Preparation method for hydrophilic-modified zinc oxide

Abstract

A preparation method for hydrophilic-modified zinc oxide, comprising: dissolving 0.1-5 parts by weight of a modifier in a solvent, uniformly mixing the solution containing the modifier with 20 parts of zinc oxide powder, and drying the mixture at 100-150°C to obtain hydrophilic zinc oxide, wherein the modifier comprises polyglycerol.

Description

A method for preparing hydrophilic modified zinc oxide Technical Field

[0001] This application relates to the field of cosmetic technology, and more specifically, it relates to a method for preparing hydrophilic modified zinc oxide. Background Technology

[0002] Zinc oxide is an inorganic compound that usually exists as a white powder and has good stability. Its crystal structure is usually hexagonal wurtzite, exhibiting excellent physical and chemical properties, such as high refractive index, good light absorption, and antibacterial and antioxidant properties.

[0003] Zinc oxide, as a physical sunscreen, effectively reflects and scatters ultraviolet (UV) rays, providing broad-spectrum UV protection (UVA and UVB). Compared to chemical sunscreens, zinc oxide is not absorbed by the skin, making it more suitable for sensitive skin. Furthermore, it reduces free radical damage caused by UV rays, preventing photoaging. Zinc oxide's antibacterial properties also make it a common ingredient in treating skin problems such as acne, eczema, and diaper rash. It inhibits bacterial growth and has a soothing effect on damaged skin. In addition, zinc oxide is a natural mineral component, generally does not cause allergic reactions, and meets food-grade standards, making it commonly used in sensitive skin care products. Compared to chemical sunscreens, it is safer for use in products for children and pregnant women.

[0004] However, due to the poor hydrophilicity of zinc oxide, it often requires additional dispersants to achieve uniform distribution in water-based formulations (such as emulsions and sprays). This makes formulation design more complex, and if zinc oxide is not sufficiently dispersed, the product texture may become thick, viscous, or grainy, thus affecting the user's application experience. Summary of the Invention

[0005] To address the issue of poor hydrophilicity of zinc oxide, this application provides a method for preparing hydrophilic modified zinc oxide.

[0006] The preparation method of hydrophilic modified zinc oxide provided in this application adopts the following technical solution:

[0007] A method for preparing hydrophilic modified zinc oxide includes the following steps:

[0008] Dissolve 0.1-5 parts by weight of the modifier in a solvent, mix the solution containing the modifier with 20 parts of zinc oxide powder evenly, and dry at 100-150℃ to obtain hydrophilic zinc oxide; the modifier includes polyglycerol.

[0009] By employing the above-mentioned technical solution, polyglycerol, a hydrophilic polymer with a multi-hydroxyl structure, can form a hydrophilic film on the zinc oxide particle surface through hydrogen bonding with its hydroxyl groups during the modification process. This hydrophilic film effectively enhances the affinity of zinc oxide in aqueous systems, making it easy to disperse and stable in aqueous formulations such as emulsions and sprays. Improved dispersibility of zinc oxide in aqueous formulations results in a lighter and more uniform product texture. This modified zinc oxide no longer easily agglomerates into larger particles, thus avoiding the thick, sticky, or grainy feel common in traditional formulations. Ultimately, this improves the user's application experience, making the product easier to apply and absorb without leaving any discomfort on the skin. This hydrophilically modified zinc oxide is suitable for various aqueous formulations, including sunscreens, moisturizing lotions, and spray products. Especially in sunscreen formulations, the uniform distribution of zinc oxide directly affects the product's protective effect. After hydrophilic modification, zinc oxide can more evenly cover the skin surface, thereby enhancing sun protection and UV protection.

[0010] Optionally, the polyglycerol includes one of polyglycerol-3, polyglycerol-6, and polyglycerol-10.

[0011] By employing the above technical solutions, polyglycerol-3 molecules contain multiple hydroxyl groups, enabling them to form numerous hydrogen bonds with water molecules, effectively improving the hydrophilicity of zinc oxide. This improved hydrophilicity makes zinc oxide easier to disperse in aqueous systems, facilitating its uniform distribution in emulsions, sprays, and other water-based formulations, reducing agglomeration, thereby improving product texture, avoiding problems such as thick, viscous, or grainy textures caused by insufficient zinc oxide dispersion, preventing layering and sedimentation, and enhancing the user's application experience. Polyglycerol-6 has more hydroxyl groups than polyglycerol-3, resulting in stronger hydrophilicity. The larger molecular structure of polyglycerol-6 creates steric hindrance on the zinc oxide surface. When zinc oxide particles approach each other in an aqueous system, this steric hindrance prevents particle agglomeration, further improving the dispersion performance of zinc oxide. Polyglycerol-10 has a large molecular weight and strong hydrophilicity, and the hydrophilic layer it forms on the zinc oxide surface has good stability. During product storage and use, it can resist changes in environmental factors such as temperature and humidity, maintaining the hydrophilicity and dispersibility of zinc oxide for a long time.

