Aqueous liquid dishwashing composition comprising an ammonium alkyl ether sulfate and alkylamidopropyl betaine

Aqueous liquid dishwashing compositions, for example, hand dishwashing compositions, need to have acceptable levels of foam production in order to be acceptable to the consumer. Foam production is a key attribute for consumers when choosing products, and foam production correlates directly with the consumer's perception of the efficacy of a dishwashing liquid. To achieve a desirable foam mileage (yield), manufacturers incorporate sufficient quantities of active ingredients (for example, surfactants) into compositions.

Dishwashing compositions must also meet consumer standards for clarity and viscosity, and must show stability in the various thermal storage conditions that may be encountered during manufacture, transport and supply. To achieve these properties, additional organic additives are frequently incorporated into the compositions. These include solubilizing alcohol, polymeric additives and hydrotropes.

Surfactants and other organic additives that are incorporated into liquid compositions increase the cost of manufacture of the compositions. Therefore, it would be desirable to provide an aqueous liquid dishwashing composition (for example a hand dishwashing composition), which is acceptable to the consumer, particularly with regard to foam production, viscosity, clarity and stability, yet which has reduced levels of organic material.

The present inventors have unexpectedly found that a surfactant mixture comprising the specific combination of an ethoxylated C 8 -C 18 alkyl ether sulfate surfactant having a low ethoxylation (EO) of from 0.4 to 1, and a C 8 -C 18 alkyl amidopropylbetaine surfactant, provides an equivalent foam mileage performance to commercial products having up to 10% more surfactant. The ethoxylated C 8 -C 18 alkyl ether sulfate surfactant having an ethoxylation (EO) of from 0.4 to 1 and C 8 -C 18 alkyl amidopropylbetaine surfactant act synergistically. The present inventors have additionally found that compositions comprising the aforementioned surfactant mixture require lower levels of solubilizing alcohol and other organic additives which are incorporated into conventional formulations to control viscosity, clarity and stability. Thus, the surfactant mixture of the present invention enables consumer acceptability to be maintained with a concurrent reduction in cost.

Accordingly, in a first aspect, the present invention provides an aqueous liquid dishwashing composition comprising i) at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant having an ethoxylation (EO) of from 0.4 to 1 and ii) at least one C 8 -C 18 alkyl amidopropylbetaine surfactant.

Preferably, the at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant has an ethoxylation (EO) of from 0.4 to 0.8 and more preferably, the at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant has an ethoxylation (EO) of about 0.6.

Optionally, the at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant comprises an ammonium or an alkali metal salt of a C 8 -C 18 alkyl ether sulfate, and preferably, the at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant comprises an ammonium salt of a C 8 -C 18 alkyl ether sulfate.

Preferably, the at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant comprises a C 10-16 alkyl ether sulfate surfactant and more preferably, the at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant comprises a C 12-15 alkyl ether sulfate surfactant.

Optionally, the at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant comprises ammonium lauryl ether sulfate surfactant, ammonium myristyl ether sulfate surfactant or a mixture thereof.

Preferably, the at least one C 8 -C 18 alkyl amidopropylbetaine surfactant comprises C 10-16 alkyl amidopropylbetaine, and more preferably, the at least one C 8 -C 18 alkyl amidopropylbetaine surfactant comprises C 12-14 alkyl amidopropylbetaine.

Optionally, the at least one C 8 -C 18 alkyl amidopropylbetaine surfactant comprises laurylamidopropylbetaine, myristylamidopropylbetaine, or a mixture thereof.

Preferably, the total amount of the at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant and the at least one C 8 -C 18 alkyl amidopropylbetaine surfactant is from 6 weight % to 30 weight % by total weight of the composition. More preferably, the total amount of the at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant and the at least one C 8 -C 18 alkyl amidopropylbetaine surfactant is from 15 weight % to 25 weight % by total weight of the composition. Most preferably, the total amount of the at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant and the at least one C 8 -C 18 alkyl amidopropylbetaine surfactant is from 17 weight % to 21 weight % by total weight of the composition. Optionally, the total amount of the at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant and the at least one C 8 -C 18 alkyl amidopropylbetaine surfactant is from 6 weight % to 9 weight % by total weight of the composition.

