WO2019071500A1

WO2019071500A1 - Anti-microbial laundry detergent composition

Info

Publication number: WO2019071500A1
Application number: PCT/CN2017/105798
Authority: WO
Inventors: Haiyan Song; Li LV; Mai NIKI; Xiujun Xu
Original assignee: The Procter & Gamble Company
Priority date: 2017-10-12
Filing date: 2017-10-12
Publication date: 2019-04-18
Also published as: CN109652230A; WO2019071994A1; JP6749378B2; CN109652230B; JP2019073688A

Abstract

An anti-microbial laundry detergent composition comprising, by weight of the composition, an anti-microbial agent that is a diphenyl ether, an amphoteric surfactant that is a C₆-C₂₀ alkyldimethyl amine oxide (AO), and an anionic surfactant that is a C₆-C₂₀ linear alkylbenzene sulfonate (LAS), while the LAS is present as the main surfactant of the composition. The laundry detergent composition characterized by such a surfactant system with AO and a high LAS content enables improved deposition of such anti-microbial agent onto treated fabrics.

Description

ANTI-MICROBIAL LAUNDRY DETERGENT COMPOSITION

FIELD OF THE INVENTION

The present invention relates to an anti-microbial laundry detergent composition.

BACKGROUND OF THE INVENTION

Consumer products have evolved to address user needs for an anti-microbial benefit, in addition to their original intended functions. For example, an anti-microbial laundry detergent product is desired by users as it cleans fabrics whilst having an anti-microbial benefit on fabrics. Currently, various anti-microbial agents, e.g., diphenyl ethers, are known for use in consumer product formulations to deliver an anti-microbial effect.

However, in context of laundry detergent products, it is challenging to achieve a desired deposition rate of the anti-microbial agents onto fabrics. Specifically, during a washing cycle, most of the active ingredients, including the anti-microbial agents, are eventually washed away along with the washing solution. Such, only a small amount of anti-microbial agents can be deposited onto washed fabrics, and therefore the actual anti-microbial effect of these laundry detergents is quite limited. Correspondingly, a larger amount of anti-microbial agents is typically needed in the laundry detergent products to compensate for such low deposition rate and to ensure that the resulting products has a desired anti-microbial efficacy. Such increased amount of anti-microbial agents in the laundry detergent products inevitably increases the manufacturing costs and processing complexity of such products.

Thus, there is a need for laundry detergent compositions that enable improved deposition of the anti-microbial agents onto the fabrics.

SUMMARY OF THE INVENTION

It is a surprising and unexpected discovery of the present invention that incorporation of a relatively small amount of an amphoteric surfactant, particularly a C₆-C₂₀ alkyldimethyl amine oxide (AO) , into a laundry detergent composition can significantly improve the deposition rate of diphenyl ether-based anti-microbial agents onto washed fabrics. Such improvement in the anti-microbial deposition rate is further boosted by the employment of a surfactant system that contains a C₆-C₂₀ linear alkylbenzene sulfonate surfactant as the main surfactant.

Correspondingly, the present invention in one aspect relates to an anti-microbial laundry detergent composition, comprising:

a) from about 0.05％to about 3％by weight of the composition, of an anti-microbial agent selected from the group consisting of diphenyl ethers and combinations thereof；

b) from about 0.05％to about 10％by weight of the composition, of an amphoteric surfactant selected from the group consisting of C₆-C₂₀ alkyldimethyl amine oxides (AO) and combinations thereof； and

c) from about 5％to about 50％by weight of the composition, of an anionic surfactant selected from the group consisting of C₆-C₂₀ linear alkylbenzene sulfonates (LAS) and combinations thereof, while such anionic surfactant ispresent as the main surfactant of the composition.

Preferably, the anti-microbial agent is a hydroxyl diphenyl ether of formula (I) :

while:

each Y is independently selected from chlorine, bromine, or fluorine,

each Z is independently selected from SO₂H, NO₂, or C₁-C₄ alkyl,

r is 0, 1, 2, or 3,

o is 0, 1, 2, or 3,

p is 0, 1, or 2,

m is 1 or 2, and

n is 0 or 1.

More preferably, the anti-microbial agent is selected from the group consisting of 4-4’-dichloro-2-hydroxy diphenyl ether, 2, 4, 4’-trichloro-2’-hydroxy diphenyl ether, and a combination thereof. Most preferably, the anti-microbial agent is 4-4’-dichloro-2-hydroxy diphenyl ether. The anti-microbial agent can be present in the anti-microbial laundry detergent composition of the present invention at an amount ranging from about 0.05％to about 1％, preferably from about 0.07％to about 0.5％, by weight of the composition.

The amphoteric surfactant useful for practice of the present invention can be readily selected from the group consisting of C₁₀-C₁₆ alkyldimethyl amine oxides and combinations thereof. Preferably, the amphoteric surfactant is selected from the group consisting of dodecyldimethyl amine oxide, tetradecyldimethyl amino oxide, and a combination thereof. More preferably, the amphoteric surfactant is dodecyldimethyl amine oxide. Such amphoteric surfactant can be present in the anti-microbial laundry detergent composition of the present invention at an amount ranging from about 0.1％to about 5％, preferably from about 0.2％to about 2％, by weight of the composition.

The anionic surfactant suitable for use in the present invention can be selected from the group consisting of C₁₀-C₁₆ linear alkylbenzene sulfonates and combinations thereof. Preferably, such anionic surfactant is selected from the group consisting of C₁₂-C₁₄ linear alkylbenzene sulfonates and a combination thereof. The anionic surfactant can be present in the anti-microbial laundry detergent composition of the present invention at an amount ranging from about 6％to about 30％, preferably from about 8％to about 20％, by weight of the composition. More preferably, such anionic surfactant is present as the majority surfactant in the anti-microbial laundry detergent composition of the present invention.

