WO2020223959A1

WO2020223959A1 - Stable anti-mite liquid laundry detergent composition comprising benzyl benzoate

Info

Publication number: WO2020223959A1
Application number: PCT/CN2019/086192
Authority: WO
Inventors: Fangfang FENG; Yijia CAO; Hongling Chen
Original assignee: The Procter & Gamble Company
Priority date: 2019-05-09
Filing date: 2019-05-09
Publication date: 2020-11-12
Also published as: JP6957676B2; CN111909798B; CN111909798A; JP2020186378A

Abstract

A stable anti-mite liquid laundry detergent composition comprising from 1 wt% to 10 wt% of benzyl benzoate, which is stabilized by from 0.03 wt% to 1 wt% of a non-polymeric, crystalline, hydroxyl-containing structuring agent.

Description

STABLE ANTI-MITE LIQUID LAUNDRY DETERGENT COMPOSITION COMPRISING BENZYL BENZOATE

FIELD OF THE INVENTION

This invention is related to a liquid laundry detergent composition, preferably a stable liquid laundry detergent composition comprising benzyl benzoate in an amount sufficient to provide an anti-mite benefit.

BACKGROUND OF THE INVENTION

Dust mites may be one of the most prevalent indoor allergens. They are potentially responsible for from 50 to 80 percent of all asthma cases, and countless cases of eczema, hay fever and other allergic reactions. Dust mites can burrow and cling to fabrics, mostly in carpet, household upholstery, mattress, beddings, and sometimes clothing.

Correspondingly, it is desirable to provide fabric treatment compositions with anti-mite benefits. Benzoic acid esters, such as benzyl benzoate, are known as effective anti-mite agents. However, because benzyl benzoate is insoluble in water, its incorporation into liquid fabric treatment compositions, especially into aqueous detergent compositions, has been challenging.

On one hand, benzyl benzoate, when used at relatively low amounts (e.g., below 1%) , can be emulsified to form relatively small droplets that can be stably dispersed in an aqueous detergent composition. However, benzyl benzoate at such low amounts may not be sufficient to deliver the desired anti-mite efficacy. On the other hand, when used at greater amounts in order to support the desired anti-mite benefit (e.g., 1%or above) , benzyl benzoate may coagulate to form larger droplets, which in turn causes phase separation of the aqueous detergent composition over time and/or under stressed conditions.

There is therefore a need to provide liquid detergent compositions, especially aqueous laundry detergent compositions, containing a sufficiently high amount of benzyl benzoate for delivering the desired anti-mite benefit, which are phase stable over time and/or under stressed conditions.

SUMMARY OF THE INVENTION

The present invention provides a liquid detergent composition, and preferably an aqueous laundry detergent composition, which comprises:

(a) from about 1%to about 10%, preferably from about 2%to about 8%, preferably from about 3%to about 6%, of benzyl benzoate by total weight of said composition; and

(b) from about 0.03%to about 1%, preferably from about 0.04%to about 0.8%, more preferably from about 0.1%to about 0.5%, of a non-polymeric, crystalline, hydroxyl-containing structuring agent by total weight of said composition.

Preferably, said non-polymeric, crystalline, hydroxyl-containing structuring agent is hydrogenated castor oil. More preferably, said non-polymeric, crystalline, hydroxyl-containing structuring agent is present as crystals having a non-spherical elongated crystal habit with an aspect ratio of at least about 5: 1 and a needle radius of at least about 20 nanometers.

In a preferred but not necessary embodiment of the present invention, the non-polymeric, crystalline, hydroxyl-containing structuring agent is provided in a structuring premix that further comprises an anionic surfactant.

For example, said structuring premix may comprise: (i) from about 1%to about 10%, preferably from about 2%to about 8%, more preferably from about 3%to about 5%, of said non-polymeric, crystalline, hydroxyl-containing structuring agent by total weight of said structuring premix; (ii) from about 1%to about 10%, preferably from about 2%to about 8%, more preferably from about 3%to about 5%, of an alkanolamine by total weight of said structuring premix; (iii) from about 5%to about 50%, preferably from about 10%to about 30%, more preferably from about 12%to about 20%, of a C ₁₀-C ₂₀ linear alkyl benzene sulphonic acid (HLAS) by total weight of said structuring premix; and (iv) water, wherein said alkanolamine is present in an amount at least balancing the charge of the HLAS; and wherein said structuring premix is free from any added inorganic cations. Example of suitable alkanolamines include monoethanolamine, diethanolamine, triethanolamine, and mixtures thereof. Preferably, the alkanolamine is monoethanolamine.

