Solid cleaning composition

Abstract

The present invention relates to a solid cleaning composition. In particular, the present invention relates to a cleaning composition that provides excellent antimicrobial, e.g., antibacterial, efficacy with a consumer-friendly contact time of 10-30 seconds. The solid composition comprises a selected ammonium salt and one or more carboxylic acids having a pKa in the range of 2.5-4.5, and the pH of a 5% solution of the composition is in the range of 2.5-6.5.

Description

[Technical field]

[0001] The present invention relates to cleaning compositions, particularly solid cleaning compositions that provide superior antimicrobial, e.g., antibacterial, efficacy. [Background technology]

[0002] WO 2018 121946 (Unilever) discloses a skin pH antimicrobial composition comprising (a) 5-40% by weight of an ammonium salt having at least one covalently bonded hydrogen attached to a nitrogen or an anionic surfactant having an ammonium group as a counterion or mixtures thereof and (b) 0.1-20% by weight of a carboxylic acid having a pKa value greater than 4.5.

[0003] However, the carboxylic acids considered in the prior art are those with a pKa greater than 4.5. Although they provide good antimicrobial efficacy in the presence of the considered anionic surfactant system, these acids are medium chain fatty acids that are expensive and associated with less than desirable odors. Such odors therefore require addressing the fragrance system, which further increases costs.

[0004] Therefore, there is a need to provide a cleaning composition that overcomes one or more of the shortcomings of the prior art.

[0005] It has now been found that carboxylic acids having a pKa in the range of 2.5 to 4.5, such as benzoic acid, which are more easily incorporated into cleaning compositions without odor problems, when combined with an ammonium salt, such as ammonium chloride, provide a synergistic antimicrobial effect. Moreover, the antimicrobial effect is achieved in a short time, such as 10 to 30 seconds, for example 20 seconds. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2018 121946 Summary of the Invention

[0007] In a first aspect, the present invention provides a method for producing a composition comprising: a. 2 to 15 wt. % of an ammonium salt selected from ammonium chloride, ammonium benzoate, ammonium citrate, ammonium carbonate, ammonium acetate, ammonium sulfate, isopropylammonium chloride, and mixtures thereof; and b. 2-25 wt% of a carboxylic acid having a pKa in the range of 2.5-4.5 1. A solid cleaning composition comprising: The present invention relates to a solid cleaning composition, wherein the pH of a 5% solution of the composition is in the range of 2.5 to 6.5.

[0008] In a second aspect, the present invention provides a method for providing an antimicrobial effect, comprising the steps of: a. applying a composition of the first aspect to a surface; and b. Optionally, rinsing the surface to which the composition is applied. The present invention relates to a method comprising the steps of:

[0009] In a third aspect, the present invention relates to the use of a composition of the first aspect in providing an antimicrobial effect.

[0010] In a fourth aspect, the present invention relates to the use of an ammonium salt as an enhancer of the antimicrobial efficacy of a solid cleaning composition comprising a carboxylic acid having a pKa in the range of 2.5 to 4.5, wherein the pH of a 5% solution of the composition is in the range of 2.5 to 6.5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Any feature of one aspect of the invention can be utilized in any other aspect of the invention. The word "comprising" is intended to mean "including" but not necessarily "consisting of" or "composed of". In other words, the listed steps or options need not be exhaustive. Except for the operating and comparative examples, or where otherwise expressly indicated, all numbers in this description expressing amounts of materials or reaction conditions, physical properties of materials, and / or uses should be understood to be modified by the word "about". Numerical ranges expressed in the format "x to y" are understood to include x and y. When multiple preferred ranges are described in a particular feature in the format "x to y", all ranges combining the different endpoints are also contemplated. Unless otherwise specified, amounts used herein are expressed in weight percent based on the total weight of the composition and are abbreviated as "wt%". The use of any and all examples and exemplary language, such as "such as," provided herein is intended merely to make the invention more clear and does not otherwise limit the scope of the invention as claimed in any way.

