A novel high-efficiency bactericide and its preparation method

Abstract

This invention relates to a novel, highly efficient bactericide and its preparation method, belonging to the field of antibacterial materials technology. The invention utilizes the reaction of epoxy groups and tertiary amine compounds in maleic pine carboxylic acid glyceride under hydrochloric acid to convert the epoxy groups into a hydroxyl quaternary ammonium salt structure. Then, an esterification reaction between trimellitic anhydride acyl chloride and hydroxyl groups is used to introduce an anhydride group into the molecular chain. Finally, an esterification reaction between anhydride and hydroxyl groups is used to introduce quaternary phosphonium salt and silver citrate structures into the molecular chain, resulting in a novel, highly efficient bactericide. The novel, highly efficient bactericide prepared by this invention simultaneously contains quaternary ammonium salt, quaternary phosphonium salt, and metallic silver ions. The positively charged quaternary ammonium salt and quaternary phosphonium salt are adsorbed onto the negatively charged bacterial surface through electrostatic interactions, exerting antibacterial and bacteriostatic effects by altering membrane permeability. The silver ions in silver citrate can bind to the sulfhydryl and carboxyl groups of bacterial membrane proteins, disrupting membrane integrity and thus exerting antibacterial and bacteriostatic effects.

Description

Technical Field

[0001] This invention relates to a novel, highly efficient bactericide and its preparation method, belonging to the field of antibacterial materials technology. Background Technology

[0002] Water is an essential resource for human survival. Currently, the contradiction between the ever-increasing water consumption and the severe water shortage is becoming increasingly acute. Water treatment antibacterial agents are an important means of preventing pollution, protecting the environment, and reclaiming water resources. However, traditional water treatment antibacterial agents such as chlorine, ozone, hydrogen peroxide, and peroxides all have various drawbacks: poor chemical stability; high toxicity harmful to human health; easy reaction with organic matter to form carcinogenic compounds; low antibacterial activity; and environmental pollution, etc.

[0003] Antimicrobial agents are numerous and diverse, exhibiting significant differences in their sources, structures, and antimicrobial mechanisms. Among them, quaternary ammonium compounds, in addition to possessing the basic properties of surfactants such as surface adsorption, surface tension reduction, and aggregation in solution, also exhibit biological effects such as inhibiting and killing microorganisms. Therefore, in the early stages of their development, these surfactants were primarily used as bactericides. The bactericidal mechanism of quaternary ammonium bactericides mainly involves the adsorption of positively charged head groups onto the negatively charged bacterial surface, altering the permeability of the bacterial cell wall. Furthermore, after adsorption onto the bacterial surface, their hydrophobic and hydrophilic groups penetrate deeply into the lipid and protein layers of the bacterial cell, respectively, leading to enzyme inactivation and protein denaturation.

[0004] Rosin is an inexpensive, abundant, and renewable natural resource. To endow it with antibacterial activity, rosin-based quaternary ammonium salt compounds have been developed. However, these rosin-based quaternary ammonium salts have poor antibacterial effects and narrow antibacterial spectrum, resulting in unsatisfactory practical applications. Summary of the Invention

[0005] The purpose of this invention is to provide a novel and highly efficient bactericide and its preparation method, so as to solve the problem of the poor antibacterial effect of current rosin-based quaternary ammonium salts.

[0006] This invention provides a method for preparing a novel, highly efficient bactericide, comprising the following steps: reacting a maleic anhydride quaternary ammonium hydrochloride compound with (2-hydroxyethyl)triphenylphosphonium chloride and silver citrate sequentially in a solvent at 95-105°C to obtain the novel, highly efficient bactericide; the molar ratio of the maleic anhydride quaternary ammonium hydrochloride compound, (2-hydroxyethyl)triphenylphosphonium chloride, and silver citrate is 1:1:2 or 1:2:1; the chemical structure of the maleic anhydride quaternary ammonium hydrochloride compound is as follows: ; Wherein, R is a C8~C12 alkyl group.

[0007] Preferably, the method of the mixed reaction is as follows: the maleic pine carboxylic acid quaternary ammonium hydrochloric anhydride compound and solvent are mixed, (2-hydroxyethyl)triphenylphosphonium chloride is added, and the mixture is stirred at 95~105℃ for 4~5h, then silver citrate is added, and the mixture is stirred for another 3~4h.

