High-stability composite peracetic acid disinfectant and preparation process thereof

Abstract

The invention relates to the technical field of disinfectants, in particular to a high-stability composite peracetic acid disinfectant and a preparation process thereof, and the high-stability composite peracetic acid disinfectant comprises the following components in percentage by mass: 4-6% of peracetic acid, 10-15% of hydrogen peroxide, 15.0-25% of acetic acid, 0.1-0.3% of terpolymer and the balance of water. The stability of PAA and HO is improved, and the decomposition of PAA and HO in the storage process is reduced, so that the durability of the sterilization efficiency of the disinfectant is ensured.

Description

Technical Field

[0001] This invention relates to the field of disinfectant technology, and in particular to a highly stable compound peracetic acid disinfectant and its preparation process. Background Technology

[0002] Peracetic acid disinfectant is a highly effective oxidizing disinfectant, typically produced by the reaction of acetic acid and hydrogen peroxide under catalytic conditions. Chemically, peracetic acid is an acyl-substituted derivative of hydrogen peroxide, exhibiting weak acidity in aqueous solution with a pKa of approximately 8.2, thus existing in both neutral and dissociated states. This disinfectant possesses a high redox potential, giving it broad-spectrum bactericidal capabilities, effectively inactivating various microorganisms such as bacteria, spores, viruses, and molds. Compared to traditional chlorination disinfection, peracetic acid offers significant advantages, including high bactericidal efficiency, low pH dependence, ease of use, and low chemical residue, making it an increasingly important alternative to chlorine disinfectants in water treatment and healthcare applications.

[0003] The invention patent with publication number CN114747575A discloses a peracetic acid disinfectant solution and its preparation method, which includes agent A and agent B. The peracetic acid solution prepared by this invention is stable, convenient to transport, simple to prepare, fast to react, low in foam and corrosiveness, and has good stability. It can be used for high-level disinfection and sterilization.

[0004] In existing technologies, peracetic acid is generated by a dynamic reversible reaction between hydrogen peroxide and acetic acid. This equilibrium is extremely sensitive to temperature, concentration, and pH, and spontaneously shifts towards decomposition during storage, leading to a gradual decrease in the concentration of the active ingredient and affecting disinfection efficacy. Furthermore, high concentrations of peracetic acid and hydrogen peroxide are highly corrosive to most metals and also have an corrosive effect on some plastics, rubbers, and coatings, placing extremely high demands on the materials of storage containers, pipelines, and application equipment. Meanwhile, commonly used inorganic or small-molecule stabilizers such as sodium pyrophosphate, stannates, and organophosphonic acids are often only effective within specific pH or narrow concentration ranges, lacking long-term stability and potentially affecting disinfection efficacy or introducing new toxicity / environmental problems. Summary of the Invention

[0005] To address the problems mentioned in the background section, this invention provides a highly stable composite peracetic acid disinfectant and its preparation process.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A preparation process for a highly stable composite peracetic acid disinfectant includes the following steps:

[0008] S1. Disperse the terpolymer in a solvent to obtain a uniform pre-dispersion;

[0009] S2. Water, glacial acetic acid and hydrogen peroxide solution are mixed for the first time at low temperature to obtain a base solution. Then, the pre-dispersed solution is added to the base solution under stirring. After mixing evenly, the mixture is homogenized to obtain a homogeneous mixture.

[0010] S3. Slowly add peracetic acid solution to the homogeneous mixture obtained in step S2. After the addition is complete, add the remaining water to the total amount of the formula and mix for the second time to obtain the second mixture. Finally, let the second mixture stand for aging under sealed and light-proof conditions to obtain a highly stable composite peracetic acid disinfectant.

[0011] Furthermore, the terpolymer in step S1 is prepared by the following method:

[0012] Hydroxypropyl acrylate, methacryloyloxyethyltrimethylammonium chloride, N-vinylpyrrolidone, and an initiator are dissolved together in a solvent; wherein the mass ratio of hydroxypropyl acrylate, methacryloyloxyethyltrimethylammonium chloride, and N-vinylpyrrolidone is (5.9-8.6):(2-3):1; the initiator is preferably azobisisobutyronitrile, and its amount is 0.3-0.6% of the total mass of the three monomers; the polymerization solvent is selected from water, N,N-dimethylformamide, ethanol, or a mixture of water and ethanol, wherein the volume ratio of water to ethanol in the mixture of water and ethanol is (1:1-4), and the amount of solvent is 5-15 times the total mass of the three monomers.

