A stable antibacterial ink and a method for preparing the same

Abstract

This invention relates to the field of water-based ink technology, and discloses a stable antibacterial ink and its preparation method. The stable antibacterial ink of this invention comprises the following raw materials in parts by weight: 25-40 parts acrylic acid, 15-25 parts isooctyl acrylate, 10-15 parts butyl methacrylate, 5-8 parts composite antibacterial agent, 1-5 parts modified graphene oxide, 5-8 parts emulsifier, 200-250 parts deionized water, 0.1-0.3 parts initiator, 5-10 parts pigment, and 7-10 parts anhydrous ethanol. The composite antibacterial agent of this invention can effectively inhibit the growth and reproduction of various common pathogenic bacteria, preventing the ink surface from developing odors, mold, or cross-contamination due to microbial contamination. The modified antistatic agent can significantly reduce the surface resistance of the ink coating and dissipate accumulated static charge in a timely manner, thereby further improving the antibacterial and cleaning effect and printing accuracy of the ink.

Description

Technical Field

[0001] This invention relates to the field of water-based ink technology, specifically to a stable antibacterial ink and its preparation method. Background Technology

[0002] With increasingly stringent global environmental regulations, low-VOC, solvent-free water-based inks have gradually replaced traditional solvent-based inks, becoming the mainstream printing material in fields such as food and pharmaceutical packaging, baby product printing, electronic component labeling, and public signage. However, current mainstream water-based ink systems still have significant functional shortcomings, making it difficult to meet the high-performance requirements of various scenarios. Water-based inks use water as a dispersion medium, making the system itself prone to the growth of bacteria, mold, and other microorganisms. Furthermore, after ink printing and film formation, the microporous structure of the film surface provides a breeding ground for bacteria. Existing conventional antibacterial additives are mostly inorganic silver-based or organic quaternary ammonium salts, which generally suffer from poor compatibility with water-based resins, easy migration and precipitation, short antibacterial duration, and the potential to induce drug resistance in bacteria with long-term use, failing to achieve long-term stable antibacterial effects in the ink system. In addition, after water-based ink film formation, the resin matrix itself has strong insulation and high surface resistivity, making it highly susceptible to static electricity accumulation due to friction during printing, leading to problems such as plate clogging, ink splatter, and pattern distortion, severely affecting printing accuracy and production efficiency.

[0003] Patent application number 201610115236.9 discloses an antibacterial water-based ink and its preparation method. The antibacterial agent used is nano-silver containing functionalized surface groups. However, nano-silver may cause allergic reactions in some people upon skin contact, and long-term use may lead to pathogen adaptability, reducing the antibacterial effect. Patent application number 201810885707.3 discloses a novel environmentally friendly antistatic water-based plastic gravure printing ink. It uses a quaternary ammonium salt cationic antistatic agent to improve the antistatic properties of the ink, but its compatibility with the substrate is poor when used alone, and the antistatic effect cannot be maintained for a long time. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a stable antibacterial ink and its preparation method.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A stable antibacterial ink comprises the following raw materials in parts by weight: 25-40 parts acrylic acid, 15-25 parts isooctyl acrylate, 10-15 parts butyl methacrylate, 5-8 parts composite antibacterial agent, 1-5 parts modified graphene oxide, 5-8 parts emulsifier, 200-250 parts deionized water, 0.1-0.3 parts initiator, 5-10 parts pigment, and 7-10 parts anhydrous ethanol;

[0007] The emulsifier is prepared by compounding fatty alcohol polyoxyethylene ether and sodium dodecylbenzene sulfonate in a mass ratio of 2:1.

[0008] The initiator is azobisisopropylimidazoline;

[0009] The pigment is one of phthalocyanine blue, permanent yellow, phthalocyanine green, permanent red, and carbon black;

[0010] The composite antibacterial agent is prepared by the following steps:

[0011] Step A1: Mix 2-mercaptothiazole, 2,3-epoxypropyltrimethylammonium chloride, triethylamine and methanol, react at 45°C for 3.5 h, then rotary evaporate and vacuum dry to obtain intermediate product 1;

[0012] Furthermore, the ratio of 2-mercaptothiazole, 2,3-epoxypropyltrimethylammonium chloride, triethylamine, and methanol is 0.2-0.4 mol: 0.24-0.48 mol: 0.78-1.56 g: 300-600 mL;

[0013] In step A1, 2-mercaptothiazole and 2,3-epoxypropyltrimethylammonium chloride undergo a ring-opening reaction, introducing a hydroxyl group into the system and providing reaction conditions for the subsequent esterification reaction. The nitrogen and sulfur atoms in the thiazole structure have electron-rich properties, which are conducive to binding with biomolecules in vivo through non-covalent interactions, destroying the cell wall structure and causing bacterial death. The quaternary ammonium salt carries a positive charge, which is conducive to its adsorption on the bacterial surface, further improving the antibacterial properties of the system.

[0014] Step A2: Mix p-aldehyde benzoic acid, intermediate product 1, p-toluenesulfonic acid and toluene, stir and heat to 140°C, reflux until no obvious water droplets are formed, after the reaction is complete, add ethyl acetate, wash with 10wt% sodium bicarbonate solution until pH is 8, then wash with deionized water and saturated sodium chloride solution in sequence, separate, dry, filter, distill under reduced pressure and dry to obtain intermediate product 2.