[0012] Optionally, the modifier may also include polyethylene glycol.

[0013] By employing the above technical solution, polyethylene glycol (PEG) contains multiple hydroxyl groups in its molecular structure, and its interaction with the surface of zinc oxide particles can form a denser and more stable hydrophilic layer on the particle surface. When acting together with polyglycerol, PEG further enhances the coating effect of the modifier on the zinc oxide surface, resulting in modified zinc oxide particles exhibiting superior hydrophilicity, making them suitable for more complex aqueous formulation systems. In aqueous formulations (such as emulsions and spray products), uniform dispersion of zinc oxide is crucial for product performance. Due to its excellent solubility and wetting properties, PEG can enable zinc oxide to be more uniformly dispersed in the aqueous phase, reducing particle agglomeration. This effect results in a more uniform texture in the final product, reducing the grainy and heavy feel of the formulation and improving the user's application experience.

[0014] Optionally, the polyethylene glycol includes one of PEG-200, PEG-100, and PEG-10.

[0015] By employing the above technical solutions, when polyethylene glycol is selected from PEG-200, PEG-100, and PEG-10 respectively, it can synergistically modify zinc oxide with polyglycerol. PEG-200 has excellent hydrophilicity, dispersibility, flexibility, and covering power; PEG-100 has moderate hydrophilicity, which can optimize the dispersion effect; PEG-10 has efficient initial dispersion and rapid wetting ability, as well as the characteristics of enhancing system fluidity.

[0016] Optionally, the modifier comprises polyglycerol and polyethylene glycol mixed in a mass ratio of (1-3):1.

[0017] By employing the above technical solution, polyglycerol and polyethylene glycol are mixed in a ratio of (1-3):1, allowing for the full utilization of their functional properties. Polyglycerol provides strong hydrophilic modification, while polyethylene glycol provides good lubricity and dispersibility. This synergistic effect makes the composite modifier more effective than using either material alone, especially in aqueous formulations requiring long-term stable dispersion, significantly extending the product's shelf life.

[0018] Optional, the following steps may be included:

[0019] Dissolve 0.1-5 parts by weight of modifier in 20 parts of zinc oxide powder, mix evenly, and dry at 100-150℃ to obtain hydrophilic zinc oxide;

[0020] The hydrophilic zinc oxide obtained in the above steps was added to a 2-methacryloyloxyethyl phosphocholine solution. The reaction was carried out at 55-65℃ with a stirring speed of 200-500 r / min for 12-16 h. After the reaction was completed, the solid product was separated by centrifugation and then washed and dried to obtain hydrophilic zinc oxide grafted with phosphocholine.

[0021] By employing the above-mentioned technical solution, phosphocholine, with its high hydrophilicity and good biocompatibility, allows for more uniform and stable dispersion of zinc oxide in the aqueous phase of cosmetic formulations after grafting onto the surface of hydrophilic zinc oxide. This is crucial for water-based cosmetics, such as moisturizing lotions and serums, effectively preventing the rough texture caused by zinc oxide agglomeration, resulting in a smoother, more delicate texture that is easier to spread and provides a better user experience. Secondly, phosphocholine itself has a certain moisturizing effect; after grafting onto zinc oxide, it can better absorb and lock in moisture during cosmetic use, helping to maintain skin hydration and enhancing the moisturizing efficacy of cosmetics.

[0022] Optionally, azobisisobutyronitrile is also added to the mixed reaction solution of hydrophilic zinc oxide and 2-methacryloyloxyethyl phosphocholine solution, wherein the amount of azobisisobutyronitrile is 1-3% of the mass of hydrophilic zinc oxide.

[0023] By adopting the above technical solution, azobisisobutyronitrile decomposes to generate free radicals after heating, which promotes the grafting reaction between 2-methacryloyloxyethyl phosphocholine monomer and active sites on the surface of hydrophilic zinc oxide, making the grafting reaction more efficient and ensuring the grafting rate of phosphocholine on the zinc oxide surface.

