Antimicrobial composition as well as preparation method and application thereof

Abstract

The invention relates to an antimicrobial composition as well as a preparation method and application thereof. The present invention relates to an antimicrobial composition comprising at least one silver compound, at least one organic compounding agent and one or more bases wherein the organic compounding agent has the structure of the following formula I wherein R1 is independently hydrogen, linear or branched C1-C5 alkyl, or amino optionally substituted by C1-C5 alkyl, R2 is independently linear C1-C5 alkylene, R3 is independently hydrogen, linear or branched C1-C5 alkyl, or amino optionally substituted by C1-C5 alkyl, and R4 is independently hydrogen, linear or branched C1-C5 alkyl, or amino optionally substituted by C1-C5 alkyl. And R3 is independently hydrogen, a linear or branched C1-C5 alkyl group, or a linear or branched C2-C5 alkyl group substituted by a carboxyl group, optionally substituted by a C1-C5 alkyl group, and R3 is independently hydrogen, a linear or branched C1-C5 alkyl group, or a linear or branched C2-C5 alkyl group. When formulated as an aqueous composition, the composition has good physical stability and even good color stability, in particular heat and / or light resistance, has a pleasant aesthetic feeling to the consumer, and is non-toxic and low-cost, especially useful in home care compositions, personal care compositions and industrial cleaning compositions.

Description

Technical Field

[0001] This invention relates to antimicrobial compositions, particularly to an antimicrobial composition comprising a silver compound, especially an aqueous antimicrobial composition, as well as its preparation method and its application in household care compositions, personal care compositions and industrial cleaning compositions. Background Technology

[0002] Silver-containing compositions are well-known broad-spectrum antimicrobial agents used in general applications in medical and daily care products. However, high concentrations of silver compounds in aqueous forms, even those chelating silver ions, are prone to instability upon exposure to alkaline environments, heat, and light. This can manifest as significant discoloration of the solution, such as yellowing, reddening, or even turning brownish-black, and the formation of brown, gray, or black particles that readily aggregate and / or settle. This poor stability not only reduces the antimicrobial efficacy of aqueous formulations but also provides an unpleasant aesthetic experience for consumers. Furthermore, most silver oxides and salts have poor solubility in water. The antimicrobial efficacy of silver-based antimicrobial agents tends to diminish over time, especially in the alkaline environment of cleaning / washing compositions.

[0003] Karl Wilhelm von Negri The "oligodynamic effect" of silver was first described in 1893, in which silver ions and silver-based compounds exhibit powerful antimicrobial properties even at extremely low concentrations. Once silver ions are released from silver metal or particles into the environment, they interact with microorganisms such as bacteria, viruses, and fungi, disrupting key molecular structures and processes. This leads to the inactivation and death of the microorganisms. This ability of trace amounts of silver ions to exert their antimicrobial effect was initially termed the "oligodynamic effect," and it has been used in various antimicrobial applications requiring sustained microbial control at the lowest possible concentrations of silver compounds.

[0004] US6939566B2 discloses a microbial formulation comprising at least one disinfectant and a complex of the formula RM, wherein R is at least one organic chelating moiety, M is at least one metal ion, and wherein R is present in at least an equimolar amount based on the amount of M, and M has microbial activity against at least one microorganism, wherein the at least one organic chelating moiety is an amino acid, wherein the amino acid is selected to form a complex with M at a pH of 2 or lower, wherein the amino acid includes a double-bonded oxygen, wherein the double-bonded oxygen of the amino acid complexes with M at a pH of 2 or lower, and wherein the disinfectant and the complex are different, and wherein the complex is a solid in the formulation. The amino acid used is an α-amino acid. The formulation is preferably a concentrate in gel or solid form. In the examples, soluble silver nitrate and α-amino acid are used to form a complex that is an insoluble precipitate visible to the naked eye, and hydrogen peroxide is additionally used as a disinfectant in combination with the above complex in the formulation for the preservation of flowers and plants.

[0005] US8637088B2 discloses an antimicrobial composition containing soluble silver dihydrogen citrate, which serves as a source of soluble silver ions and is used together with complexing and chelating agents that help stabilize silver ions, thereby allowing antimicrobial efficacy to be maintained even at neutral or alkaline pH values. The complexing agents used are alkanolamines, such as monoethanolamine and amino alcohols, to prevent silver ion precipitation. Furthermore, chelating agents such as α-amino acids like glutamic acid or EDTA provide further silver ion stabilization. The disclosed formulations at pH values ​​above 6 exhibit potent antimicrobial activity. This literature does not address long-term storage stability or color stability.

[0006] US10093885B2 or EP3099772B1 discloses an aqueous composition containing a microdynamic metal, a chelating agent, an organic acid, and less than 1% by weight of free base. The stable aqueous antimicrobial composition can be made from a wide range of silver compounds and exhibits good anti-precipitation stability, with improved red discoloration. The chelating agent used is selected from ethylenediaminetetraacetic acid (EDTA), ethylenediaminedisuccinate (EDDS), N,N-bis(carboxymethyl)glutamic acid (GLDA), diethylenetriaminepentaacetic acid (DTPA), nitrilotriacetic acid (NTA), or ethanolic diglycine (EDG). Chelating agents are typically used in the form of their salts with the metal. This literature found that the stability of alkaline aqueous compositions containing microdynamic metals and the control of discoloration tendency can be improved by adding an organic acid to reduce the free base content of the composition. Examples demonstrate that precipitation occurred before and after 3 months of storage without the addition of organic fatty acids or their salts. This literature does not address light stability or the improvement of yellow discoloration.

[0007] WO2022184657A1 discloses an aqueous antimicrobial composition comprising a silver compound, amino acids, and fatty acids. The composition exhibits potent antimicrobial activity and is stable over a wide pH range. The amino acids specifically listed and preferably used in this document are strongly basic α-amino acids, which require stabilization with fatty acids. This composition can be incorporated into personal care and home care products. The document mentions that combining the silver compound with fatty acids and amino acids prevents discoloration of the composition due to UV radiation and / or pH changes and improves stability. Examples show that personal care and home care compositions containing the antimicrobial composition remain stable for three months at room temperature and under accelerated stabilization conditions (temperature 40 ± 2 °C and humidity 75 ± 5%), with no change in appearance. Color results range from colorless to yellow, but no further investigation was conducted on the improvement of yellow discoloration, nor was the lightfastness or sunlight resistance of the color specifically investigated.