[0012] For the purposes of the present invention, the terms "antimicrobial benefit" or "antimicrobial effect" or "antimicrobial efficacy" may be used interchangeably and represent the same meaning. Preferably, "antimicrobial benefit" or "antimicrobial effect" or "antimicrobial efficacy" refers to the reduction in the number of microorganisms, e.g., bacteria, fungi, viruses. Such antimicrobial effect is preferably obtained when the composition of the present invention is applied to a surface, which may be an inanimate or animate surface. More preferably, the composition is applied to a biological substrate, e.g., human skin. "Skin" as used herein is preferably meant to include the skin of any part of the body, e.g., the face, neck, chest, back, arms, armpits, hands, feet, buttocks and scalp.

[0013] In a first aspect, the present invention provides a method for producing a composition comprising: a. 2 to 15 wt. % of an ammonium salt selected from ammonium chloride, ammonium benzoate, ammonium citrate, ammonium carbonate, ammonium acetate, ammonium sulfate, isopropylammonium chloride, and mixtures thereof; and b. 2-25 wt% of a carboxylic acid having a pKa in the range of 2.5-4.5 1. A solid cleaning composition comprising: The present invention relates to a solid cleaning composition, wherein the pH of a 5% solution of the composition is in the range of 2.5 to 6.5.

[0014] The composition according to the present invention is a solid cleaning composition. Preferably, the composition is in the form of a bar. Alternatively, the composition can be in the form of a powder or in the form of a concentrated powder.

[0015] Ammonium salts Generally, salts are added to cleaning compositions as electrolytes to provide the correct ionic strength.

[0016] The composition comprises an ammonium salt selected from ammonium chloride, ammonium benzoate, ammonium citrate, ammonium carbonate, ammonium acetate, ammonium sulfate, isopropylammonium chloride, or mixtures thereof.

[0017] Preferably, the ammonium salt is selected from ammonium chloride, ammonium citrate, and mixtures thereof.

[0018] The composition comprises 2 to 15 wt %, preferably 3 to 13 wt %, more preferably 4 to 12 wt %, even more preferably 5 to 11 wt %, even more preferably 6 to 10 wt %, even more preferably 7 to 9 wt %, and even more preferably 8 to 9 wt % of the ammonium salt described above.

[0019] Carboxylic Acid The composition comprises one or more carboxylic acids having a pKa in the range of 2.5 to 4.5. Preferably, the composition comprises one or more carboxylic acids having a pKa in the range of 2.5 to less than 4.5. More preferably, the composition comprises one or more carboxylic acids having a pKa in the range of 2.5 to 4.4.

[0020] Preferably, the one or more carboxylic acids are selected from aromatic carboxylic acids, cyclic carboxylic acids, aliphatic carboxylic acids, and mixtures thereof.

[0021] Examples of aromatic carboxylic acids include benzoic acid (pKa=4.2), 2-hydroxybenzoic acid (also known as salicylic acid; pKa=2.97), 3-hydroxybenzoic acid (also known as m-salicylic acid; pKa=3.82), 4-hydroxybenzoic acid (pKa=4.5).

[0022] Examples of aliphatic carboxylic acids that may be present in the composition include citric acid (pKa=3.13), lactic acid (pKa=3.86), L(+) tartaric acid (pKa=2.89), mesotartaric acid (pKa=3.22), glycolic acid (pKa=3.6), and mixtures thereof.

[0023] More preferably, the one or more carboxylic acids are selected from aromatic carboxylic acids, aliphatic carboxylic acids and mixtures thereof. Even more preferably, the one or more carboxylic acids are selected from aromatic carboxylic acids. Even more preferably, the carboxylic acid is selected as benzoic acid.

[0024] The composition comprises 2 to 25 wt%, preferably 3 to 22 wt%, more preferably 5 to 20 wt%, even more preferably 7 to 17 wt%, even more preferably 9 to 15 wt%, even more preferably 10 to 14 wt%, and even more preferably 12 to 13 wt% of one or more carboxylic acids having a pKa in the range of 2.5 to 4.5 described above.

[0025] The above-described ammonium salts in combination with the above-described carboxylic acids have been found to provide a synergistic antimicrobial effect.