In a particularly preferred embodiment of the present invention, the anti-microbial laundry detergent composition comprises:

a) from about 0.07％to about 0.5％by weight of the composition, of the anti-microbial agent, which is 4-4’-dichloro-2-hydroxy diphenyl ether；

b) from about 0.2％to about 2％by weight of the composition, of the amphoteric surfactant, which is dodecyldimethyl amine oxide； and

c) from about 8％to about 20％by weight of the composition, of the anionic surfactant, which is a C₁₂ linear alkylbenzene sulfonate, while such anionic

surfactant is present as the majority surfactant in the composition.

In another aspect, the present invention relates to a method of pretreating or treating a soiled fabric comprising contacting the soiled fabric with the anti-microbial laundry detergent composition as mentioned hereinabove.

DETAILED DESCRIPTION OF THE INVENTION

Definitions

As used herein, the articles including “a” and “an” when used in a claim, are understood to mean one or more of what is claimed or described.

As used herein, the terms “comprise” , “comprises” , “comprising” , “include” , “includes” , “including” , “contain” , “contains” , and “containing” are meant to be non-limiting, i.e., other steps and other ingredients which do not affect the end of result can be added. The above terms encompass the terms “consisting of” and “consisting essentially of” .

As used herein, when a composition is “substantially free” of a specific ingredient, it is meant that the composition comprises less than a trace amount, alternatively less than 0.1％, alternatively less than 0.01％, alternatively less than 0.001％, by weight of the composition, of the specific ingredient.

As used herein, the term “laundry detergent composition” means a composition for cleaning soiled materials, including fabrics. Such compositions may be used as a pre-laundering treatment, a post-laundering treatment, or may be added during the rinse or wash cycle of the laundering operation. The laundry detergent composition compositions may have a form selected from liquid, powder, single-phase or multi-phase unit dose, pouch, tablet, gel, paste, bar, or flake. Preferably, the laundry detergent composition is a liquid. The term “liquid laundry detergent composition” herein refers to compositions that are in a form selected from the group consisting of pourable liquid, gel, cream, and combinations thereof. The liquid laundry detergent composition may be either aqueous or non-aqueous, and may be anisotropic, isotropic, or combinations thereof.

As used herein, the term “anti-microbial agent” refers to a chemical compound of which the principle intended function is to kill bacteria or to prevent their growth or reproduction. Traditional anti-microbial agents include cationic anti-microbial agents (e.g., certain ammonium chlorides) , nonionic anti-microbial agents, etc. Diphenyl ether compounds that are used in the present invention are nonionic anti-microbial agents.

As used herein, the term “main surfactant” refers to a surfactant that is present in a composition at an amount that is greater than any other surfactant contained by such composition.

As used herein, the term “majority surfactant” refers to a surfactant that is present in a composition at an amount that is at least 50％by weight of the total surfactant content in such composition.

As used herein, the term "alkyl" means a hydrocarbyl moiety which is branched or unbranched, substituted or unsubstituted. Included in the term "alkyl" is the alkyl portion of acyl groups.

As used herein, the term “washing solution” refers to the typical amount of aqueous solution used for one cycle of laundry washing, preferably from 1 L to 50 L, alternatively from 1 L to 20 L for hand washing and from 20 L to 50 L for machine washing.

As used herein, the term “soiled fabric” is used non-specifically and may refer to any type of natural or artificial fibers, including natural, artificial, and synthetic fibers, such as, but not limited to, cotton, linen, wool, polyester, nylon, silk, acrylic, and the like, as well as various blends and combinations.

Anti-microbial Laundry Detergent Composition

The anti-microbial laundry detergent composition of the present invention comprises an anti-microbial agent of diphenyl ether in a specific surfactant system, which comprises an amphoteric surfactant (preferably AO) and an anionic surfactant (preferably LAS) , while preferably the anionic surfactant is present as the main surfactant, more preferably as the majority surfactant, in such composition. It has been surprisingly found that, by utilizing such a specific surfactant system with AO, and particularly with a relatively high LAS content, deposition rate of the anti-microbial agent onto treated fabrics is significantly enhanced.

Preferably in the laundry detergent composition, the anti-microbial agent is present from about 0.05％to about 3％, more preferably from about 0.05％to about 1％, most preferably from about 0.07％to about 0.5％, by weight of the composition. The amphoteric AO surfactant is preferably present in the composition at an amount ranging from about 0.05％to about 10％, more preferably from about 0.1％to about 5％, most preferably from about 0.2％to about 2％, by weight of the composition. The anionic LAS surfactant is preferably present in the composition at an amount ranging from about 5％to about 50％, more preferably from about 6％to about 30％, most preferably from about 8％to about 20％, by weight of the composition. Furthermore, the anionic LAS surfactant is present as the main surfactant of the composition, or preferably as the majority surfactant of the composition, e.g., at no less than about 40％, preferably no less than about 50％, more preferably no less than about 55％, most preferably no less than 60％, and up to about 99％, preferably up to about 95％, more preferably up to about 90％, by weight of the total surfactant content of the composition.

In a laundry washing solution, the laundry detergent composition is preferably capable of delivering the anti-microbial agent at a level from about 0.01 ppm to about 5 ppm, more preferably from about 0.05 ppm to about 3 ppm, more preferably from about 0.1 ppm to about 1 ppm.