[0008] Preferably, after the mixing reaction is completed, the system after the mixing reaction is distilled under reduced pressure to remove the solvent, and then dried to obtain a novel high-efficiency bactericide.

[0009] Preferably, the preparation method of the maleic pine carboxylic acid quaternary ammonium hydrochloric anhydride compound is as follows: (1) After mixing maleic anhydride glycerol and a monotertiary amine compound in a solvent, hydrochloric acid was added, and the mixture was heated to 80-82°C and stirred under reflux for 48-50 h to obtain maleic anhydride quaternary ammonium salt compound; the molar ratio of nitrogen in the monotertiary amine compound to the molar ratio of epoxy groups in maleic anhydride glycerol was 1.05-1.1:1; the chemical structure of the maleic anhydride glycerol is as follows: ; (2) After reacting trimellitic anhydride acyl chloride and pyridine in a solvent, add maleic anhydride quaternary ammonium salt compound and continue to react to obtain maleic anhydride quaternary ammonium salt compound; the mass ratio of trimellitic anhydride acyl chloride to pyridine is 63.2:28~31, and the molar amount of hydroxyl group in maleic anhydride quaternary ammonium salt compound is equal to the molar amount of trimellitic anhydride acyl chloride.

[0010] Preferably, the monomethyl tertiary amine compound is N,N-dimethyl-n-octylamine, N,N-dimethyl-n-nonylamine, N,N-dimethyl-n-decylamine, undecyldimethyl tertiary amine, or dodecyldimethyl tertiary amine.

[0011] Preferably, the molar ratio of HCl in the hydrochloric acid to the molar ratio of epoxy groups in the maleic anhydride glyceride is 1.2~1.3:1.

[0012] Preferably, after stirring and refluxing for 48-50 hours, the solvent is removed by vacuum distillation of the system after stirring and refluxing to obtain a crude product. The crude product and methyl isobutyl ketone are mixed at a mass ratio of 1:1.8 at 60°C and then cooled to 15°C. The mixture is filtered, and the filtered solid is dried to obtain the maleic anhydride carboxylic acid quaternary ammonium salt compound.

[0013] Preferably, the temperature for mixing trimellitic anhydride acyl chloride and pyridine in a solvent is 5-8°C, and the reaction time is 30-45 min.

[0014] Preferably, the temperature for the continued mixing reaction is 80~85℃, and the time is 2~3h.

[0015] The present invention also provides a novel high-efficiency bactericide prepared by the method described above.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention utilizes the reaction of epoxy groups and tertiary amine compounds in maleic pine carboxylic acid glyceride under the action of hydrochloric acid to convert epoxy groups into hydroxy quaternary ammonium salt structures. Then, the anhydride group is introduced into the molecular chain by the esterification reaction between trimellitic anhydride acyl chloride and hydroxyl groups. Finally, the quaternary phosphonium salt and silver citrate structures are introduced into the molecular chain by the esterification reaction between anhydride and hydroxyl groups, thus obtaining a novel and highly efficient bactericide. The novel, highly efficient bactericide prepared in this invention contains quaternary ammonium salt, quaternary phosphorus salt, and metallic silver ions. The positively charged quaternary ammonium salt is adsorbed onto the negatively charged bacterial surface through electrostatic interaction. The hydrophobic alkyl chain inserts into the lipid layer of the cell membrane, altering membrane permeability and causing leakage of small molecules (such as potassium ions) from the bacterial cell, disrupting the cell's osmotic pressure balance and leading to irreversible bacterial death. Quaternary phosphorus salt has similar effects to quaternary ammonium salt, but the phosphorus atom in quaternary phosphorus salt has a larger radius and lower polarity than the nitrogen atom in quaternary ammonium salt, resulting in stronger hydrophobicity and easier insertion into the deeper layers of the cell membrane. It has a unique penetrating ability against Bacillus subtilis spores, destroying the cortical structure and inhibiting germination. The silver ions in silver citrate can bind to the sulfhydryl and carboxyl groups of bacterial membrane proteins, disrupting membrane integrity and thus exerting antibacterial and bacteriostatic effects. Attached Figure Description

[0017] Figure 1 The 1H NMR spectrum of the quaternary ammonium salt compound of maleic pine carboxylate prepared in Example 1 of this invention; Figure 2 The image shows the 1H NMR spectrum of the maleic anhydride compound prepared in Example 1 of this invention. Detailed Implementation

[0018] The following examples are intended to further illustrate the content of the present invention, rather than to limit the scope of protection of the present invention.

