EP4780931A1 - Concentrated laundry detergent composition - Google Patents

Abstract

A concentrated laundry detergent composition is provided including: a solvent system, wherein the solvent system is a mixture of water and a nonaqueous solvent; a cleaning surfactant; wherein the cleaning surfactant comprises a blend of a nonionic surfactant; an anionic alcohol ethoxysulfate surfactant of formula (I), (I), wherein each R1 and R2 is independently a C1‑16 alkyl group; wherein the sum of the carbon atoms in R1 and R2 is 7-17; wherein M+ is a cation balancing the negative charge of the -SO3- anion of formula I; and wherein n is 1 in 95-100 mol% of the anionic alcohol ethoxysulfate surfactant of formula I; wherein the concentrated laundry detergent composition comprises <10 wt%, based on weight of the concentrated laundry detergent composition, of water.

Description

CONCENTRATED LAUNDRY DETERGENT COMPOSITION

[0001] The present invention relates to a concentrated laundry detergent composition. In particular, the present invention relates to a concentrated laundry detergent composition, comprising: a solvent system, wherein the solvent system is a mixture of water and a nonaqueous solvent; a cleaning surfactant; wherein the cleaning surfactant comprises a blend of a nonionic surfactant and an anionic alcohol ethoxysulfate surfactant of formula I wherein each R¹ and R² is independently a C1-16 alkyl group; wherein the sum of the carbon atoms in R¹ and R² is 7 to 17; wherein M⁺ is a cation balancing the negative charge of the -SO₃- anion of formula I; and wherein n is 1 in 95 to 100 mol% of the anionic alcohol ethoxysulfate surfactant of formula I; wherein the concentrated laundry detergent composition comprises < 15 wt%, based on weight of the concentrated laundry detergent composition, of water.

[0002] Aqueous laundry detergent formulations frequently include alkyl ethoxy sulfate anionic surfactants (e.g., alcohol ethoxysulfate surfactants). However, such surfactants have been associated with undesirable 1,4 dioxane content. Regulators are increasingly restricting the amount of 1,4 dioxane that may be present in consumer products. For example, New York State has banned all but trace amounts of 1,4 dioxane in cleaning products. Typically, a consumer product must contain less than 10 parts per million by weight (ppm) of 1,4 dioxane to be compliant with the regulations. One contributor of the unintended incorporation of 1,4 dioxane in consumer products can be the inclusion of alkyl ethoxy sulfate anionic surfactants. [0003] Inclusion of 1,4 dioxane in conventional AES surfactants is believed to occur at multiple points in time. A first point of 1,4 dioxane generation in conventional AES surfactants is believed to occur during the sulfation process of alcohol ethoxylates to make alcohol ethoxy sulfates. The alcohol ethoxylate intermediates for the production of conventional alcohol ethoxy sulfate surfactants are made via ethoxylation (i.e., the reaction of an alcohol with ethylene oxide) that typically results in a distribution of alcohol ethoxylate oligomers. It is believed that under the sulfation process conditions during the manufacture of conventional AES surfactants, 1,4 dioxane can form. A second point of 1,4 dioxane generation in association with conventional AES surfactants is believed to occur during handling and processing of the conventional AES surfactants. Handling and processing of conventional AES surfactants often involves acidic conditions at ambient, or elevated, temperature. Prolonged exposure to acidic environments for conventional AES surfactants and their alcohol ethoxylate precursors may result in the formation of 1,4 dioxane. Further, exposure to elevated temperatures (e.g., up to 280 °C) during processing, storage and/or handling may result in the decomposition of conventional AES surfactants resulting in the formation of dioxane.

[0004] Traditionally, 1,4 dioxane content in conventional AES surfactants and products incorporating such surfactants has been addressed by the use of stripping techniques. For example, where 1,4 dioxane concentrations are above a target threshold, a stripping process is employed to remove excess 1,4 dioxane from the conventional AES surfactants or product incorporating same. The stripping process is not only expensive and time consuming, but also is not a guarantee to meet the increasingly stringent regulatory requirements. Further, as 1,4 dioxane may form over time as a response to how the conventional AES surfactant or product is handled and further processed, any previously applied stripping techniques may be nullified by the generation of new 1,4 dioxane. As such, ensuring that a product comprising an AES surfactant is compliant with the appropriate regulations by the time it is sold to an end consumer is a difficult challenge.

[0005] Also, while standard (non-concentrated) liquid laundry detergents remain dominant in many markets, concentrated laundry detergent formulations are becoming more prevalent for use in both consumer and institutional cleaning applications. Accordingly, there remains a need for concentrated laundry detergent compositions having an anionic alcohol ethoxysulfate surfactant that resists forming 1,4 dioxane both during the sulfation process to form the surfactant and subsequently when the anionic alcohol ethoxysulfate surfactant is exposed to elevated temperatures of up to 280 °C.

[0006] The present invention provides a concentrated laundry detergent composition, comprising: a solvent system, wherein the solvent system is a mixture of water and a nonaqueous solvent; a cleaning surfactant; wherein the cleaning surfactant comprises a blend of a nonionic surfactant; and an anionic alcohol ethoxysulfate surfactant of formula I wherein each R¹ and R² is independently a C_1-16 alkyl group; wherein the sum of the carbon atoms in R¹ and R² is 7 to 17; wherein M⁺ is a cation balancing the negative charge of the -SO₃- anion of formula I; and wherein n is 1 in 95 to 100 mol% of the anionic alcohol ethoxysulfate surfactant of formula I; wherein the concentrated laundry detergent composition comprises < 15 wt%, based on weight of the concentrated laundry detergent composition, of water.

[0007] The present invention provides a concentrated laundry detergent composition, comprising: a solvent system, wherein the solvent system is a mixture of water and a nonaqueous solvent; a fatty acid; a neutralizing agent and a cleaning surfactant; wherein the cleaning surfactant comprises a blend of a nonionic surfactant; an anionic alcohol ethoxysulfate surfactant of formula I wherein each R¹ and R² is independently a C_1-16 alkyl group; wherein the sum of the carbon atoms in R¹ and R² is 7 to 17; wherein M⁺ is a cation balancing the negative charge of the -SO₃- anion of formula I; and wherein n is 1 in 95 to 100 mol% of the anionic alcohol ethoxysulfate surfactant of formula I; wherein the concentrated laundry detergent composition comprises 1 to < 10 wt%, based on weight of the concentrated laundry detergent composition, of water; and an additional anionic surfactant.

[0008] The present invention provides a method of washing a soiled cotton article, comprising: providing a soiled cotton article; providing a laundry detergent composition according to the present invention; providing a wash water; and applying the wash water and the laundry detergent composition to the soiled cotton article to provide a cleaned cotton article.

DETAILED DESCRIPTION

[0009] We have surprisingly found that anionic alcohol ethoxysulfate surfactant of formula I; wherein each R¹ and R² is independently a C_1-16 alkyl group; wherein the sum of the carbon atoms in R¹ and R² is 7 to 17; wherein M⁺ is a cation balancing the negative charge of the -SO₃- anion in formula I; and wherein n is 1 in 95 to 100 mol% of the anionic alcohol ethoxy sulfate surfactant of formula I resists forming 1,4 dioxane both during the sulfation process to form the anionic alcohol ethoxysulfate surfactant of formula I and subsequently when the anionic alcohol ethoxysulfate surfactant of formula I is exposed to elevated temperatures of up to 280 °C during processing, storage and/or handling.

[0010] We have also surprisingly found that anionic alcohol ethoxysulfate surfactant of formula I; wherein each R¹ and R² is independently a C_1-16 alkyl group; wherein the sum of the carbon atoms in R¹ and R² is 7 to 17; wherein M⁺ is a cation balancing the negative charge of the -SO₃- anion in formula I; and wherein n is 1 in 95 to 100 mol% of the anionic alcohol ethoxysulfate surfactant of formula I provides comparable primary cleaning performance and comparable to improved antiredeposition performance when substituted for conventional AES surfactants in aqueous laundry detergent formulations.

[0011] Unless otherwise indicated, ratios, percentages, parts, and the like are by weight (e.g., “ppm” means parts per million by weight).

