Selenium disulfide slurry, anti-dandruff treatment product, method of making and use

Abstract

This application discloses a selenium disulfide slurry, an anti-dandruff care product, a preparation method, and its application. The provided selenium disulfide slurry, by mass fraction, comprises 5%–50% selenium disulfide, 15%–50% wetting agent, 10%–25% surfactant, 2%–15% primary anti-discoloration agent, 2%–10% secondary anti-discoloration agent, 20%–50% suspending agent, and 0%–46% water, and 0.3%–0.8% preservative. The primary anti-discoloration agent comprises colloidal sulfur, and the secondary anti-discoloration agent comprises hymenium chloride. The provided selenium disulfide slurry exhibits good dispersibility, high stability, and is not prone to discoloration.

Description

Technical Field

[0001] This application belongs to the field of daily chemical products technology, and relates to selenium disulfide powder paste, anti-dandruff care products, preparation methods and applications. Background Technology

[0002] Selenium disulfide (SeS2) is an orange-red to orange-yellow crystalline powder, insoluble in water and most organic solvents. Due to its excellent antibacterial, anti-seborrheic, and antifungal activities, especially its significant inhibitory effect on Malassezia, selenium disulfide is widely used as a functional additive in daily chemical products, commonly found in anti-dandruff shampoos, scalp care products, and related topical washes to improve scalp-related problems such as dandruff and seborrheic dermatitis. However, currently commercially available or commonly used selenium disulfide powder raw materials suffer from poor dispersibility, poor stability, and easy discoloration in practical applications, leading to a decrease in the activity of selenium disulfide. Summary of the Invention

[0003] Therefore, it is necessary to provide a selenium disulfide slurry with good dispersibility, high stability, and resistance to discoloration, as well as an anti-dandruff care product, its preparation method, and its application.

[0004] In some embodiments, a selenium disulfide slurry is provided, comprising, by mass fraction, 5%~50% selenium disulfide, 15%~50% wetting agent, 10%~25% surfactant, 2%~15% first anti-discoloration agent, 2%~10% second anti-discoloration agent, 20%~50% suspending agent, 0%~46% water, and 0.3%~0.8% preservative, wherein the first anti-discoloration agent comprises colloidal sulfur, the second anti-discoloration agent comprises hyaluronic acid chloride, and the wetting agent comprises one or both of glycerol and caprylic / capric triglycerides.

[0005] In some embodiments, the provided selenium disulfide slurry satisfies one or more of the following characteristics:

[0006] (1) The surfactant comprises one or more of the following: cocamidopropyl betaine, cocamidopropyl hydroxysulfonate betaine, lauroamide propyl betaine, sodium cocoamphoacetate, alkyl glucoside and CMMEA methyl monoethanolamide.

[0007] (2) The preservative comprises one or more of phenoxyethanol, ethylhexylglycerin, sodium benzoate and octyl glycol;

[0008] (3) The particle size of the sulfur particles in the colloidal sulfur is 20 nm to 200 nm; and

[0009] (4) The method for preparing the colloidal sulfur includes the following steps:

[0010] The colloidal sulfur is prepared by mixing sulfur with an aqueous solution containing a dispersant and wet milling; wherein the mass fraction of the dispersant in the aqueous solution containing the dispersant is 5wt% to 15wt%, the mass ratio of the sulfur to the aqueous solution containing the dispersant is 1:(3 to 5), the wet milling time is 2h to 6h, and the dispersant contains gum arabic.

[0011] In some embodiments, the provided selenium disulfide slurry contains one or both of tristearate and emulsified hydrogenated castor oil as the suspending agent.

[0012] Optionally, the method for preparing the emulsified hydrogenated castor oil includes the following steps: mixing hydrogenated castor oil with cocamidomethyl monoethanolamine (cocamidomethyl MEA) under first heating and first stirring conditions to prepare an oil phase;

[0013] Aqueous phase was prepared by mixing water and disodium lauryl sulfosuccinate, and then adding cocamidopropyl betaine.

[0014] Under the conditions of second heating and second stirring of the aqueous phase, the oil phase is added to the aqueous phase and dispersed and crystallized under the conditions of third stirring to prepare the emulsified hydrogenated castor oil; wherein the temperatures of the first heating and the second heating are each independently 80℃~90℃, the speeds of the first stirring and the second stirring are each independently 300rpm~800rpm, and the speed of the third stirring is 3000rpm~8000rpm.

[0015] In some embodiments, the method for preparing selenium disulfide slurry includes the following steps:

[0016] The preheated wetting agent, surfactant, and suspending agent are mixed together, and selenium disulfide, the first anti-discoloration agent, and the second anti-discoloration agent are added. The mixture is then ground under stirring conditions, and water is added to mix, thus preparing the selenium disulfide slurry.

[0017] In some embodiments, the provided method for preparing selenium disulfide slurry satisfies one or more of the following conditions:

[0018] (1) The preheating temperature is 35℃~40℃;

[0019] (2) The stirring speed is 2000 r / min to 3000 r / min, and the grinding time is 15 min to 20 min; and

[0020] (3) In the step of adding water for mixing, stir for 3 min to 5 min at 100 r / min to 200 r / min.

[0021] In some embodiments, the method for preparing selenium disulfide slurry provides a solid particle size D90 ≤ 15 μm in the prepared selenium disulfide slurry.

[0022] In some embodiments, the selenium disulfide slurry or the selenium disulfide slurry prepared by the preparation method is provided for use in the preparation of anti-dandruff care products.

[0023] In some embodiments, an anti-dandruff care product is provided, comprising the selenium disulfide slurry or the selenium disulfide slurry prepared by the preparation method described above.

[0024] In some embodiments, the selenium disulfide powder in the provided dandruff care product has a mass fraction of 1% to 5%.

[0025] In some embodiments, the provided dandruff care products include at least one of anti-dandruff shampoo, scalp serum, and 2-in-1 shampoo and conditioner.