[0013] Under an inert atmosphere, the reaction system temperature is controlled at 65-75℃, and the reaction is carried out at a stirring speed of 200-400 rpm for 18-30 hours. After the reaction is completed, the resulting reaction solution is transferred to a precipitant to precipitate. The precipitant is selected from acetone, tetrahydrofuran, or diethyl ether, and the volume of the precipitant is 5-10 times the volume of the reaction solution. After precipitation, the precipitate is vacuum filtered, and the filter cake is washed 2-4 times with the precipitant. Then, the filter cake is placed in a vacuum drying oven at 30-50℃ and dried for 12-24 hours to obtain the terpolymer.

[0014] In the dispersion process of step S1, the solvent is selected from glacial acetic acid or a mixture of glacial acetic acid and ethanol. When using a mixture of glacial acetic acid and ethanol, the volume ratio of glacial acetic acid to ethanol is (1:0.5-2), and the mixed solvent is preferably cooled before use at a temperature of 0-10°C. The amount of solvent used is 8-20 times the mass of the terpolymer. The dispersion operation is as follows: at 20-25°C, the terpolymer is gradually added to the solvent, and stirred continuously at a speed of 400-600 rpm for 45-60 minutes to ensure that the copolymer is fully dispersed.

[0015] In step S2, the hydrogen peroxide solution is an aqueous solution of hydrogen peroxide with a mass concentration of 25-35%. The first mixing process is preferably carried out in a reactor with a cooling jacket, with the mixing temperature controlled at 5-15°C, the stirring speed at 100-200 rpm, and the mixing time at 20-60 min. Anchor-type or paddle-type stirring paddles can be selected. After the pre-dispersed liquid is added to the base liquid, the stirring speed during mixing is increased to 300-500 rpm, and the mixing time is 10-30 min to ensure that the initial mixing is uniform.

[0016] The subsequent homogenization process can be achieved in two preferred ways: one is to use a high-pressure homogenizer to circulate the mixture 2-4 times under a pressure of 30-60 MPa; the other is to use a high-shear dispersion emulsifier to process it for 3-10 minutes at a speed of 8000-12000 rpm.

[0017] In step S3, the peracetic acid solution is an aqueous solution of peracetic acid with a mass concentration of 35-45%; when adding the peracetic acid solution dropwise, the dropping rate is controlled at 0.5-2.0 L / min; the second mixing is carried out at a low temperature, with the temperature controlled at 8-12℃, the stirring speed at 300-500 rpm, and the mixing time at 30-90 min.

[0018] The heating and standing maturation process in step S3 includes three stages performed sequentially: the first stage: standing in the dark at a low temperature of 5-10℃ for 20-28 hours; the second stage: heating to 15-20℃ and standing in the dark for 40-56 hours; the third stage: continuing to heat to 20-25℃ and standing in the dark for 96-144 hours; the heating in each stage of the entire maturation process should be carried out slowly, and the heating rate is preferably no more than 5℃ / h.

[0019] According to another aspect of the present invention, a highly stable composite peracetic acid disinfectant prepared by the above-described preparation process is provided. The composition, based on the total mass of the disinfectant, includes: 4-6% peracetic acid, 10-15% hydrogen peroxide, 15.0-25% acetic acid, and 0.1-0.3 wt% of the aforementioned terpolymer, with the balance being water. The pH value of this disinfectant is preferably in the range of 2.0-4.0.

[0020] The beneficial effects of this invention are:

[0021] 1. In the technical solution of this invention, the terpolymer is copolymerized from hydroxypropyl acrylate, methacryloyloxyethyltrimethylammonium chloride, and N-vinylpyrrolidone. In an acidic disinfectant environment, the positively charged quaternary ammonium groups can interact weakly and reversibly with the electronegative oxygen atoms in peracetic acid and hydrogen peroxide molecules through electrostatic interactions. This allows them to interact with active ingredients such as peracetic acid and hydrogen peroxide, as well as solvent molecules, through intermolecular forces such as hydrogen bonds and electrostatic interactions in the disinfectant system. This helps to form a dynamic micro-stabilized environment, which to a certain extent restricts the free movement and harmful collisions of reactive oxygen species. This helps to slow down the spontaneous decomposition rate of peracetic acid and hydrogen peroxide during storage, and has a positive effect on improving the chemical stability of the disinfectant.