[0012] The term “solids weight” as used herein and in the appended claims in reference to the concentrated laundry detergent composition and the anionic alcohol ethoxysulfate surfactant of formula I means dry weight, i.e., excluding any water that may be present. [0013] The term “solvent,” “solvents” and “solvent system” as used herein and in the appended claims in reference to the concentrated laundry detergent composition means aliquid or Equids used to dissolve or solvate other ingredients in the compositions. In some instances, ingredients may also be dispersed with the solvent/solvents/solvent system (e.g., titanium dioxide in water). In some instances, a solvent may initially exist as a solid and that is subsequently dissolved within anogher solvent (e.g., polyethylene glycol in water). As used herein, the terms “solvent,” “solvents” and “solvent system” do not encompass neutralization agents (e.g., triethanolamine, monoethanolamine and sodium hydroxide).

[0014] Preferably, the concentrated laundry detergent composition of the present invention, comprises: a solvent system (preferably, 25 to 75 wt% (more preferably, 30 to 68.5 wt%; still more preferably, 35 to 61 wt%; most preferably, 37 to 53 wt%), based on weight of the concentrated laundry detergent composition, of the solvent system), wherein the solvent system is a mixture of water and a nonaqueous solvent; optionally a fatty acid (preferably, 0 to 15 wt% (more preferably, 0.5 to 10 wt%; still more preferably, 1 to 7.5 wt%; most preferably, 2 to 4 wt%), based on weight of the concentrated laundry detergent composition, of the fatty acid); optionally a neutralizing agent (preferably, 0 to 15 wt% (more preferably, 1 to 12 wt%; still more preferably, 3 to 10 wt%; most preferably, 5 to 9 wt%), based on weight of the concentrated laundry detergent composition, of the neutralizing agent); a cleaning surfactant (preferably, 25 to 65 wt% (more preferably, 30 to 60 wt%; stiE more preferably, 35 to 55 wt%; most preferably, 40 to 50 wt%), based on weight of the concentrated laundry detergent composition, of the cleaning surfactant) wherein the cleaning surfactant comprises a blend of a nonionic surfactant (preferably, 1 to 35 wt% (more preferably, 2 to 20 wt%; still more preferably, 2 to 15 wt%; most preferably, 3 to 7 wt%), based on weight of the laundry detergent formulation, of the nonionic surfactant); an anionic alcohol ethoxysulfate surfactant of formula I (preferably, 2 to 25 wt% (more preferably, 5 to 20 wt%; still more preferably, 6 to 15 wt%; most preferably, 8 to 12 wt%), based on weight of the laundry detergent formulation, of the anionic alcohol ethoxysulfate surfactant of formula I) wherein each R¹ and R² is independently a C_1-16 alkyl group (preferably, a C_1-15 alkyl group; more preferably, a C_1-14 alkyl group; most preferably, a linear C_1-13); wherein the sum of the carbon atoms in R¹ and R² is 7 to 17 (preferably, 10 to 16; more preferably, 12 to 16; most preferably, 14 to 16)(preferably, wherein R¹ and R² are linear alkyl groups; more preferably, wherein R¹ is a methyl group and R² is a linear C10-14 alkyl group; most preferably, wherien R¹ is a methyl group and R² is a linear C12 alkyl group or a linear C14 alkyl group); wherein M⁺ is a cation balancing the negative charge of the -SO₃- anion in formula I (preferably, wherein M⁺ is a cation selected from the group consisting of a nitrogen containing cation (e.g., an ammonium cation), a metal cation (e.g., an alkali metal cation, an alkaline earth metal cation), a boron containing cation and a phosphorous containing cation; more preferably, an ammonium cation, an alkali metal cation and an alkaline earth metal cation; still more preferably, an ammonium cation, a sodium cation and a calcium cation; most preferably, a sodium cation); and wherein n is 1 in 95 to 100 mol% (preferably, 96 to 100 mol%; more preferably, 97 to 100 mol%; most preferably, 97.5 to 100 mol%) of the anionic alcohol ethoxysulfate surfactant of formula I (preferably, as determined using ¹³C nuclear magnetic resonance characterization); and optionally, an additional anionic surfactant (preferably, 0 to 62 wt% (more preferably, 0 to 53 wt%; still more preferably, 5 to 47 wt%; most preferably, 21 to 25 wt%), based on weight of the laundry detergent formulation, of the additional anionic surfactant); wherein the concentrated laundry detergent composition comprises < 15 wt% (preferably, 1 to < 10 wt%; more preferably, 2 to 9.8 wt%; most preferably, 5 to 9.75 wt%), based on weight of the concentrated laundry detergent composition, of water.

[0015] Preferably, the concentrated laundry detergent composition of the present invention, comprises 25 to 75 wt% (preferably, 30 to 68.5 wt%; more preferably, 35 to 61 wt%; most preferably, 37 to 53 wt%), based on weight of the concentrated laundry detergent composition, of the solvent system, wherein the solvent system is a mixture of water and a nonaqueous solvent; and wherein the concentrated laundry detergent composition comprises < 15 wt% (preferably, 1 to < 10 wt%; more preferably, 2 to 9.8 wt%; most preferably, 5 to 9.75 wt%), based on weight of the concentrated laundry detergent composition, of water. More preferably, the concentrated laundry detergent composition of the present invention, comprises 25 to 75 wt% (preferably, 30 to 68.5 wt%; more preferably, 35 to 61 wt%; most preferably, 37 to 53 wt%), based on weight of the concentrated laundry detergent composition, of the solvent system, wherein the solvent system is a mixture of water and a nonaqueous solvent; wherein the nonaqueous solvent is selected from the group consisting of polyols (e.g., propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, heptylene glycol, oxtylene glycol, 2-methyl-l,3-propanediol, glycerin, xylitol, sorbitol, mannitol, diethylene glycol, triethylene glycol, glycerol, erythritol, dulcitol, inositol, adonitol); ionic liquids; glycol ethers (e.g., ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, ethylene glycol monopropyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether); alkylene oxide copolymers (e.g., ethylene oxide co-propylene oxide polymers); polyethylene glycol (e.g., polyethylene glycols having a weight average molecular weight of 300 to 3,000 Daltons) and mixtures thereof; and wherein the concentrated laundry detergent composition comprises < 15 wt% (preferably, 1 to < 10 wt%; more preferably, 2 to 9.8 wt%; most preferably, 5 to 9.75 wt%), based on weight of the concentrated laundry detergent composition, of water. Still more preferably, the concentrated laundry detergent composition of the present invention, comprises 25 to 75 wt% (preferably, 30 to 68.5 wt%; more preferably, 35 to 61 wt%; most preferably, 37 to 53 wt%), based on weight of the concentrated laundry detergent composition, of the solvent system, wherein the solvent system is a mixture of water and a nonaqueous solvent; wherein the nonaqueous solvent includes a polyol selected from the group consisting of propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, heptylene glycol, oxtylene glycol, 2-methyl-l,3-propanediol, glycerin, xylitol, sorbitol, mannitol, diethylene glycol, triethylene glycol, glycerol, erythritol, dulcitol, inositol, adonitol and mixtures thereof; and wherein the concentrated laundry detergent composition comprises < 15 wt% (preferably, 1 to < 10 wt%; more preferably, 2 to 9.8 wt%; most preferably, 5 to 9.75 wt%), based on weight of the concentrated laundry detergent composition, of water. Yet more preferably, the concentrated laundry detergent composition of the present invention, comprises 25 to 75 wt% (preferably, 30 to 68.5 wt%; more preferably, 35 to 61 wt%; most preferably, 37 to 53 wt%), based on weight of the concentrated laundry detergent composition, of the solvent system, wherein the solvent system is a mixture of water and a nonaqueous solvent; wherein the nonaqueous solvent includes a mixture of propylene glycol and glycerin; and wherein the concentrated laundry detergent composition comprises < 15 wt% (preferably, 1 to < 10 wt%; more preferably, 2 to 9.8 wt%; most preferably, 5 to 9.75 wt%), based on weight of the concentrated laundry detergent composition, of water. Most preferably, the concentrated laundry detergent composition of the present invention, comprises 25 to 75 wt% (preferably, 30 to 68.5 wt%; more preferably, 35 to 61 wt%; most preferably, 37 to 53 wt%), based on weight of the concentrated laundry detergent composition, of the solvent system, wherein the solvent system is a mixture of water and a nonaqueous solvent; wherein the nonaqueous solvent is a mixture of propylene glycol and glycerin; and wherein the concentrated laundry detergent composition comprises < 15 wt% (preferably, 1 to < 10 wt%; more preferably, 2 to 9.8 wt%; most preferably, 5 to 9.75 wt%), based on weight of the concentrated laundry detergent composition, of water.