Optionally, the weight ratio of the at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant to the at least one C 8 -C 18 alkyl amidopropylbetaine surfactant is from 1:3 to 4:1, or from 1:3 to 3:1, or from 1:1 to 3:1, or from 1:1 to 2:1 on a surfactant active ingredient basis. Further optionally, the weight ratio of the at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant to the at least one C 8 -C 18 alkyl amidopropylbetaine surfactant is from 2.75:1 to 4:1 on a surfactant active ingredient basis.

Optionally, the composition is substantially free of surfactants other than the at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant and the at least one C 8 -C 18 alkyl amidopropylbetaine surfactant. Further optionally, the composition comprises surfactants other than at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant and the at least one C 8 -C 18 alkyl amidopropylbetaine surfactant in an amount of 0.5 weight % or less, by total weight of the composition.

Optionally, the composition comprises one or more viscosity modifiers in an amount of less than 3 weight % by total weight of the composition. Further optionally, the viscosity modifier is selected from a C 1 -C 5 alcohol, an ionic salt and a block copolymer. Still further optionally, the C 1 -C 5 alcohol comprises ethanol, and/or the ionic salt comprises one or both of sodium chloride and magnesium sulfate. Preferably, the composition comprises ethanol in an amount of 2 weight % or less, or 1 weight % or less by total weight of the composition.

Optionally, the composition has a viscosity of from 500 to 1200 mPas as measured on a Brookfield RVT Viscometer using spindle 21 at 20 RPM at 25° C. Further optionally, the composition is a light duty hand dishwashing composition.

In a second aspect, provided is a use, in an aqueous liquid dishwashing composition, of a combination of i) at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant having an ethoxylation (EO) of from 0.4 to 1 and ii) at least one C 8 -C 18 alkyl amidopropylbetaine surfactant, for enhancing foam production of the composition.

Optionally, the composition is as defined herein.

In a third aspect, provided is a use, in an aqueous liquid dishwashing composition, of a combination of i) at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant having an ethoxylation (EO) of from 0.4 to 1 and ii) at least one C 8 -C 18 alkyl amidopropylbetaine surfactant, for controlling the viscosity of the composition.

Optionally, the composition is as defined herein.

In a fourth aspect, provided is a use, in an aqueous liquid dishwashing composition, of a combination of i) at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant having an ethoxylation (EO) of from 0.4 to 1 and ii) at least one C 8 -C 18 alkyl amidopropylbetaine surfactant, for inhibiting or preventing gelling of the composition at a temperature below 6° C.

Optionally, the composition is as defined herein.

Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

As used throughout, ranges are used as shorthand for describing each and every value that is within the range. Any value within the range can be selected as the terminus of the range. In addition, all references cited herein are hereby incorporated by referenced in their entireties. In the event of a conflict in a definition in the present disclosure and that of a cited reference, the present disclosure controls.

Unless otherwise specified, all percentages and amounts expressed herein and elsewhere in the specification should be understood to refer to percentages by weight. The amounts given are based on the active weight of the material.

In one arrangement, provided is an aqueous liquid composition comprising i) at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant having an ethoxylation of from 0.4 to 1 and ii) at least one C 8 -C 18 alkyl amidopropylbetaine surfactant.

In preferred embodiments, the composition is a dishwashing liquid such as a light duty hand dishwashing liquid.

Ethoxylated C 8 -C 18 Alkyl Ether Sulfate Surfactant

The ethoxylated C 8 -C 18 alkyl ether sulfate surfactant may be represented by general formula 1:

RO(CH 2 CH 2 O) x SO 3 M  Formula 1:

“R” represents an alkyl group having from 8 to 18 carbon atoms, preferably from 10 to 16 carbon atoms, and more preferably from 12 to 14 carbon atoms. The alkyl group may be linear or branched. The ethoxylated C 8 -C 18 alkyl ether sulfate surfactant may comprise or consist of one or a mixture of ethoxylated C 8 -C 18 alkyl ether sulfates. Thus, in one embodiment, the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant comprises at least one C 10-16 alkyl ether sulfate surfactant. Preferably, the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant comprises at least one C 12-15 alkyl ether sulfate surfactant. More preferably, the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant comprises lauryl ether sulfate surfactant, myristyl ether sulfate surfactant, or a mixture thereof. In some embodiments, the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant consists essentially of an ethoxylated C 12-15 alkyl ether sulfate, lauryl ether sulfate surfactant, myristyl ether sulfate surfactant or a mixture of lauryl ether sulfate surfactant and myristyl ether sulfate surfactant (lauryl/myristyl ether sulfate surfactant).

