Gemini surfactant, preparation method therefor and use thereof

Abstract

The present invention belongs to the field of surfactants and uses thereof, and specifically relates to a gemini surfactant, a preparation method therefor, and a use thereof. The surfactant is prepared by means of reacting a fatty acyl halide with L-cysteine in a mixed system of water and an organic solvent, resulting in a gemini surfactant containing multiple amide groups and carboxyl groups. The gemini surfactant of the present invention has relatively high surface activity and relatively low critical micelle concentration. It is used in the preparation of washing and care, skincare, and fabric care products, and can exhibit excellent emulsification stability, dispersion stability and rapid penetration for hair, skin and fabrics. Its unique gemini cysteine structure can participate in the structural repair of hair, skin and fabrics on surfaces and in interiors thereof, with low irritation. It has excellent efficacy for repairing skin, hair and fabric, especially for hair damaged by perming or dyeing, including the cuticle, scales, cortex and medulla.

Description

Gemini surfactant and its preparation method and application TECHNICAL FIELD

[0001] The present application belongs to the field of surfactants and its application, and particularly relates to a Gemini surfactant and its preparation method and application. BACKGROUND

[0002] Surfactants are the most important materials in personal care products and household care products. With the improvement of living standards, people's awareness of health and environmental protection is constantly enhanced, so more and more consumers and businesses will pay attention to environmentally friendly surfactants, especially amino acid surfactants.

[0003] Amino acid derivatives containing amide groups can form micelles even in trace amounts in cosmetics, reduce surface tension, and have excellent performance in emulsifying power, dispersing power, and moisture absorption and retention. Fatty acyl cystine is prepared from two natural source materials, amino acid and fatty acid, and has multiple biocompatible groups such as amide groups and carboxyl groups. It has the advantages of low irritation and mitigation of irritation of other active ingredients when used in personal care products and household care products. SUMMARY

[0004] The present application aims to overcome the problems in the prior art and provides a Gemini surfactant and its preparation method and application. The Gemini surfactant of the present application has high surface activity and low critical micelle concentration, and can be used in the preparation of washing and care products, skin care products, and fabric washing and care products, and can exhibit excellent emulsifying stability, dispersing stability, and rapid permeability on hair, skin, and fabric. The unique Gemini cystine structure of the present application can participate in the structural repair of hair, skin, and fabric on the surface and inside of hair, skin, and fabric, and has low irritation, and good repair effect on skin, hair, and fabric tissue, especially on permed and dyed damaged hair including hair cuticle, hair scale, hair shaft, and hair medulla.

[0005] The object and solution to the technical problem of the present application are achieved by using the following technical scheme.

[0006] The first aspect of the present application provides a Gemini surfactant, which is prepared by reacting fatty acyl halide with L-cystine in a water and organic solvent mixed system to obtain a Gemini surfactant containing multiple amide groups and carboxyl groups.

[0007] [According to Rule 26, corrected on 08.05.2025] In some preferred embodiments of the present application, the surfactant has the following general structure: Formula I;

[0008] [According to Rule 26, corrected on 08.05.2025]

[0009] Formula I

[0010] In Formula I, X is a hydrogen atom, an alkali metal, an alkaline earth metal, an amine, or a basic amino acid; C n H 2n+1 is a C7~C 21 saturated or unsaturated hydrocarbon group, which can or can not contain a branch.

[0011] In some preferred embodiments of the present application, the C7~C 21 The saturated or unsaturated hydrocarbon group is a single carbon chain or a mixed carbon chain, including but not limited to lauryl, myristyl, or cocoyl.

[0012] In some preferred embodiments of the present application, the alkali metal includes but is not limited to sodium, potassium; the alkaline earth metal includes but is not limited to calcium, magnesium; the amine includes but is not limited to triethanolamine, triethylamine; and the basic amino acid includes but is not limited to arginine.

[0013] A second aspect of the present application provides a method for preparing the aforementioned Gemini surfactant, comprising the following steps:

[0014] 1) Dissolve L-cystine in a water / isopropanol mixture, adjust the pH to 10 with a lye, and make it clear;

[0015] 2) Add lauroyl halide dropwise to the reaction system while adding lye as an acid-binding agent, and control the temperature to 10-30°C during the process;

[0016] 3) Continue to add lye until the amount of lye added reaches 4.0 eq;

[0017] 4) After the reaction is completed, filter the reaction liquid to obtain lauroyl cystine or its salt crude product, and recrystallize the crude product using ethanol / water.

