Composite bentonite and method for producing the same

Abstract

This application provides a composite bentonite and its preparation method. The preparation method includes: providing a mixed solution comprising bentonite powder, an organic cationic modifier, and water; reacting the mixed solution at a temperature of 60-80°C to obtain a suspension containing modified bentonite; drying the suspension containing modified bentonite to obtain modified bentonite, wherein the water content of the modified bentonite is less than 1.5%; pulverizing the modified bentonite to obtain organic cationic modified bentonite powder; mixing the organic cationic modified bentonite powder with an amino acid salt modifier and performing dry modification to obtain composite modified bentonite. The preparation method of this application produces a composite modified bentonite with good moisturizing properties and the ability to absorb oil, giving the composite modified bentonite the characteristics of oil control without drying.

Description

Technical Field

[0001] This application relates to the field of cosmetic raw material preparation, and in particular to composite bentonite and its preparation method. Background Technology

[0002] Bentonite is a clay mineral primarily composed of layered aluminosilicate montmorillonite. Its crystal structure consists of two layers of silicon-oxygen tetrahedra and one layer of aluminum-oxygen octahedra, with an aluminum-oxygen octahedron sandwiched between the two silicon-oxygen tetrahedra. The spaces between the unit crystal layers and between the two silicon-oxygen tetrahedra are filled with water molecules and exchangeable cations. Based on the type, content, and interlayer charge of the exchangeable cations, bentonite can be classified into sodium-based bentonite (alkaline clay), calcium-based bentonite (alkaline earth clay), and natural bleaching clay (acidic clay or acidic white clay). Calcium-based bentonite further includes calcium-sodium-based and calcium-magnesium-based bentonite, among others.

[0003] Bentonite possesses strong hygroscopic and swelling properties, capable of absorbing 8 to 15 times its own volume of water, with a volume expansion reaching several to 30 times its own weight. In aqueous media, it can disperse into gel-like and suspension-like states, and this solution exhibits certain viscosity, thixotropy, and lubricity. It has a strong cation exchange capacity and a certain adsorption capacity for various gases, liquids, and organic substances, with a maximum adsorption capacity of up to 5 times its own weight.

[0004] Bentonite's adsorption and cation exchange properties allow for the removal of toxins from edible oils, purification of gasoline and kerosene, and wastewater treatment. Its excellent water absorption and swelling properties, as well as its dispersing, suspending, and pulping abilities, make it suitable for drilling mud and flame retardancy (suspension fire extinguishing). It can also be used as a filler in the paper industry to optimize coating properties such as adhesion, hiding power, water resistance, and washability. However, bentonite's use in cosmetics requires combination with other strong oil-controlling and moisturizing substances to improve cosmetic comfort, thus limiting its widespread application and necessitating urgent improvement. Summary of the Invention

[0005] This application provides a composite bentonite and its preparation method, aiming to provide a cosmetic raw material with good moisturizing and oil-absorbing properties, namely composite bentonite, which has the characteristics of controlling oil without drying out the skin.

[0006] In a first aspect, embodiments of this application propose a method for preparing composite bentonite, comprising:

[0007] Provides a mixed solution comprising bentonite powder, organic cationic modifier, and water;

[0008] The mixed solution was reacted at a temperature of 60–80°C to obtain a suspension containing modified bentonite.

[0009] The modified bentonite is prepared by drying a suspension containing modified bentonite, wherein the water content of the modified bentonite is less than 1.5%.

[0010] Modified bentonite was pulverized to obtain organic cationic modified bentonite powder;

[0011] Organic cationic modified bentonite powder was mixed with an amino acid salt modifier and then dry modified to obtain composite modified bentonite.

[0012] According to one embodiment of this application, the organic cationic modifier includes one or more of the following: hydroxypropyltrimethylammonium chloride hyaluronic acid, locust bean gum hydroxypropyltrimethylammonium chloride, aralia elata hydroxypropyltrimethylammonium chloride, starch hydroxypropyltrimethylammonium chloride, panthenol-hydroxypropylstearyl dimethylammonium chloride, and dextran-hydroxypropyltrimethylammonium chloride.