[0022] 2. When disinfectants are applied in real-world scenarios, their microstructure may exhibit dynamic response characteristics. The cationic portions of the copolymer segments may undergo interfacial adsorption when near negatively charged microbial surfaces or organic pollutants, which helps promote the local accumulation of active ingredients at the target sites. Therefore, this disinfectant, while possessing potentially improved storage stability, can still exhibit rapid and efficient bactericidal performance, achieving a good balance between storage stability and high efficiency during use.

[0023] 3. In the technical solution of this invention, the presence of terpolymers may have a certain improving effect on the corrosiveness of the disinfectant. Its molecules have the opportunity to form an adsorption layer on the surface of materials such as metal instruments, which to a certain extent blocks the direct contact between highly oxidizing active ingredients and the substrate, and competitively occupies certain active sites on the material surface. This makes the corrosiveness of this disinfectant to common instrument materials expected to be lower than that of traditional peracetic acid solutions, helping to improve the safety of use and compatibility with equipment. Detailed Implementation

[0024] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In the following preparation examples and embodiments, hydroxypropyl acrylate (CAS No.: 25584-83-2) was purchased from Shanghai Amore Biotechnology Co., Ltd., methacryloyloxyethyltrimethylammonium chloride (CAS No.: 5039-78-1) was purchased from Shandong Jiapeng New Materials Co., Ltd., N-vinylpyrrolidone (CAS No.: 88-12-0) and N,N-dimethylformamide (CAS No.: 68-12-2) were purchased from Shanghai Jizhi Biochemical Technology Co., Ltd., and azobisisobutyronitrile (CAS No.: 78-67-1) was purchased from Jinan Century Tongda Chemical Co., Ltd.

[0026] Preparation Example 1

[0027] The terpolymer is prepared by the following steps:

[0028] 24g of hydroxypropyl acrylate, 10g of methacryloyloxyethyltrimethylammonium chloride, 4g of N-vinylpyrrolidone, and 0.114g of initiator azobisisobutyronitrile were dissolved in 152g of ethanol. Under nitrogen protection, the reaction system was heated to 70℃ and stirred at 300rpm for 24h. After the reaction was completed, the resulting viscous reaction solution was slowly poured into 8 times its volume of acetone with stirring. A white flocculent precipitate was formed. The precipitate was vacuum filtered and the filter cake was washed 3 times with a small amount of acetone. The filter cake was then dried in a vacuum drying oven at 40℃ for 18h to obtain a white solid powder, which was then pulverized for later use.

[0029] Preparation Example 2

[0030] The terpolymer is prepared by the following steps:

[0031] 34.4 g of hydroxypropyl acrylate, 12 g of methacryloyloxyethyltrimethylammonium chloride, 4 g of N-vinylpyrrolidone, and 0.252 g of initiator azobisisobutyronitrile were dissolved in a mixed solvent of 302.5 g of water and ethanol (water:ethanol volume ratio = 1:3, total solvent mass = 6 times the total monomer mass). Under nitrogen protection, the mixture was stirred at 68 °C and 250 rpm for 28 h. After the reaction was completed, the reaction solution was slowly poured into 6 times its volume of tetrahydrofuran with stirring to precipitate the solid. The precipitate was then filtered and washed twice with tetrahydrofuran. The precipitate was dried in a vacuum drying oven at 35 °C for 24 h to obtain a white solid powder, which was then pulverized for later use.

[0032] Preparation Example 3

[0033] The terpolymer is prepared by the following steps:

[0034] 20.1 g of hydroxypropyl acrylate, 6.8 g of methacryloyloxyethyltrimethylammonium chloride, 3.4 g of N-vinylpyrrolidone, and 0.092 g of azobisisobutyronitrile (AIB) initiator were dissolved in 151.5 g of N,N-dimethylformamide. The mixture was stirred vigorously at 72 °C and 400 rpm for 20 h under nitrogen protection. After the reaction was completed, the reaction solution was added dropwise to 10 times its volume of tetrahydrofuran to precipitate the product. After filtration, the filter cake was washed four times with tetrahydrofuran. The filter cake was then dried in a vacuum drying oven at 45 °C for 15 h to obtain a white solid powder, which was then pulverized for later use.

