EP4653518A1

EP4653518A1 - Method of cleaning dishes

Info

Publication number: EP4653518A1
Application number: EP25161742.9A
Authority: EP
Inventors: Karl Ghislain Braeckman; Steven Jozef Louis Coosemans; Robby Renilde Francois Keuleers; Kelly Paula August Merckx; Pieter Jan Maria Saveyn; Evelyne Johanna Lutgarde Van Hecke
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 2024-05-24
Filing date: 2025-03-05
Publication date: 2025-11-26

Abstract

The need for a method of washing dishes at temperatures of 30 °C or less, at which the liquid detergent composition provides improved product dissolution and grease cleaning, is met by formulating the liquid hand dishwashing detergent composition to comprise a surfactant system, wherein the surfactant system comprises an alkyl polyglucoside surfactant which is a short chain alkyl polyglucoside surfactant.

Description

FIELD OF THE INVENTION

The present invention relates to methods of cleaning dishes.

BACKGROUND OF THE INVENTION

Hand dishwashing compositions should provide good grease cleaning and sudsing. Typically, dishes and the like are washed at elevated temperatures in order to more effectively clean dishes. In particular, greasy soils are softened at elevated temperatures. As such, dishes and the like are typically cleaned at temperatures of 35°C or higher.
However, there is a greater desire to wash dishes in a more sustainable manner, and more cost-effective manner. Heating the water used when washing dishes is one of the steps in the hand dishwashing process that is the least environmentally desirable, and is also one of the steps that adds most to the cost of washing dishes. As such, there is a greater desire to wash dishes at colder temperatures. However, there remains a high degree of scepticism from users that hand dishwashing detergents provide effective soil removal at low temperatures. One challenge is the generally poorer dissolution of liquid detergent compositions at lower temperatures, which increases the time needed to adequately wash dishware. In addition, sudsing is generally poorer in the presence of particulate soil, especially when combined with grease, and more especially during low temperature washing of dishware. It is believed that greases at lower temperatures are typically more solid and hence more challenging to solubilise, and as the grease and particulate is dispersed into the wash solution, sudsing is suppressed.
As such, a need remains for a method of washing dishes at temperatures of 30°C or less, at which the liquid detergent composition provides improved product dissolution, suds mileage and removal of greasy soils.
WO2017110773A1 relates to liquid detergent composition for hard surfaces, including dishware, and its use for cleaning the aforementioned hard surface at low temperatures. JP2013100461A discloses a liquid detergent composition hand-washing tableware at a low temperature (10 to 35 ° C.). WO201691688A relates to a liquid cleaning agent for hard surfaces, in particular for washing dishes by hand, containing an α amylase for cleaning starch stains at low temperature. JP2015010141A relates to a tableware washing detergent which provides detergency, foaming and rinsibility at low temperatures and aroma and reduced aroma variation at low temperatures. WO2014117973A relates to relates to anionic sulfonated cyclic surfactants of specific formula with lower cmc, for providing cleaning at low temperatures. EP3971270A relates to a liquid hand dishwashing cleaning compositions that comprise alkyl sulfate anionic surfactant having little or no ethoxylation, which provides improved low temperature stability while also achieving the desired product viscosity, suds mileage and overall cleaning. EP3971271A relates to a hand-dishwashing composition which is highly effective at removing grease, providing long-lasting suds under soiled conditions, while having a Newtonian viscosity which is less sensitive to changes on surfactant and solvent levels, the liquid hand dishwashing cleaning composition comprising a surfactant system having a combination of alkyl sulphate anionic surfactant having little or no alkoxylation and an alkyl polyglucoside surfactant. EP3971273A relates to a hand-dishwashing composition which is highly effective at removing grease, while also having good suds mileage, and avoiding negatives on physical stability, especially at low temperatures, the hand dishwashing composition comprising a surfactant system, the surfactant system comprising an alkyl sulfate anionic surfactant comprising little or no branching and having a low degree of alkoxylation, or no alkoxylation, and a co-surfactant, in combination with polypropylene glycol of a defined molecular weight, as described herein. EP3919594A relates to a liquid detergent composition suitable for washing dishes, fitting both in-sink as well as direct application habits, which provides reduced smearing when used in direct application dishwashing methods, while having good suds mileage especially under in-sink application habit, and good viscosity, the liquid detergent composition comprises a surfactant system, which comprises an alkyl sulfate anionic surfactant comprising C13 alkyl sulfate anionic surfactant, the C13 alkyl sulfate anionic surfactant comprising a specific fraction of 2-branched C13 alkyl sulfate anionic surfactant, with a specific distribution of the 2-branching. EP3971275A relates to a hand-dishwashing composition which is highly effective at emulsifying grease, the liquid hand dishwashing cleaning composition comprising a surfactant system having a combination of alkyl sulphate anionic surfactant and a co-surfactant comprising at least 70% by weight of the co-surfactant of a betaine, in combination with a polypropyleneglycol having a weight average molecular weight from 500 g/mol to 1800 g/mol. US2022081649A relates to a hand-dishwashing composition which is highly effective at removing grease, providing long-lasting suds under soiled conditions, while having a Newtonian viscosity which is less sensitive to changes on surfactant and solvent levels, the liquid hand dishwashing cleaning composition comprising a surfactant system having a combination of alkyl sulphate anionic surfactant having little or no alkoxylation and a blend of alkyl polyglucoside surfactant.

SUMMARY OF THE INVENTION

The present invention relates to a method of cleaning dishes, the method comprising the step of: contacting dishware with a liquid hand dishwashing detergent composition and water, wherein: the liquid hand dishwashing detergent composition comprises a surfactant system, wherein the surfactant system comprises: alkyl polyglucoside, wherein the alkyl polyglucoside consists of short-chain alkyl polyglucoside nonionic surfactant, wherein the short-chain alkyl polyglucoside nonionic surfactant has an average alkyl carbon chain length of from 8 carbon atoms to 10 carbon atoms and a number average degree of polymerization of from 0.5 to 3.0; the water has a temperature of 30 °C or less.

DETAILED DESCRIPTION OF THE INVENTION

It has been found that methods of cleaning dishes using liquid hand dishwashing detergent compositions, as described herein, and comprising a short-chain alkyl polyglucoside nonionic surfactant having an average alkyl carbon chain length of from 8 carbon atoms to 10 carbon atoms and a number average degree of polymerization of from 0.5 to 3.0, provide improved product dissolution of the detergent composition at low use temperatures, even when the overall surfactant level is increased, while also increasing suds mileage and grease cleaning at low usage temperatures.

Definitions

As used herein, articles such as "a" and "an" when used in a claim, are understood to mean one or more of what is claimed or described.
The term "comprising" as used herein means that steps and ingredients other than those specifically mentioned can be added. This term encompasses the terms "consisting of" and "consisting essentially of." The compositions of the present invention can comprise, consist of, and consist essentially of the essential elements and limitations of the invention described herein, as well as any of the additional or optional ingredients, components, steps, or limitations described herein.
The term "dishware" as used herein includes cookware and tableware made from, by non-limiting examples, ceramic, china, metal, glass, plastic (e.g., polyethylene, polypropylene, polystyrene, etc.) and wood.
The term "grease" or "greasy" as used herein means materials comprising at least in part (i.e., at least 0.5 wt% by weight of the grease) saturated and unsaturated fats and oils, preferably oils and fats derived from animal sources such as beef, pig and/or chicken.
The terms "include", "includes" and "including" are meant to be non-limiting.
The term "particulate soils" as used herein means inorganic and especially organic, solid soil particles, especially food particles, such as for non-limiting examples: finely divided elemental carbon, baked grease particle, and meat particles.
The term "sudsing profile" as used herein refers to the properties of a cleaning composition relating to suds character during the dishwashing process. The term "sudsing profile" of a cleaning composition includes suds volume generated upon dissolving and agitation, typically manual agitation, of the cleaning composition in the aqueous washing solution, and the retention of the suds during the dishwashing process. Preferably, hand dishwashing cleaning compositions characterized as having "good sudsing profile" tend to have high suds volume and/or sustained suds volume, particularly during a substantial portion of or for the entire manual dishwashing process. This is important as the consumer uses high suds as an indicator that sufficient cleaning composition has been dosed. Moreover, the consumer also uses the sustained suds volume as an indicator that sufficient active cleaning ingredients (e.g., surfactants) are present, even towards the end of the dishwashing process. The consumer usually renews the washing solution when the sudsing subsides. Thus, a low sudsing cleaning composition will tend to be replaced by the consumer more frequently than is necessary because of the low sudsing level.
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 as described and claimed herein.
In all embodiments of the present invention, all percentages are by weight of the total composition, as evident by the context, unless specifically stated otherwise. All ratios are weight ratios, unless specifically stated otherwise, and all measurements are made at 25°C, unless otherwise designated.

