Titanium dioxide-containing sun-screening agent, preparation method thereof and sun-screening product

Abstract

The invention relates to the field of chemical engineering, in particular to a sun-screening agent containing titanium dioxide, a preparation method of the sun-screening agent and a sun-screening product. The invention provides a preparation method of a titanium dioxide-containing sun-screening agent. The preparation method comprises the following steps: mixing micron-sized silicon dioxide powder and water, and heating to obtain slurry A; heating a titanium tetrachloride aqueous solution, adding the titanium tetrachloride aqueous solution into the slurry A, adding the titanium tetrachloride aqueous solution for a certain period of time, heating to a boiling state, and keeping the temperature after adding the titanium tetrachloride aqueous solution to obtain slurry B; and neutralizing the slurry B by using a neutralizer, and then carrying out post-treatment to obtain the sun-screening agent containing titanium dioxide. The micron-sized spherical silicon dioxide is used as a carrier, the superfine titanium dioxide is effectively loaded on the surface of the silicon dioxide carrier, and the superfine titanium dioxide is coated on the surface of the silicon dioxide carrier to form a complete shell layer, so that a high sunscreen index can be obtained and ideal transparency can be obtained when the superfine titanium dioxide is applied to sunscreen.

Description

TECHNICAL FIELD

[0001] The present application relates to the chemical industry, in particular to a sunscreen agent containing titanium dioxide and a preparation method thereof, and a sunscreen product. BACKGROUND

[0002] Ultrafine titanium dioxide (particle size of 100-200 nm) has good UV shielding performance due to its stable chemical properties, and can be used as a physical sunscreen in sunscreen cosmetics, especially in sunscreen products for children. Compared with nano titanium dioxide, ultrafine titanium dioxide has relatively low transparency when applied. The invention patent with application number CN201810335420.3 discloses a method for coating a titanium dioxide shell layer on the surface of silicon dioxide. Water glass solution and ammonia water are used as raw materials to obtain silicon dioxide sol, and then titanium sulfate oxide and sodium acetate are reacted to obtain titanium dioxide, which is coated on the surface of the silicon dioxide sol to form a titanium oxide shell layer. The obtained sample is suitable for use in the fields of coatings and plastics. However, due to the high impurity content of commercially available water glass solution and titanium sulfate oxide solution, the heavy metal element content of the product is difficult to meet the application requirements. In addition, high hiding power is one of the characteristics of the product. If used as a sunscreen agent, it cannot meet the requirement of high transparency due to excessive hiding power. SUMMARY

[0003] Therefore, the present application provides a sunscreen agent containing titanium dioxide and a preparation method thereof, and a sunscreen product. The sunscreen agent provided by the present application has excellent sunscreen index and transparency.

[0004] The present application provides a preparation method of a sunscreen agent containing titanium dioxide, comprising the following steps:

[0005] (A) mixing micron-sized silicon dioxide powder with water, heating to obtain slurry A;

[0006] (B) heating a titanium tetrachloride aqueous solution, then adding the slurry A, heating to boiling state after adding for a certain period of time, and keeping warm after the addition is completed to obtain slurry B;

[0007] (C) neutralizing the slurry B with a neutralizing agent, and then performing post-treatment to obtain the sunscreen agent containing titanium dioxide.

[0008] Preferably, in step (A), the heating temperature is 80-105℃.

[0009] Preferably, in step (A), the concentration of the slurry A is 15% (w / w) to 25% (w / w).

[0010] Preferably, in step (B):

[0011] The TiO2 concentration of the aqueous titanium tetrachloride solution is 200-310 g / L.

[0012] The heating temperature of the aqueous titanium tetrachloride solution is 20-85℃.

[0013] Preferably, in step (B), the aqueous titanium tetrachloride solution is added into the slurry A in a total feeding time of 120-300 min.

[0014] The mass ratio of TiO2 in the aqueous titanium tetrachloride solution to the silica in the slurry A is (0.4-1.0) : 1.

[0015] The total feeding time of the aqueous titanium tetrachloride solution is controlled in a range of 120-300 min.

[0016] The certain time is 10%-75% of the total feeding time.

[0017] The holding time is 30-300 min.

[0018] Preferably, in step (C), the end point pH value of the neutralization is 4.0-8.0.

[0019] Preferably, in step (C), the post-treatment preferably includes solid-liquid separation, washing and drying.

