Alkyl amphoacetate surfactant having improved stability

Abstract

The present invention relates to an amphoacetate surfactant composition and the use thereof, as well as formulations comprising the amphoacetate surfactant composition.

Description

[0001] Alkyl amphoacetate surfactant having improved stability

[0002] This application claims priority to U.S. Provisional Patent Application 63 / 632,399, filed on April 10, 2024, the whole content of which is hereby incorporated herein by reference in its entirety for all purposes.

[0003] The present invention relates to an amphoacetate surfactant composition and the use thereof, as well as formulations comprising the amphoacetate surfactant composition.

[0004] Sodium lauroamphoacetate, a surfactant derived from coconut oil, has gained significant attention in various industries due to its versatile properties and applications.

[0005] One of the properties of sodium lauroamphoacetate, also known by its chemical formula CisTtw^NaOs, is acting as an amphoteric surfactant. Its molecular structure consists of a hydrophobic tail derived from lauric acid and a hydrophilic head. This unique structure imparts both detergent and foaming properties to the compound, which makes it suitable for a wide range of applications.

[0006] Sodium lauroamphoacetate generally serves as a versatile ingredient in various personal care and household products given its effective cleansing and foaming properties. In this respect, sodium lauroamphoacetate continues to play a valuable role in enhancing the performance and functionality of diverse consumer products and formulations.

[0007] According to EP 1988872 Al, alkylamphoacetates, such as sodium lauroamphoacetate, may be used in personal care applications, e.g., personal cleansing compositions. As indicated in EP 1988872 Al, alkylamphoacetates can improve product mildness and lather, and can improve the structure and stability of the compositions. The most commonly used alkylamphoacetates are lauroamphoacetate and cocoamphoacetate. However, alkylamphoacetates, including lauroamphoacetate and cocoamphoacetate, can have a high amount of salt, as well as impurities and unintended reaction products, which have a detrimental effect on the properties of the composition. In particular, traditional amphoacetate surfactants can have several wt.% of salt present (e.g., up to 8 wt.%, if not higher). For instance, commercially available sodium lauroamphoacetates that are sold in the personal care industry generally have high levels of salt (5-8 wt.%). This high level of salt can lead to detrimental properties, especially over long periods of time, elevated temperatures, or both. In particular, the high level of salt can contribute to significant discoloration (e.g., yellowing) and can contribute to significantly increasing the viscosity. High levels of salt can also cause compatibility issues with polymers in formulations, which therefore can affect the clarity, stability and performance of the overall formulation. In addition to high levels of salt, sodium lauroamphoacetate also has amidoamine, sodium glycolate and other compounds and by-products that tend to affect the properties over a long period of time and / or elevated temperatures, and can negatively impact the stability, including the long-term stability, of the surfactant. Due to these reasons, there exists a need for amphoacetate surfactants, including sodium lauroamphoacetate, that have improved long-term stability without undesirable discoloring and undesirable viscosity (e.g., high viscosity), while at the same time improves the performance and stability of formulations.

[0008] JP 2023062890 A describes a cleaning composition comprising an amphoteric surfactant, such as lauramidopropyl betaine, lauramidopropyl hydroxysultaine, and sodium lauroamphoacetate, with a low a salt concentration (sodium chloride, calcium chloride, and magnesium chloride). As desalination and purification methods for amphoteric surfactants, the reverse osmosis membrane method, the electrodialysis method, the ion exchange resin method, the solvent extraction method, and the recrystallization method are disclosed.

[0009] EP 1220886 Al relates to liquid cleansing compositions that are structured lamellar phase compositions. It is disclosed that the use of surfactants containing low salt levels enhances freeze / thaw stability in the structured liquid formulations.

[0010] EP 1988872 Al describes the problem that impurities or unintended reaction products, such as alkylamphodiacetate, in alkylamphoacetates, complicate maintaining acceptable stability, structure, lather and rheology in multiphase, personal care compositions.