[0008] Therefore, there is a continued need for antimicrobial compositions with good stability to meet consumers' aesthetic requirements for product appearance, especially color, and for compositions that are non-toxic and low-cost, thus meeting the requirements of many applications, especially in the personal and home care field. Summary of the Invention Invention Overview

[0010] In view of the problems in the prior art, the object of the present invention is to provide an antimicrobial composition with good stability, which, when formulated into an aqueous composition, exhibits good physical stability and even good color stability, without agglomeration or precipitation even after long-term storage or even heat storage, and even with good heat resistance and / or light resistance in terms of color, especially showing improved resistance to yellowing, which is aesthetically pleasing to consumers and is non-toxic and low-cost, thus meeting the requirements of many applications, especially in personal and home care and industrial cleaning fields.

[0011] Another object of the present invention is to provide a method for preparing the antimicrobial composition, which is simple, easy to implement, low in cost, and can be scaled up for commercial production.

[0012] Another object of the present invention is to provide the use of the antimicrobial composition in personal care compositions, household care compositions, industrial cleaning compositions, coatings or crop applications, preferably as an antimicrobial agent therein.

[0013] Accordingly, an object of the present invention is also to provide personal care compositions, home care compositions and industrial cleaning compositions comprising the antimicrobial compositions described herein.

[0014] Unexpectedly, it was discovered that by using a compound containing a carboxyl group and at least one amino group, and having a carbon number greater than or equal to 2 (i.e., R2 in Formula I has a carbon number greater than or equal to 1) as an organic complexing agent and adjusting the pH with an alkali, the organic complexing agent can form a stable complex with the silver compound and can form a stable colloidal dispersion in water, thereby preparing a silver compound-based antimicrobial composition with good physical stability and even good light and / or heat resistance color stability, thus achieving the above-mentioned objective.

[0015] Therefore, in a first aspect, the present invention provides an antimicrobial composition comprising at least one silver compound, at least one organic complexing agent, and one or more bases, wherein the organic complexing agent has the structure of formula I:

[0016]

[0017] in

[0018] R1 is independently hydrogen, a linear or branched C1-C5 alkyl group, or an amino group optionally substituted with a C1-C5 alkyl group, and

[0019] R2 is independently a linear C1-C5 alkylene group, which may optionally be substituted with a C1-C5 alkyl group;

[0020] R3 is independently hydrogen, a linear or branched C1-C5 alkyl group, or a linear or branched C2-C5 alkyl group substituted with a carboxyl group.

[0021] In another aspect, the present invention provides a method for preparing the antimicrobial composition, wherein all components used to prepare the composition are mixed.

[0022] In another aspect, the present invention provides the use of the antimicrobial composition in personal care compositions, household care compositions, industrial cleaning compositions, coatings, or agricultural applications.

[0023] In another aspect, the present invention provides personal care, home care, and industrial cleaning compositions comprising the said antimicrobial compositions.

[0024] Other aspects provided by this invention will become apparent from the following description. Invention Details

[0026] As used herein, the term "antimicrobial" refers to the act of killing or inhibiting the growth of microorganisms such as bacteria, fungi, or viruses. Antimicrobial compositions or agents can kill microorganisms (microbiocic) or prevent their growth (microbial inhibitory).

[0027] The antimicrobial composition of the present invention comprises at least one silver compound, at least one organic complexing agent of formula I, and one or more bases.

[0028] In a preferred embodiment, the antimicrobial composition contains water and is therefore an aqueous antimicrobial composition.

[0029] At room temperature or elevated temperatures, the silver compound in the aqueous antimicrobial composition can form a silver complex with an organic complexing agent. This silver complex is insoluble in water and forms a stable colloidal dispersion. The dispersion has an absolute zeta potential greater than 20 mV and may contain silver complex nanoparticles with a hydrodynamic diameter less than 500 nm, particularly less than 300 nm, thus constituting a stable colloidal dispersion.

[0030] Such antimicrobial compositions are photo and / or thermally stable for at least 15 days, preferably at least 20 days, and particularly at least 60 days, at room temperature and elevated temperatures without precipitation or agglomeration, and may even exhibit lower APHA chromaticity values, demonstrating an improvement in resistance to yellowing.

[0031] In the antimicrobial composition, the molar ratio of the silver compound to the organic complexing agent can be from 1:1.5 to 1:60, preferably from 1:6 to 1:48.

[0032] In a preferred embodiment, the aqueous antimicrobial composition comprises or is composed of the following substances:

[0033] -0.01% to 2% by weight, preferably 0.05% to 1% by weight, particularly preferably 0.05% to 0.5% by weight of at least one silver compound;

[0034] -0.2 wt% to 30 wt%, preferably 0.2 wt% to 10 wt%, more preferably 0.2 wt% to 4 wt%, of at least one organic complexing agent, wherein the organic complexing agent has the structure of formula I:

[0035]

[0036] in

[0037] R1 is independently hydrogen, a linear or branched C1-C5 alkyl group, or an amino group optionally substituted with a C1-C5 alkyl group, and

[0038] R2 is independently a linear C1-C5 alkylene, which is optionally substituted with a C1-C5 alkyl group; preferably, a linear C2-C5 alkylene group optionally substituted with a C1-C5 alkyl group.

[0039] R3 is independently hydrogen, a linear or branched C1-C5 alkyl group, or a linear or branched C2-C5 alkyl group substituted with a carboxyl group;

[0040] - One or more bases, in an amount such that the pH of the composition is adjusted to between 7 and 12, preferably between 8 and 12, particularly preferably between 9 and 12; and

[0041] -water.

[0042] In a particularly preferred embodiment, the aqueous antimicrobial composition comprises or is composed of the following substances:

[0043] -0.01% to 2% by weight, preferably 0.05% to 1% by weight, particularly preferably 0.05% to 0.5% by weight of a silver compound selected from silver oxide;

[0044] -0.2% to 30% by weight, preferably 0.2% to 10% by weight, more preferably 0.2% to 4% by weight of at least one organic complexing agent, said organic complexing agent being selected from 3-aminobutyric acid, 4-aminobutyric acid, 5-aminopentanoic acid, 6-aminohexanoic acid and mixtures thereof;

[0045] - One or more bases, selected from sodium hydroxide and potassium hydroxide, wherein the amount of base used is such that the pH of the composition is adjusted to between 8 and 12, preferably between 9 and 12; and

[0046] -water.

[0047] In one embodiment, the composition of the present invention may be a concentrate in gel or solid form that is anhydrous or contains a small amount of water, and water can be added on-site at the time of use to formulate an aqueous antimicrobial composition.

[0048] In this article, room temperature refers to 25±2℃.

[0049] silver compounds

[0050] The antimicrobial composition of the present invention comprises at least one silver compound.

[0051] Suitable silver compounds that can be used include, but are not limited to, silver oxide, silver halides such as silver chloride, silver iodide, silver bromide, silver fluoride, silver citrate, silver acetate, silver nitrate, silver carbonate, silver sulfate, silver sulfide, silver phosphate, silver benzoate, silver salicylate, and mixtures thereof. In a preferred embodiment, silver oxide is used as the silver compound.