[0026] Anionic surfactants: Preferably, the composition further comprises an anionic surfactant. Preferably, the anionic surfactant is selected from alkyl sulfates, alkyl sulfosuccinates, alkyl sulfoacetates, alkyl ether sulfates, isethionates, taurates and mixtures thereof.

[0027] Examples of alkyl sulfates which may be used as anionic surfactants in the present compositions include sodium lauryl sulfate (SLS), sodium myristyl sulfate, and mixtures thereof.

[0028] Examples of alkyl sulfosuccinates that can be used as anionic surfactants include disodium lauryl sulfosuccinate.

[0029] An example of an alkyl sulfoacetate includes sodium sulfoacetate. An example of an isethionate includes sodium isethionate. An example of a taurate includes sodium taurate.

[0030] Preferably, the composition comprises 10 to 80 wt %, more preferably 15 to 70 wt %, even more preferably 20 to 60 wt %, even more preferably 25 to 50 wt %, and even more preferably 30 to 40 wt % of anionic surfactant.

[0031] Amphoteric surfactants Amphoteric surfactants provide improved foam when added to the present compositions.

[0032] Preferably, the composition further comprises an amphoteric surfactant. Preferably, the amphoteric surfactant is selected from cocamidopropyl betaine (CAPB), cocamide monoethanolamide (CMEA), cocoamphoacetate, and mixtures thereof.

[0033] Preferably, the composition comprises 0.1 to 10 wt %, more preferably 0.5 to 8 wt %, even more preferably 1 to 7 wt %, even more preferably 2 to 5 wt %, and even more preferably 3 to 5 wt % of an amphoteric surfactant.

[0034] essential oil Preferably, the composition further comprises one or more essential oils. These essential oils may be selected from thymol, terpineol, carvacrol, eugenol, menthol and mixtures thereof. More preferably, the essential oils may be selected from thymol, terpineol, carvacrol, eugenol and mixtures thereof. Even more preferably, the essential oils may be selected from thymol, terpineol, eugenol and mixtures thereof. Even more preferably, the essential oils may be selected from thymol, terpineol, eugenol and mixtures thereof. In such a case, it is preferred that the w / w ratio of the amount of thymol to the amount of terpineol is between 1:0.1 and 1:10. More preferably, the ratio is between 1:0.5 and 1:2.

[0035] Preferably, the composition comprises 0.0001-5 wt%, more preferably 0.001-2 wt%, even more preferably 0.01-1 wt%, even more preferably 0.05-0.1 wt% of one or more essential oils.

[0036] pH of the composition The pH of a 5% solution of the composition is in the range of 2.5 to 6.5, preferably 3.0 to 6, more preferably 3.5 to 5.5, and even more preferably 4.0 to 4.5. Preferably, the 5% solution of the composition is prepared using demineralized water.

[0037] Structurant Preferably, the composition comprises a structuring agent, preferably selected from silica, talc, calcite, pumice, tricalcium phosphate, chalk, fuller's earth, kaolin, starch, gum, silica, sodium polyacrylate, tetraalkyl and / or trialkylaryl ammonium smectites, chemically modified magnesium aluminum silicate, organically modified montmorillonite clay, hydrous aluminum silicate, fumed silica, carboxyvinyl polymers, sodium carboxymethylcellulose, ethylene glycol monostearate, and fatty acids having carbon chains from C10 to C20, such as lauric acid, myristic acid, palmitic acid, stearic acid and oleic acid, and mixtures thereof.

[0038] Talc is a magnesium silicate mineral material with a layered silicate structure and Mg3Si4(OH) 22 and may be available in a hydrated form. It has a plate-like morphology and is lipophilic / hydrophobic in nature, i.e., it is wetted by oil but not by water.

[0039] Calcium carbonate or chalk exists in three crystalline forms: calcite, aragonite and vaterite. The natural forms of calcite are rhombohedral or cubic, aragonite is acicular or dendritic, and vaterite is spheroidal. Commercially, calcium carbonate or chalk, known as precipitated calcium carbonate, is produced by the carbonation process, in which carbon dioxide gas is bubbled into an aqueous suspension of calcium hydroxide. In this process, the crystalline form of calcium carbonate is calcite or a mixture of calcite and aragonite.