[0011] Notwithstanding, the present invention relates to a more stable amphoacetate surfactant that can be obtained when the overall salt content is significantly reduced. The present invention also relates to a more stable amphoacetate surfactant that can be obtained when the overall salt content is significantly reduced, along with a reduction in the amount of sodium glycolate and amidoamines.

[0012] Thus, it is an object of the present invention to provide amphoacetate surfactants, including liquid amphoacetate surfactants, having low salt content (e.g., less than 0.5 wt.%) and better stability (e.g., no phase separation either with the amphoacetate or in formulations), and more preferably to provide sodium lauroamphoacetate that has improved shelf life and improves the performance and stability of formulations.

[0013] DETAILED DESCRIPTION OF THE INVENTION

[0014] Before the amphoacetate surfactant composition and the use thereof will be described in detail, it is to be understood that this invention is not limited to specific process conditions described herein, since such conditions may, of course, vary. It is also to be understood that the terminology used herein is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.

[0015] As used herein, the singular forms "a", "an", and "the" include both singular and plural referents unless the context clearly dictates otherwise. By way of example, "a compound" means one compound or more than one compound.

[0016] The terms "containing", "contains" and "contained of' as used herein are synonymous with "including", "includes" or " comprising", "comprises", and are inclusive or open-ended and do not exclude additional, non-recited members, elements or process steps. It will be appreciated that the terms “containing”, “contains”, "comprising", "comprises" and "comprised of as used herein comprise the terms "consisting of, "consisting essentially of ", "consists" and "consists of.

[0017] Throughout this application, the term "about" is used to indicate that a value includes the standard deviation of error for the device or method being employed to determine the value. As used herein, the terms “% by weight”, “wt.-%”, “wt%”, “weight percentage”, or “percentage by weight” are used interchangeably. The same applies to the terms “% by volume”, “vol.- %”, “vol. percentage”, or “percentage by volume”, or “% by mol”, “mol- %”, “mol percentage”, or “percentage by mol”.

[0018] As used herein, the term “formulation” preferably refers to the specific arrangement or combination of ingredients, components and additives in a product. It involves the process of designing and creating a mixture that achieves certain desired properties or functions. A formulation can be applied to various fields such as pharmaceuticals, cosmetics, home care, personal care, and more. In the context of dermatological products, a formulation involves the selection of active ingredients, excipients, preservatives and other additives to produce a stable, effective and safe product with desired properties such as texture, viscosity, stability and therapeutic efficacy.

[0019] As used herein, the term “composition” preferably refers to the make-up or ingredients of a substance or entity. It refers to the qualitative and quantitative arrangement of elements within a compound or mixture. In the context of dermatological products, composition refers to the ingredients present in a formulation. This includes active ingredients responsible for therapeutic effects as well as inactive ingredients such as excipients, preservatives, stabilizers, fragrances and other additives. The composition of a dermatological product plays a crucial role in determining its efficacy, safety, stability and skin compatibility.

[0020] As used herein, the term “dermatological” refers to anything related to the diagnosis, treatment, and prevention of disorders and conditions affecting the skin, hair, nails, and mucous membranes.

[0021] As used herein, the term “dermatological composition or formulation” refers preferably to a composition or formulation specifically designed for application on the skin to address various dermatological concerns. These compositions or formulations often contain active ingredients such as moisturizers, emollients, vitamins, antioxidants, anti-inflammatories, or medications tailored to treat conditions like acne, eczema, psoriasis, aging signs, or sun damage. Dermatological compositions come in various forms such as creams, lotions, gels, ointments, serums, or foams, formulated to penetrate the skin efficiently and deliver therapeutic or cosmetic benefits. As used herein, the term “pharmaceutical” refers preferably to a substance or product intended primarily for use in medicine to diagnose, treat or prevent disease or health conditions in humans or animals. Pharmaceuticals include a wide range of substances, including drugs, medicines, vaccines, biologies and various formulations designed to exert therapeutic effects on the body. These substances undergo rigorous research, development, testing and regulatory approval processes to ensure that safety, efficacy and quality standards are met before they are introduced into clinical practice or the marketplace.

