Water-based light-duty liquid detergent formulation

Abstract

An aqueous light-duty liquid detergent formulation is provided, the formulation comprising water, a zwitterionic surfactant, and an alcohol ethoxy sulfate surfactant of formula I: [Formula 1] JPEG2025531097000026.jpg25170 In the formula, each R 1 and R 2 independently, C 1~16 is an alkyl group, and R 1 and R 2 The total number of carbon atoms in is 7 to 17, and M + is -SO3 of formula I - It is the cation that balances the negative charge of the anion, and n is 1 in 95-100 mol % of the alcohol ethoxy sulfate surfactant of formula I.

Description

[Technical Field]

[0001] The present invention relates to aqueous light-duty liquid detergent formulations. Specifically, the present invention relates to aqueous light-duty liquid detergent formulations comprising water, a zwitterionic surfactant, and an alcohol ethoxy sulfate surfactant of formula I:

[0002] [ka] In the formula, each R 1 and R 2 independently, C 1~16 is an alkyl group, and R 1 and R 2 The total number of carbon atoms in is 7 to 17, and M + is -SO3 of formula I - It is the cation that balances the negative charge of the anion, and n is 1 in 95-100 mol % of the alcohol ethoxy sulfate surfactant of formula I.

[0003] Aqueous cleaning compositions, such as floor care formulations, hard surface cleaning formulations, and personal care formulations, are widely used, including for example, cleaning hard surfaces such as floors, counters, walls, tables, and other objects made of, for example, wood, stone, laminate, ceramic, and plastic materials that require periodic cleaning of accumulated dirt, oil, grease, and other contaminants.

[0004] Aqueous light-duty liquid detergent formulations are commonly used in hand dishwashing detergents, hard surface cleaners, and some laundry applications. These aqueous light-duty liquid detergent formulations typically contain anionic surfactants that are the primary foaming agents, along with secondary surfactants. Alkyl ethoxy sulfate anionic surfactants (e.g., alcohol ethoxy sulfate surfactants) have established use in various aqueous light-duty liquid detergent formulations. Traditional AES anionic surfactants, however, are associated with undesirable 1,4-dioxane content. Regulatory agencies are increasingly restricting the amount of 1,4-dioxane that can be present in consumer products. For example, New York State has banned all but trace amounts of 1,4-dioxane in cleaning products. Typically, consumer products must contain less than 10 parts per million (ppm) by weight of 1,4-dioxane to comply with regulations. The inclusion of alkyl ethoxy sulfate anionic surfactants may be one factor contributing to the unintentional incorporation of 1,4-dioxane into consumer products.

[0005] The inclusion of 1,4-dioxane in conventional AES surfactants is believed to occur at multiple points. The first point of 1,4-dioxane formation in conventional AES surfactants is believed to occur during the sulfation process of alcohol ethoxylates to produce alcohol ethoxy sulfates. The ethoxylated alcohol intermediates for the production of conventional alcohol ethoxy sulfate surfactants are typically produced via ethoxylation (i.e., reaction of alcohol with ethylene oxide), which results in a distribution of alcohol ethoxylate oligomers. It is believed that 1,4 dioxane may be formed under sulfation process conditions during the production of conventional AES surfactants. The second point of 1,4 dioxane formation associated with conventional AES surfactants is believed to occur during handling and processing of conventional AES surfactants. Handling and processing of conventional AES surfactants often involves acidic conditions at ambient or elevated temperatures. Prolonged exposure of conventional AES surfactants and their alcohol ethoxylate precursors to an acidic environment can result in the formation of 1,4 dioxane. Additionally, exposure to elevated temperatures (eg, up to 280° C.) during processing, storage, and / or handling can result in decomposition of conventional AES surfactants, resulting in the formation of dioxane.

[0006] Traditionally, 1,4-dioxane content in conventional AES surfactants and products incorporating such surfactants has been addressed through the use of stripping techniques. For example, if the 1,4-dioxane concentration exceeds a target threshold, a stripping process is used to remove excess 1,4-dioxane from the conventional AES surfactant or products incorporating it. Stripping processes are not only expensive and time-consuming, but also do not guarantee compliance with increasingly stringent regulatory requirements. Furthermore, because 1,4-dioxane can form over time in response to how the conventional AES surfactant or product is handled and further processed, any previously applied stripping techniques may be rendered ineffective by the generation of new 1,4-dioxane. As such, ensuring that products containing AES surfactants comply with the appropriate regulations at the time of sale to the end consumer is a challenging task.

[0007] Therefore, there remains a need for aqueous light-duty liquid detergent formulations having anionic alcohol ethoxy sulfate surfactants that resist the formation of 1,4-dioxane both during the sulfation process to form the surfactant and when the alcohol ethoxy sulfate surfactant is subsequently exposed to high temperatures up to 280°C. Summary of the Invention

[0008] The present invention provides an aqueous light-duty liquid detergent formulation, the formulation comprising water, a zwitterionic surfactant, and an alcohol ethoxy sulfate surfactant of formula I:

[0009] [ka] In the formula, each R 1 and R 2 independently, C 1~16 is an alkyl group, and R 1 and R 2 The total number of carbon atoms in is 7 to 17, and M + is -SO3 of formula I - It is the cation that balances the negative charge of the anion, and n is 1 in 95-100 mol % of the alcohol ethoxy sulfate surfactant of formula I.

[0010] The present invention provides an aqueous light-duty liquid detergent formulation, the formulation comprising water, a zwitterionic surfactant, and an alcohol ethoxy sulfate surfactant of formula I, wherein each R 1 and R 2 independently, C 1~16 is an alkyl group, and R 1 and R 2 The total number of carbon atoms in is 7 to 17, and M + is -SO3 of formula I -is a cation that balances the negative charge of the anion, and n is 1 in 95-100 mol % of the alcohol ethoxy sulfate surfactant of formula I, which contains less than 9 ppm of 1,4-dioxane.

[0011] The present invention provides an aqueous light-duty liquid detergent formulation, the formulation comprising water, a zwitterionic surfactant, and an alcohol ethoxy sulfate surfactant of formula I, wherein each R 1 and R 2 independently, C 1~16 is an alkyl group, and R 1 and R 2 The total number of carbon atoms in is 7 to 17, and M + is -SO3 of formula I - is a cation that balances the negative charge of the anion, and n is 1 in 95-100 mol % of the alcohol ethoxy sulfate surfactant of formula I, the alcohol ethoxy sulfate surfactant of formula I contains less than 9 ppm 1,4-dioxane, and the alcohol ethoxy sulfate surfactant of formula I has increased thermal stability (preferably enhanced thermal stability).

