, and capsaicinoids in capsicum oleoresin at the same time. It also lacks an outer hydrophobic slow-release interface and carboxyl sites that can be grafted later. Compared to Comparative Example 1, the present invention first encapsulates the compound repellent active substance with dodecenyl succinylated β-cyclodextrin, then forms an adhesive shell on the outside of the encapsulated particles with catecholized carboxymethyl chitosan, and further employs ferric ammonium citrate pre-coordination, ferric chloride hexahydrate spot locking, and surface locking to make the volatilization and release of cinnamaldehyde, eugenol, and menthol more gradual, while ensuring that capsaicinoids still have good surface residue after rain. Comparative Example 2 only physically mixes catecholized carboxymethyl chitosan, Comparative Example 3 lacks catechol groups, Comparative Example 4 adds an iron source all at once, Comparative Example 5 omits low-level free trivalent iron spot locking, and Comparative Example 6 changes the order of encapsulation followed by grafting. None of these examples achieved the comprehensive effect of the present invention, indicating that the improvement of the present invention does not come from single encapsulation, single thickening, or single metal coordination, but from the synergistic effect formed by the continuous transfer of compound active substance encapsulation, adhesive shell, and layered coordination locking.

[0083] The liquid formulation obtained by this invention can simultaneously exert odor repellency, taste irritation repellency, and long-lasting residual effects after rain. It is suitable for open environments such as orchards, grain drying yards, grain warehouse perimeters, and airport lawns. It can reduce the need for frequent re-spraying, reduce the risk of odor overload and surface contamination caused by the initial burst release of plant-derived active substances, and improve the sustainability of bird repellency treatment and the convenience of on-site use.

[0084] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.

Claims

1. A method for preparing a liquid formulation of a bird-repelling composition, characterized in that, Includes the following steps: (1) Preparation of dodecenyl succinylated β-cyclodextrin: β-cyclodextrin was dissolved in anhydrous dimethyl sulfoxide and reacted with dodecenyl succinic anhydride in the presence of triethylamine and 4-dimethylaminopyridine to obtain dodecenyl succinylated β-cyclodextrin. (2) Preparation of catecholized carboxymethyl chitosan: Carboxymethyl chitosan was dissolved in 2-morpholine ethanesulfonic acid buffer, dopamine hydrochloride was added, and the mixture was reacted in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide to obtain catecholized carboxymethyl chitosan. (3) Preparation of modified repellent active substance inclusion dispersion: The dodecenyl succinylated β-cyclodextrin is dispersed in an aqueous system to obtain a modified cyclodextrin dispersion; the repellent active substance is dissolved in ethanol to obtain a repellent active substance ethanol solution, and the repellent active substance ethanol solution is added dropwise to the modified cyclodextrin dispersion to obtain a repellent active substance inclusion dispersion; 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide are added to the repellent active substance inclusion dispersion for activation, and then catecholized carboxymethyl chitosan, ferric ammonium citrate solution, first iron source solution and second iron source solution are added in sequence to obtain a modified repellent active substance inclusion particle dispersion; (4) Preparation of bird repellent liquid formulation: Add surfactant, preservative and solubilizer to the modified repellent active substance inclusion particle dispersion, and add deionized water to make up the difference to obtain bird repellent liquid formulation; By weight, the amounts of dodecenyl succinylated β-cyclodextrin, repellent active substance, catecholized carboxymethyl chitosan, ferric ammonium citrate solution, first iron source solution and second iron source solution in step (3) are 42-48 parts, 8-10 parts, 5-7 parts, 5 parts, 5 parts and 5 parts respectively. Both the first iron source solution and the second iron source solution are aqueous solutions of ferric chloride hexahydrate.

2. The preparation method according to claim 1, characterized in that, By weight, the dodecenyl succinylated β-cyclodextrin in step (1) is prepared from 47-53 parts of β-cyclodextrin and 2.6-3.4 parts of dodecenyl succinic anhydride; the amount of triethylamine is 6-7 parts and the amount of 4-dimethylaminopyridine is 0.7-0.8 parts.

3. The preparation method according to claim 1, characterized in that, By weight, the catecholized carboxymethyl chitosan in step (2) is prepared from 9-11 parts of carboxymethyl chitosan and 1.3-1.7 parts of dopamine hydrochloride; the amount of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride is 1.7-2.1 parts and the amount of N-hydroxysuccinimide is 0.9-1.3 parts.

4. The preparation method according to claim 1, characterized in that, Based on a weight of 5 parts, the iron ammonium citrate solution in step (3) contains 0.06-0.1 parts of iron ammonium citrate, and the remainder is deionized water.

5. The preparation method according to claim 1, characterized in that, Based on a weight of 5 parts, the content of ferric chloride hexahydrate in the first iron source solution in step (3) is 0.003-0.005 parts, and the rest is deionized water.

6. The preparation method according to claim 1, characterized in that, Based on a weight of 5 parts, the content of ferric chloride hexahydrate in the second iron source solution in step (3) is 0.012-0.016 parts, and the rest is deionized water.

7. The preparation method according to claim 1, characterized in that, By weight, the repellent active substance in step (4) includes 5 parts cinnamaldehyde, 2.5 parts capsicum oleoresin, 1 part eugenol, and 0.5 parts menthol.

8. The preparation method according to claim 1, characterized in that, The surfactant mentioned in step (4) is one of alkyl glycoside, Tween, and polysorbate; the preservative is one of potassium sorbate, sodium benzoate, and sodium dehydroacetate.

9. The preparation method according to claim 1, characterized in that, The cosolvent mentioned in step (4) is one of propylene glycol, glycerin, and polyethylene glycol.

10. A liquid formulation of a bird-repelling composition, characterized in that, The bird repellent composition liquid formulation prepared according to any one of claims 1-9 comprises modified repellent active substance inclusion particles, wherein the modified repellent active substance inclusion particles comprise, from the inside out, a repellent active substance inclusion core layer, a dodecenyl succinylated β-cyclodextrin inclusion layer, a catecholized carboxymethyl chitosan outer layer, and an iron-catechin coordination locking layer.