Self-stabilizing disinfectant composition

Abstract

An antimicrobial composition containing relatively high amounts of self-stabilizing hydrogen peroxide is disclosed. The hydrogen peroxide is mixed with a stabilizer package comprising an organic sulfonic acid or salt thereof and a relatively small amount of a carboxylic acid. The composition is not only stable but also very effective against all different types of microorganisms.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefits of U.S. Provisional Application No. 63 / 514,617, filed July 20, 2023, and U.S. Provisional Application No. 63 / 648,694, filed May 17, 2024, which are expressly incorporated herein by reference in their entirety. Background Technology

[0003] Antimicrobial compositions are used in a variety of applications. Typically, antimicrobial compositions are used to destroy and / or inhibit the growth of microorganisms. Antimicrobial compositions are used, for example, to disinfect or sterilize objects in the food service industry, healthcare industry, industrial environments, and for consumer home use. In one embodiment, the antimicrobial composition is used to sterilize or disinfect surfaces, such as hard, non-porous surfaces.

[0004] Some antimicrobial compositions are known to contain hydrogen peroxide. Because it decomposes into oxygen and water and is therefore very safe to use, hydrogen peroxide has advantages and benefits as a bactericide and biocide. Another advantage of hydrogen peroxide is its broad-spectrum biocide activity against many different types of organisms.

[0005] Unfortunately, hydrogen peroxide, as an oxidant, is generally unstable in most formulations. For example, many hydrogen peroxide-based disinfectant products have a shelf life of less than one year. Therefore, when formulating disinfectant products, hydrogen peroxide is often combined with one or more stabilizers and / or converted to peracetic acid. Examples of common stabilizers used for hydrogen peroxide include phosphoric acid, 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), pyridinecarboxylic acid, pyridinedicarboxylic acid, ethylenediamine-N,N'-disuccinic acid, etc. However, these stabilizers can significantly increase the cost of the product. For example, a number of stabilizers are disclosed in U.S. Patent No. 9,321,664, which is incorporated herein by reference.

[0006] In other embodiments, hydrogen peroxide has been combined with a large amount of acetic acid to produce peracetic acid in situ. For example, U.S. Patent Publication No. 2015 / 0291520, which is incorporated herein by reference, discloses a method for producing peracetic acid by reacting acetic acid with hydrogen peroxide. However, acetic acid and peracetic acid can produce an unpleasant odor. Furthermore, peracetic acid can cause skin irritation and is not as environmentally friendly as hydrogen peroxide.

[0007] In view of the above, there is a need for antimicrobial compositions containing stable hydrogen peroxide without an unpleasant odor. There is also a need for hydrogen peroxide-based antimicrobial compositions that do not require the use of stabilizers and / or compositions in which most of the hydrogen peroxide is not converted to peracetic acid. Summary of the Invention

[0008] This disclosure generally relates to antimicrobial compositions effective against a broad range of microorganisms. For example, one particularly difficult-to-control microorganism is *Clostridium difficile*. C. difficile Clostridium difficile is a pathogen capable of causing serious gastrointestinal illness in mammals, particularly humans. In fact, it is a leading cause of hospital-acquired diarrhea and pseudomembranous colitis. The number of cases of Clostridium difficile-associated illness has been steadily increasing each year. For example, patients using antibiotics or undergoing chemotherapy are particularly susceptible to Clostridium difficile-associated illness. With the increasing frequency of illness, hospitals have become even more contaminated with Clostridium difficile spores, making infection more likely in susceptible patients. However, the antimicrobial composition disclosed herein is ideally suited for disrupting and inhibiting the growth of Clostridium difficile.

[0009] In addition to being effective against Clostridium difficile, the antimicrobial compositions disclosed herein are safe and harmless. The antimicrobial compositions can be formulated without hydrogen peroxide stabilizers. Furthermore, the antimicrobial compositions disclosed herein may contain very small amounts of acetic acid, which reduces or eliminates odor emissions.

[0010] In one embodiment, for example, this disclosure relates to an antimicrobial composition comprising an aqueous solution. The aqueous solution contains a relatively large amount of hydrogen peroxide. For example, hydrogen peroxide may be present in the aqueous solution in amounts greater than about 1% by weight, such as greater than about 2% by weight, such as greater than about 3% by weight, such as greater than about 4% by weight. The composition also contains an organic sulfonic acid. The composition may also contain C1-C 14 Carboxylic acid. Carboxylic acid may be present in the composition in amounts greater than about 0.1% by weight, such as greater than about 0.5% by weight, such as greater than about 0.8% by weight, such as greater than about 1.2% by weight, such as greater than about 1.5% by weight, such as greater than about 1.8% by weight. Carboxylic acid may be present in amounts less than about 6% by weight, such as less than about 4% by weight, such as less than about 3% by weight. Carboxylic acid may be, for example, acetic acid. The composition may have a pH less than about 4 and, when tested against Clostridium difficile according to ASTM test method E2197-11, may show a reduction of 6 log10 or greater after a 10-minute contact time, such as after a 5-minute contact time, such as after a 2-minute contact time.