[0035] Example 1

[0036] A preparation process for a highly stable composite peracetic acid disinfectant includes the following steps:

[0037] S1. Take 3g of the terpolymer powder obtained in Preparation Example 1 and gradually add it to a mixed solvent of glacial acetic acid and ethanol that has been pre-cooled to 5°C at room temperature (25°C) (glacial acetic acid: ethanol volume ratio = 1:1, total solvent mass 30g). Stir continuously at 500rpm for 50min to obtain a uniform pre-dispersion.

[0038] S2. Add 300g of deionized water and 200g of glacial acetic acid to the reactor, then slowly add 166.7g of a 30% hydrogen peroxide aqueous solution. Control the temperature inside the reactor at 10℃ and mix at a stirring speed of 150rpm for 40min to obtain the base liquid. Under stirring, slowly add the above pre-dispersed liquid to the base liquid. After the addition is complete, increase the stirring speed to 400rpm and continue mixing for 20min. Transfer the initially mixed liquid to a homogenizer and circulate it 3 times under a pressure of 50MPa to obtain a homogenized mixture.

[0039] S3. Transfer the homogenized mixture back to the temperature-controlled reactor and maintain the temperature at 10°C. While stirring (400 rpm), slowly add 75 g of 40% peracetic acid solution at a dropping rate of 1.0 L / min. After the addition is complete, add deionized water to bring the total mass to 1000 g. Continue mixing at 10°C and 400 rpm for 60 min to obtain the second mixture. Transfer the second mixture to a brown glass container and seal it. Perform programmed temperature rise and stand-up maturation: first, stand at 8°C in the dark for 24 h, then raise the temperature to 18°C ​​and stand in the dark for 48 h, and finally stand at 23°C in the dark for 120 h to obtain the composite peracetic acid disinfectant solution.

[0040] Example 2

[0041] A preparation process for a highly stable composite peracetic acid disinfectant includes the following steps:

[0042] S1. Take 2g of the terpolymer obtained in Preparation Example 2, add it to 20g of glacial acetic acid at room temperature (25℃), and stir at 22℃ and 550rpm for 60min to completely disperse it and obtain a uniform pre-dispersion.

[0043] S2. Add 400g of deionized water and 150g of glacial acetic acid to the reactor, then slowly add 142.9g of 35% hydrogen peroxide solution. Control the temperature at 5℃ and stir at 120rpm for 60min. Add the pre-dispersed liquid while stirring. After the addition is complete, increase the speed to 350rpm and mix for 15min. Use a high-shear dispersing emulsifier to treat the mixture at 10000rpm for 8min to obtain a homogeneous mixture.

[0044] S3. Transfer the homogenized mixture back to the temperature-controlled reactor and maintain the temperature at 8°C. While stirring (350 rpm), add 52.6 g of 38% peracetic acid solution at a rate of 0.8 L / min. Add water to bring the total mass to 1000.0 g. Mix at 8°C and 350 rpm for 90 min to obtain a second mixture. Transfer the second mixture to a brown glass container and seal it. Perform programmed temperature rise and stand-up curing: first, stand at 5°C in the dark for 28 h, then raise the temperature to 16°C and stand in the dark for 52 h, and finally stand at 20°C in the dark for 144 h to obtain a compound peracetic acid disinfectant solution.

[0045] Example 3

[0046] A preparation process for a highly stable composite peracetic acid disinfectant includes the following steps:

[0047] S1. Take 1g of the terpolymer obtained in Preparation Example 3 and add it to a mixed solvent of glacial acetic acid and ethanol that has been pre-cooled to 0°C at room temperature (25°C) (glacial acetic acid: ethanol volume ratio = 1:0.5, total solvent mass 10g). Stir continuously at 400rpm for 50min to obtain a uniform pre-dispersion.

[0048] S2. Add 350g of deionized water and 250g of glacial acetic acid to the reactor, then slowly add 200g of 25% hydrogen peroxide solution. Control the temperature inside the reactor at 15℃ and stir at 200rpm for 20min to obtain the base liquid. While stirring, slowly add the above pre-dispersed liquid to the base liquid. After the addition is complete, increase the stirring speed to 500rpm and continue mixing for 10min. Transfer the initially mixed liquid to a homogenizer and circulate it twice under a pressure of 60MPa to obtain a homogenized mixture.