[0012] The present invention provides an aqueous light-duty liquid detergent formulation, the formulation comprising water, a zwitterionic surfactant, and an alcohol ethoxy sulfate surfactant of formula I, wherein each R 1 and R 2 independently, C 1~16 is an alkyl group, and R 1 and R 2 The total number of carbon atoms in is 7 to 17, and M + is -SO3 of formula I - n is a cation that balances the negative charge of the anion, and n is 1 in 95 to 100 mol % of the alcohol ethoxy sulfate surfactant of formula I, the alcohol ethoxy sulfate surfactant of formula I contains less than 9 ppm of 1,4-dioxane, and the aqueous light-duty liquid detergent formulation contains less than 1 wt % of the alcohol sulfate surfactant of formula II, based on the solids weight of the aqueous light-duty liquid detergent formulation;

[0013] [ka] In the formula, each R 3 and R 4 independently, C 1~16 is an alkyl group, and R 3 and R 4 The total number of carbon atoms in A is 7 to 17. + is -SO3 in formula II - It is the cation that balances the negative charge on the anion.

[0014] The present invention provides an aqueous light-duty liquid detergent formulation, the formulation comprising water, an organic solvent, a zwitterionic surfactant, and an alcohol ethoxy sulfate surfactant of formula I, wherein each R 1 and R 2 independently, C 1~16 is an alkyl group, and R 1 and R 2 The total number of carbon atoms in is 7 to 17, and M + is -SO3 of formula I - is a cation that balances the negative charge of the anion, and n is 1 in 95 to 100 mol % of the alcohol ethoxy sulfate surfactant of formula I, the alcohol ethoxy sulfate surfactant of formula I contains less than 9 ppm 1,4-dioxane, and the aqueous light-duty liquid detergent formulation contains less than 1 wt % of the alcohol sulfate surfactant of formula II, based on the solids weight of the aqueous light-duty liquid detergent formulation, 3 and R 4 independently, C 1~16 is an alkyl group, and R 3 and R 4 The total number of carbon atoms in A is 7 to 17. + is -SO3 in formula II - It is the cation that balances the negative charge on the anion.

[0015] The present invention provides an aqueous light-duty liquid detergent formulation comprising 50 to 97 wt. % water, based on the weight of the aqueous light-duty liquid detergent formulation; 0.1 to 10 wt. % organic solvent, based on the weight of the aqueous light-duty liquid detergent formulation; 0.1 to 10 wt. % zwitterionic surfactant, based on the weight of the aqueous light-duty liquid detergent formulation; and 0.1 to 20 wt. % alcohol ethoxy sulfate surfactant of Formula I, based on the weight of the aqueous light-duty liquid detergent formulation, wherein each R 1 and R 2 independently, C 1~16 is an alkyl group, and R 1 and R 2 The total number of carbon atoms in is 7 to 17, and M + is -SO3 of formula I - is a cation that balances the negative charge of the anion, and n is 1 in 95 to 100 mol % of the alcohol ethoxy sulfate surfactant of formula I, the alcohol ethoxy sulfate surfactant of formula I contains less than 9 ppm 1,4-dioxane, and the aqueous light-duty liquid detergent formulation contains less than 1 wt % of the alcohol sulfate surfactant of formula II, based on the solids weight of the aqueous light-duty liquid detergent formulation, 3 and R 4 independently, C 1~16 is an alkyl group, and R 3 and R 4 The total number of carbon atoms in A is 7 to 17. + is -SO3 in formula II - It is the cation that balances the negative charge on the anion.

[0016] The present invention provides a method for hand washing an item, the method comprising providing an item, the item being selected from the group consisting of at least one of dishes, glassware, silverware, pots, pans, and delicates; providing an aqueous light-duty liquid detergent formulation of the present invention; manually contacting the item with the aqueous light-duty liquid detergent formulation; and rinsing the aqueous light-duty liquid detergent formulation from the item. DETAILED DESCRIPTION OF THE INVENTION

[0017] The inventors have surprisingly discovered an alcohol ethoxy sulfate surfactant of formula I,

[0018] [ka] In the formula, each R 1 and R 2 But independently, C 1~16 is an alkyl group, and R 1 and R 2 The total number of carbon atoms in + In formula I, -SO3 - It has been found that surfactants having a cation that balances the negative charge of the anion, and n being 1 in 95-100 mol % of the alcohol ethoxy sulfate surfactant of formula I, resist forming 1,4 dioxane both during the sulfation process to form the alcohol ethoxy sulfate surfactant of formula I, and thereafter when the alcohol ethoxy sulfate surfactant of formula I is exposed to elevated temperatures up to 280° C. during processing, storage, and / or handling.

[0019] The inventors have also surprisingly discovered an alcohol ethoxy sulfate surfactant of formula I, wherein each R 1 and R 2 But independently, C 1~16 is an alkyl group, and R 1 and R 2 The total number of carbon atoms in + In formula I, -SO3 - It has been found that surfactants having a cation that balances the negative charge of the anion, where n is 1 in 95-100 mol % of the alcohol ethoxy sulfate surfactants of formula I, provide improved thickening of aqueous light-duty liquid detergent formulations and better suds mileage for cleaning surfaces in higher oil load environments compared to conventional AES surfactants.

[0020] Unless otherwise indicated, ratios, percentages, parts, etc. are by weight (for example, "ppm" means parts per million by weight).

[0021] The term "solids weight" as used herein and in the appended claims with respect to aqueous light-duty liquid detergent formulations and alcohol ethoxy sulfate surfactants of Formula I means dry weight, i.e., excluding any water that may be present.

[0022] Preferably, the aqueous light-duty liquid detergent formulation of the present invention is a hard surface cleaning formulation. More preferably, the aqueous light-duty liquid detergent formulation of the present invention is a hand dishwashing detergent.

