Self-dispersing color lake for water-based cosmetic material and preparation process of self-dispersing color lake

Abstract

The invention discloses a self-dispersing color lake for a water-based cosmetic material and a preparation process of the self-dispersing color lake. The preparation process comprises the following steps: firstly, carrying out hydrophobic treatment on the surface of the color lake by using a hydrophobic treatment agent to prepare a hydrophobic color lake; then, the lake subjected to hydrophobic treatment and the amphiphilic copolymer are subjected to self-assembly in water, the surface of the lake is subjected to hydrophilic treatment, in the process, a hydrophobic chain segment in the polymer can be spontaneously combined with a hydrophobic group on the surface of the lake, and then a hydrophilic chain segment is spontaneously exposed to the surface of the lake. And finally, preparing the lake capable of self-dispersing in water through a freeze-drying process. According to the method, the double surface treatment technology of the lake is adopted, two plating layers with different properties are constructed on the surface of the lake, the inner hydrophobic layer prevents the lake from making contact with water, the stability of the lake in water is improved, meanwhile, the outermost hydrophilic layer promotes dispersity of the lake in water, and rapid self-dispersion of the lake in water is achieved through the freeze-drying technology.

Description

Technical Field

[0001] This invention relates to the field of cosmetic pigment technology, specifically to a self-dispersing lake for water-based cosmetics and its preparation process. Background Technology

[0002] Organic pigments can be broadly classified into two types: lake pigments and pigment pigments. Lake pigments refer to water-soluble pigments that have been converted into water-insoluble microparticles by metal salts or other precipitating agents. Compared to water-soluble pigments, lakes have bright colors, good dispersibility and hiding power, and are stable within a pH range of 3.5-9.5. However, outside this range, the pigment and aluminum bonds will be broken, and the lake will disintegrate and separate. In addition, lakes have the advantages of bright colors, a wide color gamut, and high transparency, and are widely used in products that require bright colors, such as eyeliner and nail polish. Especially when formulating highly saturated bright colors, organic lakes have advantages that pigment powder cannot replace.

[0003] Currently, lakes are formed by complexing organic pigments containing sulfonic acid or carboxylic acid groups with aluminum, calcium, or other ions, followed by drying to form a relatively dense lake structure. These lakes are primarily used in oil-based cosmetic systems. However, due to the strong polarity of water, which can combine with metal ions and organic matter, the complexed lakes in aqueous systems undergo a process of dissolution, dissociation, and recombination. Simultaneously, the metal ions dissolved from the lake form complex complexes with polymers in the water-based cosmetic system, leading to lake swelling (similar to a gel structure), increased viscosity, flocculent formation, and the precipitation of solids. This limits the use of lakes in water-based cosmetic products, and they are more often applied to oil-based and wax-based products after surface hydrophobic treatment.

[0004] In the prior art, for example, patent CN119955326A discloses a method for preparing permanent red pigment for acid and alkali resistant coatings. After diazotization of a 2B acid derivative, it is coupled with 2-hydroxy-3-naphthoic acid, and then a calcium chloride aqueous solution is added for lake formation to obtain pigment particles. Finally, silica is coated onto the surface of the pigment particles, and a fluorosilane coupling agent is used to hydrophobically treat the silica coating layer to obtain the permanent red pigment for acid and alkali resistant coatings. While maintaining the excellent properties of the original Pigment Red 48:2, this method further enhances the pigment's acid and alkali resistance and environmental stability, significantly improving its application performance. However, the above treatment only performs a single hydrophobic treatment on the surface of the lake, reducing the lake's hydrophilicity and making it difficult to disperse in aqueous solutions. It is only suitable for oil-based systems and cannot meet the "instant dissolution and dispersion" requirement of water-based cosmetics.

