Preparation method of hydrophilic modified zinc oxide

Abstract

The invention relates to the technical field of cosmetics, and particularly discloses a preparation method of hydrophilic modified zinc oxide. The preparation method of the hydrophilic modified zinc oxide comprises the following steps: dissolving 0.1-5 parts by weight of a modifier in a solvent, uniformly mixing the solution containing the modifier with 20 parts by weight of zinc oxide powder, and drying at 100-150 DEG C to obtain hydrophilic zinc oxide; the modifier comprises polyglycerol. According to the preparation method of the hydrophilic modified zinc oxide, the problem of poor hydrophilicity of zinc oxide is solved, and the preparation method has the advantages of excellent hydrophilicity, simplicity, short time consumption and low cost.

Description

Technical Field

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

[0002] Zinc oxide is an inorganic compound that usually exists in the form of white powder with good stability. Its crystal structure is usually hexagonal wurtzite, showing excellent physical and chemical properties, such as high refractive index, good light absorption ability, and antibacterial and antioxidant properties.

[0003] As a physical sunscreen, zinc oxide can effectively reflect and scatter UV rays, providing broad-spectrum UV protection (UVA and UVB). Compared with chemical sunscreens, zinc oxide is not absorbed by the skin, making it more friendly to sensitive skin. In addition, it reduces free radical damage to the skin caused by UV rays and avoids the occurrence of photoaging. And the antibacterial properties of zinc oxide make it a common ingredient for treating skin problems such as acne, eczema and diaper rash. It can inhibit the growth of pathogens and has a calming effect on damaged skin. In addition, zinc oxide is a natural mineral ingredient that usually does not cause allergic reactions and meets food grade standards, so it is often used in sensitive skin care products. Compared with chemical sunscreens, it is safer when used in children's and pregnant women's products.

[0004] However, due to its poor hydrophilicity, zinc oxide often requires additional dispersants to evenly distribute in water-based formulas (such as emulsions and spray products). This makes formula design more complicated, and if zinc oxide is not fully dispersed, the texture of the product becomes thick, sticky or granular, which affects the user's application experience. Summary of the invention

[0005] In order to solve the problem of poor hydrophilicity of zinc oxide, the present application provides a method for preparing hydrophilic modified zinc oxide.

[0006] The present application provides a method for preparing a hydrophilic modified zinc oxide using the following technical scheme: A method for preparing hydrophilic modified zinc oxide comprises the following steps: 0.1-5 parts of a modifier by weight are dissolved in a solvent, the solution containing the modifier is evenly mixed with 20 parts of zinc oxide powder, and dried at 100-150° C. to obtain hydrophilic zinc oxide; the modifier includes polyglycerol.

[0007] By adopting the above technical scheme, polyglycerol is a hydrophilic polymer with a polyhydroxy structure. During the modification process, polyglycerol can form a hydrophilic film on the surface of zinc oxide through its hydroxyl group, thereby forming a hydrophilic film on the surface of zinc oxide particles. This hydrophilic film can effectively enhance the affinity of zinc oxide in the aqueous system, making it easy to disperse and stabilize in aqueous formulas such as emulsions and sprays. The dispersibility of zinc oxide in aqueous formulas is improved, making the texture of the product lighter and more uniform. The modified zinc oxide is no longer easy to agglomerate into larger particles, thus avoiding the heavy, sticky or granular feeling common in traditional formulas. Ultimately, the user's application experience is improved, the product is easier to apply and absorb, and will not leave discomfort on the skin. The hydrophilic modified zinc oxide is suitable for various aqueous formulas, including sunscreens, moisturizing lotions, spray products, etc. Especially in sunscreen formulas, the uniform distribution of zinc oxide directly affects the protective effect of the product. After hydrophilic modification, zinc oxide can cover the skin surface more evenly, thereby improving the sun protection and anti-ultraviolet effects.

[0008] Optionally, the polyglycerol includes one of polyglycerol-3, polyglycerol-6 and polyglycerol-10.