[0015] Furthermore, the ratio of the amounts of p-aldehyde benzoic acid, intermediate 1, p-toluenesulfonic acid, toluene, ethyl acetate, deionized water, and saturated sodium chloride solution is 0.1-0.3 mol : 0.095-0.285 mol : 0.01-0.03 mol : 150-350 mL : 200-300 mL : 300 mL : 300 mL;

[0016] In step A2, esterification of aldehyde benzoic acid and intermediate 1 occurs, introducing the aldehyde group into the system and providing reaction conditions for the subsequent reductive amination reaction.

[0017] Step A3: Mix 2,2-dipyridinemethylamine, intermediate 2 and dichloromethane, and react at room temperature for 1 hour under argon protection. Add sodium triacetoxyborohydride and continue the reaction at room temperature for 11 hours. After the reaction is completed, add deionized water, and then extract and purify to obtain intermediate 3.

[0018] Furthermore, the ratio of 2,2-dipyridinemethylamine, intermediate 2, dichloromethane, sodium triacetoxyborohydride, and deionized water is 0.02-0.04 mol: 0.02-0.04 mol: 100-200 mL: 0.06-0.12 mol: 150-300 mL;

[0019] In step A3, 2,2-dipyridinemethylamine and intermediate 2 undergo a reductive amination reaction, introducing the dipyridine structure into the system and providing reaction conditions for the subsequent chelation coordination reaction.

[0020] Step A4: Mix anhydrous zinc chloride and methanol, then add intermediate product 3 solution dropwise, react at room temperature under argon for 6 hours, evaporate to dryness under vacuum, extract with dichloromethane and saturated sodium chloride aqueous solution, and evaporate to dryness to obtain composite antibacterial agent;

[0021] Furthermore, the ratio of anhydrous zinc chloride, methanol, intermediate product 3 solution, dichloromethane, and saturated sodium chloride aqueous solution is 0.012-0.024 mol: 50-100 mL: 30-60 mL: 200-300 mL: 150-250 mL;

[0022] Furthermore, the intermediate product 3 solution is prepared by mixing intermediate product 3 and methanol in a volume ratio of 0.01-0.02 mol: 30-60 mL;

[0023] In step A4, anhydrous zinc chloride and intermediate product 3 undergo a chelation coordination reaction. Zinc ions can disrupt the integrity of the cell membrane, thereby affecting the physiological metabolic processes of bacteria. They can also interfere with the enzyme activity inside bacteria, inhibiting their growth and reproduction. After complexation, the bactericidal ability of zinc ions is further enhanced. It works synergistically with thiazole and quaternary ammonium salt structures, exhibiting good biosafety and being less likely to induce drug resistance in bacteria.

[0024] The modified graphene oxide is prepared by the following steps:

[0025] Step B1: Mix isopropanol and bromopropane, add pyridine-2,6-dicarboxaldehyde solution dropwise while stirring, reflux at 90°C for 48 h, after the reaction is complete, rotary evaporate, add the obtained product dropwise to ethyl acetate, precipitate, wash, filter, and vacuum dry to obtain dicarboxaldehyde pyridine bromide.

[0026] Furthermore, the ratio of isopropanol, bromopropane, pyridine-2,6-dicarboxaldehyde solution and ethyl acetate is 120-240 mL : 0.12-0.24 mol : 80-160 mL : 350-600 mL;

[0027] Furthermore, the pyridine-2,6-dicarboxaldehyde solution is prepared by mixing pyridine-2,6-dicarboxaldehyde and isopropanol in a volume ratio of 0.1-0.2 mol: 80-160 mL;

[0028] In step B1, pyridine-2,6-dicarboxaldehyde and bromopropane undergo a quaternization reaction, introducing bromide ions into the system to provide reaction conditions for subsequent ion exchange reactions. Dicarboxaldehyde provides reaction conditions for subsequent polycondensation reactions. The generated pyridine salt carries a positive charge and can neutralize the negative charge generated on the material surface due to friction through electrostatic attraction, thereby reducing static electricity accumulation. It also has a certain antibacterial effect.

[0029] Step B2: Mix diformaldehyde pyridine bromide and potassium hexafluorophosphate, add acetonitrile, and reflux at 70°C for 48 hours under an argon atmosphere. Filter, rotary evaporate, wash, and vacuum dry the product to obtain diformaldehyde pyridine hexafluorophosphate.

[0030] Furthermore, the ratio of dimethylformaldehyde pyridine bromide, potassium hexafluorophosphate, and acetonitrile is 0.03-0.06 mol: 0.00375-0.075 mol: 50-100 mL;

[0031] In step B2, diformaldehyde pyridine bromide and potassium hexafluorophosphate undergo an ion exchange reaction. The introduced hexafluorophosphate is an anion. The simultaneous introduction of cations and anions into the system increases the conductivity of the system, allows for the rapid migration of accumulated static charge, and enhances the antistatic ability.

[0032] Step B3: Mix graphene oxide and anhydrous ethanol, sonicate for 30 min, add 1,3,5-triaminobenzene, stir, then add diformaldehyde pyridine hexafluorophosphate solution dropwise, reflux at 80℃ for 6 h, cool to room temperature, filter, wash three times with 60℃ ethanol solution, and dry to obtain modified graphene oxide.