For another example, said structuring premix comprises: (i) from about 0.2%to about 35%, preferably from about 2%to about 20%, of said non-polymeric, crystalline, hydroxyl-containing structuring agent by total weight of said structuring premix; (ii) from about 1%to about 45%, preferably from about 8%to about 29%, of a C ₁₀-C ₂₀ alkyl sulphate by total weight of said structuring premix; and (iii) water.

The liquid detergent composition of the present invention is an aqueous laundry detergent composition that further comprises:

(c) from about 5%to about 40%of anionic surfactant by total weight of said composition;

(d) from about 2%to about 25%of nonionic surfactant by total weight of said composition; and

(e) from about 0.5%to about 15%of fatty acid by total weight of said composition.

These and other features of the present invention will become apparent to one skilled in the art upon review of the following detailed description when taken in conjunction with the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the articles "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 “comprising, ” “comprises, ” "include" , "includes" and "including" are meant to be non-limiting.

As used herein, the term “substantially free of” or “substantially free from” means that the indicated material is present in an amount of no more than about 5 wt%, preferably no more than about 2%, and more preferably no more than about 1 wt%.

As used therein, the term “essentially free of” or “essentially free from” means that the indicated material is at the very minimal not deliberately added to the composition, or preferably not present at an analytically detectible level in such composition. It may include compositions in which the indicated material is present only as an impurity of one or more of the materials deliberately added to such compositions.

As used herein, the term “liquid” refers to a fluid having a liquid having a viscosity of from about 1 to about 2000 mPa*sat 25℃ and a shear rate of 20 sec- ¹. In some embodiments, the viscosity of the liquid may be in the range of from about 200 to about 1000 mPa*sat 25℃ at a shear rate of 20 sec- ¹. In some embodiments, the viscosity of the liquid may be in the range of from about 200 to about 500 mPa*sat 25℃ at a shear rate of 20 sec- ¹.

All temperatures herein are in degrees Celsius (℃) unless otherwise indicated. Unless otherwise specified, all measurements herein are conducted at 25℃ and under the atmospheric pressure. In all embodiments of the present invention, all percentages are by weight of the total composition, unless specifically stated otherwise. All ratios are weight ratios, unless specifically stated otherwise.

It is understood that the test methods that are disclosed in the Test Methods Section of the present application must be used to determine the respective values of the parameters of Applicants’ inventions are described and claimed herein.

Benzyl Benzoate

Benzyl benzoate has been known to have anti-mite benefit when used at a relatively high concentration, e.g., at least about 1%, preferably from about 1%to about 20%, more preferably from about 2%to about 15%, most preferably from about 3%to about 10%, by total weight of the liquid detergent composition into which benzyl benzoate is formulated.

Because benzyl benzoate is insoluble in water, it is preferably combined with sufficient solvent to maintain a stable dispersion in the aqueous mixture. The aqueous benzyl benzoate mixture can be an emulsion of a colloidal dispersion of benzyl benzoate in water and/or solvent.

Structuring Agent and Premix Thereof

It is particularly preferred that the benzyl benzoate is formulated into a liquid detergent composition that contains at least one non-polymeric, crystalline, hydroxyl-containing structuring agent for stabilizing the colloidal dispersion of benzyl benzoate.

Such non-polymeric, crystalline, hydroxyl-containing structuring agent typically can be selected from the group consisting of:

i)

wherein R ¹ is -C (O) R ⁴, R ² is R ¹ or H, R ³ is R ¹ or H, and R ⁴ is independently C ₁₀-C ₂₂ alkyl or alkenyl comprising at least one hydroxyl group;

ii)

wherein:

R ⁷ is

R ⁴ is as defined above in i) ;

M is Na ⁺, K ⁺, Mg ⁺⁺ or Al ³⁺, or H; and

iii) mixtures thereof.

Alternatively, the non-polymeric, crystalline, hydroxyl-containing stabilizing agent may have the formula:

Wherein (x + a) is from between 11 and 17; (y + b) is from between 11 and 17; and (z + c) is from between 11 and 17. Preferably, wherein x = y = z =10 and/or wherein a = b = c = 5.