[0016] Preferably, the concentrated laundry detergent composition of the present invention, comprises 25 to 65 wt% (preferably, 30 to 60 wt%; more preferably, 35 to 55 wt%; most preferably, 40 to 50 wt%), based on weight of the concentrated laundry detergent composition, of a cleaning surfactant; wherein the cleaning surfactant comprises a blend of a nonionic surfactant and an anionic alcohol ethoxysulfate surfactant of formula I; wherein each R¹ and R² is independently a C_1-16 alkyl group (preferably, a C_1-15 alkyl group; more preferably, a C_1-14 alkyl group; most preferably, a linear C1-13); wherein the sum of the carbon atoms in R¹ and R² is 7 to 17 (preferably, 10 to 16; more preferably, 12 to 16; most preferably, 14 to 16)(preferably, wherein R¹ and R² are linear alkyl groups; more preferably, wherein R¹ is a methyl group and R² is a linear C10-14 alkyl group; most preferably, wherein R¹ is a methyl group and R² is a linear C₁₂ alkyl group or a linear C₁₄ alkyl group); wherein M⁺ is a cation balancing the negative charge of the -SO₃- anion of formula I; and wherein n is 1 in 95 to 100 mol% of the anionic alcohol ethoxy sulfate surfactant of formula I. More preferably, the concentrated laundry detergent composition of the present invention, comprises 25 to 65 wt% (preferably, 30 to 60 wt%; more preferably, 35 to 55 wt%; most preferably, 40 to 50 wt%), based on weight of the concentrated laundry detergent composition, of a cleaning surfactant; wherein the cleaning surfactant comprises a blend of a nonionic surfactant and an anionic surfactant; wherein the anionic surfactant comprises a mixture of an additional anionic surfactant and an anionic alcohol ethoxysulfate surfactant of formula I; wherein each R¹ and R² is independently a C_1-16 alkyl group (preferably, a C_1-15 alkyl group; more preferably, a C_1-14 alkyl group; most preferably, a linear C_1-13); wherein the sum of the carbon atoms in R¹ and R² is 7 to 17 (preferably, 10 to 16; more preferably, 12 to 16; most preferably, 14 to 16)(preferably, wherein R¹ and R² are linear alkyl groups; more preferably, wherein R¹ is a methyl group and R² is a linear C_10-14 alkyl group; most preferably, wherein R¹ is a methyl group and R² is a linear C₁₂ alkyl group or a linear C14 alkyl group); wherein M⁺ is a cation balancing the negative charge of the -SO₃- anion of formula I; and wherein n is 1 in 95 to 100 mol% of the anionic alcohol ethoxysulfate surfactant of formula I.

[0017] Preferably, the concentrated laundry detergent composition of the present invention, comprises 1 to 35 wt% (preferably, 2 to 20 wt%; more preferably, 2 to 15 wt%; most preferably, 3 to 7 wt%), based on weight of the concentrated laundry detergent composition, of a nonionic surfactant. More preferably, the concentrated laundry detergent composition of the present invention, comprises 1 to 35 wt% (preferably, 2 to 20 wt%; more preferably, 2 to 15 wt%; most preferably, 3 to 7 wt%), based on weight of the concentrated laundry detergent composition, of a nonionic surfactant; wherein the nonionic surfactant is selected from the group consisting of alkoxylates, polyglycol ethers, fatty alcohol polyglycol ethers, alkylphenol polyglycol ethers, end group capped polyglycol ethers, mixed ethers, hydroxy mixed ethers, fatty acid polyglycol esters and mixtures thereof. Preferred nonionic surfactants include alkoxylates. Still more preferably, the concentrated laundry detergent composition of the present invention, comprises 1 to 35 wt% (preferably, 2 to 20 wt%; more preferably, 2 to 15 wt%; most preferably, 3 to 7 wt%), based on weight of the concentrated laundry detergent composition, of a nonionic surfactant; wherein the nonionic surfactant is according to formula A wherein w is an average of 5 to 40 (preferably, 7 to 27; more preferably, 8 to 20; most preferably, 7 to 12); wherein R⁵ is selected from the group consisting of a hydrogen and a linear or branched C_1-20 alkyl group (preferably, a hydrogen, and a linear or branched C_1-15 alkyl group; more preferably, a linear C_1-15 alkyl group); wherein R⁶ is selected from the group consisting of a linear or branched C1-20 alkyl group and a linear or branched C1-4 hydroxyalkyl group (preferably, a linear or branched C_1-15 alkyl group and a linear or branched C_1-4 hydroxyalkyl group; more preferably, a linear C_1-15 alkyl group and a linear or branched C_1-3 hydroxyalkyl group; most preferably, a linear C_1-15 alkyl group); wherein each R⁷ is independently selected from the group consisting of a hydrogen, a methyl group, an ethyl group, a n-propyl group, an iso-propyl group, a n-butyl group, a 2-butyl group and a 2-methyl-2-butyl group (preferably, a hydrogen, a methyl group and an ethyl group; more preferably, a hydrogen and a methyl group; most preferably, a hydrogen); and with the proviso that sum of the total number of carbon atoms in R⁵ and R⁶ is 5 to 21 (preferably, 6 to 20 carbon atoms; more preferably, 7 to 18 carbon atoms; most preferably, 11 to 15 carbon atoms). Still more preferred nonionic surfactants are according to formula I; wherein w is an average of 8 to 16; wherein R⁵ is selected from the group consisting of a hydrogen and a linear C_1-15 alkyl group; wherein R⁶ is selected from the group consisting of a linear or branched C_1-15 alkyl group and a linear or branched C_1-4 hydroxyalkyl; wherein R⁷ is selected from the group consisting of a hydrogen, a methyl group and an ethyl group; and with the proviso that the sum of the total number of carbon atoms in R⁵ and R⁶ is 6 to 20. Most preferred nonionic surfactants are according to formula I; wherein w is an average of 7 to 12; wherein R⁵ is selected from the group consisting of a hydrogen and a linear C_1-15 alkyl group; wherein R⁶ is selected from the group consisting of a linear C_1-15 alkyl group and a linear or branched C_1-3 hydroxyalkyl group; wherein R⁷ is a hydrogen; and with the proviso that the sum of the total number of carbon atoms in R⁵ and R⁶ is 7 to 18.

[0018] Preferably, the concentrated laundry detergent composition of the present invention, comprises 2 to 25 wt% (preferably, 5 to 20 wt%; more preferably, 6 to 15 wt%; most preferably, 8 to 12 wt%), based on weight of the concentrated laundry detergent composition, of an anionic alcohol ethoxysulfate surfactant of formula I; wherein each R¹ and R² is independently a C_1-16 alkyl group (preferably, a C_1-15 alkyl group; more preferably, a C_1-14 alkyl group; most preferably, a linear C_1-13); wherein the sum of the carbon atoms in R¹ and R² is 7 to 17 (preferably, 10 to 16; more preferably, 12 to 16; most preferably, 14 to 16)(preferably, wherein R¹ and R² are linear alkyl groups; more preferably, wherein R¹ is a methyl group and R² is a linear C_10-14 alkyl group; most preferably, wherein R¹ is a methyl group and R² is a linear C₁₂ alkyl group or a linear C₁₄ alkyl group); wherein M⁺ is a cation balancing the negative charge of the -SO₃- anion in formula I (preferably, wherein M⁺ is a cation selected from the group consisting of a nitrogen containing cation (e.g., an ammonium cation), a metal cation (e.g., an alkali metal cation, an alkaline earth metal cation), a boron containing cation and a phosphorous containing cation; more preferably, an ammonium cation, an alkali metal cation and an alkaline earth metal cation; still more preferably, an ammonium cation, a sodium cation and a calcium cation; most preferably, a sodium cation); and wherein x is 1 in 95 to 100 mol% (preferably, 96 to 100 mol%; more preferably, 97 to 100 mol%; most preferably, 97.5 to 100 mol%) of the anionic alcohol ethoxysulfate surfactant of formula I (preferably, as determined using ¹³C nuclear magnetic resonance characterization).