[0005] Patent CN119875391A discloses a water-resistant and boil-resistant light-resistant lotus lake and its preparation method. The light-resistant lotus lake is used as the core material, and a composite wall material is prepared using epoxy resin, diisocyanate, and cage-type polysilsesquioxane (POSS). Microcapsule lakes are then encapsulated to create composite wall material microcapsules, significantly enhancing the water resistance and boil-resistance of the prepared lotus lake. However, the microcapsule encapsulation process is complex, requiring precise control of the polymerization reaction conditions (temperature, pH, emulsification rate, etc.) of the epoxy resin, diisocyanate, and (POSS). Furthermore, its high-temperature stability is insufficient; the glass transition temperature of the organic wall material (epoxy resin) is much lower than the sterilization temperature for cosmetics, leading to capsule wall rupture after boiling. Additionally, the difference in thermal expansion coefficients between the rigid POSS skeleton and the resin causes high-temperature interface delamination, resulting in a solid substance. Summary of the Invention

[0006] To address the problem of lakes swelling in water (resulting in a gel-like structure), increasing viscosity, forming flocculent substances, and precipitating solids, this invention provides a self-dispersible lake for water-based cosmetics and its preparation process. It employs a dual surface treatment technology, constructing two protective layers with different properties on the surface of the lake. The hydrophobic layer prevents the lake from contacting water, improving its stability in water, while the outermost hydrophilic layer promotes the dispersibility of the lake in water.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A first aspect of the present invention provides a process for preparing a self-dispersing lake for aqueous cosmetics, comprising the following steps:

[0009] S1. The surface of the lake is hydrophobically treated with a hydrophobic agent to obtain a hydrophobic lake;

[0010] S2. The hydrophobic lake obtained in step S1 is self-assembled with the amphiphilic copolymer in water to hydrophilize the surface of the lake.

[0011] S3. The lake treated in step S2 is then thoroughly dried using a freeze-drying process to obtain the finished product.

[0012] Furthermore, in step S1, the hydrophobic treatment agent is triethoxyoctylsilane or polyhydroxystearic acid.

[0013] Hydrophobic treatment agents include one or more of triethoxyoctylsilane, polyhydroxystearic acid, titanate, and polymethoxysiloxane.

[0014] Preferably, the hydrophobic treatment agent is a mixed solution of triethoxyoctylsilane and polyhydroxystearic acid in a mass ratio of 10:1 to 3:1. More preferably, the hydrophobic treatment agent is a mixed solution of triethoxyoctylsilane and polyhydroxystearic acid in a mass ratio of 7:1 to 4:1.

[0015] Further, in step S1, 4-10 parts by weight of hydrophobic treatment agent and 1-3 parts by weight of water are first thoroughly stirred and mixed to obtain a mixed solution. Then, the above mixed solution is dropped onto 90-100 parts by weight of starch pigment while being stirred at high speed. Finally, the thoroughly mixed powder is placed in a drying oven for drying to obtain a hydrophobic lake.

[0016] Furthermore, the drying temperature is 100-150℃, and the drying time is 2-5 hours. Lower drying temperatures are not conducive to the dehydration condensation reaction of the hydrophobic agent, while higher drying temperatures will cause the hydrophobic agent to volatilize and deteriorate, which is not conducive to the construction of the hydrophobic film.

[0017] Furthermore, in step S2, the amphiphilic copolymer is hydrogenated castor oil-polyethylene glycol or polyhydroxystearic acid-polyethylene glycol.

[0018] Further, in step S2, 20-30 parts by weight of hydrophobic starch and 2-6 parts by weight of amphiphilic copolymer are first thoroughly stirred and mixed to form a viscous paste. Then, 61-70 parts by weight of water are slowly added to the paste while stirring until the paste is fully dispersed to form a uniform lake dispersion. Then, stirring is continued for more than 1 hour. Finally, the lake dispersion is filtered to recover the starch.

[0019] In this step, the process of forming a paste is more conducive to the amphiphilic polymer encapsulating the color powder. At the same time, the slow addition of water and continuous stirring for more than 1 hour give the self-assembly process a longer assembly time (> relaxation time), thereby promoting the formation of a uniform film layer of amphiphilic polymer on the powder surface.

[0020] Furthermore, the recovered starch pigment is freeze-dried, specifically by pre-freezing at -40℃ for 4 hours, followed by vacuum drying at -40 to -20℃ for 8 to 24 hours. Compared to traditional drying processes, this freeze-drying process effectively maintains the structure of the powder in the solution and effectively inhibits the entanglement of polymer chains on the surface of the pigment during the drying process, thereby endowing the pigment with excellent self-dispersibility in water.

[0021] Furthermore, the lakes include, but are not limited to, CI 42090 aluminum lake, CI 42090 calcium lake, CI 42090 barium lake, CI 15850 aluminum lake, CI 15850 calcium lake, CI 15850 barium lake, CI 16035 aluminum lake, CI 16035 calcium lake, CI 16035 barium lake, etc.