[0026] In the aforementioned selenium disulfide powder slurry, the wetting agent can better dissolve and disperse selenium disulfide particles, preventing particle agglomeration, while improving the skin feel of the slurry and reducing the risk of scalp irritation in the final shampoo. When used with water, it can optimize the grinding process and improve the uniformity of the slurry. The surfactant can further enhance the surface wettability and interfacial solubility of selenium disulfide particles, and has the functions of emulsification, dispersion, charge stabilization and suspension assistance. It can reduce the surface tension between particles, weaken the tendency of particle agglomeration, and work together with the glycerin wetting system and the suspending agent stabilizing system to further improve the dispersion uniformity of selenium disulfide particles in the aqueous system, effectively avoiding secondary agglomeration of particles during grinding, storage and compounding. At the same time, it can improve the interfacial compatibility between the slurry and the shampoo matrix, improve the dispersion stability of selenium disulfide in the washing and care system, reduce precipitation and stratification, and take into account both the skin feel and scalp gentleness of the product. The suspending agent effectively maintains the physical suspension stability of the slurry, preventing selenium disulfide particles from settling and separating. The first anti-discoloration agent inhibits discoloration caused by redox reactions of selenium disulfide by regulating the valence state of sulfur. The second anti-discoloration agent forms a barrier protective layer on the surface of selenium disulfide particles, synergistically enhancing the antioxidant and anti-discoloration stability of the system, blocking external oxidizing factors from contacting selenium disulfide particles, and inhibiting browning and color deterioration. This results in well-dispersible, highly stable, and less prone-to-discoloration selenium disulfide slurry, preventing the degradation of selenium disulfide activity.

[0027] The provided selenium disulfide powder paste can be applied to anti-dandruff care products to achieve efficient, gentle, and stable scalp care results. No new large-scale warehousing equipment is required during use, reducing production costs for enterprises. It has strong process adaptability and can be directly integrated into the final preparation stage of daily chemical production lines, demonstrating significant industrial application value. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments and examples of this application, and to more completely understand this application and its beneficial effects, the accompanying drawings used in the description of the embodiments or examples will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of this application. Those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0029] Figure 1 The results of transmitted polarized light detection are for the selenium disulfide slurry of Example 1;

[0030] Figure 2 The results of transmitted polarized light detection of selenium disulfide slurry in Example 12;

[0031] Figure 3 The results of transmitted polarized light detection are for the selenium disulfide slurry of Comparative Example 1-1.

[0032] Figure 4 The results of transmitted polarized light detection are for the selenium disulfide slurry of Comparative Examples 1-2.

[0033] Figure 5 The results of transmitted polarized light detection are for the selenium disulfide slurry of Comparative Example 2-1.

[0034] Figure 6 The results of transmitted polarized light detection are for the selenium disulfide slurry in Comparative Example 2-2.

[0035] Figure 7 The results of transmitted polarized light detection are for the selenium disulfide slurry of Comparative Examples 2-3.

[0036] Figure 8 The results of transmitted polarized light detection are for the selenium disulfide slurry of Comparative Example 3-1.

[0037] Figure 9 The results of transmitted polarized light detection are for the selenium disulfide slurry of Comparative Example 3-2.

[0038] Figure 10 The results of transmitted polarized light detection are for the selenium disulfide slurry in Comparative Example 3-3.

[0039] Figures 1-10 In the image, the scale bar is 500μm for a 50x magnification, 200μm for a 100x magnification, 100μm for a 200x magnification, and 50μm for a 500x magnification. Detailed Implementation

[0040] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0041] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0043] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:

[0044] The terms "and / or," "or / and," and "and / or" as used in this application encompass any one of two or more related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected using at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that in this application, the technical solution undoubtedly includes solutions connected by "logical AND," and also undoubtedly includes solutions connected by "logical OR." For example, "A and / or B" includes three parallel solutions: A, B, and "a combination of A and B."

[0045] In this application, the terms "multiple", "various", "multiple times", "multi-dimensional", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more than or equal to two.

[0046] The terms “combinations thereof,” “any combination thereof,” and “any combination thereof” as used in this application include all suitable combinations of any two or more of the listed items.

[0047] In this application, the term "suitable" as used in "suitable combination", "suitable method", "any suitable method", etc., refers to the ability to implement the technical solution of this application, solve the technical problem of this application, and achieve the expected technical effect of this application.

[0048] In this application, terms such as "preferred," "better," "more suitable," and "ideal" are merely used to describe implementation methods or embodiments that achieve better results, and should be understood not to limit the scope of protection of this application.

[0049] In this application, terms such as "further," "even further," and "particularly" are used to describe purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0050] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0051] In this invention, the terms "first aspect," "second aspect," "third aspect," and "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," and "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0052] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0053] In this application, numerical intervals (i.e., numerical ranges) are involved. Unless otherwise specified, the selected numerical distributions within the aforementioned numerical intervals are considered continuous and include the two endpoints (i.e., the minimum and maximum values) of the numerical range, as well as every value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints. In this document, this is equivalent to directly listing every integer. For example, if t is an integer selected from 1 to 10, it means that t is any integer selected from the group of integers consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Furthermore, when multiple ranges are provided to describe features or characteristics, these ranges can be merged. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0054] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0055] In this application, % (w / w) and wt% both represent weight percentage, % (v / v) refers to volume percentage, and % (w / v) refers to mass-volume percentage.

[0056] In this application, "room temperature" generally refers to 5℃~30℃, and more preferably 25±5℃.

[0057] In this application, D50 in the context refers to the median particle size, which represents the particle size corresponding to a cumulative particle size distribution percentage of 50%, and characterizes the average particle size of selenium disulfide particles.

[0058] In this application, D90 in the context refers to the upper limit particle size, which represents the particle size corresponding to when the cumulative particle size distribution percentage of the powder reaches 90%, characterizing the maximum particle size level of the vast majority of particles in the system.

