Green thickening composition containing nicotinamide and application thereof

Abstract

The invention discloses a green thickening composition containing nicotinamide and application of the green thickening composition. The green thickening composition comprises (a) salt of N-long-chain acyl amino acid, (b) free N-long-chain acyl amino acid, (c) hydrophilic nonionic surfactant, (d) alkyl glycoside and (e) nicotinamide, related green thickening compositions can be used to prepare personal care articles.

Description

Technical Field

[0001] This invention relates to the field of thickening technology, and particularly to green thickening compositions containing nicotinamide, and their application in various personal care products. Background Technology

[0002] With increasing global environmental awareness and a growing emphasis on sustainable development, the daily chemical industry is gradually transforming towards green manufacturing, and the greening of raw materials is a crucial part of this process. Daily chemical companies are increasingly adopting renewable raw materials, such as plant extracts, marine biological resources, and naturally derived ingredients, to replace traditional chemical raw materials.

[0004] Niacinamide, also known as vitamin B3, vitamin PP, or nicotinamide, is a type of B vitamin. Niacinamide can accelerate metabolism, promote the shedding of melanin-containing keratinocytes, act on existing melanin to reduce its transfer to surface cells, promote the synthesis of epidermal proteins, and improve skin texture. Topical application can reduce the production of fatty acids and triglycerides in sebum, thereby minimizing pores and reducing the severity of acne.

[0005] Niacinamide boasts a variety of benefits, including whitening, moisturizing, repairing, oil control, and anti-wrinkle properties, making it a core ingredient in the formulas of many well-known domestic and international brands. A 2% concentration provides significant moisturizing and repairing effects, replenishing skin moisture and strengthening its barrier function. At a 3% concentration, niacinamide not only improves skin texture but also brightens and whitens the skin. A 5% concentration offers even more potent and noticeable whitening effects, effectively reducing pigmentation.

[0006] However, the addition of nicotinamide to a formulation system can easily cause a significant decrease in viscosity of water-based or emulsion systems, even leading to a thinning or watery consistency. The main reasons for this viscosity decrease are as follows.

[0007] ① Electrolyte effect: Nicotinamide is a water-soluble vitamin that slightly ionizes in solution and has a certain ionic strength. It is an electrolyte.

[0008] ② Disruption of thickening structure: Many commonly used aqueous thickeners (such as carbomer and acrylic (ester) copolymers) thicken through hydrogen bonding, electrostatic repulsion, or the formation of a three-dimensional network structure between molecular chains. The addition of electrolytes compresses the ionic double layer around the thickener molecular chains, neutralizes the charge, and causes the molecular chains to curl up, disrupting their hydration and network structure, thereby causing a sharp drop in viscosity (i.e., "salt breakdown" or "poor ion resistance").

[0009] ③ Competitive hydrogen bonds: Nicotinamide molecules themselves contain amide groups and pyridine nitrogen, which can form strong hydrogen bonds with water molecules. This may compete with some thickeners (such as cellulose and xanthan gum) for water binding, thereby weakening the hydration effect of the thickener and affecting the thickening efficiency.

[0010] Amino acid surfactants are notoriously difficult to thicken. Currently, the main methods for thickening amino acid surfactants include: 1) using polymer thickeners, such as acrylate copolymers and cellulose compounds; 2) compounding nonionic (e.g., fatty alcohols, fatty acids, alkanolamides, alkyl glycosides), cationic, and amphoteric surfactants (e.g., betaines); 3) adding natural gums and their modifiers, such as carrageenan, guar gum, and xanthan gum. Each of these thickening methods has its own problems. Using polymer thickeners can lead to issues such as discoloration at high temperatures, jelly-like phenomena at low temperatures, reduced foaming effect and user experience, and a slippery feel after rinsing. Furthermore, high-molecular-weight polymers typically require very high concentrations to achieve the desired thickening effect. Compounding with other surfactants for thickening currently focuses on conventional alkanolamides, alkyl glycosides, and betaines, but the thickening effect is limited, resulting in a cloudy, opaque (foggy) appearance, and viscosity decreases over long-term storage. Gum-like substances are not only difficult to dissolve, but excessive amounts can also cause jelly-like phenomena, stringiness, and poor rheological properties.