[0018] In some preferred embodiments of the present application, the water / isopropanol mixture, in which isopropanol is 0-100% v / v, preferably 0-30% v / v.

[0019] In some preferred embodiments of the present application, the lye is one of a potassium hydroxide, a sodium hydroxide, a calcium hydroxide, and a magnesium hydroxide aqueous solution, preferably a sodium hydroxide or a potassium hydroxide aqueous solution.

[0020] In some preferred embodiments of the present application, the lauroyl halide is preferably lauroyl chloride, and the reaction temperature is preferably 25-30°C.

[0021] In some preferred embodiments of the present application, the ethanol / water crude product crystallization system, in which ethanol is 50-95% v / v, preferably 90-95% v / v.

[0022] The third aspect of the present application provides a product for personal care and home care, comprising the aforementioned Gemini surfactant, or the Gemini surfactant prepared according to the aforementioned preparation method.

[0023] In some preferred embodiments of the present application, the amount of the Gemini surfactant in the product is not less than 0.004 wt%, preferably 0.004-50.0 wt%, more preferably 0.01%-20%, and further preferably 0.02%-6.0%, based on the total mass of the product.

[0024] In some preferred embodiments of the present application, the product comprises personal care products, personal skin care products, home cleaning products, and home care products.

[0025] In some preferred embodiments of the present application, the personal care products include, but are not limited to, one or more of shampoos, hair conditioners, body washes, hand washes, hand soaps, exfoliating scrubs, facial cleansers, emulsified skin care products, oil-based skin care products, water-based spray skin care products, paste and gel skin care products, toothpaste, mouthwash, laundry detergents, fabric softeners, and dishwashing detergents.

[0026] In some preferred embodiments of the present application, the product comprises, in addition to the Gemini surfactant, other commonly used ingredients for preparing personal care or skin care and home cleaning and care products; the other commonly used ingredients include, but are not limited to, one or more of anionic surfactants, cationic conditioning agents, nonionic surfactants, zwitterionic surfactants, emulsifiers, skin care oils, other conditioning agents, softeners, functional additive ingredients, and other functional additives required in the product.

[0027] In some preferred embodiments of the present application, the anionic surfactant includes a high fatty acid salt (soap) having 8 to 20 carbon atoms in the hydrophobic group portion, an n-acyl amino acid type anionic surfactant having 8 to 20 carbon atoms in the acyl group, and an amino acid as a component; the amino acid includes an acidic amino acid such as glutamic acid, aspartic acid, glycine, alanine, valine, leucine, isoleucine, proline, methionine, cystine, tryptophan, tyrosine, phenylalanine, asparagine, glutamine, serine, threonine, proline, β-aminopropionic acid, γ-aminobutyric acid, o-aminobenzoic acid, m-aminobenzoic acid, p-aminobenzoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, elaidic acid, undecylenic acid, lanolin fatty acid, hard lanolin fatty acid, soft lanolin fatty acid, linoleic acid, linolenic acid, eicosapentaenoic acid, 12-hydroxystearic acid, alkyl ether carboxylate, amido ether carboxylate, alkyl sulfate ester salt (AS), polyoxyethylene alkyl ether sulfate ester salt (AES), alkyl ether sulfate, high fatty acid alkyl amide sulfate, sulfated oil, polyoxyethylene phenyl ether sulfate, alpha-olefin sulfonate (AOS), alkyl benzene sulfonate, alkyl naphthalene sulfonate, alkyl sulfonate (SAS), dialkyl sulfosuccinate, alpha-sulfonated fatty acid salt, alkane sulfonate, high fatty acid ester sulfonate, sulfonated fatty acid salt, high fatty acid amide sulfonate, n-acyl-n-alkyl taurate, n-acyl-n-methyl taurate, alkyl phosphoric acid, alkyl ether phosphoric acid, polyoxyethylene alkyl ether phosphoric acid, polyoxyethylene alkyl phenyl ether phosphoric acid, and naphthalene sulfonic acid formalin coagulum.

[0028] In some preferred embodiments of the present application, the cationic conditioning agent includes a primary to tertiary fatty acid amine salt, alkyl ammonium chloride, tetraalkyl ammonium salt, trialkyl benzyl ammonium salt, alkyl pyridine diammonium salt, alkyl hydroxyethyl imidazole salt, dialkyl morpholine salt, alkyl isoquinoline salt, benzyl ammonium salt, and benzalkonium chloride salt.