[0052] The silver compound used initially can be in powder form. In aqueous antimicrobial compositions, the silver compound reacts with organic complexing agents to form a stable colloidal dispersion containing nanoparticles with hydrodynamic diameters less than 500 nm, particularly less than 300 nm.

[0053] In the aqueous antimicrobial composition, the content of the silver compound can be 0.01 wt% to 2 wt%, preferably 0.05 wt% to 1 wt%, particularly preferably 0.05 wt% to 0.5 wt%, based on the total weight of the aqueous antimicrobial composition.

[0054] Organic compounding agents

[0055] A key aspect of this invention is that the antimicrobial composition comprises at least one organic complexing agent of formula I.

[0056]

[0057] In Formula I, the number of carbon atoms in R2 must be greater than or equal to 1, i.e., it is not a single bond. Therefore, the complexing agent is not an α-amino acid, but a carboxylic acid substituted with an amino group at a position of β-, γ-, δ- or higher.

[0058] In the prior art, instability has been observed in complexes formed between α-amino acids and silver(I) compounds. In this invention, the alkyl spacer group (R2) between the carboxyl and amino groups helps to suppress precipitation, thereby improving the stability of the composition.

[0059] In addition, considering that long alkyl groups may reduce the hydrophilicity of the silver compound dispersion, it is preferred that the main chain carbon number of R2 is less than or equal to 5, that is, the carbon number of the linking group between the carboxyl group and the amino group in Formula I is less than or equal to 6.

[0060] Suitable R2 can be a linear C1-C5 alkylene group, optionally substituted with a C1-C5 alkyl group. R2 is preferably a linear C2-C5 alkylene group optionally substituted with a C1-C5 alkyl group. When the main chain carbon number of R2 is greater than or equal to 2, both heat resistance and light resistance can be improved.

[0061] In this article, C1-C5 alkyl groups include methyl, ethyl, propyl (n-propyl, isopropyl), butyl (n-butyl, isobutyl (2-methylpropyl), sec-butyl (1-methylpropyl), tert-butyl (1,1-dimethylethyl)), and pentyl (n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, tert-pentyl (1,1-dimethylpropyl), 1,2-dimethylpropyl, 2,2-dimethylpropyl, 2-ethylpropyl).

[0062] For example, R2 can be methylene, ethylene, 1,3-propylene, 1,4-butylene, 1,5-pentanediol, isopropylene (1,2-propylene), 2-methyl-1,3-propylene, 2-methyl-1,4-butylene, 3-methyl-1,4-butylene, 2,3-dimethyl-1,4-butylene, 2-ethyl-1,4-butylene, 3-ethyl-1,4-butylene, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 4-methyl-1,5-pentanediol, 2-ethyl-1,5-pentanediol, 3-ethyl-1,5-pentanediol, or 4-ethyl-1,5-pentanediol, etc.

[0063] Preferably, R2 is methylene, ethylene, 1,2-propylene, 1,3-propylene, or 1,4-butylene, more preferably ethylene, 1,2-propylene, 1,3-propylene, or 1,4-butylene.

[0064] R3 in Formula I can be hydrogen, linear or branched C1-C5 alkyl, or linear or branched C2-C5 alkyl substituted with a carboxyl group.

[0065] When R3 is a linear or branched C1-C5 alkyl group, the organic complexing agent corresponds to an N-alkyl-substituted derivative of an amino-substituted carboxylic acid, namely an N-methyl-substituted derivative, an N-ethyl-substituted derivative, an N-propyl-substituted derivative, an N-butyl-substituted derivative, or an N-pentyl-substituted derivative.

[0066] When R3 is a linear or branched C2-C5 alkyl group substituted with a carboxyl group, the organic complexing agent corresponds to an N-carboxylalkyl-substituted derivative of an amino-substituted carboxylic acid, namely an N-carboxyethyl-substituted derivative, an N-carboxypropyl-substituted derivative, an N-carboxybutyl-substituted derivative, or an N-carboxypentyl-substituted derivative.

[0067] For example, R3 can be hydrogen, methyl, ethyl, propyl (n-propyl, isopropyl), butyl (n-butyl, isobutyl (2-methylpropyl), sec-butyl (1-methylpropyl), tert-butyl (1,1-dimethylethyl)), pentyl (n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, tert-pentyl (1,1-dimethylpropyl), 1,2-dimethylpropyl, 2,2-dimethylpropyl, 2-ethylpropyl), and carboxyl-substituted ethyl, propyl, butyl, and pentyl groups, such as carboxyethyl (e.g., 1-carboxyethyl). 2-Carboxyethyl), carboxypropyl (e.g., 1-carboxypropyl, 2-carboxypropyl, 3-carboxypropyl, 1-methyl-2-carboxyethyl, etc.), carboxybutyl (e.g., 1-carboxybutyl, 2-carboxybutyl, 3-carboxybutyl, 4-carboxybutyl, 1-carboxy-2-methylpropyl, etc.), carboxypentyl (e.g., 1-carboxypentyl, 2-carboxypentyl, 3-carboxypentyl, 4-carboxypentyl, 5-carboxypentyl, 1-carboxy-2-methylbutyl, 1-carboxy-3-methylbutyl, 1-carboxy-2-ethylpropyl, etc.).

[0068] In a preferred embodiment, R3 is hydrogen.

[0069] R1 in Formula I can be hydrogen, linear or branched C1-C5 alkyl, or an amino group optionally substituted with a C1-C5 alkyl group.

[0070] For example, R1 can be hydrogen, methyl, ethyl, propyl (n-propyl, isopropyl), butyl (n-butyl, isobutyl (2-methylpropyl), sec-butyl (1-methylpropyl), tert-butyl (1,1-dimethylethyl)), pentyl (n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, tert-pentyl (1,1-dimethylpropyl), 1,2-dimethylpropyl, 2,2-dimethylpropyl, 2-ethylpropyl), amino, methylamino, dimethylamino, ethylamino, or diethylamino, etc.

[0071] In a preferred embodiment, R1 is hydrogen or methyl.

[0072] Examples of suitable organic complexing agents include, in particular, 3-aminopropionic acid, 3-aminobutyric acid, 4-aminobutyric acid, 5-aminovaleric acid, 6-aminohexanoic acid and their N-alkyl-substituted and N-carboxyalkyl-substituted derivatives, including N-methyl-substituted derivatives, N-ethyl-substituted derivatives, N-propyl-substituted derivatives, N-butyl-substituted derivatives, N-pentyl-substituted derivatives, N-carboxyethyl-substituted derivatives, N-carboxypropyl-substituted derivatives, N-carboxybutyl-substituted derivatives, N-carboxypentyl-substituted derivatives, and mixtures thereof, preferably selected from 3-aminobutyric acid, 4-aminobutyric acid, 5-aminovaleric acid and 6-aminohexanoic acid and their N-methyl-substituted and N-carboxyethyl-substituted derivatives, and mixtures thereof, more preferably selected from 3-aminobutyric acid and 4-aminobutyric acid and their N-methyl-substituted and N-carboxyethyl-substituted derivatives, and mixtures thereof.