[0020] Preferably, in step (C), after the post-treatment, surface treatment can be further performed.

[0021] The surface treatment is surface coating treatment.

[0022] The surface coating treatment is organic surface treatment; the treatment agent used in the organic surface treatment is at least one of organosilicon and stearic acid.

[0023] The amount of the treatment agent used in the surface treatment is 1%-15% of the mass of the sample to be treated.

[0024] The present application also provides a sunscreen agent containing titanium dioxide prepared by the preparation method described in the above technical solution.

[0025] The present application also provides a sunscreen product, wherein the sunscreen agent comprises the sunscreen agent described in the above technical solution.

[0026] The application provides a preparation method of a sunscreen agent containing titanium dioxide, wherein micron-sized silica powder is mixed with water and heated to obtain slurry A; a titanium tetrachloride aqueous solution is heated and then added into the slurry A, the feeding is carried out for a certain time, then the temperature is raised to boiling state, and after the feeding is completed, the temperature is kept constant to obtain slurry B; the slurry B is neutralized by using a neutralizing agent, and then post-treated to obtain the sunscreen agent containing titanium dioxide. The micron-sized spherical silica is used as a carrier, and the superfine titanium dioxide is effectively loaded on the surface of the silica carrier, and the superfine titanium dioxide is coated on the surface to form a complete shell, so that a high sunscreen index and ideal transparency can be obtained when the sunscreen agent is applied.

[0027] The test results show that the sunscreen index of the product obtained by the application is above 5.2, and the transparency is above 70.5%, so that the product has high sunscreen effect and excellent transparency. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of the provided drawings.

[0029] Figure 1 The SEM image of the product obtained in Example 1 of the application. DETAILED DESCRIPTION

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0031] In the technical features described in an open manner herein, both a closed technical solution consisting of listed features and an open technical solution containing listed features are included.

[0032] The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0033] In this text, when referring to a numerical range, unless otherwise specified, the numerical range is considered to be continuous and includes the minimum and maximum values of the range and every value between such minimum and maximum values. Further, when the range refers to integers, every integer between the minimum and maximum values of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein are to be understood as including any and all sub-ranges subsumed therein.

[0034] In this text, when referring to a numerical range, unless otherwise specified, the numerical range is considered to be continuous and includes the minimum and maximum values of the range and every value between such minimum and maximum values. Further, when the range refers to integers, every integer between the minimum and maximum values of the range is included. In addition, when multiple ranges are provided to describe a feature or characteristic, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein are to be understood as including any and all sub-ranges subsumed therein.

[0035] In a first aspect, the present application provides a method for preparing a sunscreen agent containing titanium dioxide, comprising the following steps:

[0036] (A) mixing micron-sized silica powder with water and heating to obtain slurry A;

[0037] (B) adding the slurry A into the heated titanium tetrachloride aqueous solution, adding for a certain time, then heating to boiling state, and keeping after adding is finished to obtain slurry B;

[0038] (C) neutralizing the slurry B with a neutralizing agent, and then performing post-treatment to obtain the sunscreen agent containing titanium dioxide.

[0039] In the present application, the steps / operations in the above steps (A)-(C) have no sequence correlation, and the sequence has no special limitation.

[0040] Concerning step (A)

[0041] (A) mixing micron-sized silica powder with water and heating to obtain slurry A.

[0042] In the present application, the average particle size of the micron-sized silica powder is preferably 3-12 μm, and can be specifically 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, or 12 μm. The micron-sized silica powder has no special limitation and can be a commercially available product or prepared according to a known preparation method in the art.

[0043] In the present application, the water is preferably deionized water.

[0044] ​In the present application, the ratio of the use amount of the micron-sized silicon dioxide powder and water is preferably such that the concentration of the obtained slurry A (i.e. the silicon dioxide slurry) is 15% (w / w) to 25% (w / w), and specifically can be 15% (w / w), 16% (w / w), 17% (w / w), 18% (w / w), 18.5% (w / w), 19% (w / w), 20% (w / w), 21% (w / w), 22% (w / w), 23% (w / w), 24% (w / w), 25% (w / w), and more preferably 18.5% (w / w).

[0045] In the present application, the way of mixing the micron-sized silicon dioxide powder and water is not particularly limited, and any conventional mixing method can be used as long as the materials can be uniformly mixed, such as stirring.