[0009] By adopting the above technical solution, the polyglycerol-3 molecule contains multiple hydroxyl groups, which can form a large number of hydrogen bonds with water molecules, effectively improving the hydrophilicity of zinc oxide. This improvement in hydrophilicity makes zinc oxide easier to disperse in aqueous systems, helps it to be evenly distributed in aqueous formula products such as emulsions and sprays, reduces agglomeration, thereby improving the texture of the product, avoiding the problem of heavy texture, stickiness or granularity caused by insufficient dispersion of zinc oxide, preventing stratification and precipitation, and improving the user's application experience. Polyglycerol-6 has more hydroxyl groups than polyglycerol-3 and is more hydrophilic. The larger molecular structure of polyglycerol-6 forms a certain steric hindrance on the surface of zinc oxide. When zinc oxide particles are close to each other in an aqueous system, this steric hindrance can prevent the agglomeration of particles and further improve the dispersion performance of zinc oxide. Polyglycerol-10 has a large molecular weight and strong hydrophilicity, and the hydrophilic layer formed on the surface of zinc oxide has good stability. During the storage and use of the product, it can resist changes in environmental factors such as temperature and humidity, and maintain the hydrophilicity and dispersibility of zinc oxide for a long time.

[0010] Optionally, the modifier further includes polyethylene glycol.

[0011] By adopting the above technical solution, the polyethylene glycol molecular structure contains multiple hydroxyl groups, and its interaction with the surface of zinc oxide particles can form a denser and more stable hydrophilic layer on the surface of the particles. When acting together with polyglycerol, polyethylene glycol further enhances the coating effect of the modifier on the surface of zinc oxide, so that the modified zinc oxide particles show better hydrophilicity and are suitable for more complex water-based formulation systems. In water-based formulations (such as emulsions and spray products), the uniform dispersion of zinc oxide is the key to product performance. Due to its good solubility and wettability, polyethylene glycol can make zinc oxide more evenly dispersed in the aqueous phase and reduce particle agglomeration. This effect makes the texture of the final product more uniform, reduces the granularity and heaviness in the formula, and enhances the user's application experience.

[0012] Optionally, the polyethylene glycol includes one of PEG-200, PEG-100, and PEG-10.

[0013] By adopting the above technical scheme, when polyethylene glycol is selected as one of PEG-200, PEG-100 and PEG-10, it can cooperate with polyglycerol to modify zinc oxide. PEG-200 has excellent hydrophilicity, dispersibility, flexibility and coverage; PEG-100 has moderate hydrophilicity and can optimize the dispersion effect; PEG-10 has the characteristics of efficient initial dispersion and rapid wetting ability and enhanced system fluidity.

[0014] Optionally, the modifier includes polyglycerol and polyethylene glycol mixed in a mass ratio of (1-3):1.

[0015] By adopting the above technical solution, polyglycerol and polyethylene glycol are mixed in a ratio of (1-3):1, and the functional properties of both can be fully utilized. 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 water-based formulations that require long-term stable dispersion, which can significantly extend the storage stability of the product.

[0016] Optionally, include the following steps: Dissolve 0.1-5 parts of the modifier by weight in 20 parts of zinc oxide powder, mix well, and dry at 100-150° C. to obtain hydrophilic zinc oxide; The hydrophilic zinc oxide obtained in the above step is added to the 2-methacryloyloxyethyl phosphorylcholine solution, and the reaction time is 12-16 hours at 55-65° C. and a stirring speed of 200-500 r / min. After the reaction is completed, the solid product is separated by centrifugation, and washed and dried to obtain the hydrophilic zinc oxide grafted with phosphorylcholine.

[0017] By adopting the above technical solution, phosphorylcholine has high hydrophilicity and good biocompatibility. After phosphorylcholine is grafted onto the hydrophilic zinc oxide surface, zinc oxide can be more evenly and stably dispersed in the aqueous phase system of the cosmetic formula. This is crucial for water-based cosmetics, such as moisturizing lotions and essences. It can effectively prevent the rough texture of the product caused by zinc oxide agglomeration, making the product texture more delicate and smooth, easier to spread when applied, and bringing consumers a better feel. Secondly, phosphorylcholine itself has a certain moisturizing effect. After being grafted onto zinc oxide, it can better absorb and lock moisture during the use of cosmetics, which helps to maintain the moisture of the skin and enhance the moisturizing effect of cosmetics.