“x” refers to the average ethoxylation level (referred to hereinafter as “EO”), and represents the average number of moles of ethylene oxide units per mole of alkyl units. In one embodiment, the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant has an average ethoxylation (EO) of from 0.4 to 1 or less than 1, from 0.5 to 1 or less than 1, or from 0.6 to 1 or less than 1. Preferably, the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant has an EO of from 0.4 to 0.7, from 0.4 to 0.8, from 0.4 to 0.9, from 0.5 to 0.7, from 0.5 to 0.8, from 0.5 to 0.9, from 0.6 to 0.7, from 0.6 to 0.8, or from 0.6 to 0.9. Typically, the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant has an EO of 0.6.

“M” is a cation selected from alkali metals (for example, sodium and potassium), alkaline earth metals (for example, calcium and magnesium), ammonium, or substituted ammonium. Specific examples of substituted ammonium cations include methyl-, dimethyl-, trimethyl-ammonium. Other examples of substituted ammonium cations include quaternary ammonium cations, such as tetramethyl-ammonium, dimethyl piperidinium and cations derived from alkanolamines (for example, monoethanolamine, diethanolamine, and triethanolamine, and mixtures thereof). Typically, the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant comprises an ammonium or an alkali metal salt.

In a preferred arrangement, the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant comprises ammonium lauryl ether sulfate surfactant, ammonium myristyl ether sulfate surfactant, or a mixture thereof (ammonium lauryl/myristyl ether sulfate surfactant). In another arrangement, the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant consists essentially of ammonium lauryl ether sulfate surfactant, ammonium myristyl ether sulfate surfactant, or a mixture thereof (ammonium lauryl/myristyl ether sulfate surfactant). In yet another arrangement, the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant comprises or consists of sodium lauryl ether sulfate surfactant, sodium myristyl ether sulfate surfactant, or a mixture thereof (sodium lauryl/myristyl ether sulfate surfactant).

The ethoxylated alkyl ether sulfate may be made by sulfating the condensation product of ethylene oxide and C 8-18 alkanol, and neutralizing the resultant product. The C 8-18 alkanol is typically reacted with 0.4 to 1 mole ethylene oxide per mole of alkanol, to generate an average EO value of 0.4 to 1. The C 8-18 alkanol may be derived from plant sources (e.g. coconut or palm oil) which may be “mid-cut” to specifically provide a C 12-15 alkanol source, or the source of C 8-18 alkanol may be synthetic. A preferred source is Shell Neodol™ 25 alcohol.

C 8 -C 18 Alkyl Amidopropylbetaine

The C 8 -C 18 alkyl amidopropylbetaine may be represented by general formula 2:

wherein R′ represents a linear or branched “C n H 2n+1 ” group, having between 7 and 17 carbons such that the alkyl amidopropylbetaine is a C 8 -C 18 alkyl amidopropylbetaine.

The C 8 -C 18 alkyl amidopropylbetaine surfactant may comprise or consist of one or a mixture of C 8 -C 18 alkyl amidopropylbetaines.

In one embodiment, the C 8 -C 18 alkyl amidopropylbetaine comprises cocoamidopropylbetaine or C 10 -C 16 alkyl amidopropylbetaine. More preferably, the C 8 -C 18 alkyl amidopropylbetaine comprises C 12 -C 14 alkyl amidopropylbetaine or a “mid-cut” C 12 -C 14 cocoamidopropylbetaine. Most preferably, the C 8 -C 18 alkyl amidopropylbetaine comprises laurylamidopropylbetaine (INCI name lauramidopropyl betaine), myristylamidopropyl betaine INCI name myristamidopropyl betaine), or a mixture thereof (lauramidopropyl betaine/myristamidopropyl betaine). In some embodiments, the C 8 -C 18 alkyl amidopropylbetaine consists of C 12 -C 14 alkyl amidopropylbetaine or a “mid-cut” C 12 -C 14 cocoamidopropylbetaine. In other embodiments, the C 8 -C 18 alkyl amidopropylbetaine consists of laurylamidopropylbetaine, myristylamidopropylbetaine, or a mixture thereof.