[0011] As described above, the antimicrobial composition can contain an organic sulfonic acid or a salt thereof. The organic sulfonic acid or salt thereof can include a C1-C5 alkyl sulfonic acid, a sulfonated C1-C5 carboxylic acid, a substituted or unsubstituted aromatic sulfonic acid, a mono-alkyl phenyl sulfonic acid, a di-alkyl phenyl sulfonic acid, or a salt thereof, or a mixture thereof. In one aspect, the organic sulfonic acid or salt thereof includes a substituted aromatic or aliphatic sulfonic acid or salt thereof that is substituted with at least one C1-C3 alkyl group or a phenyl group. Specific examples of organic sulfonic acids that can be used in accordance with the present disclosure include methanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, or a salt thereof, or a mixture thereof. The organic sulfonic acid or salt thereof can be present in the composition in an amount of from about 0.1 wt% to about 6 wt%, including all increments of 0.1% therebetween. For example, the organic sulfonic acid or salt thereof can be present in the composition in an amount of from about 0.2 wt% to about 4 wt%. The hydrogen peroxide can be present in the composition in a weight ratio of from about 40: 1 to about 1 :2, such as from about 20: 1 to about 1 :2, such as from about 10: 1 to about 1 : 1, relative to the organic sulfonic acid or salt thereof.

[0012] As described above, the antimicrobial composition of the present disclosure can be formulated so as to not contain any hydrogen peroxide stabilizer. For example, in one aspect, the composition does not contain 1-hydroxyethylidene-1,1-diphosphonic acid. In another aspect, the composition can be free of pyridine carboxylic acids, such as picolinic acid and / or dipicolinic acid.

[0013] The composition can contain various other components. For example, the composition can contain a nonionic surfactant. In one aspect, the composition can contain an anionic surfactant. For example, anionic surfactants that can be incorporated into the composition include a linear alkyl benzene sulfonic acid or a salt thereof, an alkyl sulfate, an alkanolamide sulfate, an ethoxylated alkyl phenol, or a mixture thereof. In one embodiment, the anionic surfactant comprises sodium dodecyl benzene sulfonate.

[0014] The composition can also contain a pH adjusting agent. The pH adjusting agent can include, for example, a hydroxide such as sodium hydroxide, potassium hydroxide, ammonium hydroxide, calcium hydroxide, magnesium hydroxide, or a mixture thereof.

[0015] Surprisingly, it has been found that the compositions of the present disclosure are self-stabilizing. For example, in one aspect, the antimicrobial composition can exhibit less than 2 wt% loss of hydrogen peroxide after storage at 54°C for one week. The loss of hydrogen peroxide is determined according to the following equation:

[0016] [Initial H2O2 % - H2O2 % (after storage at 54°C)] / Initial H2O2 % x 100

[0017] In one embodiment, the antimicrobial composition can exhibit less than 5 wt%, such as less than 3 wt%, such as less than 2 wt%, such as less than about 1 wt% loss of hydrogen peroxide after storage at 54°C for two weeks.

[0018] The present disclosure also relates to methods for disinfecting a hard or soft surface. The methods include the step of contacting the surface with an antimicrobial composition as described above. The hard surface can be a surface used in the health care industry or used in the veterinary industry. Alternatively, the hard surface can include food processing equipment or food preparation services.

[0019] The antimicrobial compositions of the present disclosure can be applied to a surface using a variety of different techniques. For example, the compositions can be sprayed or otherwise applied directly to the surface. Alternatively, the antimicrobial compositions can be applied to a wiping product, which is then used to apply the composition to the surface. In this regard, the present disclosure also relates to pre-moistened wiping products containing the antimicrobial compositions as described above.

[0020] Other features and aspects of the present disclosure are discussed in greater detail below. DETAILED DESCRIPTION

[0021] It will be understood by those within the art that this discussion is merely an example of an implementation and is not intended to limit the broader aspects of the present disclosure.

[0022] Generally, the present disclosure relates to antimicrobial compositions containing relatively high concentrations of hydrogen peroxide. In one aspect, the compositions are formulated so as to not contain any hydrogen peroxide stabilizers. Thus, the compositions can be considered to be self-stabilizing, containing relatively large amounts of hydrogen peroxide, which has a shelf life of at least one year, such as at least two years. The antimicrobial compositions contain a unique combination of hydrogen peroxide, an organic sulfonic acid or salt thereof, and a carboxylic acid such as acetic acid. In the past, the above acids have been combined with hydrogen peroxide in order to convert the hydrogen peroxide to peracetic acid. However, in the present disclosure, it was unexpectedly discovered that a relatively small amount of a carboxylic acid combined with an organic sulfonic acid or salt thereof can produce a hydrogen peroxide composition in which the hydrogen peroxide remains relatively stable. Moreover, it was discovered that the unique combination of an organic sulfonic acid or salt thereof combined with a relatively small amount of a carboxylic acid activates the efficacy of the hydrogen peroxide, making the antimicrobial composition very effective against a wide range of microorganisms.

[0023] More particularly, it was discovered that the antimicrobial compositions of the present disclosure are particularly suitable for destroying and inhibiting the growth of Clostridium difficile, even when the contact time is relatively short. For example, the antimicrobial compositions of the present disclosure are able to achieve at least a 6 log reduction against Clostridium difficile when tested after a 10 minute contact time, after a 5 minute contact time, or even after a 2 minute contact time, in accordance with ASTM Test Methods ASTM E2197-11 and E2839-11. 10 Reduction.

[0024] Because the antimicrobial compositions of the present disclosure contain relatively small amounts of carboxylic acid, and contain very small amounts of peracetic acid, the antimicrobial compositions of the present disclosure have significantly lower odor properties compared to many conventional products. For example, the antimicrobial compositions of the present disclosure can be formulated to be substantially free of peracetic acid and / or free of chlorine bleach.