[0018] Optionally, azobisisobutyronitrile is further added to the mixed reaction liquid of the hydrophilic zinc oxide and the 2-methacryloyloxyethyl phosphorylcholine solution, and the amount of azobisisobutyronitrile is 1-3% of the mass of the hydrophilic zinc oxide.

[0019] By adopting the above technical scheme, azobisisobutyronitrile decomposes to generate free radicals after heating, which promotes the grafting reaction of 2-methacryloyloxyethyl phosphorylcholine monomer with the active sites on the surface of hydrophilic zinc oxide, making the grafting reaction more efficient and ensuring the grafting rate of phosphorylcholine on the surface of zinc oxide.

[0020] Optionally, the modifier is mixed with zinc oxide powder in 2-5 equal portions by weight.

[0021] By adopting the above technical solution, adding all the modifiers at one time will make the reaction system too viscous, affecting the modification effect, while adding in batches can avoid this phenomenon.

[0022] In summary, this application has the following beneficial effects: 1. This application prepares hydrophilic zinc oxide by mixing a polyglycerol modifier with zinc oxide powder and drying it at 130-150°C. Polyglycerol, as a polyhydroxy hydrophilic polymer, forms hydrogen bonds with the surface of zinc oxide through its hydroxyl groups to form a hydrophilic film on the surface of zinc oxide particles, which significantly enhances the affinity and dispersibility of zinc oxide in aqueous systems, improves the lightness and uniformity of the product texture, avoids granularity and heaviness, and ultimately improves the application experience. After surface treatment, zinc oxide powder has excellent hydrophilicity. At the same time, the preparation method is simple, time-saving and low-cost, which is very suitable for large-scale production. It has broad application prospects in the cosmetics sunscreen, makeup and skin care industries.

[0023] 2. In the present application, the hydrophilic zinc oxide prepared by mixing polyglycerol and polyethylene glycol in a mass ratio of (1-3):1 as a modifier exhibits better hydrophilicity. The hydroxyl groups in polyethylene glycol further enhance the coating effect on the particle surface, and synergize with polyglycerol to make zinc oxide more evenly dispersed in the aqueous formula, reduce particle agglomeration, improve product texture, and enhance the application experience. The use of this composite modifier is particularly suitable for aqueous formulas such as emulsions and sprays, which can prolong the storage stability of the product and improve its uniformity and protective effect.

[0024] 3. In the present application, it is preferred to graft phosphorylcholine onto the surface of hydrophilic zinc oxide to further improve the hydrophilicity of zinc oxide, so that it can be more evenly and stably dispersed in the aqueous phase system of cosmetics to prevent agglomeration; azobisisobutyronitrile decomposes under heat to produce free radicals, which can promote the efficient grafting reaction and ensure the grafting rate of phosphorylcholine on the surface of zinc oxide. DETAILED DESCRIPTION

[0025] The present application is further described in detail below in conjunction with the examples. It is particularly noted that if no specific conditions are specified in the following examples, the experiments are carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources. Example

[0026] Example 1 A preparation method of hydrophilic modified zinc oxide: Mix 10g of the modifier with 5g of deionized water, and evenly spray it on the surface of 200g of zinc oxide powder (purchased from McLean reagent 768553) through a spray bottle, and then use a stirrer to evenly mix the modifier and zinc oxide powder at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140°C for 1h to obtain hydrophilic zinc oxide powder.

[0027] Among them, the modifier is polyglycerol-10 (purchased from McLean reagent D909691).

[0028] Example 2 A preparation method of hydrophilic modified zinc oxide: Mix 30g of the modifier with 5g of deionized water, spray it evenly on the surface of 200g of zinc oxide powder through a spray bottle, and 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°C for 1h to obtain hydrophilic zinc oxide powder.

[0029] Among them, the modifier is polyglycerol-10.