[0059] The detection methods for D50 and D90 are as follows: The detection is carried out by laser diffraction particle size analyzer (wet method). The selenium disulfide slurry is dispersed in the dispersion medium, and the sample is injected by wet method. The particle size distribution is analyzed by laser diffraction scattering signal.

[0060] In this application, the mass fraction of caprylic acid in the caprylic / capric triglyceride is 55% to 65%, and the mass fraction of capric acid is 35% to 45%.

[0061] In some embodiments, a selenium disulfide slurry is provided, comprising, by mass fraction, 5%~50% selenium disulfide, 15%~50% wetting agent, 10%~25% surfactant, 2%~15% first anti-discoloration agent, 2%~10% second anti-discoloration agent, 20%~50% suspending agent, 0%~46% water, and 0.3%~0.8% preservative, wherein the first anti-discoloration agent comprises colloidal sulfur, the second anti-discoloration agent comprises hyaluronic acid chloride, and the wetting agent comprises one or both of glycerol and caprylic / capric triglycerides.

[0062] The discoloration of selenium disulfide (SeS2) is essentially due to sulfur loss, selenium oxidation, and the formation of low-valence selenium / elemental selenium. Colloidal sulfur locks in the structure of selenium disulfide through sulfur balance, reducing protection, inhibition of sulfur precipitation, and isolation from oxidation, thus preventing the decomposition and discoloration of selenium disulfide.

[0063] Wetting agents can better dissolve and disperse selenium disulfide particles, preventing particle agglomeration, while improving the skin feel of the powder and reducing the risk of scalp irritation in the final shampoo; when used with water, they can optimize the grinding process and improve the uniformity of the powder.

[0064] In the stable system formed by surfactants and suspending agents, surfactants work synergistically with glycerin and suspending agents to further improve the dispersibility of selenium disulfide particles, preventing particle agglomeration after grinding. At the same time, they help improve the compatibility between the slurry and the final shampoo matrix. If surfactants are removed, the slurry will be unevenly dispersed and particles will settle in the final product. Suspension agents can effectively maintain the suspension stability of the slurry and prevent selenium disulfide particles from settling and stratifying. If suspending agents are removed, the slurry will show obvious settling within 24 hours and cannot maintain a uniform state for a long time. When the two work synergistically, the slurry can be kept stratified and settled for 24 hours, and its stability is significantly better than that of a single component.

[0065] The combination of two anti-color change agents produces a synergistic effect, which can significantly inhibit the oxidative color change of selenium disulfide compared with a single anti-color change agent or no anti-color change agent: without the first anti-color change agent or without the second anti-color change agent, the slurry will darken significantly within 24-48 hours; without both the first and second anti-color change agents, the slurry will turn brown severely within 24 hours and lose its usability.

[0066] The provided selenium disulfide slurry exhibits uniform particle dispersion, without agglomeration, stratification, or sedimentation, and is not prone to browning. The provided selenium disulfide slurry meets mildness standards; through the synergistic effect of wetting agents and surfactants, the irritation of selenium disulfide is reduced. It has passed the scalp patch test in terminal shampoos. Compared to solutions that replace wetting agents or lack stabilizing components, the irritation is significantly reduced.

[0067] Understandably, the selenium disulfide slurry provided may contain 5% to 50% selenium disulfide by mass fraction, for example, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc., or may be a range of any two of the aforementioned values.

[0068] Understandably, the wetting agent in the provided selenium disulfide slurry can be 15% to 50% by mass fraction, for example, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc., or it can be any range of two of the aforementioned values.

[0069] Understandably, the provided selenium disulfide slurry may contain surfactants of 10% to 25% by mass fraction, for example, 10%, 15%, 20%, 25%, etc., or any range of the aforementioned two values.

[0070] Understandably, the selenium disulfide slurry provided may contain 2% to 15% selenium disulfide powder as the first anti-coloring agent, for example, 2%, 4%, 6%, 8%, 10%, 12%, 14%, 15%, etc., or any range of the two values ​​mentioned above.

[0071] Understandably, the selenium disulfide slurry provided may contain a second anti-coloring agent of 2% to 10% by mass fraction, for example, 2%, 4%, 6%, 8%, 10%, etc., or any range of the aforementioned two values.

[0072] Understandably, the selenium disulfide slurry provided may contain 20% to 50% suspending agent by mass fraction, for example, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc., or any range of the aforementioned two values.

[0073] Understandably, the selenium disulfide slurry provided may contain water in the range of 0% to 46% by mass, for example, 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 46%, etc., or any range of the two values ​​mentioned above.

[0074] Understandably, the selenium disulfide slurry provided may contain 0.3% to 0.8% preservative by mass fraction, for example, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, etc., or any range of two of the aforementioned values.

[0075] In some embodiments, the provided selenium disulfide slurry contains a surfactant comprising one or more of cocamidopropyl betaine, cocamidopropyl hydroxysulfonate, lauroamide propyl betaine, sodium cocamidopropyl acetate, alkyl glucoside, and CMMEA (cocamide monoethanolamide).

[0076] In some embodiments, the provided selenium disulfide slurry contains one or more of phenoxyethanol, ethylhexylglycerin, sodium benzoate, and octyl glycol as the preservative.

[0077] In some embodiments, the provided selenium disulfide slurry contains sulfur particles with a particle size of 20 nm to 200 nm, such as 20 nm, 50 nm, 100 nm, 150 nm, 200 nm, etc., or a range composed of any two of the aforementioned values.

[0078] In some embodiments, the provided selenium disulfide slurry includes the following steps in its preparation method for colloidal sulfur:

[0079] The colloidal sulfur is prepared by mixing sulfur with an aqueous solution containing a dispersant and wet milling; wherein the mass fraction of the dispersant in the aqueous solution containing the dispersant is 5wt% to 15wt%, the mass ratio of the sulfur to the aqueous solution containing the dispersant is 1:(3 to 5), the wet milling time is 2 to 6 hours, and the dispersant contains gum arabic.