[0019] Preferably, the anionic alcohol ethoxysulfate surfactant of formula I contains < 9 ppm (preferably, < 8 ppm; more preferably, < 7 ppm; still more preferably, < 6 ppm; yet more preferably, < 5 ppm; still yet more preferably, < 4 ppm; yet still more preferably, < 3 ppm; still even more preferably, < 2 ppm; yet even more preferably, < 1 ppm; still yet even more preferably, < 0.25 ppm; most preferably, less than the detectable limit), based on solids weight of the anionic alcohol ethoxysulfate surfactant of formula I, of 1,4 dioxane (preferably, wherein the 1,4 dioxane content is measured by liquid injection low temperature gas chromatography-mass spectrometry method for organic layer and liquid chromatography-mass spectrometry method for aqueous layer).

[0020] Preferably, the anionic alcohol ethoxysulfate surfactant of formula I contains < 2 wt% (preferably, < 1.75 wt%; more preferably, < 1.5 wt%; still more preferably, < 1.25 wt%; yet more preferably, < 1.1 wt%; most preferably, < 1 wt%), based on solids weight of the anionic alcohol ethoxysulfate surfactant of formula I, of an alcohol sulfate surfactant of formula IV wherein each R³ and R⁴ is independently a C_1-16 alkyl group; wherein the sum of the carbon atoms in R³ and R⁴ is 7 to 17; and wherein A⁺ is a cation balancing the negative charge of the -SO₃- anion in formula IV (preferably, wherein A⁺ is a cation selected from the group consisting of a nitrogen containing cation (e.g., an ammonium cation), a metal cation (e.g., an alkali metal cation, an alkaline earth metal cation), a boron containing cation and a phosphorous containing cation; more preferably, an ammonium cation, an alkali metal cation and an alkaline earth metal cation; still more preferably, an ammonium cation, a sodium cation and a calcium cation; most preferably, a sodium cation).

[0021] Preferably, the concentrated laundry detergent composition of the present invention comprises an anionic alcohol ethoxysulfate surfactant of formula I as described above, wherein the anionic alcohol ethoxysulfate surfactant of formula I has elevated thermal stability. More preferably, the concentrated laundry detergent composition of the present invention comprises an anionic alcohol ethoxysulfate surfactant of formula I as described above, wherein the anionic alcohol ethoxysulfate surfactant of formula I has enhanced thermal stability. The term “elevated thermal stability” as used herein and in the appended claims means that the anionic alcohol ethoxysulfate surfactant of formula I when heated to 110 °C contains < 9 ppm (preferably, < 8 ppm; more preferably, < 7 ppm; still more preferably, < 6 ppm; yet more preferably, < 5 ppm; still yet more preferably, < 4 ppm; even more preferably, < 3 ppm; still even more preferably, < 2 ppm; yet even more preferably, < 1 ppm; most preferably, < 0.5 ppm), based on solids weight of the anionic alcohol ethoxy sulfate surfactant of formula I, of 1,4 dioxane (preferably, wherein the 1,4 dioxane content is measured by liquid injection low temperature gas chromatography-mass spectrometry method for organic layer and liquid chromatography-mass spectrometry method for aqueous layer). The term “enhanced thermal stability” as used herein and in the appended claims means that the anionic alcohol ethoxysulfate surfactant of formula I when heated to 280 °C contains < 10 ppm, based on solids weight of the anionic alcohol ethoxysulfate surfactant of formula I, of 1,4 dioxane (preferably, wherein the 1,4 dioxane content is measured by liquid injection gas chromatography-mass spectrometry method for organic layer and liquid chromatography-mass spectrometry method for aqueous layer).

[0022] Preferably, the concentrated laundry detergent composition of the present invention, further comprises 0 to 62 wt% (preferably, 0 to 53 wt%; more preferably, 5 to 47 wt%; most preferably, 21 to 25 wt%), based on weight of the laundry detergent formulation, of the additional anionic surfactant; wherein the additional anionic surfactant is different from the anionic alcohol ethoxysulfate surfactant of formula I. More preferably, the concentrated laundry detergent composition of the present invention, further comprises 0 to 62 wt% (preferably, 0 to 53 wt%; more preferably, 5 to 47 wt%; most preferably, 21 to 25 wt%), based on weight of the laundry detergent formulation, of the additional anionic surfactant; wherein the additional anionic surfactant is selected from the group consisting of alkyl sulfates, alkyl benzene sulfates, alkyl benzene sulfonic acids, alkyl benzene sulfonates, paraffin sulfonic acids, paraffin sulfonates, olefin sulfonic acids, olefin sulfonates, alpha-sulfocarboxylates, esters of alpha-sulfocarboxylates, alkyl glyceryl ether sulfonic acids, alkyl glyceryl ether sulfonates, sulfates of fatty acids, sulfonates of fatty acids, sulfonates of fatty acid esters, alkyl phenols, 2-acryloxy-alkane-l-sulfonic acid, 2-acryloxy-alkane-l-sulfonate, amine oxides and mixtures thereof; and wherein the additional anionic surfactant is different from the anionic alcohol ethoxysulfate surfactant of formula I. Still more preferably, the concentrated laundry detergent composition of the present invention, further comprises 0 to 62 wt% (preferably, 0 to 53 wt%; more preferably, 5 to 47 wt%; most preferably, 21 to 25 wt%), based on weight of the laundry detergent formulation, of the additional anionic surfactant; wherein the additional anionic surfactant is selected from the group consisting of C_8-20 alkyl benzene sulfates, C_8-20 alkyl benzene sulfonic acid, C_8-20 alkyl benzene sulfonate, paraffin sulfonic acid, paraffin sulfonate, alpha-olefin sulfonic acid, alpha-olefin sulfonate, C_8-20 alkyl phenols, amine oxides, sulfonates of fatty acids, sulfonates of fatty acid esters and mixtures thereof. Yet more preferably, the concentrated laundry detergent composition of the present invention, further comprises 0 to 62 wt% (preferably, 0 to 53 wt%; more preferably, 5 to 47 wt%; most preferably, 21 to 25 wt%), based on weight of the laundry detergent formulation, of the additional anionic surfactant; wherein the additional anionic surfactant is selected from the group consisting of C_12-16 alkyl benzene sulfonic acid, C_12-16 alkyl benzene sulfonate, C_12-18 paraffin-sulfonic acid, C_12-18 paraffin-sulfonate and mixtures thereof. Most preferably, the concentrated laundry detergent composition of the present invention, further comprises 0 to 62 wt% (preferably, 0 to 53 wt%; more preferably, 5 to 47 wt%; most preferably, 21 to 25 wt%), based on weight of the laundry detergent formulation, of the additional anionic surfactant; wherein the additional anionic surfactant is selected from the group consisting of C_12-16 alkyl benzene sulfonic acid, C12-16 alkyl benzene sulfonate and mixtures thereof.

[0023] Preferably, the concentrated laundry detergent composition of the present invention, comprises 25 to 65 wt% (preferably, 30 to 60 wt%; more preferably, 35 to 55 wt%; most peferably, 40 to 50 wt%), based on weight of the concentrated laundry detergent composition, of a cleaning surfactant; wherein the cleaning surfactant comprises a blend of a nonionic surfactant and an anionic surfactant; wherein the anionic surfactant comprises an anionic alcohol ethoxysulfate surfactant of formula I; and wherein a weight ratio of the nonionic surfactant to the anionic surfactant in the blend is 10:1 to 1:15 (preferably, 5:1 to 1:12; more preferably, 1:1 to 1:10, most preferably, 1:6 to 1:10).

[0024] Preferably, the concentrated laundry detergent composition of the present invention comprises 0 to 15 wt% (preferably, 0.5 to 10 wt%; more preferably, 1 to 7.5 wt%; most preferably, 2 to 4 wt%), based on weight of the concentrated laundry detergent composition, of a fatty acid (preferably, oleic acid).