[0019] Specific embodiments of the high-efficiency industrial water treatment cleaning agent and its preparation method of the present invention are as follows: Example 1

[0020] The preparation method of the novel high-efficiency bactericide in this embodiment includes the following steps: (1) Take 100g of maleic anhydride and 190g of epichlorohydrin and add them to a three-necked flask equipped with a stirrer, condenser and thermometer. Heat to 75°C and stir until the maleic anhydride dissolves. Then add 4g of tetrabutylammonium bromide catalyst and stir at 95°C for 7h to obtain maleic anhydride chlorohydrin intermediate. Reduce the temperature of the material in the three-necked flask to 70°C, add 31g of sodium hydroxide and continue stirring at 70°C for 3h. After the reaction is completed, cool to room temperature, filter to remove the generated sodium chloride, wash the filtrate with water until neutral, and distill under reduced pressure to remove water and excess epichlorohydrin to obtain yellow transparent maleic anhydride glycerol ester (epoxy value 0.502mol / 100g). The chemical structure of maleic anhydride is as follows: ; The chemical structure of glyceryl maleic acid is as follows: .

[0021] (2) Add 58.7g of maleic anhydride glycerol, a tertiary amine compound (the molar ratio of nitrogen in the tertiary amine compound to the molar ratio of epoxy groups in maleic anhydride glycerol) and 300mL of anhydrous ethanol to a three-necked flask. After stirring evenly, add 35% concentrated hydrochloric acid (the molar ratio of HCl in the concentrated hydrochloric acid to the molar ratio of epoxy groups in maleic anhydride glycerol) dropwise to the three-necked flask. After the addition is complete, heat to 80℃ and stir under reflux to react. After 48 hours of reaction, the solvent was removed by vacuum distillation to obtain the crude product. The crude product and methyl isobutyl ketone were heated to 60°C at a mass ratio of 1:1.8 and stirred until the crude product was fully dissolved. Then, the mixture was cooled to 15°C, and a solid precipitated. The solid was immediately filtered and dried in a vacuum drying oven at 50°C for 24 hours to obtain the maleic anhydride quaternary ammonium salt compound. The tertiary amine compound in this example was N,N-dimethyl-n-octylamine. The 1H NMR spectrum of the prepared maleic anhydride quaternary ammonium salt compound is shown below. Figure 1 As shown, the chemical structure is as follows: ; Where R is octyl.

[0022] (3) Add 63.2 g of trimellitic anhydride acyl chloride and 280 mL of solvent benzene to a three-necked flask equipped with a reflux condenser, a dropping funnel, and a stirring device. Place the three-necked flask in a water bath and control the temperature of the material in the three-necked flask to 5 °C. Add 28 g of anhydrous pyridine to the three-necked flask. After the addition is complete, stir for 30 min. At room temperature, add a 40% (w / w) anhydrous dioxane solution of maleic anhydride quaternary ammonium salt compound (the molar amount of hydroxyl groups in the maleic anhydride quaternary ammonium salt compound is equal to the molar amount of trimellitic anhydride acyl chloride) to the three-necked flask. After the addition is complete, heat to 80 °C and stir under reflux for 3 h. Filter the reaction solution and then distill the filtrate under reduced pressure to remove the solvent benzene, dioxane, and excess pyridine. Finally, dry in a vacuum drying oven at 50 °C for 24 h to obtain the maleic anhydride quaternary ammonium hydrochloride compound. The 1H NMR spectrum of the maleic anhydride quaternary ammonium hydrochloride compound is shown below. Figure 2 As shown, the chemical structure is as follows: ; Where R is octyl.