Most preferably, the structuring agent is selected from castor oil, castor oil derivatives, especially hydrogenated castor oil (HCO) derivatives, for example, castor wax, and mixtures thereof. Highly preferred esters include triesters of 12-hydroxyoctadecanonic acid, though mono and diesters can also be present. It is preferred that the hydroxyl-containing material does not have ethoxylated or propoxylated components or moieties. Commercially available crystalline, hydroxyl-containing stabilizing agents include

from Rheox, Inc.

Without intending to be limited by theory, the crystalline, hydroxyl-containing structuring agents are agents which form a thread-like structuring network when crystallized within a liquid matrix. This network reduces the tendency of materials within the liquid wherein the network forms, to coalesce and/or phase split. It is believed that the thread-like structuring system forms a fibrous or entangled threadlike network in-situ on cooling of the matrix. The thread-like structuring system can have an average aspect ratio of from about 1.5: 1, preferably from at least about 10: 1, to about 200: 1. The thread-like structuring system can be made to have a viscosity of about 2000 cstks or less at an intermediate shear range (5 s ^-1 to 50 s ^-1) which allows the processing of a system while the low shear viscosity of the product at 0.1 s ^-1 can be at least about 2000 cstks but more preferably greater than about 20,000 cstks.

In a preferred embodiment of the present invention, the crystalline, hydroxyl-containing structuring agent is provided as a structuring premix that further comprises an anionic surfactant. Anionic surfactant may be present in the structuring premix of the present invention at any suitable weight percentage of the total system. Without wishing to be bound by theory, it is believed that the anionic surfactant acts as an emulsifier of melts of HCO and similarly crystallizable glycerides. As used herein “anionic surfactant” in preferred embodiments does not include soaps and fatty acids; they may be present in the final laundry detergent compositions, but in general, other than limited amounts of 12-hydroxystearic acid which may arise from limited hydrolysis of hydrogenated castor oil glycerides, are not deliberately included in the structuring premix. For overall formula accounting purposes, “soaps” and “fatty acids” are accounted as builders. Otherwise, any suitable anionic surfactant is of use in the structuring premix of present invention.

Preferred anionic surfactants for the structuring premix herein possess what is termed “low Krafft temperatures” . The term "Krafft temperature" as used herein is a term of art which is well-known to workers in the field of surfactant sciences. “Krafft temperature” for the present purposes is measured by taking the sodium salt of an anionic surfactant having a single chainlength; and measuring the clearing temperature of a 1 wt%solution of that surfactant. Alternative well-known art techniques include Differential Scanning Calorimetry (DSC) . Preferred embodiments of the present invention employ structuring premix containing anionic surfactants for which the corresponding sodium salt has a Krafft temperature below about 50℃, more preferably, below about 40℃, more preferably still, below about 30℃, or below about 20℃, or below 0℃.

Non-limiting examples of suitable anionic surfactants of use herein include: linear alkyl benzene sulphonates (LAS) , alkyl sulphates (AS) , alkyl ethoxylated sulphonates (AES) , laureth sulfates, and mixtures thereof. In some embodiments, the anionic surfactant may be present in the structuring premix at a level of from about 5%to about 50%. Note however, that when using more than about 25%by weight of the structuring premix of an anionic surfactant, it is typically required to thin the surfactant using an organic solvent in addition to water.

Further, when selecting the anionic surfactant for the structuring premix, and an alkylbenzene sulfonate surfactant is chosen for this purpose, it is preferred to use any of (1) alkylbenzene sulfonates selected from HF-process derived linear alkylbenzenes and/or (2) mid-branched LAS (having varying amounts of methyl side-chains) . Other preferred LAS sources include (3) those available from Cepsa LAB; and (4) those available from UOP LAB. In contrast, LAS derived from DETAL ^TM process (UOP, LLC, Des Plaines, IL) process and/or LAS having high 2-phenyl content as taught by Huntsman are preferably avoided for use in the structuring premix, although they may be incorporated into the final laundry detergent compositions. Without intending to be limited by theory, excessive 2-phenyl isomer content leads to undesirably high melting temperatures of the LAS.