[0023] Preferably, the aqueous light-duty liquid detergent formulation of the present invention comprises water (preferably 25 to 99 wt % (more preferably 50 to 98 wt %, even more preferably 60 to 97 wt %, most preferably 65 to 80 wt %) of water, based on the weight of the aqueous light-duty liquid detergent formulation), a zwitterionic surfactant (preferably 0.01 to 15 wt % (more preferably 0.1 to 10 wt %, even more preferably 0.5 to 7.5 wt %, most preferably 1 to 5 wt %) of zwitterionic surfactant, based on the weight of the aqueous light-duty liquid detergent formulation), and an alcohol ethoxy sulfate surfactant of formula I (preferably 0.01 to 35 wt % (more preferably 0.1 to 20 wt %, even more preferably 1 to 15 wt %, most preferably 2.5 to 10 wt %) of alcohol ethoxy sulfate surfactant of formula I, based on the weight of the aqueous light-duty liquid detergent formulation),

[0024] [ka] In the formula, each R 1 and R 2 independently, C 1~16 is an alkyl group, and R 1 and R 2 The total number of carbon atoms in is 7 to 17, and M + is -SO3 of formula I -It is the cation that balances the negative charge of the anion, and n is 1 in 95-100 mol % of the alcohol ethoxy sulfate surfactant of formula I.

[0025] Preferably, the aqueous light-duty liquid detergent formulation of the present invention comprises 25 to 99 wt % (more preferably 50 to 98 wt %, even more preferably 60 to 97 wt %, and most preferably 65 to 80 wt %) of water based on the weight of the aqueous light-duty liquid detergent formulation. More preferably, the aqueous light-duty liquid detergent formulation of the present invention comprises 25 to 99 wt % (more preferably 50 to 98 wt %, even more preferably 60 to 97 wt %, and most preferably 65 to 80 wt %) of water based on the weight of the aqueous light-duty liquid detergent formulation, and the water is at least one of distilled water, deionized water, and industrial soft water. Even more preferably, the aqueous light-duty liquid detergent formulation of the present invention comprises 25 to 99 wt % (preferably 50 to 98 wt %, even more preferably 60 to 97 wt %, and most preferably 65 to 80 wt %) of water based on the weight of the aqueous light-duty liquid detergent formulation, and the water is distilled and deionized. Most preferably, the aqueous light-duty liquid detergent formulation of the present invention comprises 25 to 99 wt. % (more preferably, 50 to 98 wt. %, even more preferably, 60 to 97 wt. %, and most preferably, 65 to 80 wt. %) water, based on the weight of the aqueous light-duty liquid detergent formulation, and the water is distilled, deionized, and industrial-soft to avoid the introduction of undesirable metal ions into the aqueous light-duty liquid detergent formulation.

[0026] Preferably, the aqueous light-duty liquid detergent formulation of the present invention comprises 0.01 to 15 wt % (more preferably 0.1 to 10 wt %, even more preferably 0.5 to 7.5 wt %, and most preferably 1 to 5 wt %) of a zwitterionic surfactant based on the weight of the aqueous light-duty liquid detergent formulation. Preferably, the aqueous light-duty liquid detergent formulation of the present invention comprises 0.01 to 15 wt % (more preferably 0.1 to 10 wt %, even more preferably 0.5 to 7.5 wt %, and most preferably 1 to 5 wt %) of a zwitterionic surfactant based on the weight of the aqueous light-duty liquid detergent formulation, the zwitterionic surfactant being selected from the group consisting of betaine, amine oxide, alkylamidoalkylamine, alkyl-substituted amine oxide, acylated amino acid, derivatives of aliphatic quaternary ammonium compounds, and mixtures thereof. More preferably, the aqueous light-duty liquid detergent formulations of the present invention comprise 0.01 to 15 wt. % (more preferably, 0.1 to 10 wt. %, even more preferably, 0.5 to 7.5 wt. %, and most preferably, 1 to 5 wt. %) of a zwitterionic surfactant based on the weight of the aqueous light-duty liquid detergent formulation, the zwitterionic surfactant comprising an amine oxide having a long chain group having 8 to 18 carbon atoms. Even more preferably, the aqueous light-duty liquid detergent formulations of the present invention comprise 0.01 to 15 wt. % (preferably, 0.1 to 10 wt. %, even more preferably, 0.5 to 7.5 wt. %, and most preferably, 1 to 5 wt. %) of a zwitterionic surfactant based on the weight of the aqueous light-duty liquid detergent formulation, the zwitterionic surfactant comprising an amine oxide having a long chain group having 8 to 18 carbon atoms. 8~18 Still more preferably, the aqueous light-duty liquid detergent formulation of the present invention comprises 0.01 to 15 wt. % (preferably 0.1 to 10 wt. %, even more preferably 0.5 to 7.5 wt. %, and most preferably 1 to 5 wt. %) of a zwitterionic surfactant, based on the weight of the aqueous light-duty liquid detergent formulation, the zwitterionic surfactant being C 10~14Most preferably, the aqueous light-duty liquid detergent formulation of the present invention comprises 0.01 to 15 wt % (more preferably, 0.1 to 10 wt %, even more preferably, 0.5 to 7.5 wt %, and most preferably, 1 to 5 wt %) of a zwitterionic surfactant based on the weight of the aqueous light-duty liquid detergent formulation, and the zwitterionic surfactant comprises (preferably is) lauryl dimethyl amine oxide.

[0027] Preferably, the aqueous light-duty liquid detergent formulation of the present invention comprises 0.01 to 35 wt. % (preferably 0.1 to 20 wt. %, more preferably 1 to 15 wt. %, most preferably 2.5 to 10 wt. %) of an alcohol ethoxy sulfate surfactant of formula I, based on the weight of the aqueous light-duty liquid detergent formulation;

[0028] [ka] In the formula, each R 1 and R 2 independently, C 1~16 Alkyl groups (preferably C 1~15 alkyl groups, more preferably C 1~14 Alkyl groups, most preferably linear C 1~13 ) and R 1 and R 2 The total number of carbon atoms in R is 7 to 17 (preferably 10 to 16, more preferably 11 to 15, and most preferably 12 to 14). 1 and R 2 is a linear alkyl group), M + is -SO3 in formula I - a cation that balances the negative charge of the anion (preferably M +is a cation selected from the group consisting of nitrogen-containing cations (e.g., ammonium cations), metal cations (e.g., alkali metal cations, alkaline earth metal cations), boron-containing cations, and phosphorus-containing cations, more preferably ammonium cations, alkali metal cations, and alkaline earth metal cations, even more preferably ammonium cations, sodium cations, and calcium cations, most preferably sodium cations), and n is (preferably 13 1 in 95-100 mol % (preferably, 96-100 mol %, more preferably, 97-100 mol %, and most preferably, 97.5-100 mol %) of the alcohol ethoxy sulfate surfactant of Formula I as determined using C nuclear magnetic resonance characterization.