[0023] (4) Add 20g of maleic anhydride quaternary ammonium hydrochloride compound and 100mL of anhydrous butyl acetate to a three-necked flask equipped with a reflux condenser and a stirrer. Stir until the maleic anhydride quaternary ammonium hydrochloride compound is fully dissolved. Then add (2-hydroxyethyl)triphenylphosphonium chloride to the three-necked flask, heat to 95℃, stir and react for 5h, then add silver citrate, continue stirring and react for 3h, cool to 50℃, and distill off the solvent butyl acetate under reduced pressure. Finally, dry in a vacuum drying oven at 50℃ for 24h to obtain a new type of high-efficiency bactericide. The molar ratio of (2-hydroxyethyl)triphenylphosphonium chloride, silver citrate and maleic anhydride quaternary ammonium hydrochloride compound is 2:1:1. Example 2

[0024] The preparation method of the novel high-efficiency bactericide in this embodiment includes the following steps: (1) Take 100g of maleic anhydride and 190g of epichlorohydrin and add them to a three-necked flask equipped with a stirrer, condenser and thermometer. Heat to 75°C and stir until the maleic anhydride dissolves. Then add 4g of tetrabutylammonium bromide catalyst and stir at 95°C for 7h to obtain maleic anhydride chlorohydrin intermediate. Reduce the temperature of the material in the three-necked flask to 70°C, add 31g of sodium hydroxide and continue stirring at 70°C for 3h. After the reaction is completed, cool to room temperature, filter to remove the generated sodium chloride, wash the filtrate with water until neutral, and distill under reduced pressure to remove water and excess epichlorohydrin to obtain yellow transparent maleic anhydride glycerol ester (epoxy value 0.502mol / 100g). The chemical structure of maleic anhydride is as follows: ; The chemical structure of glyceryl maleic acid is as follows: .

[0025] (2) Add 58.7g of maleic anhydride glycerol, a tertiary amine compound (the molar ratio of nitrogen in the tertiary amine compound to the molar ratio of epoxy groups in maleic anhydride glycerol) and 300mL of anhydrous ethanol to a three-necked flask. After stirring evenly, add 35% concentrated hydrochloric acid (the molar ratio of HCl in the concentrated hydrochloric acid to the molar ratio of epoxy groups in maleic anhydride glycerol) dropwise to the three-necked flask. After the addition is complete, heat to 80℃ and stir under reflux to react. After 48 hours of reaction, the solvent was removed by vacuum distillation to obtain a crude product. The crude product and methyl isobutyl ketone were heated to 60°C at a mass ratio of 1:1.8 and stirred until the crude product was fully dissolved. Then, the mixture was cooled to 15°C, and a solid precipitated. The solid was immediately filtered and dried in a vacuum drying oven at 50°C for 24 hours to obtain the maleic anhydride quaternary ammonium salt compound. The tertiary amine compound in this example was dodecyl dimethyl tertiary amine. The chemical structure of the prepared maleic anhydride quaternary ammonium salt compound is as follows: ; Wherein, R is dodecyl.

[0026] (3) Add 63.2 g of trimellitic anhydride acyl chloride and 280 mL of solvent benzene to a three-necked flask equipped with a reflux condenser, a dropping funnel, and a stirring device. Place the three-necked flask in a water bath and control the temperature of the material in the three-necked flask to 5 °C. Add 28 g of anhydrous pyridine to the three-necked flask. After the addition is complete, stir for 30 min. At room temperature, add a 40% (w / w) anhydrous dioxane solution of maleic anhydride quaternary ammonium salt compound (the molar amount of hydroxyl groups in the maleic anhydride quaternary ammonium salt compound is equal to the molar amount of trimellitic anhydride acyl chloride) to the three-necked flask. After the addition is complete, heat to 80 °C and stir under reflux for 3 h. Filter the reaction solution and then distill the filtrate under reduced pressure to remove the solvent benzene, dioxane, and excess pyridine. Finally, dry in a vacuum drying oven at 50 °C for 24 h to obtain the maleic anhydride quaternary ammonium hydrochloride compound. The chemical structure of the maleic anhydride quaternary ammonium hydrochloride compound is as follows: ; Wherein, R is dodecyl.