[0040] The starch may be used directly or may be modified during the preparation of the bar composition so that the starch becomes partially or fully gelatinized.

[0041] Another suitable starch is pregelatinized starch, which is a starch that has been gelatinized before being added as an ingredient to the bar composition of the present invention.Various forms that gel at different temperatures are available, such as cold water dispersible starch.An example of a commercially available pregelatinized starch is FARMAL® CS 3400.

[0042] Preferably, the composition comprises the structuring agent in an amount in the range of from 1 to 50 wt%, more preferably from 3 to 45 wt%, even more preferably from 5 to 30 wt%, and even more preferably from 10 to 25 wt%.

[0043] polymer Preferably, the composition further comprises a water soluble polymer, preferably such polymer is selected from polyvinyl alcohol, polyvinylpyrrolidone, sodium carboxymethylcellulose, polyethylene glycol, methylcellulose, hydroxypropylmethylcellulose and mixtures thereof.

[0044] Preferably, the composition comprises 1-20 wt% of the water-soluble polymer, more preferably 3-17 wt%, even more preferably 5-15 wt%, even more preferably 7-13 wt%, and even more preferably 9-12 wt%.

[0045] Such polymers may be added to the composition mix or may be used to coat the composition, for example, if the composition is in the form of a bar or tablet, such polymers may form the outer water-soluble coating of such bar or tablet.

[0046] Format of the composition: The composition is in solid form.Preferably, the composition is formulated in the form of a bar.In such a case, the bar can be manufactured using known methods such as grinding and extrusion route.Alternatively, the composition can be formulated in the form of a powder or concentrated powder.In such a case, spray drying technology can be used to manufacture such powder.

[0047] When the composition is formulated in the form of a bar, it preferably comprises a polyhydric alcohol (also called polyol) or a mixture of polyols. Polyol is a term used herein to denote a compound having multiple hydroxyl groups (at least two, preferably at least three) and being highly water soluble, preferably freely soluble in water. Many types of polyols are available, including relatively low molecular weight short chain polyhydroxy compounds such as glycerol and propylene glycol; sugars such as sorbitol, mannitol, sucrose and glucose; modified carbohydrates such as hydrolyzed starch, dextrins and maltodextrins; and polymeric synthetic polyols such as polyalkylene glycols, e.g. polyoxyethylene glycol (PEG) and polyoxypropylene glycol (PPG). Particularly preferred polyols are glycerol, sorbitol and mixtures thereof. The most preferred polyol is glycerol. The bar according to the invention preferably comprises 0-8 wt %, more preferably 1-7.5 wt % of polyol.

[0048] Preferably, the composition further comprises an opacifying agent. When an opacifying agent is present, the bar is generally opaque. Examples of opacifying agents include titanium dioxide, zinc oxide, etc. An alternative opacifying agent is zinc stearate. The bar may take the form of a water-clear, i.e. transparent, bar, in which case it does not contain an opacifying agent.

[0049] Preferred bars may additionally contain up to 30 wt% of benefit agents. Preferred benefit agents include moisturizers, emollients, sunscreens and anti-aging compounds. These agents may be added at any appropriate stage in the bar preparation process.

[0050] When the composition is formulated in the form of a bar, it preferably contains water in an amount of 10-20 wt%, more preferably 14-18 wt%.

[0051] Alternatively, the composition may be formulated in powder form or concentrated powder form. In such a case, the composition is in dry form and preferably contains 1-5 wt%, more preferably 1-3 wt%, even more preferably 1-2 wt% water. Such dry concentrated powders are rehydratable powders which may be free-flowing or in the form of tablets, e.g. packed in suitable pouches or sachets. When formulated in the form of tablets, they may be optionally coated with water-soluble polymers, e.g. polyvinyl alcohol, polyvinylpyrrolidone, sodium carboxycellulose, polyethylene glycol, methylcellulose, hydroxypropylmethylcellulose. Such rehydratable powders are preferably rehydrated by the end user to prepare liquid cleaning compositions, e.g. handwash and bodywash, with an appropriate amount of concentrated powder, e.g. 5 grams, to an appropriate amount of water, e.g. 100 mL. A suitable container, preferably equipped with a pump, may be supplied with such powder or concentrated powder that can be used to prepare such liquid compositions.