[0029] Preferably, the alcohol ethoxy sulfate surfactant of Formula I contains less than 9 ppm (preferably less than 8 ppm, more preferably less than 7 ppm, even more preferably less than 6 ppm, even more preferably less than 5 ppm, even more preferably less than 4 ppm, even more preferably less than 3 ppm, even more preferably less than 2 ppm, even more preferably less than 1 ppm, even more preferably less than 0.25 ppm, and most preferably below the detectable limit) of 1,4-dioxane, based on the solids weight of the alcohol ethoxy sulfate surfactant of Formula I (preferably, the 1,4-dioxane content is measured by liquid injection low-temperature gas chromatography-mass spectrometry for the organic layer and by liquid chromatography-mass spectrometry for the aqueous layer).

[0030] Preferably, the alcohol ethoxy sulfate surfactant of formula I contains less than 2 wt. % (preferably less than 1.75 wt. %, more preferably less than 1.5 wt. %, even more preferably less than 1.25 wt. %, even more preferably less than 1.1 wt. %, and most preferably ≦1 wt. %) of the alcohol sulfate surfactant of formula II, based on the solids weight of the alcohol ethoxy sulfate surfactant of formula I;

[0031] [ka] In the formula, each R 3 and R 4 independently, C 1~16 Alkyl groups (preferably C 1~15 alkyl groups, more preferably C 1~14 Alkyl groups, most preferably linear C 1~13 ) and R 1 and R 2 The total number of carbon atoms in R is 7 to 17 (preferably 10 to 16, more preferably 11 to 15, and most preferably 12 to 14). 1 and R 2 is a straight-chain alkyl group), and A + is -SO3 in formula II - A cation that balances the negative charge of the anion (preferably A + is a cation selected from the group consisting of nitrogen-containing cations (e.g., ammonium cations), metal cations (e.g., alkali metal cations, alkaline earth metal cations), boron-containing cations, and phosphorus-containing cations, more preferably ammonium cations, alkali metal cations, and alkaline earth metal cations, even more preferably ammonium cations, sodium cations, and calcium cations, and most preferably sodium cations).

[0032] Preferably, the aqueous light-duty liquid detergent formulations of the present invention comprise an alcohol ethoxy sulfate surfactant of formula I as described above, which has increased thermal stability. More preferably, the aqueous light-duty liquid detergent formulations of the present invention comprise an alcohol ethoxy sulfate surfactant of formula I as described above, which has increased thermal stability. The term "enhanced thermal stability" as used herein and in the appended claims means that the alcohol ethoxy sulfate surfactant of Formula I, when heated to 110°C, contains less than 9 ppm (preferably less than 8 ppm, more preferably less than 7 ppm, even more preferably less than 6 ppm, also more preferably less than 5 ppm, even more preferably less than 4 ppm, even more preferably less than 3 ppm, even more preferably less than 2 ppm, even more preferably less than 1 ppm, and most preferably less than 0.5 ppm) of 1,4-dioxane, based on the solids weight of the alcohol ethoxy sulfate surfactant of Formula I (preferably, the 1,4-dioxane content is measured by liquid injection low-temperature gas chromatography-mass spectrometry for the organic layer and by liquid chromatography-mass spectrometry for the aqueous layer). As used herein and in the appended claims, the term "enhanced thermal stability" means that the alcohol ethoxy sulfate surfactant of Formula I, when heated to 280°C, contains less than 10 ppm 1,4-dioxane, based on the solids weight of the alcohol ethoxy sulfate surfactant of Formula I (preferably, the 1,4-dioxane content is measured by liquid injection gas chromatography-mass spectrometry for the organic layer and by liquid chromatography-mass spectrometry for the aqueous layer).

[0033] Preferably, the aqueous light-duty liquid detergent formulation of the present invention further comprises 0 to 10 wt % (preferably 0.1 to 10 wt %, more preferably 0.5 to 7.5 wt %, most preferably 1 to 5 wt %) of an organic solvent based on the weight of the aqueous light-duty liquid detergent formulation. Preferably, the aqueous light-duty liquid detergent formulation of the present invention further comprises 0 to 10 wt % (preferably 0.1 to 10 wt %, more preferably 0.5 to 7.5 wt %, most preferably 1 to 5 wt %) of an organic solvent based on the weight of the aqueous light-duty liquid detergent formulation, the organic solvent being miscible with water. Most preferably, the aqueous light-duty liquid detergent formulation of the present invention further comprises 0 to 10 wt % (preferably 0.1 to 10 wt %, more preferably 0.5 to 7.5 wt %, most preferably 1 to 5 wt %) of an organic solvent based on the weight of the aqueous light-duty liquid detergent formulation, the organic solvent being an aliphatic alcohol (e.g., C 1~6 Alkanol, C 1~6alkyl diols), monoalkylene glycol ethers (e.g., ethylene glycol propyl ether, ethylene glycol n-butyl ether, ethylene glycol t-butyl ether, propylene glycol propyl ether, propylene glycol n-butyl ether, propylene glycol t-butyl ether, propylene glycol methyl ether acetate, propylene glycol diacetate), polyalkylene glycol ethers (e.g., diethylene glycol ethyl ether, diethylene glycol propyl ether, diethylene glycol n-butyl ether, diethylene glycol t-butyl ether, diethylene glycol hexyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol propyl ether, dipropylene glycol n-butyl ether, dipropylene glycol t-butyl ether, dipropylene glycol phenyl ether, dipropylene glycol methyl ether acetate, tripropylene glycol methyl ether, tripropylene glycol ethyl ether, tripropylene glycol propyl ether, tripropylene glycol n-butyl ether, tripropylene glycol t-butyl ether), and mixtures thereof. Even more preferably, the aqueous light-duty liquid detergent formulation of the present invention further comprises 0 to 10 wt % (preferably 0.1 to 10 wt %, more preferably 0.5 to 7.5 wt %, and most preferably 1 to 5 wt %) of an organic solvent, based on the weight of the aqueous light-duty liquid detergent formulation, the organic solvent being selected from the group consisting of isopropanol, ethanol, 2-(2-butoxyethoxy)ethanol, ethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol propyl ether, propylene glycol t-butyl ether, dipropylene glycol methyl ether, dipropylene glycol propyl ether, dipropylene glycol n-butyl ether, and mixtures thereof.Even more preferably, the aqueous light-duty liquid detergent formulation of the present invention further comprises 0 to 10 wt % (preferably 0.1 to 10 wt %, more preferably 0.5 to 7.5 wt %, most preferably 1 to 5 wt %) of an organic solvent based on the weight of the aqueous light-duty liquid detergent formulation, the organic solvent comprising ethanol. Most preferably, the aqueous light-duty liquid detergent formulation of the present invention further comprises 0 to 10 wt % (preferably 0.1 to 10 wt %, more preferably 0.5 to 7.5 wt %, most preferably 1 to 5 wt %) of an organic solvent based on the weight of the aqueous light-duty liquid detergent formulation, the organic solvent being ethanol.