[0025] Preferably, the concentrated laundry detergent composition of the present invention comprises 0 to 15 wt% (preferably, 1 to 12 wt%; more preferably, 3 to 10 wt%; most preferably, 5 to 9 wt%), based on weight of the concentrated laundry detergent composition, of a neutralizing agent (e.g., triethanolamine, diethanolamine, monoethanolamine, sodium hydroxide). More preferably, the concentrated laundry detergent composition of the present invention comprises 0 to 15 wt% (preferably, 1 to 12 wt%; more preferably, 3 to 10 wt%; most preferably, 5 to 9 wt%), based on weight of the concentrated laundry detergent composition, of a neutralizing agent; wherein the neutralizing agent is selected from the group consisting of triethanolamine, diethanolamine, monoethanolamine, sodium hydroxide and mixtures thereof. Most preferably, the concentrated laundry detergent composition of the present invention comprises 0 to 15 wt% (preferably, 1 to 12 wt%; more preferably, 3 to 10 wt%; most preferably, 5 to 9 wt%), based on weight of the concentrated laundry detergent composition, of a neutralizing agent; wherein the neutralizing agent includes monoethanolamine.

[0026] Preferably, the concentrated laundry detergent composition of the present invention, further comprises an additive. Preferably, the concentrated laundry detergent composition of the present invention, further comprises an additive selected from the group consisting of an amphoteric/zwitterionic surfactant; a bleach activator (tetra acetyl ethylene diamine (TAED)); a bleaching agent (e.g., sodium percarbonate, sodium perborate, sodium hypochlorite); a builder (e.g., sodium bicarbonate, sodium carbonate, zeolites, sodium citrate, sodium tripolyphosphate and aminocarboxylates (such as methylglycine diacetic acid, sodium salt of glutamic acid diacetic acid, sodium salt)); a cationic surfactant; a colorant; a conditioning agent; a dye; an enzyme (e.g., proteases, cellulases, lipases, amylases, mannanases); a filler; a fluorescent whitening agent; a foam control agent (e.g., polydimethylsiloxane); a fragrance (e.g., essential oils such as D-limonene); a hydrotrope (e.g., sodium xylene sulfonate); an optical brightener; a pigment; a pH buffering agent; a preservative; a rheology modifier; a stabilizer; a structurant; a softening agent (e.g., softening silicone, cationic polymer) and mixtures thereof.

[0027] Preferably, the method of washing a soiled cotton article of the present invention, comprises: providing a soiled cotton article; providing a wash water; providing a rinse water; providing a concentrated laundry detergent composition of the present invention; applying the wash water and the concentrated laundry detergent composition to the soiled cotton article to provide a washed cotton article; and then rinsing the washed cotton article with the rinse water.

[0028] Preferably, in the method of washing a soiled cotton article of the present invention, the soiled cotton article is treated with the concentrated laundry detergent composition and the wash water using well known techniques. Preferably, the concentrated laundry detergent composition is mixed with the wash water at a weight ratio of concentrated laundry detergent composition to wash water of 1 : 100 to 1 : 1 ,000.

[0029] Some embodiments of the present invention will now be described in detail in the following Examples.

Experimental Materials

Synthesis SI: C₁₂EO

[0030] A 3 liter (L) 3-neck glass round bottom flask, equipped with an overhead stirred through the center neck, reflux condenser and-a heating jacket was used for the etherification of 1 -dodecene and monoethylene glycol with the catalyst. To ensure good mixing, a pitch blade impeller was used for agitation. A reaction mixture of 551.7 grams (g) ethylene glycol and 505.8 g 1-dodecene was prepared and loaded in the reactor together with 61-g catalyst in powdered form at 23 °C. The impeller stirring rate was set to be at 400 revolutions per minute (“rpm”). The reactor was heated to 135 °C in over the course of 30 minutes, held at 135 °C for 18 hours and then the reactor was cooled down to 23 °C by shutting off the heater. The reaction mixture was separated into a monoethylene glycol and catalyst phase and an olefin phase using a separation funnel.

[0031] A 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 by an IKA heated stir-plate. The distillation pot was charged with the combined olefin phase 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 raised to 75 °C and unreacted dodecane was collected at a distillation head temperature of 25 °C to 50 °C and a pressure of 13.3-40 pascals (Pa). The heating block temperature was raised gradually to 140 °C and an intermediate fraction containing both monoether alcohol ethoxylates and dodecenes was recovered while the head temperature increased from 50 °C to 75 °C at a pressure of 13 Pa. The C₁₂EO 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 raised gradually to 200 °C and an intermediate fraction containing both monoether alcohol ethoxylates and diether was collected while the head temperature increased from 115 °C to 130 °C at a pressure of 6 Pa. The distillation was discontinued and the diether, which remained in the pot, was collected. The C₁₂EO was carried to the next sulfation process to make sulfate anionic surfactant.

Synthesis S2; C₁₄EO

[0032] A 300 mL Parr reactor with a heating jacket and controller was used for the etherification of 1 -tetradecene and monoethylene glycol with a catalyst. To ensure good mixing, a pitch blade impeller was used for agitation.

[0033] The reaction mixture of 100.0 g monoethylene glycol and 100.0 g 1-tetradecene was prepared and loaded in the reactor together with 10.0 g powder form catalyst at 23 °C. The impeller stirring rate was set to be at least 600 rpm. The reactor was heated up to 135 °C in 30 minutes, held at 135 °C for 6 hours and then the reactor was cooled down to room temperature by shutting off the heater. The reaction mixture was separated by a separation funnel. The reaction mixture was separated into a monoethylene glycol and catalyst phase and an olefin phase using a separation funnel. Fifteen batches were generated and the olefin phases were collected and combined for distillation.

[0034] The same distillation apparatus as used in the Synthesis SI was used for distillation of the C14EO. The distillation pot was charged with the products in the olefin phase from multiple batch reactor runs 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 raised to 95 °C and unreacted 1-tetradecene was collected at a distillation head temperature of 30 °C to 60 °C at a pressure of 27 Pa to 5 Pa. The heating block temperature was raised gradually to 170 °C and an intermediate fraction containing both monoether and tetradecene was recovered while the head temperature increased from 60 °C to 85 °C at a pressure of 7 Pa to 5 Pa. The C₁₄EO was collected at a head temperature of 80 °C to 115 °C and a pressure of 8 Pa to 5 Pa. The distillation was discontinued when no more material would distill over with the pot temperature set at 170 °C. Synthesis S3: C₁₂EO Sulfate

[0035] All chemical manipulations were conducted under a dry nitrogen atmosphere. Prior to the experiment all glassware was heated in a laboratory oven to remove residual water. A 2-L three-neck round bottom flask was loaded with dichloromethane (500 mL) and C₁₂EO prepared according to Synthesis SI (48.4 g, 0.21 mol, 1.0 equivalents). The reaction flask was equipped with an overhead mechanical stirrer, additional funnel, and thermocouple. Next, chlorosulfonic acid (14.5 mL, 0.221 mol, 1.1 equivalents) was carefully loaded into the additional funnel. The reaction flask was then submerged into an ice-bath and allowed to cool for 20 minutes, down to 0 °C. Once the reaction was cooled, chlorosulfonic acid was added to the reaction flask dropwise, at a rate of approx. 1.0 mL per minute, over approximately 20 minutes. During the addition of chlorosulfonic acid the reaction temperature did not exceed 5 °C. After the addition, the reaction was allowed to react, and the temperature was kept between 0 and 5 °C, for 3 hours. At this time, the reaction was neutralized by slow dropwise addition of an aqueous NaOH solution (18.0 g NaOH in 500 mL of water, 0.9 molar). The rate of addition was slow enough to not exceed 5 °C over the course of addition. The addition of the aqueous NaOH solution continued until the reaction became basic. The crude biphasic product was analyzed for dioxane content.

Dichloromethane was then carefully removed from the crude biphasic product in vacuo. During the removal of the dichloromethane, a large amount of foam was observed. Upon removal of the dichloromethane, the remaining aqueous solution was placed in a freeze drier/lyophilizer to yield a secondary alcohol ethoxylate sulfate product, C₁₂EO Sulfate, as a whiteish solid (47.7 grams). The product was further purified by dissolving in hot anhydrous ethanol (1 L), filtering and recrystallizing by cooling. The resulting solid was then dried in a vacuum oven. The purified product was used for the perfomance and property testing.