[0033] Furthermore, the ratio of graphene oxide, anhydrous ethanol, 1,3,5-triaminobenzene, diformaldehyde pyridine hexafluorophosphate solution and 60℃ ethanol solution is 0.4g: 40-80mL: 0.005-0.01mol: 30-60mL: 90-180mL;

[0034] Furthermore, the diformaldehyde pyridine hexafluorophosphate solution is prepared by mixing diformaldehyde pyridine hexafluorophosphate and anhydrous ethanol at a volume ratio of 0.01-0.02 mol: 30-60 mL;

[0035] In step B3, 1,3,5-triaminobenzene and diformaldehyde pyridine hexafluorophosphate are in situ composited between graphene oxide sheets. Graphene oxide has excellent conductivity and mechanical properties. The sheet structure broadens the charge dissipation path, avoids the continuous accumulation of static charge, and forms a dual conductive network in synergy with cations and anions, which can significantly reduce the surface resistivity of the material and achieve a long-term and stable antistatic effect.

[0036] A method for preparing a stable antibacterial ink includes the following steps:

[0037] Step S1: Mix acrylic acid, isooctyl acrylate, butyl methacrylate, composite antibacterial agent, modified graphene oxide and emulsifier evenly and add to deionized water. Disperse at high speed to obtain an emulsion. Then add an initiator to initiate the polymerization reaction. After the reaction is completed, the binder is obtained.

[0038] Step S2: After preliminary mixing of the binder, pigment, anhydrous ethanol and deionized water obtained in step S1, add them to a single-tank planetary high-energy ball mill and grind for 2-5 hours with high-speed stirring to obtain water-based acrylic resin ink.

[0039] The beneficial effects of this invention are:

[0040] The stable antibacterial ink of this invention can be widely used in the production of food packaging, medical devices, electronic products, and public facilities. The antibacterial ink of this invention achieves a broad-spectrum, highly efficient, and long-lasting antibacterial effect through the synergistic effect of composite antibacterial agents, effectively inhibiting the growth and reproduction of various common pathogenic bacteria and preventing odors, mold, or cross-contamination on printed surfaces due to microbial contamination. Simultaneously, the introduction of modified antistatic agents significantly reduces the surface resistance of the ink coating, promptly dissipating accumulated static charge and effectively avoiding problems such as plate clogging, ink splatter, and pattern distortion, thereby further improving the antibacterial and cleaning effect of the ink and printing accuracy.

[0041] The composite antibacterial agent of this invention first undergoes a ring-opening reaction with 2-mercaptothiazole and 2,3-epoxypropyltrimethylammonium chloride. The nitrogen and sulfur atoms in the thiazole structure are electron-rich, which facilitates binding with biomolecules in vivo through non-covalent interactions, disrupting cell wall structure and leading to bacterial death. The quaternary ammonium salt carries a positive charge, which is conducive to its adsorption on the bacterial surface, further enhancing the antibacterial activity of the system. Subsequently, it undergoes an esterification reaction with p-aldehyde benzoic acid to introduce an aldehyde group into the system, followed by a reductive amination reaction to introduce a dipyridine structure into the system. Finally, it undergoes a chelation coordination reaction with anhydrous zinc chloride. Zinc ions can disrupt the integrity of the cell membrane, thereby affecting the physiological metabolic processes of bacteria, and can also interfere with the enzyme activity inside bacteria, inhibiting their growth and reproduction. After complexation, the bactericidal ability is further enhanced. Synergistically acting with the thiazole and quaternary ammonium salt structures, it has good biocompatibility and is unlikely to induce bacterial resistance.

[0042] The modified graphene oxide of this invention first undergoes a quaternization reaction with pyridine-2,6-dicarboxaldehyde and bromopropane. The resulting pyridine salt carries a positive charge and can neutralize the negative charge generated on the material surface due to friction through electrostatic attraction, thereby reducing static charge accumulation and also exhibiting a certain antibacterial effect. Subsequently, it undergoes an ion exchange reaction with potassium hexafluorophosphate. The introduced hexafluorophosphate is an anion, simultaneously introducing cations and anions into the system, improving the conductivity and enabling rapid migration of accumulated static charge, thus enhancing antistatic capabilities. Finally, 1,3,5-triaminobenzene and dicarboxaldehyde pyridine hexafluorophosphate are in situ composited between the graphene oxide sheets. The graphene oxide possesses excellent conductivity and mechanical properties; the sheet structure broadens the charge dissipation path, preventing continuous accumulation of static charge. It synergistically forms a dual-conductive network with cations and anions, significantly reducing the surface resistivity of the material and achieving a long-lasting and stable antistatic effect. Detailed Implementation

[0043] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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.

[0044] Example 1: The compound antibacterial agent was prepared by the following steps:

[0045] Step A1: Mix 2-mercaptothiazole, 2,3-epoxypropyltrimethylammonium chloride, triethylamine and methanol, react at 45°C for 3.5 h, then rotary evaporate and vacuum dry to obtain the intermediate product. The molar ratio of 1,2-mercaptothiazole, 2,3-epoxypropyltrimethylammonium chloride, triethylamine and methanol is 0.2 mol: 0.24 mol: 0.78 g: 300 mL.