[0022] The terms "cosmetic", "cosmetic composition", and "cosmetic formulation," unless otherwise stated, shall mean any substance or preparation intended to be placed in contact with the various external parts of the human body, including the epidermis, hair system, nails, and lips. "Cosmetics" may be placed with the intended purpose of cleaning, perfuming, beautifying, changing appearance and / or correcting odors and / or protecting or keeping the contacted portions of the human body in good condition.

[0023] The recitation of numerical ranges by endpoints includes all integer numbers and, where appropriate, fractions subsumed within that range (e.g. 1 to 5 can include 1, 2, 3, 4 when referring to, for example, a number of elements, and can also include 1.5, 2, 2.75 and 3.80, when referring to, for example, measurements). The recitation of end points also includes the end point values themselves (e.g. from 1.0 to 5.0 includes both 1.0 and 5.0). Any numerical range recited herein is intended to include all sub-ranges subsumed therein.

[0024] Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included to better appreciate the teaching of the present invention.

[0025] In the following passages, different alternatives, embodiments and variants of the invention are defined in more detail. Each alternative and embodiment so defined may be combined with any other alternative and embodiment, and this for each variant unless clearly indicated to the contrary or clearly incompatible when the value range of a same parameter is disjoined. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.

[0026] Furthermore, the particular features, structures or characteristics described in present description may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and from different embodiments, as would be understood by those in the art.

[0027] In a first embodiment, the invention is directed to an amphoacetate surfactant composition comprising: a) at least one amphoacetate or a salt thereof, preferably sodium lauroamphoacetate, b) less than 5.0 wt.-%, preferably less than 2.0 wt.-%, more preferably less than 1.0 wt.-%, more preferably less than 0.5 wt.-%, even more preferably less than 0.3 wt. % alkali metal chloride, based on the weight of the total composition.

[0028] Preferably, the amphoacetate surfactant composition further comprises: c) less than 1.0 wt.-%, preferably less than 0.1 wt.-%, of any amidoamine, based on the weight of the total composition.

[0029] Amidoamines are a class of organic compounds containing both an amine (-NH2) group and an amide (-CONH2) group in their molecular structure. These compounds find applications in various industries, including personal care, household products, and industrial processes, like coco amidoamine.

[0030] Preferably, in the amphoacetate surfactant composition the alkali metal is sodium.

[0031] Preferably, the amphoacetate surfactant composition further comprises: d) less than 1.0 wt.-%, preferably less than 0.6 wt.-%, more preferably less than 0.1 wt.-%, alkali metal glycolate, based on the weight of the total composition. A glycolate is preferably a salt or ester of glycolic acid.

[0032] Due to the reduced or absence of salt in the amphoacetate surfactant composition, an improved compatibility with polymers in formulations, including cosmetic, dermatological, pharmaceutical, personal care, hygiene, or similar formulations, can be preferably achieved. In this respect, improved compatibility with the polymers in the formulations means that the current amphoacetate surfactant compositions can be combined with polymers in formulations and the resulting formulations can demonstrate improved stability. For instance, the improved stability of the formulations can include improved optical properties of the formulations (e.g., the formulations are transparent with no visible incompatibility issues), as well as improved homogeneity of the formulations (e.g., the formulations demonstrate no phase separation or settling of the polymer or other compounds at 25°C - 45°C for about four (4) weeks or longer). Further, due to the reduced or absence of salt in the amphoacetate surfactant composition, the amphoacetate surfactant compositions of the present invention can have better color (e.g., lack of or limited yellowing or discoloration), especially over long periods of time, elevated temperatures, or both. Moreover, due to the reduced or absence of salt in the amphoacetate surfactant composition, the amphoacetate surfactant compositions of the present invention can have better viscosity (e.g., lack of elevated or increased viscosity), especially over long periods of time, elevated temperatures, or both.

[0033] With respect to polymers in the formulations, preferred polymers are selected from the group consisting of natural polymers like polysaccharides, gums, hydrolyzed proteins and synthetic polymers like polyacrylates copolymers, methyl acrylate copolymers and other homo and copolymers.