[0049] S3. Transfer the homogenized mixture back to the temperature-controlled reactor and control the temperature at 12℃. While stirring (500 rpm), slowly add 66.7 g of 45% peracetic acid solution at a dropping rate of 2.0 L / min. Add water to bring the total mass to 1000 g. Mix at 12℃ and 500 rpm for 30 min to obtain a second mixture. Transfer the second mixture to a brown glass container and seal it. Perform programmed temperature rise and stand for maturation: first, stand at 10℃ in the dark for 20 h, then raise the temperature to 20℃ and stand in the dark for 40 h, and finally stand at 25℃ in the dark for 96 h to obtain a compound peracetic acid disinfectant solution.

[0050] Example 4

[0051] This embodiment is basically the same as Embodiment 1, with the main difference being:

[0052] In S1, 2.5g of the terpolymer obtained in Preparation Example 1 was taken and dispersed in a mixed solvent of glacial acetic acid and ethanol (glacial acetic acid: ethanol volume ratio = 1:1.5, total solvent mass 30g), and stirred at 23℃ and 450rpm for 55min.

[0053] In S2, the first mixing temperature was 8℃, the stirring speed was 180rpm, and the mixing time was 50min; after adding the pre-dispersed liquid, the mixture was mixed at 380rpm for 25min; the homogenization treatment pressure was 40MPa, and the cycle was repeated 4 times.

[0054] In S3, a 42% peracetic acid solution was added dropwise at a rate of 1.5 L / min; the second mixing temperature was 9℃, the stirring speed was 450 rpm, and the mixing time was 75 min; the maturation program was: 7℃ for 26 h, 17℃ for 50 h, and 22℃ for 132 h.

[0055] Example 5

[0056] The difference between this embodiment and Embodiment 2 is as follows:

[0057] In S1, 2.2g of the terpolymer obtained in Preparation Example 3 was taken, and 25g of glacial acetic acid was used as the solvent. The dispersion conditions were stirring at 25°C and 500rpm for 50min.

[0058] In S2, the hydrogen peroxide solution has a mass concentration of 32%; the first mixing temperature is 12℃, the stirring speed is 180rpm, and the mixing time is 30min; the high shear dispersion emulsifier speed is 9000rpm, and the processing time is 10min.

[0059] In S3, a 36% peracetic acid solution was added dropwise at a rate of 0.6 L / min; the second mixing temperature was 11℃, the stirring speed was 380 rpm, and the mixing time was 100 min; the maturation program was: standing at 6℃ for 26 h, standing at 19℃ for 44 h, and standing at 24℃ for 100 h.

[0060] Example 6

[0061] The difference between this embodiment and embodiment 3 is as follows:

[0062] In S1, 1.5g of the terpolymer obtained in Preparation Example 2 was taken and dispersed in 12g of a mixed solvent of glacial acetic acid and ethanol (volume ratio 1:1.8) pre-cooled to 8°C, and stirred at 21°C and 480rpm for 60min.

[0063] In S2, the amount of glacial acetic acid used is 220g, and the mass concentration of hydrogen peroxide solution is 28%; the first mixing temperature is 7℃, the stirring speed is 180rpm, and the mixing time is 45min; the homogenization treatment pressure is 35MPa, and the cycle is repeated 3 times.

[0064] In S3, a 40% peracetic acid solution was added dropwise at a rate of 1.2 L / min; the second mixing temperature was 10℃, the stirring speed was 420 rpm, and the mixing time was 45 min; the maturation program was: 9℃ for 22 h, 18℃ for 52 h, and 21℃ for 140 h.

[0065] Example 7

[0066] The difference between this embodiment and Embodiment 1 is that:

[0067] In S1, the amount of terpolymer used was 2.8g, the solvent was glacial acetic acid: ethanol (volume ratio 1:0.8), the total mass was 35g, the dispersion speed was 550rpm, and the time was 45min.

[0068] In S2, the amount of water used is 280g, the amount of glacial acetic acid used is 230g, and the amount of hydrogen peroxide solution (concentration 33%) used is 151.5g; the first mixing temperature is 13℃, the stirring speed is 160rpm; the homogenization pressure is 45MPa, and the cycle is repeated twice.

[0069] In S3, the concentration of peracetic acid solution was 41%, and the amount used was 71.4g; the second mixing temperature was 11℃, and the stirring speed was 480rpm; the maturation conditions were: standing at 6℃ for 26h, standing at 16℃ for 54h, and standing at 25℃ for 110h.