[0025] The antimicrobial compositions of the present disclosure can be used in a variety of and different applications. In one embodiment, for example, the antimicrobial compositions can be used to disinfect or sanitize hard, non-porous surfaces. For example, the antimicrobial compositions are well suited for sanitizing or disinfecting floor materials, countertops, ceramic surfaces, metal surfaces, glass surfaces, stone surfaces, and the like.

[0026] The antimicrobial compositions are also well suited for sanitizing soft surfaces. Examples of soft surfaces include, but are not limited to, upholstery, fabric, upholstered recliners, sofas, chairs, seat cushions, upholstered headrests, pillows, upholstered furniture, fabric window treatments, drapes, curtains, shower curtains, fabric gym / laundry diaper bags, backpacks, fabric baskets, fabric dog / pet bedding, blankets, fabric cushion car seats, fabric stuffed animals, toys, and the like.

[0027] The antimicrobial compositions can be used to clean surfaces, sanitize surfaces, destroy microorganisms on surfaces, and / or prevent microorganisms from growing on surfaces. The antimicrobial compositions can be used in a number of different fields. For example, the antimicrobial compositions are well suited for use in the health care industry to sanitize surfaces and / or sanitize equipment. The antimicrobial compositions can be used in hospitals, for example, to prevent the spread of Clostridium difficile. The antimicrobial compositions can be used in the food service industry to sanitize and disinfect food processing equipment and other food processing surfaces, or for washing produce, such as vegetables. The antimicrobial compositions can also be marketed for consumer home use. The compositions can be used in concentrated or diluted form depending on the application.

[0028] The antimicrobial compositions generally contain a peroxide source in combination with an organic sulfonic acid or salt thereof and a carboxylic acid. The hydrogen peroxide source can comprise hydrogen peroxide. However, in other embodiments, the hydrogen peroxide source can comprise a compound that generates hydrogen peroxide. The hydrogen peroxide source can include, for example, solutions of alkali metal hydroperoxides, alkali salts of percarbonate and persulfate salts, and organic peroxides. The organic peroxides can include dicumyl peroxide, dialkyl peroxides, urea peroxide, and the like. Hydrogen peroxide itself can provide a number of advantages and benefits. Not only does hydrogen peroxide have activity against a wide range of microorganisms, but it is also relatively safe to use. Hydrogen peroxide can oxidize and / or bleach surfaces while degrading into extremely safe byproducts, namely oxygen and water.

[0029] As noted above, the antimicrobial compositions of the present disclosure contain not only relatively high concentrations of hydrogen peroxide, but also a relatively stable state of hydrogen peroxide. For example, the compositions can contain hydrogen peroxide in an amount greater than about 1 wt.%, such as an amount greater than about 2 wt.%, such as an amount greater than about 3 wt.%, such as an amount greater than about 4 wt.%, such as an amount greater than about 5 wt.%, such as an amount greater than about 6 wt.%. The hydrogen peroxide can be present in the composition in an amount less than about 10 wt.%, such as in an amount less than about 8 wt.%, such as in an amount less than about 6.5 wt.%.

[0030] According to the present disclosure, the antimicrobial composition also contains an organic sulfonic acid or a salt thereof in combination with a relatively small amount of a carboxylic acid. The organic sulfonic acid or salt thereof can be a non-surfactant sulfonic acid. Examples of sulfonic acids or salts thereof that can be used include C1-C7 alkyl sulfonic acids, sulfonated C1-C7 carboxylic acids, substituted or unsubstituted aromatic sulfonic acids, mixtures thereof, and salts thereof. In another embodiment, the alkyl sulfonic acids and sulfonated carboxylic acids have C1-C5 chains. In the case of substituted aromatic sulfonic acids, the aromatic ring can be substituted with at least one C1-C3 alkyl group. In other words, if the aromatic ring is substituted, the alkyl group can contain three (3) carbons or less. Salts of the non-surfactant organic sulfonic acids are alkali and alkaline earth metal salts, such as sodium, potassium, calcium, and magnesium salts. The salts can also include ammonium salts. Representative examples of non-surfactant organic sulfonic acids are methanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, xylenesulfonic acid, ethylbenzenesulfonic acid, and mixtures thereof.

[0031] The organic sulfonic acid or salt thereof can be present in the antimicrobial composition in an amount generally from about 0.1 wt.% to about 6 wt.%, including all increments of 0.1 wt.% therebetween. For example, the organic sulfonic acid or salt thereof can be present in the antimicrobial composition in an amount greater than about 0.5 wt.%, such as an amount greater than about 1 wt.%, such as an amount greater than about 1.5 wt.%, and generally in an amount less than about 5 wt.%, such as an amount less than about 4 wt.%, such as an amount less than about 3 wt.%. In one aspect, the organic sulfonic acid comprises methanesulfonic acid and is present in the composition in an amount from about 1.5 wt.% to about 2.5 wt.%, such as in an amount from about 1.8 wt.% to about 2.2 wt.%.