[0022] The above technical solution is adopted:

[0023] This invention provides a new surface treatment technology for lakes, which can endow pigments with excellent hydrophilicity while solving the problems of poor stability of lakes such as swelling, gelation, and solid formation in water.

[0024] This invention first uses hydrophobic agents such as triethoxyoctylsilane and polyhydroxystearic acid to hydrophobize the surface of a lake, preparing a hydrophobic lake. Then, the hydrophobically treated lake and amphiphilic copolymers such as hydrogenated castor oil-polyethylene glycol and polyhydroxystearic acid-polyethylene glycol undergo self-assembly in water to hydrophilize the lake surface. During this process, the hydrophobic segments in the polymer spontaneously combine with the hydrophobic groups on the lake surface, thus exposing the hydrophilic segments. Finally, a self-dispersible lake in water is prepared through freeze-drying. This invention employs a dual surface treatment technology for the lake, which constructs two coatings with different properties on the lake surface. The inner hydrophobic layer prevents the lake from contacting water, improving its stability in water, while the outermost hydrophilic layer promotes the dispersion of the lake in water. The freeze-drying process achieves rapid self-dispersion of the lake in water (see details). Figure 1 ).

[0025] This invention constructs a double coating on the surface of a lake using a dual surface treatment technology. The inner hydrophobic layer inhibits water penetration, solving the problem of lake instability, while the outer hydrophilic layer promotes the dispersion of the lake in water.

[0026] In a second aspect, the present invention provides a self-dispersing lake for use in water-based cosmetics, which is prepared by the above-described preparation process.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] This invention first uses hydrophobic agents such as triethoxyoctylsilane and polyhydroxystearic acid to hydrophobize the surface of a lake, thus preparing a hydrophobic lake. This method utilizes the dehydration condensation reaction of triethoxyoctylsilane and polyhydroxystearic acid on the lake surface to impart a structurally stable hydrophobic coating to the lake.

[0029] Subsequently, the hydrophobically treated lake and amphiphilic copolymers such as hydrogenated castor oil-polyethylene glycol and polyhydroxystearic acid-polyethylene glycol were self-assembled in water to hydrophilize the lake surface. During this process, the hydrophobic segments in the polymer spontaneously combine with the hydrophobic groups on the lake surface, thereby exposing the hydrophilic segments spontaneously on the lake surface. Finally, a self-dispersible lake in water was prepared by freeze-drying.

[0030] This invention employs a dual surface treatment technology for lakes, which constructs two coatings with different properties on the surface of the lake. The inner hydrophobic layer prevents the lake from contacting water, improving its stability in water, while the outermost hydrophilic layer promotes the dispersion of the lake in water. The freeze-drying process enables the lake to rapidly self-disperse in water. Attached Figure Description

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0032] Figure 1 This is a schematic diagram illustrating the preparation process of the self-dispersing lake in Example 1;

[0033] Figure 2 Photographs showing the dispersion of the hydrophobically treated blue lake in Comparative Example 2 and the dual-treated blue lake in Example 1 in water;

[0034] Figure 3 The image shows an inverted photograph of the untreated blue lake in Comparative Example 1 and the double-treated blue lake in Example 1 after they were dispersed in water and left to stand at 50°C for 24 hours. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1

[0037] A process for preparing a self-dispersing lake for use in water-based cosmetics, such as... Figure 1 As shown, it includes the following steps:

[0038] S1. Hydrophobic surface treatment of lake:

[0039] First, 8 parts by weight of hydrophobic treatment agent (including 6 parts by weight of triethoxyoctylsilane and 2 parts by weight of polyhydroxystearic acid) and 2 parts by weight of water are thoroughly mixed to obtain a mixed solution. Then, the above mixed solution is dropped onto 90 parts by weight of pigment starch (CI 42090 aluminum lake) and simultaneously subjected to high-speed stirring (2000 rpm for 10 seconds). The stirring is repeated three times. Finally, the thoroughly mixed powder is placed in a drying oven for drying at 120°C for 2 hours to obtain a hydrophobic lake.

