ISOTROPIC LIQUID CLEANERS COMPRISING MIXTURES OF ACYLISETHIONATE AND METHYL ACYLTAURATE SURFACTANTS

Abstract

The invention relates to an isotropic liquid composition comprising acylisethionate, methylacyltaurate, and an amphoteric, zwitterionic, and / or nonionic surfactant. Unexpectedly, it has been found that monitoring the ratio of isethionate to taurate results in improved foaming.

Description

BRIEF DESCRIPTION OF THE INVENTION The present invention relates to an isotropic personal liquid cleansing composition. Isotropic compositions are those in which the surfactant micelles do not tend to aggregate or form lamellar (liquid crystalline) layers. The composition comprises: 1) from 0.1 to 8%, preferably from 0.5 to 6%, more preferably from 1 to 4% by weight of acylisethionate; 2) from 0.1% to 8%, preferably from 0.5% to 6%, more preferably from 1% to 4% by weight of methyl acyl taurate; 3) from 0.0 to 15%, preferably from 0.1 to 10% and more preferably from 0.5 to 8% by weight of an amphoteric and / or zwitterionic surfactant; and 4) from 0.0 to 8.0%, preferably from 0.001 to 7%, and more preferably from 1 to 6% by weight of nonionic surfactant, provided that the sum of all surfactants is less than 20% by weight and the composition does not simultaneously comprise 0.01% by weight or more of nonionic surfactant and 0.1% by weight or more of amphoteric surfactant (including betaine) and / or zwitterionic surfactant and does not simultaneously comprise 0.0% by weight of amphoteric and / or zwitterionic surfactant and 0.0% by weight of nonionic surfactant, wherein the ratio of acylisethionate to methylacyltaurate surfactant is between 1.5:1 and 1:1.5, and more preferably from 1.25:1 and 1:1.25, and more preferably, 1.1:1 to 1:1.1, and preferably 1:1. In one embodiment of the invention, the ratio of amphoteric, zwitterionic, and / or nonionic surfactant to anionic surfactant is from 1:1 to 4:1, preferably from 1:1 to 3:1, and more preferably from 1.8:1 to 2.2:1, provided that the sum of all surfactants is less than 20% by weight and that the pH of the composition is from 5.0 to 7.4, preferably from 6.0 to 7.3, and wherein the composition is substantially free of the nonionic surfactant. In some embodiments, the pH is from 6.3 to 7.3, inclusive of all intervals therein. In a particularly preferred embodiment, the ratio of amphoteric to anionic surfactant is 2:1. In yet another embodiment of the invention, the amphoteric and / or zwitterionic surfactant constitutes from 0.0 to less than 0.1% by weight of the composition and the non-ionic surfactant is present in an amount of from 0.02 to 8% by weight of the composition. DETAILED DESCRIPTION OF THE INVENTION Except in the examples, or where explicitly stated otherwise, all numbers in this description that indicate quantities of material or reaction conditions, physical properties of materials and / or use shall be understood to be modified by the word "approximately". As used throughout this document, intervals are used as shorthand to describe each and every value within the interval, and therefore all intervals include the values ​​contained therein, unless otherwise stated. Any value within the interval may be selected as the interval term. The use of "and / or" indicates that any value from the list may be chosen individually, or any combination thereof may be selected. To avoid any ambiguity, the phrase "comprising" is intended to mean "including" but not necessarily "consisting of" or "composed of." In other words, the listed steps or options do not need to be exhaustive. Unless otherwise stated, all percentages of quantity or amounts of ingredients used should be understood as weight percentages based on the active weight of the material in the total weight of the composition, which totals 100%. The emulsifier and surfactant may be used interchangeably herein. For the avoidance of doubt, amphoteric surfactants include betaines. Nonionic surfactant, as used herein, includes amine oxides. The invention relates to isotropic liquid cleaning compositions comprising acyl isethionate, methyl acyl taurate, and at least one amphoteric and / or nonionic surfactant. Isotropic compositions are those in which the surfactants form micelles but do not aggregate to form lamellar (liquid crystalline) layers. The invention relates to isotropic cleaning compositions comprising less than 0.2 wt% of the sulfate-based surfactant. In another embodiment, the invention relates to a composition comprising from 0.0001 to less than 0.2 wt% of the sulfate-based surfactant. In yet another embodiment, the invention relates to a composition containing no (0.0 wt%) sulfate-based surfactants. In another embodiment of the invention, the composition comprises less than 3 wt% of betaine, and in yet another embodiment, is betaine-free (0.0 wt%). When the acyl isethionate and acyl methyl taurate are maintained in a ratio of 1.5:1 to 1:1.5; the overall