[0073] The range of organic complexing agents can be calculated by the molar ratio between the silver compound and the complexing agent. In the aqueous antimicrobial composition, the total amount of organic complexing agents can be 0.2 wt% to 30 wt%, preferably 0.2 wt% to 10 wt%, more preferably 0.2 wt% to 4 wt%, based on the total weight of the aqueous antimicrobial composition.

[0074] alkali

[0075] The antimicrobial composition comprises one or more bases. The amount used is selected such that the pH of the composition is adjusted to be between 7 and 12, preferably between 8 and 12. A pH between 9 and 12 is particularly preferred, as this pH is higher than the pKa of the amino group in the organic complexing agent, allowing the organic complexing agent to more effectively act as a ligand to form stable complexes with the silver compound.

[0076] Common inorganic basic compounds can be used as bases. Suitable bases can be alkali metal hydroxides, such as sodium hydroxide and potassium hydroxide.

[0077] In the aqueous antimicrobial composition, the alkali exists in free form or forms a salt with an organic complexing agent.

[0078] Preferably, a free base is present in the aqueous composition. The amount of free base is preferably less than 0.5% by weight.

[0079] The free base refers to the base in the aqueous composition that is not bonded, combined or otherwise combined with other substances, such as not forming a salt with an organic complexing agent.

[0080] Water and other components

[0081] The antimicrobial composition of the present invention preferably contains water and is an aqueous dispersion.

[0082] As used in this article, the water can be softened water, deionized water, distilled water, mineral water or tap water, with deionized water being preferred.

[0083] The antimicrobial composition may contain 67.5 to 99.5% by weight, preferably 80 to 99% by weight, of water, based on the total weight of the aqueous antimicrobial composition.

[0084] The antimicrobial compositions of the present invention may additionally contain other additives commonly used in antimicrobial compositions.

[0085] For example, the antimicrobial composition may additionally contain a water-miscible or water-soluble organic solvent, such as lower alkyl alcohols, particularly C1-C5 alkyl monohydric alcohols, such as ethanol or isopropanol. The antimicrobial composition may also contain a water-soluble polyol. A water-soluble polyol is a polyol having two or more hydroxyl groups in its molecule, selected from the group consisting of: diols; triols; tetraols; pentaols; hexaols; polyol polymers; diol alkyl ethers; polyol ether esters; glycerol monoalkyl ethers; sugar alcohols and mixtures thereof.

[0086] Natural solvents, such as vegetable oils, honey, plant-derived sugar compositions and mixtures thereof, can also be used.

[0087] The antimicrobial composition may additionally include a surfactant. The surfactant may be selected from nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and zwitterionic surfactants. In one embodiment, the antimicrobial composition may be surfactant-free.

[0088] The antimicrobial composition may additionally contain fatty acids or salts thereof. The fatty acids are, for example, saturated or unsaturated, linear or branched C6 to C6 fatty acids. 22 The antimicrobial composition may be free of fatty acids and their salts. In one embodiment, the antimicrobial composition may be free of fatty acids and their salts.

[0089] Preparation method of antimicrobial composition

[0090] The antimicrobial composition of the present invention can be prepared by a method comprising the following steps: mixing all components used to prepare the composition, namely, mixing at least one silver compound, at least one organic complexing agent and one or more bases and optionally water and other optional components.

[0091] To prepare the aqueous composition, the method can be carried out at room temperature or elevated temperatures. For example, the reaction mixture can be heated after or during mixing, for example, to a temperature up to 70°C, preferably 60°C-70°C. Thereby, the mixture can react to form an aqueous dispersion containing a silver complex.

[0092] The preparation method can be carried out under normal pressure.

[0093] The aqueous dispersion formed after the reaction can be further filtered to remove insoluble impurities from the raw materials.

[0094] In one embodiment, the organic complexing agent and the base can be first dissolved in water to form a solution, and then the silver compound can be added to the solution.

[0095] In a preferred embodiment, the antimicrobial composition of the present invention can be prepared by a method comprising the following steps:

[0096] a) Dissolve the organic compounding agent and the alkali in a portion of water at room temperature or at an elevated temperature to form a solution;

[0097] b) Add a silver compound to the solution and stir to form a reaction mixture;

[0098] c) Heating the resulting reaction mixture under stirring, for example, to a temperature up to 70°C, preferably 60-70°C, to obtain a dispersion, and optionally maintaining it at that temperature for 20 minutes to 3 hours, preferably 30 minutes to 1 hour;

[0099] d) While maintaining the heating temperature, continuously add the remaining amount of water and continue stirring the reaction mixture, for example, for 1-5 hours, preferably 3 to 5 hours;

[0100] e) Optionally, filter the mixture obtained in step d).

[0101] The mixing and reaction process can be carried out in reaction vessels commonly used in laboratories or industries, such as flasks, reaction vessels, and reaction tanks.

[0102] The filtration step can be performed using filters commonly used in laboratories or industries, such as Buchner funnels, glass frit funnels, bag filters, or a combination of microporous membranes and vacuum filtration funnels.

[0103] The method for preparing the antimicrobial composition of the present invention is simple, easy to implement, low in cost, and can be scaled up for commercial production.

[0104] application

[0105] The antimicrobial composition of the present invention exhibits good physical stability when formulated as an aqueous antimicrobial composition. Even after long-term or heat storage, no aggregation or precipitation occurs in the composition. It also exhibits good color stability, particularly heat resistance, and even simultaneously good heat and light resistance, showing significant improvement in resistance to yellowing discoloration, thus meeting consumer requirements for product appearance, especially aesthetic appeal in color. The composition is non-toxic and low-cost. Therefore, the composition meets the requirements of many applications, particularly in personal and home care and industrial cleaning.

[0106] Therefore, the antimicrobial compositions of the present invention can be used in personal care compositions, household care compositions and industrial cleaning compositions, as well as in coatings and agricultural applications.

[0107] In one embodiment, the antimicrobial composition may be incorporated into personal care compositions, household care compositions, and industrial cleaning compositions to provide an antimicrobial effect. Here, the antimicrobial composition of the present invention is used as an antimicrobial agent.

[0108] Accordingly, the present invention also provides personal care, home care, and industrial cleaning compositions comprising antimicrobial compositions according to the present invention.