[0011] Thickening formulations using amino acid surfactants combined with nicotinamide becomes significantly more challenging. The inventors have already developed a formulation system that uses free N-long-chain acyl amino acids, combined with hydrophilic nonionic surfactants and amphoteric surfactants, for synergistic thickening. However, considering that the natural source index of the amphoteric surfactant betaine is below 0.8, while that of alkyl glycosides is 1, replacing betaine with alkyl glycosides would effectively increase the overall natural source content of the formulation. Summary of the Invention

[0012] The inventors' team constructed a thickening system containing (a) a salt of N-long-chain acyl amino acids, (b) free N-long-chain acyl amino acids, (c) a hydrophilic nonionic surfactant, and (d) an alkyl glycoside for thickening (e) nicotinamide.

[0013] Specifically, the present invention provides the following technical solution.

[0014] The present invention provides a green thickening composition containing nicotinamide, comprising (a) a salt of N-long-chain acyl amino acid, (b) free N-long-chain acyl amino acid, (c) a hydrophilic nonionic surfactant, (d) an alkyl glycoside, and (e) nicotinamide.

[0015] Alternatively, the green thickening composition containing nicotinamide comprises (a') an N-long-chain acyl amino acid partially neutralized with an alkali, (c) a hydrophilic nonionic surfactant, (d) an alkyl glycoside, and (e) nicotinamide. Wherein, (a') the N-long-chain acyl amino acid partially neutralized with an alkali refers to the product of the partial neutralization of the N-long-chain acyl amino acid with an alkali, the product ultimately present in the composition as a salt of the N-long-chain acyl amino acid and unneutralized free N-long-chain acyl amino acid.

[0016] Alternatively, the green thickening composition containing nicotinamide comprises (a'') a base and an N-long-chain acyl amino acid, wherein the molar number of the base is less than that of the N-long-chain acyl amino acid, resulting in a neutralization degree of less than 100% for the N-long-chain acyl amino acid; (c) a hydrophilic nonionic surfactant; (d) an alkyl glycoside; and (e) nicotinamide. Although the base and the N-long-chain acyl amino acid are added to the formulation separately, they inevitably react. Due to the neutralization degree being less than 100%, what ultimately exists in the composition are the salts of the N-long-chain acyl amino acid and unneutralized free N-long-chain acyl amino acids.

[0017] The composition may also include, as needed, carriers, additives, active ingredients, water, etc., acceptable in the field of personal care products.

[0018] For N-long-chain acyl amino acids, a natural source index greater than 0.5 and less than or equal to 1 indicates a green component. The N-long-chain acyl group in the N-long-chain acyl amino acid originates from saturated or unsaturated straight-chain or branched fatty acids with 8 to 22 carbon atoms. Further, the N-long-chain acyl group in the N-long-chain acyl amino acid is selected from one or more of octanoyl, decanoyl, undecanoyl, lauroyl, myristoyl, pentadecanoyl, palmitoyl, stearoyl, oleoyl, linoleoyl, isostearoyl, coconut oil fatty acyl, and palm oil fatty acyl, preferably coconut oil fatty acyl or lauroyl, with lauroyl being the most preferred.

[0019] The amino acids in the N-long-chain acyl amino acids are derived from one or more of glycine, alanine, glutamic acid, sarcosine, aspartic acid, leucine, isoleucine, valine, threonine, proline, phenylalanine, arginine, lysine, and (methyl)taurine. Further, the amino acids in the N-long-chain acyl amino acids are derived from one or more of alanine, glycine, glutamic acid, sarcosine, arginine, lysine, and (methyl)taurine, preferably alanine, and most preferably L-alanine. The N-long-chain acyl (methyl)taurine described in this invention refers to N-long-chain acylmethyl taurine or N-long-chain acyl taurine.

[0020] As an example, N-long-chain acyl amino acids can be selected from cocoyl alanine, lauroyl alanine, cocoyl sarcosine, lauroyl sarcosine, lauroyl glutamic acid, cocoyl glutamic acid, oleyl glutamic acid, cocoyl glycine, lauroyl glycine, stearoyl glutamic acid, etc.

[0021] This invention reveals that N-long-chain acyl amino acids with different structures exhibit varying thickening abilities. Free N-long-chain acylglutamic acid has a weaker thickening effect than its counterparts, N-long-chain acylalanine, glycine, and sarcosine. N-long-chain acylglycine possesses good thickening ability, but its formulation is prone to precipitation and exhibits poor stability, making it suitable for paste-like products where high transparency is not required. The surprising discovery of this invention is that, under the same formulation conditions, lauroylalanine's thickening ability far surpasses that of other long-chain acyl amino acids, being 5-10 times stronger than similarly structured lauroylsarcosine and cocoylalanine (cocoylaminopropionic acid).