[0027] (4) Add 20g of maleic anhydride quaternary ammonium hydrochloride compound and 100mL of anhydrous butyl acetate to a three-necked flask equipped with a reflux condenser and a stirrer. Stir until the maleic anhydride quaternary ammonium hydrochloride compound is fully dissolved. Then add (2-hydroxyethyl)triphenylphosphonium chloride to the three-necked flask, heat to 95℃, stir and react for 5h, then add silver citrate, continue stirring and react for 3h, cool to 50℃, and distill off the solvent butyl acetate under reduced pressure. Finally, dry in a vacuum drying oven at 50℃ for 24h to obtain a new type of high-efficiency bactericide. The molar ratio of (2-hydroxyethyl)triphenylphosphonium chloride, silver citrate and maleic anhydride quaternary ammonium hydrochloride compound is 2:1:1. Example 3

[0028] The preparation method of the novel high-efficiency bactericide in this embodiment includes the following steps: (1) Take 100g of maleic anhydride and 190g of epichlorohydrin and add them to a three-necked flask equipped with a stirrer, condenser and thermometer. Heat to 75°C and stir until the maleic anhydride dissolves. Then add 4g of tetrabutylammonium bromide catalyst and stir at 95°C for 7h to obtain maleic anhydride chlorohydrin intermediate. Reduce the temperature of the material in the three-necked flask to 70°C, add 31g of sodium hydroxide and continue stirring at 70°C for 3h. After the reaction is completed, cool to room temperature, filter to remove the generated sodium chloride, wash the filtrate with water until neutral, and distill under reduced pressure to remove water and excess epichlorohydrin to obtain yellow transparent maleic anhydride glycerol ester (epoxy value 0.502mol / 100g). The chemical structure of maleic anhydride is as follows: ; The chemical structure of glyceryl maleic acid is as follows: .

[0029] (2) Add 58.7g of maleic anhydride glycerol, a tertiary amine compound (the molar ratio of nitrogen in the tertiary amine compound to the molar ratio of epoxy groups in maleic anhydride glycerol) and 300mL of anhydrous ethanol to a three-necked flask. After stirring evenly, add 35% concentrated hydrochloric acid (the molar ratio of HCl in the concentrated hydrochloric acid to the molar ratio of epoxy groups in maleic anhydride glycerol) dropwise to the three-necked flask. After the addition is complete, heat to 80℃ and stir under reflux to react. After 48 hours of reaction, the solvent was removed by vacuum distillation to obtain a crude product. The crude product and methyl isobutyl ketone were heated to 60°C at a mass ratio of 1:1.8 and stirred until the crude product was fully dissolved. Then, the mixture was cooled to 15°C, and a solid precipitated. The solid was immediately filtered and dried in a vacuum drying oven at 50°C for 24 hours to obtain the maleic anhydride quaternary ammonium salt compound. The tertiary amine compound in this example is N,N-dimethyl-n-octylamine. The chemical structure of the prepared maleic anhydride quaternary ammonium salt compound is as follows: ; Where R is octyl.

[0030] (3) Add 63.2 g of trimellitic anhydride acyl chloride and 280 mL of solvent benzene to a three-necked flask equipped with a reflux condenser, a dropping funnel, and a stirring device. Place the three-necked flask in a water bath and control the temperature of the material in the three-necked flask to 5 °C. Add 28 g of anhydrous pyridine to the three-necked flask. After the addition is complete, stir for 30 min. At room temperature, add a 40% (w / w) anhydrous dioxane solution of maleic anhydride quaternary ammonium salt compound (the molar amount of hydroxyl groups in the maleic anhydride quaternary ammonium salt compound is equal to the molar amount of trimellitic anhydride acyl chloride) to the three-necked flask. After the addition is complete, heat to 80 °C and stir under reflux for 3 h. Filter the reaction solution and then distill the filtrate under reduced pressure to remove the solvent benzene, dioxane, and excess pyridine. Finally, dry in a vacuum drying oven at 50 °C for 24 h to obtain the maleic anhydride quaternary ammonium hydrochloride compound. The chemical structure of the maleic anhydride quaternary ammonium hydrochloride compound is as follows: ; Where R is octyl.