[0032] The hydrogen peroxide is combined with the organic sulfonic acid or salt thereof and a relatively small amount of a carboxylic acid. It has been found that the relatively amounts of the organic sulfonic acid and carboxylic acid in combination with the relatively large amount of hydrogen peroxide "self-stabilizes" the hydrogen peroxide, preventing degradation or conversion of the hydrogen peroxide to peracetic acid. The organic sulfonic acid and carboxylic acid are also believed to activate the efficacy of the hydrogen peroxide, making the antimicrobial composition highly effective against a variety of microorganisms, including Clostridium difficile C. difficile

[0033] In one aspect, the carboxylic acid can comprise a C1 to C 14 ​Carboxylic acid. For example, the carboxylic acid can include Ci to C4, such as Ci to C2 carboxylic acids. In one embodiment, the carboxylic acid can include formic acid, carbonic acid, and / or acetic acid. As used herein, in the context of the present application, carboxylic acid includes carbonic acid. More specifically, carbonic acid is considered to be one of the possible Ci to C2 carboxylic acids.

[0034] The carboxylic acid can be present in the ready-to-use composition in an amount greater than about 0.1 wt.%, such as an amount greater than about 0.5 wt.%, such as an amount greater than about 0.8 wt.%, such as an amount greater than about 1.2 wt.%, such as an amount greater than about 1.5 wt.%, such as an amount greater than about 1.8 wt.%. The carboxylic acid can be present in the ready-to-use antimicrobial composition in an amount less than about 6 wt.%, such as an amount less than about 5 wt.%, such as an amount less than about 4 wt.%, such as an amount less than about 3 wt.%, such as an amount less than about 2.5 wt.%, such as an amount less than about 2.2 wt.%. The carboxylic acid can be present in the ready-to-use antimicrobial composition in an amount from about 0.5 wt.% to about 6 wt.%, such as from about 1 wt.% to about 5 wt.%, such as from about 1.5 wt.% to 4 wt.%, such as from about 2 wt.% to 3 wt.%.

[0035] The weight ratio between hydrogen peroxide and the organic sulfonic acid or salt thereof, and the weight ratio between hydrogen peroxide and the carboxylic acid can vary depending on the particular application and desired results. In one aspect, the weight ratio between hydrogen peroxide and the organic sulfonic acid can be from about 40: 1 to about 1 :2, such as from about 12: 1 to about 1 : 1, such as from about 10: 1 to about 5: 1. The weight ratio between hydrogen peroxide and the carboxylic acid can be from 500: 1 to about 2: 1, such as from about 100: 1 to about 2: 1, such as from about 40: 1 to about 2: 1, such as from about 20: 1 to about 2: 1, such as from about 12: 1 to about 4: 1.

[0036] The antimicrobial composition can also contain a liquid carrier. The liquid carrier can be a solubilizing agent for one of the components in the composition. The liquid carrier can comprise water, an alcohol, or a mixture thereof. Alcohol solvents that can be used include ethanol, propanol, isopropanol, n-butanol, benzyl alcohol, ethylene glycol, propylene glycol, butylene glycol, or mixtures thereof, and the like. The amount of liquid carrier present in the composition can be adjusted to adjust the level of hydrogen peroxide in the composition. The liquid carrier can be present in an amount from about 20 wt.% to about 95 wt.%, such as from about 50 wt.% to about 80 wt.%. For example, the one or more liquid carriers can be present in the antimicrobial composition in an amount greater than about 60 wt.%, such as an amount greater than about 70 wt.%, such as an amount greater than about 75 wt.%.

[0037] The solubility and compatibility of the liquid antimicrobial composition can be further improved by the addition of an appropriate amount of other solubilizing agents, such as water solvents, surfactants, or mixtures thereof, to improve the solubility and physical properties of the solution.

[0038] Examples of hydrotropes include n-octane sulfonate, xylene sulfonate, naphthalene sulfonate, or mixtures thereof. One or more hydrotropes can be included in the antimicrobial composition typically in an amount of less than about 5% by weight, such as an amount of less than about 2% by weight, such as an amount of less than about 1% by weight. One or more hydrotropes can be present in the composition in an amount of greater than about 0.01% by weight, such as an amount of greater than about 0.1% by weight, such as an amount of greater than about 0.5% by weight.

[0039] Suitable surfactants can be selected from the group consisting of ionic, non-ionic and amphoteric surfactants, and preferably non-ionic and / or ionic surfactants or mixtures thereof. Compatible non-ionic surfactants include alkoxylated alcohols such as ethoxylated alcohols, alkoxylated glycols such as C6 to C12 alkoxylated glycols having from 2 to 50 moles of ethylene oxide or propylene oxide, alkylated glycols, or mixtures thereof. When present, the antimicrobial composition can contain one or more non-ionic surfactants in an amount of greater than about 0.1% by weight, such as an amount of greater than about 0.5% by weight, such as an amount of greater than about 1.5% by weight, such as an amount of greater than about 2.5% by weight, such as an amount of greater than about 3% by weight, such as an amount of greater than about 5% by weight, such as an amount of greater than about 7% by weight, such as an amount of greater than about 8% by weight. One or more non-ionic surfactants can be present in the composition in an amount of less than about 25% by weight, such as an amount of less than about 15% by weight, such as an amount of less than about 10% by weight, such as an amount of less than about 5% by weight. In one aspect, a relatively small amount of non-ionic surfactant can be incorporated into the composition, such as in an amount of less than about 2.5% by weight, such as in an amount of less than about 1.5% by weight, such as in an amount of less than about 1% by weight. 18 alkoxylated glycols such as C6 to C12 alkoxylated glycols having from 2 to 50 moles of ethylene oxide or propylene oxide, alkylated glycols, or mixtures thereof. When present, the antimicrobial composition can contain one or more non-ionic surfactants in an amount of greater than about 0.1% by weight, such as an amount of greater than about 0.5% by weight, such as an amount of greater than about 1.5% by weight, such as an amount of greater than about 2.5% by weight, such as an amount of greater than about 3% by weight, such as an amount of greater than about 5% by weight, such as an amount of greater than about 7% by weight, such as an amount of greater than about 8% by weight. One or more non-ionic surfactants can be present in the composition in an amount of less than about 25% by weight, such as an amount of less than about 15% by weight, such as an amount of less than about 10% by weight, such as an amount of less than about 5% by weight. In one aspect, a relatively small amount of non-ionic surfactant can be incorporated into the composition, such as in an amount of less than about 2.5% by weight, such as in an amount of less than about 1.5% by weight, such as in an amount of less than about 1% by weight.