[0022] Furthermore, based on ISO 16128 or T / SHRH 041-2022 standards, the natural source index of lauroyl sarcosine, cocoyl glycinate, methyl taurine, etc., is less than 0.8, while the natural source index of lauroyl alanine reaches 1. If the N-long chain acyl amino acid is chosen as lauroyl alanine, the natural source content of the formula can be significantly increased.

[0023] (a) A salt of an N-long-chain acyl amino acid refers to a salt formed by an N-long-chain acyl amino acid and a base. The base is selected from one or more of inorganic bases, organic amines, and basic amino acids. The inorganic base is selected from one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate, preferably sodium hydroxide or potassium hydroxide. The organic amine is selected from amines, alkanolamines, etc. For basic amino acids, it is selected from one or more of arginine, lysine, citrulline, ornithine, creatine, histidine, diaminobutyric acid, and diaminopropionic acid, preferably arginine and / or lysine, and most preferably L-arginine. The bases described in (a') and (a'') also have the same definition. Considering that the natural source index of arginine and lysine reaches 1, the present invention particularly prefers arginine and lysine as the base.

[0024] N-long-chain acyl amino acids can be directly mixed into commercially available long-chain acyl amino acid salts such as Puji's YB02-30 (sodium cocoylaminopropionate), AS02-30 (sodium lauroyl sarcosinate), Tianci's AMIN LS30 (sodium lauroyl sarcosinate), Suzhou Weimei's LA-Arg 30 (lauroyl alanine arginine salt), and LA-Na 30 (sodium lauroyl alanine), or N-long-chain acyl amino acids can be directly mixed into a formulation containing (a) N-long-chain acyl amino acid salts to obtain (a) N-long-chain acyl amino acid salts and (b) free N-long-chain acyl amino acids.

[0025] Alternatively, N-long-chain acyl amino acids can be partially neutralized with a base to obtain (a') N-long-chain acyl amino acids partially neutralized with a base. Alternatively, a base and an N-long-chain acyl amino acid can be added to the formulation separately (corresponding to (a'')). Since the base is used for partial neutralization and the N-long-chain acyl amino acid is in excess, the system will contain both the neutralized N-long-chain acyl amino acid salt and the unneutralized free N-long-chain acyl amino acid, which is essentially equivalent to (a) the salt of the N-long-chain acyl amino acid + (b) the free N-long-chain acyl amino acid.

[0026] The synthesis process of N-long-chain acyl amino acid surfactants can refer to the general synthesis methods of N-acyl amino acid type surfactants, and is divided into direct methods and indirect methods. Direct synthesis methods from fatty acid raw materials include enzyme-catalyzed synthesis and dehydration condensation. Indirect synthesis methods include acylation of fatty acid acyl chlorides, hydrolytic acylation of fatty acid nitriles, acylation of fatty acid anhydrides, and amide carbonylation reactions. A preferred method is preparation via the amino reaction of fatty acyl chlorides with amino acids (Shotten-Baumann condensation reaction or Shotten-Baumann reaction).

[0027] A typical preparation process suitable for this invention is as follows: amino acids and sodium hydroxide are dissolved in water or a mixture of water and acetone to obtain an amino acid salt solution; then lauroyl chloride and sodium hydroxide solution are slowly added dropwise to the amino acid salt solution, controlling the pH of the reaction system; after the addition is complete, post-processing of the product is performed. Representative methods are disclosed in CN1798821A, US6703517B2, CN102875409B, JPH0570418A, etc.

[0028] For the post-processing of N-long-chain acyl amino acid products, conventional methods such as recrystallization, water washing, and drying can be used. A preferred post-processing step includes the following steps: mixing the crude N-long-chain acyl amino acid with a solvent, optionally stirring, and controlling the temperature T of the mixed system to be above the melting point of the long-chain fatty acid and below the melting point of the N-long-chain acyl amino acid. The solvent is water, an organic solvent, or a mixture of water and an organic solvent. After temperature control, solid-liquid separation is performed. Related methods are disclosed by the inventors in CN202210867760.7 and PCT / CN2022 / 107270, the contents of which are incorporated herein by reference.

[0029] Increasing the amount of N-long-chain acyl amino acid salts and free N-long-chain acyl amino acids can improve the viscosity of the composition. Formulators can choose the appropriate amount based on the viscosity requirements of the actual product; alternatively, if the viscosity is too high, it can be reduced by diluting with water.