Method of Washing

The compositions of use in the present invention are used in methods of manually washing dishware. The method comprises the step of: contacting dishware with a liquid hand dishwashing detergent composition as described herein, and water, wherein the water has a temperature of 30 °C or less, preferably wherein the water has a temperature of from 20 °C to 30 °C.
The water present in usual households can typically have a hardness of up to 3.0 mmol/l CaCO₃ equivalence. As such, the method described herein is suitable for use when washing with water having a hardness of up to 3.0 mmol/l, preferably 0.3 mmol/l to 2.7 mmol/l, more preferably from 0.75 mmol/l to 2 mmol/l CaCO₃ equivalence. The methods described herein can also be used when washing with water having substantially lower hardness.
Suitable methods can include the step of delivering the liquid hand dishwashing detergent composition to a volume of the water to form a wash solution, prior to contacting the dishware with the liquid hand dishwashing detergent composition and the water by immersing the dishware in the wash solution.
The wash solution can comprise the liquid hand dishwashing detergent composition at a level of from 100 ppm to 10,000 ppm, preferably from 200 ppm to 5000 ppm, more preferably from 500 ppm to 2000 ppm.
Typically, from 0.5 ml to 50 ml, preferably from 1.0 ml to 25 ml, more preferably from 2.5 ml to 10 ml of the liquid hand dishwashing detergent composition is combined with 1.0 l to 15 l, preferably from 1.5 1 to 10 1, more preferably from 2.5 to 7.5 l of water to form the wash solution. The actual amount of detergent composition used will be based on the judgment of the user, and will typically depend upon factors such as the particular product formulation of the detergent composition, including the concentration of active ingredients in the detergent composition, the number of soiled dishes to be cleaned, the degree of soiling on the dishes, and the like.
The soiled dishware is immersed in the wash liquor obtained, before scrubbing the soiled surface of the dishware with a cloth, sponge, or similar cleaning implement. The cloth, sponge, or similar cleaning implement is typically contacted with the dishware for a period of time ranged from 1 to 10 seconds, although the actual time will vary with each application and user preferences. Scrubbing can sometimes also take place after a period of soaking, for instance, after up to about 30 minutes of soaking.
Alternatively, prior to contacting the dishware with the liquid hand dishwashing detergent composition and the water, the liquid hand dishwashing detergent composition and the water are combined on a device, preferably wherein the device is a brush, a sponge, a nonwoven material, or a woven material, more preferably wherein the device is a sponge. The liquid hand dishwashing detergent composition and water can be combined on or in the device at ratios of from 25:75 to 1:99, preferably 15:85 to 1:99, more preferably 10:90 to 1:99.
The cleaning device or implement, and consequently the liquid dishwashing composition and the water, is directly contacted to the surface of each of the soiled dishes, to remove the soiling. The cleaning device or implement is typically contacted with each dishware surface for a period of time range from 1 to 10 seconds, although the actual time of application will depend upon factors such as the degree of soiling of the dish. The contacting of said cleaning device or implement to the dish surface is preferably accompanied by concurrent scrubbing
The dishware can be subsequently rinsed. By "rinsing", it is meant herein contacting the dishware cleaned with the process according to the present invention with substantial quantities of water. By "substantial quantities", it is meant usually from 1.0 to 20 L, or under running water.

Cleaning Composition

The cleaning composition is a liquid hand dishwashing cleaning composition. The cleaning composition is preferably an aqueous cleaning composition. As such, the composition can comprise from 50% to 85%, preferably from 50% to 75%, by weight of the total composition of water.
Preferably, the pH of the composition is from about 6 to about 14, preferably from about 7 to about 12, or more preferably from about 7.5 to about 10, as measured as a 10% solution in distilled water at 20°C. The pH of the composition can be adjusted using pH modifying ingredients known in the art.
The composition of the present invention can be Newtonian or non-Newtonian, preferably Newtonian in the usage shear rate range of from 0.1 s^-1 to 100 s^-1. Preferably, the composition has a viscosity of from 10 mPa·s to 10,000 mPa·s, preferably from 100 mPa·s to 5,000 mPa·s, more preferably from 300 mPa·s to 2,000 mPa·s, or most preferably from 500 mPa·s to 1,500 mPa·s, alternatively combinations thereof. The viscosity is measured at 20°C with a Brookfield RT Viscometer using spindle 31 with the RPM of the viscometer adjusted to achieve a torque of between 40% and 60%.

Surfactant System

The cleaning composition can comprise from 5.0% to 50%, preferably from 8.0% to 45%, more preferably from 15% to 40%, by weight of the total composition of a surfactant system.