[0070] Comparative Example 1

[0071] The difference between this comparative example and Example 1 is that no terpolymer is added in step S1, while the remaining steps are the same as in Example 1.

[0072] Comparative Example 2

[0073] The difference between this comparative example and Example 2 is that in step S1, an equal mass of hydroxypropyl acrylate is used to replace the terpolymer, while the remaining steps are the same as in Example 2.

[0074] Comparative Example 3

[0075] The difference between this comparative example and Example 3 is that in step S1, an equal mass of methacryloyloxyethyltrimethylammonium chloride is used to replace the terpolymer, while the remaining steps are the same as in Example 3.

[0076] Comparative Example 4

[0077] The difference between this comparative example and Example 4 is that in step S1, an equal mass of N-vinylpyrrolidone is used to replace the terpolymer, while the remaining steps are the same as in Example 4.

[0078] Comparative Example 5

[0079] The difference between this comparative example and Example 5 is that in step S1, sodium pyrophosphate of equal mass is used instead of the terpolymer, while the remaining steps are the same as in Example 5.

[0080] Take 80 mL samples of disinfectant solutions prepared in Examples 1-7 and Comparative Examples 1-5 and store them in brown glass bottles. Samples are taken at the start of storage (day 0) and on days 7, 14, 30, 60, and 90 after storage. Before each sampling, gently shake the sample bottle several times to ensure thorough mixing.

[0081] (I) Determination of peracetic acid (PAA) content: Refer to GB / T 19104-2021 "Peracetic acid solution", measure V1 mL of each sample (PAA content is 0.1g) and place it in a 250mL iodine flask, add 10mL of sulfuric acid solution (volume fraction 20%), shake well, add 10mL of potassium iodide solution (100g / L), tighten the stopper, shake well, place in the dark for 10min, titrate with sodium thiosulfate standard solution (0.1mol / L) until the solution turns pale yellow, add 1mL of starch indicator solution (5g / L), the solution turns blue, continue titrating until the blue color disappears, and record the volume of sodium thiosulfate consumed, V2 (mL). Simultaneously, a blank test was performed (using an equal volume of water instead of the sample), and the volume of sodium thiosulfate consumed, V0 (mL), was recorded. The PAA content (g / L) was calculated as [c×(V2-V0)×38.03] / (2×V1)×1000, and the PAA residue rate (%) at each time point was calculated as (PAA content at that time point / PAA content on day 0)×100%. The results are shown in Table 1.

[0082] Table 1. Peracetic acid residue rate (%) of various disinfectant samples at different storage time points

[0083]

[0084] (II) Determination of hydrogen peroxide (H2O2) content: Measure V3 mL of each sample (H2O2 content is 1 g) and place it in a 250 mL Erlenmeyer flask. Add 10 mL of sulfuric acid solution (volume fraction 20%), and titrate with potassium permanganate standard solution c (0.02 mol / L) until the solution turns slightly red and does not fade within 30 seconds. Record the volume of potassium permanganate consumed, V4 (mL). Calculate the H2O2 content (g / L) = [c × V4 × 17.01] / (2 × V3) × 1000. Calculate the H2O2 residual rate (%) at each time point = (H2O2 content at that time point / H2O2 content on day 0) × 100%. The results are shown in Table 2:

[0085] Table 2. Hydrogen peroxide residue rate (%) of various disinfectant samples at different storage time points

[0086]

[0087] (III) Bactericidal efficacy test: Samples stored for 0 days and 90 days were tested. Freeze-dried Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 25922) strains were revived, subcultured, and typical colonies were inoculated into nutrient broth and incubated at 37°C for 24 hours. The broth was then diluted with phosphate-buffered saline (PBS, pH=7.2) to a concentration of 1×10⁻⁶. 8 CFU / mL bacterial suspension.

[0088] The disinfectant samples from Examples 1-3 and Comparative Example 1 were diluted with sterile water to a series of concentrations (final PAA concentrations of 50 mg / L and 100 mg / L). 2.0 mL of each diluted disinfectant was placed in a sterile test tube and incubated in a water bath at 20 ± 1 °C for 5 min. 0.1 mL of bacterial suspension was added, and the mixture was immediately mixed and timed. After predetermined times (1 min, 5 min, 10 min), 0.5 mL of the bacterial-drug mixture was immediately removed and added to 4.5 mL of a neutralizing agent (PBS solution containing 0.5% sodium thiosulfate, 0.5% lecithin, and 3% Tween 80) pre-warmed to 20 °C. The mixture was mixed and allowed to stand for 10 min to terminate the reaction. A 10-fold serial dilution was performed using the neutralizing agent. 1.0 mL of the diluted solution was inoculated into a sterile Petri dish, poured into nutrient agar medium cooled to 45 °C, shaken well, and allowed to solidify.