[0030] The inventors have provided a formulation system for synergistic thickening in the presence of free N-long-chain acyl amino acids, combined with hydrophilic nonionic surfactants and amphoteric surfactants. Considering that amphoteric surfactants such as cocamidopropyl betaine have a natural source index of only 0.535, it is preferable that the green thickening composition is substantially free of amphoteric surfactants, more preferably completely free of amphoteric surfactants. The term "substantially free" in this invention means that the content of this substance in the composition will not significantly or substantially affect the performance of the product. Further, "substantially free" means that the weight percentage of this substance in the composition is less than 0.5 wt%, preferably less than 0.1 wt% or less than 0.01 wt%, more preferably less than the detectable limit.

[0031] This invention further uses alkyl glycosides, which have a higher natural source index, to replace betaine. Because this invention eliminates the relatively low natural source index of the amphoteric surfactant betaine, it is particularly preferable to increase the amount of components (a), (a'), and (a'') from a thickening effect perspective. Furthermore, the weight percentage of (a), (a'), or (a'') in the green thickening composition is 15 wt% or more, preferably 20 wt% or more; and 40 wt% or less, preferably 30 wt% or less. For example, it can be 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, 31 wt%, 32 wt%, 33 wt%, 34 wt%, or 35 wt%.

[0032] The appropriate amount of N-long-chain acyl amino acids and / or salts allows the formulation to balance cleaning power and washing feel, as well as thickening with niacinamide. Particularly preferred is that the N-long-chain acyl amino acids and / or salts are the main surfactants in the formulation; a main surfactant is defined as the surfactant present in the highest weight percentage among all surfactants. Preferably, the main surfactant accounts for more than 50 wt% of all surfactants; for example, more than 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, or 80 wt%.

[0033] Furthermore, the weight percentage of free N-long-chain acyl amino acids in the green thickening composition is 2-8 wt%, preferably 3-6 wt%. For example, it can be 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, or 8 wt%. An appropriate amount of free N-long-chain acyl amino acids can balance the viscosity, washability, and low-temperature stability of the formulation.

[0034] Furthermore, for (a') and (a''), the degree of neutralization is controlled to be above 70%, preferably above 75%; and below 90%, preferably below 85%. For example, the degrees of neutralization are 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, and 90%. If the neutralization is too low, the low-temperature stability is poor, and the formulation is prone to precipitation. If the neutralization is too high, there is insufficient free N-long-chain acyl amino acids, the thickening effect is limited, and the formulation becomes watery after the addition of nicotinamide. The aforementioned degree of neutralization refers to the percentage of N-long-chain acyl amino acids that are neutralized. For example, 80% neutralization means that 80% of all N-long-chain acyl amino acids are neutralized by alkali to form salts, leaving 20% ​​as free N-long-chain acyl amino acids.

[0035] For component (c), hydrophilic nonionic surfactants, it refers to a class of nonionic surfactants that are hydrophilic and can be dispersed or dissolved in water to form emulsions or translucent to transparent solutions.

[0036] The present invention primarily prefers O / W type emulsifiers, or solubilizing nonionic surfactants, or nonionic surfactants with HLB 6 or higher.

[0037] The O / W type emulsifier refers to a type of substance that enables the oil phase (O, abbreviated as O) to be uniformly dispersed in the aqueous phase (Water, abbreviated as W) in the form of tiny droplets, forming an oil-in-water (O / W) emulsion. In this invention, the O / W type emulsifier can stabilize free N-long-chain acyl amino acids, ensuring they do not precipitate, and can also have a synergistic effect on thickening.

[0038] The solubilizing nonionic surfactant refers to a nonionic surfactant with solubilizing properties, which can dissolve lipophilic raw materials in water. In this invention, it specifically refers to a surfactant that can dissolve lipophilic free N-long-chain acyl amino acids in water, ensuring that they do not precipitate, and can also have a synergistic effect on thickening.

[0039] Preferably, the natural source index of the hydrophilic nonionic surfactant in (c) is greater than 0.5 and less than or equal to 1, and more preferably greater than 0.8, for example, 0.8, 0.85, 0.9, 0.95, or 1. Further, (c) the hydrophilic nonionic surfactant contains polyglycerol units; the polyglycerol unit refers to a polyglycerol group obtained by glycerol polymerization.

[0040] Furthermore, (c) the hydrophilic nonionic surfactant comprises one or more of polyglycerol-3-methylglucose fatty acid ester, polyglycerol-2-fatty acid ester, polyglycerol-4-fatty acid ester, polyglycerol-6-fatty acid ester, polyglycerol-8-fatty acid ester, polyglycerol-10-fatty acid ester, and polyglycerol-12-fatty acid ester. Taking polyglycerol-10 fatty acid ester as an example, it comprises polyglycerol-10 monostearate, polyglycerol-10 monoisostearate, polyglycerol-10 distearate, polyglycerol-10 oleate, polyglycerol-10 laurate, and polyglycerol-10 decanoate, etc.