[0013] According to one embodiment of this application, the mass ratio of bentonite powder to organic cationic modifier is 1:(0.8-1.2).

[0014] According to one embodiment of this application, the amino acid salt modifier includes one or more of disodium stearoyl glutamate, disodium lauroyl glutamate, disodium cocoyl glutamate, sodium lauroyl glutamate, sodium stearoyl glutamate, and sodium cocoyl glutamate.

[0015] According to one embodiment of this application, the mass ratio of amino acid salt modifier to organic cationic modified bentonite powder is (1-3):100.

[0016] According to one embodiment of this application, drying a suspension containing modified bentonite to obtain modified bentonite comprises:

[0017] The suspension containing modified bentonite was dewatered using a plate and frame filter press. The filter residue was washed with deionized water at least twice and then dewatered separately to obtain the dewatered product.

[0018] The dehydrated product was dried at 100–120°C to obtain modified bentonite.

[0019] According to one embodiment of this application, the particle size of the organic cationic modified bentonite powder is 300-500 mesh.

[0020] According to one embodiment of this application, the modified bentonite is mixed with an amino acid salt modifier and then subjected to dry modification, including:

[0021] Modified bentonite was mixed with an amino acid salt modifier and dry-modified at a temperature of 80–110℃.

[0022] According to one embodiment of this application, the bentonite powder has a mass content of 3% to 7% in the mixed solution.

[0023] Secondly, embodiments of this application provide a composite bentonite, which is prepared by the method described in the first aspect.

[0024] This application has at least the following beneficial effects:

[0025] According to the embodiments of this application, the composite modified bentonite utilizes bentonite and an organic cationic modifier. Through intercalation modification, the organic cationic modifier is inserted between the bentonite crystal structures via ion exchange to form organic cationic bentonite, giving it a certain moisturizing effect. Then, the surface of the bentonite is modified by an amino acid salt modifier to form a composite modified bentonite. This allows the composite modified bentonite to not only have a good moisturizing effect but also to adsorb oil and control oil, thus achieving the purpose of oil control without drying out the bentonite. Detailed Implementation

[0026] The embodiments of this application will be described in further detail below with reference to the examples. The detailed description of the following embodiments is used to illustrate the principles of this application, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0027] In the description of this application, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationships, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the allowable tolerance range. "Parallel" is not parallel in the strict sense, but within the allowable tolerance range.

[0028] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application depending on the specific circumstances.

[0029] Preparation method of composite bentonite

[0030] In a first aspect, embodiments of this application propose a method for preparing composite bentonite, comprising:

[0031] Step 101: Provide a mixed solution comprising bentonite powder, an organic cationic modifier, and water;

[0032] Step 102: The mixed solution is reacted at a temperature of 60-80°C to obtain a suspension containing modified bentonite.

[0033] Step 103: The suspension containing modified bentonite is dried to obtain modified bentonite, wherein the water content of the modified bentonite is less than 1.5%.

[0034] Step 104: The modified bentonite is pulverized to obtain organic cationic modified bentonite powder;

[0035] Step 105: Mix the organic cationic modified bentonite powder with an amino acid salt modifier and perform dry modification to obtain composite modified bentonite.

[0036] According to the preparation method of this application embodiment, bentonite is intercalated and modified using an organic cationic modifier. The organic cationic modifier is inserted between the bentonite crystal structures through ion exchange to form organic cationic bentonite, which has a certain moisturizing effect. The surface of bentonite is modified by an amino acid salt modifier to form a composite modified bentonite, which has a good moisturizing effect and can adsorb oil to achieve oil control. The organic cationic modifier and the amino acid salt modifier work together to modify bentonite, achieving the effect of oil control without drying out the composite modified bentonite.