[0029] In some preferred embodiments of the present application, the nonionic surfactant includes a polyoxyethylene alkyl ether (AE) and the like ethylene oxide condensate, polyoxyethylene alkyl phenyl ether, polyoxyethylene polyphenyl phenyl ether, polyoxyethylene polyoxypropylene polyethylene glycol, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene polyoxypropylene sorbitol fatty acid ester, polyoxyethylene fatty acid alkanolamide, polyoxyethylene alkyl glycoside, polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl amine, polyoxyethylene alkyl phenyl ether, polyhydroxy alcohol fatty acid partial ester such as polyhydroxy alcohol fatty acid partial ester, polyoxyethylene polyhydroxy alcohol fatty acid partial ester, polyoxyethylene fatty acid ester, (poly)glycerin fatty acid ester, polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl amine, triethanolamine fatty acid partial ester, alkyl polyglycoside, propylene glycol fatty acid ester, sorbitol fatty acid ester, and sucrose fatty acid ester, fatty acid alkanolamide, sugar amido compound, triethanolamine fatty acid partial ester, fatty acid alkyl amide, and alkyl amine oxide.

[0030] In some preferred embodiments of the present application, the amphoteric surfactants include alkylbetaines, alkylamidobetaines, alkylsulfoxide betaines, imidazoline betaines, betaines of acetic acid, and lecithin.

[0031] In some preferred embodiments of the present application, the other common ingredients further include, but are not limited to, one or several mixtures of polymeric surfactants, natural surfactants, fats and oils, higher alcohols, sterols, polyols, esters, silicones.

[0032] In some preferred embodiments of the application, the polymeric surfactants include sodium alginate, starch derivatives, and tragacanth; the natural surfactants include phospholipids, lecithin, lanolin, cholesterol, and saponins; the fats and oils include avocado oil, turtle oil, corn oil, almond oil, olive oil, cocoa butter, sesame oil, safflower oil, soybean oil, tea oil, anise oil, castor oil, grape seed oil, kukui nut oil, mink oil, cottonseed oil, Japanese wax, coconut oil, egg yolk oil, palm oil, palm kernel oil, glyceryl triisooctanate, glyceryl tri-2-ethylhexanoate, cholesterol fatty acid ester, wheat germ oil, jojoba oil, flaxseed oil, evening primrose oil, perilla oil, peanut oil, tea seed oil, Japanese nutmeg oil, rice bran oil, Chinese tung oil, Japanese tung oil, germ oil, glyceryl trioctanoate, glyceryl triisopalmitate, horse oil, hydrogenated coconut oil, beef tallow, beef foot oil, mutton fat, hardened beef tallow, lard, beef bone oil, Japanese wax kernel oil, hydrogenated oil, Japanese wax, hydrogenated castor oil, liquid paraffin, vaseline, paraffin wax, microcrystalline wax, isoparaffin wax, zeolite, squalene, pristane, squalane, beeswax, whale oil, lanolin, carnauba wax, candelilla wax, cotton wax, bayberry wax, insect wax, montan wax, bran wax, lanolin, kapok wax, lanolin acetate, liquid lanolin, sugar cane wax, isopropyl lanolate, hexyl laurate, reduced lanolin, jojoba wax, hard lanolin, shellac wax, polyoxyethylene lanolin alcohol ether, polyoxyethylene lanolin alcohol acetate, polyethylene glycol lanolate, polyoxyethylene hydrogenated lanolin alcohol ether, and derivatives thereof; the higher alcohols include dodecanol, cetyl alcohol, cetearyl alcohol, stearyl alcohol, oleyl alcohol, dephenolized alcohol, lanolin alcohol, hydrogenated lanolin alcohol, hexyldecanol, and octyldodecanol; the sterols include cholesterol and phytosterols; the polyols include glycerol, diglycerol, polyglycerol, 1,3-butanediol, propylene glycol, and polyethylene glycol;The esters include isopropyl myristate, butyl stearate, cetyl octanoate, octyldodecyl myristate, isopropyl palmitate, hexyl laurate, decyl myristate, decyl oleate, dimethyl hexyl decanoate, cetyl lactate, myristyl lactate, lanolin acetate, isooctyl stearate, isooctyl isostearate, 12-hydroxystearate, ethylene glycol di-2-ethylhexanoate, dipentaerythritol fatty acid ester, n-alkyl glycol mono isostearate, neopentyl glycol dihexanoate, diisocetyl malate, glycerol di-2-heptylundecanoate, trimethylolpropane triisostearate, pentaerythritol tetra-2-ethylhexanoate, glycerol tri-2-ethylhexanoate, trimethylolpropane triisostearate, decanoic acid-2-ethylhexanoate, palmitic acid 2-ethylhexanoate, glycerol triacetate, glycerol tri-2-heptylundecanoate, methyl castor oil fatty acid ester, oleic acid oil, decyl stearate, acetyl glycerin, 2-octyl palmitate, diisopropyl adipate, n-lauroyl-l-glutamic acid, 2-octyldodecyl ester, di-2-octylhexyl adipate, ethyl laurate, di-2-ethylhexyl sebacate, dihexyl myristate, diisopropyl sebacate, 2-ethylhexyl hexyl succinate, ethyl acetate, butyl acetate, amyl acetate, and triethyl citrate; the silicones include dimethyl polysiloxane, polyether-modified silicone, alcohol-modified silicone, methylphenyl polysiloxane, epoxy-modified silicone, fluorine-modified silicone, alkyl-modified silicone, amino-modified silicone, polymer silicone, and cyclosiloxane.