[0041] The amount of (c) hydrophilic nonionic surfactant is related to the amount of free N-long-chain acyl amino acids and alkyl glycosides. If the amount of free N-long-chain acyl amino acids or alkyl glycosides is high, the amount of (c) hydrophilic nonionic surfactant can be appropriately reduced. Conversely, if the amount of free N-long-chain acyl amino acids or alkyl glycosides is low, the amount of (c) hydrophilic nonionic surfactant can be appropriately increased. Generally, considering the viscosity-reducing effect of nicotinamide, the weight percentage (on a 100% basis) of (c) hydrophilic nonionic surfactant in the composition is 0.5-15 wt%, preferably 1-10 wt%. For example, it can be 0.5 wt%, 0.7 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, or 10 wt%. (c) Excessive use of hydrophilic nonionic surfactants, although beneficial for thickening, can affect the washing feel / touch of the product to some extent.

[0042] For component (d) alkyl glycoside, it refers to alkyl glycoside surfactants. Classified by "fatty alcohol carbon chain length," there are short carbon chains (C8-C10), medium carbon chains (C12-C14), long carbon chains (C16-C18), and combinations of different carbon chains. It is further selected from one or more of octyl glucoside, decyl glucoside, cocoyl glucoside, lauryl glucoside, stearyl glucoside, palmityl glucoside, APG0810, APG0814, APG1214, APG1618, APG1216, APG0816, and APG2022.

[0043] The amount of (d)alkyl glycoside used is related to the amount of free N-long-chain acyl amino acids and hydrophilic nonionic surfactants. If the amount of free N-long-chain acyl amino acids or hydrophilic nonionic surfactants is high, the amount of (d)alkyl glycoside can be appropriately reduced. Conversely, if the amount of free N-long-chain acyl amino acids or hydrophilic nonionic surfactants is low, the amount of (d)amphoteric surfactant can be appropriately increased. Generally, the weight percentage (on a 100% basis) of (d)alkyl glycoside in the green thickening composition is 1-20 wt%, preferably 2-15 wt%, and particularly preferably 5 wt% or more from a thickening perspective. For example, it can be 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, or 20 wt%.

[0044] The green thickening composition may further contain other ingredients such as preservatives, fragrances / flavors, conditioning agents, dyes, chelating agents, extracts, amino acids, nucleic acids, vitamins, enzymes, anti-inflammatory agents, bactericides, antioxidants, UV absorbers, antiperspirants, pH adjusters, pearlescent agents, etc.

[0045] Based on ISO 16128 or T / SHRH 041-2022 standards, the natural source index of each component (a), (a'), (a''), (b), (c), and (d) of the aforementioned green thickening composition is preferably 0.8 or higher, more preferably 0.9 or higher, and more preferably 1. For example, the natural source index of each component is 0.8, 0.85, 0.9, 0.95, and 1.

[0046] Based on ISO 16128 or T / SHRH 041-2022 standards, the present invention further preferably includes a natural source content of 85% or more, more preferably 90% or more, and even more preferably 95% or more. For example, the natural source content can be 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%.

[0047] The thickening composition of the present invention can be used to prepare personal care products. These personal care products include shower gels, shampoos, facial cleansers, makeup removers, or hand sanitizers, etc.

[0048] In each implementation, details such as the selection of types and dosages not discussed can be referred to the relevant guidance of other implementations if there is no conflict in the content. For the sake of brevity, each implementation has not been described in detail.

[0049] Unless otherwise specified, "above," "below," and "A~B" in this invention all include the stated number. Since the solid content of raw materials varies among different manufacturers, the weight percentage (wt%) of each raw material mentioned in this invention refers to the weight percentage of that component after conversion to 100%. For example, if 10wt% sodium cocoaminopropionate (30% solid content) is added, the actual weight percentage of sodium cocoaminopropionate after conversion to 100% is 3wt%.

[0050] Compared with the prior art, the present invention has the following beneficial technical effects:

[0051] 1. This invention is the first to construct a thickening system containing (a) a salt of N-long-chain acyl amino acids, (b) free N-long-chain acyl amino acids, (c) a hydrophilic nonionic surfactant, and (d) an alkyl glycoside for thickening nicotinamide.

[0052] 2. The natural source index of each component used for nicotinamide thickening can be controlled above 0.8, or even reach 1.

[0053] 3. The natural source content of the green thickening composition of the present invention can exceed 85%.