[0037] According to embodiments of this application, bentonite can be sodium-based bentonite (alkaline clay), calcium-based bentonite (alkaline earth clay), or natural bleaching clay (acidic clay or acidic white clay), wherein calcium-based bentonite includes calcium-sodium-based and calcium-magnesium-based. Studies have found that sodium-based bentonite reacts better with organic cationic modifiers and amino acid salt modifiers than calcium-based bentonite, thus exhibiting a more effective moisturizing and oil-controlling effect compared to calcium-based bentonite.

[0038] In some embodiments, prior to step 101, the method further includes: preparing an aqueous suspension solution by air jet milling of the bentonite raw material. In some embodiments, to further reduce the influence of calcium and magnesium ions in the bentonite raw material, a saturated Na2CO3 solution is added to the aqueous suspension solution to adjust the overall pH of the suspension to 7.5–8.5.

[0039] In some optional embodiments, step 101, the organic cationic modifier includes one or more of the following: hydroxypropyltrimethylammonium chloride hyaluronic acid, locust bean gum hydroxypropyltrimethylammonium chloride, aralia elata hydroxypropyltrimethylammonium chloride, starch hydroxypropyltrimethylammonium chloride, panthenol-hydroxypropylstearyl dimethylammonium chloride, and dextran-hydroxypropyltrimethylammonium chloride.

[0040] In the embodiments of this application, the organic cationic modifier can be an organic cationic modifier with moisturizing properties. Modification using such an organic cationic modifier can improve the moisturizing effect of bentonite. Furthermore, the organic cationic modifier can form a hydrophilic film inside the bentonite particles, effectively retaining water molecules and enhancing the long-lasting moisturizing effect of the bentonite.

[0041] As an example, the organic cationic modification process includes the following chemical reaction processes:

[0042] Ca-Benton+Na + →Na-Benton + Ca 2+

[0043] Na-Benton+R-NH4 + ·Cl - →Benton·R-NH4 + +NaCl

[0044] In the formula, Benton is bentonite, and R-NH4 + ·Cl - It is an organic cationic modifier.

[0045] In some alternative embodiments, in step 101, the mass ratio of bentonite powder to organic cationic modifier is 1:(0.8 to 1.2).

[0046] In this embodiment, the mass ratio of bentonite powder to organic cationic modifier is within the above-mentioned range. This allows a moisturizing film to be formed inside the bentonite, effectively slowing down the evaporation rate of water and thus improving the water retention performance of the bentonite. It also enables the formation of a more uniform and stable porous structure, which is beneficial for improving air permeability and water retention. As an example, the mass ratio of bentonite powder to organic cationic modifier can be any ratio or range thereof from 1:0.8, 1:0.9, 1:1.0, 1:1.1, to 1:1.2.

[0047] In some alternative embodiments, in step 101, the bentonite powder has a mass content of 3% to 7% in the mixed solution.

[0048] In this embodiment, the mass content of bentonite powder in the mixed solution is within the above-mentioned range, which ensures that the bentonite and the modifier are fully mixed, promoting the reaction. An appropriate amount of bentonite can provide sufficient reaction surface area and adsorption sites, which is beneficial to the interaction between the modifier and the bentonite particles, thereby improving the modification effect. As an example, the mass content of bentonite powder in the mixed solution can be any value or a range thereof of 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, and 7%.

[0049] In some optional embodiments, step 102 involves reacting the mixed solution at a temperature of 60–80°C to obtain a suspension containing modified bentonite. In some embodiments, the reaction time is 3–6 hours.

[0050] In this embodiment, the organic cationic modifier and bentonite can react at the above-mentioned temperature, which is beneficial to improving the moisture retention properties of bentonite. For example, the temperature can be 65°C, 70°C, 72°C, 75°C, or 78°C.

[0051] In some optional embodiments, step 103, drying the suspension containing modified bentonite to obtain modified bentonite, includes:

[0052] The suspension containing modified bentonite was dewatered using a plate and frame filter press. The filter residue was washed with deionized water at least twice and then dewatered separately to obtain the dewatered product.