[0033] In some preferred embodiments of the present application, the other common ingredients further comprise additives, including but not limited to one or several of emulsifiers, conditioning agents, emollients, humectants, moisturizers, lubricants, chelating agents, fillers, antioxidants, preservatives, active ingredients, fragrances, dyes, buffers, exfoliating agents, pH adjusters, inorganic salts, solvents, viscosity adjusters, and opacifiers; the emollients, humectants, moisturizers, lubricants, chelating agents, fillers, antioxidants, preservatives, active ingredients, fragrances, dyes, buffers, exfoliating agents, pH adjusters, inorganic salts, solvents, viscosity adjusters, etc. are all conventional components in the art, and are not limited here.

[0034] In some preferred embodiments of the present application, the product additive can further include: natural rubber such as gum arabic and gum yellow; glycoside such as saponin; cellulose derivatives such as methyl cellulose, carboxy cellulose-cellulose and hydroxymethyl cellulose; natural polymers such as lignin sulfonate and shellac; anionic polymers such as polyacrylate, styrene-acrylic acid copolymer salt, vinyl naphthalene-maleic acid copolymer salt, β-naphthalene sulfonic acid-formalin condensate and sodium salt of phosphate; non-ionic polymers such as polyvinyl alcohol, polyvinyl pyrrolidone and polyethylene glycol; water-soluble and fat-soluble polymers such as hydroxyethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose hydroxypropyl methyl trimethyl ammonium ether, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, methyl hydroxypropyl cellulose, soluble starch, carboxymethyl starch, methyl starch, propylene glycol ester, alginic acid ester, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl ether, carboxy vinyl polymer, polyacrylate, guar gum, tara gum, bee gum, carrageenan gum, galactose, gum arabic, pectin, mannan, starch, xanthan gum, dextran, succinic acid dextran, carrageenan, hyaluronic acid, gelatin, casein, albumin, collagen, methoxy ethylene maleic anhydride copolymer, amphoteric methacrylate ester copolymer, polydimethyl methylene piperidine chloride, polyacrylate ester copolymer, polyvinyl acetate, nitrocellulose and silicone.

[0035] In some preferred embodiments of the present application, the product additive further includes one or several of thickening and foaming ingredients, oil gelling agents, metal ion sequestering agents, dandruff and itch preventing agents, ultraviolet light absorbers, whitening agents, anti-inflammatory agents, astringents, cooling agents, antihistamines, sebum inhibitors, keratin peeling and dissolving agents, cosmetic colorants.

[0036] In some preferred embodiments of the present application, the thickening and foaming ingredients include: cationic polymers such as cationized cellulose derivatives, cationized starch, cationized guar gum derivatives, diallyl quaternary ammonium salt / acrylamide copolymer, quaternized polyvinyl pyrrolidone derivatives, quaternary vinyl / vinyl imidazole polymers, polyamino condensate, polyquaternized collagen polypeptide, polyethylene imine, cationic silicon polymer, adipic acid / dimethyl amino hydroxypropyl diethylene triamine copolymer, polyamino polyamide, cationized chitin derivatives and quaternized polymeric polyethylene glycol fatty acid ester; polyoxyethylene fatty acid ester methyl glycoside and tetradecene sulfonate.