[0054] The present invention will be further illustrated below with reference to embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalents also fall within the scope defined by the appended claims.

[0055] Example Test Material Description LA stands for lauroyl alanine (from Suzhou Weimei), Arg stands for arginine (from Suzhou Weimei), CMMEA stands for cocamidomethyl MEA, 430 stands for sorbitol polyether-30 tetraoleate (purchased from Kao), 150 stands for PEG-150 pentaerythritol tetrastearate (purchased from Heda), 160 stands for PEG-160 dehydrated sorbitol triisostearate (purchased from Kao), DOE120 stands for PEG-120 methyl glucodioleate (purchased from Lubrizol), and CAB stands for cocamidopropyl betaine.

[0056] The 30% marked in the raw materials (e.g., sodium cocoaminopropionate (30%)) means that the added raw materials are solutions with a solid content of 30%. For example, if 100g of sodium cocoaminopropionate (30%) is added, the actual amount of sodium cocoaminopropionate added is 30g.

[0057] 2. Test instruments Viscometer: Lichen rotational viscometer, model LC-NDJ-55.

[0058] 3. Experimental Procedure Unless otherwise specified, weigh each component according to the formula, heat to 70-85℃, and keep stirring until homogeneous. After the prepared sample has stabilized, remove it, select a suitable rotor and speed, and test the sample viscosity with a viscometer. Low-temperature testing involves keeping it at -5℃ for 48 hours for observation.

[0059] Table 1.1 Effect of free N-long-chain acyl amino acids (sodium cocoylaminopropionate) Formula number 1-1 1-2 1-3 1-4 Element Amount added / g Amount added / g Amount added / g Amount added / g Sodium cocoylaminopropionate (30%) 100 100 100 100 LA 0 0 5.56 5.56 160 5 0 5 0 150 0 5 0 5 Lauryl hydroxysulfonate betaine (30%) 35 35 35 35 glycerin 25 25 25 25 water 85 85 85 85 Viscosity / mPa·s Test Temperature No viscosity at 25℃ 43425℃ 961725℃ 3117025℃ The results showed that for formulations containing sodium cocoylaminopropionate, the solution had almost no viscosity if free N-long-chain acyl amino acids were lacking; however, after adding lauroyl alanine, the viscosity increased by several tens of times, and the solution became transparent and had good low-temperature stability.

[0060] Table 1.2 Effect of free N-long chain acyl amino acids (lauroyl glycine, LA) Formula number 1-5 1-6 1-7 1-8 Element Amount added / g Amount added / g Amount added / g Amount added / g Lauroyl glycine 30 30 0 0 LA 0 0 30 30 Arg 16.3 (80% neutralized) 20.3 (100% neutralized) 15.4 (80% neutralized) 19.3 (100% neutralized) 160 5 5 5 5 Lauryl hydroxysulfonate betaine (30%) 35 35 35 35 glycerin 25 25 25 25 water 138.7 134.7 139.6 135.7 Viscosity / mPa·s Test Temperature 1079925℃ 49.825℃ 5645625℃ 22125℃ Appearance Opaque at room temperature; precipitation occurs at both room temperature and low temperature. Room temperature transparent water Transparent at room temperature; stable at low temperatures with no precipitation. Room temperature transparent water The results showed that, whether it was lauroylglycine or lauroylalanine, if it was completely neutralized with alkali, there were no free N-long-chain acyl amino acids, and the formulation solution had almost no viscosity; if it was partially neutralized with alkali (80% neutralization), about 20% of the N-long-chain acyl amino acids in the formulation were in a free state, and the solution viscosity increased significantly.

[0061] Table 1.3 Effect of free N-long-chain acyl amino acids (lauroyl sarcosine) Formula number 1-9 1-10 1-11 1-12 Element Amount added / g Amount added / g Amount added / g Amount added / g Lauroyl sarcosine 30 30 30 30 NaOH 4.4 (100% neutralized) 3.5 (80% neutralized) 3.5 (80% neutralized) 3.5 (80% neutralized) 150 5 5 0 0 160 0 0 5 0 430 0 0 0 5 Lauryl hydroxysulfonate betaine (30%) 35 35 35 35 glycerin 25 25 25 25 water 150.6 151.5 151.5 151.5 Viscosity / mPa·s Test Temperature No viscosity at 25℃ 784525℃ 715927℃ 18127℃ Appearance Room temperature transparent Transparent at room temperature; micro-precipitation at low temperature, recovers at room temperature. Transparent at room temperature; micro-precipitation at low temperature, recovers at room temperature. Room temperature transparent The results showed that for formulations containing lauroyl sarcosine, if the free N-long-chain acyl amino acid is lacking (100% neutralization with alkali), the solution has no viscosity; however, if the solution is partially neutralized with alkali (80% neutralization), the viscosity of the solution increases, especially when the hydrophilic nonionic surfactant is 150 or 160, the viscosity increase is significant.