For example, the structuring premix may comprise a melt of the above-mentioned non-polymeric, crystalline, hydroxyl-containing structure agent (including, but not limited to HCO) in an aqueous medium comprising at least a partially lower alkanolamine-neutralized linear alkylbenzene sulfonate (LAS) . The melt of said non-polymeric, crystalline, hydroxyl-containing structure agent is in the form of an emulsion or microemulsion, with the LAS acting as an emulsifier. For purposes of clarity, it should be understood that “alkanolamine neutralized” means that the counter-ion of the anionic surfactant LAS is the cationic form or cation form of the alkanolamine. This alkanolamine is not acting as a solvent or as a buffer. The emulsion is cooled to crystallize the structuring agent. This yields an external structurant in the form of an alkanolamine-containing, sodium-free premix, which can be shipped as an article of commerce, or can be directly added to the balance of a liquid laundry detergent composition. In this embodiment, the anionic surfactant is not used in its sodium-neutralized form; more generally, the anionic surfactant is not used in the form of any monovalent or divalent inorganic cationic salt such as the sodium, potassium, lithium, magnesium, or calcium salts. Preferably, the structuring premix and the laundry detergents herein comprise less than about 5%, 2%or 1%of monovalent inorganic cations such as sodium or potassium. In a preferred embodiment, no (i.e., 0%) in total of monovalent and/or divalent inorganic metal ions whatsoever are added to the structuring premix, and no soap is deliberately added in making the structuring premix. In other words, the structuring premix is substantially free from monovalent and/or divalent inorganic metal ions. In a particularly preferred embodiment of the present invention, the structuring premix may comprise the following by weight percentage:

(i) from about 1%to about 10%, preferably from about 2%to about 8%, more preferably from about 3%to about 5%, of said non-polymeric, crystalline, hydroxyl-containing structuring agent by total weight of said structuring premix;

(ii) from about 1%to about 10%, preferably from about 2%to about 8%, more preferably from about 3%to about 5%, of an alkanolamine by total weight of said structuring premix;

(iii) from about 5%to about 50%, preferably from about 10%to about 30%, more preferably from about 12%to about 20%, of a C ₁₀-C ₂₀ linear alkyl benzene sulphonic acid (HLAS) by total weight of said structuring premix; and

(iv) water,

wherein said alkanolamine is present in an amount at least balancing the charge of the HLAS; and wherein said structuring premix is free from any added inorganic cations.

Alkanolamine is an essential component the above-described structuring premix. Without wishing to be bound by theory, it is believed that alkanolamine reacts with the acid form anionic surfactant species to form an alkanolamine neutralized anionic surfactant. As such, alkanolamine can be introduced into the premix either by combining alkanolamine and acid-form anionic surfactant, e.g., HLAS in-situ in the premix, or by any other suitable means such as by separately neutralizing HLAS with alkanolamine and adding the neutral alkanolamine-LAS to the premix. However, in some embodiments it may be desirable that alkanolamine be present in the structuring premix of the invention in stoichiometric excess over the amount required to neutralize the acid form of the anionic surfactants. In such embodiments, the alkanolamine may serve the dual purpose of acting as part of the emulsifying surfactant and as a buffer.

In general, any suitable alkanolamine or mixture of alkanolamines may be of use in the present invention. Suitable alkanolamines may be selected from the lower alkanol mono-, di-, and trialkanolamines, such as monoethanolamine; diethanolamine or triethanolamine. Higher alkanolamines have higher molecular weight and may be less mass efficient for the present purposes. Mono-and di-alkanolamines are preferred for mass efficiency reasons. Monoethanolamine is particularly preferred, however an additional alkanolamine, such as triethanolamine, can be useful in certain embodiments as a buffer. Moreover, it is envisioned that in some embodiments of the invention, alkanolamine salts of anionic surfactants other than the aliquots used in the structuring premix can be added separately to the final detergent formulation, for example for known purposes such as solvency, buffering, the management of chlorine in wash liquors, and/or for enzyme stabilization in laundry detergent products.

For another example, the structuring premix may comprise a melt of the above-mentioned non-polymeric, crystalline, hydroxyl-containing structure agent (including, but not limited to HCO) in an aqueous medium comprising an alkyl sulfate surfactant, which is added as an emulsifying agent. The alkyl sulphate surfactant is preferably added at a concentration above the critical micelle concentration (c.m.c) of the surfactant. When the non-polymeric, crystalline, hydroxyl-containing structuring agent is emulsified into an aqueous phase containing these micelles, a portion of the non-polymeric, crystalline, hydroxyl-containing structuring agent is transferred to the micelles, to form droplets that are stabilised by the micelles. The alkyl sulphate surfactant may be present in the structuring premix at a level of from about 1%to about 45%, preferably from about 4%to about 37%, more preferably from about 8%to about 29%, most preferably from about 8%to about 24%by weight of the structuring premix. The weight percentage of alkyl sulphate surfactant is measured, based on the weight percentage of the surfactant anion. That is, excluding the counterion. When using more than about 25%by weight of the structuring premix of an anionic surfactant, it is preferred to thin the surfactant using an organic solvent, in addition to water.