[0034] In certain embodiments, the amphoacetate surfactant composition preferably does not contain any alkali metal chloride, any amidoamine, any alkali metal glycolate, or combinations thereof.

[0035] Preferably, in the amphoacetate surfactant composition, the a) at least one amphoacetate or a salt thereof is of formula (I): wherein R1 is a linear or branched C2-C2o-alkyl, and M+is an alkali metal cation, preferably Na+. As used herein, the term “alkyl” means a monovalent saturated or unsaturated straight chain, branched or cyclic hydrocarbon radical, typically a monovalent saturated hydrocarbon radical. Preferably, the term “alkyl” means a monovalent saturated straight chain, branched or cyclic hydrocarbon radical, typically a monovalent saturated (C2 - C20 or C2 - C20) hydrocarbon radical, such as for example, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, t-butyl, pentyl, n- hexyl, cyclohexyl, and cyclooctyl, which may optionally be substituted on one or more of the carbon atoms of the radical. In one embodiment, an alkyl radical is substituted on one or more carbon atoms of the radical with hydroxy, alkoxy, amino, halo, carboxy, or phosphono, such as, for example, hydroxymethyl hydroxyethyl, methoxymethyl, ethoxymethyl, isopropoxyethyl, aminomethyl, chloromethyl or tri chloromethyl.

[0036] In particular, alkyl is selected from C2-C20, preferably C6-C14 chains. For example, the alkyl chain is selected from:

[0037] C2 as ethyl,

[0038] C3 alkyl chain, for example propyl (e.g., n-propyl and isopropyl), C4 alkyl chain, for example butyl (e.g., n-butyl, isobutyl, t-butyl), C5 alkyl chain, for example pentyl (e.g., n-pentyl, isopentyl, neopentyl), C6 alkyl chain, for example n-hexyl, 2-methyl-pentyl, 3-methyl-pentyl, 2,2- dimethyl-butyl, 2,3-dimethyl-butyl,

[0039] C7 alkyl chain, for example n-heptyl, 2-m ethylhexyl, 3 -methylhexyl, 2,2- dimethylpentyl, 2,3 -dimethylpentyl, 2,4-dimethylpentyl, 3, 3 -dimethylpentyl, 3- ethylpentyl, 2,2, 3 -trimethylbutyl,

[0040] C8 alkyl chain, for example n-octyl, 2-m ethylheptyl, 3 -methylheptyl, 4- methylheptyl, 2,2-dimethylhexyl, 2,3-dimethylhexyl, 2,4-dimethylhexyl, 2,5- dimethylhexyl, 3, 3 -dimethylhexyl, 3,4-dimethylhexyl, 3 -ethylhexyl, 2,2,3- trimethylpentyl, 2,2,4-trimethylpentyl, 2, 3, 3 -trimethylpentyl, 2,3,4- trimethylpentyl, 2-m ethyl-3 -ethylpentyl, 3 -methyl-3 -ethylpentyl, 2, 2,3,3- tetramethylbutyl,

[0041] C9 alkyl chain, for example n-nonyl, 2-Methyloctyl, 3 -methyloctyl, 4- methyloctyl, 2,2-dimethylheptyl, 2,3-dimethylheptyl, 2,4-dimethylheptyl, 2,5- dimethylheptyl, 2,6-dimethylheptyl, 3,3-dimethylheptyl, 3,4-Dimethylheptyl, 3,5-Dimethylheptyl, 4,4-Dimethylheptyl, 3 -ethylheptyl, 4-ethylheptyl, 2,2,3- trimethylhexyl, 2,2,4-trimethylhexyl, 2,2,5-trimethylhexyl, 2,3,3-trimethylhexyl, 2,3,4-trimethylhexyl, 2, 3, 5 -trimethylhexyl, 2,4,4-trimethylhexyl, 3,3,4- trimethylhexyl, 3 -ethyl-2 -methylhexyl, 4-ethyl-2 -methylhexyl, 3-ethyl-3- methylhexyl, 3 -ethyl-4-m ethylhexyl, 2,2,3,3-tetramethylpentyl, 2, 2,3,4- tetramethylpentyl, 2,2,4,4-tetramethylpentyl, 2,3,3,4-tetramethylpentyl, 3-ethyl- 2,2-dimethylpentyl, 3-ethyl-2,3-dimethylpentyl, 3 -ethyl-2, 4-dimethylpentyl, 3,3- diethylpentyl,