[0024] Optionally, the modifier is mixed with zinc oxide powder in 2-5 equal parts by weight.

[0025] By adopting the above technical solution, adding all the modifier at once will make the reaction system too viscous, affecting the modification effect. Adding it in stages can avoid this phenomenon.

[0026] In summary, this application has the following beneficial effects:

[0027] 1. This application produces hydrophilic zinc oxide by mixing a polyglycerol modifier with zinc oxide powder and then drying it at 130-150℃. Polyglycerol, as a polyhydroxy hydrophilic polymer, forms hydrogen bonds with the zinc oxide surface through its hydroxyl groups, creating a hydrophilic film on the zinc oxide particles. This significantly enhances the affinity and dispersibility of zinc oxide in aqueous systems, improving the lightness and uniformity of the product texture, avoiding a grainy or heavy feel, and ultimately improving the application experience. The zinc oxide powder, after surface treatment, exhibits excellent hydrophilicity. Furthermore, the preparation method is simple, time-efficient, and low-cost, making it ideal for large-scale production. It has broad application prospects in the cosmetics, sunscreens, makeup, and skincare industries.

[0028] 2. In this application, the hydrophilic zinc oxide prepared by mixing polyglycerol and polyethylene glycol at a mass ratio of (1-3):1 as a modifier exhibits superior hydrophilicity. The hydroxyl groups in polyethylene glycol further enhance the coating effect on the particle surface, and work synergistically with polyglycerol to make zinc oxide more uniformly dispersed in aqueous formulations, reduce particle agglomeration, improve product texture, and enhance the application experience. The use of this composite modifier is particularly suitable for aqueous formulations such as emulsions and sprays, which can extend the storage stability of the product and improve its uniformity and protective effect.

[0029] 3. In this application, grafting phosphocholine onto the surface of hydrophilic zinc oxide is preferred, which can further improve the hydrophilicity of zinc oxide, making it more uniformly and stably dispersed in the aqueous phase system of cosmetics and preventing agglomeration; the free radicals generated by the thermal decomposition of azobisisobutyronitrile can promote the efficient progress of the grafting reaction and ensure the grafting rate of phosphocholine on the surface of zinc oxide. Detailed Implementation

[0030] The following detailed description of this application is provided in conjunction with the embodiments. It should be noted that: unless otherwise specified, the conditions in the following embodiments are performed under conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following embodiments are all from commercially available sources.

[0031] Example

[0032] Example 1

[0033] A method for preparing hydrophilic modified zinc oxide:

[0034] Mix 10g of modifier with 5g of deionized water and spray evenly onto the surface of 200g of zinc oxide powder (purchased from Maclean Reagent 768553) using a spray bottle. Then, use a stirrer to mix the modifier and zinc oxide powder evenly at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140℃ for 1h to obtain hydrophilic zinc oxide powder.

[0035] The modifier used was polyglycerol-10 (purchased from Maclean's reagent D909691).

[0036] Example 2

[0037] A method for preparing hydrophilic modified zinc oxide:

[0038] Mix 30g of modifier with 5g of deionized water, and spray the mixture evenly onto the surface of 200g of zinc oxide powder using a spray bottle. Then, use a stirrer to mix the modifier and zinc oxide powder evenly at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140℃ for 1h to obtain hydrophilic zinc oxide powder.

[0039] The modifier selected is polyglycerol-10.

[0040] Example 3

[0041] A method for preparing hydrophilic modified zinc oxide:

[0042] Mix 50g of modifier with 5g of deionized water, and spray the mixture evenly onto the surface of 200g of zinc oxide powder using a spray bottle. Then, use a stirrer to mix the modifier and zinc oxide powder evenly at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140℃ for 1h to obtain hydrophilic zinc oxide powder.

[0043] The modifier selected is polyglycerol-10.

[0044] Example 4

[0045] A method for preparing hydrophilic modified zinc oxide:

[0046] Mix 30g of modifier with 5g of deionized water, and spray the mixture evenly onto the surface of 200g of zinc oxide powder using a spray bottle. Then, use a stirrer to mix the modifier and zinc oxide powder evenly at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140℃ for 1h to obtain hydrophilic zinc oxide powder.

[0047] The modifier selected is polyglycerol-3.