[0053] The dehydrated product was dried at 100–120°C to obtain modified bentonite.

[0054] In some alternative embodiments, in step 103, the particle size of the organic cationic modified bentonite powder is 300-500 mesh.

[0055] In this embodiment, controlling the particle size of the organic cationic modified bentonite powder within the aforementioned range is beneficial for subsequent surface amino modification, thereby improving the bentonite's oil adsorption effect and achieving the goal of oil control. As an example, the particle size of the organic cationic modified bentonite powder can be any value among 300 mesh, 400 mesh, and 500 mesh. A particle size of 300 mesh can be understood as the organic cationic modified bentonite powder passing through a 300-mesh sieve.

[0056] In some embodiments, step 104, pulverizing the modified bentonite, can be performed using an air jet mill.

[0057] In some embodiments, step 105, dry modification can be performed by feeding the organic cationic modified bentonite powder into an SLG type continuous powder surface modification machine for dry modification.

[0058] In some alternative embodiments, step 105, the amino acid salt modifier includes one or more of disodium stearoyl glutamate, disodium lauroyl glutamate, disodium cocoyl glutamate, sodium lauroyl glutamate, sodium stearoyl glutamate, and sodium cocoyl glutamate.

[0059] In this embodiment, the aforementioned amino acid salt modifiers can impart amino functional groups to the surface of bentonite, thereby enhancing its adsorption capacity. In cosmetics, this modification can strengthen bentonite's adsorption capacity for oils, dirt, and skin surfaces, helping to thoroughly cleanse the skin, absorb excess oil, reduce shine, and keep the skin refreshed. Furthermore, it can regulate sebum secretion.

[0060] Furthermore, the introduction of amino functional groups can enhance the dispersibility and stability of bentonite in cosmetics. In products such as emulsions and foundations, bentonite acts as a dispersant and stabilizer, helping to evenly disperse other ingredients and maintain product stability. The introduction of amino functional groups also enhances the adhesion of bentonite. In makeup products such as foundations and pressed powders, bentonite helps the product adhere better to the skin surface, making makeup last longer.

[0061] In some alternative embodiments, in step 105, the mass ratio of the amino acid salt modifier to the organic cationic modified bentonite powder is (1-3):100.

[0062] In this embodiment, the mass ratio of amino acid salt modifier to organic cationic modified bentonite powder is within the above-mentioned range. Different mass ratios of amino acid modifier react with bentonite to adjust the chemical properties of the bentonite surface, affecting its adsorption capacity for oils and dirt. An appropriate amount of modifier can enhance the adsorption capacity of bentonite, helping to thoroughly cleanse the skin, reduce pore blockage, and improve skin texture. An appropriate amount of modifier can make the bentonite surface gentler, reducing skin irritation and discomfort, and improving the skin adaptability of cosmetics. As an example, the mass ratio of amino acid salt modifier to organic cationic modified bentonite powder can be any ratio or range thereof from 1:100, 1.5:100, 1.8:100, 2:100, 2.5:100, 2.8:100, and 3:100.

[0063] In some alternative embodiments, step 105, mixing the modified bentonite with an amino acid salt modifier and performing dry modification, includes:

[0064] Modified bentonite was mixed with an amino acid salt modifier and dry-modified at a temperature of 80–110℃.

[0065] In this embodiment, the modified bentonite and the amino acid salt modifier can react at the above-mentioned temperature, which is beneficial to improving the oil control performance of the bentonite. For example, the temperature can be 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, or 110℃.

[0066] Composite bentonite

[0067] Secondly, embodiments of this application provide a composite bentonite, which is prepared by the method described in the first aspect.