[0109] The personal care composition may be selected from the group consisting of: shampoos, hair and / or skin conditioning agents, shower gels, hand soaps, facial cleansers, face masks, foaming bath gels, feminine washes, body oils, cleansing milks, micellar water, makeup removers, cleansing wipes, hair masks, perfumes, liquid soaps, shaving soaps, shaving foams, cleansing foams, day creams, anti-aging creams, body lotions, body washes, body mousses, facial serums, eye creams, sunscreen lotions, sunscreen creams, face creams, aftershave lotions, pre-shave creams, hair removal creams, skin brightening gels, sunscreens, acne gels, mascaras, foundations, and makeup. Prep cream, concealer, blush, bronzer blush, BB cream, eyeliner, night cream, eyebrow gel, highlighter, lip gloss, hand sanitizer, hair oil, nail polish remover, hairspray, hair styling cream, anti-frizz hair serum, scalp treatment, hair dye, hair end repair gel, deodorant, antiperspirant, baby cream, insect repellent, hand cream, sunscreen gel, foot cream, body scrub, cellulite treatment, bar soap, skin moisturizer, lip balm, hair care products, eyeshadow, bath gel additives, body moisturizing spray, eau de toilette. Detox, lubricating gel, moisturizer, serum, toner, body lotion (aqua sorbet), emulsion, styling mousse, dry shampoo, lipstick, lip gloss, body oil, shower gel, brightening products, lip pencil, hair spray, conditioner, sunscreen cream, ointment and lipstick, preferably hand soap, shower gel, deodorant or antiperspirant.

[0110] The personal care composition may be an emulsion or a gel, preferably an oil-in-water (o / w) emulsion, cream gel or hydrogel.

[0111] The household care composition or industrial cleaning composition may be selected from the group consisting of: laundry detergents, fabric softeners, multi-purpose cleaners, household cleaners, hard surface cleaners such as floor cleaners, toilet cleaners, bathroom cleaners, kitchen cleaners, preferably dishwashing compositions, especially hand-washing dishwashing compositions, laundry detergents (in liquid form (i.e., laundry liquid) or powder form), fabric softeners, or multi-purpose cleaners.

[0112] Multi-purpose cleaners or hard surface cleaners can be used to clean surfaces such as pottery, stone, ceramic, glass, stainless steel, metal, plastic, linoleum, and wood.

[0113] In one embodiment, the multi-purpose cleaner or hard surface cleaner remains on the surface after application (“retention-type” application). In another embodiment, the multi-purpose cleaner or hard surface cleaner is removed from the surface after application and is preferably rinsed with water (“rinse-type” application).

[0114] The home care composition or industrial cleaning composition may be in liquid or gel form.

[0115] Preferably, the personal care composition, household care composition, or industrial cleaning composition may be selected from laundry detergents, fabric softeners, hard surface cleaners, dishwashing detergents, kitchen utensil cleaners, multi-purpose cleaners, hand sanitizers, shower gels, shampoos, deodorants, and antiperspirants.

[0116] The personal care composition, home care composition, or industrial cleaning composition may contain 0.00005% to 10% by weight, preferably 0.001% to 10% by weight, more preferably 0.01% to 5% by weight, and particularly preferably 0.05% to 1% by weight of an antimicrobial composition, based on the total weight of the personal care composition, home care composition, or industrial cleaning composition.

[0117] For example, in liquid detergent formulations (laundry detergent formulations), the amount of the antimicrobial composition may be up to 5% by weight, preferably 0.05% to 1% by weight.

[0118] The amount of at least one silver compound in the personal care composition, home care composition, or industrial cleaning composition is typically from 1 ppm to 10,000 ppm.

[0119] The personal care composition, home care composition, or industrial cleaning composition may contain one or more additional components.

[0120] The additional components may be selected from the following group: solvents, acidity regulators, surfactants, colorants, emulsifiers, film-forming agents, fragrances, gloss agents, wetting agents, lubricants, humectants, pigments, preservatives, skin penetration enhancers, stabilizers, thickeners and viscosity modifiers, oil components, and rheology modifiers (gelling and thickening agents).

[0121] Preferably, the additional components may be selected from the group consisting of: solvents (e.g., water, glycols, ethanol and combinations thereof), acidity regulators (e.g., triethanolamine, trisodium citrate dihydrate, alkali metal hydroxides), and surfactants (e.g., sodium lauryl ether sulfate (SLES), cocamidopropyl betaine, alkylbenzene sulfonic acid, polyethoxylated fatty alcohols).

[0122] In one embodiment, the personal care composition may contain at least one additive commonly found in the fields of cosmetics, pharmaceuticals, and dermatology. The additives may be selected from the following group: surfactants, pH adjusters, chelating agents, stabilizers, cationic polymers, buffers, waxes, film-forming agents, fatliquoring agents, refatting agents, foam stabilizers, active bioactive substances, preservatives, preservative-promoting ingredients, other antifungal substances, antidandruff agents, dyes or pigments, particulate matter, emulsifiers, abrasives, absorbents, anti-caking agents, fillers, pearlescent agents, direct dyes, fragrances or aromas, carriers, solvents or diluents, propellants, functional acids, active ingredients, skin brighteners, self-tanning agents, exfoliants, enzymes, anti-acne agents, deodorants and antiperspirants, viscosity modifiers, thickeners and gelling agents, antioxidants, astringents, sunscreens, UV filters, conditioning agents (e.g., hair conditioning agents or skin conditioning agents), emollients, moisturizers, occlusive agents, antilice agents, defoamers, flavoring agents, electrolytes, oxidizing agents, and reducing agents.

[0123] In one embodiment, the household care composition or industrial cleaning composition may optionally include conventional ingredients commonly used in detergent compositions or cleaning compositions, particularly laundry detergent compositions. Examples of the ingredients include, but are not limited to, detergent builders, bleaching agents, bleaching active compounds, bleaching activators, bleaching catalysts, photobleaching agents, dye transfer inhibitors, color protectants, anti-redeposition agents, dispersants, stabilizers, emulsifiers, fabric softeners, antistatic agents, optical brighteners, enzymes (e.g., proteases, lipases, amylases, hydrolases and / or cellulases), enzyme stabilizers (e.g., benzoamide hydrochloride, borax, boric acid, boric acid or its salts or esters, peptide aldehydes, polyols, reducing salts, succinic acid), foam conditioners, defoamers, deodorants, preservatives, disinfectants, water-soluble solvents (e.g., monopropylene glycol (MPG), glycerin, sodium cumene sulfonate, ethanol, other glycols such as dipropylene glycol, diethers and urea), fiber lubricants, anti-shrinkage agents, buffers, fragrances, processing aids, colorants, dyes, pigments, corrosion inhibitors, fillers or stabilizers. The use of polymers in household cleaning or industrial cleaning compositions, particularly in liquid laundry detergent compositions, may be advantageous for improving detergency. Preferred polymers are polyethoxylated fatty alcohols, such as polyethoxylated fatty alcohol (9EO) and polyethoxylated fatty alcohol (7EO).