[0052] The composition may further comprise one or more of the following ingredients:

[0053] The composition preferably further comprises a skin lightening agent selected from aloe extract, ammonium lactate, arbutin, azelaic acid, kojic acid, butylated hydroxyanisole, butylated hydroxytoluene, citric acid esters, 3-diphenylpropane derivatives, ellagic acid, fennel extract, glucopyranosyl-1-ascorbate, gluconic acid, glycolic acid, hydroquinone, 4-hydroxyanisole, linoleic acid, magnesium ascorbyl phosphate, 2,4-resorcinol derivatives, 3,5-resorcinol derivatives, vitamins such as vitamin B6, vitamin B12, vitamin C, vitamin A, resorcinol derivatives and mixtures thereof.

[0054] The composition may preferably further comprise a preservative to protect the composition from the growth of potentially harmful microorganisms. Particular preferred preservatives include hydantoin derivatives, propionate salts, various quaternary ammonium compounds, phenoxyethanol, imidazolidinyl urea, sodium dehydroacetate, and benzyl alcohol. Preservatives are preferably used in amounts ranging from 0.01 wt% to 2 wt%. Alternatively, preservatives may be used in amounts of 2 to 8 wt%, more preferably 3 to 6 wt%, when the composition is in the form of a concentrated powder.

[0055] Diluents other than water can include liquid or solid emollients, solvents, humectants, thickeners and powders. Examples of each of these types of vehicles, which can be used alone or as a mixture of one or more vehicles, are as follows:

[0056] Emollients such as stearyl alcohol, glyceryl monoricinoleate, mink oil, cetyl alcohol, isopropyl isostearate, stearic acid, isobutyl palmitate, isocetyl stearate, oleyl alcohol, isopropyl laurate, hexyl laurate, decyl oleate, octadecane-2-ol, isocetyl alcohol, eicosanyl alcohol, behenyl alcohol, cetyl palmitate, silicone oils such as dimethylpolysiloxane, di-n-butyl sebacate, isopropyl myristate, palmitate Isopropyl Myristate, Isopropyl Stearate, Butyl Stearate, Polyethylene Glycol, Triethylene Glycol, Lanolin, Cocoa Butter, Corn Oil, Cottonseed Oil, Olive Oil, Palm Kernel Oil, Rapeseed Oil, Safflower Seed Oil, Evening Primrose Oil, Soybean Oil, Sunflower Seed Oil, Avocado Oil, Sesame Oil, Coconut Oil, Peanut Oil, Castor Oil, Acetylated Lanolin Alcohol, Yellow Petrolatum, Mineral Oil, Butyl Myristate, Isostearic Acid, Palmitic Acid, Isopropyl Linoleate, Lauryl Lactate, Myristyl Lactate, Decyl Oleate, Myristyl Myristate.

[0057] Further, the composition preferably includes other optional ingredients such as antioxidants, fragrances, polymers, chelating agents, colorants, deodorants, dyes, emollients, moisturizers, enzymes, foam boosters, lathering agents, skin conditioners, pH adjusters and stabilizers that may be added in suitable amounts. Preferably, these ingredients are added after the saponification step. Sodium metabisulfite, ethylenediaminetetraacetic acid (EDTA), borax or ethylenehydroxydiphosphonic acid (EHDP) are preferably added to the formulation. Such ingredients may be present in the composition in an amount of 0-7 wt%, more preferably 1-5 wt%, and even more preferably 2-4 wt%.