The laundry detergent composition herein provides anti-microbial benefits against both Gram positive bacteria (e.g., Staphylococcus aureus) and Gram negative bacteria (e.g., Klebsiella pneumoniae) . The composition preferably provides residual anti-microbial benefits to the fabrics treated by the composition, i.e., the nonionic anti-microbial agent therein deposits onto the fabrics during a washing cycle and subsequently the deposited (i.e., residual) antimicrobial-agent prevents bacteria growth onto the fabrics during drying or storage or wear. In one embodiment, the laundry detergent composition provides a Bacteriostatic Activity Value of at least a log 2.2 reduction, preferably a log 2.5 reduction, against both Gram positive bacteria and Gram negative bacteria, to treated fabrics versus non-treated fabrics. Preferably, the composition provides at least a log 2.2 reduction, preferably a log 2.5 reduction, against Staphylococcus aureus and/or Klebsiella pneumoniae after a 10 minutes contact time in a 1055 ppm aqueous solution as determined by the JISL 1902 method (that is described below) . More preferably, the composition provides at least a log 3.0 reduction, preferably a log 3.5 reduction, against Staphylococcus aureus. It is worth noting that Staphylococcus aureus is frequently found on human skin and therefore fabrics (particularly wearing fabrics) are in particular need of anti-microbial effects against Staphylococcus aureus.

The laundry detergent composition herein may be acidic or alkali or pH neutral, depending on the ingredients incorporated in the composition. The pH range of the laundry detergent composition is preferably from about 4 to about 12, more preferably from about 6 to about 11, even more preferably from about 7 to about 10.

The laundry detergent composition can have any suitable viscosity depending on factors such as formulated ingredients and purpose of the composition. In one embodiment, the composition has a high shear viscosity value, at a shear rate of 20/sec and a temperature of 21℃, of about 200 to about 3,000 cP, alternatively about 300 to about 2,000 cP, alternatively about 500 to about 1,000 cP, and a low shear viscosity value, at a shear rate of 1/sec and a temperature of 21℃, of about 500 to about 100,000 cP, alternatively about 1000 to about 10,000 cP, alternatively about 1,500 to about 5,000 cP.

Diphenyl Ether-Based Anti-microbial Agent

The diphenyl ether-based anti-microbial agent of the present invention is a nonionic compound. In the present invention, it has been found that due to its nonionic property, the anti-microbial agent of the present invention allows for a stable liquid anti-microbial laundry detergent composition. By contrast, cationic anti-microbial agents are typically not compatible with anionic surfactants present in the laundry detergent compositions.

Preferably, the anti-microbial agent is a hydroxyl diphenyl ether. The anti-microbial agent herein can be either halogenated or non-halogenated, but preferably is halogenated. In one embodiment, the anti-microbial agent is a hydroxyl diphenyl ether of formula (I) :

wherein:

each Y is independently selected from chlorine, bromine, or fluorine, preferably is chlorine or bromine, more preferably is chlorine,

each Z is independently selected from SO₂H, NO₂, or C₁-C₄ alkyl,

r is 0, 1, 2, or 3, preferably is 1 or 2,

o is 0, 1, 2, or 3, preferably is 0, 1 or 2,

p is 0, 1, or 2, preferably is 0,

m is 1 or 2, preferably is 1, and

n is 0 or 1, preferably is 0.

In the above definition for formula (I) , 0 means nil. For example, when p is 0, then there is no Z in formula (I) . Each Y and each Z could be the same or different. In one embodiment, o is 1, r is 2, and Y is chlorine or bromine. This embodiment could be: one chlorine atom bonds to a benzene ring while the bromine atom and the other chlorine atom bond to the other benzene ring； or the bromine atom bonds to a benzene ring while the two chlorine atoms bond to the other benzene ring.

More Preferably, the anti-microbial agent is selected from the group consisting of 4-4’-dichloro-2-hydroxy diphenyl ether ( “Diclosan” ) , 2, 4, 4’-trichloro-2’-hydroxy diphenyl ether ( “Triclosan” ) , and a combination thereof. Most preferably, the anti-microbial agent is 4-4’-dichloro-2-hydroxy diphenyl ether, commercially available from BASF, under the trademark name

In addition to the diphenyl ether, other anti-microbial agents may also be present, provided that these are not present at a level which causes instability in the formulation. Among such useful further antimicrobial agents are chelating agents, which are particularly useful in reducing the resistance of Gram negative microbes in hard water. Acid biocides may also be present.

Amphoteric Surfactant (AO)

The amphoteric surfactant suitable for use in the present invention can be selected from the group consisting of C₆-C₂₀ alkyldimethyl amine oxides (AO) and combinations thereof.

Preferably, the amine oxide surfactant is characterized by the following structure:

where R¹ is a C_6-20 alkyl, a C_6-20 hydroxyalkyl, or a C_6-20 alkyl phenyl group； each R² is a C_2-5 alkylene, or a C_2-5 hydroxyalkylene group； x is from 0 to about 3； and each R³ is a C_1-3 alkyl, a C_1-3 hydroxyalkyl, or a polyethylene oxide containing from about 1 to about 3 ethoxylene (EO) units. Preferably, the amine oxide surfactant may be a C_8-18 alkyldimethyl amine oxide, preferably a C_10-16 alkyldimethyl amine oxide.