The present inventors have found that ethoxylated C 8 -C 18 alkyl ether sulfate surfactant having an ethoxylation (EO) of from 0.4 to 1, and C 8 -C 18 alkyl amidopropylbetaine surfactant, act synergistically to provide an enhanced foam mileage performance (i.e. enhanced foam yield) as compared to other surfactant combinations. This advantageously allows the total amount of surfactant (on a surfactant active ingredient basis) to be reduced.

Thus, in one arrangement, the total amount of the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) and the C 8 -C 18 alkyl amidopropylbetaine surfactant is from 6 weight % to 30 weight % by total weight of the composition, on a surfactant active ingredient basis. Preferably, the total amount of the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) and the C 8 -C 18 alkyl amidopropylbetaine surfactant is from 10 weight % to 25 weight %, or from 15 weight % to 25 weight %, or from 20 weight % to 25 weight %, or from 18 weight % to 22 weight %, or from 20 weight % to 22 weight % by total weight of the composition, on a surfactant active ingredient basis. More preferably, the total amount of the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) and the C 8 -C 18 alkyl amidopropylbetaine surfactant is from 18 weight % to 20 weight % or to 21 weight %, or from 17 weight % to 20 weight % or to 21 weight %, by total weight of the composition, on a surfactant active ingredient basis. In some embodiments, the total amount of the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) and the C 8 -C 18 alkyl amidopropylbetaine surfactant is 17 weight %, 18 weight %, 19 weight %, 20 weight %, or 21 weight %, by total weight of the composition, on a surfactant active ingredient basis.

In another arrangement, the total amount of the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) and the C 8 -C 18 alkyl amidopropylbetaine surfactant is from 5 weight % to 10 weight %, or from 6 weight % to 9 weight % by total weight of the composition, on a surfactant active ingredient basis. In some embodiments, the total amount of the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) and the C 8 -C 18 alkyl amidopropylbetaine surfactant is 6 weight %, 7 weight %, 8 weight %, or 9 weight % by total weight of the composition, on a surfactant active ingredient basis.

Typically, the weight ratio of the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) to the C 8 -C 18 alkyl amidopropylbetaine surfactant is from 1:3 to 4:1, or from 1:3 to 3:1, or from 1:3 to 2:1 or from 1:3 to 1:1, on a surfactant active ingredient basis. In some embodiments, the weight ratio of the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) to the C 8 -C 18 alkyl amidopropylbetaine surfactant is from 1:1 to 3:1, or from 1:1 to 2:1, on a surfactant active ingredient basis. In further embodiments, the weight ratio of the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) to the C 8 -C 18 alkyl amidopropylbetaine surfactant is from 2:1 to 4:1, from 2.25:1 to 4:1, from 2.5:1 to 4:1, from 2.75:1 to 4:1 or from 3:1 to 4:1, on a surfactant active ingredient basis.

In one arrangement, the total amount of the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) and the C 8 -C 18 alkyl amidopropylbetaine surfactant is from 6 weight % to 9 weight % by total weight of the composition on a surfactant active ingredient basis, and the weight ratio of the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) to the C 8 -C 18 alkyl amidopropylbetaine surfactant is from 1:1 to 3:1 on an active basis. In a specific embodiment, the total amount of the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) and the C 8 -C 18 alkyl amidopropylbetaine surfactant is 9 weight % and the weight ratio of the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) to the C 8 -C 18 alkyl amidopropylbetaine surfactant is from 1:1 to 3:1, on a surfactant active ingredient basis. In another embodiment, the total amount of the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) and the C 8 -C 18 alkyl amidopropylbetaine surfactant is 8 weight % and the weight ratio of the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) to the C 8 -C 18 alkyl amidopropylbetaine surfactant is 1.4:1, on a surfactant active ingredient basis.