[0058] In a second aspect, the present invention provides a method for providing an antimicrobial effect, comprising the steps of: a. applying a composition of the present invention to a surface; and b. Optionally, rinsing the surface to which the composition is applied. Also disclosed is a method comprising:

[0059] Step (a) involves applying the composition of the first aspect to a surface. The surface is preferably an inanimate or animate surface. More preferably, the surface is an animate surface, such as human skin. "Skin" as used herein is preferably meant to include the skin of any part of the body, such as the face, neck, chest, back, arms, armpits, hands, feet, buttocks and scalp.

[0060] Step (a) is preferably carried out by a user applying the composition of the first aspect to a surface together with a sufficient amount of water to create a lather.

[0061] The method optionally but preferably includes an additional step, step (b), in which the surface to which the composition is applied is at least partially rinsed with water to remove the composition from the surface. Preferably, step (b) of at least partially removing the composition is carried out less than 5 minutes, more preferably less than 3 minutes, even more preferably less than 1 minute, even more preferably less than 35 seconds, e.g., within 10, 20 or 30 seconds, after step (a). Preferably, the method is of a non-therapeutic and / or cosmetic nature.

[0062] When the composition is in the form of a concentrated powder, preferably, an appropriate amount of concentrated powder, for example 5 grams, is mixed with an appropriate amount of diluent, preferably water, for example 100 mL, before carrying out step (a). It is also understood that the step of rehydrating the concentrated powder or carrying out the dilution needs to be carried out once, and only after that, 100 mL of such liquid cleaning composition is used by the end user. Such dilution can be carried out in any container, for example a bottle, preferably with a stopper or cap to seal the container, and the volume of the bottle is sufficient to hold the diluted amount, for example 100 mL. Preferably, a container suitable for this rehydration step can be supplied with the concentrated powder. More preferably, such a container is equipped with a dispensing function with a pump to facilitate dispensing of the liquid cleaning composition formed. The container can be filled with a diluent, for example water, first, and then the concentrated powder composition is added, or vice versa. After the concentrated powder and the diluent are added to a suitable container, it is preferable to seal the container and shake it for about 15 to 60 seconds. The freshly reconstituted liquid composition is preferably allowed to stand for at least 30 minutes, preferably at least 1-2 hours.

[0063] In the method of the second aspect, the liquid composition so prepared is applied to a surface as described in step (a) above, optionally but preferably followed by step (b) as described above.

[0064] In a third aspect, the present invention relates to the use of a composition as described in the first aspect to provide an antimicrobial benefit, such as an antibacterial benefit. The composition of the present invention provides an antimicrobial effect. Preferably, the use is of a non-therapeutic and / or cosmetic nature.

[0065] In a fourth aspect, the present invention relates to the use of an ammonium salt as an antimicrobial efficacy enhancer of a solid cleaning composition comprising a carboxylic acid having a pKa in the range of 2.5 to 4.5, wherein the pH of a 5% solution of the composition is in the range of 2.5 to 6.5. Preferably, the use is of a non-therapeutic and / or cosmetic nature.

[0066] Various features of the invention referred to in individual sections above apply mutatis mutandis to other sections, where appropriate. Thus, features specified in one section may be combined with features specified in other sections, where appropriate. Any section headings are added for convenience only and are not intended to limit the disclosure in any way.

[0067] The invention will now be further illustrated by the following non-limiting examples. EXAMPLES

[0068] Protocol The following protocol was used to evaluate the cidial activity. IN-VITRO TIME-KILL PROTOCOL - ASTM 2783

[0069] Preparation of bacterial culture: In these experiments, Escherichia coli ATCC 10536 was used in this study, which represents a Gram-negative bacterium. Bacteria were grown overnight on Tryptic soya agar (TSA) plates. Bacterial cell density was then adjusted to a pre-calibrated optical density at 620 nm by using a spectrophotometer to obtain a final count of 10 in saline (0.86% NaCl).9 cfu / mL was obtained.

[0070] Assay Protocol 9.9 mL of different example compositions (described in Table 1 below) were taken in different sample containers at specific product dilutions. To each of these containers, 0.1 mL of bacterial culture was added immediately before performing the assay and mixed thoroughly to obtain a mixture. Immediately after adding the culture, a timer was started. The mixture was allowed to maintain specific contact for 10 seconds to 30 seconds, for example 20 seconds.