Preferred alkyl sulphate surfactants are selected from the group consisting of: C ₁₀-C ₂₀ alkyl sulphate, and mixtures thereof; preferably C ₁₀-C ₁₈ alkyl sulphate, and mixtures thereof; more preferably C ₁₂-C ₁₄ alkyl sulphate, and mixtures thereof; most preferably sodium dodecyl sulphate. The alkyl sulphate surfactant is preferably non-ethoxylated, non-propoxylate or combinations thereof. The alkyl sulphate surfactant is typically present in the form of their salts with alkanolamines or alkali metals such as sodium and potassium. Preferably, the alkyl sulphate surfactant is neutralized with alkanolamines, such as monoethanolamine or triethanolamine, and are fully soluble in the continuous phase.

In a particularly preferred embodiment of the present invention, the structuring premix may comprise the following by weight percentage:

(i) from about 0.2%to about 35%, preferably from about 2%to about 20%, of said non-polymeric, crystalline, hydroxyl-containing structuring agent by total weight of said structuring premix;

(ii) from about 1%to about 45%, preferably from about 8%to about 29%, of a C ₁₀-C ₂₀ alkyl sulphate by total weight of said structuring premix; and

(iii) water.

Other Ingredients

In addition to the benzyl benzoate and the non-polymeric, crystalline, hydroxyl-containing structuring agent described hereinabove, the liquid detergent composition of the present invention may comprise one or more detersive actives selected from the group consisting of surfactants, enzymes, optical brighteners, dye transfer inhibition agents, suds suppressors, detersive soil release polymers, other benefit agents, and combinations of these adjunct types. All of these materials are of the type conventionally utilized in the detergent products, especially laundry detergent products. They can, however, be delivered to aqueous washing liquors, and/or to fabrics being laundered therein, especially effectively via the compositions of the present invention.

The liquid detergent compositions herein will essentially contain from about 5%to about 70%by weight, preferably from about 7%to about 65%by weight, more preferably from about 10%to about 50%by weight, of a certain kind of detersive surfactant component. Such an essential detersive surfactant component must comprise anionic surfactants, nonionic surfactants, or combinations of these two surfactant types.

Suitable anionic surfactants useful herein can comprise any of the conventional anionic surfactant types typically used in liquid detergent products, including those described hereinabove for emulsifying the structuring agent in the structuring premix.

Suitable nonionic surfactants useful herein can comprise any of the conventional nonionic surfactant types typically used in liquid detergent products. These include alkoxylated fatty alcohols, ethylene oxide (EO) -propylene oxide (PO) block polymers, and amine oxide surfactants. Preferred for use in the liquid detergent products herein are those nonionic surfactants which are normally liquid.

Preferred nonionic surfactants for use herein include the alcohol alkoxylate nonionic surfactants. Alcohol alkoxylates are materials which correspond to the general formula:

R ¹ (C _mH _2mO) _nOH

wherein R ¹ is a C ₈-C ₁₆ alkyl group, m is from about 2 to about 4, and n ranges from about 2 to about 12. Preferably R ¹ is an alkyl group, which may be primary or secondary, that contains from about 9 to about 15 carbon atoms, more preferably from about 10 to about 14 carbon atoms. Preferably also the alkoxylated fatty alcohols will be ethoxylated materials that contain from about 2 to about 12 ethylene oxide moieties per molecule, more preferably from about 3 to about 10 ethylene oxide moieties per molecule. Suitable alkoxylated fatty alcohol nonionic surfactants have been marketed under the tradenames

and

by the Shell Chemical Company.

Another type of nonionic surfactant which may be utilized in the compositions of this invention comprises the ethylene oxide (EO) -propylene oxide (PO) block polymers. Materials of this type are well known nonionic surfactants which have been marketed under the tradename Pluronic. These materials are formed by adding blocks of ethylene oxide moieties to the ends of polypropylene glycol chains to adjust the surface active properties of the resulting block polymers.