Anionic surfactant

The liquid hand dishwashing detergent composition comprises a surfactant system. The surfactant system preferably comprises an anionic surfactant. The surfactant system can comprise from 5.0% to 40%, preferably from 7.5% to 30%, more preferably from 10% to 25% by weight of the composition of the anionic surfactant.
The anionic surfactant preferably comprises alkyl sulfated anionic surfactant. The surfactant system can comprise the alkyl sulfated anionic surfactant at a level of at least 50%, preferably at least 70%, preferably at least 90% by weight of the anionic surfactant. The anionic surfactant can consist of the alkyl sulfated anionic surfactant.
The alkyl sulfated anionic surfactant is preferably an alkyl alkoxylated sulfate anionic surfactant, preferably wherein the alkyl alkoxylated sulfate anionic surfactant has an average degree of alkoxylation of less than 3.0, more preferably from 0.5 to 3.0, most preferably from 1.0 to 2.0.
The greasy cleaning efficacy can be further improved by formulating the alkyl sulfated anionic surfactant with little or no ethoxylation. As such, the alkyl sulfated anionic surfactant can have an average degree of alkoxylation of less than 0.5, preferably less than 0.1 and in such embodiments is more preferably free of any alkoxylation. If alkoxylation is present, the alkyl sulfate anionic surfactant is preferably ethoxylated.
The average degree of alkoxylation is the mol average degree of alkoxylation (i.e., mol average alkoxylation degree) of all the alkyl sulfate anionic surfactant. Hence, when calculating the mol average alkoxylation degree, the mols of non-alkoxylated sulfate anionic surfactant are included: Mol average alkoxylation degree = (x1 * alkoxylation degree of surfactant 1 + x2 * alkoxylation degree of surfactant 2 + ....)/(x1 + x2 + ....) wherein x1, x2, ... are the number of moles of each alkyl (or alkoxy) sulfate anionic surfactant of the mixture and alkoxylation degree is the number of alkoxy groups in each alkyl sulfate anionic surfactant.
For improved sudsing, the surfactant system comprises at least 40%, preferably from 60% to 90%, more preferably from 70 to 80% by weight of the surfactant system of the anionic surfactant.
The anionic surfactant comprises at least 50%, preferably at least 70%, more preferably at least 90% by weight of the anionic surfactant of alkyl sulfated anionic surfactant. Most preferably, the anionic surfactant consists of alkyl sulfated surfactant, most preferably primary alkyl sulfated anionic surfactant. As such, while the surfactant system may comprise small amounts of further anionic surfactant, including sulfonates such as HLAS, or sulfosuccinate anionic surfactants, the surfactant system preferably comprises no further anionic surfactant beyond the alkyl sulfated anionic surfactant.
The alkyl sulfated anionic surfactant can have an alkyl chain comprising an average of from 8 to 18 carbon atoms, preferably from 10 to 14 carbon atoms, more preferably from 12 to 13 carbon atoms.
The alkyl chain of the alkyl sulfated anionic surfactant preferably has a mol fraction of C12 and C13 chains of at least 50%, preferably at least 65%, more preferably at least 80%, most preferably at least 90%. Suds mileage is particularly improved, especially in the presence of greasy soils, when the C13/C12 mol ratio of the alkyl chain is at least 50/50, preferably from 60/40 to 80/20, most preferably from 60/40 to 70/30, while not compromising suds mileage in the presence of particulate soils.
The alkyl sulfated anionic surfactant can have an average degree of branching of at least 5.0%, preferably from 10% to 50%, more preferably from 15% to 40%. As such, the alkyl sulfated anionic surfactant can comprise a mixture of linear and branched alkyl sulfated anionic surfactant.
The alkyl chains of the alkyl sulphated anionic surfactant can be derived from natural or synthetic origins. The linear chains can be natural alkyl chains which are preferably derived from coconut oil, coconut oil being more sustainably derivable while having a preferred chain length. The linear alkyl chains can be blended with a highly branched alkyl chain so that less branched alkyl chains need to be added in order to arrive at the desired degree of branching.
The overall degree of branching (as well as how the branching is achieved) affects not just the sustainability of the sourcing material, but also impacts the amount of organic solvent required to physically stabilise the liquid hand dishwashing composition. The branching of the alkyl sulfated anionic surfactant also affects the viscosity as well as the viscosity upon dilution, avoiding viscosity thickening upon dilution and ensuring that the composition is readily dispersible in the water.
The level of branching in the branched alkyl sulfate or alkyl alkoxy sulfate used in the detergent composition is calculated on a molecular basis. Commercially available non-alkoxylated alkyl sulfate anionic surfactant blends that are sold as "branched" will typically comprise a blend of linear alkyl sulfate as well as branched alkyl sulphate molecules. Commercially available alkyl alkoxy sulfate anionic surfactant blends that are sold as "branched" will typically comprise a blend of linear alkyl sulfate, branched alkyl sulfate, as well as linear alkyl alkoxy sulfate and branched alkyl alkoxy sulfate molecules. The actual calculation of the degree of branching is done based on the starting alcohol (and alkoxylated alcohols for alkyl alkoxy sulfate blends), rather than on the final sulfated materials, as explained in the weight average degree of branching calculation below: Weight average degree of branching (%) = [(x1 * wt% branched alcohol 1 in alcohol 1 + x2 * wt% branched alcohol 2 in alcohol 2 + ....)/(x1 + x2 + ....)] * 100 wherein x1, x2, ... are the weight in grams of each alcohol in the total alcohol mixture of the alcohols which were used as starting material before (alkoxylation and) sulphation to produce the alkyl (alkoxy) sulfate anionic surfactant. In the weight average degree of branching calculation, the weight of the alkyl alcohol used to form the alkyl sulfate anionic surfactant which is not branched is included.
The weight average degree of branching and the distribution of branching can typically be obtained from the technical data sheet for the surfactant or constituent alkyl alcohol. Alternatively, the branching can also be determined through analytical methods known in the art, including capillary gas chromatography with flame ionisation detection on medium polar capillary column, using hexane as the solvent. The weight average degree of branching and the distribution of branching is based on the starting alcohol used to produce the alkyl sulfated anionic surfactant.
The branched alkyl sulfated anionic surfactant can comprise C2-branched alkyl sulfated anionic surfactant and optionally non-C2-branched alkyl sulfated anionic surfactant. The branched alkyl sulfated anionic surfactant can comprise at least 90%, preferably at least 95%, more preferably at least 98% by weight of the branched alkyl sulfated anionic surfactant of C2-branched alkyl sulfated anionic surfactant and at most 10%, preferably at most 5%, most preferably at most 2% by weight of the branched alkyl sulfated anionic surfactant of non-C2 branched alkyl sulfate anionic surfactant.
C2-branched means the alkyl branching is a single alkyl branching on the alkyl chain of the alkyl sulfated anionic surfactant and is positioned on the C2 position, as measured counting carbon atoms from the sulfate group for non-alkoxylated alkyl sulfate anionic surfactants, or counting from the alkoxy-group furthest from the sulfate group for alkoxylated alkyl sulfate anionic surfactants.
Non-C2 branching means the alkyl chain comprises branching at multiple carbon positions along the alkyl chain backbone, or a single branching group present on a branching position on the alkyl chain other than the C2 position.
The non-C2 branched alkyl sulfated anionic surfactant can comprise less than 30%, preferably less than 20%, more preferably less than 10% by weight of the non-C2 branched alkyl sulfated anionic surfactant of C1-branched alkyl sulfated anionic surfactant, most preferably the non-C2 branched alkyl sulfated anionic surfactant is free of C1-branched alkyl sulfated anionic surfactant.
The non-C2 branched alkyl sulfated anionic surfactant can comprise at least 50%, preferably from 60 to 90%, more preferably from 70 to 80% by weight of the non-C2 branched alkyl sulfated anionic surfactant of isomers comprising a single branching at a branching position greater than the 2-position. That is, more than 2 carbons atoms away from the hydrophilic headgroup, as defined above. The non-C2 branched alkyl sulfated anionic surfactant can comprise from 5% to 30%, preferably from 7% to 20%, more preferably from 10% to 15% by weight of the non-C2 branched alkyl sulfated anionic surfactant of multi-branched isomers. The non-C2 branched alkyl sulfated anionic surfactant can comprise from 5% to 30%, preferably from 7% to 20%, more preferably from 10% to 15% by weight of non-C2 branched alkyl sulfated anionic surfactant of cyclic isomers. If present, the acyclic branching groups can be selected from C1 to C5 alkyl groups, and mixtures thereof.
It has been found that formulating the compositions using alkyl sulfated anionic surfactants having the aforementioned branching distribution and reduced to nil ethoxylation results in reduced viscosensitivity to variations in temperature and, as such, a more consistent dosage experience, compared to compositions comprising alkyl sulfated anionic surfactants with a comparative branching distribution. Moreover, the composition maintains a Newtonian viscosity profile for a broader shear rate range, which means less dosage variation and a more consistent user experience, regardless of how hard the container is squeezed.
Suitable counterions for the anionic surfactant include alkali metal cation earth alkali metal cation, alkanolammonium or ammonium or substituted ammonium, but preferably sodium.
Suitable examples of commercially available alkyl sulfated anionic surfactants include, those derived from alcohols sold under the Neodol^® brand-name by Shell, or the Lial^®, Isalchem^®, and Safol^® brand-names by Sasol, or some of the natural alcohols produced by The Procter & Gamble Chemicals company. The alcohols can be blended in order to achieve the desired average alkyl chain, average degree of branching and type of branching distribution according to the invention. Considering the targeted branched alkyl sulfated anionic surfactant according to the invention has a high dominance of C2 branched alkyl sulfated anionic surfactant content, preferably the alkyl sulfated anionic surfactant comprises an OXO derived alkyl sulfated anionic surfactant, such as commercially available under the lial and isalchem brandname from the Sasol company, and Neodol from the Shell company, OXO derived alkyl sulfated anionic surfactants comprising branched alkyl sulfated anionic surfactant consisting essentially of C2 branched alkyl sulfate anionic surfactant. OXO alcohols are alcohols that are prepared by adding carbon monoxide (CO) and hydrogen (usually combined together as synthesis gas) to an olefin to obtain an aldehyde using the hydroformylation reaction and then hydrogenating the aldehyde to obtain the alcohol. More preferably the alkyl sulfated anionic surfactant comprises from 60% to 85%, preferably from 75% to 85% by weight of the alkyl sulfate anionic surfactant of OXO-derived alkyl sulfated anionic surfactant, wherein OXO alcohols are alcohols that are prepared by adding carbon monoxide (CO) and hydrogen to an olefin to obtain an aldehyde using the hydroformylation reaction and then hydrogenating the aldehyde to obtain the alcohol. Alternative processes yielding alkyl sulfated anionic surfactants comprising branched alkyl sulfated anionic surfactant with high dominance of C2 branched alkyl sulfated anionic surfactant are also considered suitable for the invention. An example of such an alternative process is described in US applications 63/035125 and 63/035131 . As such the alkyl sulfated anionic surfactant then comprises at least 30%, preferably from 40% to 95%, more preferably from 50% to 85% by weight of alkyl sulfated anionic surfactant of this alternative process derived alkyl sulfate anionic surfactant, or of a mixture of OXO derived and this alternative process derived alkyl sulfate anionic surfactant.
If ethoxylated alkyl sulfate is present, without wishing to be bound by theory, through tight control of processing conditions and feedstock material compositions, both during alkoxylation especially ethoxylation and sulfation steps, the amount of 1,4-dioxane by-product within alkoxylated especially ethoxylated alkyl sulfates can be reduced. Based on recent advances in technology, a further reduction of 1,4-dioxane by-product can be achieved by subsequent stripping, distillation, evaporation, centrifugation, microwave irradiation, molecular sieving or catalytic or enzymatic degradation steps. Processes to control 1,4-dioxane content within alkoxylated/ethoxylated alkyl sulfates have been described extensively in the art. Alternatively 1,4-dioxane level control within detergent formulations has also been described in the art through addition of 1,4-dioxane inhibitors to 1,4-dioxane comprising formulations, such as 5,6-dihydro-3-(4-morpholinyl)-1-[4-(2-oxo-1-piperidinyl)-phenyl]-2-(1-H)-pyridone, 3-α-hydroxy-7-oxo stereoisomer-mixtures of cholinic acid, 3-(N- methyl amino)-L-alanine, and mixtures thereof.