[0040] S2, Hydrophilic surface treatment of lake:

[0041] First, 24 parts by weight of hydrophobic starch pigment and 5 parts by weight of amphiphilic copolymer (hydrogenated castor oil-polyethylene glycol) are thoroughly mixed to form a viscous paste. Then, 61 parts by weight of water are slowly added to the paste while stirring until the paste is fully dispersed to form a uniform lake dispersion. Then, stirring is continued for more than 1 hour. Finally, the lake dispersion is filtered to recover the starch pigment.

[0042] S3, freeze-drying treatment:

[0043] The lake treated in step S2 is then thoroughly dried using a freeze-drying process (pre-freezing at -40℃ for 4 hours → vacuum drying at -40℃ for 8 hours) to obtain the finished product.

[0044] Example 2

[0045] A process for preparing a self-dispersing lake for use in water-based cosmetics, such as... Figure 1 As shown, it includes the following steps:

[0046] S1. Hydrophobic surface treatment of lake:

[0047] First, 4 parts by weight of hydrophobic treatment agent (including 3.2 parts by weight of triethoxyoctylsilane and 0.8 parts by weight of polyhydroxystearic acid) and 1 part by weight of water are thoroughly mixed to obtain a mixed solution. Then, the above mixed solution is dropped onto 95 parts by weight of pigment starch (CI 42090 aluminum-based lake) and simultaneously subjected to high-speed stirring (2000 rpm for 10 s). The stirring is repeated three times. Finally, the thoroughly mixed powder is placed in a drying oven for drying at 120℃ for 2 hours to obtain a hydrophobic lake.

[0048] S2, Hydrophilic surface treatment of lake:

[0049] First, 20 parts by weight of hydrophobic starch pigment and 4 parts by weight of amphiphilic copolymer (hydrogenated castor oil-polyethylene glycol) are thoroughly mixed to form a viscous paste. Then, 64 parts by weight of water are slowly added to the paste while stirring until the paste is fully dispersed to form a uniform lake dispersion. Then, stirring is continued for more than 1 hour. Finally, the lake dispersion is filtered to recover the starch pigment.

[0050] S3, freeze-drying treatment:

[0051] The lake treated in step S2 is then thoroughly dried using a freeze-drying process (pre-freezing at -40℃ for 4 hours → vacuum drying at -40℃ for 8 hours) to obtain the finished product.

[0052] Example 3

[0053] A process for preparing a self-dispersing lake for use in water-based cosmetics, such as... Figure 1 As shown, it includes the following steps:

[0054] S1. Hydrophobic surface treatment of lake:

[0055] First, 10 parts by weight of hydrophobic treatment agent (including 8.75 parts by weight of triethoxyoctylsilane and 1.25 parts by weight of polyhydroxystearic acid) and 3 parts by weight of water are thoroughly mixed to obtain a mixed solution. Then, the above mixed solution is dropped onto 100 parts by weight of pigment starch (CI 42090 aluminum-based lake) and simultaneously subjected to high-speed stirring (2000 rpm for 10 seconds). The stirring is repeated three times. Finally, the thoroughly mixed powder is placed in a drying oven for drying at 120°C for 2 hours to obtain a hydrophobic lake.

[0056] S2, Hydrophilic surface treatment of lake:

[0057] First, 25 parts by weight of hydrophobic starch pigment and 5 parts by weight of amphiphilic copolymer (hydrogenated castor oil-polyethylene glycol) are thoroughly mixed to form a viscous paste. Then, 70 parts by weight of water are slowly added to the paste while stirring until the paste is fully dispersed to form a uniform lake dispersion. Then, stirring is continued for more than 1 hour. Finally, the lake dispersion is filtered to recover the starch pigment.

[0058] S3, freeze-drying treatment:

[0059] The lake treated in step S2 is then thoroughly dried using a freeze-drying process (pre-freezing at -40℃ for 4 hours → vacuum drying at -20℃ for 24 hours) to obtain the finished product.

[0060] Example 4

[0061] A process for preparing a self-dispersing lake for use in water-based cosmetics, such as... Figure 1As shown, it includes the following steps:

[0062] S1. Hydrophobic surface treatment of lake:

[0063] First, 5 parts by weight of hydrophobic treatment agent (including 4.5 parts by weight of triethoxyoctylsilane and 0.5 parts by weight of polyhydroxystearic acid) and 2 parts by weight of water are thoroughly mixed to obtain a mixed solution. Then, the above mixed solution is dropped onto 93 parts by weight of pigment starch (CI 15850 calcium lake) and simultaneously subjected to high-speed stirring (2000 rpm for 10 seconds). The stirring is repeated three times. Finally, the thoroughly mixed powder is placed in a drying oven for drying at 120°C for 2 hours to obtain a hydrophobic lake.