[0034] Preferably, the aqueous light-duty liquid detergent formulation of the present invention further comprises 0 to 10 wt % (preferably 0.1 to 10 wt %, more preferably 0.5 to 7.5 wt %, most preferably 1 to 5 wt %) of a hydrotrope based on the weight of the aqueous light-duty liquid detergent formulation. Most preferably, the aqueous light-duty liquid detergent formulation of the present invention further comprises 0 to 10 wt % (preferably 0.1 to 10 wt %, more preferably 0.5 to 7.5 wt %, most preferably 1 to 5 wt %) of a hydrotrope based on the weight of the aqueous light-duty liquid detergent formulation, the hydrotrope being selected from the group consisting of calcium, sodium, potassium, ammonium, and alkanolammonium salts of xylene sulfonic acid, toluene sulfonic acid, ethylbenzene sulfonic acid, cumene sulfonic acid, and mixtures thereof. Even more preferably, the aqueous light-duty liquid detergent formulation of the present invention further comprises 0 to 10 wt % (preferably 0.1 to 10 wt %, more preferably 0.5 to 7.5 wt %, and most preferably 1 to 5 wt %) of a hydrotrope based on the weight of the aqueous light-duty liquid detergent formulation, the hydrotrope being selected from the group consisting of sodium toluene sulfonate, potassium toluene sulfonate, sodium xylene sulfonate, ammonium xylene sulfonate, potassium xylene sulfonate, calcium xylene sulfonate, sodium cumene sulfonate, ammonium cumene sulfonate, and mixtures thereof. Even more preferably, the aqueous light-duty liquid detergent formulation of the present invention further comprises 0 to 10 wt % (preferably 0.1 to 10 wt %, more preferably 0.5 to 7.5 wt %, and most preferably 1 to 5 wt %) of a hydrotrope based on the weight of the aqueous light-duty liquid detergent formulation, the hydrotrope comprising sodium xylene sulfonate. Most preferably, the aqueous light-duty liquid detergent formulation of the present invention further comprises 0 to 10 wt. % (preferably 0.1 to 10 wt. %, more preferably 0.5 to 7.5 wt. %, most preferably 1 to 5 wt. %) of a hydrotrope, based on the weight of the aqueous light-duty liquid detergent formulation, and the hydrotrope is sodium xylene sulfonate.

[0035] Preferably, the aqueous light-duty liquid detergent formulation of the present invention further comprises an additive selected from the group consisting of salts, builders, enzymes, corrosion inhibitors, acids, bleaching agents, abrasives, antibacterial agents, chelating agents, additional surfactants, pH adjusters, buffers, and mixtures thereof.

[0036] Preferably, the method for hand washing an article of the present invention comprises providing an article, wherein the article is selected from the group consisting of at least one of dishes, glassware, silverware, pots, pans, and delicate garments (preferably, the article is selected from the group consisting of at least one of dishes, glassware, silverware, pots, and pans; more preferably, the article is selected from the group consisting of at least one of dishes, glassware, and silverware), providing an aqueous light-duty liquid detergent formulation of the present invention, manually contacting the article with the aqueous light-duty liquid detergent formulation, and rinsing the aqueous light-duty liquid detergent formulation from the article.

[0037] Some embodiments of the present invention will now be described in detail in the following examples.

[0038] [Table 1]

[0039] Synthesis S1:C 12 EO A 3-liter (L) three-necked glass round-bottom flask equipped with a centrally stirred overhead, a reflux condenser, and a heating jacket was used for the catalytic etherification of 1-dodecene and monoethylene glycol. A pitch-blade impeller was used for stirring to ensure good mixing. A reaction mixture of 551.7 grams (g) of ethylene glycol and 505.8 g of 1-dodecene was prepared and charged to a reactor at 23°C along with 61 g of catalyst in powder form. The impeller stirring speed was set at 400 revolutions per minute (rpm). The reactor was heated to 135°C over 30 minutes, held at 135°C for 18 hours, and then cooled to 23°C by turning off the heater. The reaction mixture was separated into a monoethylene glycol and catalyst phase and an olefin phase using a separatory funnel.

[0040] The distillation apparatus was constructed using a 1-liter round-bottom flask connected to a short-path distillation head with a thermometer adapter and a condenser with a vacuum adapter at the outlet. The distillation flask was heated in an aluminum block with an IKA heated stir plate. The combined olefin phase was charged to the distillation pot, and then stirring and vacuum were applied. Significant boiling was observed, but no condensate was observed or collected. The temperature of the heating block was increased to 75°C, and unreacted dodecane was collected at distillation head temperatures of 25°C to 50°C and pressures of 13.3 to 40 Pascals (Pa). The heating block temperature was gradually increased to 140°C, and an intermediate fraction containing both monoether alcohol ethoxylate and dodecene was collected, while the head temperature was increased from 50°C to 75°C at a pressure of 13 Pa. 12 EO was collected at a head temperature of 70°C to 115°C and a pressure of 6 Pa to 33 Pa. The heating block temperature was gradually increased to 200°C, an intermediate fraction containing both monoether alcohol ethoxylates and diethers was collected, and the head temperature was increased from 115°C to 130°C at a pressure of 6 Pa. The distillation was stopped, and the remaining diethers in the pot were collected. 12 The EO was then subjected to a sulfation process to produce sulfate anionic surfactants.

[0041] Synthesis S2:C 14 EO A 300 mL Parr reactor with a heating jacket and controls was used for the catalytic etherification of 1-tetradecene and monoethylene glycol. A pitched blade impeller was used for agitation to ensure good mixing.

[0042] A reaction mixture of 100.0 g of monoethylene glycol and 100.0 g of 1-tetradecene was prepared and charged into a reactor at 23°C along with 10.0 g of powdered catalyst. The impeller agitation speed was set to at least 600 rpm. The reactor was heated to 135°C in 30 minutes, held at 135°C for 6 hours, and then cooled to room temperature by turning off the heater. The reaction mixture was separated into a monoethylene glycol and catalyst phase and an olefin phase using a separatory funnel. Fifteen batches were produced, and the olefin phase was collected and combined for distillation.