[0080] In some embodiments, the provided selenium disulfide slurry contains one or both of tristearate and emulsified hydrogenated castor oil as the suspending agent.

[0081] In some embodiments, the method for preparing the emulsified hydrogenated castor oil includes the following steps: mixing hydrogenated castor oil with cocamidomethyl monoethanolamine (cocamidomethyl MEA) under first heating and first stirring conditions to prepare an oil phase;

[0082] Aqueous phase was prepared by mixing water and disodium lauryl sulfosuccinate, and then adding cocamidopropyl betaine.

[0083] Under the conditions of second heating and second stirring of the aqueous phase, the oil phase is added to the aqueous phase and dispersed and crystallized under the conditions of third stirring to prepare the emulsified hydrogenated castor oil; wherein the temperatures of the first heating and the second heating are each independently 80℃~90℃, the speeds of the first stirring and the second stirring are each independently 300rpm~800rpm, and the speed of the third stirring is 3000rpm~8000rpm.

[0084] In some embodiments, the method for preparing selenium disulfide slurry includes the following steps:

[0085] The preheated wetting agent, surfactant, and suspending agent are mixed together, and selenium disulfide, the first anti-discoloration agent, and the second anti-discoloration agent are added. The mixture is then ground under stirring conditions, and water is added to mix, thus preparing the selenium disulfide slurry.

[0086] In some embodiments, the preheating temperature in the provided method for preparing selenium disulfide slurry is 35°C to 40°C.

[0087] In some embodiments, the method for preparing selenium disulfide slurry involves stirring at a speed of 2000 r / min to 3000 r / min and grinding for 15 min to 20 min.

[0088] In some embodiments, the method for preparing selenium disulfide slurry includes mixing with water for 3 to 5 minutes at a speed of 100 to 200 rpm.

[0089] In some embodiments, the method for preparing selenium disulfide slurry provides a solid particle size D90 ≤ 15 μm in the prepared selenium disulfide slurry.

[0090] In some embodiments, the selenium disulfide slurry or the selenium disulfide slurry prepared by the preparation method is provided for use in the preparation of anti-dandruff care products.

[0091] An exemplary method for preparing an anti-dandruff care product includes the following steps: mixing the selenium disulfide slurry with excipients suitable for daily chemical products.

[0092] In some embodiments, an anti-dandruff care product is provided, comprising the selenium disulfide slurry or the selenium disulfide slurry prepared by the preparation method described above.

[0093] For example, anti-dandruff care products may also include one or more of solvents, surfactants, thickeners, suspending agents, emulsifiers, preservatives, pH adjusters, chelating agents, fragrances, and colorants.

[0094] In some embodiments, the raw materials for preparing the dandruff care product include the aforementioned selenium disulfide slurry.

[0095] In some embodiments, the dandruff care product includes a non-solvent component of selenium disulfide powder.

[0096] In this application, unless otherwise specified, "non-solvent components" in selenium disulfide slurry refers to components in selenium disulfide slurry other than solvent components (such as water). Typically, when selenium disulfide slurry is concentrated, at least a portion of the solvent components can evaporate, while the non-solvent components are retained in the concentrate.

[0097] In some embodiments, the selenium disulfide powder in the provided dandruff care product has a mass fraction of 1% to 5%.

[0098] In some embodiments, the provided dandruff care products include at least one of anti-dandruff shampoo, scalp serum, and 2-in-1 shampoo and conditioner products.

[0099] The provided dandruff care products show no stratification, discoloration, or sedimentation during 7-day, 14-day, and 30-day storage periods, and maintain good condition even after 30 days of constant temperature storage at 35℃; the dandruff removal performance is stable, with long-term stable dandruff removal effect and no significant attenuation.

[0100] The following are specific embodiments. They are intended to provide a more detailed description of this application to help those skilled in the art and researchers better understand it. The technical conditions described do not constitute any limitation on this application. Any modifications made within the scope of the claims of this application are protected by the claims.

[0101] Unless otherwise stated, all raw materials and reagents used in the following examples are commercially available or can be prepared by known methods. Experimental methods not specifying particular conditions in the examples were performed under conventional conditions, such as those described in literature, books, or methods recommended by the manufacturer.

[0102] In the following examples and comparative examples, "CAB" stands for "cocamidopropyl betaine".

[0103] In the following examples and comparative examples, "Suspension Agent 1" is emulsified hydrogenated castor oil, and its preparation method is as follows:

[0104] 1. Preparation of the oil phase: Hydrogenated castor oil solid was mixed with cocoamide MEA and heated to 85°C while stirring until it was completely melted into a yellow transparent oily liquid;

[0105] 2. Aqueous phase preparation: Add deionized water and disodium lauryl sulfosuccinate, stir for 5 minutes until completely dissolved, then add CAB and stir for 5 minutes until completely dissolved;

[0106] 3. At 85℃, slowly add the oil phase to the aqueous phase while keeping the aqueous phase stirred at high speed. After adding the oil phase, keep stirring at high speed for 30 minutes to fully disperse the hydrogenated castor oil into tiny droplets.

[0107] 4. Cool down and crystallize to prepare emulsified hydrogenated castor oil.

[0108] In the following examples and comparative examples, "Suspension Agent 2" is trihydroxystearin.

[0109] The preparation method of "colloidal sulfur" in the following examples and comparative examples is as follows: Gum arabic is dissolved in water to prepare a 10wt% gum arabic aqueous solution. Sulfur powder is added to the gum arabic aqueous solution at a mass ratio of 1:4. The mixture is then wet-milled for 5 hours until the sulfur particles are ground to 20-200 nm. This allows the dispersant gum arabic to coat the sulfur particles and form water-based colloidal sulfur. Coarse particles are removed by filtration to obtain the finished product.