[0046] In the present application, the temperature of heating is preferably 80 to 105°C (i.e. heating to 80 to 105°C), and specifically can be 80°C, 81°C, 82°C, 83°C, 84°C, 85°C, 86°C, 87°C, 88°C, 89°C, 90°C, 91°C, 92°C, 93°C, 94°C, 95°C, 96°C, 97°C, 98°C, 99°C, 100°C, 101°C, 102°C, 103°C, 104°C, 105°C.

[0047] Concerning step (B) :

[0048] (B) After heating the aqueous titanium tetrachloride solution, the slurry A is added, and after a certain time of feeding, the temperature is raised to boiling state, and after the feeding is completed, the temperature is maintained to obtain the slurry B.

[0049] In the present application, the aqueous titanium tetrachloride solution is an aqueous solution formed by dissolving titanium tetrachloride in water. The TiO2 concentration of the aqueous titanium tetrachloride solution is preferably 200 to 310 g / L, and specifically can be 200 g / L, 210 g / L, 220 g / L, 230 g / L, 240 g / L, 250 g / L, 260 g / L, 270 g / L, 280 g / L, 290 g / L, 300 g / L, 310 g / L, and more preferably 280 g / L.

[0050] In the present application, the temperature of heating the aqueous titanium tetrachloride solution is preferably 20 to 85°C (i.e. heating to 20 to 85°C), and specifically can be 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, and more preferably 80°C.

[0051] In the present application, the heated titanium tetrachloride aqueous solution is added to the slurry A. In the present application, the mass ratio of TiO2 in the titanium tetrachloride aqueous solution to the silicon dioxide in the slurry A is preferably (0.4-1.0):1, and can be specifically 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1.0:1.

[0052] In the present application, the total feeding time of the titanium tetrachloride aqueous solution is preferably controlled to be 120-300 min, and can be specifically 120 min, 150 min, 180 min, 210 min, 240 min, 270 min, 300 min, and more preferably 180 min. In the present application, the feeding process of the titanium tetrachloride aqueous solution is preferably uniform feeding.

[0053] In the present application, during the feeding of the heated titanium tetrachloride aqueous solution to the slurry A, the temperature is increased to boiling state after a certain time. The certain time is preferably 10%-75% of the total feeding time, and can be specifically 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, and more preferably 30%. After the temperature is increased to boiling state, the boiling state is maintained for subsequent operations.

[0054] In the present application, after the above-mentioned temperature increase to boiling state, or during the above-mentioned temperature increase to boiling state and after the temperature increase to boiling state, the feeding is continuously performed, and the holding is performed after the feeding is completed. The holding time is preferably 30-300 min, and can be specifically 30 min, 60 min, 90 min, 120 min, 150 min, 180 min, 210 min, 240 min, 270 min, 300 min, and more preferably 180 min. In the present application, after the above-mentioned holding, cooling is preferably performed. The cooling is preferably cooling to 30-60℃, and can be specifically 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, and more preferably cooling to 50℃.

[0055] Concerning step (C) :

[0056] (C) The slurry B is neutralized by using a neutralizing agent, and then subjected to post-treatment to obtain a sunscreen agent containing titanium dioxide.

[0057] In the present application, the neutralizing agent is preferably a basic substance, more preferably at least one of a sodium hydroxide solution, a potassium hydroxide solution, and ammonia water, and more preferably a sodium hydroxide solution. The sodium hydroxide solution is preferably an aqueous sodium hydroxide solution. The potassium hydroxide solution is preferably an aqueous potassium hydroxide solution. The end point pH value of the neutralization is preferably 4.0-8.0, and more preferably 4.8.

[0058] In the present application, after the above neutralization, post-treatment is performed. The post-treatment preferably includes solid-liquid separation, washing, and drying. The solid-liquid separation method is not particularly limited, and can be a conventional solid-liquid separation method, such as filtration. The washing agent is preferably water, and more preferably deionized water. The drying temperature is preferably 90-105°C, and more preferably 90°C, 95°C, 100°C, or 105°C. After drying, a solid product is obtained. The product has a core-shell structure, with micron-sized spherical silica as the carrier and ultrafine titanium dioxide coated on the surface to form a shell layer.