Yet another suitable type of nonionic surfactant useful herein comprises the amine oxide surfactants. Amine oxides are mateials which are often referred to in the art as “semi-polar” nonionics. Amine oxides have the formula: R (EO) _x (PO) _y (BO) _zN (O) (CH ₂R') ₂. qH ₂O. In this formula, R is a relatively long-chain hydrocarbyl moiety which can be saturated or unsaturated, linear or branched, and can contain from about 8 to about 20, preferably from about 10 to about 16 carbon atoms, and is more preferably C ₁₂-C ₁₆ primary alkyl. R' is a short-chain moiety preferably selected from hydrogen, methyl and -CH ₂OH. When x+y+z is different from 0, EO is ethyleneoxy, PO is propyleneneoxy and BO is butyleneoxy. Amine oxide surfactants are illustrated by C _12-14 alkyldimethyl amine oxide.

In the liquid detergent composition herein, the essential detersive surfactant component may comprise combinations of anionic and nonionic surfactant materials. When this is the case, the weight ratio of anionic to nonionic will typically range from about 100: 1 to about 1: 100, more typically from about 20: 1 to about 1: 20. In a particularly preferred embodiment of the present invention, the liquid detergent composition further comprises (in addition to benzyl benzoate and the structuring agent described hereinabove) :

The liquid laundry detergent compositions herein may comprise one or more detersive enzymes which provide cleaning performance and/or fabric care benefits. Examples of suitable enzymes include, but are not limited to, hemicellulases, peroxidases, proteases, cellulases, xylanases, lipases, phospholipases, esterases, cutinases, pectinases, keratanases, reductases, oxidases, phenoloxidases, lipoxygenases, ligninases, pullulanases, tannases, mannanases? , pentosanases, malanases, β-glucanases, arabinosidases, hyaluronidase, chondroitinase, laccase, and known amylases, or combinations thereof. A preferred enzyme combination comprises a cocktail of conventional detersive enzymes like protease, lipase, cutinase and/or cellulase in conjunction with amylase. If employed, enzymes will normally be incorporated into the liquid laundry detergent compositions herein at levels sufficient to provide up to about 10 mg by weight, more typically from about 0.01 mg to about 5 mg, of active enzyme per gram of the composition. Stated otherwise, the aqueous liquid detergent compositions herein can typically comprise from about 0.001%to about 5%, preferably from about 0.01%to about 1%by weight, of a commercial enzyme preparation. Protease enzymes, for example, are usually present in such commercial preparations at levels sufficient to provide from about 0.005 to about 0.1 Anson units (AU) of activity per gram of detergent composition.

The liquid laundry detergent compositions herein may comprise one or more optical brighteners which provide fabric treatment benefits. Such materials, also known as fluorescent whiting agents (FWAs) , are generally deposited onto fabrics or garments being laundered and alter the optical or chromaticity characteristics of the substrates so treated. Preferred optical brighteners are anionic in character. Many are stilbene derivatives. If employed, optical brighteners will typically be incorporated into the liquid laundry detergent compositions herein in concentrations ranging from about 0.01%to about 1%, preferably from about 0.05%to about 0.5%, by weight.

The liquid laundry detergent compositions herein may comprise one or more dye transfer inhibition agents which permit desirable laundering of colored fabrics. Suitable polymeric dye transfer inhibiting agents include, but are not limited to, polyvinylpyrrolidone polymers, polyamine N-oxide polymers, copolymers of N-vinylpyrrolidone and N-vinylimidazole, polyvinyloxazolidones and polyvinylimidazoles or mixtures thereof. If employed, dye transfer inhibiting agents will typically be incorporated into the liquid laundry detergent compositions herein in concentrations ranging from about 0.0001%, more preferably from about 0.01%, most preferably from about 0.03%by weight to about 10%, more preferably to about 2%, most preferably to about 1%by weight.

The liquid laundry detergent compositions herein may comprise one or more materials which act as suds suppressors to minimize over-sudsing of the compositions herein when they are employed for laundering of fabrics in automatic washing machines. Frequently, suds suppressor systems are based on silicones or silica-silicone combinations. If employed, suds suppressors will typically be incorporated into the liquid laundry detergent compositions herein in concentrations ranging from about 0.001%to about 2%by weight. More preferably, suds suppressors can comprise from about 0.01%to about 1%by weight of the compositions herein.