[0064] S2, Hydrophilic surface treatment of lake:

[0065] First, 30 parts by weight of hydrophobic starch pigment and 2 parts by weight of amphiphilic copolymer (hydrogenated castor oil-polyethylene glycol) are thoroughly mixed to form a viscous paste. Then, 68 parts by weight of water are slowly added to the paste while stirring until the paste is fully dispersed to form a uniform lake dispersion. Then, stirring is continued for more than 1 hour. Finally, the lake dispersion is filtered to recover the starch pigment.

[0066] S3, freeze-drying treatment:

[0067] The lake treated in step S2 is then thoroughly dried using a freeze-drying process (pre-freezing at -40℃ for 4 hours → vacuum drying at -20℃ for 24 hours) to obtain the finished product.

[0068] Example 5

[0069] A process for preparing a self-dispersing lake for use in water-based cosmetics, such as... Figure 1 As shown, it includes the following steps:

[0070] S1. Hydrophobic surface treatment of lake:

[0071] First, 6 parts by weight of hydrophobic treatment agent (polyhydroxystearic acid) and 2 parts by weight of water are thoroughly mixed to obtain a mixed solution. Then, the above mixed solution is dropped onto 92 parts by weight of starch pigment (CI 15850 calcium lake) and simultaneously subjected to high-speed stirring (4000 rpm for 10 seconds). The stirring is repeated three times. Finally, the thoroughly mixed powder is placed in a drying oven for drying at 120°C for 2 hours to obtain a hydrophobic lake.

[0072] S2, Hydrophilic surface treatment of lake:

[0073] First, 24 parts by weight of hydrophobic starch pigment and 1 part by weight of amphiphilic copolymer (hydrogenated castor oil-polyethylene glycol) are thoroughly mixed to form a viscous paste. Then, 75 parts by weight of water are slowly added to the paste while stirring until the paste is fully dispersed to form a uniform lake dispersion. Then, stirring is continued for more than 1 hour. Finally, the lake dispersion is filtered to recover the starch pigment.

[0074] S3, freeze-drying treatment:

[0075] The lake treated in step S2 is then thoroughly dried using a freeze-drying process (pre-freezing at -40℃ for 4 hours, then vacuum drying at -20℃ for 24 hours) to obtain the finished product.

[0076] Example 6

[0077] A process for preparing a self-dispersing lake for use in water-based cosmetics, such as... Figure 1 As shown, it includes the following steps:

[0078] S1. Hydrophobic surface treatment of lake:

[0079] First, 1.5 parts by weight of hydrophobic treatment agent (including 1 part by weight of triethoxyoctylsilane and 0.5 parts by weight of polyhydroxystearic acid) and 2 parts by weight of water are thoroughly mixed to obtain a mixed solution. Then, the above mixed solution is dropped onto 96.5 parts by weight of pigment starch (CI 15850 calcium lake) and simultaneously subjected to high-speed stirring (4000 rpm for 10 seconds). The stirring is repeated three times. Finally, the thoroughly mixed powder is placed in a drying oven for drying at 120°C for 2 hours to obtain a hydrophobic lake.

[0080] S2, Hydrophilic surface treatment of lake:

[0081] First, 24 parts by weight of hydrophobic starch pigment and 6 parts by weight of amphiphilic copolymer (hydrogenated castor oil-polyethylene glycol) are thoroughly mixed to form a viscous paste. Then, 60 parts by weight of water are slowly added to the paste while stirring until the paste is fully dispersed to form a uniform lake dispersion. Then, stirring is continued for more than 1 hour. Finally, the lake dispersion is filtered to recover the starch pigment.

[0082] S3, freeze-drying treatment:

[0083] The lake treated in step S2 is then thoroughly dried using a freeze-drying process to obtain the finished product.

[0084] Comparative Example 1

[0085] Comparative Example 1 used the raw material component CI 42090 aluminum lake from Example 1, without any surface treatment of the lake.

[0086] Comparative Example 2

[0087] Comparative Example 2 is a comparative test case of Example 1:

[0088] Comparative Example 2 only applies the hydrophobic surface treatment in step S1 to the lake.