[0068] In this embodiment, the composite bentonite can be a type of powder material that can be used in cosmetics. This composite bentonite powder material contains organic substances with a certain moisturizing effect within its particles, and its surface is modified with amino groups, achieving both moisturizing and oil-absorbing effects. Therefore, this composite modified bentonite possesses oil-controlling and non-drying properties. The composite bentonite obtained in this application is suitable for base makeup products, such as oil-controlling long-lasting foundations and cushion foundations. 。

[0069] Example

[0070] The following embodiments describe the disclosure of this application in more detail. These embodiments are merely illustrative, as various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of this application. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on mass, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0071] Example 1

[0072] This embodiment describes a method for preparing composite modified bentonite, comprising:

[0073] 1. Prepare an aqueous suspension of bentonite:

[0074] First, the selected sodium-based bentonite is pulverized using an air jet mill, then a 5% suspension is prepared with deionized water, and a saturated Na2CO3 solution is added to adjust the pH to 8.0. The mixture is then stirred thoroughly.

[0075] 2. Organic cationic modification:

[0076] The bentonite suspension was heated to 70°C, and under stirring conditions, hydroxypropyltrimethylammonium chloride hyaluronic acid with a weight ratio of 1:1 to bentonite was added, and the mixture was stirred continuously for 4 hours.

[0077] 3. Dehydration and drying: After the reaction is completed, the filter residue is dehydrated using a plate and frame filter press. The filter residue is washed twice with deionized water and then dehydrated again. It is then dried at 110°C until the moisture content is 1.2%.

[0078] 4. The dried organic cationic modified bentonite is pulverized by airflow in a pulverizer until the particles reach 300-500 mesh.

[0079] 5. The pulverized organic cationic modified bentonite is put into an SLG type continuous powder surface modifier, the modification temperature is controlled at 100℃, and disodium stearoyl glutamate is added for dry modification. The amount of disodium stearoyl glutamate is 2% of the mass of the organic cationic modified bentonite.

[0080] 6. After modification, the composite modified bentonite is obtained, denoted as Benton-B1.

[0081] Example 2

[0082] This embodiment describes a method for preparing composite modified bentonite, using the same method as in Example 1, with the difference being:

[0083] Step 2: Add starch hydroxypropyltrimethylammonium chloride at a weight ratio of 1:0.9 with bentonite, and stir continuously for 3.5 hours.

[0084] After modification with organic cations and amino acids using the same method as in Example 1, a composite modified bentonite was obtained, denoted as Benton-B2.

[0085] Example 3

[0086] This embodiment is used to illustrate the composite modified bentonite and its preparation method provided by the present invention.

[0087] Modified bentonite was prepared using the same method as in Example 1, except that:

[0088] In step 1, the pH of the suspension was adjusted to 7.5 using a saturated Na2CO3 solution. In step 2, hydroxypropyltrimethylammonium chloride hyaluronic acid with a bentonite weight ratio of 1:0.8 was added, and the mixture was stirred continuously for 5 hours.

[0089] After modification with organic cations and amino acids using the same method as in Example 1, a composite modified bentonite was obtained, denoted as Benton-B3.

[0090] Example 4

[0091] This embodiment provides a method for preparing composite modified bentonite, using the same method as in Example 1, except that:

[0092] In step 5, sodium lauroyl glutamate is added for dry modification. The amount of sodium lauroyl glutamate is 1.5% of the mass of the organic cationic modified bentonite.

[0093] After modification with organic cations and amino acids using the same method as in Example 1, a composite modified bentonite was obtained, denoted as Benton-B4.

[0094] Example 5

[0095] This embodiment describes a method for preparing composite modified bentonite, using the same method as in Example 1, with the difference being:

[0096] In step 2, the bentonite suspension is heated to 75°C, and under stirring conditions, hydroxypropyltrimethylammonium chloride hyaluronic acid with a weight ratio of 1:1.1 to bentonite is added, and the mixture is stirred continuously for 5.5 hours.

[0097] In step 5, the amino acid modifier is selected as sodium cocoyl glutamate, and the amount used is 3% of the mass of the organic cationic modified bentonite, and the modification temperature is 80℃.