[0042] C10-C20 alkyl chain, for example n-decyl, isodecyl, undecyl, isoundecyl, dodecyl, isododecyl, tridecyl, isotridecyl, tetradecyl, isoetradecyl, pentadecyl, isopentadecyl, hexadecyl, isohexadecyl, octadecyl.

[0043] Preferably, in the inventive amphoacetate surfactant composition, the amount of alkali metal chloride is less than 5.0 wt.-%, preferably less than 2.0 wt.-%, more preferably less than 1.0 wt.-%, even more preferably less than 0.3 wt.-%, most preferably less than 0.1 wt. %, based on the weight of the total composition. In certain embodiments, the amphoacetate surfactant composition having the reduced or absence of alkali metal chloride can be obtained by filtration of the at least one amphoacetate or a salt thereof. Preferably, the alkali metal chloride is sodium chloride.

[0044] Preferably, the amphoacetate surfactant composition comprises: a) 0.01 to 95 wt.-%, preferably 10 to 50 wt.-%, more preferably 20 to 40 wt.- %, of sodium lauroamphoacetate, and b) optionally 5 to 99.99 wt.-%, preferably 50 to 90 wt.-%, more preferably 60 to 80 wt.-% of water.

[0045] In preferred embodiments, the amphoacetate surfactant composition comprises sodium lauroamphoacetate from 0.01 to 95 wt.-%, preferably 10 to 50 wt.-%, more preferably 24 to 40 wt.-%, of the sodium lauroamphoacetate with the remaining amount being water (i.e., water up to 100% of the composition).

[0046] Preferably, the amphoacetate surfactant composition has a viscosity from 10 to 500, preferably from 50 to 250, more preferably 50 to 100, referring to the standard of 5000 max cps at 25°C. The viscosity is measured using a Brookfield viscometer spindle LV#3 @ 20 rpm (25°C).

[0047] Preferably, the amount of solids in the amphoacetate surfactant composition is less than 35.0 wt.-%, preferably less than 32.0 wt.-%, more preferably between 22.0 and 32 wt.-%, based on the total weight of the composition. The solids are measured on a CEM microwave solids analyzer. The measurement is done at 105°C.

[0048] Preferably, the amphoacetate surfactant composition is a liquid composition. Further, preferably the amphoacetate surfactant composition is an aqueous composition (e.g., in which water serves as the primary solvent or medium).

[0049] In certain embodiments, the amphoacetate surfactant composition can be in a solution, suspension, emulsion or colloidal dispersion, depending on the specific formulation.

[0050] Preferably, the amphoacetate surfactant composition can have a pH ranging from 9 - 13, preferably from 9.5 -13, more preferably from 10.5 - 13, even more preferably from 11 - 12. In other embodiment, the amphoacetate surfactant composition can have a pH ranging from 7 - less than 10.5, preferably 7.5 - 10.

[0051] Preferably, for amphoacetate surfactant composition the value for the Color Gardner Scale is 3 or less, preferably from 1 to 3, more preferably from 1 to 1.5. In certain embodiments, the value for the Color Gardner Scale is 3 or less, preferably from 1 to 3, more preferably from 1 to 1.5 and the Color Gardner Scale value for the amphoacetate surfactant composition does not increase over a Color Gardner Scale value of greater than 3 for at least four (4) weeks after production of the amphoacetate surfactant composition at room temperature, and preferably does not increase over a Color Gardner Scale value of greater than 3 for at least four (4) weeks after production of the amphoacetate surfactant composition at 45°C. In other embodiments, the amphoacetate surfactant composition can have a value for the Color Gardner Scale of 3 or less, preferably from 1 to 3, more preferably from 1.0 to 1.5 for at least four weeks at 45°C after production of the amphoacetate surfactant composition. The Color Gardner measurements are done using the BYK spectrophotomer.