[0110] Example 1

[0111] This embodiment provides a selenium disulfide slurry, which, by mass fraction, contains the following components: 20% selenium disulfide, 25% glycerol, 20% CAB, 6% colloidal sulfur, 4% hymexazol, 20% suspending agent 1, and 5% water.

[0112] The preparation method of selenium disulfide slurry is as follows:

[0113] 1. Raw material pretreatment: Weigh each component according to the above mass fractions, and pass selenium disulfide, colloidal sulfur, and hymenium chloride through an 80-100 mesh sieve to remove impurities and large particles; preheat glycerol, CAB, and suspending agent 1 to 35°C for later use.

[0114] 2. Premixing: Add the preheated glycerin, CAB and suspending agent 1 to the mixing tank of the grinder in sequence. Control the stirring speed at 400 r / min and the stirring time at 7 min to obtain a uniformly mixed base liquid.

[0115] 3. Preparation by grinding: Add sieved selenium disulfide, colloidal sulfur, and hymenium chloride to the base liquid in batches, control the feeding rate at 780 g / min, turn on the grinder, the grinding speed of the grinder is 2500 r / min, the grinding time is 20 min, until the particle size of the slurry D90 is ≤10 μm.

[0116] 4. Immediate mixing: After grinding, add 5% water directly to the discharge port of the grinder and stir at a low speed of 150r / min for 5 minutes to obtain a 20% selenium disulfide slurry.

[0117] Example 2

[0118] This embodiment provides a selenium disulfide slurry, which, by mass fraction, contains the following components: 20% selenium disulfide, 15% glycerol, 20% CAB, 6% colloidal sulfur, 4% hymexazol, 20% suspending agent 1, and 15% water.

[0119] The preparation method is the same as in Example 1.

[0120] Example 3

[0121] This embodiment provides a selenium disulfide slurry, which, by mass fraction, contains the following components: 20% selenium disulfide, 45% glycerol, 5% CAB, 6% colloidal sulfur, 4% hymexazol, and 20% suspending agent 1.

[0122] The preparation method is the same as in Example 1.

[0123] Example 4

[0124] This embodiment provides a selenium disulfide slurry, which, by mass fraction, contains the following components: 20% selenium disulfide, 25% glycerol, 10% CAB, 6% colloidal sulfur, 4% hymexazol, 20% suspending agent 1, and 15% water.

[0125] The preparation method is the same as in Example 1.

[0126] Example 5

[0127] This embodiment provides a selenium disulfide slurry, which, by mass fraction, contains the following components: 20% selenium disulfide, 25% glycerol, 25% CAB, 6% colloidal sulfur, 4% hymexazol, and 20% suspending agent 1.

[0128] The preparation method is the same as in Example 1.

[0129] Example 6

[0130] This embodiment provides a selenium disulfide slurry, which, by mass fraction, contains the following components: 20% selenium disulfide, 25% glycerol, 20% cocamidopropyl hydroxysulfonate betaine, 6% colloidal sulfur, 4% hymexazol, 20% suspending agent 1, and 5% water.

[0131] The preparation method is the same as in Example 1.

[0132] Example 7

[0133] This embodiment provides a selenium disulfide slurry, which, by mass fraction, contains the following components: 20% selenium disulfide, 25% glycerol, 20% lauramide propyl betaine, 6% colloidal sulfur, 4% hyaluronic acid chloride, 20% suspending agent 1, and 5% water.

[0134] The preparation method is the same as in Example 1.

[0135] Example 8

[0136] This embodiment provides a selenium disulfide slurry, which, by mass fraction, contains the following components: 20% selenium disulfide, 25% glycerol, 20% sodium cocoamphoacetate, 6% colloidal sulfur, 4% hymexazolium chloride, 20% suspending agent 1, and 5% water.

[0137] The preparation method is the same as in Example 1.

[0138] Example 9

[0139] This embodiment provides a selenium disulfide slurry, which, by mass fraction, contains the following components: 20% selenium disulfide, 25% glycerol, 20% alkyl glucoside, 6% colloidal sulfur, 4% hyaluronic acid chloride, 20% suspending agent 1, and 5% water.

[0140] The preparation method is the same as in Example 1.

[0141] Example 10

[0142] This embodiment provides a selenium disulfide slurry, which, by mass fraction, contains the following components: 20% selenium disulfide, 25% glycerol, 20% CMMEA (cocoyl methyl monoethanolamide), 6% colloidal sulfur, 4% hyaluronic acid chloride, 20% suspending agent 1, and 5% water.

[0143] The preparation method is the same as in Example 1.

[0144] Example 11

[0145] This embodiment provides a selenium disulfide slurry, which, by mass fraction, contains the following components: 20% selenium disulfide, 25% glycerol, 20% CAB, 6% colloidal sulfur, 4% hymexazol, 20% suspending agent 2, and 5% water.

[0146] The preparation method is the same as in Example 1.

[0147] Example 12

[0148] This embodiment provides a selenium disulfide slurry with a formula and preparation method similar to that of Example 1. The difference is that glycerol is replaced with oil-soluble octanoic acid / capric triglyceride (GTCC), and other conditions are the same as in Example 1.

[0149] Comparative Example 1-1

[0150] This comparative example provides a selenium disulfide slurry, with a formulation and preparation method similar to that of Example 1, except that propylene glycol is used instead of glycerol, and other conditions are the same as in Example 1.

[0151] Comparative Examples 1-2

[0152] This comparative example provides a selenium disulfide slurry, with a formulation and preparation method similar to that of Example 1, except that deionized water is used instead of glycerol, and other conditions are the same as in Example 1.

[0153] Comparative Examples 1-3

[0154] This comparative example provides a selenium disulfide slurry, which, by mass fraction, contains the following components: 20% selenium disulfide, 5% glycerol, 20% CAB, 6% colloidal sulfur, 4% hymexazol, 20% suspending agent 1, and 25% water.

[0155] The preparation method is the same as in Example 1.