The liquid laundry detergent compositions herein may comprise one or more detersive soil release polymers which provide fabric treatment benefits. Polymeric soil release agents useful in the present invention include copolymeric blocks of terephthalate and polyethylene oxide or polypropylene oxide, and the like. A preferred soil release agent is a copolymer having blocks of terephthalate and polyethylene oxide. More specifically, these polymers are comprised of repeating units of ethylene and/or propylene terephthalate and polyethylene oxide terephthalate at a molar ratio of ethylene terephthalate units to polyethylene oxide terephthalate units of from about 25: 75 to about 35: 65. This polyethylene oxide terephthalate contains polyethylene oxide blocks having molecular weights of from about 300 to about 2000. The molecular weight of this polymeric soil release agent is in the range of from about 5,000 to about 55,000. If employed, soil release polymers will typically be incorporated into the liquid laundry detergent compositions herein in concentrations ranging from about 0.01%to about 10%, more preferably from about 0.1%to about 5%, by weight of the composition.

In addition to the ingredients hereinbefore described, the laundry washing adjunct component of the compositions herein may also comprise additional benefit agents which can be deposited onto fabrics being laundered and which thereupon provide one or more types of fabric care or treatment benefits. Such benefits can include, for example, fabric softness, anti-static effects, ease-of-ironing benefits, anti-abrasion benefits, anti-pilling effects, color protection, wrinkle removal or improved resistance to wrinkling, fabric substantive perfume or odor benefits, malodor protection benefits, and the like. If employed, such additional fabric care benefit agents polymers can typically be incorporated into the liquid laundry detergent compositions herein in concentrations ranging from about 0.05%to about 20%, by weight, depending upon the nature of the materials to be deposited and the benefit (s) they are to provide. More preferably, such fabric care benefit agents can comprise from about 0.1%to about 10%, by weight of the composition.

EXAMPLES

Example 1: Comparative Examples Showing Phase Stability of Liquid Laundry Detergent Compositions Containing Benzyl Benzoate (BB) with Different Levels of HCO-Containing Structuring Premix

A structuring premix is first formed, which contains the following ingredients:

Table 1

Ingredients	Wt%
Monoethanolamine (MEA)	3.2
C ₁₂-C ₁₄ Linear Alkyl Benzene Sulphonic acid (HLAS)	16
Hydrogenated castor oil (HCO)	4
Preservatives	0.2
Water	Balance

Different levels of such HCO-containing structuring premix are then formulated into respective liquid laundry detergent compositions (A) - (I) together with 3%benzyl benzoate (BB) , as follows:

Table 2

*Miscellaneous ingredients include builders, chelants, dyes, enzymes, solvents, suds suppressors, perfumes, etc.

Phase stability of each of the above-described liquid laundry detergent compositions (A) - (I) is then tested according to the following steps:

· Dose 15-40 mL of the sample liquid laundry detergent composition into a 20-40 mL transparent glass bottle;

· Put the glass bottle into low-temperature (-5℃, -3℃, 0℃) ovens for stability test;

· Check appearance of the samples at any different time points (e.g., 1, 8, 12, 13wks) ;

· Take samples out of the low-temperature ovens and wait for the sample temperature to return back to room temperature (～25℃) . The sample temperature typically returns within 6-24 hours after the sample is taken out of the low-temperature oven;

· Check sample appearance under normal lamp light; and

· If a specific sample looks homogeneous and isotropic as the freshly made sample, then record a “pass” for the phase stability test; if the sample shows small oil droplet inside, or big oil aggregates, or complete separation into 2 phases, then record a “fail” for the phase stability test.

Following are the recorded phase stability results of the liquid laundry detergent compositions (A) - (I) :

Table 3

	A	B	C	D	E	F	G	H	I
HCO (wt%)	0.02	0.034	0.047	0.059	0.08	0.1	0.12	0.16	0.2
Phase stability at 0℃/12 weeks	Pass	Pass	Pass	Pass	Pass	Pass	Pass	Pass	Pass
Phase stability at -3℃/12 weeks	Fail	Pass	Pass	Pass	Pass	Pass	Pass	Pass	Pass
Phase stability at -5℃/13 weeks	Fail	Fail	Pass	Pass*	Pass*	Pass	Pass	Pass	Pass

*There are slight signs of oil droplets observed, which may be caused by sample making and sampling variation.