In another arrangement, the total amount of the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) and the C 8 -C 18 alkyl amidopropylbetaine surfactant is from 18 weight % to 22 weight %, or from 20 weight % to 22 weight %, or from 20 weight % to 21 weight % by total weight of the composition on a surfactant active ingredient basis, and the weight ratio of the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) to the C 8 -C 18 alkyl amidopropylbetaine surfactant is from 2.75:1 to 4:1, on a surfactant active ingredient basis. In yet another arrangement, the total amount of the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) and the C 8 -C 18 alkyl amidopropylbetaine surfactant is from 17 weight % to 22 weight %, or from 17 weight % to 21 weight %, or from 17 weight % to 20 weight % by total weight of the composition on a surfactant active ingredient basis, and the weight ratio of the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) to the C 8 -C 18 alkyl amidopropylbetaine surfactant is from 2.75:1 to 4:1, on a surfactant active ingredient basis.

Additional Optional Ingredients

The aqueous liquid dishwashing compositions may comprise optional ingredients well known to persons skilled in the art of cleaning compositions such as additional surfactants, hydrotopes, viscosity modifiers, stabilizers, enzymes, dyes, perfumes, and mixtures thereof.

Surfactants

The specific combination of an ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) and a C 8 -C 18 alkyl amidopropylbetaine surfactant effectively provides enhanced foam production and provides cleaning efficacy. As used herein, the term “foam production” refers to one or more of foam mass, foam volume and foam stability. Foam production may be assessed using various methods that would be known to persons skilled in the art of detergent solutions. A specific method of assessing foam production comprises using an automated miniplate tester as described previously in U.S. Pat. No. 4,556,509. This test is described in further detail in the Examples.

Thus, in some embodiments, the total amount of surfactants in the composition other than the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) and the C 8 -C 18 alkyl amidopropylbetaine surfactant is less than 10 weight %, less than 5 weight %, less than 4 weight %, less than 3 weight %, less than 2 weight %, less than 1 weight % or less than 0.5 weight % by total weight of the composition on a surfactant active ingredient basis. In other embodiments, the aqueous liquid dishwashing composition of the present invention is substantially free of any other surfactants. By “substantially free”, it is meant that the total amount of surfactants in the composition other than the ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) and the C 8 -C 18 alkyl amidopropylbetaine surfactant is less than 2 weight %, less than 1 weight % or less than 0.5 weight % by total weight of the composition, on a surfactant active ingredient basis.

If the composition comprises additional surfactants, these may be selected from the group consisting of anionic, nonionic, cationic and amphoteric surfactants. These would be known to the person skilled in the art. However, non-limiting examples are provided below.

Additional anionic surfactants that may be present in the compositions are water soluble and include, but are not limited to, sodium, potassium, ammonium, and ethanolammonium salts of linear C 8 -C 16 alkyl benzene sulfonates, alkyl ether carboxylates, C 10 -C 20 paraffin sulfonates, C 8 -C 25 alpha olefin sulfonates, C 8 -C 18 alkyl sulfates, and mixtures thereof.

Additional nonionic surfactants that may be present in the compositions include the primary aliphatic alcohol ethoxylates, secondary aliphatic alcohol ethoxylates, alkylphenol ethoxylates, and condensates of ethylene oxide with sorbitan fatty acid esters such as the TWEEN™ surfactants. Other suitable water-soluble nonionic surfactants are marketed under the trade name PLURONIC™. The compounds are formed by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol.

Suitable, non-limiting examples of amphoteric detergent surfactants that are useful include derivatives of aliphatic or heterocyclic secondary and ternary amines in which the aliphatic moiety can be straight chain or branched, and in which at least one aliphatic substituent contains an anionic water-solubilizing group. Amine oxides are also suitable amphoteric surfactants which may be incorporated into the compositions of the present invention.