[0037] In some preferred embodiments of the present application, the oil gelling agents include dextrin fatty acid ester, glycerol fatty acid ester and hydroxy stearic acid.

[0038] In some preferred embodiments of the present application, the metal ion sequestering agent includes ethylenediaminetetraacetic acid and its salts, hydroxyethylenediaminetriacetic acid and its salts, phosphoric acid, ascorbic acid, succinic acid, gluconic acid, polyphosphates, metaphosphates, and pruinos.

[0039] In some preferred embodiments of the present application, the dandruff and itch preventing agent includes trichloro-rocalamine, salicylic acid, zinc pyrithione, isopropyl-ethyl phenol, and the like.

[0040] In some preferred embodiments of the present application, the ultraviolet light absorbing agent includes benzophenone derivatives, p-aminobenzoic acid derivatives, p-aminoethoxy cinnamic acid derivatives, salicylic acid derivatives, and the like.

[0041] In some preferred embodiments of the present application, the whitening agent includes ascorbic acid and its salts such as sodium salt, potassium salt, magnesium salt, calcium salt, and alkali metal salts and alkaline earth metal salts such as ammonium salt and amino acid salt; ascorbic acid derivatives such as alkyl L-ascorbic acid ester, L-ascorbic acid phosphate ester and its salts, L-ascorbic acid-2 sulfate ester and its salts, and L-ascorbic acid glucoside; alkoxy salicylic acid and its salts such as methoxy, ethoxy, epoxy, isopropoxy, butanol, and isobutanol; hydroquinone glycoside and its derivatives such as albumin; pyrocatechuic acid and its derivatives, ellagic acid, chamomile extract, garlic extract, licorice extract, mulberry bark extract, raspberry extract, apple flavonoid extract, vitamin E and its derivatives, tenasporenol, placenta extract, leucine, glutathione, clove extract, tea extract, astaxanthin, bovine placenta extract, tranexamic acid and its derivatives, resorcinol and its derivatives, azoalkene, and γ-hydroxybutyric acid.

[0042] In some preferred embodiments of the present application, the anti-inflammatory agent includes glycyrrhizinic acid, glycyrrhizinic acid derivatives, allantoin, aminocaproic acid, and hydrocortisone; the astringent agent includes zinc oxide, zinc sulfate, aluminum chloride, zinc sulfate, tannic acid, citric acid, and lactic acid; the cooling agent includes menthol and camphor; the antihistamine agent includes diphenhydramine hydrochloride, chlorpheniramine maleate, and glycyrrhizinic acid derivatives; and the sebum inhibitor includes estradiol, estrone, and ethinyl estradiol.

[0043] In some preferred embodiments of the present application, the keratin peeling and dissolving agent includes sulfur, salicylic acid, and resorcinol; α-hydroxy acid such as glycolic acid, lactic acid, malic acid, tartaric acid, and citric acid; and β-hydroxy acid such as salicylic acid.