[0030] Example 3 A preparation method of hydrophilic modified zinc oxide: Mix 50g of the modifier with 5g of deionized water, spray it evenly on the surface of 200g of zinc oxide powder through a spray bottle, and 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°C for 1h to obtain hydrophilic zinc oxide powder.

[0031] Among them, the modifier is polyglycerol-10.

[0032] Example 4 A preparation method of hydrophilic modified zinc oxide: Mix 30g of the modifier with 5g of deionized water, spray it evenly on the surface of 200g of zinc oxide powder through a spray bottle, and 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°C for 1h to obtain hydrophilic zinc oxide powder.

[0033] Among them, the modifier is polyglycerol-3.

[0034] Example 5 A preparation method of hydrophilic modified zinc oxide: Mix 30g of the modifier with 5g of deionized water, spray it evenly on the surface of 200g of zinc oxide powder through a spray bottle, and 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°C for 1h to obtain hydrophilic zinc oxide powder.

[0035] Among them, the modifier is polyglycerol-6.

[0036] Example 6 A preparation method of hydrophilic modified zinc oxide: Mix 30g of the modifier with 5g of deionized water, and spray it evenly on the surface of 200g of zinc oxide powder through a spray bottle. Then use a stirrer to evenly mix the modifier and zinc oxide powder at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140°C for 1h to obtain hydrophilic zinc oxide powder.

[0037] Among them, PEG-200 (purchased from Merck reagent P3015) was selected as the modifier.

[0038] Example 7 A preparation method of hydrophilic modified zinc oxide: Mix 30g of the modifier with 5g of deionized water, and spray it evenly on the surface of 200g of zinc oxide powder through a spray bottle. Then use a stirrer to evenly mix the modifier and zinc oxide powder at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140°C for 1h to obtain hydrophilic zinc oxide powder.

[0039] Among them, PEG-100 is selected as the modifier.

[0040] Example 8 A preparation method of hydrophilic modified zinc oxide: Mix 30g of the modifier with 5g of deionized water, and spray it evenly on the surface of 200g of zinc oxide powder through a spray bottle. Then use a stirrer to evenly mix the modifier and zinc oxide powder at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140°C for 1h to obtain hydrophilic zinc oxide powder.

[0041] Among them, PEG-10 is selected as the modifier.

[0042] Example 9 A preparation method of hydrophilic modified zinc oxide: Mix 30g of the modifier with 5g of deionized water, and spray it evenly on the surface of 200g of zinc oxide powder through a spray bottle. Then use a stirrer to evenly mix the modifier and zinc oxide powder at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140°C for 1h to obtain hydrophilic zinc oxide powder.

[0043] Among them, the modifiers are 20g polyglycerol-10 and 10g PEG-200.

[0044] Example 10 A preparation method of hydrophilic modified zinc oxide: Mix 30g of the modifier with 5g of deionized water, and spray it evenly on the surface of 200g of zinc oxide powder through a spray bottle. Then use a stirrer to evenly mix the modifier and zinc oxide powder at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140°C for 1h to obtain hydrophilic zinc oxide powder.

[0045] Among them, the modifiers are 15g polyglycerol-10 and 15g PEG-200.

[0046] Embodiment 11 A preparation method of hydrophilic modified zinc oxide: Mix 30g of the modifier with 5g of deionized water, and spray it evenly on the surface of 200g of zinc oxide powder through a spray bottle. Then use a stirrer to evenly mix the modifier and zinc oxide powder at a speed of 1000r / min for 10min. After mixing, place the zinc oxide mixture in an oven and dry it at 140°C for 1h to obtain hydrophilic zinc oxide powder.

[0047] Among them, the modifiers are 22.5g polyglycerol-10 and 7.5g PEG-200.

[0048] Example 12 A preparation method of hydrophilic modified zinc oxide: 30g of the modifier and 5g of deionized water were mixed and evenly sprayed on the surface of 200g of zinc oxide powder through a spray pot, and then the modifier and zinc oxide powder were evenly mixed by 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°C for 1h to obtain hydrophilic zinc oxide powder; The hydrophilic zinc oxide obtained in the above step is added to 400 g of a solution of 2-methacryloyloxyethyl phosphorylcholine with a mass concentration of 25%, and the reaction time is 14 h at 60° C. and a stirring speed of 300 r / min. After the reaction is completed, the solid product is separated by a centrifuge, and the product is washed with ethanol and then vacuum dried at 80° C. to obtain hydrophilic zinc oxide grafted with phosphorylcholine.