[0062] Table 1.4 Effect of free N-long-chain acyl amino acids (LA) Formula number 1-13 1-14 1-15 1-16 Element Amount added / g Amount added / g Amount added / g Amount added / g LA 30 30 30 30 NaOH 3.5 (80% neutralized) 3.5 (80% neutralized) 3.5 (80% neutralized) 3.5 (80% neutralized) 150 5 0 0 0 160 0 5 0 0 430 0 0 5 0 Polyglycerol-10 oleate / polyglycerol-2 oleate 0 0 0 5 Lauryl hydroxysulfonate betaine (30%) 35 35 35 35 glycerin 25 25 25 25 water 151.5 151.5 151.5 151.5 Viscosity / mPa·s Test Temperature 7053725℃ 3400725℃ 241425℃ 908625℃ Appearance Transparent at room temperature; micro-precipitation at low temperature, recovers at room temperature. Transparent at room temperature; micro-precipitation at low temperature, recovers at room temperature. Transparent at room temperature; precipitates at low temperature and recovers at room temperature. Transparent at room temperature; precipitates at low temperature and recovers at room temperature. Formula number 1-17 1-18(1-7) 1-19 1-20 Element Amount added / g Amount added / g Amount added / g Amount added / g LA 30 30 30 30 Arg 15.4 (80% neutralized) 15.4 (80% neutralized) 15.4 (80% neutralized) 15.4 (80% neutralized) 150 5 0 0 0 160 0 5 0 0 430 0 0 5 0 Polyglycerol-10 oleate / polyglycerol-2 oleate 0 0 0 5 Lauryl hydroxysulfonate betaine (30%) 35 35 35 35 glycerin 25 25 25 25 water 139.6 139.6 139.6 139.6 Viscosity / mPa·s Test Temperature >100,000 25℃ 5645625℃ 116925℃ 270125℃ Appearance Transparent at room temperature; stable at low temperatures, near-solid gel, with no precipitation. Transparent at room temperature; stable at low temperatures, near-solid gel, with no precipitation. Transparent at room temperature; stable at low temperatures with no precipitation. Transparent at room temperature; stable at low temperatures with no precipitation. The results showed that, compared to lauroyl sarcosine (1-9 to 1-12), the thickening effect of the formulation containing lauroyl alanine (1-13 to 1-20) was improved by more than 5-10 times. Partial neutralization of lauroyl alanine with a basic amino acid (arginine) resulted in significantly better low-temperature stability than partial neutralization with an inorganic base (sodium hydroxide).

[0063] Table 2 Thickening effect of alkyl glycosides replacing betaine on nicotinamide (wt% is the content after 100% conversion) Formula number 2-1 (Comparison) 2-2 (Comparison) 2-3 (Comparison) 2-4 (This invention) 2-5 (This invention) Element Amount added / wt% Amount added / wt% Amount added / wt% Amount added / wt% Amount added / wt% LA 8 6 8 17.4 18.4 NaOH 0.99 (85% neutralized) 0 1.00 (85% neutralized) 0 0 Arg 0 3.08 (80% neutralized) 0 9.00 (80% neutralized) 9.45 (80% neutralized) 150 0.7 0.4 0.8 0 0 Polyglycerol-2-laurate 4 3 4 0 3 Polyglycerol-10 stearate 0 0 0 5 0 CAB 3 3 3 0 0 Sodium cocoyl hydroxyethyl sulfonate 2.5 0 0 0 0 Alkyl glycosides 4-decyl glucoside 3[APG12] 4[APG12] 9-decyl glucoside 9-decyl glucoside Niacinamide 2 2 2 2 2 water margin margin margin margin margin Viscosity / mPa·s Test Temperature 158920℃ 410620℃ 790520℃ 605820℃ 1871020℃ The results showed that even without the addition of betaine CAB, the thickening system of (a') lauroyl alanine partially neutralized with arginine, (c) a hydrophilic nonionic surfactant, and (d) alkyl glycosides effectively thickened (e) nicotinamide. The natural source index of the raw materials LA, Arg, polyglycerol-2-laurate, polyglycerol-10-stearate, and alkyl glycosides used in formulations 2-4 and 2-5 of this invention is all 1, and the total natural source content of the entire formulation exceeds 95%.