[0044] In some preferred embodiments of the present application, the cosmetic colorant comprises talc, kaolin, sericite, calcium carbonate, zinc oxide, aluminum oxide, magnesium oxide, zirconium oxide, magnesium carbonate, calcium carbonate, barium sulfate, chromium oxide, chromium hydroxide, tar-based colorants, mica, silicon carbide, boron nitride, titanium dioxide, black titanium oxide, iron blue, red iron oxide, black iron oxide, yellow iron oxide, deep blue, titanium-coated mica, bismuth oxychloride, bengal, combined pigments, deep blue powder, deep blue violet, chromium hydroxide, mica titanium, chromium oxide, aluminum oxide cobalt, carbon black, magnesium silicate, bentonite, zirconium oxide, magnesium aluminum silicate, calcium aluminum silicate, polyethylene powder, nylon powder, polymethyl methacrylate, polyethylene terephthalate polymethyl methacrylate layered powder, acrylonitrile-methyl methacrylate copolymer powder, vinylidene chloride-methyl methacrylate copolymer powder, wool powder, silk powder, crystalline cellulose, n-acyl lysine, polymethyl sils- esquioxane powder, plant fruit or peel powder, mica titanium, iron oxide-coated mica, iron oxide mica titanium, organic pigment-treated mica titanium, aluminum powder, micro-particle titanium oxide, micro-particle zinc oxide, micro-particle titanium oxide-coated mica titanium, micro-particle zinc oxide-coated mica titanium, micro-particle zinc oxide-coated mica titanium, micro-particle barium sulfate-coated mica titanium, carmine, beta-carotene, metal soaps, chlorophyll, sunset yellow, tetrabromofluorescein, rhodamine B, quinoline yellow SS, quinoline yellow WS, alizarin cyanine green, quinine green, pamaquin red, phthalocyanine blue, beta-apo-8-carotenoic acid, capsaicin, crocin, canthaxanthin, narcissin, lycine, carmine, camphorin, rutin, quercetin, cocoa colorant, riboflavin, urushic acid, carminic acid, alizarin, alizarin, alkanin, nickel chromium, hemoglobin, curcumin, betaine, pure water, firethorn extract, n-methyl-1-serine, whey, nicotinamide, diisopropyl-propylamine dichloroacetic acid, methylhydroxy acid, y-amino butyric acid (including gamma-amino beta-hydroxy butyric acid), althea extract, aloe vera extract, apricot kernel extract, turmeric extract, oolong tea extract, dried seawater, hydrolyzed wheat flour, hydrolyzed silk, carrot extract, cucumber extract, radix ginseng extract, yeast extract, rice germ extract, radix lithospermi extract, medicinal sophora extract, radix rehmanniae extract, radix gageoxylicae extract, white birch extract, peppermint extract, swertia extract, propolis, luffa extract, platycodon flower extract, hops extract, aesculus hippocastanum extract, melissa leaf extract, eucalyptus leaf extract, ginseng leaf extract, rosemary extract, wild chrysanthemum flower extract, royal jelly extract, seaweed, rice bran, licorice, citrus peel, angelica, peach leaf, sphingolipids, guaiane, and vitamin C.

[0045] The fourth aspect of the present application provides a use of the Gemini surfactant in the preparation of a product for personal washing and care, wherein the Gemini surfactant is the aforementioned Gemini surfactant, or the Gemini surfactant prepared according to the aforementioned preparation method.

[0046] By means of the above technical solution, the present application has at least the following advantages: the Gemini surfactant of the present application has high surface activity and low critical micelle concentration, and can be used in the preparation of personal washing and care products, and can exhibit excellent emulsification stability and dispersion stability, low irritation, good repair and conditioning effects on damaged hair, and good care effects on high-osmotic skin. BRIEF DESCRIPTION OF DRAWINGS

[0047] Fig. 1 is a blank control group of hair cuticle repair test;

[0048] Fig. 2 is an effect diagram of hair cuticle repair test after the hair treated by shampoo added with the solution of Example 1 of the present application;

[0049] Fig. 3 is an effect diagram of hair cuticle repair test after the hair treated by shampoo added with the solution of Comparative Example 1. DETAILED DESCRIPTION

[0050] In order to make the technical means, creative features, purposes and effects achieved by the present application easy to understand, the technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0051] Example 1: Preparation of sodium lauroyl cysteinate solution

[0052] 100 g of L-cysteine (0.416 mol) was dissolved in a 20% v / v isopropanol / water solution (1000 ml), and 30 wt% sodium hydroxide aqueous solution was used to adjust the pH to 10. After stirring to dissolve, the solution was cooled to 20℃, and lauroyl chloride (0.458 mol, 1.1 eq) was added dropwise, while 30 wt% sodium hydroxide aqueous solution was added dropwise. After the dropwise addition was completed, the solution was incubated at 25℃ for 1 h, and then sodium hydroxide solution was continuously added to 4.0 eq. The reaction solution was filtered to obtain crude sodium lauroyl cysteinate. The crude product was recrystallized using a 95% v / v ethanol / water solution (1000 ml), and the obtained white flaky crystals were sodium lauroyl cysteinate, which was prepared into a 20 wt% aqueous solution.

[0053] Example 2: Preparation of potassium octanoyl cysteinate solution

[0054] Dissolve 100 g of L-cystine (0.416 mol) in a 30% v / v isopropyl alcohol / water solution (1000 ml), adjust to pH 10 using a 30 wt% aqueous potassium hydroxide solution, stir to dissolve, then cool to 20°C, and add octanoyl chloride (0.458 mol, 1.1 eq) dropwise while adding a 30 wt% aqueous potassium hydroxide solution dropwise. After the dropwise addition is complete, maintain the reaction at 20°C for 1 h, continue to add the potassium hydroxide solution to 4.0 eq, and filter the reaction solution to obtain crude potassium octanoyl cysteinate. Recrystallize the crude product from a 70% v / v ethanol / water solution (1000 ml) to obtain white plate-like crystals of sodium octanoyl cysteinate.