surfactant level is kept to less than 20% by weight of the composition; and the pH is 5.0 to 7.4, preferably 6.0 to 7.3, the softness benefits of the composition of the present invention are achieved while significantly improving foam compared to compositions in which the ratio of acyl isethionate to methyl acyl taurate is outside these ranges. The compositions may optionally comprise amphoteric, zwitterionic, and / or nonionic surfactant, and the ratio of such surfactant to anionic surfactant may be 1:1 and higher. More specifically, the invention comprises: 1) from 0.1 to 8%, preferably from 0.5 to 6%, more preferably from 1 to 4% by weight of acylisethionate; 2) from 0.1% to 8%, preferably from 0.5% to 6%, more preferably from 1% to 4% by weight of methyl acyl taurate; 3) from 0.0 to 15%, preferably from 0.5 to 10% and more preferably from 1 to 8% by weight of an amphoteric and / or zwitterionic surfactant; and 4) from 0.0 to 8%, preferably from 0.001 to 7%, more preferably from 1 to 6% by weight of nonionic surfactant, provided that the sum of all surfactants is less than 20% by weight and the composition does not simultaneously comprise 0.01% by weight or more of the nonionic surfactant and 0.1% by weight or more of the amphoteric surfactant (including betaine) and / or zwitterionic surfactant and does not simultaneously comprise 0.0% by weight of the amphoteric and / or zwitterionic surfactant and 0.0% by weight of the nonionic surfactant, wherein the ratio of acylisethionate to methylacyltaurate surfactant is between 1.5:1 and 1:1.5, and more preferably from 1.25:1 and 1:1.25, and more preferably from 1.1:1 1:1.1, and more preferably 1:1 and further wherein the ratio of point (3) and / or point (4) to the anionic surfactant (for example, components (1) and (2)) is 1:1, preferably 2:1, more preferably 3:1 and still more preferably 4:1 with the additional condition that the pH of the composition is from 5.0 to 7.4, preferably from 6.0 to 7.3. The invention is described in more detail below. The composition may comprise from 0.1 to 8% by weight, preferably from 0.5 to 6% and more preferably from 1 to 4% by weight of acylisethionate. Fatty acylisethionate molecules (e.g., cocoylisethionates) are highly desirable anionic surfactants in cleansing products for skin or hair care, particularly in personal care products, because they lather well, are gentle on the skin, and have good emollient properties. Typically, fatty acylisethionates are produced by the direct esterification of fatty acids or by the reaction of a fatty acid chloride with a carbon chain length of C8 to C20 with an isethionate. A typical fatty acylisethionate surfactant “product” (e.g., a commercially sold or manufactured surfactant product) contains approximately 40 to 95% by weight of the fatty acylisethionate product and 0 to 50% by weight, typically 5 to 40% by weight of free fatty acid, plus isethionate salts, typically less than 5%, and traces (less than 2% by weight) of other impurities. A second required component of the claimed invention is methylacyltaurate. It is present at a level of 0.1 to 8% by weight, preferably 0.5 to 6%, and more preferably 1 to 4% by weight of methylacyltaurates. Methylacyltaurates (or taurides) are a group of mild anionic surfactants. They consist of a hydrophilic head group, N-methyltaurine (2-methylaminoethanesulfonic acid), and a lipophilic residue, a long-chain carboxylic acid (fatty acid), linked by an amide bond. The fatty acids used can be lauric (C12), myristic (C14), palmitic (C16), or stearic (C18) acids, although mixtures of oleic acid (C18:1) and coconut fatty acid (C8C18) are most commonly used. Besides sodium, no other counterion typically plays a significant role (other counterions could be, for example, ammonium or other alkali or alkaline earth metals). According to the invention, as seen in the examples, when the ratio of methylacyltaurate to acylisethionate is 1.5:1 to 1:1.5, preferably 1.25:1 to 1:1.25 and in particular 1:1 (and other requirements are met), the foam volumes are improved. For example, at a total active level of 12%, as shown in Table 1.1 (e.g., 12% total surfactant (amphoteric, zwitterionic, and / or anionic) where the amphoteric surfactant is 8% and the anionic acyl methyltaurate and acyl isethionate are 4% (2% each) total), the foam volume is greater in a 1:1 ratio of taurate to isethionate. The increase is most clearly observed when the dilution is 5.0 g / 250 ml instead of 2.5 g / 250 ml (since there is more product), although the trend is observed even at a lower dilution level. At 9% of the total surfactant (Table 2 in the Example), there is slightly less anionic surfactant (6% to 3% anionic surfactant), so the foam volume is slightly less at the same dilution of 5.0 g / 250 ml, although clearly the foam is greater as the ratio approaches 1:1. In Table 3, the anionic levels are at 2% (4% amphoteric to 2% anionic), so although the