[0064] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features included in other embodiments but not others, combinations of features from different embodiments are meant to be within the scope of the invention and form different embodiments.

Claims

1. A green thickening composition containing nicotinamide, characterized in that, The composition comprises (a) a salt of an N-long-chain acyl amino acid, (b) a free N-long-chain acyl amino acid, (c) a hydrophilic nonionic surfactant, (d) an alkyl glycoside, and (e) nicotinamide; Alternatively, the composition comprises (a') an N-long-chain acyl amino acid neutralized with an alkali portion to a degree of neutralization of less than 100%, such that it contains a salt of the N-long-chain acyl amino acid and unneutralized free N-long-chain acyl amino acid, (c) a hydrophilic nonionic surfactant, (d) an alkyl glycoside, and (e) nicotinamide. Alternatively, the composition comprises (a'') a base and an N-long-chain acyl amino acid, wherein the molar number of the base is less than that of the N-long-chain acyl amino acid, such that the neutralization degree of the N-long-chain acyl amino acid is less than 100%, thereby containing a salt of the N-long-chain acyl amino acid and free N-long-chain acyl amino acid, (c) a hydrophilic nonionic surfactant, (d) an alkyl glycoside, and (e) nicotinamide.

2. The green thickening composition containing nicotinamide according to claim 1, characterized in that, The N-long-chain acyl amino acid mentioned in (a), (a'), (a''), and (b) is lauroyl alanine, and the base is a basic amino acid, preferably arginine.

3. The green thickening composition containing nicotinamide according to claim 1, characterized in that, The weight percentage of component (a), (a') or (a'') in the composition is 15 wt% or more, preferably 20 wt% or more; And / or, the free N-long-chain acyl amino acids in the composition have a weight percentage of 2 wt% or more, preferably 3 wt% or more; And / or, for (a') and (a''), the degree of neutralization is 70% or more, preferably 75% or more; and the degree of neutralization is 90% or less, preferably 85% or less.

4. The green thickening composition containing nicotinamide according to claim 1, characterized in that, (c) The hydrophilic nonionic surfactant is an O / W type emulsifier; or a solubilizing nonionic surfactant; or a nonionic surfactant with HLB of 6 or more, preferably 8 or more, and more preferably 10 or more.

5. The green thickening composition containing nicotinamide according to claim 1, characterized in that, (c) The hydrophilic groups of hydrophilic nonionic surfactants contain polyglycerol units.

6. The green thickening composition containing nicotinamide according to claim 1, characterized in that, (c) The hydrophilic nonionic surfactant includes one or more of polyglycerol-3-methylglucose fatty acid ester, polyglycerol-2-fatty acid ester, polyglycerol-4-fatty acid ester, polyglycerol-6-fatty acid ester, polyglycerol-8-fatty acid ester, polyglycerol-10-fatty acid ester, and polyglycerol-12-fatty acid ester.

7. The green thickening composition containing nicotinamide according to claim 1, characterized in that, Based on ISO 16128 or T / SHRH 041-2022 standards, the natural source index of each component (a), (a'), (a''), (b), (c), and (d) is above 0.8, preferably above 0.9, and more preferably 1; And / or, based on ISO 16128 or T / SHRH 041-2022 standards, the natural source content of the green thickening composition is 85% or more, preferably 90% or more, and more preferably 95% or more.

8. The green thickening composition containing nicotinamide according to claim 1, characterized in that, The green thickening composition contains virtually no amphoteric surfactants, and preferably none at all.

9. The green thickening composition containing nicotinamide according to claim 1, characterized in that, The weight percentage of component (a), (a'), or (a'') in the green thickening composition is 15-40 wt%, preferably 20-30 wt%; And / or, (b) the free N-long-chain acyl amino acids in the green thickening composition are present in a weight percentage of 2-8 wt%, preferably 3-6 wt%; And / or, (c) the hydrophilic nonionic surfactant is present in the green thickening composition at a weight percentage of 0.5-15 wt%, preferably 1-10 wt%; And / or, the (d) alkyl glycoside is present in the green thickening composition at a weight percentage of 1-20 wt%, preferably 2-15 wt%; And / or, (e) nicotinamide is present in the green thickening composition at a weight percentage of 0.1-10 wt%, preferably 0.5-5 wt%.

10. The use of a green thickening composition containing nicotinamide as described in any one of claims 1-9 in the preparation of personal care products; more preferably, the personal care products are shower gels, shampoos, facial cleansers, makeup removers, or hand sanitizers.