[0089] Incubate the petri dishes at 37°C for 48 hours, then count the colonies (spores require 72 hours of incubation). Calculate the logarithmic kill value (KL) = lgN0 - lgN x Where N0 is the average viable bacterial concentration (CFU / mL) of the positive control group, N xIt is the average viable bacteria concentration (CFU / mL) after the test group acts for t time. When KL≥3.00 (that is, the killing rate ≥99.9%), it is judged as qualified disinfection. The results are shown in Table 3-4:

[0090] Table 3. Disinfection effects of disinfectants with different concentrations on Escherichia coli (E.coli)

[0091]

[0092] Table 4. Disinfection effects of disinfectants with different concentrations on Staphylococcus aureus (S.aureus)

[0093]

[0094] As can be seen from Table 1, the residual rates of peracetic acid (PAA) in Examples 1-7 remained at 95.0-96.2% after 90 days of storage, indicating that the disinfectant added with terpolymer decomposed less PAA during storage and had good stability. In Comparative Example 1, no terpolymer was added, and the PAA residual rate at 90 days was only 63.5%; in Comparative Examples 2-4, the monomer components of the terpolymer were used to replace the terpolymer respectively, and the PAA residual rate at 90 days was between 72.0-83.5%; in Comparative Example 5, sodium pyrophosphate was used to replace the terpolymer, and the PAA residual rate at 90 days was 82.0%. The PAA residual rates of the comparative examples were significantly lower than those of the examples, indicating that the terpolymer plays an important role in improving the stability of PAA. Some groups in the terpolymer may form complexes with PAA molecules, reducing the contact between PAA and other substances (such as water, oxygen, etc.) in the environment, thereby reducing the decomposition rate of PAA. The macromolecular structure of the terpolymer can form steric hindrance around PAA, hindering the approach of PAA molecules to other reactants and slowing down the decomposition reaction of PAA.

[0095] As can be seen from Table 2, the residual rates of hydrogen peroxide (H2O2) in Examples 1-7 remained at 96.2-97.5% after 90 days of storage, indicating that the terpolymer also has a certain stabilizing effect on H2O2. In Comparative Example 1, no terpolymer was added, and the H2O2 residual rate at 90 days was 74.5%; in Comparative Examples 2-4, the monomer components were used to replace the terpolymer respectively, and the H2O2 residual rate at 90 days was between 81.3-89.4%; in Comparative Example 5, sodium pyrophosphate was used to replace the terpolymer, and the H2O2 residual rate at 90 days was 87.8%, further proving the effectiveness of the terpolymer in improving the stability of H2O2. The terpolymer may have antioxidant properties, be able to scavenge free radicals generated in the system, reduce the attack of free radicals on H2O2, and thus reduce the decomposition rate of H2O2. Similar to PAA, the terpolymer may also form a stable complex with H2O2 to protect H2O2 from decomposition.

[0096] As shown in Tables 3-4, Examples 1-3 exhibited good bactericidal effects against Escherichia coli and Staphylococcus aureus at different concentrations on day 0. Most bacteria achieved a kill log (KL) of 5.00 or higher within 5 minutes, indicating that the disinfectant possessed strong bactericidal capabilities in its initial state. Although the bactericidal effect slightly decreased after 90 days, at a PAA concentration of 100 mg / L, the KL for both bacteria still reached or exceeded 5.00 within 10 minutes, demonstrating that the disinfectant retained good bactericidal efficacy even after 90 days of storage.

[0097] Comparative Example 1 also showed some bactericidal effect at day 0, but the bactericidal effect decreased significantly at day 90. At a PAA concentration of 50 mg / L, the KL values ​​at 1 min and 5 min were extremely low, even failing to meet the disinfection qualification standard, indicating that the bactericidal efficacy of the disinfectant without the added terpolymer was significantly reduced during storage. The added terpolymer in the examples improved the stability of PAA and H2O2, resulting in less decomposition of the active ingredients during storage, thus ensuring the durability of the bactericidal efficacy. The terpolymer may have a synergistic effect with PAA and H2O2, enhancing the bactericidal effect of the disinfectant. For example, the terpolymer may alter the permeability of bacterial cell membranes, making it easier for PAA and H2O2 to enter bacterial cells and exert their effects.