[0031] (4) Add 20g of maleic anhydride quaternary ammonium hydrochloride compound and 100mL of anhydrous butyl acetate to a three-necked flask equipped with a reflux condenser and a stirrer. Stir until the maleic anhydride quaternary ammonium hydrochloride compound is fully dissolved. Then add (2-hydroxyethyl)triphenylphosphonium chloride to the three-necked flask, heat to 95℃, stir and react for 4h, then add silver citrate, continue stirring and react for 4h, cool to 50℃, and distill off the solvent butyl acetate under reduced pressure. Finally, place in a vacuum drying oven at 50℃ and dry for 24h to obtain a new type of high-efficiency bactericide. The molar ratio of (2-hydroxyethyl)triphenylphosphonium chloride, silver citrate and maleic anhydride quaternary ammonium hydrochloride compound is 1:2:1.

[0032] Comparative Example 1 The difference between the preparation method of the novel high-efficiency bactericide in this comparative example and the preparation method of the novel high-efficiency bactericide in Example 1 is that the tertiary amine compound in step (2) of the preparation method of the novel high-efficiency bactericide in this comparative example is N,N-dimethylpropylamine.

[0033] Comparative Example 2 The difference between the preparation method of the novel high-efficiency bactericide in this comparative example and the preparation method of the novel high-efficiency bactericide in Example 1 is that the tertiary amine compound in step (2) of the preparation method of the novel high-efficiency bactericide in this comparative example is hexadecyl dimethyl tertiary amine.

[0034] Comparative Example 3 The difference between the preparation method of the novel high-efficiency bactericide in this comparative example and the preparation method of the novel high-efficiency bactericide in Example 1 is that the amount of (2-hydroxyethyl)triphenylphosphonium chloride in step (4) of the preparation method of the novel high-efficiency bactericide in this comparative example is 0, and the molar ratio of silver citrate and maleic anhydride carboxylic acid quaternary ammonium hydrochloric acid compound is 3:1.

[0035] Comparative Example 4 The difference between the preparation method of the novel high-efficiency bactericide in this comparative example and the preparation method of the novel high-efficiency bactericide in Example 1 is that the amount of silver citrate used in step (4) of the preparation method of the novel high-efficiency bactericide in this comparative example is 0, and the molar ratio of (2-hydroxyethyl)triphenylphosphonium chloride and maleic pine carboxylic acid quaternary ammonium hydrochloric anhydride compound is 3:1.

[0036] Comparative Example 5 The difference between the preparation method of the novel high-efficiency bactericide in this comparative example and the preparation method of the novel high-efficiency bactericide in Example 1 is that the preparation method of the novel high-efficiency bactericide in this comparative example is as follows: the novel high-efficiency bactericide prepared in Comparative Example 3 and the novel high-efficiency bactericide prepared in Comparative Example 4 are stirred evenly at a mass ratio of 1:1 to obtain the bactericide.

[0037] Comparative Example 6 The difference between the preparation method of the novel high-efficiency bactericide in this comparative example and the preparation method of the novel high-efficiency bactericide in Example 1 is that step (4) of the preparation method of the novel high-efficiency bactericide in this comparative example is as follows: stir the maleic pine carboxylic acid quaternary ammonium hydrochloric anhydride compound, (2-hydroxyethyl) triphenylphosphonium chloride and silver citrate evenly to obtain the novel high-efficiency bactericide; wherein, the molar ratio of (2-hydroxyethyl) triphenylphosphonium chloride, silver citrate and maleic pine carboxylic acid quaternary ammonium hydrochloric anhydride compound is 2:1:1.