[0156] Comparative Examples 1-4

[0157] This comparative example provides a selenium disulfide slurry, which, by mass fraction, contains the following components: 20% selenium disulfide, 65% glycerol, 3% CAB, 6% colloidal sulfur, 4% hymexazol, and 2% suspending agent 1.

[0158] The preparation method is the same as in Example 1.

[0159] Comparative Example 2-1

[0160] This comparative example provides a selenium disulfide slurry with a formulation and preparation method similar to that of Example 1, except that all CAB is replaced with an equal amount of water, while other conditions are the same as in Example 1.

[0161] Comparative Example 2-2

[0162] This comparative example provides a selenium disulfide slurry with a formulation and preparation method similar to that of Example 1, except that the suspending agent is completely replaced with an equal amount of water, while other conditions are the same as in Example 1.

[0163] Comparative Examples 2-3

[0164] This comparative example provides a selenium disulfide slurry with a formulation and preparation method similar to that of Example 1, except that CAB and the suspending agent are all replaced with an equal amount of water, while other conditions are the same as in Example 1.

[0165] Comparative Examples 2-4

[0166] This comparative example provides a selenium disulfide slurry, which, by mass fraction, contains the following components: 20% selenium disulfide, 25% glycerol, 5% CAB, 6% colloidal sulfur, 4% hymexazol, 20% suspending agent 1, and 20% water.

[0167] The preparation method is the same as in Example 1.

[0168] Comparative Example 3-1

[0169] This comparative example provides a selenium disulfide slurry with a formulation and preparation method similar to that of Example 1, except that all colloidal sulfur is replaced with an equal amount of water, while other conditions are the same as in Example 1.

[0170] Comparative Example 3-2

[0171] This comparative example provides a selenium disulfide slurry with a formula and preparation method similar to that of Example 1, except that all of the hymex chloride is replaced with an equal amount of water, and other conditions are the same as in Example 1.

[0172] Comparative Example 3-3

[0173] This comparative example provides a selenium disulfide slurry with a formulation and preparation method similar to that of Example 1. The difference is that colloidal sulfur and hymenium chloride are completely replaced with an equal amount of water, while other conditions are the same as in Example 1.

[0174] Performance testing

[0175] 1. Detection Method

[0176] (1) Particle size distribution detection

[0177] The D50 and D90 particle size distributions of selenium disulfide slurry obtained by wet laser diffraction were determined. The particle size distribution was then measured after ultrasonic-assisted dispersion in an organic medium such as ethanol. The operating procedures were as follows:

[0178] First, the selenium disulfide slurry sample to be tested was diluted with ethanol as the dispersion medium and then dispersed thoroughly and uniformly using ultrasound. Subsequently, the dispersed sample suspension was injected into the sample cell of a wet laser particle size analyzer. The instrument measures the intensity and angle of the scattered light generated when the laser beam passes through the particle suspension, and uses Mie scattering theory to deduce the particle size distribution. The experimental results are shown in Table 1.

[0179] (2) Aggregation degree detection

[0180] The degree of agglomeration of selenium disulfide slurry was detected using a polarizing microscope. During the detection process, at magnifications of 100x, 200x, and 500x, crossed polarization mode was required, along with Köhler illumination to adjust the field of view and aperture stop to ensure clear visibility of the birefringence of the particles. The experimental results are shown in Table 1.

[0181] (3) Stability testing

[0182] The prepared selenium disulfide slurry was left to stand for 7, 14, and 30 days, and the stratification and discoloration of the slurry were observed. The experimental results are shown in Table 1.

[0183] (4) Performance test of the prepared shampoo

[0184] Prepare shampoo using the following method:

[0185] Add 55.47 parts of deionized water to a mixing tank, then add 0.2 parts of disodium EDTA and 0.2 parts of allantoin, and stir to dissolve and disperse at room temperature. Heat to 75–80°C, then add 15 parts of sodium lauryl ether sulfate (AES), 6 parts of sodium α-olefin sulfonate, 3.5 parts of coconut oil monoethanolamide (CMEA), and 6 parts of cocamidopropyl betaine sequentially to construct a stable anionic cleaning system. Cool to 50°C, then add 2.5 parts of emulsified hydrogenated castor oil and stir to disperse evenly. Continue cooling to below 45°C, then add 0.3 parts of pre-dispersed polyquaternium-10, 0.5 parts of polyquaternium-87, 0.4 parts of polyquaternium-7, and 0.25 parts of conditioning agent (manufactured by Guangzhou Gaoju Biotechnology Co., Ltd.). The mixture consists of diC14-15 alcohol carbonate and water, which are thoroughly mixed and introduced into the cationic conditioning system. The mixture is then cooled to below 40°C, and 5 parts of 20% selenium disulfide slurry, 1 part of pearlescent paste (LP3201 pearlescent paste, manufactured by Guangdong Liangpeng Biotechnology Co., Ltd., composed of water, ethylene glycol monostearate, sodium lauryl ether sulfate, and coconut oil monoethanolamide), 0.3 parts of D-panthenol, 0.1 parts of zinc pyrrolidone carboxylate, 0.05 parts of natural vitamin E, 0.03 parts of menthol, 0.35 parts of fragrance, and 0.4 parts of 1,3-dihydroxymethyl-5,5-dimethylhydantoin (DMDMH) are added. The pH is finely adjusted twice with 0.25 parts of citric acid, and finally, 0.2 parts of sodium chloride are added to adjust the viscosity of the system. After homogenization, the mixture is discharged. After homogenization and static stabilization, the prepared shampoo was subjected to layer stability, dandruff removal efficacy, oil control performance, antipruritic effect, and skin irritation patch test. The test methods are as follows, and the test results are shown in Table 2.

[0186] Layering stability test: The prepared shampoo was sealed and placed in a 52℃ constant temperature oven, while a room temperature control group was set up. The samples were left for 30 days to observe whether layering, water separation, precipitation, discoloration, odor, or other phenomena occurred, and to evaluate the storage stability of the system.