[0055] Comparative Example 1

[0056] Use commercially available lauryl sulfosuccinate disodium as a raw material to prepare a 20% mass percentage aqueous solution.

[0057] Application Example 1: Emulsification performance and emulsion stability test

[0058] First, weigh the required ingredients according to the mass percentage of the test formula in Table 1, then mix the paraffin oil, cetylstearyl alcohol, and polyacrylic acid in pure water, take 3 portions, and then add the aqueous solutions of Example 1, Example 2, and Comparative Example 1, respectively, and other ingredients. Adjust the pH to 6-8 using a citric acid solution, and emulsify the prepared solution using a homogenizer (6000 r / min) at room temperature for 5 min.

[0059] Table 1: Emulsification performance test formula

[0060] ;

[0061] Observe the emulsion stability of the obtained mixed solution after 1 month, 2 months, and 3 months, respectively, by visual inspection, and the emulsion stability standard is shown in Table 2.

[0062] Table 2: Emulsion stability evaluation standard

[0063] ;

[0064] By visual inspection and referring to Table 2, the test results are as follows:

[0065] Table 3: Stability test results of different products

[0066] ;

[0067] From the evaluation results in Table 3, it can be seen that the emulsification of Examples 1 and 2 is complete and remains unchanged; although the emulsification of Comparative Example 1 is also complete, the emulsification degree decreases with longer standing time. The emulsification performance of the product of the present application is comparable to that of the commercially available product, but the emulsion stability is significantly higher than that of the commercially available product (Comparative Example 1).

[0068] Application Example 2: Dispersion stability test

[0069] Titanium oxide was added to the aqueous solutions of Example 1, Example 2 and Comparative Example 1 at a concentration of 1 wt%, and 10 wt% aqueous citric acid solution was added to adjust the pH to 7-8. After ultrasonic treatment for 30 seconds and homogenization (10000 rpm, 2 minutes), the absorbance of the supernatant was measured when it was left to stand at 50°C (wavelength: 300 nm), and the dispersion performance and dispersion stability of the products of the examples and the comparative example were compared. The initial absorbance of all samples was about 1.8, and the absorbance was measured after 100 hours, 124 hours and 148 hours, respectively, and the results were evaluated as follows, as shown in Table 5.

[0070] Table 4: Evaluation criteria for absorbance

[0071] ;

[0072] Table 5: Results of absorbance detection of different products

[0073] ;

[0074] As can be seen from the test results in Table 5, the dispersion stability of titanium oxide in water of the products of Example 1 and Example 2 is better than that of the product of Comparative Example 1.

[0075] Application Example 3: Foam boosting and stabilizing performance test

[0076] The foam boosting and stabilizing performance of the products of Example 1, Example 2 and Comparative Example 1 was determined as follows: 80 mL of an aqueous solution of the sample at a concentration of 0.001 mol / L was prepared, and 20 mL of the solution was taken into a 100 mL graduated cylinder, which was placed in a 25°C constant temperature water bath for 10 minutes. The solution was shaken vigorously for 20 times, left to stand, and the initial volume of the generated foam (H0), the volume of the foam at 5 minutes (H5) and the time required for the foam volume to decay to half of the initial volume (t1 / 2, half-life) were recorded.

[0077] The foam boosting and stabilizing performance test data of the samples are shown in Table 6:

[0078] Table 6: Results of foam boosting and stabilizing performance test of different surfactants

[0079] ;

[0080] As can be seen from the results in Table 6, the products of Example 2 and Comparative Example 1 have relatively abundant foam, but the foam stability of the products of Example 1 and Example 2 is relatively high, and the foam retention time is relatively long.

[0081] Example 4: Hair cuticle repair test

[0082] A hair cuticle repair shampoo with the surfactant of Example 1 was added, and the formula of the shampoo is shown in Table 7.