Preferably, the amphoteric surfactant is selected from the group consisting of dodecyldimethyl amine oxide, tetradecyldimethyl amino oxide, and a combination thereof. More preferably, the amphoteric surfactant contains dodecyldimethyl amino oxide having the following formula (II) :

Such a compound is also referred to as lauryldimethyl amine oxide or dodecydimethyl amine-N-oxide (DDAO) . It is commercially available from Huntsman under the tradename

It has been a surprising and unexpected discovery of the present invention that a relatively small amount of the AO surfactant, e.g., from about 0.05％to about 10％, or from about 0.1％to about 5％, or from about 0.2％to about 2％, in the laundry detergent composition can significantly improves the deposition rate of the diphenyl ether anti-microbial agent onto washed fabrics. Without being bound by any theory, it is believed that the AO surfactant may modify the micelle structure in the washing solution formed by the laundry detergent composition of the present invention, thereby to drive deeper penetration of the diphenyl ether anti-microbial agent into the fabrics and to improve the overall deposition rate of such ant-microbial agent on washed fabrics.

Anionic Surfactant (LAS)

The C₆-C₂₀ linear alkylbenzene sulfonate surfactant (LAS) is a required surfactant for the laundry detergent composition of the present invention. In one embodiment, LAS is C₁₀-C₁₆ LAS, preferably C₁₂-C₁₄ LAS.

The LAS is normally prepared by sulfonation (using SO₂ or SO₃) of alkylbenzenes followed by neutralization. Suitable alkylbenzene feedstocks can be made from olefins, paraffins or mixtures thereof using any suitable alkylation scheme, including sulfuric and HF-based processes. By varying the precise alkylation catalyst, it is possible to widely vary the position of covalent attachment of benzene to an aliphatic hydrocarbon chain. Accordingly, the LAS herein can vary widely in 2-phenyl isomer and/or internal isomer content.

In the laundry detergent composition, the level of LAS is preferably higher than that of any other surfactant contained by such composition, i.e., the LAS is the main surfactant in such composition. More preferably, the LAS is present at an amount that is at least about 50％, or at least about 55％, by weight of the total surfactant content in such composition. Such a LAS-rich or LAS-dominant surfactant system further boosts deposition of the diphenyl ether anti-microbial agent onto washed fabrics, in comparison with other surfactant systems enriched by or dominated by other surfactants, such as C₆-C₂₀ alkyl alkoxy sulfates (AE_xS) and nonionic surfactants, as discussed hereinafter.

Other Surfactants

In addition to the amphoteric surfactants and the LAS surfactants described hereinabove, the laundry detergent composition of the present invention may comprise one or more other surfactants, such as other anionic surfactants (i.e., other than LAS) , nonionic surfactants, other amphoteric surfactants (i.e., other than AO) , cationic surfactants, and zwitterionic surfactants, provided that the content of each of such other surfactants is lower than that of the LAS surfactant. Preferably, the total content of all other surfactants is lower than that of the LAS surfactant.

For example, the laundry detergent composition may contain a C₆-C₂₀ alkyl alkoxy sulfates (AE_xS) , wherein x is about 1-30, preferably about 1-15, more preferably about 1-10, most preferably x is about 1-3. The alkyl chain in such AE_xS can be either linear or branched, with mid-chain branched AE_xS surfactants being particularly preferred. A preferred group of AE_xS include C₁₂-C₁₄ alkyl alkoxy sulfates with x of about 1-3. The amount of AE_xS surfactant (s) in the laundry detergent composition of the present invention may range from about 0.05％to about 30％, preferably from about 0.1％to about 20％, more preferably from about 0.5％ to about 15％, most preferably from about 1％to about 5％, by weight of the composition. Without being bound by any theory, it is believed that a higher level of AE_xS may not help, but may actually have an adverse impact on, the deposition of the anti-microbial agent onto washed fabrics, so it is desirable to keep the AE_xS content in the laundry detergent composition of the present invention relatively low.

The laundry detergent composition may contain an alkoxylated nonionic surfactant. Non-limiting examples of alkoxylated nonionic surfactants suitable for use herein include: C₁₂-C₁₈ alkyl ethoxylates, such as

nonionic surfactants available from Shell； C₆-C₁₂ alkyl phenol alkoxylates wherein the alkoxylate units are a mixture of ethyleneoxy and propyleneoxy units； C₁₂-C₁₈ alcohol and C₆-C₁₂ alkyl phenol condensates with ethylene oxide/propylene oxide block alkyl polyamine ethoxylates such as

available from BASF； C₁₄-C₂₂ mid-chain branched alkyl alkoxylates, BAEx, wherein x is from about 1 to about 30； alkylpolysaccharides, specifically alkylpolyglycosides； polyhydroxy fatty acid amides； and ether capped poly (oxyalkylated) alcohol surfactants. Also useful herein as nonionic surfactants are alkoxylated ester surfactants such as those having the formula R¹C (O) O (R₂O) nR³ wherein R¹ is selected from linear and branched C₆-C₂₂ alkyl or alkylene moieties； R² is selected from C₂H₄ and C₃H₆ moieties and R³ is selected from H, CH₃, C₂H₅ and C₃H₇ moieties； and n has a value between about 1 and about 20. Such alkoxylated ester surfactants include the fatty methyl ester ethoxylates (MEE) and are well-known in the art.

In a particular embodiment, the alkoxylated nonionic surfactant contained by the laundry detergent composition of the present invention is a C₆-C₂₀ alkoxylated alcohol, preferably C₈-C₁₈ alkoxylated alcohol, more preferably C₁₀-C₁₆ alkoxylated alcohol. The C₆-C₂₀ alkoxylated alcohol is preferably an alkyl alkoxylated alcohol with an average degree of alkoxylation of from about 1 to about 50, preferably from about 3 to about 30, more preferably from about 5 to about 20, even more preferably from about 5 to about 9. The alkoxylation herein may be ethoxylation, propoxylation, or a mixture thereof, but preferably is ethoxylation. In one embodiment, the alkoxylated nonionic surfactant is C₆-C₂₀ ethoxylated alcohol, preferably C₈-C₁₈ alcohol ethoxylated with an average of about 5 to about 20 moles of ethylene oxides, more preferably C₁₀-C₁₆ alcohol ethoxylated with an average of about 5 to about 9 moles of ethylene oxides. The most preferred alkoxylated nonionic surfactant is C₁₂-C₁₅ alcohol ethoxylated with an average of about 7 moles of ethylene oxide, e.g.,

commercially available from Shell.