[0040] Instead of or in addition to one or more non-ionic surfactants, the antimicrobial composition can also contain one or more anionic surfactants. Suitable anionic surfactants include alkyl sulfates, alkyl ether sulfates, alkyl ether sulfonic acids and salts thereof, alkyl benzene sulfates, alkanol amide sulfates, ethoxylated alkyl phenols, or mixtures thereof. Other surfactants that can be used include quaternary ammonium salts or tertiary amine N-oxides. In one embodiment, the antimicrobial composition contains a salt of alkyl benzene sulfonate, such as sodium dodecyl benzene sulfonate.

[0041] The one or more anionic surfactants are typically included in the antimicrobial composition in relatively small amounts. For example, the one or more anionic surfactants can be present in the composition in an amount of less than about 5 wt.%, such as less than about 3 wt.%, such as less than about 1.5 wt.%, such as less than about 1 wt.%, such as less than about 0.8 wt.%. The one or more anionic surfactants can be present in the composition in an amount of greater than about 0.001 wt.%, such as greater than about 0.01 wt.%, such as greater than about 0.1 wt.%, such as greater than about 0.3 wt.%.

[0042] In the past, antimicrobial compositions containing hydrogen peroxide have typically required the use of a stabilizer for the hydrogen peroxide. However, it has been unexpectedly discovered that the compositions of the present disclosure self-stabilize the hydrogen peroxide without the need to add any hydrogen peroxide stabilizer. Thus, in one embodiment, the antimicrobial composition is free of hydrogen peroxide stabilizers. For example, the antimicrobial composition can be free of one or more hydrogen peroxide stabilizers including phosphorus compounds, polycarboxylic acids, and phosphonates. For example, the composition can be free of phosphoric acid or derivatives including phosphonates. The composition can also be formulated to be free of metal chelators. More specifically, the antimicrobial composition can be formulated so as to be free of one or more of the following hydrogen peroxide stabilizers: phosphoric acid, 1-hydroxyethylidene diphosphonic acid (HEDP), phytic acid, amino phosphates, phosphonates and glutamic acid sodium, ethylenediamine-N,N'-disuccinic acid, NaH2P04, sodium tripolyphosphate, organic phosphonic acids, aminophosphonates, silver dihydrogen citrate, diphosphonic acid, ethylenediaminetetraacetic acid (EDTA), N-(hydroxyethyl)-ethylenediaminetriacetic acid (HEDTA), ethylenediamine-N,N'-disuccinic acid, pyridine carboxylic based stabilizers such as picolinic acid or dipicolinic acid, tris(methylene phosphonic acid), diethylenetriamine-penta(methylene phosphonic acid), 2-hydroxyethyliminobis(ethylene phosphonic acid), citric acid, nitrio triacetic acid (NTA), 2-hydroxyethyliminodiacetic acid (HEIDA), salts thereof, cyclohexane-1,2-diaminotetramethylenephosphonic acid or water-sol, diethylenetriaminepenta(methylene phosphonic acid), colloidal stannate, diethylenetriaminepentaacetic acid (DTPA), citrate, gallic acid, malate, malonate, oxalacetate, oxalate, pyruvate, succinate, or mixtures thereof.

[0043] As noted above, the antimicrobial compositions of the present disclosure are also formulated to promote stability of the hydrogen peroxide and inhibit conversion of the hydrogen peroxide to peracetic acid. In addition, the antimicrobial compositions are formulated such that substantially no peracetic acid is added to the composition as a component. In one aspect, the antimicrobial compositions contain peracetic acid in an amount less than about 1 wt%, such as less than about 0.75 wt%, such as less than about 0.50 wt%, such as less than about 0.25 wt%. In one particular embodiment, the compositions are substantially free of peracetic acid.

[0044] Other additives can also be added to the antimicrobial compositions of the present disclosure to provide compositions having properties suitable for end use applications. Typical examples include corrosion inhibitors, pH adjusting agents, emulsifiers, fragrances, dyes, preservatives, antifoams, and mixtures thereof.

[0045] In one embodiment, for example, the antimicrobial compositions can contain a corrosion inhibitor. Corrosion inhibitors that can be used include borates, phosphates, polyphosphates, sodium benzoate, sodium gluconate, sodium silicate, sodium molybdate, sodium bisulfate, benzotriazole, or mixtures thereof. When present, the corrosion inhibitor can be contained in the composition in an amount of about 0.001 wt% to about 2 wt%, such as about 0.01 wt% to about 1 wt%.