[0124] In a preferred embodiment, the personal care composition, household care composition, or industrial cleaning composition may be selected from laundry detergents (e.g., laundry liquid), hand soaps, shower gels, and shampoos. These compositions may contain, in addition to the antimicrobial composition of the present invention, one or more ingredients selected from: solvents, acidity regulators, and surfactants, particularly one or more ingredients selected from: water, sodium lauryl ether sulfate (SLES), cocamidopropyl betaine, alkylbenzene sulfonic acid, polyethoxylated fatty alcohols (e.g., polyethoxylated fatty alcohol (9EO) and polyethoxylated fatty alcohol (7EO)), triethanolamine, trisodium citrate dihydrate, and sodium hydroxide.

[0125] The antimicrobial composition according to the invention exhibits improved physical stability and even color stability to heat and / or light when formulated into an aqueous composition, and personal care, household care and industrial cleaning compositions prepared from the antimicrobial composition can exhibit effective antimicrobial effects, meeting or even exceeding the requirements of standard products.

[0126] Alternatively, at least one silver compound, at least one organic complexing agent, and one or more bases may be combined in a combination form without being pre-formulated into a composition or an aqueous composition, and used directly in personal care compositions, household care compositions, industrial cleaning compositions, coatings, or agricultural applications, preferably in laundry detergents, fabric softeners, hard surface cleaners, dishwashing detergents, kitchen utensil cleaners, multi-purpose cleaners, hand soaps, shower gels, shampoos, deodorants, or antiperspirants. Such uses also constitute a part of this invention. Detailed Implementation

[0127] The invention is further illustrated below with reference to embodiments, but the invention is not limited to these embodiments.

[0128] 1. Raw materials

[0129]

[0130] 2. Preparation of antimicrobial compositions

[0131] First, the organic complexing agent and base, in the weight ratios shown in Table 1 below, are added to the reaction vessel at room temperature. Then, an appropriate amount of deionized water is added, and the mixture is stirred until the solute is completely dissolved.

[0132] Then, silver oxide in the weight ratios shown in Table 1 was added to the reaction vessel at room temperature, along with an appropriate amount of deionized water. The resulting mixture was heated to 60°C and maintained with stirring for 30 minutes, until the mixture became clear.

[0133] While maintaining a temperature of 60°C, the remaining amount of deionized water was continuously added to the reaction vessel, and the mixture was stirred for 3 hours.

[0134] The final dispersion was filtered through a combination of a 0.45 μm microporous membrane and a vacuum funnel to remove insoluble impurities from the silver oxide, thus obtaining the final antimicrobial composition.

[0135] The silver oxide content in the resulting antimicrobial composition can be determined by digestion with nitric acid followed by titration of silver ions. Since high-purity silver oxide is used in the examples, the percentage of silver oxide in the raw materials is considered as the percentage of silver oxide in the product.

[0136]

[0137] 3. Performance testing of antimicrobial compositions

[0138] 3.1 APHA Colorimetric and Stability Test

[0139] APHA colorimetry, or the Platinum Cobalt (Pt / Co) scale, is a color standard named after the American Public Health Association (APHA) and defined by ASTM D1209. Sometimes referred to as the "yellowness index," it is used to assess the quality of colorless to pale yellow transparent liquids. This index is highly correlated with the appearance of the dispersion. As yellowness increases, the dispersion becomes darker and is considered an unpleasant appearance to consumers.

[0140] The APHA chromaticity of the antimicrobial compositions was determined for samples from all embodiments after one month of heat storage (in the dark) at 50°C and exposure to sunlight (normal daylight, room temperature). APHA chromaticity was measured at room temperature using a 10 mm cuvette with a Lovibond PFXi 195 / 1. These results indicate the samples' tolerance to heat and light exposure.

[0141] In addition, the antimicrobial composition samples of Examples 1-10 were stored at 50°C, and the duration from the start of storage to the first day when precipitation was visible to the naked eye was recorded. This duration indicates the physical stability of the antimicrobial composition.

[0142] The results of the APHA colorimetric and stability test durations for all samples are shown in Table 2.

[0143] Table 2: Duration of stability test and results of APHA chromaticity after 1 month of storage

[0144]

[0145] *APHA colorimetry is measured only for clear dispersions in which no precipitate is observed.

[0146] NA: Not applicable.

[0147] Table 2 shows that the composition was also successfully prepared using monosodium glutamate in Example 1, and the freshly prepared sample was clear and colorless. However, the composition using this α-amino acid exhibited low heat resistance and precipitation occurred after 14 days of heat storage.

[0148] In Example 2, the chelating agent N,N-bis(carboxymethyl)glutamic acid mentioned in the prior art was used together with sodium glutamate. The results showed that the stability of the composition was further significantly reduced compared to Example 1.

[0149] In Example 3, the composition using an organic complexing agent containing an amino group and a carboxyl group linked by an ethyl group (R2 = methylene) showed improved thermal stability, but poor lightfastness.

[0150] Examples 4 and 5 demonstrate the beneficial effects of using organic complexing agents in which the R2 main chain has more than 1 carbon atom. They improve the physical stability and color stability of the aqueous antimicrobial composition to both heat and sunlight. In particular, the samples of Examples 4 and 5 exhibit excellent lightfastness. The APHA chromaticity of the sample of Example 4 was only 13 after one month of sunlight exposure, and a further measurement of its APHA chromaticity after six months showed a result of only 49. The sample of Example 5 showed even better resistance to photochromism.

[0151] The results of Example 6 indicate that the stability of the composition decreases with increasing carbon number of the organic complexing agent when using 8-aminooctanoic acid. Furthermore, due to the high carbon number of 8-aminooctanoic acid, the newly prepared sample in Example 6 already exhibited an APHA color value of 36.

[0152] Examples 9 and 10 show that the stability of the composition increases with increasing molar ratio between the organic complexing agent and the silver compound.

[0153] The results of Example 7 indicate that the hydroxyl side group (i.e., forming an amino alcohol structure) resulted in significantly poorer stability of the composition compared to the complexing agent used in Example 8. This demonstrates that amino alcohols negatively impact the stability of this antimicrobial composition. Conversely, the complexing agent with alkyl side groups in Example 8 resulted in compositions exhibiting excellent heat and light resistance.

[0154] The physically stable and even color-stable antimicrobial composition of the present invention not only meets the aesthetic requirements of consumers, but also improves the antimicrobial efficacy of the composition because the complex formed by silver oxide and organic complexing agent can form a stable colloidal dispersion in water, thus maintaining the concentration of the silver complex at a stable level.

[0155] 3.2 Dynamic light scattering and zeta potential

[0156] Dynamic light scattering (DLS) can be used to determine the size distribution profiles of small particles in suspensions or dispersions, or polymer molecules in solutions. An important result obtained from DLS is the intensity-weighted average hydrodynamic size, which indicates how particles interact within dispersions based on electrostatic repulsion layers.