The amount of nonionic surfactant (s) in the laundry detergent composition of the present invention may range from about 0.1％to about 30％, preferably from about 0.5％to about 25％, more preferably from about 1％to about 20％, most preferably from about 5％to about 10％, by weight of the composition.

In a highly preferred embodiment, the anti-microbial laundry detergent composition of the present invention comprises:

1) from about 0.07％to about 0.5％, by weight of the composition, of the anti-microbial agent, which is 4-4’-dichloro-2-hydroxy diphenyl ether；

2) from about 0.2％to about 2％by weight of the composition, of the amphoteric surfactant, which is dodecyldimethyl amine oxide；

3) from about 8％to about 20％by weight of the composition, of the anionic surfactant, which is a C₁₂-C₁₄ LAS and which is present as the majority surfactant of such composition LAS；

4) from about 1％to about 5％by weight of the composition, of another anionic surfactant, which is a C₁₂-C₁₄ AE_xS with x of about 1-3； and

5) from about 5％to about 10％by weight of the composition, of a nonionic surfactant (NI) , which is a C₁₂-C₁₅ alcohol ethoxylated with an average of about 7 moles of ethylene oxide.

In this embodiment, the weight ratio of LAS to AE_xS is preferably at least 2: 1, preferably at least 3: 1, more preferably at least 5: 1, most preferably at least 7: 1. The weight ratio of LAS to NI may be at least 1.25: 1, preferably at least 1.5: 1, more preferably at least 1.6: 1.

The laundry detergent composition of the present invention may further comprise a cationic surfactant. Non-limiting examples of cationic surfactants include: quaternary ammonium surfactants, which can have up to 26 carbon atoms include: alkoxylate quaternary ammonium (AQA) surfactants； dimethyl hydroxyethyl quaternary ammonium； dimethyl hydroxyethyl lauryl ammonium chloride； polyamine cationic surfactants； and amino surfactants, specifically amido propyldimethyl amine (APA) .

The laundry detergent composition of the present invention may further comprise another amphoteric surfactant (i.e., besides AO) . Non-limiting examples of other amphoteric surfactants include: derivatives of secondary and tertiary amines, derivatives of heterocyclic secondary and tertiary amines, or derivatives of quaternary ammonium, quaternary phosphonium or tertiary sulfonium compounds. Preferred examples include: betaine, including alkyl dimethyl betaine and cocodimethyl amidopropyl betaine, sulfo and hydroxy betaines, such as N-alkyl-N, N-dimethylammino-1-propane sulfonate where the alkyl group can be C₈-C₁₈ or C₁₀-C₁₄.

Adjunct Ingredients

The laundry detergent composition herein may comprise adjunct ingredients. Suitable adjunct materials include but are not limited to: builders, chelating agents, rheology modifiers, dye transfer inhibiting agents, dispersants, enzymes, and enzyme stabilizers, catalytic materials, bleach activators, hydrogen peroxide, sources of hydrogen peroxide, preformed peracids, polymeric dispersing agents, clay soil removal/anti-redeposition agents, brighteners, suds suppressors, dyes, photobleaches, perfumes, perfume microcapsules, structure elasticizing agents, fabric softeners, carriers, hydrotropes, processing aids, solvents, hueing agents, structurants and/or pigments. The precise nature of these adjunct ingredients and the levels thereof in the laundry detergent composition will depend on the physical form of the composition and the nature of the cleaning operation for which it is to be used.

In one embodiment, the composition herein comprises a rheology modifier (also referred to as a “structurant” in certain situations) , which functions to suspend and stabilize certain particulate ingredients and to adjust the viscosity of the composition so as to be more applicable to the packaging assembly. The rheology modifier herein can be any known ingredient that is capable of suspending particles and/or adjusting rheology to a liquid composition. Preferably the rheology modifier is selected from the group consisting of hydroxy-containing crystalline material, polyacrylate, polysaccharide, polycarboxylate, alkali metal salt, alkaline earth metal salt, ammonium salt, alkanolammonium salt, C₁₂-C₂₀ fatty alcohol, di-benzylidene polyol acetal derivative (DBPA) , di-amido gallant, a cationic polymer comprising a first structural unit derived from methacrylamide and a second structural unit derived from diallyl dimethyl ammonium chloride, and a combination thereof. Preferably, the rheology modifier is a hydroxy-containing crystalline material generally characterized as crystalline, hydroxyl-containing fatty acids, fatty esters and fatty waxes, such as castor oil and castor oil derivatives. More preferably the rheology modifier is a hydrogenated castor oil (HCO) .

Composition Preparation

The laundry detergent composition of the present invention is generally prepared by conventional methods such as those known in the art of making laundry detergent compositions. Such methods typically involve mixing the essential and optional ingredients in any desired order to a relatively uniform state, with or without heating, cooling, application of vacuum, and the like, thereby providing laundry detergent compositions containing ingredients in the requisite concentrations.