[0046] The antimicrobial compositions can also contain one or more pH adjusting agents. For many applications, the compositions have a pH of less than about 7, such as less than about 5, such as less than about 4, such as less than about 3, such as less than about 2, such as less than about 1. In one aspect, the pH adjusting agent can include a base to increase the pH. For example, the base can include a hydroxide, such as sodium hydroxide, potassium hydroxide, ammonium hydroxide, calcium hydroxide, magnesium hydroxide, or mixtures thereof. The pH adjusting agent can generally be present in the antimicrobial composition in an amount of about 0.01 wt% to about 4 wt%. For example, the pH adjusting agent can be present in the composition in an amount greater than about 0.1 wt%, such as greater than about 0.3 wt%, and less than about 1.5 wt%, such as less than about 1.3 wt%.

[0047] In one embodiment, relatively concentrated antimicrobial compositions are produced and sold or otherwise distributed to end users. The end user can then dilute the concentrated solution during use or prior to use. It is particularly advantageous that the antimicrobial compositions can be diluted with water, such as tap water.

[0048] In one embodiment, a relatively concentrated antimicrobial composition is prepared that contains hydrogen peroxide in an amount of about 20% to about 70% by weight, such as about 22% to about 65% by weight, one or more organic sulfonic acids or salts thereof in an amount of about 5% to about 35% by weight, such as about 15% to about 25% by weight, and one or more carboxylic acids in an amount of about 5% to about 35% by weight. Other ingredients that can reduce the water content can be present.

[0049] In another embodiment, the concentrated composition contains only inert components and / or all components other than hydrogen peroxide. Hydrogen peroxide can be added to the concentrate at the time of use. For example, the concentrated composition can contain one or more organic sulfonic acids in an amount of about 5% to about 35% by weight, such as about 15% to about 25% by weight, and one or more carboxylic acids in an amount of about 5% to about 35% by weight. Then, an aqueous hydrogen peroxide solution can be added to the concentrated composition at the time of use in a manner that produces the desired concentrations of the components. The aqueous hydrogen peroxide solution can contain hydrogen peroxide in an amount of about 5% to about 80% by weight, including all 0.5% increments therebetween. In one aspect, the aqueous hydrogen peroxide solution can contain hydrogen peroxide in an amount of less than about 24.5% by weight, such as about 18% to about 24% by weight.

[0050] The antimicrobial composition can be used in any suitable application where disinfection, sterilization, cleaning, and / or bleaching is desired. The antimicrobial composition can be used for consumer household use, for use in the health care field, for use in the food processing field or food service field, for sterilization of surfaces in dairy and brewery plants, for use in the veterinary field, and / or for cleaning rooms.

[0051] The antimicrobial composition can be applied to the opposing surface using a variety of methods and techniques. For example, the antimicrobial composition can be sprayed onto the opposing surface, or the object can be immersed in the composition.

[0052] One particularly useful application method is to impregnate the antimicrobial composition into a wiping substrate. The wipe can be a disposable wipe that is impregnated with the antimicrobial composition and stored in a container that dispenses the wipe to a user. The container with the wipe can contain a single wipe or several wipes. Suitable containers include a pouch containing a single wipe, such as a moist towelette that is torn open by the user, or can be a pouch or other container with a resealable opening containing several wipes in a stack, roll, or other suitable form that allows a single wipe to be removed from the opening at a time. Typically the pouch is prepared from a fluid impermeable material, such as a film, coated paper, or foil, or other similar fluid impermeable material. Another way to dispense the wipes of the present disclosure is to place the wipes in a fluid impermeable container with an opening to access the wipes in the container. The container can be a molded plastic container with a fluid impermeable lid. Typically the lid will have an opening to access the wipes in the container. The wipes in the container can be in an interleaved stack so that when a wipe is removed from the container the next wipe is positioned at the opening of the container ready for the user to remove the next wipe. Alternatively, the wipes can be a continuous material that is perforated between individual wipes of the continuous material. The continuous wipe material with perforations can be in a folded form or can be in a roll form. Typically in a roll form, wipe material is provided from the center of the roll material. As with an interleaved stack, when a wipe is removed from the container the next wipe is positioned at the opening to facilitate removal of the next wipe when needed.

[0053] The antimicrobial composition can be impregnated into the wipe so that the wipe is premoistened and will squeeze or release the antimicrobial composition onto a surface as the wipe is passed over the surface to be treated. Typically, the antimicrobial composition is saturated in the wipe so that the wipe will release the antimicrobial composition onto a surface with a wiping action. Typically, the antimicrobial composition is present in an amount of about 2 parts by weight to 6 parts by weight per 1 part by weight of the wipe substrate, more preferably about 3 parts by weight to about 5 parts by weight per 1 part by weight of the wipe substrate. Within these ranges, complete saturation of the substrate can be achieved. It should be noted that the amount of antimicrobial composition can be increased or decreased to achieve complete saturation of the wipe substrate depending on the particular wipe substrate.

[0054] Suitable wipe substrates include woven and nonwoven materials. Essentially any nonwoven web material can be used. Exemplary nonwoven materials can include, but are not limited to, meltblown, coform, spunbond, airlaid, hydroentangled nonwoven, spunlace, bonded carded web, and laminates thereof. Optionally, the nonwoven can also be laminated with a film material. The fibers used to make the wipe substrate can be cellulosic fibers, thermoplastic fibers, and mixtures thereof. The fibers can also be continuous fibers, discontinuous fibers, staple fibers, and mixtures thereof. The basis weight of the nonwoven web can vary from about 12 grams per square meter to 200 grams per square meter or more.