[0052] The Color Gardner Scale, also known as the Gardner Color Scale or Gardner Color Index, is a method used to quantify the color of liquids, particularly those used in industrial applications such as paints, varnishes, and chemicals. It is named after its inventor, Robert S. Gardner. The Gardner Color Scale typically ranges from 1 to 18, with each value corresponding to a specific color intensity or darkness. The scale is based on visual comparison of the sample to a set of colored glass standards. These standards are arranged in a series from light to dark, with each standard assigned a Gardner color number:

[0053] Gardner Color Numbers 1-3 : These values represent very light or near water- white liquids, indicating minimal coloration.

[0054] Gardner Color Numbers 4-8: These values represent light-colored liquids with slight coloration, typically ranging from pale yellow to light amber.

[0055] A further embodiment of the invention is directed to the use of the inventive amphoacetate surfactant composition in cosmetic, dermatological, pharmaceutical, personal care, hygiene, or similar formulations, as well as such formulations comprising the amphoacetate surfactant composition.

[0056] For example, the cosmetic composition or formulation of the invention may be a topical composition or formulation which can be formulated as a suspension (e.g., a liposomal suspension), emulsion, nano-emulsion, hydrogel, multiphase solution, liposomal dispersion, lotion, cream, gel, essence, foam, liquid, cake, ointment, paste, serum, spray, aerosol, conditioner, shampoo, mask, cleanser, tonic, makeup (e.g., lipstick, foundation, bronzer, rouge, eyeshadow), patch, pencil, powder, towelette, soap, cleanser, stick, mousse, elixir, concentrate and / or after-shave.

[0057] In particular, the amphoacetate surfactant compositions of the present invention can be used in cosmetic, dermatological, pharmaceutical, personal care, hygiene, or similar formulation, in which the formulations are applied to the hair, skin, nails, or combinations thereof. For example, the compositions can be used in formulations by applying the formulations to an area of skin, hair, or nails on a body; washing the area of skin, hair, or nails on the body; and rinsing the area of skin, hair, or nails on the body.

[0058] Preferably, the amphoacetate surfactant composition may comprise additional cosmetic ingredients. These components may be considered active ingredients or inactive ingredients, and can be categorized by the benefit they provide or by their postulated mode of action; however, it is to be understood that the additional components can in some instances provide more than one benefit or operate via more than one mode of action. Therefore, classifications herein are made for the sake of convenience and are not intended to limit the agent to that particular application or applications listed.

[0059] Examples of such cosmetic ingredient classes include: organic solvents, silicones, pH adjusters, chelating agents, gelling agents, proteins, vitamins, emollients, oils, hydroxy acids, exfoliants, retinoids, viscosity modifiers, polymers, minerals, insect repellents, lubricants, preservatives, botanicals, clarifying agents, humectants, non-biological surfactants, antioxidants, thickeners, softeners, sunscreens, moisturizers, dyes, colorants, fragrances, abrasives, absorbents, aesthetic components such as essential oils, skin sensate, astringents, anti-acne agents, anti-caking agents, antifoaming agents, antimicrobial agents, depigmenting agents, anti-inflammatory agents, advanced glycation end-product (AGE) inhibitors, steroids, binders, biological additives, buffering agents, bulking agents, chelating agents, chemical additives, denaturants, external analgesics, keratolytic agents, desquamating agents, keratinocyte proliferation enhancers, collagenase inhibitors, elastase inhibitors, film formers or materials, opacifying agents, propellants, reducing agents, enzymes, sequestrants, skin bleaching and lightening agents, skin-conditioning agents, skin soothing and / or healing agents, thickeners, minerals, vitamins and derivatives thereof.