[0089] The following properties of the treated lakes obtained in Examples 1-6 and Comparative Examples 1 and 2 were tested:

[0090] 1. Dispersion effect test in water: The dispersion treatment method is as follows: the treated lake is added to water at 50℃ (5wt%) and its dispersion effect in water is tested.

[0091] 2. Dispersion stability test: The treated lake (5wt%) dispersed in water was left to stand at 50℃ for 24 hours, and the dispersion stability of the lake was then examined.

[0092] The test results are shown in Table 1.

[0093] Table 1

[0094]

[0095]

[0096] Figure 2 The images show actual photographs of the blue lake treated with hydrophobicity in Comparative Example 2 and the blue lake treated with dual surface treatment in Example 1 dispersed in water. It can be seen that the blue lake in Comparative Example 2, which only underwent hydrophobic treatment, is difficult to disperse in water, while the blue lake in Example 1, which underwent dual surface treatment, can be easily and quickly dispersed in water.

[0097] Figure 3 The images show inverted photographs of the untreated blue lake from Comparative Example 1 and the double-treated blue lake from Example 1, after being dispersed in water and left to stand at 50°C for 24 hours. The lake exhibits poor stability in the high-temperature aqueous solution. The untreated blue lake in Comparative Example 1 expands significantly after 24 hours of standing, and the inverted photograph clearly shows the formation of large solid clumps. In contrast, the double-treated blue lake in Example 1 demonstrates good stability, and the inverted photograph shows no large solid clumps formed.

[0098] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A process for preparing a self-dispersing lake for water-based cosmetics, characterized in that, Includes the following steps: S1. The surface of the lake is hydrophobically treated with a hydrophobic agent to obtain a hydrophobic lake; S2. The hydrophobic lake obtained in step S1 is self-assembled with the amphiphilic copolymer in water to hydrophilize the surface of the lake. S3. The lake treated in step S2 is then thoroughly dried using a freeze-drying process to obtain the finished product.

2. The preparation process of the self-dispersing lake for water-based cosmetics according to claim 1, characterized in that, In step S1, the hydrophobic treatment agent includes one or more of triethoxyoctylsilane, polyhydroxystearic acid, titanate, and polymethoxysiloxane.

3. The preparation process of the self-dispersing lake for water-based cosmetics according to claim 2, characterized in that, The hydrophobic treatment agent is a mixed solution of triethoxyoctylsilane and polyhydroxystearic acid in a mass ratio of 10:1 to 3:

1.

4. The preparation process of the self-dispersing lake for water-based cosmetics according to claim 3, characterized in that, In step S1, 2-10 parts by weight of hydrophobic treatment agent and 1-3 parts by weight of water are first thoroughly mixed to obtain a mixed solution. Then, the mixed solution is dropped onto 90-100 parts by weight of starch pigment while being stirred at high speed. Finally, the thoroughly mixed powder is placed in a drying oven for drying to obtain a hydrophobic lake.

5. The preparation process of the self-dispersing lake for water-based cosmetics according to claim 4, characterized in that, The drying temperature is 100-150℃, and the drying time is 2-5 hours.

6. The preparation process of the self-dispersing lake for water-based cosmetics according to claim 1, characterized in that, In step S2, the amphiphilic copolymer is hydrogenated castor oil-polyethylene glycol or polyhydroxystearic acid-polyethylene glycol.

7. The preparation process of the self-dispersing lake for water-based cosmetics according to claim 6, characterized in that, In step S2, 20-30 parts by weight of hydrophobic starch pigment and 1-6 parts by weight of amphiphilic copolymer are first thoroughly stirred and mixed to form a viscous paste. Then, 61-70 parts by weight of water are slowly added to the paste while stirring until the paste is fully dispersed to form a uniform lake dispersion. Then, stirring is continued for more than 1 hour. Finally, the lake dispersion is filtered to recover the starch pigment.

8. The preparation process of the self-dispersing lake for water-based cosmetics according to claim 7, characterized in that, The recovered starch chromophores were freeze-dried. The specific process was as follows: the freeze-drying procedure was to pre-freeze at -40℃ for 4 hours, and then vacuum dry at -40 to -20℃ for 8 to 24 hours.

9. A self-dispersing lake for use in water-based cosmetics, characterized in that, It is prepared by any one of the preparation processes described in claims 1-8.

Images