[0049] Among them, the modifiers are 20g polyglycerol-10 and 10g PEG-200.

[0050] Example 13 A preparation method of hydrophilic modified zinc oxide: 30g of the modifier and 5g of deionized water were mixed and evenly sprayed on the surface of 200g of zinc oxide powder through a spray pot, and then the modifier and zinc oxide powder were evenly mixed by 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°C for 1h to obtain hydrophilic zinc oxide powder; The hydrophilic zinc oxide obtained in the above step is added to 400g of a solution of 2-methacryloyloxyethyl phosphorylcholine with a mass concentration of 25%, and then 4g of azobisisobutyronitrile is added. The reaction time is 14h at 60°C and a stirring speed of 300r / min. After the reaction is completed, the solid product is separated by a centrifuge, and the product is washed with ethanol and then vacuum dried at 80°C to obtain hydrophilic zinc oxide grafted with phosphorylcholine.

[0051] Among them, the modifiers are 20g polyglycerol-10 and 10g PEG-200.

[0052] Embodiment 14 A preparation method of hydrophilic modified zinc oxide: 30g of the modifier and 5g of deionized water were mixed and divided into 3 parts by weight, 1 part of the modifier solution was evenly sprayed on the surface of 200g of zinc oxide powder through a spray pot, and then the modifier and zinc oxide powder were mixed by a stirrer at a speed of 1000r / min, and the remaining 2 parts of the modifier solution were sprayed once every 3min, and the mixing time was 10min. The zinc oxide mixture was placed in an oven and dried at 140°C for 1h to obtain hydrophilic zinc oxide powder; The hydrophilic zinc oxide obtained in the above step is added to 400g of a solution of 2-methacryloyloxyethyl phosphorylcholine with a mass concentration of 25%, and then 4g of azobisisobutyronitrile is added. The reaction time is 14h at 60°C and a stirring speed of 300r / min. After the reaction is completed, the solid product is separated by a centrifuge, and the product is washed with ethanol and then vacuum dried at 80°C to obtain hydrophilic zinc oxide grafted with phosphorylcholine.

[0053] Among them, the modifiers are 20g polyglycerol-10 and 10g PEG-200.

[0054] Comparative Example Comparative Example 1 A preparation method of hydrophilic modified zinc oxide: 5 g of the modifier was evenly sprayed on the surface of 200 g of zinc oxide powder through a spray bottle, and then the modifier and zinc oxide powder were evenly mixed by a stirrer at a speed of 1000 r / min for 10 min. After mixing, the zinc oxide mixture was placed in an oven and dried at 140° C. for 1 h to obtain hydrophilic zinc oxide powder.

[0055] Among them, the modifier is polyglycerol-10.

[0056] Comparative Example 2 A preparation method of hydrophilic modified zinc oxide: 55 g of the modifier was evenly sprayed on the surface of 200 g of zinc oxide powder through a spray bottle, and then the modifier and zinc oxide powder were evenly mixed by a stirrer at a speed of 1000 r / min for 10 min. After mixing, the zinc oxide mixture was placed in an oven and dried at 140° C. for 1 h to obtain hydrophilic zinc oxide powder.

[0057] Among them, the modifier is polyglycerol-10.

[0058] Comparative Example 3 A preparation method of hydrophilic modified zinc oxide: 30g of the modifier was evenly sprayed on the surface of 200g of zinc oxide powder through a spray bottle, and then the modifier and zinc oxide powder were evenly mixed by 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°C for 1h to obtain hydrophilic zinc oxide powder.

[0059] Among them, the modifiers are 10g polyglycerol-10 and 20g PEG-200.

[0060] Comparative Example 4 A preparation method of hydrophilic modified zinc oxide: 30g of the modifier was evenly sprayed on the surface of 200g of zinc oxide powder through a spray bottle, and then the modifier and zinc oxide powder were evenly mixed by 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°C for 1h to obtain hydrophilic zinc oxide powder.