[0046] Step A2: Mix p-aldehyde benzoic acid, intermediate product 1, p-toluenesulfonic acid, and toluene, stir and heat to 140°C, reflux until no obvious water droplets are formed. After the reaction is complete, add ethyl acetate, wash with 10wt% sodium bicarbonate solution until pH is 8, then wash with deionized water and saturated sodium chloride solution in sequence, separate, dry, filter, distill under reduced pressure, and dry to obtain intermediate product 2. The ratio of p-aldehyde benzoic acid, intermediate product 1, p-toluenesulfonic acid, toluene, ethyl acetate, deionized water, and saturated sodium chloride solution is 0.1mol:0.095mol:0.01mol:150mL:200mL:300mL:300mL.

[0047] Step A3: Mix 2,2-dipyridinemethylamine, intermediate 2, and dichloromethane, and react at room temperature for 1 hour under argon protection. Add sodium triacetoxyborohydride and continue reacting at room temperature for 11 hours. After the reaction is complete, add deionized water, and then extract and purify to obtain intermediate 3. The ratio of intermediate 3,2,2-dipyridinemethylamine, intermediate 2, dichloromethane, sodium triacetoxyborohydride, and deionized water is 0.02 mol: 0.02 mol: 100 mL: 0.06 mol: 150 mL.

[0048] Step A4: Mix anhydrous zinc chloride and methanol, then add intermediate product 3 solution dropwise, react at room temperature under argon for 6 hours, evaporate to dryness under vacuum, extract with dichloromethane and saturated sodium chloride aqueous solution, and evaporate to dryness to obtain composite antibacterial agent. The volume ratio of anhydrous zinc chloride, methanol, intermediate product 3 solution, dichloromethane and saturated sodium chloride aqueous solution is 0.012 mol: 50 mL: 30 mL: 200 mL: 150 mL. Intermediate product 3 solution is prepared by mixing intermediate product 3 and methanol at a volume ratio of 0.01 mol: 30 mL.

[0049] Modified graphene oxide is prepared by the following steps:

[0050] Step B1: Isopropanol and bromopropane are mixed, and pyridine-2,6-dicarboxaldehyde solution is added dropwise with stirring. The mixture is refluxed at 90°C for 48 hours. After the reaction is complete, the mixture is rotary evaporated, and the resulting product is added dropwise to ethyl acetate. The precipitate is then washed, filtered, and dried under vacuum to obtain pyridine dicarboxaldehyde bromide. The ratio of isopropanol, bromopropane, pyridine-2,6-dicarboxaldehyde solution, and ethyl acetate is 120 mL: 0.12 mol: 80 mL: 350 mL. The pyridine-2,6-dicarboxaldehyde solution is prepared by mixing pyridine-2,6-dicarboxaldehyde and isopropanol at a ratio of 0.1 mol: 80 mL.

[0051] Step B2: Mix formaldehyde pyridine bromide and potassium hexafluorophosphate, add acetonitrile, and reflux at 70°C for 48 hours under an argon atmosphere. Filter, rotary evaporate, wash, and vacuum dry the resulting product to obtain formaldehyde pyridine hexafluorophosphate. The ratio of formaldehyde pyridine bromide, potassium hexafluorophosphate, and acetonitrile is 0.03 mol: 0.00375 mol: 50 mL.

[0052] Step B3: Mix graphene oxide and anhydrous ethanol, sonicate for 30 min, add 1,3,5-triaminobenzene, stir, then add diformaldehyde pyridine hexafluorophosphate solution dropwise, reflux at 80℃ for 6 h, cool to room temperature, filter, wash three times with 60℃ ethanol solution, and dry to obtain modified graphene oxide. The ratio of graphene oxide, anhydrous ethanol, 1,3,5-triaminobenzene, diformaldehyde pyridine hexafluorophosphate solution and 60℃ ethanol solution is 0.4 g: 40 mL: 0.005 mol: 30 mL: 90 mL. The diformaldehyde pyridine hexafluorophosphate solution is prepared by mixing diformaldehyde pyridine hexafluorophosphate and anhydrous ethanol at a ratio of 0.01 mol: 30 mL.

[0053] Example 2: The compound antibacterial agent was prepared by the following steps:

[0054] Step A1: Mix 2-mercaptothiazole, 2,3-epoxypropyltrimethylammonium chloride, triethylamine and methanol, react at 45°C for 3.5 h, then rotary evaporate and vacuum dry to obtain the intermediate product. The molar ratio of 1,2-mercaptothiazole, 2,3-epoxypropyltrimethylammonium chloride, triethylamine and methanol is 0.3 mol: 0.36 mol: 1.17 g: 450 mL.

[0055] Step A2: Mix p-aldehyde benzoic acid, intermediate product 1, p-toluenesulfonic acid, and toluene, stir and heat to 140°C, reflux until no obvious water droplets are formed. After the reaction is complete, add ethyl acetate, wash with 10wt% sodium bicarbonate solution until pH is 8, then wash with deionized water and saturated sodium chloride solution in sequence, separate, dry, filter, distill under reduced pressure, and dry to obtain intermediate product 2. The ratio of p-aldehyde benzoic acid, intermediate product 1, p-toluenesulfonic acid, toluene, ethyl acetate, deionized water, and saturated sodium chloride solution is 0.2mol:0.19mol:0.02mol:250mL:250mL:300mL:300mL.