[0071] At the end of each contact time, the antimicrobial activity of the samples was immediately neutralized by adding 1 mL of each of the above mixtures to 9 mL of the appropriate neutralization broth validated for this test system. The neutralized samples were then serially diluted up to 5 dilutions in neutralization broth and plated in duplicate on TSA (40 gpL - Difco).

[0072] Log reduction was calculated by comparison with a bacterial control. The bacterial control used for this purpose was a mixture prepared by adding 0.1 mL of bacterial culture to 9.9 mL of saline, and then the mixture was serially diluted and plated on TSA. After solidification of the TSA plates, the plates were incubated at 37°C for 48 hours. The colonies on the plates were counted.

[0073] A log reduction of greater than 5 means a 99.99% reduction in CFU counts, a log reduction of less than 0.5 means no reduction in CFU counts, which means no antimicrobial efficacy. A log reduction of greater than 5 also represents complete kill.

[0074] Powdered samples of carboxylic acid, surfactant and ammonium salt in the amounts shown in the table below were mixed in a pestle and mortar, then structurant and polymer, if present, were added in the amounts shown in the table below.

[0075] The compositions shown in Table 1 below were prepared.

[0076] [Table 1]

[0077] The above data demonstrate that the composition of the present invention (Example 1) exhibits synergistic antimicrobial efficacy.

Claims

1. a. 2 to 15 wt. % of an ammonium salt selected from ammonium chloride, ammonium benzoate, ammonium citrate, ammonium carbonate, ammonium acetate, ammonium sulfate, isopropylammonium chloride, and mixtures thereof; and b. 2-25 wt. % of one or more carboxylic acids having a pKa in the range of 2.5-4.5 1. A solid cleaning composition comprising: A solid cleaning composition, wherein a 5% solution of said composition has a pH in the range of 2.5 to 6.

5.

2. 2. The composition of claim 1, wherein the ammonium salt is selected from ammonium chloride, ammonium citrate, and mixtures thereof.

3. 2. The composition of claim 1, wherein the carboxylic acid is selected from aromatic carboxylic acids, cyclic carboxylic acids, aliphatic carboxylic acids, and mixtures thereof.

4. 2. The composition of claim 1, wherein the carboxylic acid is selected from aromatic carboxylic acids selected from benzoic acid, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, or aliphatic carboxylic acids selected from citric acid, lactic acid, and mixtures thereof.

5. 2. The composition of claim 1, wherein the carboxylic acid is benzoic acid.

6. 10. The composition of claim 1, further comprising 10 to 80 wt. % of an anionic surfactant.

7. 7. The composition of claim 6, wherein the anionic surfactant is selected from alkyl sulfates, alkyl sulfosuccinates, alkyl sulfoacetates, alkyl ether sulfates, isethionates, taurates, and mixtures thereof.

8. 10. The composition of claim 1, further comprising one or more essential oils selected from thymol, terpineol, carvacrol, eugenol, menthol, and mixtures thereof.

9. 9. The composition of claim 8, further comprising a structuring agent selected from silica, talc, kaolinite, bentonite, starch, cellulose, feldspar, mica, and mixtures thereof.

10. 13. The composition of claim 1 in the form of a bar.

11. 10. The composition of claim 1 in the form of a powder or a concentrated powder.

12. 1. A method for providing an antimicrobial effect, comprising: a. applying the composition of any one of claims 1 to 11 to a surface; and b. Optionally, rinsing the surface to which the composition is applied. The method includes:

13. 13. The method of claim 12, wherein the step of rinsing the surface is performed within 5 minutes of applying the composition to the surface.

14. 12. Use of a composition according to any one of claims 1 to 11 to provide an antimicrobial effect.

15. 1. Use of an ammonium salt as an antimicrobial efficacy enhancer in a solid cleaning composition comprising a carboxylic acid having a pKa in the range of 2.5 to 4.5, wherein the pH of a 5% solution of said composition is in the range of 2.5 to 6.5.

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