[0055] Once applied to a surface, the antimicrobial composition is allowed to remain on the surface for a period of time. As mentioned, it has been unexpectedly discovered that the antimicrobial composition has significantly reduced the contact time required to kill target microorganisms.

[0056] The present disclosure can be better understood with reference to the following examples.

[0057] Examples

[0058] Example Number 1

[0059] The following examples demonstrate some of the advantages and benefits of the present disclosure.

[0060] Various different antimicrobial formulations were prepared and tested against C. difficile. The following test procedure was used:

[0061] ASTM Standard E2197-11. Standard quantitative carrier test-2 method for determining bactericidal, virucidal, fungicidal, mycobactericidal, and sporicidal activities of chemical germicides.

[0062] Table 1 below lists the formulations prepared and tested. The ingredients were mixed at room temperature. The order of addition is not critical to the preparation of the antimicrobial compositions of the present disclosure. It was noted that formulations containing lower amounts of acetic acid, particularly 2% acetic acid, had significantly lower odor compared to known commercial products containing higher levels of acetic acid and peracetic acid.

[0063] Table 1

[0064]

[0065] The above liquid formulations were evaluated for efficacy against C. difficile spores using the ASTM quantitative carrier test method (ASTM E2197-11) at 2 minute, 3 minute, 4 minute, and 5 minute contact times. The following results were obtained. C. difficile ​

[0066] Table 2

[0067]

[0068] Acceptance criteria: ≥6.0 log 10 Decreased

[0069] As shown above, the antimicrobial compositions of the present disclosure show excellent antimicrobial efficacy even after short contact times.

[0070] The stability of the samples in Table 1 was also tested. In particular, the formulations were stored in an oven at a temperature of 54 °C. The percentage of active hydrogen peroxide in the formulation was measured at the time of preparation of the formulation and then weekly during the stability storage. The percentage of hydrogen peroxide loss was calculated by the following formula:

[0071] [Initial H202% - H202% after storage in oven] / Initial H202% x 100

[0072] The stability test results are shown in Table 3 below.

[0073] Table 3

[0074]

[0075] At about 5.0-5.2% H 2 O 2 Formulations were prepared under

[0076] As shown above, all formulations showed less than 5% hydrogen peroxide loss after two weeks at 54 °C, which is equivalent to a shelf life of one year at room temperature. The stability results are unexpected and surprising, particularly given the fact that there is no hydrogen peroxide stabilizer present in the formulation. Reducing the amount of carboxylic acid in the formulation results in a more stable product.

[0077] As shown above, the antimicrobial compositions of the present disclosure can show less than about 2%, such as less than about 1% hydrogen peroxide loss after one or two weeks of storage at 54 °C.

[0078] Wipe substrates were saturated with Sample Nos. 6 and 7 and also tested for stability. The wipe substrates were made of 100% polypropylene fibers. The wipe substrates were ERHT bonded and were not pre-treated with any surfactants. The loading ratio of liquid to wipe substrate was 4: 1 by weight. The wipes were stored in an oven at 54 °C for four weeks. The initial hydrogen peroxide concentration was determined and then measured weekly during the stability study. The results are shown in Tables 4 and 5. Table 4 shows the results using Sample No. 6, while Table 5 shows the results using Sample No. 7.

[0079] Table 4. Stability test results for Sample No. 6 wipe

[0080]

[0081] Table 5. Stability test results for Sample No. 7 wipe

[0082]

[0083] As shown above, the hydrogen peroxide concentration decreased by no more than 5% even after four weeks. The hydrogen peroxide concentration decreased by no more than 2%, such as no more than about 1.5%, after three weeks. These results are surprising and compelling because the composition does not contain a hydrogen peroxide stabilizer.

[0084] Example No. 2

[0085] The following examples demonstrate additional advantages and benefits of the present disclosure.

[0086] Various different antimicrobial formulations were prepared and tested as follows.

[0087] Table 6

[0088]

[0089] The stability of the above samples was tested as described in Example 1. The results are in Table 7 below. As shown in Table 7, it was noted that the organic sulfonic acids, i.e., BSA (Sample No. 10), TSA (Sample No. 11), and dodecylbenzenesulfonic acid sodium salt (Sample No. 12), showed similar stability profiles in formulations containing high levels of hydrogen peroxide.

[0090] Table 7

[0091]

[0092] The antimicrobial compositions of Sample No. 10 and Sample No. 11 showed the lowest percentage loss of hydrogen peroxide. For example, Sample No. 10 lost about 4.69% hydrogen peroxide and Sample No. 11 lost about 4.38% hydrogen peroxide. However, it is noted that Sample No. 9, which did not contain any organic sulfonic acid or salt thereof, exhibited a higher percentage loss of hydrogen peroxide than the above-mentioned Sample Nos. 10 and 11, which respectively included BSA and TSA.

[0093] Surprisingly, it was found that less hydrogen peroxide was lost when the composition contained at least one organic sulfonic acid or salt thereof (even in small amounts) as compared to similar or otherwise nearly identical compositions that did not contain any organic sulfonic acid or salt thereof. These results are surprising and compelling because the compositions did not contain a hydrogen peroxide stabilizer.

[0094] Example No. 3

[0095] Various different antimicrobial formulations containing different carboxylic acids and salts thereof were prepared and tested as follows.