[0056] Step A3: Mix 2,2-dipyridinemethylamine, intermediate 2, and dichloromethane, and react at room temperature for 1 hour under argon protection. Add sodium triacetoxyborohydride and continue reacting at room temperature for 11 hours. After the reaction is complete, add deionized water, and then extract and purify to obtain intermediate 3. The ratio of intermediate 3,2,2-dipyridinemethylamine, intermediate 2, dichloromethane, sodium triacetoxyborohydride, and deionized water is 0.03 mol: 0.03 mol: 150 mL: 0.09 mol: 225 mL.

[0057] Step A4: Mix anhydrous zinc chloride and methanol, then add intermediate product 3 solution dropwise. React at room temperature under argon for 6 hours, evaporate to dryness under vacuum, extract with dichloromethane and saturated sodium chloride aqueous solution, and evaporate to dryness to obtain the composite antibacterial agent. The volume ratio of anhydrous zinc chloride, methanol, intermediate product 3 solution, dichloromethane and saturated sodium chloride aqueous solution is 0.018 mol: 75 mL: 45 mL: 250 mL: 200 mL. Intermediate product 3 solution is prepared by mixing intermediate product 3 and methanol at a volume ratio of 0.015 mol: 45 mL.

[0058] Modified graphene oxide is prepared by the following steps:

[0059] Step B1: Isopropanol and bromopropane are mixed, and pyridine-2,6-dicarboxaldehyde solution is added dropwise with stirring. The mixture is refluxed at 90°C for 48 hours. After the reaction is complete, the mixture is rotary evaporated, and the resulting product is added dropwise to ethyl acetate. The precipitate is then washed, filtered, and dried under vacuum to obtain pyridine dicarboxaldehyde bromide. The ratio of isopropanol, bromopropane, pyridine-2,6-dicarboxaldehyde solution, and ethyl acetate is 180 mL: 0.18 mol: 120 mL: 500 mL. The pyridine-2,6-dicarboxaldehyde solution is prepared by mixing pyridine-2,6-dicarboxaldehyde and isopropanol at a ratio of 0.15 mol: 120 mL.

[0060] Step B2: Mix formaldehyde pyridine bromide and potassium hexafluorophosphate, add acetonitrile, and reflux at 70°C for 48 hours under an argon atmosphere. Filter, rotary evaporate, wash, and vacuum dry the resulting product to obtain formaldehyde pyridine hexafluorophosphate. The ratio of formaldehyde pyridine bromide, potassium hexafluorophosphate, and acetonitrile is 0.045 mol: 0.00562 mol: 75 mL.

[0061] Step B3: Mix graphene oxide and anhydrous ethanol, sonicate for 30 min, add 1,3,5-triaminobenzene, stir, then add diformaldehyde pyridine hexafluorophosphate solution dropwise, reflux at 80℃ for 6 h, cool to room temperature, filter, wash three times with 60℃ ethanol solution, and dry to obtain modified graphene oxide. The ratio of graphene oxide, anhydrous ethanol, 1,3,5-triaminobenzene, diformaldehyde pyridine hexafluorophosphate solution and 60℃ ethanol solution is 0.4 g: 60 mL: 0.0075 mol: 45 mL: 135 mL. The diformaldehyde pyridine hexafluorophosphate solution is prepared by mixing diformaldehyde pyridine hexafluorophosphate and anhydrous ethanol at a ratio of 0.015 mol: 45 mL.

[0062] Example 3: The compound antibacterial agent was prepared by the following steps:

[0063] Step A1: Mix 2-mercaptothiazole, 2,3-epoxypropyltrimethylammonium chloride, triethylamine and methanol, react at 45°C for 3.5 h, then rotary evaporate and vacuum dry to obtain the intermediate product. The molar ratio of 1,2-mercaptothiazole, 2,3-epoxypropyltrimethylammonium chloride, triethylamine and methanol is 0.4 mol: 0.48 mol: 1.56 g: 600 mL.

[0064] Step A2: Mix p-aldehyde benzoic acid, intermediate product 1, p-toluenesulfonic acid, and toluene, stir and heat to 140°C, reflux until no obvious water droplets are formed. After the reaction is complete, add ethyl acetate, wash with 10wt% sodium bicarbonate solution until pH is 8, then wash with deionized water and saturated sodium chloride solution in sequence, separate, dry, filter, distill under reduced pressure, and dry to obtain intermediate product 2. The ratio of p-aldehyde benzoic acid, intermediate product 1, p-toluenesulfonic acid, toluene, ethyl acetate, deionized water, and saturated sodium chloride solution is 0.3mol:0.285mol:0.03mol:350mL:300mL:300mL;

[0065] Step A3: Mix 2,2-dipyridinemethylamine, intermediate 2, and dichloromethane, and react at room temperature for 1 hour under argon protection. Add sodium triacetoxyborohydride and continue reacting at room temperature for 11 hours. After the reaction is complete, add deionized water, and then extract and purify to obtain intermediate 3. The ratio of intermediate 3,2,2-dipyridinemethylamine, intermediate 2, dichloromethane, sodium triacetoxyborohydride, and deionized water is 0.04 mol: 0.04 mol: 200 mL: 0.12 mol: 300 mL.