Method of Use

Another aspect of the present invention is directed to a method of using the laundry detergent composition to treat a fabric with an anti-microbial benefit. The method comprises the step of administering from 5 g to 120 g of the above-mentioned laundry detergent composition into a laundry washing basin comprising water to form a washing solution. The washing solution in a laundry washing basin herein preferably has a volume from 1 L to 50 L, alternatively from 1 L to 20 L for hand washing and from 20 L to 50 L for machine washing. Preferably, the anti-microbial benefit herein is determined by the JISL 1902 method. The temperatures of the laundry washing solution preferably range from 5℃ to 60℃.

The dosing amount in the method herein may be different depending on the washing type. In one embodiment, the method comprises administering from about 5 g to about 60 g of the laundry detergent composition into a hand washing basin (e.g., about 2-4 L) . In an alternative embodiment, the method comprises administering from about 5 g to about 100 g, preferably from about 10 g to about 65 g of the laundry detergent composition into a washing machine (e.g., about 30-45 L) .

Preferably, the method herein further comprises the step of contacting a soiled fabric with the washing solution. For example, the presence of Gram positive bacteria and/or Gram negative bacteria is suspected on the fabric. The step of contacting the soiled fabric with the washing solution is preferably after the step of administering the laundry detergent composition in a laundry washing basin. The method may further comprise the step of contacting a fabric with the laundry detergent composition prior to the step of administering the laundry detergent composition in a laundry washing basin, i.e.， pre-treat the fabric with the laundry detergent composition for certain time, preferably from 1 minute to 10 minutes.

Test Method

Test 1: Fabric Deposition Test for Anti-Microbial Agents

Anti-microbial agents are extracted from treated fabrics by using the methanol-based Accelerated Solvent Extraction (ASE) method described hereinafter. The resulting extract is then subjected to gradient reversed-phase high performance liquid chromatographic (HPLC) separation on a C18 column and is quantified by tandem mass spectrometry (MS/MS) operating under multiple reaction monitoring (MRM) conditions at negative mode.

As a first step, about three (3) grams of the treated fabrics is accurately weighed and then filled into a steel ASE tube. The extraction protocol is run for about five (5) minutes using methanol as the extraction solvent at an elevated temperature of about 100℃ and a pressure of about 2000 pound per square inch (psi) . The resulting extract is collected and transferred into a 25-ml flask, which is then filled to its full volume with methanol. The resulting solution is then diluted by about twenty-five (25) fold by using a mixture of methanol and water at a 50: 50 ratio, which is used as an injection sample for the subsequent LC-MS/MS analysis.

Next, about five (5) ul of the above-mentioned injection sample is injected and separated on a Waters ACQUITY UPLC C18 column with gradient from about 70％mobile phase A (1％formic water solution) /30％mobile phase B (0.1％formic acid in methanol) to 5％mobile phase A/95％mobile phase B in about three (3) minutes, and the final gradient is kept for another three (3) minutes. The anti-microbial agent, for example

is detected at the negative MRM mode. The ion pair of m/z 253>142 is used as quantification transition, while m/z of 253>125 is used for identification.

Subsequently, spiked matrix standards in the range of 0.5mg/ml to 500ng/ml are injected for creation of a calibration curve. Concentration of the anti-microbial agent, for example

in the injection sample is determined by extrapolation using weighted (1/x²) quadratic regression of the calibration curve.

Test 2: Anti-Microbial Efficacy Test (JISL 1902)

The anti-microbial efficacy for laundry detergent compositions is determined by the method as defined in the JISL 1902 method and described hereinafter.

1. Microorganism Preparation:

A. Aseptically add certain amount of nutrient broth into a lyophilized culture of Staphylococcus aureus or Klebsiella pneumoniae. Dissolve and suspend the culture in the nutrient broth to obtain a suspension. Streak a loop of the suspension onto a nutrient agar plate, and incubate at 37℃ for 24 hours to obtain a first generation subculture of bacterial suspension. Transfer a loop of the first generation subculture of bacterial suspension into 20 mL of nutrient broth with shaking, and incubate at 37℃ for 24 hours to obtain a second generation subculture of bacterial suspension. Transfer 0.4 mL of the second generation subculture of bacterial suspension into another 20 mL of nutrient broth with shaking, and incubate at 37℃ for 3±1 hours to obtain a third generation subculture of bacterial suspension.

B. Dilute the third generation subculture of bacterial suspension by 1/20 diluted nutrient broth to 1×105 cells/mL to obtain a working culture.

C. Store the working culture at 4℃. The working culture cannot be stored overnight.

2. Fabric washing:

A. Boil two fabric strips each having a width of 1 m and length of 3 m (32 yarn/cm×32 yarn/cm, 100％plain weave cotton) in 5 L of a solution for 1 hour. The solution is prepared by 2.5 g of a nonionic soaked agent, 2.5 g of sodium carbonate, and 5000 mL of distilled water. The nonionic soaked agent is prepared by 5.0 g of alkylphenol ethoxylate, 5 g of sodium carbonate, and 1000 mL of distilled water. Rinse the fabric strips in boiled deionized water for 5 minutes. Place the fabric strips in cool deionized water for 5 minutes, and indoor dry. One fabric strip serves as a test fabric strip for following steps 2B–2I, and the other fabric strip is used as control (without experiencing steps 2B–2I) .

B. Fix one end of the test fabric strip obtained from step 2A onto a stainless steel spindle at an outer position along the horizontal extension of the stainless steel spindle. The stainless steel spindle has 3 horizontal stands that are connected to one another. Wrap the test fabric strip around the 3 horizontal stands of the stainless steel spindle with sufficient tension to obtain a fabric wrapped spindle having 12 laps of fabric. Fix the other end of the test fabric strip onto the outer lap of the 12 laps of fabric via a pin. Sterilize the fabric wrapped spindle with pressure steam at 121℃ for 15 minutes.