[0048] Example 5

[0049] A method for preparing hydrophilic modified zinc oxide:

[0050] Mix 30g of modifier with 5g of deionized water, and spray the mixture evenly onto the surface of 200g of zinc oxide powder using a spray bottle. Then, use a stirrer to mix the modifier and zinc oxide powder evenly at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140℃ for 1h to obtain hydrophilic zinc oxide powder.

[0051] The modifier selected is polyglycerol-6.

[0052] Example 6

[0053] A method for preparing hydrophilic modified zinc oxide:

[0054] Mix 30g of modifier with 5g of deionized water and spray evenly onto the surface of 200g of zinc oxide powder using a spray bottle. Then, use a stirrer to mix the modifier and zinc oxide powder evenly at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140℃ for 1h to obtain hydrophilic zinc oxide powder.

[0055] The modifier used was PEG-200 (purchased from Merck Reagent P3015).

[0056] Example 7

[0057] A method for preparing hydrophilic modified zinc oxide:

[0058] Mix 30g of modifier with 5g of deionized water and spray evenly onto the surface of 200g of zinc oxide powder using a spray bottle. Then, use a stirrer to mix the modifier and zinc oxide powder evenly at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140℃ for 1h to obtain hydrophilic zinc oxide powder.

[0059] The modifier used is PEG-100.

[0060] Example 8

[0061] A method for preparing hydrophilic modified zinc oxide:

[0062] Mix 30g of modifier with 5g of deionized water and spray evenly onto the surface of 200g of zinc oxide powder using a spray bottle. Then, use a stirrer to mix the modifier and zinc oxide powder evenly at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140℃ for 1h to obtain hydrophilic zinc oxide powder.

[0063] The modifier used is PEG-10.

[0064] Example 9

[0065] A method for preparing hydrophilic modified zinc oxide:

[0066] Mix 30g of modifier with 5g of deionized water and spray evenly onto the surface of 200g of zinc oxide powder using a spray bottle. Then, use a stirrer to mix the modifier and zinc oxide powder evenly at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140℃ for 1h to obtain hydrophilic zinc oxide powder.

[0067] The modifiers used are 20g polyglycerol-10 and 10g PEG-200.

[0068] Example 10

[0069] A method for preparing hydrophilic modified zinc oxide:

[0070] Mix 30g of modifier with 5g of deionized water and spray evenly onto the surface of 200g of zinc oxide powder using a spray bottle. Then, use a stirrer to mix the modifier and zinc oxide powder evenly at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140℃ for 1h to obtain hydrophilic zinc oxide powder.

[0071] The modifiers selected are 15g polyglycerol-10 and 15g PEG-200.

[0072] Example 11

[0073] A method for preparing hydrophilic modified zinc oxide:

[0074] Mix 30g of modifier with 5g of deionized water and spray evenly onto the surface of 200g of zinc oxide powder using a spray bottle. Then, use a stirrer to mix the modifier and zinc oxide powder evenly at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140℃ for 1h to obtain hydrophilic zinc oxide powder.

[0075] The modifiers selected are 22.5g polyglycerol-10 and 7.5g PEG-200.

[0076] Example 12

[0077] A method for preparing hydrophilic modified zinc oxide:

[0078] Mix 30g of modifier with 5g of deionized water, and spray the mixture evenly onto the surface of 200g of zinc oxide powder using a spray bottle. Then, use a stirrer to mix the modifier and zinc oxide powder evenly at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140℃ for 1h to obtain hydrophilic zinc oxide powder.

[0079] The hydrophilic zinc oxide obtained in the above steps was added to 400g of a 25% (w / w) solution of 2-methacryloyloxyethyl phosphocholine. The reaction was carried out at 60°C and a stirring speed of 300r / min for 14h. After the reaction was completed, the solid product was separated by centrifugation, washed with ethanol, and then dried under vacuum at 80°C to obtain hydrophilic zinc oxide grafted with phosphocholine.

[0080] The modifiers used are 20g polyglycerol-10 and 10g PEG-200.

[0081] Example 13

[0082] A method for preparing hydrophilic modified zinc oxide:

[0083] Mix 30g of modifier with 5g of deionized water, and spray the mixture evenly onto the surface of 200g of zinc oxide powder using a spray bottle. Then, use a stirrer to mix the modifier and zinc oxide powder evenly at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140℃ for 1h to obtain hydrophilic zinc oxide powder.