[0187] Dandruff-removing efficacy, oil-controlling performance, and anti-itch performance experiments: Volunteers with dandruff were divided into 23 groups of 50 people each. Each group of volunteers used the test sample shampoo twice a week. The dandruff level was scored by professional evaluators and the participants' self-reported scores. The changes in the amount and area of ​​dandruff before and after use were compared to evaluate the dandruff-removing effect of the sample. A skin oil meter was used to measure the scalp oil content in the T-zone of the participants' scalp before use and 4 hours and 8 hours after use. The changes in oil secretion were compared to evaluate the oil-controlling effect of the shampoo. The visual analog scale (VAS) was used to score the degree of itching. The itching level before and after use was compared to evaluate the anti-itch efficacy.

[0188] The evaluation criteria for dandruff removal are as follows:

[0189] Effective: No dandruff; Normal: A small amount of dandruff remains; Ineffective: No reduction in dandruff.

[0190] Dandruff removal rate (%) = (effective + average) / 50 × 100%.

[0191] Oil control evaluation criteria:

[0192] Effective: Not greasy; Average: Slightly greasy; Ineffective: Still very greasy.

[0193] Oil control rate (%) = (effective + general) / 50 × 100%.

[0194] Antipruritic evaluation criteria:

[0195] Effective: No itching; Moderate: Slight itching; Ineffective: Still very itchy.

[0196] Antipruritic rate (%) = (effective + average) / 50 × 100%.

[0197] Skin irritation patch test: A total of 30 participants were tested using a closed patch test method. The test substance was a 1% dilution of the shampoo end product. Approximately 0.020 mL to 0.025 mL of the test substance was placed in the patch applicator and applied to the flexor side of the forearm of the participants using hypoallergenic adhesive tape. The test substance was removed after 24 hours. Skin reactions were observed 48 hours after removal, and the results were recorded according to the skin reaction grading standards in the "Cosmetic Safety Technical Specifications" (2015 edition).

[0198] The number of people who experienced a Grade 1 or higher reaction was counted, and the percentage of people with a Grade 1 or higher reaction in the total number of people was calculated to obtain the adverse reaction rate of the patch test.

[0199] The criteria for determining the grade of patch testing are as follows: Grade 0: Negative reaction; Grade 1: Suspicious reaction, only weak erythema; Grade 2: Weak positive reaction (erythema reaction), erythema, infiltration, edema, and papules may be present; Grade 3: Strong positive reaction (herpes reaction), erythema, infiltration, edema, papules, and vesicles, and the reaction may extend beyond the test area; Grade 4: Very strong positive reaction (confluent herpes reaction), obvious erythema, severe infiltration, edema, confluent herpes, and the reaction extends beyond the test area.

[0200] 2. Test Results

[0201] Table 1 below shows the particle size of selenium disulfide in selenium disulfide slurry, as well as the test results for whether the selenium disulfide slurry agglomerates, changes color, or separates.

[0202] Table 1

[0203]

[0204] Table 2 below shows the results of the shampoo's layering, color change, dandruff removal rate, oil control rate, anti-itch rate, and patch test.

[0205] Table 2

[0206]

[0207] The degree of agglomeration of selenium disulfide slurry is as follows: Figures 1-10 As shown.

[0208] Based on Tables 1 and 2 above, and Figures 1-10 The test results shown indicate that:

[0209] The selenium disulfide slurry in Examples 1 and 12 was uniform, fine, and free of agglomeration, resulting in low irritation in the final shampoo (passing the patch test). Compared to Example 1, Comparative Example 1-1, which used propylene glycol instead of glycerin, showed weaker dispersion of the selenium disulfide slurry and slightly lower stability. Comparative Example 1-2, which used water instead of glycerin, resulted in coarse slurry particles agglomeration and increased irritation in the final shampoo, with Example 1 exhibiting the highest dandruff removal rate. This indicates that using glycerin and caprylic / capric triglycerides as wetting agents can improve particle dispersibility, reduce irritation, and optimize process compatibility. Compared to propylene glycol, using glycerin and caprylic / capric triglycerides as wetting agents can better dissolve and disperse selenium disulfide particles, preventing agglomeration, improving the slurry's feel, and reducing the risk of scalp irritation in the final shampoo. When used in combination with water, it can optimize the grinding process and improve the uniformity of the slurry. Compared with Example 1, the content of glycerol in Comparative Examples 1-3 was lower, while the content of glycerol in Comparative Examples 1-4 was higher. The dispersion effect of selenium disulfide slurry in Comparative Examples 1-3 and Comparative Examples 1-4 was weaker than that in Example 1.

[0210] Comparing Example 1 (containing CAB as a surfactant), Comparative Example 2-1 (using water instead of CAB), and Comparative Example 2-3 (using water instead of CAB and suspending agent), the selenium disulfide slurry of Example 1 was uniformly dispersed, showed good compatibility with the final shampoo matrix, and had no particle sedimentation. In Comparative Example 2-1, the selenium disulfide slurry showed severe particle agglomeration, uneven dispersion, and particle sedimentation in the final shampoo. In Comparative Example 2-3, the selenium disulfide slurry could not maintain uniformity and showed obvious stratification. This demonstrates that CAB and other surfactants can effectively improve particle dispersibility and matrix compatibility.

[0211] Comparing Example 1 (containing emulsified hydrogenated castor oil as a suspending agent), Comparative Example 2-2 (using water instead of a suspending agent), and Comparative Example 2-3 (using water instead of CAB and a suspending agent), the slurry in Example 1 showed no stratification or sedimentation; the slurry in Comparative Example 2-2 showed significant sedimentation within 24 hours of standing and could not maintain uniformity for a long time; the sedimentation and stratification in Comparative Example 2-3 were more severe, proving that the suspending agent can prevent particle sedimentation and stratification and maintain the uniformity of the slurry.