[0098] In summary, the embodiments improved the stability of PAA and H2O2, reducing their decomposition during storage, thereby ensuring the long-lasting bactericidal efficacy of the disinfectant.

[0099] In the description of this specification, the reference to terms such as "embodiment," "various embodiments," etc., indicates that a specific feature, structure, material, or characteristic described in connection with that embodiment or preparation example is included in at least one embodiment of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments.

[0100] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A preparation process for a highly stable composite peracetic acid disinfectant, characterized in that, Includes the following steps: S1. Disperse the terpolymer in a solvent to obtain a pre-dispersion; S2. Water, glacial acetic acid and hydrogen peroxide solution are mixed for the first time to obtain a base solution. The pre-dispersed solution is added under stirring, and after mixing, the mixture is homogenized to obtain a homogeneous mixture. S3. Add peracetic acid solution dropwise to the homogeneous mixture. After the addition is complete, add water to the total volume and mix for the second time to obtain a second mixture. Place the second mixture under sealed and light-proof conditions and allow it to stand and mature at a high temperature to obtain a highly stable composite peracetic acid disinfectant solution.

2. The preparation process according to claim 1, characterized in that, The terpolymer in step S1 is obtained by the following steps: Hydroxypropyl acrylate, methacryloyloxyethyltrimethylammonium chloride, N-vinylpyrrolidone and an initiator were dissolved in a solvent and reacted under an inert atmosphere with controlled temperature and stirring. After the reaction was completed, the reaction solution was transferred to a precipitant for precipitation. After filtration, washing and drying, a terpolymer was obtained.

3. The preparation process according to claim 1, characterized in that, In step S1, the solvent is selected from glacial acetic acid or a mixture of glacial acetic acid and ethanol, and the amount of solvent used is 8-20 times the mass of the terpolymer. The dispersion process includes: adding the terpolymer to the solvent at 20-25°C and stirring at 400-600 rpm for 45-60 min.

4. The preparation process according to claim 1, characterized in that, In step S2, the hydrogen peroxide solution is an aqueous solution with a mass concentration of 25-35%; the homogenization treatment is carried out by a homogenizer at a pressure of 30-60 MPa, and the process is repeated 2-4 times; or by a shearing machine at a speed of 8000-12000 rpm for 3-10 minutes.

5. The preparation process according to claim 1, characterized in that, In step S2, the temperature for the first mixing is 5-15℃, the stirring speed is 100-200rpm, and the mixing time is 20-60min.

6. The preparation process according to claim 1, characterized in that, In step S3, the peracetic acid solution is an aqueous solution of peracetic acid with a mass concentration of 35-45%; the temperature during the second mixing is 8-12℃, the stirring speed is 300-500rpm, and the mixing time is 30-90min.

7. The preparation process according to claim 1, characterized in that, Step S3, which involves heating and resting for maturation, includes three stages: first, resting at 5-10℃ in the dark for 20-28 hours; then, resting at 15-20℃ in the dark for 40-56 hours; and finally, resting at 20-25℃ in the dark for 96-144 hours.

8. The preparation process according to claim 2, characterized in that, The mass ratio of hydroxypropyl acrylate, methacryloyloxyethyltrimethylammonium chloride and N-vinylpyrrolidone is (5.9-8.6):(2-3):1; the initiator is selected from azobisisobutyronitrile, and its amount is 0.3-0.6% of the total mass of hydroxypropyl acrylate, methacryloyloxyethyltrimethylammonium chloride and N-vinylpyrrolidone.

9. The preparation process according to claim 2, characterized in that, The reaction temperature during stirring is controlled at 65-75℃, the stirring speed is 200-400rpm, and the reaction time is 18-30h.

10. A highly stable composite peracetic acid disinfectant prepared by the process described in claims 1-9, characterized in that, The total mass of the disinfectant solution includes: 4-6% peracetic acid, 10-15% hydrogen peroxide, 15.0-25% acetic acid, and 0.1-0.3 wt% terpolymer, with the balance being water.

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