same trend is observed (better foam as the ratio approaches 1:1), more product dilution is needed (e.g., 10 g / 250 ml) to show the full effect. At a dilution of 2.5 g / 250 ml, the product level is too low since there is no foam even at 300 ml, and therefore it was not recorded. The foam levels, for the purposes of the invention, must be at least 200 ml, preferably at least 300 ml, when measured at 45 seconds according to the methodology described in the Sita® foam tester below. As stated above, the invention relates to compositions in which the ratio of acylisethionate to methylacyltaurate is 1.5:1 to 1:1.5, preferably 1.25:1 to 1:1.25 and most preferably 1:1. A third component of the invention is a zwitterionic or amphoteric surfactant, preferably amphoteric. The amphoteric surfactants that can be used in this invention include at least one acid group. This group can be a carboxylic or sulfonic acid group. They include quaternary nitrogen and are therefore quaternary amido acids. In general, they must include an alkyl or alkenyl group of 7 to 18 carbon atoms. They will generally conform to a general structural formula: where R1 is an alkyl or alkenyl of 7 to 8 carbon atoms; R2 and R3 are each independently alkyl, hydroxyalkyl or carboxyalkyl of 1 to 3 carbon atoms; n is from 2 to 4; m is 0 to 1; X is an alkylene of 1 to 3 carbon atoms optionally substituted with hydroxyl, and And it is---CO2 — or----SOs---. In one form, the amphoteric agent can be an alkylamido alkylbetaine (e.g., cocoamidopropylbetaine). It can also be an amphoacetate; or a hydroxysultaine (e.g., cocoamidopropyl hydroxysultaine). Zwitterionic surfactants are exemplified by those that can be broadly described as derivatives of quaternary ammonium, phosphonium, and sulfonium aliphatic compounds, in which the aliphatic radicals can be linear or branched, and where one of the aliphatic substituents contains approximately 8 to approximately 18 carbon atoms and one contains an anionic group, for example, carboxylphonate, sulfate, phosphate, or phosphonate. A general formula for these compounds is: (r3)x R— Y(+->— CH2— where R2 contains an alkyl, alkenyl, or hydroxyalkyl radical of approximately 8 to approximately 18 carbon atoms, 0 to approximately 10 portions of ethylene oxide, and 0 to approximately 1 fraction of glycerol; Y is selected from the group consisting of nitrogen, phosphorus, and sulfur atoms; R3 is an alkyl or monohydroxyalkyl group containing approximately 1 to approximately 3 carbon atoms; X is 1 when Y is a sulfur atom and 2 when Y is a nitrogen or phosphorus atom; R4 is an alkylene or hydroxyalkylene of approximately 1 to approximately 4 carbon atoms, and Z is a radical selected from the group consisting of carboxylate, sulfonate, sulfate, phosphonate, and phosphate groups. A fourth component of the invention is a non-ionic surfactant. Nonionic detergents that can be used include, in particular, the reaction products of compounds that have a hydrophobic group and a reactive hydrogen atom, for example, aliphatic alcohols, acids, amides, or alkylphenols with alkylene oxides, especially ethylene oxide, either alone or with propylene oxide. Specific nonionic detergent compounds are alkyl (C6-C22) phenol-ethylene oxide condensates, condensation products of linear or branched primary or secondary aliphatic (C6-C1e) alcohols with ethylene oxide, and products made by condensation of ethylene oxide with the reaction products of propylene oxide and ethylenediamine. Other detergent compounds referred to as nonionic include long-chain tertiary amine oxides, long-chain tertiary phosphine oxides, and dialkyl sulfoxides. In one embodiment of the invention, the nonionic surfactants used herein include laurylamide propylamine oxide, lauramine oxide, cocoamidopropylamine oxide, or mixtures thereof. Such amine oxides are commercially available from suppliers such as Stepan under the name Ammonyx. In the compositions of the invention, the ratio of amphoteric, zwitterionic and / or non-ionic surfactant to anionic surfactant is from 1:1 to 4:1, preferably from 1:1 to 3:1, most preferably from 1.8:1 to 2.2:1. Liquid compositions may include a variety of other ingredients that are typically found in liquid cleansing compositions. In addition to the specific isethionate, taurate, and amphoteric, zwitterionic, and / or non-ionic surfactant, the compositions may comprise small amounts of additional surfactants (normally used in a smaller amount than any of the three surfactants) provided that the total amount of all surfactants is less than 20% by weight of the liquid cleaning composition of the invention. Other surfactants that may be optionally included are cationic surfactants as described in U.S. Patent No. 3,723,325 to Parran Jr. and “Surface Active Agents and Detergents” (Vol. I and II) by Schwartz, Perry & Berch, both of which are incorporated herein by reference. Water-soluble / dispersible polymers are an