Synthesis S4; C₁₄EO Sulfate

[0036] All chemical manipulations were conducted under a dry nitrogen atmosphere. Prior to the experiment all glassware was heated in a laboratory oven to remove residual water. A 2-L three-neck round bottom flask was loaded with dichloromethane (500 mL) and C14EO prepared according to Synthesis S2 (49 g, 0.189 mol, 1.0 equivalents). The reaction flask was equipped with an overhead mechanical stirrer, additional funnel, and thermocouple. Next, chlorosulfonic acid (13.0 mL, 0.199 mol, 1.1 equivalents) was carefully loaded into the additional funnel. The reaction flask was then submerged into an ice-bath and allowed to cool for 20 minutes, down to 0 °C. Once the reaction was cooled, chlorosulfonic acid was added to the reaction flask dropwise, at a rate of approximately 1.0 mL per minute, over approximately 20 minutes. During the addition of chlorosulfonic acid the reaction temperature did not exceed 5 °C. After the addition, the reaction was allowed to react and the temperature was kept between 0 °C and 5 °C, for 3 hours. At this time, the reaction was neutralized by slow dropwise addition of aqueous NaOH (18.0 g in 500 mL of water, 0.9 molar). The rate of addition was slow enough to not exceed 5 °C over the course of addition. The addition of the aqueous NaOH solution continued until the reaction became basic. The crude biphasic product was analyzed for dioxane content. Dichloromethane was then carefully removed from the biphasic product in vacuo. During the removal of DCM, a large amount of foam was observed. Upon removal of DCM, the remaining aqueous solution was placed in a freeze drier/lyophilizer to give the secondary alcohol ethoxylate sulfate product. The product was then further purified by dissolving in hot anhydrous ethanol (1 L), filtering and recrystallizing by cooling. The resulting solid was then dried in a vacuum oven. The CuEO sulfate percent active sulfate content was determined via cationic titration. The purified product was used for the performance and property testing.

Synthesis S5: ALEO1 Sulfate

[0037] ALEO1 sulfate was prepared from ALEO1 in the same manner as described in Synthesis S3.

Synthesis S6: SA3EO Sulfate

[0038] SA3EO sulfate was prepared from SA3EO in the same manner as described in Synthesis S3.

Synthesis S7: C₁₆EO

[0039] A 2 L glass reactor with a heating jacket and controller was used for the etherification of 1-tetradecene and monoethylene glycol with a catalyst. To ensure good mixing, a pitch blade impeller was used for agitation.

[0040] The reaction mixture of 434.0 g monoethylene glycol and 537.0 g 1-hexadecene was prepared and loaded in the reactor together with 48.0 g powder form catalyst at 23 °C. The impeller stirring rate was set to be at least 600 rpm. The reactor was heated up to 145 °C in 30 minutes, held at 145 °C for 7 hours and then the reactor was cooled down to room temperature by shutting off the heater. The reaction mixture was separated by a separation funnel. The reaction mixture was separated into a monoethylene glycol and catalyst phase and an olefin phase using a separation funnel. Fifteen batches were generated and the olefin phases were collected and combined for distillation. [0041] The same distillation apparatus as used in the Synthesis SI was used for distillation of the C16EO. The distillation pot was charged with the products in the olefin phase from multiple batch reactor runs 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 raised to 250 °C and unreacted 1-hexadecene was collected at a distillation head temperature of 40 °C to 130 °C at a pressure of 5 mm Hg. The heating block temperature was raised gradually to 320 °C and an intermediate fraction containing both monoether and hexadecene was recovered while the head temperature increased from 40 °C to 180 °C at a pressure of 1.13 mm Hg. The CieEO was collected at a head temperature of 180 °C and a pressure of 1.13 mm Hg. The distillation was discontinued when no more material would distill over with the pot temperature set at 400 °C.

Synthesis S8: C₁₆EO Sulfate

[0042] All chemical manipulations were conducted under a dry nitrogen atmosphere. Prior to the experiment all glassware was heated in a laboratory oven to remove residual water. A 2-L three-neck round bottom flask was loaded with dichloromethane (500 mL) and CieEO prepared according to Synthesis S7 (44.05 g, 0.154 mol, 1.0 equivalents). The reaction flask was equipped with an overhead mechanical stirrer, additional funnel, and thermocouple. Next, chlorosulfonic acid (10.5 mL, 0.161 mol, 1.03 equivalents) was carefully loaded into the additional funnel. The reaction flask was then submerged into an ice-bath and allowed to cool for 20 minutes, down to 0 °C. Once the reaction was cooled, chlorosulfonic acid was added to the reaction flask dropwise, at a rate of approximately 1.0 mL per minute, over approximately 20 minutes. During the addition of chlorosulfonic acid the reaction temperature did not exceed 5 °C. After the addition, the reaction was allowed to react and the temperature was kept between 0 °C and 5 °C, for 3 hours. At this time, the reaction was neutralized by slow dropwise addition of aqueous NaOH (18.0 g in 500 mL of water, 0.9 molar). The rate of addition was slow enough to not exceed 5 °C over the course of addition. The addition of NaOH continued until the reaction became basis. Dichloromethane was then carefully removed from the biphasic reaction in vacuo. During the removal of DCM, a large amount of foam was observed. Upon removal of DCM, the remaining aqueous solution was placed in a freeze drier/lyophilizer to give the secondary alcohol ethoxylate sulfate product. The product was then further purified by dissolving in hot anhydrous ethanol (1 L), filtering and recrystallizing by cooling. The resulting solid was then dried in a vacuum oven. The CieEO sulfate percent active sulfate content was determined via cationic titration. Active Sulfate (EO=0) Content of Surfactants

[0043] The active sulfate concentration in the surfactants noted in TABLE 1 was determined using a procedure modification of Tumey, M.E., Cannell, D.W. Alkaline methylene blue method for determination of anionic surfactants and for amine oxides in detergents. J. Am. Oil Chem. Soc., 42, 544-46 (1965) and Epton, S.R. A new method for the rapid titrimetric analysis of sodium alkyl sulphates and related compounds. Trans. Faraday Soc., 44, 226-30 (1948).

Determination of Moles of Hyamine (MOIH)

[0044] Sodium Dioctyl Sulfosuccinate (SDOSS), Control Solution: A 20 mL scintillation vial was loaded with 0.8 g (± O.lmg) of sodium dioctyl sulfosuccinate of known purity (>99%). The vial was filled with 10 mL of deionized water and was transferred to a 250 mL volumetric flask. This process was repeated 3-5 times to ensure the sample was transferred. Once the transfer was complete, the sample was diluted to 250 mL with deionized water. The flask was then stoppered, and the solution was thoroughly mixed by repeatedly inverting the flask.

[0045] Methylene Blue Chloride Solution: A 20 mL scintillation vial was loaded with 0.050 g (± 0.005) of methylene blue chloride. The vial was filled with 10 mL of deionized water and was transferred to a 1 L graduated cylinder. This process was repeated 3-5 times to ensure the sample was transferred. The methylene blue solution was then diluted to 1 L with deionized water. This solution was then transferred to a 2 L glass jug. Once transfer was complete, 10 mL of concentrated sulfuric acid and 50 g of anhydrous sodium sulfate was carefully added to the methylene blue solution and mixed thoroughly.

[0046] Hyamine 1622 Solution: A 20 mL scintillation vial was loaded with 1.1 grams of Hyamine 1622. The vial was filled with 10 mL of deionized water and was transferred to a 1 L volumetric flask. This process was repeated 3-5 times to ensure the sample was transferred. The sample was then diluted to 1 L with deionized water. The solution was thoroughly mixed by repeatedly inverting the flask and was then filtered into a 1 L glass bottle.