[0043] The same distillation apparatus as used in synthesis S1 was used. 14 This was used for the distillation of EO. The distillation pot was charged with the olefin phase product from a multiple batch reactor run, then agitation and vacuum were applied. Significant boiling was observed, but no condensate was observed or collected. The heating block temperature was increased to 95°C, and unreacted 1-tetradecene was collected at a distillation head temperature of 30°C to 60°C and a pressure of 27 Pa to 5 Pa. The heating block temperature was gradually increased to 170°C, and an intermediate fraction containing both the monoether and tetradecene was collected, with the head temperature increasing from 60°C to 85°C at a pressure of 7 Pa to 5 Pa. 14 EO was collected at a head temperature of 80° C. to 115° C. and a pressure of 8 Pa to 5 Pa. Distillation was stopped when no more material was distilling with the pot temperature set at 170° C.

[0044] Synthesis S3:C 12 EO Sulfate All chemical manipulations were carried out under a dry nitrogen atmosphere. Prior to the experiments, all glassware was heated in a laboratory oven to remove residual water. A 2 L three-necked round-bottom flask was charged with dichloromethane (500 mL) and C prepared according to Synthesis S1. 12 EO (40 g, 0.173 mol, 1.0 equiv.) was charged to the reaction flask. The reaction flask was equipped with an overhead mechanical stirrer, an addition funnel, and a thermocouple. Chlorosulfonic acid (12.7 mL, 0.191 mol, 1.1 equiv.) was then carefully charged to the addition funnel. The reaction flask was then submerged in an ice bath and allowed to cool to 0°C for 20 minutes. Once the reaction was cooled, chlorosulfonic acid was added dropwise to the reaction flask at a rate of approximately 1.0 mL / min over approximately 20 minutes. The reaction temperature did not exceed 5°C during the addition of the chlorosulfonic acid. After the addition, the reaction was allowed to react, and the temperature was maintained between 0 and 5°C for 3 hours. At this point, the reaction was neutralized by the slow, dropwise addition of an aqueous NaOH solution (18.0 g NaOH, 0.9 mol, in 500 mL water). The rate of addition was slow enough so that the temperature did not exceed 5°C over the course of the addition. The solution became basic after the addition of approximately 300 mL of 0.9 M NaOH solution. The dichloromethane was then carefully removed from the two-phase reaction mixture in vacuo. During the removal of the dichloromethane, copious amounts of foaming were observed. Upon removal of the dichloromethane, the remaining aqueous solution was placed in a freeze dryer to obtain the secondary alcohol ethoxylate sulfate product, C. 12 EO sulfate was obtained as an off-white solid (61.9 grams).

[0045] Synthesis S4:C 14 EO Sulfate All chemical manipulations were carried out under a dry nitrogen atmosphere. Prior to the experiments, all glassware was heated in a laboratory oven to remove residual water. A 2 L three-necked round-bottom flask was charged with dichloromethane (500 mL) and C prepared according to synthesis S2. 14EO (50 g, 0.193 mol, 1.0 equiv.) was charged to the reaction flask. The reaction flask was equipped with an overhead mechanical stirrer, an addition funnel, and a thermocouple. Chlorosulfonic acid (14.2 mL, 0.213 mol, 1.1 equiv.) was then carefully charged to the addition funnel. The reaction flask was then submerged in an ice bath and allowed to cool to 0°C for 20 minutes. Once the reaction was cooled, chlorosulfonic acid was added dropwise to the reaction flask at a rate of approximately 1.0 mL / min over approximately 20 minutes. The reaction temperature did not exceed 5°C during the addition of the chlorosulfonic acid. After the addition, the reaction was allowed to react, and the temperature was maintained between 0°C and 5°C for 3 hours. At this point, the reaction was neutralized by the slow, dropwise addition of aqueous NaOH (18.0 g, 0.9 mol in 500 mL of water). The rate of addition was slow enough so that the temperature did not exceed 5°C over the course of the addition. The solution became basic after the addition of approximately 400 mL of 0.9 M NaOH solution. The dichloromethane was then carefully removed from the two-phase reaction in vacuo. During the removal of the DCM, copious foaming was observed. Upon removal of the DCM, the remaining aqueous solution was placed on a freeze dryer to yield the secondary alcohol ethoxylate sulfate product (68.6 grams).

[0046] Synthetic S5:ALEO1 Sulfate ALEO1 sulfate was prepared from ALEO1 by the same method described in Synthesis S3.

[0047] Synthetic S6:SA3EO Sulfate SA3EO sulfate was prepared from SA3EO in the same manner as described in Synthesis S3.

[0048] EO distribution of surfactants The distribution of EO adducts in the surfactants listed in Table 1 was determined by NMR or UHPLC-MS, as noted, using the methodologies described below with the results provided in Table 1.

[0049] Nuclear Magnetic Resonance (NMR) EO Distribution Characterization The surfactant samples to be analyzed were prepared by dissolving the surfactant in deuterated dimethyl sulfoxide containing 0.025 M chromium(III) acetylacetate. The samples were then analyzed by nuclear magnetic resonance (NMR) analysis. 13 C NMR spectra were collected on a Bruker AVANCE 400 MHz spectrometer equipped with a 10 mm cryoprobe set at 25 °C using the following parameters: 90° pulse, inverse gated decoupling, 1.38 s acquisition time, and 6.4 s recycle delay. 2048 scans were collected. Data were processed with MNOVA, and chemical shifts were referenced to the solvent peak at 39.52 ppm. DEPT-135 experiments were also acquired with the same parameters, except for a 2.0 s recycle delay, and 2048 scans were collected. The ratios of the different EO adducts were calculated by integrating and comparing the intensities of the ethylene oxide alcohol end groups at approximately 60-61 ppm, the ethylene oxide backbone groups at approximately 69-70 ppm, the ethylene oxide end group ether peak at approximately 71-72 ppm, the unreacted primary alcohol peak at approximately 60-61 ppm, and the unreacted secondary alcohol peak at approximately 65-66 ppm.