[0084] The hydrophilic zinc oxide obtained in the above steps was added to 400g of a 25% (w / w) solution of 2-methacryloyloxyethyl phosphocholine, followed by 4g of azobisisobutyronitrile. The reaction was carried out at 60℃ and a stirring speed of 300r / min for 14h. After the reaction was completed, the solid product was separated by centrifugation, washed with ethanol, and then dried under vacuum at 80℃ to obtain hydrophilic zinc oxide grafted with phosphocholine.

[0085] The modifiers used are 20g polyglycerol-10 and 10g PEG-200.

[0086] Example 14

[0087] A method for preparing hydrophilic modified zinc oxide:

[0088] Mix 30g of modifier with 5g of deionized water and divide the mixture into three equal parts by weight. Spray one part of the modifier solution evenly onto the surface of 200g of zinc oxide powder using a spray bottle. Then, mix the modifier and zinc oxide powder together using a stirrer at a speed of 1000r / min. Spray the remaining two parts of the modifier solution every 3 minutes. Stir for 10 minutes to complete the mixing. Place the zinc oxide mixture in an oven and dry it at 140℃ for 1 hour to obtain hydrophilic zinc oxide powder.

[0089] The hydrophilic zinc oxide obtained in the above steps was added to 400g of a 25% (w / w) solution of 2-methacryloyloxyethyl phosphocholine, followed by 4g of azobisisobutyronitrile. The reaction was carried out at 60℃ and a stirring speed of 300r / min for 14h. After the reaction was completed, the solid product was separated by centrifugation, washed with ethanol, and then dried under vacuum at 80℃ to obtain hydrophilic zinc oxide grafted with phosphocholine.

[0090] The modifiers used are 20g polyglycerol-10 and 10g PEG-200.

[0091] Comparative Example

[0092] Comparative Example 1

[0093] A method for preparing hydrophilic modified zinc oxide:

[0094] 5g of modifier was evenly sprayed onto the surface of 200g of zinc oxide powder using a spray bottle. Then, the modifier and zinc oxide powder were mixed evenly using a stirrer at a speed of 1000r / min for 10min. After mixing, the zinc oxide mixture was placed in an oven and dried at 140℃ for 1h to obtain hydrophilic zinc oxide powder.

[0095] The modifier selected is polyglycerol-10.

[0096] Comparative Example 2

[0097] A method for preparing hydrophilic modified zinc oxide:

[0098] 55g of modifier was evenly sprayed onto the surface of 200g of zinc oxide powder using a spray bottle. Then, the modifier and zinc oxide powder were mixed evenly using a stirrer at a speed of 1000r / min for 10min. After mixing, the zinc oxide mixture was placed in an oven and dried at 140℃ for 1h to obtain hydrophilic zinc oxide powder.

[0099] The modifier selected is polyglycerol-10.

[0100] Comparative Example 3

[0101] A method for preparing hydrophilic modified zinc oxide:

[0102] 30g of modifier was evenly sprayed onto the surface of 200g of zinc oxide powder using a spray bottle. Then, the modifier and zinc oxide powder were mixed evenly using a stirrer at a speed of 1000r / min for 10min. After mixing, the zinc oxide mixture was placed in an oven and dried at 140℃ for 1h to obtain hydrophilic zinc oxide powder.

[0103] The modifiers selected are 10g polyglycerol-10 and 20g PEG-200.

[0104] Comparative Example 4

[0105] A method for preparing hydrophilic modified zinc oxide:

[0106] 30g of modifier was evenly sprayed onto the surface of 200g of zinc oxide powder using a spray bottle. Then, the modifier and zinc oxide powder were mixed evenly using a stirrer at a speed of 1000r / min for 10min. After mixing, the zinc oxide mixture was placed in an oven and dried at 140℃ for 1h to obtain hydrophilic zinc oxide powder.

[0107] The modifiers used are 24g polyglycerol-10 and 6g PEG-200.

[0108] Performance testing

[0109] Detection methods

[0110] Take 1g of hydrophilic modified zinc oxide powder and add it to 100g of deionized water. Stir with a magnetic stirrer for 30 minutes to ensure that the zinc oxide powder and water are fully mixed.

[0111] After stirring, let the solution stand for 5 hours to allow the undissolved zinc oxide particles to settle naturally to the bottom of the container.