[0212] Compared with Example 1, Comparative Example 2-1, Comparative Example 2-2 and Comparative Example 2-3, the slurry stability of Example 1 is significantly better than that of the comparative examples lacking either CAB or suspending agent, and even better than that of Comparative Example 2-3 lacking both components. This proves that the two components work synergistically to achieve dual stability of "dispersion + suspension", improve the dispersibility and suspension stability of the slurry, and improve the overall stability of the slurry.

[0213] Comparing Example 1 (containing colloidal sulfur and hyaluronic acid), Comparative Example 3-1 (using water to replace colloidal sulfur), and 4-2 (using water to replace hyaluronic acid), the color difference of the slurry in Example 1 was close to the initial value within 24 hours, and there was no obvious color change after 7 days; Comparative Example 3-1 showed obvious color change within 24 hours; Comparative Example 3-2 showed slight color change from 24 to 48 hours, proving that the synergistic effect of the dual anti-color change agent combination is better than that of a single anti-color change agent.

[0214] Comparing Example 1 and Comparative Example 3-3 (using water instead of colloidal sulfur and hyaluronic acid), the slurry of Example 1 showed no significant discoloration after long-term storage (30 days); Comparative Example 3-3 showed severe browning within 24 hours, with a significant increase in color difference ΔE, accompanied by rapid decay of active ingredients, rendering the slurry unusable. This demonstrates that the dual-anti-discoloration system is the core of preventing slurry discoloration. The dual-anti-discoloration agent is crucial for inhibiting slurry discoloration; without it, the slurry cannot be used normally.

[0215] Example 1: The shampoo showed no separation, discoloration, or sedimentation during storage periods of 7 days, 14 days, and 30 days, and remained in good condition.

[0216] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0217] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention should be determined by the appended claims, and the specification and drawings can be used to interpret the content of the claims.

Claims

1. A selenium disulfide slurry, characterized in that, By mass fraction, it contains 5%~50% selenium disulfide, 15%~50% wetting agent, 10%~25% surfactant, 2%~15% first anti-color change agent, 2%~10% second anti-color change agent, 20%~50% suspending agent, 0%~46% water and 0.3%~0.8% preservative, wherein the first anti-color change agent contains colloidal sulfur, the second anti-color change agent contains hyaluronic acid chloride, and the wetting agent contains one or both of glycerol and caprylic / capric triglycerides.

2. The selenium disulfide slurry according to claim 1, characterized in that, It meets one or more of the following characteristics: (1) The surfactant comprises one or more of the following: cocamidopropyl betaine, cocamidopropyl hydroxysulfonate betaine, lauroamide propyl betaine, sodium cocoamphoacetate, alkyl glucoside and methyl monoethanolamide of cocoate; (2) The preservative comprises one or more of phenoxyethanol, ethylhexylglycerin, sodium benzoate and octyl glycol; (3) The particle size of the sulfur particles in the colloidal sulfur is 20 nm to 200 nm; and (4) The method for preparing the colloidal sulfur includes the following steps: The colloidal sulfur is prepared by mixing sulfur with an aqueous solution containing a dispersant and wet milling; wherein the mass fraction of the dispersant in the aqueous solution containing the dispersant is 5wt% to 15wt%, the mass ratio of the sulfur to the aqueous solution containing the dispersant is 1:(3 to 5), the wet milling time is 2h to 6h, and the dispersant contains gum arabic.

3. The selenium disulfide slurry according to claim 1 or 2, characterized in that, The suspending agent comprises one or both of tristearate and emulsified hydrogenated castor oil; Optionally, the method for preparing the emulsified hydrogenated castor oil includes the following steps: mixing hydrogenated castor oil with cocamidomethyl monoethanolamine under first heating and first stirring conditions to prepare an oil phase; Aqueous phase was prepared by mixing water and disodium lauryl sulfosuccinate, and then adding cocamidopropyl betaine. Under the conditions of second heating and second stirring of the aqueous phase, the oil phase is added to the aqueous phase and dispersed and crystallized under the conditions of third stirring to prepare the emulsified hydrogenated castor oil; wherein the temperatures of the first heating and the second heating are each independently 80℃~90℃, the speeds of the first stirring and the second stirring are each independently 300rpm~800rpm, and the speed of the third stirring is 3000rpm~8000rpm.

4. The method for preparing selenium disulfide slurry according to any one of claims 1 to 3, characterized in that, Includes the following steps: The preheated wetting agent, surfactant, and suspending agent are mixed together, and selenium disulfide, the first anti-discoloration agent, and the second anti-discoloration agent are added. The mixture is then ground under stirring conditions, and water is added to mix, thus preparing the selenium disulfide slurry.

5. The method for preparing selenium disulfide slurry according to claim 4, characterized in that, One or more of the following conditions must be met: (1) The preheating temperature is 35℃~40℃; (2) The stirring speed is 2000 r / min to 3000 r / min, and the grinding time is 15 min to 20 min; as well as (3) In the step of adding water for mixing, stir for 3 min to 5 min at 100 r / min to 200 r / min.

6. The method for preparing selenium disulfide slurry according to claim 4, characterized in that, The solid particles in the prepared selenium disulfide slurry have a particle size D90 ≤ 15 μm.

7. The use of the selenium disulfide slurry according to any one of claims 1 to 3 or the selenium disulfide slurry prepared by the preparation method according to any one of claims 4 to 6 in the preparation of anti-dandruff care products.

8. A dandruff care product, characterized in that, The product comprises the selenium disulfide slurry according to any one of claims 1 to 3 or the selenium disulfide slurry prepared by the preparation method according to any one of claims 4 to 6.

9. The dandruff care product according to claim 8, characterized in that, The selenium disulfide powder in the dandruff care product has a mass fraction of 1% to 5%.

10. The dandruff care product according to claim 8 or 9, characterized in that, The dandruff care products include at least one of the following: dandruff shampoo, scalp serum, and 2-in-1 shampoo and conditioner.

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