Viscosity Modifiers

The compositions may optionally comprise one or more additional viscosity modifiers or control agents. Such agents include, but are not limited to, polypropylene glycol, linear C 1 -C 5 alcohols such as ethanol, polysorbate 20 (TWEEN™20), polyethylene oxide-polypropylene block copolymers (such as Pluronic™ L44, Pluronic™ L35, or Pluronic™ L31 poloxamers), polyethylene glycol 55 (PEG-55), glycerin, diethylene glycol, GLUCAM™ P-10 propylene glycol ether of methyl glucose with 10 polypropylene oxide units, PLURIOL™ E300 alkoxylates based on ethylene oxide and propylene oxide, sodium cumene sulfonate (SCS), sodium xylene sulfonate (SXS), GLUCAM™ P-20 propylene glycol ether of methyl glucose with 20 polypropylene oxide units, GLUCAM™ E-20 ethylene glycol ether of methyl glucose with 20 polyethylene oxide units, GLUCAM™ E-10 ethylene glycol ether of methyl glucose with 10 polyethylene oxide units, and short chain ethoxylated propoxylated alcohols such as PPG2-Buteth-3, PPG3-Buteth-5, or PPG5-Buteth-7.

The compositions may further comprise one or more ionic additives as viscosity modifiers. The ionic additive may be a salt, which can include any desirable salt. Examples of salts include, but are not limited to, sodium chloride and magnesium sulfate.

The present inventors have unexpectedly found that the specific combination of an ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) and a C 8 -C 18 alkyl amidopropylbetaine surfactant in an aqueous liquid dishwashing composition is effective in providing a desirable viscosity to the composition and obviates the need for large quantities of viscosity modifiers found in conventional dishwashing compositions. In preferred embodiments, the composition has a desirable viscosity of from 500 to 1200 mPas, and more preferably from 600 to 900 mPas, as measured on a Brookfield RVT Viscometer using spindle 21 at 20 RPM at 25° C.

Thus, in one embodiment, the composition comprises one or more viscosity modifiers (the term “viscosity modifier” as used herein is not intended to include ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) and C 8 -C 18 alkyl amidopropylbetaine surfactant), in an amount of less than 5 weight %, less than 4 weight %, less than 3 weight %, or less than 2 weight % by total weight of the composition, optionally, wherein the viscosity modifiers are selected from C 1 -C 5 alcohols, ionic salts, and block copolymers, and further optionally, wherein the C 1 -C 5 alcohol is ethanol, and wherein the ionic salt is sodium chloride and/or magnesium sulfate.

Additionally, whilst ethanol is known to be an effective viscosity enhancer in liquid compositions, ethanol may form an undesirable gel phase at temperatures below 0° C., causing an evident phase separation at the bottom of the container containing the composition. This is undesirable for the consumer. Additionally, a high ethanol content increases the cost of the composition. As the specific combination of an ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) and a C 8 -C 18 alkyl amidopropylbetaine surfactant provides desirable viscosity properties, the amount of ethanol in the compositions may be reduced. Accordingly, in one embodiment, the compositions comprise ethanol in an amount of less than 10 weight %, 5 weight %, 4 weight %, 3 weight %, or 2 weight % or 1 weight % by total weight of the composition. In other embodiments, the compositions comprise ethanol in an amount of less than 1.5 weight % or less than 1.8 weight. % by total weight of the composition. In further embodiments, the compositions are substantially free of ethanol.

Furthermore, unlike conventional viscosity modifiers such as ethanol, the specific combination of an ethoxylated C 8 -C 18 alkyl ether sulfate surfactant (EO 0.4 to 1) and a C 8 -C 18 alkyl amidopropylbetaine surfactant, whilst providing desirable viscosity properties, does not reduce the stability of the compositions. Thus, typically, the compositions are resistant to gel formation and phase separation at cold temperatures. In some illustrative embodiments, the compositions exhibit stability (as determined by an absence of gel formation or phase separation at 25° C.) having been stored at −4° C., −10° C. or at −30° C. for at least three weeks.

Solvents

The compositions may also contain solvents or salts to modify the cleaning, stability and rheological properties of the composition.

Solvents can include any water soluble solvents. Water soluble solvents include, but are not limited to, C 2-4 mono, dihydroxy, or polyhydroxy alkanols and/or an ether or diether, such as isopropanol, ethanol, diethylene glycol monobutyl ether, dipropylene glycol methyl ether, diproyleneglycol monobutyl ether, propylene glycol n-butyl ether, propylene glycol, and hexylene glycol, urea, and alkali metal cumene, alkali metal toluene, or alkali metal xylene sulfonates such as sodium cumene sulfonate and sodium xylene sulfonate.