[0112] Filter the solution using filter paper and collect the filtrate. Dry the filtrate in a drying oven and weigh the residue. Calculate the solubility of the hydrophilic modified zinc oxide using the difference method.

[0113] Table 1 Solubility data

[0114] As can be seen from Examples 1-3 and Comparative Examples 1-2, and Table 1, when the modifier dosage is too low, it is difficult to form a sufficient hydrophilic film on the zinc oxide surface, resulting in poor dispersion in the aqueous system. Increased interparticle interaction leads to easy precipitation of zinc oxide in the system and uneven distribution in the aqueous phase. Excessive modifier dosage causes adhesion between zinc oxide particles, affecting their dispersibility in the aqueous formulation and thus their solubility.

[0115] As can be seen from Examples 9-11 and Comparative Examples 3-4, and in conjunction with Table 1, a mixture of polyglycerol and polyethylene glycol in a ratio of (1-3):1 can fully utilize the functional properties of both. Polyglycerol provides strong hydrophilic modification, while polyethylene glycol provides good lubricity and dispersibility. However, a ratio that is too high or too low will weaken their synergistic effect.

[0116] As can be seen from Examples 1-11 and Table 1, the optimal amount of modifier in this application is 1-5 parts by weight, which ensures the modification effect without causing excessive waste. Both polyglycerol and polyethylene glycol can achieve good modification effects. By mixing polyglycerol and polyethylene glycol at a mass ratio of (1-3):1 as a modifier, mixing with zinc oxide powder, and drying, the prepared hydrophilic zinc oxide exhibits superior hydrophilicity.

[0117] As can be seen from Examples 9 and 12-13 and Table 1, after grafting phosphocholine onto the surface of hydrophilic zinc oxide, the hydrophilicity of zinc oxide is further enhanced, allowing for more uniform and stable dispersion of zinc oxide in the aqueous system. Azobisisobutyronitrile decomposes upon heating to generate free radicals, promoting the grafting reaction between the 2-methacryloyloxyethylphosphocholine monomer and the active sites on the hydrophilic zinc oxide surface, thus making the grafting reaction more efficient.

[0118] As can be seen from Examples 13-14 and Table 1, adding all the modifier at once will make the reaction system too viscous, affecting the modification effect. Adding it in stages can avoid this phenomenon.

[0119] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing hydrophilic modified zinc oxide, characterized in that, Includes the following steps: Dissolve 0.1-5 parts by weight of the modifier in a solvent, mix the solution containing the modifier with 20 parts of zinc oxide powder evenly, and dry at 100-150℃ to obtain hydrophilic zinc oxide; the modifier includes polyglycerol.

2. The method for preparing hydrophilic modified zinc oxide according to claim 1, characterized in that: The polyglycerol includes one of polyglycerol-3, polyglycerol-6, and polyglycerol-10.

3. The method for preparing hydrophilic modified zinc oxide according to claim 1, characterized in that: The modifier also includes polyethylene glycol.

4. The method for preparing hydrophilic modified zinc oxide according to claim 3, characterized in that: The polyethylene glycol includes one of PEG-200, PEG-100, and PEG-10.

5. The method for preparing hydrophilic modified zinc oxide according to claim 1, characterized in that: The modifier comprises polyglycerol and polyethylene glycol mixed in a mass ratio of (1-3):

1.

6. The method for preparing hydrophilic modified zinc oxide according to claim 1, characterized in that: Includes the following steps: Dissolve 0.1-5 parts by weight of modifier in 20 parts of zinc oxide powder, mix evenly, and dry at 100-150℃ to obtain hydrophilic zinc oxide; The hydrophilic zinc oxide obtained in the above steps was added to a 2-methacryloyloxyethyl phosphocholine solution. The reaction was carried out at 55-65℃ with a stirring speed of 200-500 r / min for 12-16 h. After the reaction was completed, the solid product was separated by centrifugation and then washed and dried to obtain hydrophilic zinc oxide grafted with phosphocholine.

7. The method for preparing hydrophilic modified zinc oxide according to claim 6, characterized in that: The mixed reaction solution of hydrophilic zinc oxide and 2-methacryloyloxyethyl phosphocholine solution also contains azobisisobutyronitrile, the amount of which is 1-3% of the mass of hydrophilic zinc oxide.

8. The method for preparing hydrophilic modified zinc oxide according to claim 1, characterized in that: The modifier is mixed with zinc oxide powder in 2-5 equal parts by weight.

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