[0096] Table 8

[0097]

[0098] The above samples were evaluated for efficacy against C. difficile spores after a 3 minute contact time as described in Example No. 1. As shown in Table 9 below, it was found that the antimicrobial compositions showed good efficacy when the carboxylic acid used in the composition had a carbon chain length of C1 to C5 (e.g., formic acid, acetic acid, citric acid). C. difficile Table 9

[0099]

[0100]

[0101] 6.0 log 10 Decrease Acceptance criteria: ≥ Samples Nos. 13-15, which respectively included formic acid, acetic acid and glycolic acid, were effective against C. difficile when about 8% w / w hydrogen peroxide and about 1-4% w / w MSA were present in the composition. Surprisingly, these example compositions showed a 6 log 10 or greater decrease after a 3 minute or less contact time when tested against C. difficile according to ASTM Test Method E2197-11.

[0102]

[0103] ​These and other modifications and variations to the illustrative embodiments can be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present application, which is more particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments can be interchanged both physically and functionally. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the application as described and further described in that further patent claims.

Claims

1. An antimicrobial composition comprising an aqueous solution, said aqueous solution comprising: Hydrogen peroxide is present in the composition in an amount of at least about 1% by weight; Organic sulfonic acids or their salts; C1 to C 14 A carboxylic acid, present in the composition in an amount greater than about 0.1% by weight; and The composition has a pH less than 4, and when tested against Clostridium difficile according to ASTM test method E2197-11, the composition shows 6 log [value missing] after a contact time of 10 minutes or less. 10 Or a greater reduction.

2. The antimicrobial composition as defined in claim 1, wherein the organic sulfonic acid or its salt comprises C1-C5 alkyl sulfonic acid, sulfonated C1-C5 carboxylic acid, substituted or unsubstituted aromatic sulfonic acid, monoalkylbenzene sulfonic acid, dialkylbenzene sulfonic acid, or its salt, or mixture thereof, wherein the substituted aromatic sulfonic acid is substituted with at least one C1-C3 alkyl group.

3. The antimicrobial composition as defined in any of the preceding claims, wherein the organic sulfonic acid or its salt comprises methanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, or its salt or mixture thereof.

4. The antimicrobial composition as defined in any of the preceding claims, wherein the organic sulfonic acid or its salt is present in the composition in an amount of about 0.1% by weight to about 6% by weight, such as about 0.2% by weight to about 4% by weight.

5. The antimicrobial composition as defined in any of the preceding claims, wherein the hydrogen peroxide is present in the composition in a weight ratio of about 40:1 to about 1:2, such as about 12:1 to about 5:1, relative to the organic sulfonic acid or its salt.

6. The antimicrobial composition as defined in any of the preceding claims, wherein the hydrogen peroxide is present in the composition in an amount of about 1% to about 8% by weight, such as in an amount of about 3% to about 6.5% by weight.

7. An antimicrobial composition as defined in any of the preceding claims, wherein the composition is free of pyridine carboxylic acid-based stabilizers, such as pyridinecarboxylic acid and / or pyridinedicarboxylic acid.

8. The antimicrobial composition as defined in any of the preceding claims, wherein the composition is free of 1-hydroxyethylidene-1,1-diphosphonic acid.

9. The antimicrobial composition as defined in any of the preceding claims, wherein when tested against Clostridium difficile according to ASTM test method E2197-11, the composition exhibits 6 log [value missing] after a 5-minute contact time. 10 Or a greater reduction.

10. The antimicrobial composition as defined in any of the preceding claims, wherein the C1-C4 carboxylic acid comprises acetic acid.

11. The antimicrobial composition as defined in any of the preceding claims, wherein the C1-C 14 The carboxylic acid is present in the composition in an amount of about 0.5% by weight to about 6% by weight.

12. The antimicrobial composition as defined in any of the preceding claims, wherein the composition further comprises a nonionic surfactant.

13. The antimicrobial composition as defined in any of the preceding claims, wherein the composition further comprises an anionic surfactant.

14. The antimicrobial composition as defined in claim 13, wherein the anionic surfactant comprises linear alkylbenzene sulfonic acid or a salt thereof, alkyl sulfate, alkanolamide sulfate, ethoxylated alkylphenol, or a mixture thereof.

15. The antimicrobial composition as defined in claim 13, wherein the anionic surfactant comprises sodium dodecylbenzenesulfonate.

16. The antimicrobial composition as defined in any of the preceding claims, wherein the composition further comprises a pH adjuster.

17. The antimicrobial composition as defined in claim 16, wherein the pH adjuster comprises sodium hydroxide.

18. The antimicrobial composition as defined in any of the preceding claims, wherein after storage at 54°C for one week, the composition exhibits a loss of less than about 2% of hydrogen peroxide.

19. An antimicrobial composition as defined in any of the preceding claims, wherein after storage at 54°C for two weeks, the composition exhibits a loss of less than about 5% by weight, such as less than about 1% by weight of hydrogen peroxide.

20. A pre-wetted wiping material, comprising: Absorbent substrate; and An antimicrobial composition as defined in any of the preceding claims, impregnated into the absorbent substrate.

21. The pre-wetted wipe as defined in claim 20, wherein the antimicrobial composition is impregnated into the absorbent substrate in an amount of about 2 to 6 parts by weight of the antimicrobial composition per 1 part by weight of the absorbent substrate.

Images