optional ingredient that is preferred for inclusion in the liquid composition of the invention. Water-soluble / dispersible polymers may be cationic, anionic, amphoteric, or non-ionic polymers with a molecular weight greater than 100,000 Daltons. These polymers are known to improve the feel of the skin during and after use, enhance foam creaminess and stability, and increase the viscosity of liquid cleansing compositions. Examples of water-soluble / or water-dispersible structuring polymers useful in the present invention include carbohydrate gums such as cellulose gum, microcrystalline cellulose, cellulose gel, hydroxyethylcellulose, hydroxypropylcellulose, sodium carboxymethylcellulose, tapioca starch, citrus fibers, hydroxymethyl- or carboxymethylcellulose, methylcellulose, ethylcellulose, guar gum, karaya gum, tragacanth gum, gum arabic, acacia gum, agar gum, xanthan gum, and mixtures thereof; modified and unmodified starch granules with gelatinization temperatures between 30 and 85°C and pregelatinized cold water-soluble starch; polyacrylate; Carbopols; alkali-soluble emulsion polymers such as Aculyn 28, Aculyn 22, or Carbopol Aqua SF1; cationic polymer such as modified polysaccharides including cationic guar available from Rhone Poulenc under the trade name Jaguar C13S, Jaguar C14S, Jaguar C17 or Jaguar C16;Modified cationic cellulose such as UCARE Polymer JR 30 or JR 40 from Amerchol; N-Hance 3000, N-Hance 3196, N-Hance GPX 215 or N-Hance GPX 196 from Hercules; synthetic cationic polymer such as MerQuat 100, MerQuat 280, Merquat 281 and Merquat 550 from Nalco; cationic starches, for example, StaLok® 100, 200, 300 and 400 manufactured by the Galactasol 800 series from Henkel, Inc.; Quadrosoft L)m-200; and Polyquaternium-24. Preferably, the polymer comprises polysaccharide, polyacrylate or a mixture thereof; more preferably, the polymer is polysaccharide, polyacrylate or a mixture thereof. Gel-forming polymers such as modified or unmodified starch granules, xanthan gum, Carbopol, alkali-soluble emulsion polymers, and cationic guar gum such as Jaguar C13S, and modified cationic cellulose such as UCARE Polymer JR 30 or JR 40 are particularly preferred for this invention. Water-soluble skin-beneficial agents Water-soluble skin-beneficial agents are another optional ingredient that is preferred for inclusion in the liquid compositions of the invention. A variety of water-soluble skin-beneficial agents may be used, and the level may be from 0 to 40% by weight, preferably from 1 to 30%. Materials include, but are not limited to, polyhydroxy alcohols such as glycerol, propylene glycol, sorbitol, panthenol, and sugar; urea; alpha-hydroxy acids and their salts such as glycolic or lactic acid; and low-molecular-weight polyethylene glycols with a molecular weight of less than 20,000. The preferred water-soluble skin-beneficial agents for use in the liquid compositions are glycerol, sorbitol, and propylene glycol. The liquid cleaning composition of the invention may also comprise from 0 to 40% by weight of the beneficial agent. In another embodiment, from 0.01 to 15% by weight, and in yet another embodiment, from 0.02 to 10% by weight of the beneficial agent, based on the total weight of the composition and including all intervals therein. One type of ingredient is the nutrients used to hydrate and strengthen, for example, the skin. These include: a) vitamins such as vitamin A and E, and vitamin alkyl esters such as vitamin C alkyl esters; b) lipids such as cholesterol, cholesterol esters, lanolin, ceramides, sucrose esters and pseudoceramides; c) liposome-forming materials such as phospholipids and suitable amphophilic molecules having two long hydrocarbon chains; d) essential fatty acids, polyunsaturated fatty acids and sources of the same materials; e) unsaturated fatty acid triglycerides such as sunflower oil, evening primrose oil, avocado oil, almond oil; f) vegetable fats formed from mixtures of saturated and unsaturated fatty acids such as shea butter; g) minerals such as sources of zinc, magnesium and iron. A second type of skin-beneficial agent is a skin conditioner, which is used to provide a moisturizing sensation to the skin. Suitable skin conditioners include: a) Silicone oils, gums and modifications thereof such as linear and cyclic polydimethylsiloxanes, amino, alkyl and alkylaryl silicone oils; b) hydrocarbons such as liquid paraffins, petrolatum, petroleum jelly, microcrystalline wax, ceresin, squalene, pristan, paraffin wax and mineral oil; c) conditioning proteins such as milk proteins, silk proteins and glutens; d) Cationic polymers as conditioners that can be used include Quatrisoft LM-200 Polyquaternium-24, Merquat Plus 3330-Polyquaternium 30; and Jaguar® type conditioners; e) humectants such as glycerol, sorbitol and urea; f) emollients such as long-chain fatty acid esters, such as isopropyl palmitate and cetillactate. A third type of beneficial agent is