[0047] Standardization of Hyamine Solution: A 100 mL glass bottle was loaded with 5 mL of the sodium dioctyl sulfosuccinate solution via pipette. Next, 20 mL of methylene blue chloride solution and 25 mL of chloroform was added via pipette. The 100 mL bottle was capped and shaken thoroughly for several seconds. Hyamine 1622 solution was then titrated into the methylene blue/chloroform biphasic mixture at 0.5 mL increments. After each addition the bottle was capped and shaken vigorously. The additions of Hyamine 1622, in 0.5 mL increments, were continued until the blue color in the chloroform layer (or lower layer) began to migrate to the upper layer. At this point, the incremental additions of Hyamine 1622 were decreased to 0.1 mL and continued until the endpoint is reached. The endpoint was reached when the blue color intensity of both layers was matched. This standardization was completed in triplicate. The moles of the Hyamine 1622 was then calculated using the following formula wherein Mol_H is the moles of hyamine; CSvoi is the volume of control solution tested (i.e., 5 mL); CS_mass is the total grams of control (SDOSS) added to the control solution (g); Hcsvoi is the amount of hyamine solution required to reach the endpoint (mL); CS_MW is the molecular weight of the control solution, SDOSS (i.e., 444.56 g/mol).

Determination of active sulfate in surfactants

[0048] A 20 mL scintillation vial was loaded with 0.9 to 1.1 grams of surfactant sample, weighed to the nearest 0.1 mg. The vial was then filled with 10 mL of deionized water and transferred to a 250 mL volumetric flask. This process was repeated 3-5 times to ensure the sample was transferred. Once the transfer was complete, the sample was diluted with deionized water to 250 mL. The flask was then stoppered, and the solution was thoroughly mixed by repeatedly inverting the flask. Next, a 100 mL glass bottle was loaded with 5 mL of the test sample solution via pipette. The 100 mL glass bottle was then loaded with 20 mL of the methylene blue solution and 25 mL of chloroform via pipette. The glass bottle was capped and shaken vigorously for several seconds. Hyamine 1622 solution was then titrated into the methylene blue/chloroform biphasic mixture at 0.5 mL increments. After each addition the bottle was capped and shaken vigorously. The additions of Hyamine 1622, in 0.5 mL increments, was continued until the blue color in the chloroform layer (or lower layer) began to migrate to the upper layer. At this point, incremental additions of Hyamine 1622 were reduced to 0.1 mL and continued until the endpoint was reached. The endpoint being the point at which the color intensity of both layers was matched. Each sample was repeated in triplicate. The percent active sulfate content (wt%) was calculated using by the following formula: wherein H_SVol is the amount of Hyamine solution required to reach the endpoint (mL); MOIH is the moles of Hyamine (determined from standard solution described above); SMW is the weight average molecular weight of surfactant (g/mol); S_Vol is the volume of surfactant tested (i.e., 5 mL); S_mass is the total grams of surfactant added to 250 mL solution (g). The results are provided in TABLE 1.

EQ Distribution of Surfactants

[0049] The distribution of EO adducts in the surfactants listed in TABLE 1 was determined by NMR or UHPLC-MS as noted using the methodology set forth below with the results provided in TABLE 1.

Nuclear Magnetic Resonance EO Distribution Characterization (NMR)

[0050] Samples of surfactant to be analyzed were prepared by dissolving the surfactant in deuterated dimethyl sulfoxide containing 0.025 M chromium (III) acetylacetonate. Nuclear magnetic resonance (¹³C NMR) spectra of the samples were then collected on a Bruker AVANCE 400 MHz spectrometer equipped with a 10 mm cryo-probe set to 25 °C, with the following parameters: a 90°-pulse, inverse-gated decoupling, a 1.38 second acquisition time, and a 6.4 second recycle delay. 2048 scans were collected. The data was processed in MNOVA, and the chemical shifts were referenced to the solvent peak at 39.52 ppm. A DEPT- 135 experiment was also acquired with the same parameters, but with a 2.0 second recycle delay, and 2048 acans. The ratios of different EO adducts are calculated by integrating and comparing the intensity of the ethylene oxide alcohol end groups from about 60-61 ppm, the ethylene oxide backbone groups from about 69-70 ppm, the ethylene oxide end group ether peak from about 71-72 ppm, the unreacted primary alcohol peaks from about 60-61 ppm, and the unreacted secondary alcohol peaks from about 65-66 ppm.

Sodium lauryl ether sulfate analysis by UHPLC-MS

[0051] Ultra high performance liquid chromatography-mass spectrometry (UHPLC-MS) conditions:

[0052] Procedure: The compositions containing commercial surfactants were analyzed by ultra-high performance liquid chromatography mass spectrometry (UHPLC-MS) with electrospray ionization (ESI). For the analysis, stock solutions were prepared at concentrations of 25 ppm in a 50/50 mixture of methanol/water. The alcohol ethoxylate samples were diluted 1:100 in 50/50 methanol/water in duplicate and vortexted for a few seconds. Then they were diluted 1:10 in 50/50 methonol/water to give a final dilution of 1:1,000. Ethal® LA-4 was the standard used for the commercial 1-mole sodium laureth sulfate and Ethal® LA-7 was the standard used for the commercial 3-mole 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 the 1:1,000 preparation in 50/50 methanol/water to give a final solution of 1:20,000. POLYSTEP® B-N-5 was used as the standard for the alkyl sulfate analysis. Standards were prepared in 50/50 methanol/water at concentrations of 5 ppm, 2 ppm, 1 ppm and 0.5 ppm. [0054] The samples were analyzed using a Waters ACQUITY® UPLC system equipped with a Waters BEH Cl 8 1.7 μm 1 x 50 mm column. Mass spectrometry was conducted using a Waters LCT Premier TOF Mass Spectrometer with ESI. Measurements were conducted in both positive and negative ion mode. Each sample preparation was injected three times for analysis. The ratios of the different EO adducts were calculated by the peak area and are reported in TABLE 1.

TABLE 1

[0055] At least 95 mol% of the oligomers of the products of Syntheses S4 and S5 had an n of 1 and no more than 5 mol% the oligomers have an n of > 2. Specifically, > 98 mol% of the oligomers of the products of Syntheses S4 and S5 had an n of 1 and < 2 mol% of the oligomers had an n of > 2.

1.4 Dioxane Content of Surfactants

[0056] The 1,4 dioxane content in the surfactants fisted in TABLE 2 was determined by liquid injection low temperature gas chromatography-mass spectrometry (GC-MS) method for organic layer and liquid chromatography-mass spectrometry (LC-MS) method for aqueous layer as noted using the methodology set forth below with the results provided in TABLE 2. [0057] Gas chromatography-Mass spectrometry (GC-MS) conditions for organic layer 1,4 dioxane measurement:

[0058] Standards were prepared by adding dioxane in tetrahydrofuran (“THF”) and diluting down to 0.1 - 100 ppm.

[0059] Samples were prepared by mixing 3.3 g from the organic (DCM) layer of the crude process mixture and 6.7 g of THF, the solution was then allowed to shake for about 20 minutes. The solids were then centrifuged to the bottom and the supernatant was vialed in an autosampler vial. Spiked samples were prepared by spiking dioxane standard in THF into separate samples at 5-10 ppm.

[0060] Liquid chromatography-mass spectrometry (LC-MS) conditions for aqueous layer 1,4 dioxane content measurement:

[0061] Samples were injected neat or diluted with water 1 :4. Standards were prepared by preparing a dioxane in THF stock solution and the diluting down with water to 0.1-100 ppm.

Calculation of Dioxane Content Relative to Solids

[0062] The ppm of dioxane content relative to solids content in the sample is calculated according to the following equation.

TABLE 2

[0063] The gas chromatography results for the SA3EO sulfate surfactant indicate the secondary alcohol with an average of 3 moles of ethylene oxide per molecule contained 2 ppm of 1,4 dioxane in the organic phase at 110 °C and indicates the potential for structures having 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 1,471 ppm 1,4 dioxane in the organic phase. This result indicates that sulfated surfactants having n > 2 may develop observable 1,4 dioxane at 110 °C, but also that such surfactants may be unstable at elevated temperatures of 280 °C which could result in significant 1,4 dioxane formation.