[0066] Step A4: Mix anhydrous zinc chloride and methanol, then add intermediate product 3 solution dropwise. React at room temperature under argon for 6 hours, evaporate to dryness under vacuum, extract with dichloromethane and saturated sodium chloride aqueous solution, and evaporate to dryness to obtain the composite antibacterial agent. The ratio of anhydrous zinc chloride, methanol, intermediate product 3 solution, dichloromethane and saturated sodium chloride aqueous solution is 0.024 mol: 100 mL: 60 mL: 300 mL: 250 mL. Intermediate product 3 solution is prepared by mixing intermediate product 3 and methanol at a ratio of 0.02 mol: 60 mL.

[0067] Modified graphene oxide is prepared by the following steps:

[0068] Step B1: Isopropanol and bromopropane were mixed, and pyridine-2,6-dicarboxaldehyde solution was added dropwise with stirring. The mixture was refluxed at 90°C for 48 hours. After the reaction was completed, the mixture was rotary evaporated, and the resulting product was added dropwise to ethyl acetate. The precipitate was precipitated, washed, filtered, and dried under vacuum to obtain pyridine dicarboxaldehyde bromide. The ratio of isopropanol, bromopropane, pyridine-2,6-dicarboxaldehyde solution, and ethyl acetate was 240 mL: 0.24 mol: 160 mL: 600 mL. The pyridine-2,6-dicarboxaldehyde solution was prepared by mixing pyridine-2,6-dicarboxaldehyde and isopropanol at a ratio of 0.2 mol: 160 mL.

[0069] Step B2: Mix formaldehyde pyridine bromide and potassium hexafluorophosphate, add acetonitrile, and reflux at 70°C for 48 hours under an argon atmosphere. Filter, rotary evaporate, wash, and vacuum dry the resulting product to obtain formaldehyde pyridine hexafluorophosphate. The ratio of formaldehyde pyridine bromide, potassium hexafluorophosphate, and acetonitrile is 0.06 mol: 0.075 mol: 100 mL.

[0070] Step B3: Mix graphene oxide and anhydrous ethanol, sonicate for 30 min, add 1,3,5-triaminobenzene, stir, then add diformaldehyde pyridine hexafluorophosphate solution dropwise, reflux at 80℃ for 6 h, cool to room temperature, filter, wash three times with 60℃ ethanol solution, and dry to obtain modified graphene oxide. The ratio of graphene oxide, anhydrous ethanol, 1,3,5-triaminobenzene, diformaldehyde pyridine hexafluorophosphate solution and 60℃ ethanol solution is 0.4 g: 80 mL: 0.01 mol: 60 mL: 180 mL. The diformaldehyde pyridine hexafluorophosphate solution is prepared by mixing diformaldehyde pyridine hexafluorophosphate and anhydrous ethanol at a ratio of 0.02 mol: 60 mL.

[0071] Example 4: A method for preparing a stable antibacterial ink, comprising the following steps:

[0072] 25 parts acrylic acid, 15 parts isooctyl acrylate, 10 parts butyl methacrylate, 5 parts of the composite antibacterial agent prepared in Example 1, 1 part of the modified graphene oxide prepared in Example 1, 5 parts emulsifier, 200 parts deionized water, 0.1 parts azobisisopropylimidazoline, 5 parts phthalocyanine blue, and 7 parts anhydrous ethanol.

[0073] The emulsifier is prepared by compounding fatty alcohol polyoxyethylene ether and sodium dodecylbenzene sulfonate in a mass ratio of 2:1;

[0074] Step S1: Mix acrylic acid, isooctyl acrylate, butyl methacrylate, the composite antibacterial agent prepared in Example 1, the modified graphene oxide prepared in Example 1, and the emulsifier evenly and add them to deionized water. Disperse at high speed to obtain an emulsion. Then add azobisisopropylimidazoline to initiate a polymerization reaction. After the reaction is completed, a linker is obtained.

[0075] Step S2: After preliminary mixing of the binder material obtained in step S1, phthalocyanine blue, anhydrous ethanol and deionized water, add it to a single-tank planetary high-energy ball mill and grind for 2 hours with high-speed stirring to obtain water-based acrylic resin ink.

[0076] Example 5: A method for preparing a stable antibacterial ink, comprising the following steps:

[0077] 30 parts acrylic acid, 20 parts isooctyl acrylate, 13 parts butyl methacrylate, 6 parts of the composite antibacterial agent prepared in Example 2, 3 parts of modified graphene oxide prepared in Example 2, 6 parts of emulsifier, 225 parts of deionized water, 0.2 parts of azobisisopropylimidazoline, 7 parts of permanent yellow, and 9 parts of anhydrous ethanol.

[0078] The emulsifier is prepared by compounding fatty alcohol polyoxyethylene ether and sodium dodecylbenzene sulfonate in a mass ratio of 2:1;

[0079] Step S1: Mix acrylic acid, isooctyl acrylate, butyl methacrylate, the composite antibacterial agent prepared in Example 2, the modified graphene oxide prepared in Example 2, and the emulsifier evenly and add them to deionized water. Disperse at high speed to obtain an emulsion. Then add azobisisopropylimidazoline to initiate the polymerization reaction. After the reaction is completed, the connecting material is obtained.