Short-chain alkyl polyglucoside nonionic surfactant

Alkyl polyglucoside nonionic surfactants are typically more sudsing than other nonionic surfactants such as alkyl ethoxlated alcohols, especially in the presence of particulate soils. A combination of alkylpolyglucoside and alkyl sulfate anionic surfactant has been found to improve polymerized grease removal, suds mileage performance, reduced viscosity variation with changes in the surfactant and/or the surfactant system, and a more sustained Newtonian rheology across a wider surfactant active level range.
The liquid hand dishwashing detergent composition comprises a surfactant system, wherein the surfactant system comprises: short-chain alkyl polyglucoside nonionic surfactant, wherein the short-chain alkyl polyglucoside nonionic surfactant has an average alkyl carbon chain length of from 8 carbon atoms to 10 carbon atoms and a number average degree of polymerization of from 0.5 to 3.0. The short-chain alkyl polyglucoside surfactant can have a number average degree of polymerization of from 0.1 to 3.0, preferably from 1.0 to 2.0, more preferably from 1.2 to 1.6. The weight ratio of C8 alkyl polyglucoside to C10 alkyl polyglucoside is preferably from 40:60 to 60:40. At least 90%, preferably at least 95%, more preferably at least 98%, by weight of the short-chain alkyl polyglucoside surfactant can have a carbon chain length of 8 to 10 carbon atoms.
The surfactant system can comprise from 0.1% to 8.0%, preferably from 0.5% to 4.0%, more preferably from 1.0% to 3.0% by weight of the composition of the short-chain alkyl polyglucoside nonionic surfactant. The anionic surfactant and the short-chain alkyl polyglucoside surfactant can be present at a weight ratio of from greater than 0.5:1 to 25: 1, preferably from 1:1 to 20:1, more preferably from 5:1 to 15:1.
Alkyl polyglucoside nonionic surfactants are typically more sudsing than other nonionic surfactants such as alkyl ethoxlated alcohols, especially in the presence of particulate soils.
Short-chain alkyl polyglucoside nonionic surfactants have also been found to improve cold water product dissolution and grease cleaning performance.
Glucopon^® 215UP is a preferred C8-C10 alkyl polyglucoside surfactant. Other suitable short-chain alkyl polyglucosides include PLANTACARE^® 810 UP, Supplied by BASF.

Co-surfactant

In order to improve surfactant packing after dilution and hence improve suds mileage, the surfactant system can comprise a co-surfactant in addition to the anionic surfactant.
The co-surfactant can be selected from the group consisting of an amphoteric surfactant, a zwitterionic surfactant, and mixtures thereof.
The weight ratio of anionic surfactant to the co-surfactant can be from 2.0:1 to 8.0:1, preferably from 2.0:1 to 5.0:1, more preferably from 2.5:1 to 4.0:1, in order to provide improved grease cleaning, sudsing and viscosity build.
The surfactant system can comprise from 0.1% to 20%, preferably from 0.5% to 15%, more preferably from 2% to 10% by weight of the cleaning composition of the co-surfactant. The surfactant system of the cleaning composition of the present invention can comprise from 10% to 40%, preferably from 15% to 35%, more preferably from 20% to 30%, by weight of the surfactant system of the co-surfactant.
The co-surfactant can be an amphoteric surfactant, such as an amine oxide surfactant. The amine oxide surfactant can be linear or branched, though linear are preferred. Suitable linear amine oxides are typically water-soluble, and characterized by the formula R1 - N(R2)(R3) O wherein R1 is a C8-18 alkyl, and the R2 and R3 moieties are selected from the group consisting of C1-3 alkyl groups, C1-3 hydroxyalkyl groups, and mixtures thereof. For instance, R2 and R3 can be selected from the group consisting of: methyl, ethyl, propyl, isopropyl, 2-hydroxethyl, 2-hydroxypropyl and 3-hydroxypropyl, and mixtures thereof, though methyl is preferred for one or both of R2 and R3. The linear amine oxide surfactants in particular may include linear C10-C18 alkyl dimethyl amine oxides and linear C8-C12 alkoxy ethyl dihydroxy ethyl amine oxides.
Preferably, the amine oxide surfactant is selected from the group consisting of: alkyl dimethyl amine oxide, alkyl amido propyl dimethyl amine oxide, and mixtures thereof. Alkyl dimethyl amine oxides are preferred, such as C8-18 alkyl dimethyl amine oxides, or C10-16 alkyl dimethyl amine oxides (such as coco dimethyl amine oxide). Suitable alkyl dimethyl amine oxides include C10 alkyl dimethyl amine oxide surfactant, C10-12 alkyl dimethyl amine oxide surfactant, C12-C14 alkyl dimethyl amine oxide surfactant, and mixtures thereof. C12-C14 alkyl dimethyl amine oxide are particularly preferred. Preferably, the alkyl chain of the alkyl dimethyl amine oxide is a linear alkyl chain, preferably a C12-C14 alkyl chain, more preferably a C12-C14 alkyl chain derived from coconut oil or palm kernel oil.
Alternative suitable amine oxide surfactants include mid-branched amine oxide surfactants. As used herein, "mid-branched" means that the amine oxide has one alkyl moiety having n1 carbon atoms with one alkyl branch on the alkyl moiety having n2 carbon atoms. The alkyl branch is located on the α carbon from the nitrogen on the alkyl moiety. This type of branching for the amine oxide is also known in the art as an internal amine oxide. The total sum of n1 and n2 can be from 10 to 24 carbon atoms, preferably from 12 to 20, and more preferably from 10 to 16. The number of carbon atoms for the one alkyl moiety (n1) is preferably the same or similar to the number of carbon atoms as the one alkyl branch (n2) such that the one alkyl moiety and the one alkyl branch are symmetric. As used herein "symmetric" means that | n1 - n2 | is less than or equal to 5, preferably 4, most preferably from 0 to 4 carbon atoms in at least 50 wt%, more preferably at least 75 wt% to 100 wt% of the mid-branched amine oxides for use herein. The amine oxide further comprises two moieties, independently selected from a C1-3 alkyl, a C1-3 hydroxyalkyl group, or a polyethylene oxide group containing an average of from 1 to 3 ethylene oxide groups. Preferably, the two moieties are selected from a C1-3 alkyl, more preferably both are selected as C1 alkyl.
Alternatively, the amine oxide surfactant can be a mixture of amine oxides comprising a mixture of low-cut amine oxide and mid-cut amine oxide. The amine oxide of the composition of the invention can then comprises:

a) from 10% to 45% by weight of the amine oxide of low-cut amine oxide of formula R1R2R3AO wherein R1 and R2 are independently selected from hydrogen, C1-C4 alkyls or mixtures thereof, and R3 is selected from C10 alkyls and mixtures thereof;
and
b) from 55% to 90% by weight of the amine oxide of mid-cut amine oxide of formula R4R5R6AO wherein R4 and R5 are independently selected from hydrogen, C1-C4 alkyls or mixtures thereof, and R6 is selected from C12-C16 alkyls or mixtures thereof

In a preferred low-cut amine oxide for use herein R3 is n-decyl, with preferably both R1 and R2 being methyl. In the mid-cut amine oxide of formula R4R5R6AO, R4 and R5 are preferably both methyl.
Preferably, the amine oxide comprises less than 5%, more preferably less than 3%, by weight of the amine oxide of an amine oxide of formula R7R8R9AO wherein R7 and R8 are selected from hydrogen, C1-C4 alkyls and mixtures thereof and wherein R9 is selected from C8 alkyls and mixtures thereof. Limiting the amount of amine oxides of formula R7R8R9AO improves both physical stability and suds mileage.
The co-surfactant can be zwitterionic surfactants such as a betaine surfactant. Such betaine surfactants include alkyl betaines, alkylamidobetaine, amidazoliniumbetaine, sulphobetaine (INCI Sultaines) as well as the Phosphobetaine, and preferably meets formula (I):

R¹-[CO-X(CH₂)_n]_x-N⁺(R²)(R₃)-(CH₂)_m-[CH(OH)-CH₂]_y-Y^-

wherein in formula (I),

R1 is selected from the group consisting of: a saturated or unsaturated C6-22 alkyl residue, preferably C8-18 alkyl residue, more preferably a saturated C10-16 alkyl residue, most preferably a saturated C12-14 alkyl residue;
X is selected from the group consisting of: NH, NR4 wherein R4 is a C1-4 alkyl residue, O, and S,
n is an integer from 1 to 10, preferably 2 to 5, more preferably 3,
x is 0 or 1, preferably 1,
R2 and R3 are independently selected from the group consisting of: a C1-4 alkyl residue, hydroxy substituted such as a hydroxyethyl, and mixtures thereof, preferably both R2 and R3 are methyl,
m is an integer from 1 to 4, preferably 1, 2 or 3,
y is 0 or 1, and
Y is selected from the group consisting of: COO, SO3, OPO(OR5)O or P(O)(OR5)O, wherein R5 is H or a C1-4 alkyl residue.

Preferred betaines are the alkyl betaines of formula (IIa), the alkyl amido propyl betaine of formula (IIb), the sulphobetaines of formula (IIc) and the amido sulphobetaine of formula (IId):

R¹-N⁺(CH₃)₂-CH₂COO^- (IIa)

R¹-CO-NH-(CH₂)₃-N⁺(CH₃)₂-CH₂COO^- (IIb)

R¹-N⁺(CH₃)₂-CH₂CH(OH)CH₂SO₃ ^- (IIc)

R¹-CO-NH-(CH₂)₃-N⁺(CH₃)₂-CH₂CH(OH)CH₂SO₃ ^- (IId)

in which R1 has the same meaning as in formula (I). Particularly preferred are the carbobetaines [i.e. wherein Y^-=COO- in formula (I)] of formulae (IIa) and (IIb), more preferred are the alkylamidobetaine of formula (IIb).
Suitable betaines can be selected from the group consisting or [designated in accordance with INCI]: capryl/capramidopropyl betaine, cetyl betaine, cetyl amidopropyl betaine, cocamidoethyl betaine, cocamidopropyl betaine, cocobetaines, decyl betaine, decyl amidopropyl betaine, hydrogenated tallow betaine / amidopropyl betaine, isostearamidopropyl betaine, lauramidopropyl betaine, lauryl betaine, myristyl amidopropyl betaine, myristyl betaine, oleamidopropyl betaine, oleyl betaine, palmamidopropyl betaine, palmitamidopropyl betaine, palm-kernelamidopropyl betaine, stearamidopropyl betaine, stearyl betaine, tallowamidopropyl betaine, tallow betaine, undecylenamidopropyl betaine, undecyl betaine, and mixtures thereof. Preferred betaines are selected from the group consisting of: cocamidopropyl betaine, cocobetaines, lauramidopropyl betaine, lauryl betaine, myristyl amidopropyl betaine, myristyl betaine, and mixtures thereof. Cocamidopropyl betaine is particularly preferred.

Further nonionic surfactant

The composition can comprise a further nonionic surfactant. The further nonionic surfactant is preferably selected from the group consisting of: alkoxylated alkyl alcohol, alkyl polyglucoside wherein the alkyl polyglucoside nonionic surfactant has an average alkyl carbon chain length of greater than 10 carbon atoms, and mixtures thereof, more preferably the nonionic surfactant is selected from alkoxylated alkyl alcohols, most preferably ethoxylated alkyl alcohols.
The surfactant system can comprise the nonionic surfactant at a level of from 1% to 25%, preferably from 1.25% to 15%, more preferably from 1.5% to 10%, by weight of the surfactant system.
Suitable alkoxylated non-ionic surfactants can be linear or branched, primary or secondary alkyl alkoxylated non-ionic surfactants. The alkoxylated nonionic surfactant can comprise on average of from 8 to 18, preferably from 9 to 15, more preferably from 10 to 14 carbon atoms in its alkyl chain.
Alkyl ethoxylated non-ionic surfactant are preferred. Suitable alkyl ethoxylated non-ionic surfactants can comprise an average of from 5 to 12, preferably from 6 to 10, more preferably from 7 to 8, units of ethylene oxide per mole of alcohol. Such alkyl ethoxylated nonionic surfactants can be derived from synthetic alcohols, such as OXO-alcohols and Fisher Tropsh alcohols, or from naturally derived alcohols, or from mixtures thereof. Suitable examples of commercially available alkyl ethoxylate nonionic surfactants include, those derived from synthetic alcohols sold under the Neodol^® brand-name by Shell, or the Lial^®, Isalchem^®, and Safol^® brand-names by Sasol, or some of the natural alcohols produced by The Procter & Gamble Chemicals company.
The surfactant system does not comprise mid to long chain further alkyl polyglucosides which have a weight average alkyl carbon chain length of greater than 10 carbon atoms. Hence, the alkyl polyglucoside consists of the short chain alkyl polyglucoside.
The further alkyl polyglucoside surfactant can be selected from C6-C18 alkyl polyglucoside surfactant. The further alkyl polyglucoside surfactant can have a number average degree of polymerization of from 0.1 to 3.0, preferably from 1.0 to 2.0, more preferably from 1.2 to 1.6.
As such, the alkyl polyglucoside surfactant can comprise a blend of short chain alkyl polyglucoside surfactant having an alkyl chain comprising 10 carbon atoms or less, and mid to long chain alkyl polyglucoside surfactant having an alkyl chain comprising greater than 10 carbon atoms to 18 carbon atoms, preferably from 12 to 14 carbon atoms.
Short chain alkyl polyglucoside surfactants have a monomodal chain length distribution having a weight average chain length of between C8-C10. Mid to long chain alkyl polyglucoside surfactants have a monomodal chain length distribution with a weight average chain length of between C10-C18, typically of between C12 to C14. In contrast, C8 to C18 alkyl polyglucoside surfactants typically have a monomodal distribution of alkyl chains between C8 and C18, as with C8 to C16 and the like. As such, a combination of short chain alkyl polyglucoside surfactants with mid to long chain or mid chain alkyl polyglucoside surfactants have a broader distribution of chain lengths, or even a bimodal distribution, than non-blended C8 to C18 alkyl polyglucoside surfactants. When present, the weight ratio of short chain alkyl polyglucoside surfactant to mid to long chain alkyl polyglucoside surfactant can be from 1:1 to 10:1, preferably from 1.5:1 to 5:1, more preferably from 2:1 to 4:1. It has been found that a blend of such short chain alkyl polyglucoside surfactant and long chain alkyl polyglucoside surfactant results in faster dissolution of the detergent solution in water and improved initial sudsing, in combination with improved suds stability.
C12-C16 alkyl polyglucosides are commercially available from several suppliers, including PLANTACARE^® 1200 UP, supplied by BASF.