[0157] Zeta potential is an important and easily measurable indicator of the stability of colloidal dispersions. Generally, a high zeta potential is preferred for colloidal dispersion systems, as such systems exhibit good stability.

[0158] The hydrodynamic diameters of the antimicrobial composition samples (silver complex dispersions) of Examples 1, 3-5 were determined using dynamic light scattering (DLS) with Malvern Zetasizer Pro, and the results are shown in Table 3 below.

[0159] In addition, the zeta potential of the antimicrobial composition samples of Examples 1, 3-5 was measured using a Malvern Zetasizer Pro nanoparticle size potential analyzer, and the results are shown in Table 3 below.

[0160] Based on the results of the DLVO theory and the examples in Table 3, the hydrodynamic diameter and zeta potential of the antimicrobial composition samples according to the present invention have thermal stability for more than one week.

[0161] Table 3: Hydrodynamic diameter and zeta potential of antimicrobial compositions

[0162]

[0163] As can be seen from Table 3, the absolute value of the zeta potential of all samples is greater than 20 mV, and the hydrodynamic diameter of the dispersion is less than 300 nm, which indicates that they are stable colloidal dispersions.

[0164] 4. Application testing of antimicrobial compositions

[0165] For application testing, four liquid formulations A, B, C, and D were prepared using the antimicrobial composition of Example 4, including personal care and household care products. Examples C and D are laundry detergent formulations according to the Chinese National Standard GB / T 13174-2021 (Determination of detergency and cycle of washing property for laundry detergents). Example E is a reference ratio without using the antimicrobial composition of the present invention.

[0166] Table 4 lists the detailed formulations of four samples and reference samples according to the present invention. The amount of the antimicrobial composition of Example 4 in the final formulation ranges from 0.5% to 1% by weight.

[0167] Table 4: Composition (wt%) of AE in Application Examples

[0168]

[0169] *qs stands for quantity sates, which in this case refers to the amount of sodium hydroxide needed to achieve the desired pH value. Laundry detergent needs to be adjusted to a pH value of 8.5-9.0 with sodium hydroxide.

[0170] Disinfection test (antibacterial test)

[0171] The antibacterial test was performed using test standard item 7.3 (suspension quantitative method) described in Chinese Light Industry Standard QBT2738-2012 ("Test methods for evaluating daily chemical products in antibacterial and bacteriostatic efficacy"). The antimicrobial formulations shown in Table 4 were used for this test. Detailed methods are as follows.

[0172] a. Cultivate bacteria and adjust their concentration to 1×10⁻⁶. 4 cfu / ml up to 9×10 4 Between CFU / ml.

[0173] b. Dilute the sample at a ratio of 1:100, using sterile tap water as the diluent.

[0174] c. Take 5 ml of sample diluent and place it in a sterile test tube. Let it stand at room temperature for 5 minutes.

[0175] d. Take 0.1 ml of bacterial solution and add it to a test tube containing 5 ml of sample diluent. Mix quickly and thoroughly and wait 20 minutes.

[0176] e. After 20 minutes of incubation, take 0.5 ml of the mixed solution and add it to a 4.5 ml sterile PBS tube, and mix thoroughly for 10 minutes.

[0177] f. After 10 minutes, transfer 1 ml of sample solution to a sterile petri dish, and inoculate two sterile petri dishes for each sample. Pour in 15 ml of nutrient agar medium, and rotate the petri dish at 40-45°C to distribute the agar evenly. After the agar solidifies, quickly invert the petri dish.

[0178] g. Place the coated petri dishes in an incubator at 35°C and incubate for 48 hours.

[0179] h. Record the number of recovered colonies and calculate the inhibition rate.

[0180] The evaluation criteria for antibacterial testing are as follows. The antibacterial rate R can be calculated as follows.

[0181] R(%) = (AB) / A × 100%

[0182] Where A represents the average staining count of the control sample, and B is the average staining count of the test sample. If the inhibition rate is ≥90%, the product is considered to have antibacterial effect; if the inhibition rate is <50%, the product is considered to have no antibacterial effect.

[0183] Antibacterial tests were performed on samples from application examples A to E, and the results are shown in Table 5 below.

[0184] Table 5: Antimicrobial activity results of personal care or household care formulations (laundry detergent formulations) using AE in application examples.

[0185]

[0186] As can be seen from Table 5, all samples according to the present invention achieved a reduction rate of more than 90% against both Staphylococcus aureus and Escherichia coli, which can be considered as having an effective antibacterial effect. In contrast, the GB standard laundry detergent (Example E) without the antimicrobial composition according to the present invention, used as a reference, showed no antibacterial effect against Escherichia coli.

Claims

1. An antimicrobial composition comprising at least one silver compound, at least one organic complexing agent, and one or more bases, wherein the organic complexing agent has the structure of formula I: in R1 is independently hydrogen, a linear or branched C1-C5 alkyl group, or an amino group optionally substituted with a C1-C5 alkyl group, and R2 is independently a linear C1-C5 alkylene, which is optionally substituted with a C1-C5 alkyl group, preferably a linear C2-C5 alkylene group optionally substituted with a C1-C5 alkyl group; R3 is independently hydrogen, a linear or branched C1-C5 alkyl group, or a linear or branched C2-C5 alkyl group substituted with a carboxyl group.

2. The antimicrobial composition according to claim 1, wherein the molar ratio of the silver compound to the organic complexing agent is 1:1.5 to 1:60, preferably 1:6 to 1:

48.

3. The antimicrobial composition according to claim 1 or 2, wherein the silver compound is selected from silver oxide, silver halide, silver citrate, silver acetate, silver nitrate, silver carbonate, silver sulfate, silver sulfide, silver phosphate, silver benzoate, silver salicylate, and mixtures thereof, preferably selected from silver oxide.

4. The antimicrobial composition according to any one of claims 1 to 3, wherein R2 in formula I is independently selected from methylene, ethylene, 1,3-propylene, 1,4-butylene, 1,5-pentylene, isopropylene (1,2-propylene), 2-methyl-1,3-propylene, 2-methyl-1,4-butylene, 3-methyl-1,4-butylene, 2,3-dimethyl-1,4-butylene, 2-ethyl-1,4-butylene, 3-ethyl- 1,4-Butylene, 2-Methyl-1,5-pentylene, 3-Methyl-1,5-pentylene, 4-Methyl-1,5-pentylene, 2-Ethyl-1,5-pentylene, 3-Ethyl-1,5-pentylene, and 4-Ethyl-1,5-pentylene; R2 is preferably selected from methylene, ethylene, 1,2-propylene, 1,3-propylene, and 1,4-butylene, more preferably from ethylene, 1,2-propylene, 1,3-propylene, and 1,4-butylene.