[0083] Table 7 Hair cuticle repair shampoo

[0084] ;

[0085] The shampoo formula of Table 7 was replaced with the product of Example 1. The formula is as follows:

[0086] Table 8 Shampoo with Example 1

[0087] ;

[0088] Three hair strands of the same hair quality were taken, one as a blank control, and the other two were washed with the above hair cuticle repair shampoo and the shampoo with the composition of Example 1, respectively. Then the three groups of hair strands were placed under ultraviolet conditions for 48 h. The cut hair was taken with tweezers to fix the hair sample on a sample stage with conductive glue, gold spraying was performed, and cross-section slices were made, and the appropriate magnification was selected to observe the neatness and curling degree of the hair cuticle, and the damage repair of the hair was evaluated.

[0089] After 48 h of treatment under ultraviolet irradiation, the micro-morphology of the hair was observed by scanning electron microscope, and the results are shown in Figures 1, 2, and 3, which are blank control group, Example 1, and Example 2, respectively. As can be seen from the figures, the hair of the control group shows local cracking on the surface of the hair cuticle, the hair treated with the hair cuticle repair shampoo prepared with the surfactant of Example 1 has a smooth surface, and the hair treated with the shampoo prepared with Example 2 has no obvious repair effect, and the surface is still obviously cracked. By comparison, it is found that the product of the application can effectively protect the hair from light damage, and has good repair effect on the hair.

[0090] Based on the above performance evaluation data, it can be seen that the Gemini surfactant of the application has better emulsification, dispersion, foaming and stable foaming performance than the commercial product or typical competitor, and has better emulsification stability, dispersion stability and foaming effect stability. More importantly, the product of the application has good repair effect on the light-damaged hair cuticle.

[0091] The above is only a preferred embodiment of the application, and it should be noted that for those skilled in the art, without departing from the principles of the application, some modifications or equivalent replacements can be made to the technical solutions, and these modifications or equivalent replacements should also be considered as the protection scope of the application.

Claims

1. A Gemini surfactant characterized in that, The surfactant is prepared by reacting fatty acyl halide with L-cystine in a water and organic solvent mixture to produce a Gemini surfactant containing multiple amide groups and carboxyl groups.

2. The Gemini surfactant of claim 1, characterized in that, The surfactant structure general formula is: Formula I; In formula I, X is a hydrogen atom, an alkali metal, an alkaline earth metal, an amine, or a basic amino acid; C n H 2n+1 is a C7-C 21 saturated or unsaturated hydrocarbon group, which can or can not contain a branch.

3. The Gemini surfactant according to claim 2, wherein, said C7-C 21 Saturated or unsaturated hydrocarbyl groups are single or mixed carbon chains, including but not limited to lauryl, myristyl or coco.

4. The Gemini surfactant according to claim 2, wherein, The alkali metal includes but is not limited to sodium, potassium; the alkaline earth metal includes but is not limited to calcium, magnesium; the amine includes but is not limited to triethanolamine, triethylamine; the basic amino acid includes but is not limited to arginine.

5. A process for the preparation of the Gemini surfactant according to any one of claims 1 to 4, characterized in that, The method comprises the following steps: 1) Dissolve L-cystine in a water / isopropanol mixture, adjust the pH to 10 with lye, and make it clear; 2) Add lauroyl halide dropwise to the reaction system, and add lye as an acid-binding agent at the same time, controlling the temperature to 10-30℃ during the process; 3) Continue to add lye until the amount of alkali added reaches 4.0 eq; 4) After the reaction is completed, filter the reaction liquid to obtain lauroyl cystine or its salt crude product, and recrystallize the crude product using ethanol / water.

6. A product for personal washing and grooming characterized in that, The product comprises personal washing and care products, personal skin care products, household cleaning products, and household care products.

7. The product of claim 6, wherein, The amount of Gemini surfactant in the product is not less than 0.004wt% based on the total mass of the product, preferably 0.004-7.0wt%.

8. The product of claim 6, wherein, The product comprises personal washing and care products, personal skin care products, household cleaning products, and household care products.

9. The product of claim 7, wherein, The personal washing and care products include but are not limited to one or more of shampoo, hair conditioner, body wash, hand wash, hand soap, scrub, facial cleanser, emulsified skin care product, oil-based skin care product, water-based spray skin care product, paste and gel skin care product, toothpaste, mouthwash, laundry detergent, fabric softener, and dishwashing detergent.

10. The product of claim 6, wherein, The product comprises personal washing and care products, personal skin care products, household cleaning products, and household care products. The product comprises personal washing and care products, personal skin care products, household cleaning products, and household care products.

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