Organic Solvent:

The composition can comprise from 0.1% to 10%, or preferably from 0.5% to 10%, or more preferably from 1% to 10% by weight of the total composition of an organic solvent. Suitable organic solvents include organic solvents selected from the group consisting of: alcohols, glycols, glycol ethers, and mixtures thereof, preferably alcohols, glycols, and mixtures thereof. Ethanol is the preferred alcohol. Polyalkyleneglycols, especially polypropyleneglycol (PPG), are the preferred glycol. The polypropyleneglycol can have a molecular weight of from 400 to 3000, preferably from 600 to 1500, more preferably from 700 to 1300. The polypropyleneglycol is preferably poly-1,2-propyleneglycol.

Further ingredients:

The composition can comprise further ingredients such as those selected from: amphiphilic alkoxylated polyalkyleneimines, cyclic polyamines, triblock copolymers, salts, hydrotropes, organic solvents, other adjunct ingredients such as those described herein, and mixtures thereof.

Amphiphilic alkoxylated polyalkyleneimine:

The composition of the present invention may further comprise from 0.05% to 2%, preferably from 0.07% to 1% by weight of the total composition of an amphiphilic polymer. Suitable amphiphilic polymers can be selected from the group consisting of: amphiphilic alkoxylated polyalkyleneimine and mixtures thereof. The amphiphilic alkoxylated polyalkyleneimine polymer has been found to reduce gel formation on the hard surfaces to be cleaned when the liquid composition is added directly to a cleaning implement (such as a sponge) before cleaning and consequently brought in contact with heavily greased surfaces, especially when the cleaning implement comprises a low amount to nil water such as when light pre-wetted sponges are used.
A preferred amphiphilic alkoxylated polyethyleneimine polymer has the general structure of formula (I): wherein the polyethyleneimine backbone has a weight average molecular weight of 600, n of formula (I) has an average of 10, m of formula (I) has an average of 7 and R of formula (I) is selected from hydrogen, a C₁-C₄ alkyl and mixtures thereof, preferably hydrogen. The degree of permanent quaternization of formula (I) may be from 0% to 22% of the polyethyleneimine backbone nitrogen atoms. The molecular weight of this amphiphilic alkoxylated polyethyleneimine polymer preferably is between 10,000 and 15,000 Da.
More preferably, the amphiphilic alkoxylated polyethyleneimine polymer has the general structure of formula (I) but wherein the polyethyleneimine backbone has a weight average molecular weight of 600 Da, n of Formula (I) has an average of 24, m of Formula (I) has an average of 16 and R of Formula (I) is selected from hydrogen, a C₁-C₄ alkyl and mixtures thereof, preferably hydrogen. The degree of permanent quaternization of Formula (I) may be from 0% to 22% of the polyethyleneimine backbone nitrogen atoms and is preferably 0%. The molecular weight of this amphiphilic alkoxylated polyethyleneimine polymer preferably is between 25,000 and 30,000, most preferably 28,000 Da.
The amphiphilic alkoxylated polyethyleneimine polymers can be made by the methods described in more detail in PCT Publication No. WO 2007/135645 .

Cyclic Polyamine

The composition can comprise a cyclic polyamine having amine functionalities that helps cleaning. The composition of the invention preferably comprises from 0.1% to 3%, more preferably from 0.2% to 2%, and especially from 0.5% to 1%, by weight of the composition, of the cyclic polyamine.
The cyclic polyamine has at least two primary amine functionalities. The primary amines can be in any position in the cyclic amine but it has been found that in terms of grease cleaning, better performance is obtained when the primary amines are in positions 1,3. It has also been found that cyclic amines in which one of the substituents is -CH3 and the rest are H provided for improved grease cleaning performance.
Accordingly, the most preferred cyclic polyamine for use with the cleaning composition of the present invention are cyclic polyamine selected from the group consisting of: 2-methylcyclohexane-1,3-diamine, 4-methylcyclohexane-1,3-diamine and mixtures thereof. These specific cyclic polyamines work to improve suds and grease cleaning profile through-out the dishwashing process when formulated together with the surfactant system of the composition of the present invention.
Suitable cyclic polyamines can be supplied by BASF, under the Baxxodur tradename, with Baxxodur ECX-210 being particularly preferred.
A combination of the cyclic polyamine and magnesium sulphate is particularly preferred. As such, the composition can further comprise magnesium sulphate at a level of from 0.001 % to 2.0 %, preferably from 0.005 % to 1.0 %, more preferably from 0.01 % to 0.5 % by weight of the composition.
The composition of the present invention may further comprise at least one active selected from the group consisting of: salt, hydrotrope, and mixtures thereof.

Salt:

The composition of the present invention may comprise from 0.05% to 2%, preferably from 0.1% to 1.5%, or more preferably from 0.5% to 1%, by weight of the total composition of a salt, preferably a monovalent or divalent inorganic salt, or a mixture thereof, more preferably selected from: sodium chloride, sodium sulfate, and mixtures thereof. Sodium chloride is most preferred.

Hydrotrope:

The composition of the present invention may comprise from 0.1% to 10%, or preferably from 0.5% to 10%, or more preferably from 1% to 10% by weight of the total composition of a hydrotrope or a mixture thereof, preferably sodium cumene sulfonate.

Adjunct Ingredients

The cleaning composition may optionally comprise a number of other adjunct ingredients such as builders (preferably citrate), chelants, conditioning polymers, other cleaning polymers, surface modifying polymers, structurants, emollients, humectants, skin rejuvenating actives, enzymes, carboxylic acids, scrubbing particles, perfumes, malodor control agents, pigments, dyes, opacifiers, pearlescent particles, inorganic cations such as alkaline earth metals such as Ca/Mg-ions, antibacterial agents, preservatives, viscosity adjusters (e.g., salt such as NaCl, and other mono-, di- and trivalent salts) and pH adjusters and buffering means (e.g. carboxylic acids such as citric acid, HCl, NaOH, KOH, alkanolamines, carbonates such as sodium carbonates, bicarbonates, sesquicarbonates, and alike).

Packaged product

The hand dishwashing detergent composition can be packaged in a container, typically plastic containers. Suitable containers comprise an orifice. Suitable containers include traditional upright dosing containers, where the orifice is at the top of the container, and inverted/bottom dosing containers, where the orifice is at the bottom of the container. For inverted/bottom dosing containers, the orifice may be capped and/or the orifice may comprise a slit valve, such as described in US Patent No. 10,611,531 . Typically, the container comprises a cap, with the orifice typically comprised on the cap. The cap can comprise a spout, with the orifice at the exit of the spout. The spout can have a length of from 0.5 mm to 10 mm.
The orifice can have an open cross-sectional surface area at the exit of from 3 mm2 to 20 mm2, preferably from 3.8 mm2 to 12 mm2, more preferably from 5 mm2 to 10 mm2, wherein the container further comprises the composition according to the invention. The cross-sectional surface area is measured perpendicular to the liquid exit from the container (that is, perpendicular to the liquid flow during dispensing).
The container can typically comprise from 200 ml to 5,000 ml, preferably from 350 ml to 2000 ml, more preferably from 400 ml to 1,000 ml of the liquid hand dishwashing detergent composition.