[0098] After modification with organic cations and amino acids using the same method as in Example 1, a composite modified bentonite was obtained, denoted as Benton-B5.

[0099] Example 6

[0100] The preparation method in this embodiment differs from that in Example 1 in that: calcium-based bentonite is used as the raw material, and the pH is directly adjusted to 8.0 without sodium treatment, followed by thorough mixing; subsequent organic cation modification and other operations are performed. The resulting composite modified bentonite is designated Benton-B6.

[0101] Example 7

[0102] The preparation method in this embodiment differs from that in Example 1 in that the mass ratio of the amino acid salt modifier to the organic cationic modified bentonite powder is 0.5:100. The resulting composite modified bentonite is designated Benton-B7.

[0103] Example 8

[0104] The preparation method of this embodiment differs from that of Example 1 in that the mass ratio of the amino acid salt modifier to the organic cationic modified bentonite powder is 10:100. The resulting composite modified bentonite is denoted as Benton-B8.

[0105] Example 9

[0106] The preparation method of this embodiment differs from that of Example 1 in that the mass ratio of bentonite powder to organic cationic modifier is 1:2. A composite modified bentonite, denoted as Benton-B9, is obtained.

[0107] Performance testing

[0108] 1. Oil absorption value test

[0109] Test method: Accurately weigh 100g of the test substance, namely bentonite, used in the examples and comparative examples (i.e., the untreated sodium-based bentonite raw material in the examples), and slowly add simulated sebum oil (sebum oil: squalene: oleic acid: caprylic / capric triglyceride = 1:1:1) dropwise while stirring until a clumping mass without dry powder is formed. Record the amount of simulated sebum oil added, which is recorded as the oil absorption value.

[0110] The oil absorption values ​​of different test substances are shown in Table 1:

[0111] Table 1: Oil Absorption Value Test Results

[0112] Test object Oil absorption value (g / 100g) Sodium bentonite 45.01 Benton-B1 70.21 Benton-B2 68.95 Benton-B3 69.35 Benton-B4 71.24 Benton-B5 70.86 Benton-B6 60.84 Benton-B7 68.37 Benton-B8 71.55 Benton-B9 70.85

[0113] Comparing the oil absorption values ​​of Benton-B1 to B9 with those of untreated sodium-based bentonite and cationic modified bentonite, the composite modified bentonite provided by this invention has a moderate oil absorption value, which is significantly higher than that of untreated sodium-based bentonite.

[0114] 2. Contact Angle Test

[0115] Test method: The test material (composite modified bentonite) of the examples and comparative examples was uniformly coated onto a glass slide, and the slide was air-dried. The contact angle was measured using a contact angle meter via the static drop method. The smaller the contact angle, the stronger the hydrophilicity, and vice versa.

[0116] The contact angle test results for different test materials are shown in Table 2:

[0117] Table 2: Contact Angle Test Results

[0118] Test object Contact angle Sodium bentonite 24.5° Benton-B1 35.3° Benton-B2 31.5° Benton-B3 32.3° Benton-B4 33.2° Benton-B5 32.8° Benton-B6 30.3° Benton-B7 34.5° Benton-B8 33.5° Benton-B9 32.9°

[0119] Comparing the contact angle test results of Benton-B1 to B9 with untreated sodium-based bentonite and cationic modified bentonite, the composite modified bentonite provided by the present invention has an increased contact angle compared with untreated sodium-based bentonite.

[0120] 3. Oil control and moisturizing rate test of long-lasting foundation:

[0121] The oil and moisture content of the long-lasting foundation were measured immediately after application and 6 hours later using a CK skin analyzer. The calculation method was to divide the test data after 6 hours by the test data before applying the foundation. Immediate oil and moisture data were measured 1 hour after cleansing with a facial cleanser.

[0122] The calculation method for oil control rate is: (Oil content after 6 hours - Oil content measured immediately) / Oil content measured immediately.