[0050] Sodium Lauryl Ether Sulfate Analysis by UHPLC-MS Ultra high performance liquid chromatography-mass spectrometry (UHPLC-MS) conditions:

[0051] [Table 2]

[0052] Procedure: Commercial surfactant-containing compositions were analyzed by ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) with electrospray ionization (ESI). For analysis, stock solutions were prepared at a concentration of 25 ppm in a 50 / 50 mixture of methanol / water. Alcohol ethoxylate samples were diluted 1:100 in duplicate with 50 / 50 methanol / water and vortexed for several seconds. They were then diluted 1:10 in 50 / 50 methanol / water to obtain a final dilution of 1:1,000. Ethal® LA-4 was the standard used for commercially available 1-molar sodium laureth sulfate, and Ethal® LA-7 was the standard used for commercially available 3-molar sodium laureth sulfate. Calibration standards were prepared at 10 ppm, 5 ppm, 2 ppm, and 1 ppm in 50 / 50 methanol / water.

[0053] Alkyl sulfates were diluted from a 1:1,000 preparation into 50 / 50 methanol / water to give a final solution of 1:20,000. POLYSTEP® BN-5 was used as the standard for alkyl sulfate analysis. Standards were prepared at concentrations of 5 ppm, 2 ppm, 1 ppm, and 0.5 ppm in 50 / 50 methanol / water.

[0054] Samples were analyzed using a Waters ACQUITY® UPLC system equipped with a Waters BEH C18 1.7 μm 1 × 50 mm column. Mass spectrometry was performed using a Waters LCT Premier TOF mass spectrometer equipped with ESI. Measurements were performed in both positive and negative ion modes. Each sample preparation was injected three times for analysis. The ratios of the different EO adducts were calculated by peak area and are reported in Table 1.

[0055] [Table 3]

[0056] At least 95 mol % of the oligomers in the products of Syntheses S4 and S5 had an n of 1, and not more than 5 mol % of the oligomers had an n of 2 or greater. Specifically, ≥ 98 mol % of the oligomers in the products of Syntheses S4 and S5 had an n of 1, and not more than 2 mol % of the oligomers had an n of 2 or greater.

[0057] 1,4-dioxane content of surfactants The 1,4-dioxane content in the surfactants listed in Table 2 was determined by liquid injection low-temperature gas chromatography-mass spectrometry (GC-MS) for the organic layer and liquid chromatography-mass spectrometry (LC-MS) for the aqueous layer, as noted, using the methodology described below with the results provided in Table 2.

[0058] Gas chromatography-mass spectrometry (GC-MS) conditions for measuring 1,4-dioxane in the organic layer:

[0059] [Table 4]

[0060] Standards were prepared by adding dioxane to tetrahydrofuran ("THF") and diluting from 0.1 to 100 ppm.

[0061] Samples were prepared by mixing 3.3 g of the organic (DCM) layer of the crude process mixture with 6.7 g of THF, then shaking the solution for approximately 20 minutes. The solids were then centrifuged to the bottom, and the supernatant was placed in an autosampler vial. Spiked samples were prepared by adding dioxane standards in THF to separate samples at 5-10 ppm.

[0062] Liquid chromatography-mass spectrometry (LC-MS) conditions for measuring the 1,4-dioxane content of the aqueous layer:

[0063] [Table 5]

[0064] Samples were injected neat or diluted 1:4 with water. Standards were prepared by preparing a dioxane in THF stock solution and diluting with water to 0.1-100 ppm.

[0065] Calculation of dioxane content for solids The ppm of dioxane content relative to the solid content in the sample is calculated according to Equation 1.

[0066]

number

[0067] [Table 6]

[0068] Gas chromatography results for SA3EO Sulfate surfactant showed secondary alcohols with an average of 3 moles of ethylene oxide per molecule containing 2 ppm of 1,4-dioxane in the organic phase at 110°C, indicating the potential of structures with n > 2 to produce 1,4-dioxane. Interestingly, when the inlet temperature was increased to 280°C, the dioxane content of SA3EO Sulfate increased from 2 ppm to 1471 ppm of 1,4-dioxane in the organic phase. This result indicates that while sulfated surfactants with n > 2 can generate observable 1,4-dioxane at 110°C, such surfactants may be unstable at temperatures as high as 280°C, which can result in significant 1,4-dioxane formation. Similar to SA3EO Sulfate, gas chromatography results for ALEO1 Sulfate surfactant show the formation of 1,4-dioxane at greater than 9 ppm based on the solid at 110°C. Furthermore, ALEO1 Sulfate surfactant also showed significant production of 1,4-dioxane (259 ppm) at 280°C, indicating that ALEO1 Sulfate surfactant lacks stability at elevated temperatures. The C surfactants of the present invention, in which 95 mol% or more have n=1 and 5 mol% or less have n≧2, 12 EO sulfate surfactants exhibit low 1,4-dioxane content. Surprisingly, the C 12 The EO sulfate surfactants also exhibited extremely low 1,4-dioxane content, below the limit of detection (LOD) of the GC and LC methods. Using the LOD as a measure, this was 12 It shows that the dioxane content for EO sulfate is less than 1.6 ppm on a solid basis at 110° C. Interestingly, the C 12 When the inlet temperature of EO sulfate was increased to 280°C, the 1,4-dioxane content of the material was still less than 1 ppm (i.e., 0.58 ppm), which is consistent with the C 12 EO sulfate shows increased thermal stability compared to the comparative material.

[0069] Comparative Examples CF1 to CF4 and Examples F1 to F5 Light-duty liquid detergent formulation The light-duty liquid detergent formulations of Comparative Examples CF1-CF4 and Examples F1-F5 were prepared by mixing together the ingredients in the weight proportions noted in Table 3, adjusted to pH 8 (if necessary) with sodium hydroxide.

[0070] [Table 7]

[0071] Performance Test Flash foam (handshake method) The flash foam performance of the light-duty liquid detergent formulations of Comparative Examples CF1-CF4 and Examples F1-F5 was evaluated by adding 10 g of 15 dH hard water (3:1 Ca) to a glass vial (30 mL, 25 mm diameter x 95 mm height). 2+ :Mg 2+ The detergent compositions were evaluated by loading 0.1% by weight of a light-duty liquid detergent formulation into a 1000 ml (1000 ml) jar. The formulations were shaken up and down for 20 seconds at a rate of approximately 2 shakes per second. The height of the foam generated from the solution was measured with a ruler after allowing it to stand for 1, 3, or 5 minutes. The results are provided in Tables 4 and 5.