TEST METHODS

pH

The pH is measured as a 10% solution in demineralized water at 20 °C, unless specified otherwise.

Viscosity measurement

The viscosity is measured at 20°C with a Brookfield RT Viscometer using spindle 31 with the RPM of the viscometer adjusted to achieve a torque of between 40% and 60%.

Composition dissolution time:

4 litres of demineralized water at 20°C is added to a 5 liter glass beaker (diameter 18cm, height 25.5cm). A 4-bladed mixer (supplied by Labortechnik, diameter 10cm), connected to an overhead motor, is placed centrally with the blades inclined at 45°, and the blade axis positioned 5cm under the water level. A conductivity probe with built in auto data saving memory (supplied by WTW, Type TetraCon 325) is placed 4 cm under the water level about 1 cm from the beaker wall. 5 ml of test product is carefully added using a pipette to the centre of the bottom of the glass beaker straight, immediately after which the blade stirring is started at 90 RPM. The solution conductivity is measured continuously and plotted as a function of time. The test stops once a constant solution conductivity has been observed for 20 seconds and no undissolved test product is visually observed anymore. The dissolution time (in seconds) is recorded as the time taken to reach 70% of the constant solution conductivity value. The average of 3 replicates is reported.

Suds Mileage in presence of particulate soil

The objective of the Suds Mileage Test is to compare the evolution over time of suds volume generated for different test formulations at specified water hardness, solution temperatures and formulation concentrations, while under the influence of periodic soil injections. Data are compared and expressed versus a reference composition as a suds mileage index (reference composition has suds mileage index of 100). The steps of the method are as follows:

1. A defined amount of a test composition, depending on the targeted composition concentration (here : 0.12 wt%), is dispensed through a plastic pipette at a flow rate of 0.67 mL/ sec at a height of 37 cm above the bottom surface of a sink (dimension: 300 mm diameter and 288 mm height) into a water stream (here : water hardness: 1.25 mmol CaCO₃ (7dH), water temperature : 25°C) that is filling up the sink to 4 L with a constant pressure of 4 bar.
2. An initial suds volume generated (measured as average foam height X sink surface area and expressed in cm³) is recorded immediately after end of filling.
3. A fixed amount (6 mL) of the soil with defined composition as below is immediately injected into the middle of the sink.
4. The resultant solution is mixed with a metal blade (10 cm x 5 cm) positioned in the middle of the sink at the air liquid interface under an angle of 45 degrees rotating at 85 RPM for 20 revolutions.
5. Another measurement of the total suds volume is recorded immediately after end of blade rotation.
6. Steps 3-5 are repeated until the measured total suds volume reaches a minimum level of 400 cm³. The amount of added soil that is needed to get to the 400 cm³ level is considered as the suds mileage for the test composition.
7. Each test composition is tested 4 times per testing condition (i.e., water temperature, composition concentration, water hardness, soil type).
8. The average suds mileage is calculated as the average of the 4 replicates for each sample for a defined test condition.
9. Calculate a Suds Mileage Index by comparing the average mileage of a test composition sample versus a reference composition sample. The calculation is as follows:

Suds Mileage Index = \frac{\begin{matrix} Average number of soil additions \\ of test composition \end{matrix}}{\begin{matrix} Average number of soil additions \\ of reference composition \end{matrix}} \times 100

The particulate soil compositions used in the test were produced through standard mixing of the components described in Table 1.

Table 1: Particulate Soil

Ingredient	Weight %
Zwan Flemish Carbonades	22.67
Beaten Eggs	4.78
Smash Instant Mash Potato	9.26
McDougall's Sponge Mix	3.30
Milk UHT Full Cream	22.22
Bisto Gravy Granules	1.30
Mazola^® Pure Corn Oil	9.29
Demineralized water	26.32
Sodium Benzoate	0.42
Potassium Sorbate	0.42

Grease cleaning rate after soaking:

The following test is carried out under lab conditions with a room temperature of 20°C and 40% relative humidity.
Enamel tiles (white enamel tile, of size 25 cm by 7 cm, 0.2 cm thick, supplied by Emaillerie Belge, Rue Saint-Denis 122, 1190 Forest, BE) are first pretreated using the following procedure:
The tiles are first cleaned using Dreft Original (Belgium) dishwashing liquid detergent and water and then using ethanol. The tiles are then soaked overnight in a solution of 50% Mr Proper all-purpose cleaner in water. The cleaned tiles are then bakes at 140 °C for 2 hours in an oven before washing again using Dreft Original (Belgium) dishwashing liquid detergent and water.
75% of a blend of vegetable-based cooking oils (by weight, 1/3 corn oil, 1/3 sunflower oil and 1/3 peanut oil, sourced from Vandemoortele Belgium), and 24.3% of albumin powder (from white grade II chicken eggs, sourced from Sigma Chemicals), and 0.7% of Oil Red Dye (Lumogen F Rot 305, sourced from BASF) are homogeneously mixed together at room temperature to form the test-soil composition.
The test-soil is homogeneously deposited over the full surface of the cleaned enamel tile using a synthetic foam paint roller (7 cm length and 4 cm diameter) until an amount of 0.65g +/-0.05g of test-soil has been deposited onto the tile. The tile is then baked for 3 hours at 140 °C in an oven, and then conditioned for 24 hours at 25 °C and 70% relative humidity (for instance, using a Climatic Control Cabinet-Type Pharma 600 from Weisstechnik).

The tiles are pre-soaked using the following procedure:

A 2.0% by weight solution of the test composition in water of hardness 2.67 mmol/l CaCO₃ equivalence (15 dH) at 23°C is prepared. The resulting pre-soaking solution is poured into a plastic bucket of sufficient size to immerse the tiles (f.e. 28 cm diameter). The tiles are immersed for 2 minutes in the pre-soaking solution, followed immediately by placing on the tracks of a straight-line sheen machine tester (Wet Abrasion Scrub Tester Ref. 903PG/SA/B - supplied by Sheen Instruments Limited).
New white standardized synthetic sponges (supplied by CFT, Model ref. 903PG 45 x 90mm, Intrastat code: 39129020) are used in this test and placed in the sponge holder of the sheen machine tester.
10 ml of a 7.5% test composition solution in water of hardness 2.67 mmol/l CaCO₃ equivalence (15 dH) at 20°C is poured onto each sponge (using a syringe). Four sponges, each comprising the same test product, were placed in each sponge holder of the sheen machine. A weight of 200 g was placed on top of the sponges and the sheen machine was set at a moving speed of 20 cycles/minute for the sponge, with each cycle having a stroke length of 29.5 cm in each direction.
The sheen tester is placed in a closed box with a standardized white light source. Any suitable standardized white light source can be used so long as it provides a uniform distribution over the tiles of white light (such as D50 light). Every two strokes, a picture is taken using a digital camera. In the present method, a Nikon D5300 camera, with a 35mm f1.8 lens, manually set to f5.6, ISO200 and shutter speed 1/125s is used.
The test is stopped when the tiles are fully cleaned or after 100 strokes. For each product a minimum of 8 replicates are generated. All of the images are then transferred to the Matlab^® software, where they are converted from RBG to L,a,b scale, before calculating Stain Removal Index (versus original soiled tile) based on the L,a,b values. The stain removal index (SRI) data then are analyzed with a statistical program and fitted following a sigmoid curve (fit logistic 3P) which results in mathematical equation containing 3 parameters (a = Growth rate, b = Inflection point, c = Asymptote) that describe the whole cleaning process. Delta SRI = c / (1 + Exp( -a * (number of strokes - b))).
The growth rate parameter (a) is used as a measure for the "cleaning rate" of the product. The "cleaning rate" is compared between products by indexing this value versus a reference product.