5. The antimicrobial composition according to any one of claims 1 to 4, wherein R1 in formula I is independently selected from hydrogen, methyl, ethyl, propyl (n-propyl, isopropyl), butyl (n-butyl, isobutyl, sec-butyl, tert-butyl), pentyl (n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, tert-pentyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, 2-ethylpropyl), amino, methylamino, dimethylamino, ethylamino, and diethylamino; preferably, R1 is hydrogen or methyl.

6. The antimicrobial composition according to any one of claims 1 to 5, wherein R3 in formula I is independently selected from hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, tert-pentyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, 2-ethylpropyl, and carboxyethyl, carboxypropyl, carboxybutyl and carboxypentyl, preferably hydrogen.

7. The antimicrobial composition according to any one of claims 1 to 6, wherein the organic complexing agent is selected from 3-aminopropionic acid, 3-aminobutyric acid, 4-aminobutyric acid, 5-aminovaleric acid, 6-aminohexanoic acid and their N-methyl-substituted derivatives, N-ethyl-substituted derivatives, N-propyl-substituted derivatives, N-butyl-substituted derivatives, N-pentyl-substituted derivatives, N-carboxyethyl-substituted derivatives, N-carboxypropyl-substituted derivatives, N-carboxybutyl-substituted derivatives, N-carboxypentyl-substituted derivatives, and mixtures thereof, preferably selected from 3-aminobutyric acid, 4-aminobutyric acid, 5-aminovaleric acid, 6-aminohexanoic acid and their N-methyl-substituted derivatives, N-carboxyethyl-substituted derivatives, and mixtures thereof, more preferably selected from 3-aminobutyric acid and 4-aminobutyric acid and their N-methyl-substituted derivatives, N-carboxyethyl-substituted derivatives, and mixtures thereof.

8. The antimicrobial composition according to any one of claims 1 to 7, wherein the alkali is selected from alkali metal hydroxides, preferably sodium hydroxide and potassium hydroxide.

9. The antimicrobial composition according to any one of claims 1 to 8, wherein the antimicrobial composition comprises water.

10. The antimicrobial composition according to claim 9, wherein the pH value of the composition is between 7 and 12, preferably between 8 and 12, and particularly preferably between 9 and 12.

11. The antimicrobial composition according to claim 9 or 10, wherein the content of the at least one silver compound is 0.01%-2% by weight, preferably 0.05%-1% by weight, particularly preferably 0.05%-0.5% by weight, based on the total weight of the antimicrobial composition.

12. The antimicrobial composition according to any one of claims 9 to 11, wherein the antimicrobial composition comprises 0.2 wt% to 30 wt%, preferably 0.2 wt% to 10 wt%, more preferably 0.2 wt% to 4 wt% of the at least one organic complexing agent, based on the total weight of the antimicrobial composition.

13. The antimicrobial composition according to any one of claims 9 to 12, wherein the composition comprises a free base, wherein the amount of the free base is preferably less than 0.5% by weight.

14. The antimicrobial composition according to any one of claims 9 to 13, wherein the antimicrobial composition comprises a silver complex formed by reacting the silver compound with the organic complexing agent, wherein the organic complexing agent acts as a ligand in the complex.

15. The antimicrobial composition of claim 14, wherein the antimicrobial composition is a colloidal dispersion comprising silver complex nanoparticles having a hydrodynamic diameter of less than 500 nm, particularly less than 300 nm.

16. The antimicrobial composition according to any one of claims 1-8, wherein the antimicrobial composition is a gel or a solid.

17. An aqueous antimicrobial composition, wherein the aqueous antimicrobial composition comprises or is composed of the following substances: -0.01 wt% to 2 wt%, preferably 0.05 wt% to 1 wt%, particularly preferably 0.05 wt% to 0.5 wt% of a silver compound selected from silver oxide; -0.2 wt% to 30 wt%, preferably 0.2 wt% to 10 wt%, more preferably 0.2 wt% to 4 wt%, of at least one organic complexing agent selected from 3-aminobutyric acid, 4-aminobutyric acid, 5-aminovaleric acid, 6-aminohexanoic acid and mixtures thereof; - One or more bases, selected from sodium hydroxide and potassium hydroxide, wherein the amount of base used is such that the pH of the composition is adjusted to be between 8 and 12, preferably between 9 and 12; and -water.

18. A method for preparing an antimicrobial composition according to any one of claims 1 to 17, comprising the following steps: Mix all components used to prepare the composition.

19. The method of claim 18, wherein the method is carried out at room temperature or elevated temperature, for example, heated to a temperature up to 70°C, and the mixture reacts to form an aqueous dispersion containing a silver complex.

20. The method according to claim 18 or 19, wherein the organic complexing agent and the base are first dissolved in water to form a solution, and then the silver compound is added to the solution.

21. Use of the antimicrobial composition according to any one of claims 1 to 17 in personal care compositions, household care compositions, industrial cleaning compositions, coatings or agricultural applications, preferably in laundry detergents, fabric softeners, hard surface cleaners, dishwashing detergents, kitchen utensil cleaners, multipurpose cleaners, hand sanitizers, shower gels, shampoos, deodorants or antiperspirants.

22. A household care composition comprising the antimicrobial composition according to any one of claims 1 to 17, preferably in an amount of 0.00005 to 10% by weight, more preferably 0.001 to 10% by weight, more preferably 0.01 to 5% by weight, particularly preferably 0.05% to 1% by weight, based on the total weight of the household care composition; wherein the household care composition is preferably selected from laundry detergents, fabric softeners, hard surface cleaners, dishwashing detergents, kitchen utensil cleaners, and multipurpose cleaners.

23. A personal care composition or industrial cleaning composition comprising an antimicrobial composition according to any one of claims 1 to 17, preferably in an amount of 0.00005 to 10% by weight, more preferably 0.001 to 10% by weight, more preferably 0.01 to 5% by weight, particularly preferably 0.05% to 1% by weight, based on the total weight of the personal care composition or industrial cleaning composition; wherein the personal care composition or industrial cleaning composition is preferably selected from laundry detergents, fabric softeners, hard surface cleaners, dishwashing detergents, kitchen utensil cleaners, multipurpose cleaners, hand sanitizers, shower gels, shampoos, deodorants, and antiperspirants.

24. The combination of at least one silver compound, at least one organic compounding agent, and one or more bases as defined in any one of claims 1 to 8 for use in household care compositions, personal care compositions, industrial cleaning compositions, coatings, or agricultural applications, preferably in laundry detergents, fabric softeners, hard surface cleaners, dishwashing detergents, kitchen utensil cleaners, multipurpose cleaners, hand sanitizers, shower gels, shampoos, deodorants, or antiperspirants.

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