[0038] Experimental Example This experimental example is used to evaluate the antibacterial and bacteriostatic effects of the bactericides prepared in each embodiment and comparative example. The test and evaluation method is as follows: The bactericide is dispersed and dissolved in sterile water to obtain a bactericide solution, and then a concentration of 10 is transferred using a pipette. 7 Add a CFU / mL bacterial suspension (containing Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 6538, or Bacillus subtilis ATCC 6633) to a sterilized shaking tube. Then, transfer an equal volume of bactericide solution to the shaking tube to achieve a bactericide concentration of 100 mg / L and a bacterial concentration of 5 × 10⁻⁶. 6 CFU / mL, the opening of the shake tubes was sealed with a breathable sealing film. A shake tube containing sterile water instead of the bactericide solution served as a control. Both the experimental group shake tubes (containing bactericide solution) and the control group shake tubes (containing sterile water) were placed in a water bath with constant temperature shaking and incubated at 37℃ for 24 hours. Then, 200 μL of liquid was transferred from either the experimental or control shake tubes into the culture medium using a pipette, and then placed in a biochemical incubator and incubated at 37℃ for 24 hours. The number of colonies grown on the culture medium was counted. The antibacterial rate was calculated based on the number of colonies (A) growing on the culture medium corresponding to the liquid transferred from the experimental group shake tube and the number of colonies (B) growing on the culture medium corresponding to the liquid transferred from the control group shake tube. The antibacterial rate was calculated as (A) / B × 100%. Each sample was tested three times, and the average of the three results was taken as the final experimental result. The antibacterial rate test results of the bactericides prepared in each embodiment and comparative example are shown in Table 1.

[0039] Table 1. Antibacterial rates of the bactericides prepared in each example and comparative example.

[0040] As shown in the test results in Table 1, the novel high-efficiency bactericide prepared in this invention has an antibacterial rate of more than 98% against Escherichia coli, Staphylococcus aureus and Bacillus subtilis, and has good antibacterial and bacteriostatic effects. The reason can be attributed to the following: The novel high-efficiency bactericide prepared in this invention contains quaternary ammonium salt, quaternary phosphonium salt, and metallic silver ions. The positively charged quaternary ammonium salt is adsorbed onto the negatively charged bacterial surface through electrostatic interaction. The hydrophobic alkyl chain inserts into the lipid layer of the cell membrane, causing leakage of small molecules (such as potassium ions) within the bacterial cell by altering membrane permeability, thus disrupting the cell's osmotic pressure balance and leading to irreversible bacterial death. Quaternary phosphonium salt and quaternary ammonium salt have similar effects, but the phosphorus atom in quaternary phosphonium salt has a larger radius and lower polarity than the nitrogen atom in quaternary ammonium salt, resulting in stronger hydrophobicity and easier insertion into the deeper layers of the cell membrane. It has a unique penetrating ability against Bacillus subtilis spores, destroying the cortical structure and inhibiting germination. The silver ions in silver citrate can bind to the sulfhydryl and carboxyl groups of bacterial membrane proteins, disrupting membrane integrity and thus exerting antibacterial and bacteriostatic effects.

[0041] Compared to Example 1, the antibacterial agents prepared using N,N-dimethylpropylamine or hexadecyldimethyl tertiary amine as tertiary amine compounds in Comparative Examples 1 and 2 showed a decrease in antibacterial rates against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. This indicates that both excessively long and excessively short alkyl chains in quaternary ammonium salts are detrimental to antibacterial activity. When the alkyl chain is too long, the resistance to penetration of the bacterial cell membrane by the quaternary ammonium salt is too high, which is not conducive to the exertion of antibacterial activity. When the alkyl chain is too short, the hydrophobicity is low, and the affinity with the lipid layer of the bacterial cell membrane is poor, which is also not conducive to improving antibacterial activity.

[0042] Compared to Example 1, the antibacterial agents prepared in Comparative Examples 3-5 lacked the silver citrate and quaternary phosphonium salt structures, resulting in poorer antibacterial effects. This indicates that the quaternary phosphonium salt and silver citrate structures in the antibacterial agents can exert a synergistic effect. The two structures work together to improve the antibacterial and bacteriostatic effects against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis through hydrophobic interactions and chemical binding, respectively.

[0043] Compared to Example 1, Comparative Example 6 used a physical mixture of maleic anhydride carboxylic acid quaternary ammonium hydrochloride, (2-hydroxyethyl)triphenylphosphonium chloride, and silver citrate. These three compounds were not chemically bonded together; they were essentially a mixture of quaternary ammonium salt, quaternary phosphonium salt, and silver citrate. The antibacterial effect of this mixture was different, indicating that the antibacterial effect would be significantly improved when the three groups were chemically bonded together. This may be because the quaternary ammonium salt, quaternary phosphonium salt, and silver citrate are more evenly dispersed in the antibacterial agent prepared by chemical bonding, and the three groups are closer together, thus exerting a better antibacterial effect.