the deep cleansing agent. These are defined as ingredients that can increase the feeling of freshness immediately after cleansing or provide a sustained effect on skin problems associated with incomplete cleansing. Deep cleansing agents include: a) antimicrobials such as 2-hydroxy-4,2',4'-trichlorodiphenyl ether (DP300), 2,6-dimet-4-hydroxychlorobenzene (PCMX), 3,4,4'-trichlorocarbanilide (TCC), 3-trifluoromethyl-4,4'-dichlorocarbanilide (TFC), benzoyl peroxide, zinc ribbons, tea tree oil, b) anti-acne agents such as salicylic acid, lactic acid, glycolic acid and citric acid, and benzoyl peroxide (also an antimicrobial agent), c) oil control agents including sebum suppressants, modifiers such as silica, titanium dioxide, oil absorbents such as microsponges, d) astringents, which include tannins, zinc and aluminum salts, plant extracts such as green tea and witch hazel (Hammailes), e) scrubbing and exfoliating particles, such as polyethylene spheres, agglomerated silica, sugar, ground earth, seeds and shells such as nuts, peach, avocado and oats, salts, f) refrigerants such as methanol and its various derivatives and lower alcohols, g) fruit and herb extracts, h) skin-relaxing agent such as aloe vera, i) essential oils such as mint, jasmine, camphor, white cedar, bitter orange peel, rye, turpentine, cinnamon, bergamot, unshiu citrus, calamus, pine, lavender, bay leaf, clove, hiba, eucalyptus, lemon, borage, thyme, spearmint, rose, sage, menthol, cineole, sugenol, citral, citronella, borneol, linalool, IVIA / a / ZUZ I 4UO0 geraniol, evening primrose, camphor, thymol, spirantol, pinene, limonene and terpenoid oils. Other beneficial agents that may be used include anti-aging compounds, sunscreens, and skin-brightening agents such as vitamin B3, resorcinols (especially 4-substituted resorcinols such as 4-ethyl- and 4-hexylresorcinol), retinoids, as well as antibacterial agents including terpineol and / or thymol. When the beneficial agent is oil, especially low-viscosity oil, it may be advantageous to thicken it beforehand to improve its release. In such cases, hydrophobic polymers of the type described in U.S. Patent No. 5,817,609 to He et al., which is incorporated by reference in this application, may be used. At room temperature, the composition contains surfactant crystals with a dissolution temperature between 30°C and 50°C. The compositions must also be physically stable in phase at room temperature and 45°C for at least two weeks. Other optional components Furthermore, the compositions of the invention may include from 0 to 10% by weight of optional ingredients as follows: Perfumes; sequestering agents, such as tetrasodium ethylenediaminetetraacetate (EDTA), HDPE or mixtures in an amount of 0.01 to 1%, preferably 0.01 to 0.05%; and coloring, opacifying and pearlizing agents such as zinc stearate, magnesium stearate, TIO₂, EGMS (ethylene glycol monostearate) or Lytron 621 (styrene / acrylate copolymer); all of which are useful for improving the appearance of the cosmetic properties of the product. The compositions may also include antimicrobials such as 2-hydroxy-4,2',4'-trichlorodiphenyl ether (DP300); preservatives such as dimethyldimethylhydantoin (Glydant XL 1000), parabens, sorbic acid, phenoxyethanol, iodopropynyl butylcarbamate, mixtures thereof, and the like. These preservatives may be enhanced with well-known preservative boosters such as 1,2-alkanediols, including 1,2-octanediol. Antioxidants such as, for example, butylated hydroxytoluene (BHT) can be used advantageously in amounts of approximately 0.01% or higher if appropriate. Polyethylene glycols that can be used as conditioners include: Polyox WSR-25 PEG 14M, Polyox WSR-N-60K PEG 45M, or Polyox WSR-N-750 PEG 7M. Other ingredients that can be included are exfoliants such as polyoxyethylene beads, walnut shells, and apricot seeds. The invention further comprises a method for preparing compositions comprising the components (1), (2), and (3) of the compositions indicated above, wherein the ratio of acyl isethionate to acyl methyl taurate is 1.5:1 to 1:1.5, preferably 1.25:1 to 1:1.25; wherein the ratio of amphoteric / zwitterionic surfactant to anionic surfactant is 1:1 and higher; and wherein the sum of surfactants is less than 20% by weight, the method comprising: 1) mix water and a structuring polymer up to approximately 75SC (70-80sC); 2) Add isethionate, taurate and optional fatty acid and mix until dissolved; 3) cool to 55°C and add amphoteric, zwitterionic and / or non-ionic; and 4) Adjust the pH to 5.0 to 7.4. The invention further comprises the use of compositions of the invention to improve foam. The compositions of the invention are isotropic, and an example of how to prepare them is also discussed in the protocol. Examples and protocol In all warranty examples, the foam was created using a Sita Foam device and the procedure is shown below. Various dilutions of the product with water were