[0060] Preferably, for the inventive use in a formulation, the formulation comprises:

[0061] A) greater than 0 wt.-% and up to 20 wt.-% of the inventive amphoacetate surfactant composition,

[0062] B) optionally greater than 0 wt.-%, preferably greater than 0.0001 wt.-%, and up to 95 wt.-% water,

[0063] C) optionally greater than 0 wt.-%, preferably greater than 0.0001 wt.-%, and up to 5 wt.-% solubilizer,

[0064] D) optionally greater than 0 wt.-%, preferably greater than 0.0001 wt.-%, and up to 2.5 wt.-% surfactant, wherein the surfactant is different from the amphoacetate surfactant in A),

[0065] E) optionally greater than 0 wt.-%, preferably greater than 0.0001 wt.-%, and up to 2.5 wt.-% thickener, and

[0066] F) optionally greater than 0 wt.-%, preferably greater than 0.0001 wt.-%, and up to 2.5 wt.-% preservative, wherein the amounts of A) to F) sum up to 100 wt.-%.

[0067] More preferably, for the inventive use in a cosmetic formulation, the cosmetic formulation comprises: A) from 0.001 wt.-% to 20 wt.-% of the inventive amphoacetate surfactant composition,

[0068] B) from 0.001 wt.-% to 95 wt.-% water,

[0069] C) from 0.001 wt.-% to 5 wt.-% solubilizer,

[0070] D) from 0.001 wt.-% to 2.5 wt.-% surfactant, wherein the surfactant is different from the amphoacetate surfactant in A),

[0071] E) from 0.001 wt.-% to 2.5 wt.-% thickener, and

[0072] F) from 0.001 wt.-% to 2.5 wt.-% preservative, wherein the amounts of A) to F) sum up to 100 wt.-%.

[0073] Commonly encountered surfactant components include various anionic surfactants, especially the alkyl benzene sulfonates, alkyl sulfates, alkyl alkoxy sulfates, amino acid based surfactants such as glycinates, taurates, sarcosinates, glutamates and various nonionic surfactants, such as alkyl ethoxylates and alkylphenol ethoxylates. Surfactants have found use as detergent components capable of the removal of a wide variety of soils and stains.

[0074] Commonly encountered solubilizer such as PEG- 40 hydrogenated castor oil, polysorbate 20 and polysorbate 80, PEG-7 glyceryl cocoate.

[0075] Commonly encountered thickener such as gums, acrylates copolymers, guars, xanthan gum, high alkyl chain surfactants.

[0076] Commonly encountered preservative such as phenoxyethanol, benzyl alcohol, Sodium benzoate

[0077] Examples

[0078] The Comparative Example 1 is a commercially available sodium lauroamphoacetate surfactant available from Syensqo. Example 1 is the same sodium lauroamphoacetate surfactant used in Comparative Example 1; however, the sodium lauroamphoacetate was filtered by nanofiltration.

[0079] The Comparative Example 2 is a commercially available sodium lauroamphoacetate surfactant available from Syensqo. Example 2 is the same sodium lauroamphoacetate surfactant used in Comparative Example 2; however, the sodium lauroamphoacetate was filtered by nanofiltration. Table 1

[0080] In Table 1 it can be seen that the value of the Color Gardner and the viscosity of Example 1 is superior in comparison to Comparative Example 1.

[0081] Table 2

[0082] As demonstrated in Table 2, the sodium lauroamphoacetate of Example 2 having lower amounts of salt (i.e., sodium chloride), along with lower amounts of sodium glycolate and amidoamine has exceptionally better color after aging for four (4) weeks at 45°C. Further, the sodium lauroamphoacetate of Example 2 having the lower amounts of sodium chloride, sodium glycolate and amidoamine not only has a significantly lower initial viscosity, but the viscosity does not significantly increase after aging for four (4) weeks at 45°C. In contrast, Comparative Example 2 having the higher amounts of sodium chloride, sodium glycolate and amidoamine not only has a significantly higher initial viscosity as compared to Example 2, but the viscosity of Comparative Example 2 increases significantly after aging for four (4) weeks at 45°C. Without being bound to any theory, surprisingly the amounts of sodium chloride, sodium glycolate and amidoamine significantly impacts the color and viscosity, especially after aging at elevated temperatures. This also impacts the long-term stability of the sodium lauroamphoacetate, especially at elevated temperatures. Unexpectedly, when the overall salt content of the amphoacetate surfactant is significantly reduced (e.g., less than 0.5 wt.%), the color and viscosity can be significantly improved, especially at elevated temperatures.