C. Dissolve 5.903 g of calcium chloride dihydrate and 2.721 g of magnesium chloride hexahydrate in 100 mL of distilled water, and then sterilize the mixture with pressure steam at 121℃ for 20 minutes. Add 1 mL of the mixture into 1L of distilled water to obtain a hard water solution.

D. Add sufficient amount of sample into 1L of the hard water solution obtained from step 2C to obtain a solution having a concentration of 1055 ppm. Mix the solution by a magnetic stirrer for 4 minutes. Distribute 250 mL of the mixed solution into an exposure chamber to obtain a washing solution. Place the exposure chamber in a water bath and achieve the test temperature of (25±1) ℃.

E. Aseptically soak the fabric wrapped spindle obtained from step 2B into the washing solution in the exposure chamber, and close the exposure chamber with a lid.

F. Fix the exposure chamber onto a tumbler. Rotate the tumbler for 10 minutes. Then remove the fabric wrapped spindle from the exposure chamber. Place the fabric wrapped spindle in Haier iwash-1p Top Load Washing Machine and spin-dry for 2 minutes.

G. Discard the washing solution from the exposure chamber, and then add 250 mL of sterilized distilled water into the exposure chamber. Soak the spin-dried fabric wrapped spindle in the newly added distilled water in the exposure chamber. Rotate the tumbler for 3 minutes and spin-dry for 2 minutes.

H. Repeat step 2G.

I. Aseptically remove the fabric wrapped spindle out of the exposure chamber and remove the test fabric strip from the spindle. Air dry the test fabric strip overnight.

3. Fabric Incubation:

A. Cut the washed test fabric strip obtained from step 2I to square pieces having a side length of 2 cm. Three (3) sets of 0.4 g of the pieces serve as specimens for the following steps.

B. Put each set of specimens into a vial, and then sterilize the specimens with pressure steam at 121℃ for 15 minutes. After the sterilization, dry the specimens for 1 hour in a clean bench without a cap.

C. Inoculate 0.2 mL of the working culture obtained from step 1C onto each dried specimen. Incubate the vials containing the inoculated specimens at 37℃ for 18 hours.

D. Extract survivors on the incubated specimens, plate with nutrient agar, and incubate at 37℃ for 24-48 hours. Count the total colony-forming units (CFU) of each set of specimens, and obtain average results of the 3 sets. Take the log10 value of CFU value as Mb.

E. In steps 3A –3D, use the fabric strip obtained from step 2A (that does not experience steps 2B –2I) as control. Take the log 10 value of CFU value as Ma.

4. Calculation of Bacteriostatic Activity Value:

Bacteriostatic Activity Value ＝ Mb-Ma

A Bacteriostatic Activity Value of no less than 2.0 represents acceptable anti-microbial efficacy, of no less than 2.5 represents good anti-microbial efficacy, and of no less than 3.0 represents excellent anti-microbial efficacy. And a Bacteriostatic Activity Value of lower than 2.0 indicates unacceptable poor anti-microbial efficacy.

EXAMPLES

Example 1: Comparative Test Showing Improved Fabric Deposition of Anti-Microbial Agent by Laundry Detergent Composition Containing Both AO and A High Level of LAS

Six (6) sample liquid laundry detergent compositions are prepared containing the following ingredients:

Table 1

a

is 4-4’-dichloro-2-hydroxy diphenyl ether, available from BASFb

is C₁₂-C₁₅ alcohol ethoxylated with an average of 7 moles of ethylene oxide as a nonionic surfactant, available from Shell

c Sodium salt of diethylene triamine penta acetic acid

The following fabric washing protocol is then executed by using each of the above-listed sample liquid laundry detergent compositions:

A. Add about forty-nine (49) liters of reverse osmosis (RO) water into a Haier TLA (XQS75-BYD1228) washing machine.

B. Add about 51.7 grams of the respective sample composition into the washing machine.

C. Add about 10 ml of a hardness solution into the washing machine. The hardness solution has a hardness level of about 3 gpg (Ca²⁺: Mg²⁺ ＝ 3: 1) , which is prepared by adding about 277.27 grams of CaCl₂·2H₂O and about 127.8 grams of MgCl₂·6H₂O into RO water to form a 1L stock solution.

D. Allow the sample composition to dissolve for about one minute.

E. Add eight (8) pieces of fabric tracers (cotton pieces of about 10cm×10cm each) with additional cotton pieces of the same size, to form a ballast of about 2.7 kg in total weight.

F. Wash the fabrics for about twelve (12) minutes at about 15-25℃, followed by draining of the water and spin-drying of the fabrics.

G. Add another forty-nine (49) liters of RO water into the washing machine to rinse for about three (3) minutes, by draining of the water and spin-drying of the fabrics.

H. Repeat Step (G) .

I. Take out the washed fabric tracers and ballast and machine-dry them for about one (1) hour.

J. Repeat Steps (A) to (I) three (3) times, while in the last repetition (i.e., the 4^th wash cycle) the fabric tracers are line-dried instead of machine-dried.

After the above fabric washing protocol is completed, the total amount of

deposited onto the fabric tracers is then measured by using the Fabric Deposition Test described hereinabove. The anti-microbial (AB) deposition result of each sample liquid laundry detergent composition is recorded as follows:

Table 2

The anti-microbial deposition rate is the highest when the sample liquid laundry detergent composition contains AO with a high LAS content, while in the absence of AO the sample liquid laundry detergent composition with a high AES content has the highest anti-microbial deposition rate. This indicates that AO in a high-LAS laundry detergent composition is particularly effective in boosting anti-microbial deposition onto fabrics.