[0061] Among them, the modifiers are 24g polyglycerol-10 and 6g PEG-200.

[0062] Performance testing Detection Methods Take 1g of hydrophilic modified zinc oxide powder and add it to 100g of deionized water. Use a magnetic stirrer to stir for 30 minutes to ensure that the zinc oxide powder and water are fully mixed.

[0063] After stirring, the solution was allowed to stand for 5 h to allow the undissolved zinc oxide particles to naturally settle to the bottom of the container.

[0064] Filter the solution with filter paper and collect the filtrate. Dry the filtrate in a drying oven and weigh the mass of the residue. Calculate the solubility of the hydrophilic modified zinc oxide by subtraction method.

[0065] Table 1 Solubility data Combining Examples 1-3 and Comparative Examples 1-2 with Table 1, it can be seen that when the amount of modifier is too low, it is difficult to form a sufficient hydrophilic film on the surface of zinc oxide, resulting in poor dispersion in the aqueous system, increased interaction between particles, and easy precipitation of zinc oxide in the system, and uneven distribution in the aqueous phase. Excessive use of the modifier causes mutual adhesion between zinc oxide particles, affecting the dispersibility of the particles in the aqueous formulation, thereby affecting their dissolution.

[0066] Combining Examples 9-11 and Comparative Examples 3-4 with Table 1, it can be seen that the functional properties of polyglycerol and polyethylene glycol can be fully exerted by mixing them in a ratio of (1-3):1. Polyglycerol provides strong hydrophilic modification, while polyethylene glycol provides good lubricity and dispersibility. However, too high or too low a ratio will weaken their synergistic effect.

[0067] It can be seen from Examples 1-11 and Table 1 that the amount of modifier used is 1-5 parts by weight, which is the best for this application, ensuring the modification effect and not causing unnecessary waste. Both polyglycerol and polyethylene glycol can achieve good modification effects. By mixing polyglycerol and polyethylene glycol in a mass ratio of (1-3):1 as a modifier, mixing with zinc oxide powder and drying, the prepared hydrophilic zinc oxide exhibits more excellent hydrophilicity.

[0068] It can be seen from Example 9 and Examples 12-13 and Table 1 that after phosphorylcholine is grafted onto the hydrophilic zinc oxide surface, the hydrophilicity of zinc oxide can be further improved, so that zinc oxide can be more evenly and stably dispersed in the aqueous phase system. Azobisisobutyronitrile decomposes to generate free radicals after heating, which promotes the grafting reaction between 2-methacryloyloxyethyl phosphorylcholine monomer and the active sites on the hydrophilic zinc oxide surface, making the grafting reaction more efficient.

[0069] It can be seen from Examples 13-14 and Table 1 that adding all the modifiers at once will make the reaction system too viscous, affecting the modification effect. Adding them in batches can avoid this phenomenon.

[0070] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A method for preparing hydrophilic modified zinc oxide, characterized in that: The following steps are involved: 0.1-5 parts of a modifier by weight are dissolved in a solvent, the solution containing the modifier is evenly mixed with 20 parts of zinc oxide powder, and dried at 100-150° C. to obtain hydrophilic zinc oxide; the modifier includes polyglycerol.

2. The method for preparing the 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 the hydrophilic modified zinc oxide according to claim 1, characterized in that: The modifying agent also includes polyethylene glycol.

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

1.

6. The method for preparing the hydrophilic modified zinc oxide according to claim 1, characterized in that: The following steps are involved: Dissolve 0.1-5 parts of the modifier by weight in 20 parts of zinc oxide powder, mix well, and dry at 100-150° C. to obtain hydrophilic zinc oxide; The hydrophilic zinc oxide obtained in the above step is added to the 2-methacryloyloxyethyl phosphorylcholine solution, and the reaction time is 12-16 hours at 55-65° C. and a stirring speed of 200-500 r / min. After the reaction is completed, the solid product is separated by centrifugation, and washed and dried to obtain the hydrophilic zinc oxide grafted with phosphorylcholine.

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

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

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