used, ranging from 2.5 grams of product to 250 grams of water to 10 grams of product to 250 grams of water, as consumers would use a range of product quantities in the shower and the dilution used in these examples approximates that range. Additionally, consumers may also rub the products onto their skin, either with their hand or a pad, with varying pressure, and to ensure consistency, some of the tests were conducted at two different agitation speeds. Sita Foam Tester R-2000 Procedure The Sita Foam Tester R-2000 was used to measure the foam generated under a specified dilution and shear rate. It uses a high-speed rotor that mixes the product with dilution water and creates a volume of foam. The rotor creates a vortex, which incorporates air, resulting in foam formation at different rates depending on the formulation's capacity. To operate the Sita Foam, the measurement parameters are found in the application under the "Device" drop-down menu. See the table below for the parameters used during these measurements. Parameter Serial Count Fill with Foam Buildup Measurement Stirring Counts Stirring Time Revolutions Medium Shear Test 1 250 mL 4 15s 1000 min1 High Shear Test 1 250 mL 4 15s 1500 min1 A heat exchanger must be connected to the Sita Foam glass container to ensure a constant temperature throughout the test. Set the heat exchanger to 38°C and wait 15 minutes for the temperature to reach 38°C. Temperature fluctuations in the heat exchanger between 37°C and 39°C are acceptable. Disperse 1 g, 2.5 g, 5 g, or 10 g of product into the Sita Foam glass container, ensuring the product does not rest on the sides of the container or the rotor, as this can cause inaccurate readings. Then, add water to the holding tank at the back of the Sita Foam. Adjust the water temperature to between 37°C and 39°C. This water will be used to dilute the product and generate foam. Begin the run with the Sita Foam. The Sita Foam will automatically dilute the product, then mix for 15 seconds. The run is mixed four times separately, taking a measurement between each reading. At least three readings must be taken for each unique sample at each desired dilution. Readings below 300 mL of foam generation should not be considered due to their susceptibility to error for a reliable evaluation. If the standard error at 2.5 g and 5 g is too high to discern the difference, increase the product dosage to 10 g, or change the parameters to those observed in the high shear test using 1 g of the product. Examples Isotropic formulations in general are discussed in Examples A to C below, and Examples 1-7 highlight mixtures of surfactant systems used in formulations A to C. Example A Isotropic (Compositions of Tables 1, 2, 3, 6 and 7) (Sodium Cocoylisethionate / Sodium Methylauryltaurate) Chemical % by weight typical range Water DI q.s.p.p.p.p. Synthalen W2000 0.60 0.60 Sodium cocoylisethionate 0.00 4.00 Sodium methyluroyltaurate 0.00 4.00 Stearic acid 0.05 0.05 Cocamidopropyl betaine 4.00 8.00 Glycerin 1.00 1.00 Tetrasodium EDTA 0.05 0.05 Phenoxyethanol 0.60 0.60 Iodopropynyl butylcarbamate 0.07 0.07 Sodium hydroxide 0.16 0.27 PPG-7 0.00 0.96 Example B Isotropic (compositions in Table 4) (sodium lauroylisethionate / sodium methyllauroyltaurate) Chemical % by weight typical range Water DI q.s.p.p.p. Synthalen W2000 0.60 0.60 Sodium lauroylisethionate 0.00 3.00 Sodium methyluroyltaurate 0.00 3.00 Stearic acid 0.05 0.05 Cocamidopropyl betaine 6.00 6.00 Glycerin 1.00 1.00 Tetrasodium EDTA 0.05 0.05 Phenoxyethanol 0.60 0.60 Iodopropynyl butylcarbamate 0.07 0.07 Sodium hydroxide 0.18 0.22 Citric acid 0.00 0.03 IVIA / a / ¿U¿ I 4UOO Example C Isotropic (Compositions in Table 5) (Sodium Cocoylisethionate / Sodium Methylcocoyltaurate) Chemical % by weight typical range Water DI q.s.p.p.p. Synthalen W2000 0.60 0.60 Sodium cocoylisethionate 0.00 3.00 Sodium methyl cocoyltaurate 0.00 3.00 Stearic acid 0.05 0.05 Cocamidopropyl betaine 6.00 6.00 Glycerin 1.00 1.00 Tetrasodium EDTA 0.05 0.05 Phenoxyethanol 0.60 0.60 Iodopropynyl butylcarbamate 0.07 0.07 Sodium hydroxide 0.18 0.21 Citric acid 0.00 0.03 Table 1 12% surfactants with lauroylmethyltaurate and cocoylisethionate; 2:1 amphoteric to anionic. Product dilution: 5.0g / 250mL, 1000 RPM; 2.5g / 250mL, 1000 RPM. Lauroylmethyltaurate / cocoylisethionate (wt% / wt%). Foam volume (mL) at 45 sec. STD error. Foam volume (mL) at 45 sec. STD error. 