Claims

1. A method for preparing a novel, highly efficient bactericide, characterized in that, Includes the following steps: A novel, highly effective bactericide was obtained by reacting a maleic anhydride quaternary ammonium hydrochloride compound with (2-hydroxyethyl)triphenylphosphonium chloride and silver citrate in a solvent at 95-105°C. The molar ratio of the maleic anhydride quaternary ammonium hydrochloride compound, (2-hydroxyethyl)triphenylphosphonium chloride, and silver citrate was 1:1:2 or 1:2:

1. The chemical structure of the maleic anhydride quaternary ammonium hydrochloride compound is as follows: ； Wherein, R is a C8~C12 alkyl group.

2. The preparation method of the novel high-efficiency bactericide as described in claim 1, characterized in that, The method of the mixed reaction is as follows: the maleic pine carboxylic acid quaternary ammonium hydrochloric anhydride compound and solvent are mixed, (2-hydroxyethyl)triphenylphosphonium chloride is added, and the mixture is stirred at 95~105℃ for 4~5h. Then, silver citrate is added, and the mixture is stirred for another 3~4h.

3. The preparation method of the novel high-efficiency bactericide as described in claim 1, characterized in that, After the mixing reaction is completed, the system is distilled under reduced pressure to remove the solvent, and then dried to obtain a novel high-efficiency bactericide.

4. The preparation method of the novel high-efficiency bactericide as described in claim 1, characterized in that, The preparation method of the maleic pine carboxylic acid quaternary ammonium hydrochloric anhydride compound is as follows: (1) After mixing maleic anhydride glycerol and a monotertiary amine compound in a solvent, hydrochloric acid was added, and the mixture was heated to 80-82°C and stirred under reflux for 48-50 h to obtain maleic anhydride quaternary ammonium salt compound; the molar ratio of nitrogen in the monotertiary amine compound to the molar ratio of epoxy groups in maleic anhydride glycerol was 1.05-1.1:1; the chemical structure of the maleic anhydride glycerol is as follows: ； (2) After reacting trimellitic anhydride acyl chloride and pyridine in a solvent, add maleic anhydride quaternary ammonium salt compound and continue to react to obtain maleic anhydride quaternary ammonium salt compound; the mass ratio of trimellitic anhydride acyl chloride to pyridine is 63.2:28~31, and the molar amount of hydroxyl group in maleic anhydride quaternary ammonium salt compound is equal to the molar amount of trimellitic anhydride acyl chloride.

5. The preparation method of the novel high-efficiency bactericide as described in claim 4, characterized in that, The monomethyl tertiary amine compound is N,N-dimethyln-octylamine, N,N-dimethyln-nonylamine, N,N-dimethyln-decylamine, undecyldimethyl tertiary amine, or dodecyldimethyl tertiary amine.

6. The preparation method of the novel high-efficiency bactericide as described in claim 4, characterized in that, The ratio of the molar amount of HCl in the hydrochloric acid to the molar amount of epoxy groups in the maleic pine carboxylic acid glyceride is 1.2~1.3:

1.

7. The preparation method of the novel high-efficiency bactericide as described in claim 4, characterized in that, After stirring and refluxing for 48-50 h, the solvent was removed by vacuum distillation of the system after stirring and refluxing to obtain crude product. The crude product and methyl isobutyl ketone were mixed at 60 °C in a mass ratio of 1:1.8 and cooled to 15 °C. The mixture was filtered and the filtered solid was dried to obtain the quaternary ammonium salt compound of maleic anhydride carboxylic acid.

8. The preparation method of the novel high-efficiency bactericide as described in claim 4, characterized in that, The reaction of trimellitic anhydride acyl chloride and pyridine in a solvent is carried out at a temperature of 5-8°C for 30-45 minutes.

9. The preparation method of the novel high-efficiency bactericide as described in claim 4, characterized in that, The temperature for the continued mixing reaction is 80~85℃, and the time is 2~3h.

10. A novel high-efficiency bactericide prepared by a method according to any one of claims 1-9.

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