Example 2: Exemplary Formulations of Liquid Laundry Detergent Compositions

The following liquid laundry detergent compositions shown in Table 3 are made comprising the listed ingredients in the listed proportions (weight ％) .

Table 3

Example 3: Exemplary Formulations of Liquid Laundry Detergent Compositions

The following liquid laundry detergent compositions shown in Table 4 are made comprising the listed ingredients in the listed proportions (weight ％) .

Table 4

The liquid laundry detergent compositions A-H in Examples 2 and 3 are prepared by the following steps:

a) mixing a combination of NaOH (if any) and water in a batch container by applying a shear of 200 rpm；

b) adding citric acid (if any) , boric acid (if any) , and C₁₁-C₁₃ LAS into the batch container, keeping on mixing by applying a shear of 200 rpm；

c) cooling down the temperature of the combination obtained in step b) to 25℃；

d) adding C_12-14AE_1-3S, Na-DTPA (if any) ,

dodecyldimethyl amine oxide, C₁₂-C₁₈ fatty acid, 1, 2 propanediol (if any) , monoethanolamine (if any) , calcium chloride (if any) , sodium cumene sulphonate (if any) , silicone emulsion (if any) , sodium polyacrylate (if any) , and

into the batch container, mixing by applying a shear of 250 rpm until the combination is homogeneously mixed, and adjusting pH to 8；

e) adding brightener (if any) , protease (if any) , amylase (if any) , dye (if any) , and perfume oil (if any) into the batch container, mixing by applying a shear of 250 rpm, thus forming a liquid laundry detergent composition,

wherein each ingredient in the composition is present in the level as specified for compositions A-H in Examples 2 and 3.

The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm. ”

Every document cited herein, including any cross referenced or related patent or application and any patent application or patent to which this application claims priority or benefit thereof, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.

While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims

An anti-microbial laundry detergent composition, comprising:

a) from 0.05％to 3％by weight of the composition, of an anti-microbial agent selected from the group consisting of diphenyl ethers and combinations thereof；

b) from 0.05％to 10％by weight of the composition, of an amphoteric surfactant selected from the group consisting of C₆-C₂₀ alkyldimethyl amine oxides (AO) and combinations thereof； and

c) from 5％to 50％by weight of the composition, of an anionic surfactant selected from the group consisting of C₆-C₂₀ linear alkylbenzene sulfonates (LAS) and combinations thereof, wherein said anionic surfactant is present as the main surfactant of said composition.
The anti-microbial laundry detergent composition according to Claim 1, wherein said anti-microbial agent is a hydroxyl diphenyl ether of formula (I) :

wherein:

each Y is independently selected from chlorine, bromine, or fluorine,

each Z is independently selected from SO₂H, NO₂, or C₁-C₄ alkyl,

r is 0, 1, 2, or 3,

o is 0, 1, 2, or 3,

p is 0, 1, or 2,

m is 1 or 2, and

n is 0 or 1,

wherein preferably said anti-microbial agent is selected from the group consisting of 4-4’ -dichloro-2-hydroxy diphenyl ether, 2, 4, 4’ -trichloro-2’ -hydroxy diphenyl ether, and a combination thereof, and wherein more preferably said anti-microbial agent is 4-4’ -dichloro-2-hydroxy diphenyl ether.
The anti-microbial laundry detergent composition according to Claim 1 or 2, wherein said anti-microbial agent is present in an amount ranging from 0.05％to 1％, preferably from 0.07％to 0.5％, by weight of the composition.
The anti-microbial laundry detergent composition according to any one of the preceding claims, wherein said amphoteric surfactant is selected from the group consisting of C₁₀-C₁₆ alkyldimethyl amine oxides and combinations thereof, and wherein preferably said amphoteric surfactant is selected from the group consisting of dodecyldimethyl amine oxide, tetradecyldimethyl amino oxide, and a combination thereof.
The anti-microbial laundry detergent composition according to any one of the preceding claims, wherein said amphoteric surfactant is present in an amount ranging from 0.1％to 5％, preferably from 0.2％to 2％, by weight of the composition.
The anti-microbial laundry detergent composition according to any one of the preceding claims, wherein said anionic surfactant is selected from the group consisting of C₁₀-C₁₆ linear alkylbenzene sulfonates and combinations thereof, and wherein preferably said anionic surfactant is selected from the group consisting of C₁₂-C₁₄ linear alkylbenzene sulfonates and a combination thereof.
The anti-microbial laundry detergent composition according to any one of the preceding claims, wherein said anionic surfactant is present in an amount ranging from 6％to 30％, preferably from 8％to 20％, by weight of the composition, and wherein preferably said anionic surfactant is present as the majority surfactant of said composition.
The anti-microbial laundry detergent composition according to Claim 1, comprising:

a) from 0.07％to 0.5％by weight of the composition, of said anti-microbial agent, wherein said anti-microbial agent is 4-4’ -dichloro-2-hydroxy diphenyl ether；

b) from 0.2％to 2％by weight of the composition, of said amphoteric surfactant, wherein said amphoteric surfactant is dodecyldimethyl amine oxide； and

c) from 8％to 20％by weight of the composition, of said anionic surfactant, wherein said anionic surfactant is a C₁₂ linear alkylbenzene sulfonate, and wherein said anionic surfactant is present as the majority surfactant of said composition.
A method of pretreating or treating a soiled fabric comprising contacting the soiled fabric with the anti-microbial laundry detergent composition according to any one of the preceding claims.