0.0% / 100.0% 549 16 343 8; 50.0% / 50.0% 664 3 555 9; 100.0% / 0.0% 569 8 534 4 Table 1: This formulation comprises 8% amphotericin (cocoamidopropylbetaine), 2% taurate, and 2% isethionate as shown in the model isotropic formula. The complete formulations are those shown in Examples A; complete formulations are used for foam testing. The best synergy occurs at 1:1 ratios. Methylacyltaurate-acylisethionate synergy exists at all tested 12% dilutions of the active body wash, and data indicate that criticality occurs at a ratio of 1.5:1 to 1:1.5, preferably 1.25:1 to 1:1.25, and most preferably at a 1:1 ratio of methylacyltaurate to acylisethionate. Table 2 Table 2: 9% surfactants with lauroylmethyltaurate and cocoylisethionate; 2:1 amphoteric to anionic Dilutions 5.0 g / 250 mL, 1000 RPM 2.5 g / 250 mL, 1000 RPM Lauroylmethyltaurate / cocoylisethionate (% wt / % wt) Foam volume (mL) at 45 sec. STD error Foam volume (mL) at 45 sec. STD error 0.0% / 100.0% 376 11 375 11 25.0% / 75.0% 447 18 374 6 40.0% / 60.0% 488 7 414 13 50.0% / 50.0% 537 14 519 2 60.0% / 40.0% 411 6 485 23 75.0% / 25.0% 398 11 372 1 100.0% / 0.0% 403 21 344 10 IVIAaZUZ Ί 4UO0 Table 2: This table contains 6% cocamidopropyl betaine, 1.5% methylacyltaurate, and 1.5% acylisethionate. The synergy between acylisethionate and methylacyltaurate is evident at 9% surfactants in both 2.5 g and 5.0 g dilutions. The absolute numbers are slightly lower than in Table 1 because there are 3% anions compared to 4% in Table 1. Synergy can be reliably observed between the acylisethionate to methylacyltaurate ratios of 60:40 and 40:60, as is evident from the data in the table above. Table 3 Table 3: 6% active surfactants with lauroylmethyltaurate and cocoylisethionate; 2:1 amphoteric to anionic Dilutions 5.0 g / 250 mL, 1000 RPM 5.0 g / 250 mL, 1000 RPM 2.5 g / 250 mL, 1000 RPM Cocoylmethyltaurate / Cocoylisethionate (% wt / % wt) Foam volume (mL) at 45 sec. STD error Foam volume (mL) at 45 sec. STD error Foam volume (mL) at 45 sec. Error STD 0.0% / 100.0% 409 2 458 15 Below limit Below limit 50.0% / 50.0% 569 21 468 14 Below limit Below limit 100.0% / 0.0% 494 25 434 19 Below limit Below limit Table 3: In this example, there is 4% cocamidopropyl betaine and 1% each of methylacyltaurate and acylisethionate. The synergy between methylacyltaurate and acylisethionate can be observed in formulations as low as 6% of the active surfactant, as previously mentioned. In this example, the standard error was high in the 5 g sample relative to the synergy differential, so a 10 g sample was required to reliably demonstrate the synergy. This is likely due to the low surfactant level in the samples, as indicated, which necessitates an additional product to increase the foam volume and, subsequently, the differentiation. The 2.5 g sample set was discarded according to our procedure because its reading was below the 300 mL foam volume requirement. Table 4 Table 4: 9% active surfactants with lauroylmethyltaurate and lauroylisethionate; 2:1 amphoteric to anionic. Dilutions: 5.0 g / 250 mL, 1000 RPM; 2.5 g / 250 mL, 1000 RPM. Lauroylmethyltaurate / cocoylisethionate (wt% / wt%). Foam Volume (mL) at 45 sec. STD Error. Foam Volume (mL) at 45 sec. STD Error. 0.0% / 100.0% 615 18 315 15; 50.0% / 50.0% 661 1 332 12; 100.0% / 0.0% 638 6 296 13 ML / a / ZUZ 1 4UO0 Table 4: The above data show that formulations using lauroyl grades of both methylacyltaurate and acylisethionate provide maximum foam-boosting synergy in a 1:1 range. The 2.5 g sample data are relatively flat due to the low foam volume, but are consistent with the invention. Table 5 Table 5: 9% active surfactants with cocoylmethyltaurate and cocoylisethionate; 2:1 amphoteric to anionic. Dilutions: 5.0 g / 250 mL, 1000 RPM; 2.5 g / 250 mL, 1000 RPM. Taurate / Isethionate (wt% / wt%) Foam Volume (mL) at 45 sec. STD Error. Foam Volume (mL) at 45 sec. STD Error. 0.0% / 100.0% 334 5 315 8; 50.0% / 50.0% 349 6 345 9; 100.0% / 0.0% 335 2 316 6 Table 5: The data indicate that formulations using cocoyl, methylacyltaurate, and acylisethionate grades exhibit maximum synergy in a 1:1 range. Table 6 Table 6: 9% surfactant, 2:1 amphoteric to anionic Dilutions 1.0 g / 250 mL, 1500 RPM Taurate / Isethionate (% wt / % wt) Foam volume (mL) at 45 sec. Standard Error 0.0% / 100.0% 475 4 50.0% / 50.0% 632 1 100.0% / 0.0% 459 6 Table 6: The synergy observed with 2.5 g and 5 g samples at 1000 RPM in Table 1 can also be observed with a 1 g sample at 1500 RPM. This sampling methodology has been shown to increase foam generation and, subsequently, sample differentiation within sample sets. Table 7 Table 7: 9% surfactant, 1.5:1 amphoteric to anionic dilutions 1.0 g / 250 mL, 1500 RPM Taurate / Isethionate (% wt / % wt) Foam volume (mL) at 45 sec. Standard error 0.0% / 100.0% 420 2 50.0% / 50.0% 453 10 100.0% / 0.0% 427 10 Table 7: Synergy exists at a 1:1 ratio when the amphoteric-to-anionic range is altered. This expression is achieved in this formulation, thus requiring high shear parameters and 1 g of product to show differentiation. Example C The compositions, consistent with this invention and comprising amine oxide, were prepared by mixing the following ingredients. Chemical % of active ingredient Water DI q.s. Synthalen W2000 0.60 Sodium cocoylisethionate 1.50 Sodium methyluroyltaurate 1.50 Stearic acid 0.05 Glycerin 1.00 Cocoamidopropylamine oxide 6.00 Tetrasodium EDTA 0.05 Phenoxyethanol 0.60 Iodopropylbutylcarbamate 0.007 Sodium hydroxide 0.016