[0080] Step S2: After preliminary mixing of the binder material, permanent yellow, anhydrous ethanol and deionized water obtained in step S1, add it to a single-tank planetary high-energy ball mill and grind for 3 hours with high-speed stirring to obtain water-based acrylic resin ink.

[0081] Example 6: A method for preparing a stable antibacterial ink, comprising the following steps:

[0082] 40 parts acrylic acid, 25 parts isooctyl acrylate, 15 parts butyl methacrylate, 8 parts of the composite antibacterial agent prepared in Example 3, 5 parts of modified graphene oxide prepared in Example 3, 8 parts of emulsifier, 250 parts of deionized water, 0.3 parts of azobisisopropylimidazoline, 10 parts of phthalocyanine green, and 10 parts of anhydrous ethanol.

[0083] The emulsifier is prepared by compounding fatty alcohol polyoxyethylene ether and sodium dodecylbenzene sulfonate in a mass ratio of 2:1;

[0084] Step S1: Mix acrylic acid, isooctyl acrylate, butyl methacrylate, the composite antibacterial agent prepared in Example 3, the modified graphene oxide prepared in Example 3, and the emulsifier evenly and add them to deionized water. Disperse at high speed to obtain an emulsion. Then add azobisisopropylimidazoline to initiate the polymerization reaction. After the reaction is completed, the connecting material is obtained.

[0085] Step S2: After preliminary mixing of the binder material obtained in step S1, phthalocyanine green, anhydrous ethanol and deionized water, the mixture is added to a single-tank planetary high-energy ball mill and ground for 5 hours with high-speed stirring to obtain water-based acrylic resin ink.

[0086] Comparative Example 1: This comparative example is an antibacterial ink. The difference between this example and Example 6 is that a quaternary ammonium salt cationic antibacterial agent is used instead of the composite antibacterial agent prepared in Example 3. All other aspects are the same.

[0087] Comparative Example 2: This comparative example is an antibacterial ink. The difference between this example and Example 6 is that graphene oxide is used instead of the modified graphene oxide prepared in Example 3. All other aspects are the same.

[0088] Comparative Example 3: This comparative example is an antibacterial ink. The difference between this example and Example 6 is that a quaternary ammonium salt cationic antibacterial agent is used instead of the composite antibacterial agent prepared in Example 3, and graphene oxide is used instead of the modified graphene oxide prepared in Example 3. All other aspects are the same.

[0089] The inks prepared in Examples 4-6 and Comparative Examples 1-3 were subjected to performance tests:

[0090] Adhesion: Adhesion was tested according to GB / T 1720-2020 standard;

[0091] Antibacterial rate: The antibacterial performance was determined according to the national standard GB / T 21866-2008 "Determination of antibacterial properties and antibacterial effects of antibacterial coatings (films)";

[0092] Antibacterial stability: The antibacterial properties of the sample before and after heat aging were determined by placing it in an environment of 150℃ for 48 hours, in accordance with the national standard GB / T 21866-2008.

[0093] Antistatic properties: The surface resistance of the ink coating was measured using a CA36 high-resistivity meter to determine its antistatic properties.

[0094] The test results are shown in Table 1:

[0095] Table 1: Performance Test Results

[0096]

[0097] As shown in Table 1, the antibacterial ink prepared by this invention exhibits excellent adhesion. The ink in Comparative Example 2 showed decreased adhesion, presumably because the unmodified graphene oxide was easily and unevenly dispersed in the ink, leading to decreased adhesion. Comparative Example 1 and Example 6 demonstrate that the composite antibacterial agent prepared by this invention possesses excellent antibacterial properties and stability, with performance far superior to that of a single antibacterial agent. Comparative Example 2 and Example 6 show that graphene oxide modification improves conductivity, reduces surface resistivity, and enhances antistatic properties. This indicates that the stable antibacterial ink prepared by this invention possesses excellent antibacterial stability and antistatic properties.

[0098] The above content is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the scope defined by the inventive concept, they should all fall within the protection scope of the present invention.

Claims

1. A stable antibacterial ink, characterized by, The raw materials include the following parts by weight: 25-40 parts acrylic acid, 15-25 parts isooctyl acrylate, 10-15 parts butyl methacrylate, 5-8 parts composite antibacterial agent, 1-5 parts modified graphene oxide, 5-8 parts emulsifier, 200-250 parts deionized water, 0.1-0.3 parts initiator, 5-10 parts pigment, and 7-10 parts anhydrous ethanol; The composite antibacterial agent is prepared by the following steps: Step A1: Mix 2-mercaptothiazole, 2,3-epoxypropyltrimethylammonium chloride, triethylamine and methanol, react at 45°C for 3.5 h, then rotary evaporate and vacuum dry to obtain intermediate product 1; Step A2: Mix p-aldehyde benzoic acid, intermediate product 1, p-toluenesulfonic acid and toluene, stir and heat to 140°C, reflux until no obvious water droplets are formed, after the reaction is complete, add ethyl acetate, wash with 10wt% sodium bicarbonate solution until pH is 8, then wash with deionized water and saturated sodium chloride solution in sequence, separate, dry, filter, distill under reduced pressure and dry to obtain intermediate product 2. Step A3: Mix 2,2-dipyridinemethylamine, intermediate 2 and dichloromethane, and react at room temperature for 1 hour under argon protection. Add sodium triacetoxyborohydride and continue the reaction at room temperature for 11 hours. After the reaction is completed, add deionized water, and then extract and purify to obtain intermediate 3. Step A4: Mix anhydrous zinc chloride and methanol, then add intermediate product 3 solution dropwise, react at room temperature under argon for 6 hours, evaporate to dryness under vacuum, extract with dichloromethane and saturated sodium chloride aqueous solution, and evaporate to dryness to obtain composite antibacterial agent.