[0123] The calculation method for skin hydration rate is: (Skin moisture after 6 hours - Skin moisture measured immediately) / Skin moisture measured immediately.

[0124] The basic formulas of the tested long-lasting foundations are shown in Table 3:

[0125] Table 3: Long-lasting foundation

[0126]

[0127]

[0128] The selection of bentonite is shown in Table 4.

[0129] Table 4 Different formulations of the same modified bentonite

[0130] formula Various bentonites Formula 1 Sodium-based bentonite raw materials Formula 2 Benton-B1 Formula 3 Benton-B2 Formula 4 Benton-B3 Formula 5 Benton-B4 Formula 6 Benton-B5 Formula 7 Benton-B6 Formula 8 Benton-B7 Formula 9 Benton-B8 Formula 10 Benton-B9

[0131] The oil control and moisturizing rates of the long-lasting foundations (formulas 1 to 11) are shown in Table 5.

[0132] Table 5 shows the oil control and moisturizing rates of long-lasting foundations with different modified bentonite formulas.

[0133]

[0134]

[0135] Table 5 shows that the composite modified bentonite obtained from formulas 2-6 has good oil control and moisturizing effects. The makeup-holding foundation prepared with it also has good moisturizing effects, with the characteristics of oil control without drying. Compared with formulas 2-6, formula 7 has a lower degree of final modification due to the lack of sodium modification of the composite modified bentonite, which limits the good oil control and moisturizing effects of the composite modified bentonite. Compared with formulas 3-7, even with an increase in the amount of modifier, the good oil control and moisturizing effects of the composite modified bentonite in formulas 9-10 are not increased. The reason may be that the modifier cannot be adsorbed excessively in the middle layer and surface of the bentonite, and its degree of modification is limited. Excessive modifier cannot produce an additive effect.

[0136] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for preparing composite bentonite, characterized in that, include: Provides a mixed solution comprising bentonite powder, organic cationic modifier, and water; The mixed solution was reacted at a temperature of 60-80°C to obtain a suspension containing modified bentonite. The suspension containing modified bentonite is dried to obtain modified bentonite, wherein the water content of the modified bentonite is less than 1.5%; The modified bentonite was pulverized to obtain organic cationic modified bentonite powder. The organic cationic modified bentonite powder was mixed with an amino acid salt modifier and then dry modified to obtain composite modified bentonite. The organic cationic modifier includes at least one of hydroxypropyltrimethylammonium chloride hyaluronic acid and starch hydroxypropyltrimethylammonium chloride, and the mass ratio of the bentonite powder to the organic cationic modifier is 1:(0.8-1.2). The amino acid salt modifier includes one or more of disodium stearoyl glutamate, disodium lauroyl glutamate, disodium cocoyl glutamate, sodium lauroyl glutamate, sodium stearoyl glutamate, and sodium cocoyl glutamate, and the mass ratio of the amino acid salt modifier to the organic cationic modified bentonite powder is (1-3):

100. The bentonite is sodium-based bentonite.

2. The preparation method according to claim 1, characterized in that, The step of drying the suspension containing modified bentonite to obtain modified bentonite includes: The suspension containing modified bentonite was dewatered using a plate and frame filter press. The filter residue was washed with deionized water at least twice and then dewatered separately to obtain the dewatered product. The dehydrated product was dried at 100–120°C to obtain modified bentonite.

3. The preparation method according to claim 1, characterized in that, The particle size of the organic cationic modified bentonite powder is 300-500 mesh.

4. The preparation method according to claim 1, characterized in that, The step of mixing the modified bentonite with an amino acid salt modifier and performing dry modification includes: The modified bentonite was mixed with an amino acid salt modifier and subjected to dry modification at a temperature of 80–110°C.

5. The preparation method according to claim 1, characterized in that, The bentonite powder has a mass content of 3% to 7% in the mixed solution.

6. A composite bentonite, prepared by any one of claims 1 to 5.

Images