Generally, water is included in the compositions. The amount of water is variable and depends on the amounts of other materials added to the composition. Typically the compositions comprise from 60 weight % to 94 weight % water.

Additional optional ingredients may be included to provide added functional effect or to make the compositions more attractive. Such ingredients include, but are not limited to, perfumes, fragrances, colorants, pigments, dyes, abrasive agents, disinfectants, enzymes, antioxidants, bleaches, chelating agents, antibacterial agents/preservatives, optical brighteners, opacifiers, hydrotropes, or combinations thereof. These ingredients would be known to persons skilled in the art of cleaning liquid manufacture.

The compositions can be made by simple mixing methods from readily available components which, on storage, do not adversely affect the entire composition. Mixing can be done by any mixer that forms the composition. Examples of mixers include, but are not limited to, static mixers and in-line mixers.

The composition can be provided in any type and shape of container that is compatible with the composition. Non-limiting examples of containers are made from plastic or glass. For consumer convenience, plastic may be chosen. The plastic can be any type of plastic. Examples of plastic include, but are not limited to, polyethylene tetra phthalate (PET), polyethylene, polypropylene, or polyvinyl chloride. Container properties, such as clarity, gloss, color, and shape can be selected to provide a desired aesthetic effect.

Uses

The compositions defined herein are suitable for use as dishwashing liquids, and in particular, light duty hand dishwashing liquids. In some embodiments, the compositions defined herein may also be suitable for cleaning other hard surfaces (such as glass, metal and the like).

As demonstrated in the following examples, the present inventors have unexpectedly found that the specific combination of an ethoxylated C 8 -C 18 alkyl ether sulfate surfactant having an ethoxylation (EO) of from 0.4 to 1 and a C 8 -C 18 alkyl amidopropylbetaine surfactant is effective in enhancing foam production at a lower surfactant active ingredient level, as compared to other surfactant compositions. The inventors have further found that the incorporation of the specific combination of an ethoxylated C 8 -C 18 alkyl ether sulfate surfactant having an ethoxylation (EO) of from 0.4 to 1 and a C 8 -C 18 alkyl amidopropylbetaine surfactant into aqueous liquid compositions is effective in modulating the viscosity of the compositions, thus obviating the need for additional viscosity control agents.

Accordingly, further provided is a use, in an aqueous liquid dishwashing composition, of a combination of i) at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant having an ethoxylation (EO) of from 0.4 to 1 and ii) at least one C 8 -C 18 alkyl amidopropylbetaine surfactant, for enhancing foam production of the composition. The composition may be as defined herein.

There is additionally provided a use, in an aqueous liquid dishwashing composition, of a combination of i) at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant having an ethoxylation (EO) of from 0.4 to 1 and ii) at least one C 8 -C 18 alkyl amidopropylbetaine surfactant, for controlling (for example, decreasing) the viscosity of the composition. The composition may be as defined herein.

The present inventors have additionally found that in the presence of the specific combination of an ethoxylated C 8 -C 18 alkyl ether sulfate surfactant having an ethoxylation (EO) of from 0.4 to 1 and a C 8 -C 18 alkyl amidopropylbetaine surfactant, fewer additives are required to maintain composition stability (i.e. preventing gelling and/or phase separation and maintaining viscosity over time) at low temperatures (for example, below 6° C.).

Accordingly, further provided is a use, in an aqueous liquid dishwashing composition, of a combination of i) at least one ethoxylated C 8 -C 18 alkyl ether sulfate surfactant having an ethoxylation (EO) of from 0.4 to 1 and ii) at least one C 8 -C 18 alkyl amidopropylbetaine surfactant, for inhibiting or preventing gelling and/or phase separation of the composition, and/or for improving the stability of the composition, at a temperature below 6° C.

The following examples illustrate compositions of the invention. Unless otherwise specified, all percentages are by weight. The abbreviation “AI” refers to the total amount of surfactant active ingredient(s). The exemplified compositions are illustrative and do not limit the scope of the invention.