2. The stable antimicrobial ink according to claim 1, wherein In step A1, the ratio of 2-mercaptothiazole, 2,3-epoxypropyltrimethylammonium chloride, triethylamine, and methanol is 0.2-0.4 mol: 0.24-0.48 mol: 0.78-1.56 g: 300-600 mL.

3. The stable antimicrobial ink of claim 1, wherein In step A2, the ratio of the amounts of p-aldehyde benzoic acid, intermediate product 1, p-toluenesulfonic acid, toluene, ethyl acetate, deionized water, and saturated sodium chloride solution is 0.1-0.3 mol: 0.095-0.285 mol: 0.01-0.03 mol: 150-350 mL: 200-300 mL: 300 mL: 300 mL.

4. The stable antimicrobial ink of claim 1, wherein In step A3, the ratio of 2,2-dipyridinemethylamine, intermediate product 2, dichloromethane, sodium triacetoxyborohydride, and deionized water is 0.02-0.04 mol: 0.02-0.04 mol: 100-200 mL: 0.06-0.12 mol: 150-300 mL.

5. The stable antimicrobial ink of claim 1, wherein In step A4, the ratio of anhydrous zinc chloride, methanol, intermediate product 3 solution, dichloromethane, and saturated sodium chloride aqueous solution is 0.012-0.024 mol: 50-100 mL: 30-60 mL: 200-300 mL: 150-250 mL. The intermediate product 3 solution is prepared by mixing intermediate product 3 and methanol in a ratio of 0.01-0.02 mol: 30-60 mL.

6. The stable antibacterial ink according to claim 1, characterized in that, The modified graphene oxide is prepared by the following steps: Step B1: Mix isopropanol and bromopropane, add pyridine-2,6-dicarboxaldehyde solution dropwise while stirring, reflux at 90°C for 48 h, after the reaction is complete, rotary evaporate, add the obtained product dropwise to ethyl acetate, precipitate, wash, filter, and vacuum dry to obtain dicarboxaldehyde pyridine bromide. Step B2: Mix diformaldehyde pyridine bromide and potassium hexafluorophosphate, add acetonitrile, and reflux at 70°C for 48 hours under an argon atmosphere. Filter, rotary evaporate, wash, and vacuum dry the product to obtain diformaldehyde pyridine hexafluorophosphate. Step B3: Mix graphene oxide and anhydrous ethanol, sonicate for 30 min, add 1,3,5-triaminobenzene, stir, then add diformaldehyde pyridine hexafluorophosphate solution dropwise, reflux at 80 °C for 6 h, cool to room temperature, filter, wash three times with 60 °C ethanol solution, and dry to obtain modified graphene oxide.

7. The stable antibacterial ink according to claim 6, characterized in that, In step B1, the ratio of isopropanol, bromopropane, pyridine-2,6-dicarboxaldehyde solution, and ethyl acetate is 120-240 mL : 0.12-0.24 mol : 80-160 mL : 350-600 mL. The pyridine-2,6-dicarboxaldehyde solution is prepared by mixing pyridine-2,6-dicarboxaldehyde and isopropanol in a ratio of 0.1-0.2 mol : 80-160 mL.

8. The stable antibacterial ink according to claim 6, characterized in that, In step B2, the ratio of diformaldehyde pyridine bromide, potassium hexafluorophosphate, and acetonitrile is 0.03-0.06 mol: 0.00375-0.075 mol: 50-100 mL.

9. The stable antibacterial ink according to claim 6, characterized in that, In step B3, the ratio of graphene oxide, anhydrous ethanol, 1,3,5-triaminobenzene, diformaldehyde pyridine hexafluorophosphate solution, and 60°C ethanol solution is 0.4g:40-80mL:0.005-0.01mol:30-60mL:90-180mL. The diformaldehyde pyridine hexafluorophosphate solution is prepared by mixing diformaldehyde pyridine hexafluorophosphate and anhydrous ethanol at a ratio of 0.01-0.02mol:30-60mL.

10. A method for preparing the stable antibacterial ink according to any one of claims 1-9, characterized in that, The method for preparing the stabilized antibacterial ink includes the following steps: Step S1: Mix acrylic acid, isooctyl acrylate, butyl methacrylate, composite antibacterial agent, modified graphene oxide and emulsifier evenly and add to deionized water. Disperse at high speed to obtain an emulsion. Then add an initiator to initiate the polymerization reaction. After the reaction is completed, the binder is obtained. Step S2: After preliminary mixing of the binder, pigment, anhydrous ethanol and deionized water obtained in step S1, add them to a single-tank planetary high-energy ball mill and grind for 2-5 hours with high-speed stirring to obtain water-based acrylic resin ink.

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