Viscosity upon dilution:

Solutions at a weight% concentration of 100%, 90%, 80% and 70% of the composition in demineralized water at 20°C are prepared. The viscosities of the solutions are then measured following the viscosity test method described herein. The compositions are classified based on whether the viscosity peaks (thickening), is maintained, or continuously declines upon dilution of the composition within the tested concentration range, prior to reducing during subsequent further dilution.

EXAMPLES

The following compositions were prepared by simple mixing and evaluated for dissolution speed, suds mileage in presence of particulate soils, and grease emulsification and grease removal, using the methods described herein.

Example 1 comprised a short chain (C8-C10) alkyl polyglucoside and hence was of use in the present invention. In contrast, example A comprised a C12-C14 alkyl polyglucoside and hence is comparative. Example B did not comprise any alkyl polyglucoside and hence is also comparative.

Table 1: Inventive and comparative liquid hand dishwashing detergent compositions

wt% (100% active basis)	Ex 1	Ex A*	Ex B*
C12-13 alkyl EO2 sulfate (18% branching)¹	20.7	20.7	20.7
C12-14 dimethyl amine oxide	6.9	6.9	6.9
C8-C10 alkyl polyglucoside²	2.0	-	-
C12-C14 alkyl polyglucoside³	-	2.0	-
NaCl	0.7	0.7	0.7
PPG (MW2000)	0.5	0.5	0.5
Alkoxylated polyethyleneimine⁴	0.5	0.5	0.5
Ethanol	1.0	1.0	1.0
MIT preservative	0.0075	0.0075	0.0075
Phenoxyethanol	0.08	0.08	0.08
Water and minors (perfume, dye)	bal.	bal.	bal.

pH (10% solution in demi water)	9.0	9.0	9.0

* Comparative
¹ made by sulfating ethoxylated C12-13 alkyl alcohol, sold under the tradename of Neodol 23-2^® and supplied by Shell
² sold under the tradename of Glucopon^® 215UP, supplied by BASF
³ sold under the tradename of Glucopon^® 600CSUP, supplied by BASF
⁴ Polyethyleneimine with a PEI backbone having a weight average molecular weight of 600g/mol and 24EO and 16PO units per alkoxylation chain, supplied by BASF

The results are given below:

Table 2: test results for the inventive and comparative liquid hand dishwashing detergent compositions

	Ex 1	Ex A*	Ex B*
Composition dissolution time at 20°C (s)	105	173	133
Suds Mileage in presence of particulate soil (1.25 mmol/l CaCO₃, 25°C)	110	103	100 (ref)
Viscosity upon initial dilution (20°C)	Thickens	Thickens	Maintains
Grease cleaning rate after soaking, 20°C)	118	58	100 (ref)

From comparing the results from inventive example 1 with comparative example B, it can be seen that formulating the liquid hand dishwashing composition to incorporate a short-chain alkyl polyglucoside, as described herein, improves composition dissolution, grease removal from surfaces and suspension into the wash solution as well as suds mileage in the presence of particulate soil, during low temperature cleaning of dishes. This is particularly surprising since longer chain alkyl polyglucosides have been found to reduce composition speed of dissolution, and impede grease lift off and suspension from surfaces during low temperature cleaning, in comparison to compositions which do not comprise the alkyl polyglucoside (comparative example B), while providing only a slight improvement in suds mileage in the presence of particulate soil. The increased composition speed dissolution for compositions of the present invention is particularly surprising when considering the observed initial thickening upon dilution for the composition comprising the short chain alkyl polyglucoside nonionic surfactant, since compositions having a higher initial viscosity typically have longer dissolution times.
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."

Claims

A method of cleaning dishes, the method comprising the step of:
contacting dishware with a liquid hand dishwashing detergent composition and water,

wherein:
a) the liquid hand dishwashing detergent composition comprises a surfactant system, wherein the surfactant system comprises:
a. alkyl polyglucoside, wherein the alkyl polyglucoside consists of short-chain alkyl polyglucoside nonionic surfactant, wherein the short-chain alkyl polyglucoside nonionic surfactant has an average alkyl carbon chain length of from 8 carbon atoms to 10 carbon atoms and a number average degree of polymerization of from 0.5 to 3.0;

b) the water has a temperature of 30 °C or less.
The method according to claim 1, wherein the water has a temperature of from 20 °C to 30 °C.
The method according to any of the preceding claims, wherein, prior to contacting the dishware with the liquid hand dishwashing detergent composition and the water, the liquid hand dishwashing detergent composition is delivered to a volume of the water to form a wash solution, and the dishware is contacted with the liquid hand dishwashing detergent composition and the water by immersing the dishware in the wash solution.
The method according to claim 3, wherein the wash solution comprises the liquid hand dishwashing detergent composition at a level of from 100 ppm to 10,000 ppm, preferably from 200 ppm to 5000 ppm, more preferably from 500 ppm to 2000 ppm.
The method according to claim 1 or claim 2, wherein, prior to contacting the dishware with the liquid hand dishwashing detergent composition and the water, the liquid hand dishwashing detergent composition and the water are combined on a device, preferably wherein the device is a brush, a sponge, a nonwoven material, or a woven material, more preferably wherein the device is a sponge.
The method according to claim 5 wherein the liquid hand dishwashing detergent composition and the water are combined in the device at ratios of from 25:75 to 1:99, preferably 15:85 to 1:99, more preferably 10:90 to 1:99.
The method according to any of the preceding claims, wherein in the liquid hand dishwashing detergent composition, at least 90%, preferably at least 95%, more preferably at least 98%, by weight of the short-chain alkyl polyglucoside surfactant has an alkyl carbon chain length of 8 to 10 carbon atoms.
The method according to any of the preceding claims, wherein in the liquid hand dishwashing detergent composition, the weight ratio of C8 alkyl polyglucoside to C10 alkyl polyglucoside is from 40:60 to 60:40.
The method according to any of the preceding claims, wherein the surfactant system comprises an anionic surfactant wherein the anionic surfactant comprises at least 50%, preferably at least 70%, preferably at least 90% by weight of the anionic surfactant of alkyl sulfated anionic surfactant, more preferably wherein the anionic surfactant consists of the alkyl sulfated anionic surfactant.
The method according to claim 9, wherein in the liquid hand dishwashing detergent composition, the alkyl sulfated anionic surfactant is an alkyl alkoxylated sulfate anionic surfactant, preferably wherein the alkyl alkoxylated sulfate anionic surfactant has an average degree of alkoxylation of less than 3.0, more preferably from 0.5 to 2.5, most preferably from 1.0 to 2.0.
The method according to claim 9 or 10, wherein in the liquid hand dishwashing detergent composition, the alkyl sulfated anionic surfactant has an alkyl chain comprising an average of from 8 to 18, preferably from 10 to 14, more preferably from 12 to 13 carbon atoms.
The method according to any of the preceding claims, wherein the liquid hand dishwashing detergent composition comprises from 5.0% to 50%, preferably from 8.0% to 45%, more preferably from 15% to 40%, by weight of the total composition of the surfactant system.
The method according to any of the preceding claims, wherein the surfactant system comprises from 5.0% to 40%, preferably from 7.5% to 30%, more preferably from 10% to 25% by weight of the composition of the anionic surfactant.
The method according to any of the preceding claims, wherein the surfactant system comprises from 0.1% to 8.0%, preferably from 0.5% to 4.0%, more preferably from 1.0% to 3.0% by weight of the composition of the short-chain alkyl polyglucoside nonionic surfactant.
The method according to any of the preceding claims, wherein the liquid hand dishwashing detergent composition comprises a co-surfactant selected from the group consisting of an amphoteric surfactant, a zwitterionic surfactant, and mixtures thereof.