The varying HCO levels demonstrate impact on phase stability of the 3%BB-containing liquid laundry detergent compositions. When a sample similar to the above listed is substantially free of HCO (not shown here) , it is not phase stable even at room temperature and starts to show white floccules after 16 hours at Room temperature. However, when the sample contains HCO at a level that is above 0.03%, it is phase stable at -3℃ for 12 weeks. When the HCO level arises above 0.04%, the sample is phase stable at -5℃ for 13 weeks.

Further, BB may form liquid crystals with surfactants in the above-described samples. The liquid crystal size correlates with phase stability of the samples. Typically, the smaller the liquid crystal size, the better the phase stability. Such liquid crystals are visible under microscope, as follows:

· Using a 3.0 mL dropper to dose one drop of the sample onto a glass slide.

· Put a cover slip on top of the glass slide over the sample drop;

· Observe the glass slide under a polarized light microscope (Olympus EX51) ;

· Identify the liquid crystal (lamella phase) in the sample drop and change the polarized light microscope to the normal light microscope;

· Adding the scale with 20X magnification times and capture a picture of the sample.

The liquid crystal sizes can then be observed from the sample pictures. Following are the observed liquid crystal sizes of several above-mentioned liquid laundry detergent compositions:

Table 4

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

A liquid laundry detergent composition comprising:

(a) from 1%to 20%of benzyl benzoate by total weight of said liquid detergent composition; and

(b) from 0.03%to 1%of a non-polymeric, crystalline, hydroxyl-containing structuring agent by total weight of said liquid detergent composition.
The liquid laundry detergent composition of claim 1, comprising from 2%to 15%, preferably 3%to 10%, of benzyl benzoate by total weight of said liquid detergent composition.
The liquid laundry detergent composition of claim 1 or 2, wherein said non-polymeric, crystalline, hydroxyl-containing structuring agent is hydrogenated castor oil; wherein preferably said non-polymeric, crystalline, hydroxyl-containing structuring agent is present as crystals having a non-spherical elongated crystal habit with an aspect ratio of at least 5: 1 and a needle radius of at least 20 nanometers.
The liquid laundry detergent composition according to any one of the preceding claims, comprising from 0.04%to 0.8%, preferably from 0.1%to 0.5%, of said non-polymeric, crystalline, hydroxyl-containing structuring agent.
The liquid laundry detergent composition according to any one of the preceding claims, wherein said non-polymeric, crystalline, hydroxyl-containing structuring agent is provided in a structuring premix that further comprises an anionic surfactant.
The liquid laundry detergent composition of claim 5, wherein said structuring premix comprises:

(i) from 1%to 10%, preferably from 2%to 8%, more preferably from 3%to 5%, of said non-polymeric, crystalline, hydroxyl-containing structuring agent by total weight of said structuring premix;

(ii) from 1%to 10%, preferably from 2%to 8%, more preferably from 3%to 5%, of an alkanolamine by total weight of said structuring premix;

(iii) from 5%to 50%, preferably from 10%to 30%, more preferably from 12%to 20%, of a C ₁₀-C ₂₀ linear alkyl benzene sulphonic acid (HLAS) by total weight of said structuring premix; and

(iv) water,

wherein said alkanolamine is present in an amount at least balancing the charge of the HLAS; and wherein said structuring premix is free from any added inorganic cations.
The liquid detergent composition of claim 6, wherein said alkanolamine is selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, and mixtures thereof; and wherein preferably said alkanolamine is monoethanolamine.
The liquid detergent composition according to claim 5, wherein said structuring premix comprises:

(i) from 0.2%to 35%, preferably from 2%to 20%, of said non-polymeric, crystalline, hydroxyl-containing structuring agent by total weight of said structuring premix;

(ii) from 1%to 45%, preferably from 8%to 29%, of a C ₁₀-C ₂₀ alkyl sulphate by total weight of said structuring premix; and

(iii) water.
The liquid detergent composition according to any one of the preceding claims, further comprising:

(c) from 5%to 40%of anionic surfactant by total weight of said liquid detergent composition;

(d) from 2%to 25%of nonionic surfactant by total weight of said liquid detergent composition; and

(e) from 0.5%to 15%of fatty acid by total weight of said liquid detergent composition.