Claims

1. An isotropic liquid composition characterized in that it comprises: 1) from 0.1 to 8%, preferably from 0.5 to 6%, more preferably from 1 to 4% by weight of acylisethionate; 2) from 0.1% to 8%, preferably from 0.5% to 6%, more preferably from 1% to 4% by weight of methylacyltaurate comprising lauroylmethyltaurate; 3) from 0.1 to 15%, preferably from 0.5 to 10% and more preferably from 1 to 8% by weight of an amphoteric / zwitterionic surfactant comprising cocamidopropylbetaine; 4) from 0.0 to 8.0%, preferably from 0.001 to 7%, and more preferably from 1 to 6% by weight of the nonionic surfactant, provided that the various surfactants of acylisethionate, methylacyltaurate comprising lauroylmethyltaurate, and amphoteric / zwitterionic surfactant comprising cocamidopropylbetaine are present in a lesser amount than any of the three surfactants indicated in 1), 2), and 3), provided that the sum of all surfactants is less than 20% by weight and the composition does not simultaneously comprise 0.01% by weight or more of the nonionic surfactant and 0.1% by weight or more of the amphoteric surfactant, including betaine, comprising cocamidopropylbetaine and / or zwitterionic surfactant, and does not simultaneously comprise 0.0% by weight of the amphoteric surfactant. and / or zwitterionic and 0.0% by weight of non-ionic surfactant, wherein the ratio of methylacylisethionate to isethionate is a surfactant between 1.5:1 to 1:1.

5. And more preferably, from 1.25:1 to 1:1.25, and more preferably, from 1.1:1 to 1:1.1, and more preferably, 1:1; and further wherein the composition comprises from 0 to 15% by weight, preferably from 0.01 to 15% by weight of glycerol, and more preferably, from 0.02 to 10% by weight of glycerol.

2. The composition according to claim 1, further characterized in that the pH is from 5.0 to 7.

4.

3. The composition according to claims 1 to 2, further characterized in that the amphoteric surfactant is cocamidopropyl betaine.

4. The composition according to any of the preceding claims, further characterized in that the weight ratio of the amphoteric, zwitterionic and / or nonionic to anionic surfactant is 1:1 and higher.

5. The composition according to any of the preceding claims, further characterized in that the non-ionic or amphoteric and / or zwitterionic to anionic components are in a weight ratio of 1:1 to 4:

1. 6.The composition according to any of the preceding claims, further characterized in that the ratio of the amphoteric, zwitterionic and / or nonionic surfactant to anionic surfactant is from 1.8:1 to 2.2:1 and the pH of the composition is from 5.0 to 7.4, preferably from 6.0 to 7.

3.

7. The composition according to any of the preceding claims, further characterized in that the pH is from 6.3 to 7.

3.

8. The composition according to any of the preceding claims, further characterized in that the amphoteric and / or zwitterionic surfactant constitutes from 0.0 to less than 0.1% by weight of the composition and the nonionic surfactant is present in an amount from 0.02 to 8% by weight of the composition.

9. The composition according to any of the preceding claims, further characterized in that the non-ionic surfactant is present in an amount of from 0.001 to 7% by weight of the composition. 10.The composition according to any of the preceding claims, further characterized in that the nonionic surfactant is cocamidopropylamine oxide.

11. Use of the composition according to claims 1 to 10 for enhanced foam washing.

12. A process for preparing compositions according to any of claims 1 to 10, characterized in that the process comprises: i. mixing water and a structuring polymer to produce a mixture and heating the mixture to approximately 75°C (70-80°C); ii. adding isethionate and taurate to the heated mixture and mixing until the isethionate and taurate are dissolved; iii. cooling the mixture to 55°C and adding the amphoteric, zwitterionic, and / or nonionic surfactant; and iv. adjusting the pH of the mixture to 5.0 to 7.4; v. recovering the composition; wherein the structuring polymer comprises polysaccharide, polyacrylate, or a mixture thereof. 13.The composition according to any of claims 1 to 10, further characterized in that the composition comprises less than 0.2% by weight of sulfate-based surfactant.