Claims

Claims1. An amphoacetate surfactant composition comprising: a) at least one amphoacetate or a salt thereof, b) less than 5.0 wt.-% alkali metal chloride, based on the weight of the total composition.

2. The amphoacetate surfactant composition according to claim 1, further comprising: c) less than 1.0 wt.-% of any amidoamine, based on the weight of the total composition.

3. The amphoacetate surfactant composition according to claim 1 or 2, wherein the alkali metal is sodium.

4. The amphoacetate surfactant composition according to any of the claims 1 to 3, further comprising: d) less than 1.0 wt.-% alkali metal glycolate, based on the weight of the total composition.

5. The amphoacetate surfactant composition according to any of the claims 1 to 4, wherein the amphoacetate surfactant composition does not contain any alkali metal chloride, any amidoamine, any alkali metal glycolate, or combinations thereof.

6. The amphoacetate surfactant composition according to any of the claims 1 to 5, wherein the a) at least one amphoacetate or a salt thereof is of formula (I):wherein R1 is a linear or branched C2-C2o-alkyl, and M+is an alkali metal cation.

7. The amphoacetate surfactant composition according to any of the claims 1 to 6, wherein the amount of less than 5.0 wt.-% alkali metal chloride, based on the weight of the total composition, is obtained by filtration of the at least one amphoacetate or a salt thereof.

8. The amphoacetate surfactant composition according to any of the claims 1 to 7, wherein the amphoacetate surfactant composition comprises: a) 0.01 to 95 wt.-% of sodium lauroamphoacetate, and b) optionally 5 to 99.99 wt.-% of water.

9. The amphoacetate surfactant composition according to any of the claims 1 to 8, wherein the composition has a viscosity from 10 to 500, referring to the standard of 5000 max cps at 25°C.

10. The amphoacetate surfactant composition according to any of the claims 1 to 9, wherein the amount of solids in the composition is less than 35.0 wt.-%, based on the total weight of the composition.

11. The amphoacetate surfactant composition according to any of the claims 1 to 10, wherein the amphoacetate surfactant composition is an aqueous composition.

12. The amphoacetate surfactant composition according to any of the claims 1 to 11, wherein the amphoacetate surfactant composition is a liquid composition.

13. The amphoacetate surfactant composition according to any of the claims 1 to 12, wherein the amphoacetate surfactant composition has a pH ranging from 9 - 13, preferably 10.5 - 13.

14. The amphoacetate surfactant composition according any of the claims 1 to 13, wherein the value for the Color Gardner Scale is 3 or less.

15. A formulation comprising the amphoacetate surfactant composition according any of the claims 1 to 14.

16. The formulation according to claim 15, wherein the formulation is a cosmetic, dermatological, pharmaceutical, personal care, hygiene, or similar formulation.

17. Use of the amphoacetate surfactant composition according to any of the claims 1 to 14 in cosmetic, dermatological, pharmaceutical, personal care, hygiene, or similar formulations.

18. The use according to claim 17, in a formulation, wherein the formulation comprises:A) greater than 0 wt.-% and up to 20 wt.-% of the amphoacetate surfactant composition according to any of the claims 1 to 12,B) optionally greater than 0 wt.-% and up to 95 wt.-% waterC) optionally greater than 0 wt.-% and up to 5 wt.-% solubilizerD) optionally greater than 0 wt.-% and up to 2.5 wt.-% surfactantE) optionally greater than 0 wt.-% and up to 2.5 wt.-% thickenerF) optionally greater than 0 wt.-% and up to 2.5 wt.-% preservative.

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