[0072] [Table 8]

[0073] [Table 9]

[0074] Foam performance (stirring method) The foam performance of the light-duty liquid detergent formulations of Comparative Examples CF1-CF4 and Examples F1-F2 was measured in 15 dH hard water (3:1 Ca 2+ :Mg 2+The foam analysis was evaluated by preparing a 0.1 wt. % test solution of the light-duty liquid detergent formulation in 100 mL of water. A 100 mL portion of the test solution was transferred to the test cylinder of a Kruss Dynamic Foam Analyzer (DFA100) Instrument. Foam was generated for 80 seconds with a 5-second oscillation period at a mixing speed of 4,000 rpm. After mixing, foam height and bubble count were continuously monitored for 5 minutes. The results of the foam analysis are provided in Table 6.

[0075] [Table 10]

[0076] viscosity The viscosities of the light-duty liquid detergent formulations of Comparative Example CF2 and Examples F1-F5 were measured on a Hamilton MICROLAB STAR liquid handler (Hamilton Robotics) using a Total Aspiration and Dispense Monitoring (TADM) system. The results are provided in Table 7.

[0077] [Table 11]

[0078] Soap Foam Mileage The suds mileage performance of the light-duty liquid detergent formulations of Comparative Examples CF1-CF2 and Examples F1-F5 was evaluated using the following procedure: A test vial (30 mL, 25 mm diameter x 95 mm height) was filled with 10 g of 15 dH hard water (3:1 Ca 2+ :Mg 2+A 0.1 wt% solution of the light-duty liquid detergent formulation in HCl and 0.012 g of olive oil were added to form a test solution. The test solution was then mixed in a closed test vial at 500 rpm for 2 minutes at room temperature in an Electrothermal RS-5000 reaction station using a PTFE-coated magnetic stir bar. The test vial was then shaken up and down for 20 seconds at a rate of two up and down movements per second. The foam height was then immediately measured using a ruler (initial). The test solution was then stirred at 500 rpm on the reaction station at 46°C for 1 hour. The test vial was then shaken up and down for 20 seconds at a rate of two up and down movements per second. The foam height was then measured using a ruler (H1). Finally, the test solution was stirred at 500 rpm on the reaction station at 46°C for an additional 30 minutes. The test vial was then shaken up and down for 20 seconds at a rate of two up and down movements per second. The foam height was then measured with a ruler (H2). Lather retention is equal to (H2 / H1)*100. The results of the first olive oil dosage are provided in Table 8. A second set of test vials was prepared containing an additional 0.012g dose of olive oil (0.014g total olive oil) and the foam procedure was repeated. The results of the second olive oil dosage are provided in Table 9.

[0079] [Table 12]

[0080] [Table 13]

[0081] Oil stain cleaning The oily soil cleaning performance of the light-duty liquid detergent formulations of Comparative Examples CF1-CF2 and Examples F1-F2 was determined using tiles pre-soiled with red palm oil (DM-97, Center for Test Materials, Netherlands). The test solution was a 15 dH hard water (3:1 Ca 2+ :Mg 2+The test solutions were prepared as 1.0 wt. % solutions of the light-duty liquid detergent formulation in 100 mL of water. The test solutions were heated to 35°C. A portion (2 mL) of the heated test solution was placed on a small area (approximately 1.5 cm x 4.5 cm) of a pre-soiled tile. The treated tile was placed in an oven at 35°C and allowed to soak for 15 minutes. The tile was then removed from the oven. The test solution was quickly removed and the tile was rinsed twice with deionized water. The percent cleaning was determined by measuring the color change of the tile before and after cleaning. The results are provided in Table 10.

[0082] [Table 14]

Claims

1. 1. An aqueous light-duty liquid detergent formulation comprising: Water and a zwitterionic surfactant; an alcohol ethoxy sulfate surfactant of formula I, 【Chemical 1】 In the formula, each R １ and R ２ But independently, C １～１６ is an alkyl group, and R １ and R ２ The total number of carbon atoms in M ​​is 7 to 17, ＋ is —SO of Formula I ３ － An aqueous light-duty liquid detergent formulation in which n is 1 in 95-100 mol % of the alcohol ethoxy sulfate surfactant of formula I, which is a cation that balances the negative charge of the anion.

2. 2. The aqueous light-duty liquid detergent formulation of claim 1, wherein said alcohol ethoxy sulfate surfactant of Formula I contains less than 9 ppm 1,4-dioxane.

3. 3. The aqueous light-duty liquid detergent formulation of claim 2, wherein said alcohol ethoxy sulfate surfactant of formula I has increased thermal stability (preferably enhanced thermal stability).

4. the aqueous light-duty liquid detergent formulation contains less than 1 wt. % of an alcohol sulfate surfactant of formula II, based on the solids weight of the aqueous light-duty liquid detergent formulation; 【Chemistry 2】 In the formula, each R ３ and R ４ But independently, C １～１６ is an alkyl group, and R ３ and R ４ The total number of carbon atoms in A is 7 to 17, ＋ is —SO in Formula II ３ － 3. The aqueous light-duty liquid detergent formulation of claim 2, wherein the anion is a cation that balances the negative charge on the anion.

5. 5. The aqueous light-duty liquid detergent formulation of claim 4, further comprising an organic solvent.

6. 6. The aqueous light-duty liquid detergent formulation of claim 5, wherein the zwitterionic surfactant is an alkyl-substituted amine oxide.

7. The zwitterionic surfactant is C １０～１４ 6. The aqueous light-duty liquid detergent formulation of claim 5, wherein the alkyl dimethyl amine oxide is an alkyl dimethyl amine oxide.

8. 10. The aqueous light-duty liquid detergent formulation of claim 1 further comprising a hydrotrope.

9. The aqueous cleaning formulation comprises: 50 to 97 weight percent water, based on the weight of the aqueous light-duty liquid detergent formulation; 0.1 to 10 wt. % of said organic solvent, based on the weight of said aqueous light-duty liquid detergent formulation; 0.1 to 10 wt. % of said zwitterionic surfactant, based on the weight of said aqueous light-duty liquid detergent formulation; 8. The aqueous light-duty liquid detergent formulation of claim 7, comprising: 0.1 to 20% by weight of said alcohol ethoxy sulfate surfactant of formula I, based on the weight of said aqueous light-duty liquid detergent formulation.

10. 1. A method for hand washing an item, comprising: providing an article, said article being selected from the group consisting of at least one of dishes, glassware, silverware, pots and pans, and delicate clothing; Providing an aqueous light-duty liquid detergent formulation according to claim 1; manually contacting the article with the aqueous light-duty liquid detergent formulation; and rinsing said aqueous light-duty liquid detergent formulation from said article.

Images