Similarly to SA3EO sulfate, gas chromatography results for the ALEO1 sulfate surfactant indicate the formation of > 9 ppm of 1,4 dioxane relative to the solids at 110 °C. Further, the ALEO1 sulfate surfactant also exhibited a large generation of 1,4 dioxane (259 ppm) at 280 °C, suggesting that the ALEO1 sulfate surfactant lacks stability at high temperatures. The inventive C₁₂EO sulfate surfactant with > 95 mol% having n of 1 and < 5 mol% having n > 2 demonstrates a low 1,4 dioxane content. Surprisingly, the inventive C₁₂EO sulfate surfactant also demonstrates an extremely low 1,4 dioxane content and falls below the limit of detection (LOD) of the GC and LC methods. Using the LOD as a basis, this indicates that the dioxane content for the C₁₂EO sulfate is < 1.6 ppm relative to solids, at 110 °C. Interestingly, the inventive C₁₂EO sulfate, when the inlet temperature is increased to 280 °C, the 1 ,4 dioxane content of the material is still less than 1 ppm (i.e., 0.58 ppm), which indicates that the inventive C₁₂EO sulfate has increased thermal stability relative to the comparative materials.

Comparative Examples CF1-CF2 and Examples F1-F8: Detergent Composition

[0064] Concentrated laundry detergent compositions were prepared in each of Comparative Examples CF1-CF2 and Examples F1-F8 having the formulation as described in TABLE 3 with a pH of 8-8.5 and prepared by standard laundry formulation preparation procedure. The concentrated laundry detergent compositions were observed for formulation stability, with those exhibiting a phase separation being identified as not stable. The results of these observations are reported in TABLE 3.

TABLE 3

Primary Cleaning Performance

[0065] The primary cleaning performance of the liquid laundry detergent formulations of Comparative Examples CF1-CF4 and Examples F1-F8 were assessed in a Launder-Ometer (SDL Atlas, Model M228AA) at a set test temperature of 22 °C using a 30 minute wash cycle. Twenty of the 1.2 liter canisters filled with 500 mL of hardness adjusted water at 100 ppm by mass with 2: 1 Ca²⁺:Mg²⁺ molar ratio were used for each run. The washed fabrics were rinsed in 300 mL of 100 ppm (2/1 Ca²⁺/Mg²⁺) hardness adjusted water at ambient temperature for 5 minutes at 260 osc/min pm on an Eberbach E6000 reciprocal shaker. The stained fabrics and soiled ballasts used in the tests were PCS-S-94 sebum/dust ASTM stains from Testfabrics stitched to a pre-shrunk cotton interlock fabric. The size of the cotton interlock was 5x5 cm. The stained swatches were 2.5 x 3 cm. One 5 x 5 cm cut SBL-CFT soil ballast was added to each canister to provide baseline soil to the wash solution. The total surfactant concentration in the wash liquor was 200 ppm.

Reflectance measurement and Stain Removal Index (SRI)

[0066] The soil removal index (SRI) for each of the Liquid Laundry Detergent formulations evaluated in Primary Cleaning Performance Test were determined using ASTM Method D4265-14. The average SRI taken from 8 swatches per condition (two swatches per pot, 4 pots) is provided in TABLE 4.

[0067] The L*, a* and b* values of the stained fabrics were measured pre and post wash with a Mach 5 spectrophotometer from Colour Consult. The L*, a* and b* values for the unwashed, unstained polycotton fabric was measured in the SRI calculations as follows: wherein US is the unwashed stain area, UF is the unwashed (unstained) fabric area, WS is the washed stain area, ΔE*_(US-UF) is the AE* color difference between the unwashed stain and the unwashed fabric and ΔE*_(WS-UF) is the AE* color difference between the washed stain and the unwashed fabric. The value of AE* is calculated as

ΔE* = (ΔL*² + Δa ² + Δb*²)^1/2. TABLE 4

Anti-redeposition

[0068] The anti-redeposition performance of the combination of the standard liquid laundry detergent + cleaning booster of Comparative Examples CF1-CF4 and Examples F1-F8 was assessed in a Terg-o-tometer Model 7243ES agitated at 90 cycles per minute with the conditions noted in TABLE 5.

TABLE 5

[0069] The antiredeposition performance was determined by calculating the ΔE measured with a MACH 5+ instrument (L, a & b). The results are noted in TABLE 6, wherein ΔE* is according to the equation ΔE* = ΔE_aw ^_ ΔE_bw wherein ΔE_aw is measured from fabrics after washing, and AE_bw is measured from fabrics before washing. A higher ΔE* corresponds with better antiredeposition performance.

TABLE 6

Claims

We claim:

1. A concentrated laundry detergent composition, comprising: a solvent system, wherein the solvent system is a mixture of water and a nonaqueous solvent; a cleaning surfactant; wherein the cleaning surfactant comprises a blend of a nonionic surfactant; an anionic alcohol ethoxysulfate surfactant of formula I wherein each R¹ and R² is independently a C_1-16 alkyl group; wherein the sum of the carbon atoms in R¹ and R² is 7 to 17; wherein M⁺ is a cation balancing the negative charge of the -SO₃- anion of formula I; and wherein n is 1 in 95 to 100 mol% of the anionic alcohol ethoxysulfate surfactant of formula I; and optionally, an additional anionic surfactant; and optionally a fatty acid; and optionally a neutralizing agent; wherein the concentrated laundry detergent composition comprises < 15 wt% , based on weight of the concentrated laundry detergent composition, of water.

2. The concentrated laundry detergent composition of claim 1, wherein the concentrated laundry detergent composition comprises 25 to 65.1 wt%, based on weight of the concentrated laundry detergent composition, of a nonaqueous solvent.

3. The concentrated laundry detergent composition according to claim 2, wherein the anionic alcohol ethoxysulfate surfactant of formula I contains < 9 ppm of 1 ,4 dioxane.

4. The concentrated laundry detergent composition according to claim 3, wherein the concentrated laundry detergent composition contains < 1 wt%, based on solids weight of the concentrated laundry detergent composition, of an alcohol sulfate surfactant of formula n wherein each R³ and R⁴ is independently a C_1-16 alkyl group; wherein the sum of the carbon atoms is R³ and R⁴ is 7 to 17 and wherein A⁺ is a cation balancing the negative charge on the -SO₃- anion in formula II.

5. The concentrated laundry detergent composition according to claim 4, wherein the concentrated laundry detergent composition contains 1 to < 10 wt%, based on weight of the concentrated laundry detergent compositon, of water; and wherein the concentrated laundry detergent composition, further comprises: an additional anionic surfactant; a fatty acid; and a neutralizing agent.

6. The concentrated laundry detergent composition according to claim 5, wherein the laundry detergent formulation comprises:

35 to 61 wt%, based on weight of the concentrated laundry detergent composition, of the solvent system;

1 to 7.5 wt%, based on weight of the concentrated laundry detergent composition, of the fatty acid;

3 to 10 wt%, based on weight of the concentrated laundry detergent composition, of the neutralizing agent; and

35 to 55 wt%, based on weight of the concentrated laundry detergent composition, of the cleaning surfactant; wherein the cleaning surfactant comprises a blend of

2 to 15 wt%, based on weight of the laundry detergent formulation, of the nonionic surfactant;

6 to 15 wt%, based on weight of the laundry detergent formulation, of the anionic alcohol ethoxysulfate surfactant of formula I; and

5 to 47 wt%, based on weight of the laundry detergent formulation, of the additional anionic surfactant; wherein a weight ratio of the nonionic surfactant to anionic surfactants in the blend is 1:1 to 1:10.

7. The concentrated laundry detergent composition according to claim 6, wherein the additional anionic surfactant is a linear alkylbenzene sulfonate surfactant.

8. The concentrated laundry detergent composition according to claim 7, further comprising an additive selected from the group consisting of an amphoteric/zwitterionic surfactant; a bleach activator; a bleaching agent; a builder; a cationic surfactant; a colorant; a conditioning agent; a dye; an enzyme; a filler; a fluorescent whitening agent; a foam control agent; a fragrance; a hydrotrope; an optical brightener; an organic solvent; a pigment; a pH buffering agent; a preservative; a rheology modifier; a stabilizer; a structurant; a softening agent and mixtures thereof.

9. A method of washing a soiled cotton article, comprising: providing a soiled cotton article; providing a laundry detergent composition according to claim 1; providing a wash water; providing a rinse water; applying the wash water and the laundry detergent composition to the soiled cotton article to provide a washed cotton article; and rinsing the washed cotton article with the rinse water.

10. The method of claim 9, wherein the concentrated laundry detergent composition is a concentrated laundry detergent composition according to claim 8.