[0059] In the present application, after the above post-treatment, surface treatment can also be performed. The surface treatment is preferably surface coating treatment. The surface coating treatment is preferably organic surface treatment. In the present application, the treatment agent used in the organic surface treatment is preferably at least one of silicone and stearic acid. The amount of the treatment agent used in the surface treatment is preferably 1%-15% of the mass of the sample to be treated, and more preferably 1%, 5%, 10%, or 15%. The surface treatment can be wet organic surface treatment or dry organic surface treatment, and the process is not particularly limited, and can be performed according to known treatment methods in the art. After the above treatment, a product is obtained.

[0060] In a second aspect, the present application also provides a sunscreen agent containing titanium dioxide prepared by the preparation method described in the above technical solution.

[0061] In a third aspect, the present application also provides a sunscreen product, wherein the sunscreen agent comprises the sunscreen agent described in the above technical solution.

[0062] The application provides a preparation method of a sunscreen agent containing titanium dioxide, wherein micron-sized silicon dioxide powder is mixed with water and heated to obtain slurry A; a titanium tetrachloride aqueous solution is heated and then added into the slurry A, the feeding is continued until the reaction material is heated to boiling and kept in boiling state, and then the feeding is stopped, and the slurry B is obtained after heat preservation; the slurry B is neutralized by using a neutralizing agent, and then post-treated to obtain the sunscreen agent containing titanium dioxide. The micron-sized spherical silicon dioxide is used as a carrier, and the superfine titanium dioxide is effectively loaded on the surface of the silicon dioxide carrier, and the superfine titanium dioxide is coated on the surface to form a complete shell, so that a high sunscreen index and ideal transparency can be obtained when the sunscreen agent is applied.

[0063] The test results show that the sunscreen index of the product obtained by the application is above 5.2, and the transparency is above 70.5%, so that the product has high sunscreen effect and excellent transparency.

[0064] In order to further understand the application, the preferred embodiments of the application are described below in combination with examples, but it should be understood that the description is only for further illustrating the features and advantages of the application, and is not a limitation on the claims of the application.

[0065] Example 1

[0066] S1, micron-sized silicon dioxide powder (average particle size 3 μm) is mixed with deionized water, stirred for 30 min, and then heated to 95 ℃ to obtain slurry A with a mass concentration of 18.5%.

[0067] S2, a titanium tetrachloride aqueous solution with a TiO2 concentration of 285 g / L and a temperature of 80 ℃ is uniformly added into the slurry A, the mass ratio of TiO2 in the titanium tetrachloride aqueous solution to silicon dioxide in the slurry A is 0.4:1, the reaction material is heated to boiling when the feeding time reaches 50 min and kept in boiling state, then the feeding is continued, the feeding is stopped after the total feeding time of 180 min, and then the slurry B is obtained after heat preservation for 180 min and cooling to 50 ℃.

[0068] S3, the slurry B is neutralized to a pH value of 4.8 by using a sodium hydroxide aqueous solution, and then filtered, washed and dried to obtain the product.

[0069] The SEM image of the obtained product is shown in Figure 1 As can be seen, the obtained product is a relatively uniform spherical particle with a relatively complete coating layer on the surface.

[0070] Example 2

[0071] S1, micron-sized silicon dioxide powder (average particle size 8 μm) is mixed with deionized water, stirred for 30 min, and then heated to 95 ℃ to obtain slurry A with a mass concentration of 18.5%.

[0072] S2, the TiO2 concentration of 285 g / L, 80 ℃ titanium tetrachloride aqueous solution uniform speed into the slurry A, the use of titanium tetrachloride aqueous solution in the mass ratio of TiO2 in the slurry A of 0.7:1, the feeding time to reach 50 min heating reaction material to boiling and keep boiling state, then continue to feed, after feeding (the total feeding time is 180 min) 180 min, then cooled to 50 ℃, get slurry B.

[0073] S3, using sodium hydroxide solution to slurry B neutralization to pH value of 4.8, then, filter, wash and dry, get product.

[0074] Example 3

[0075] S1, micron grade silica powder (average particle size of 12 μm) and deionized water mixed, heated to 95 ℃ after stirring 30 min, get mass concentration of 18.5% slurry A.

[0076] S2, the TiO2 concentration of 285 g / L, 80 ℃ titanium tetrachloride aqueous solution uniform speed into the slurry A, the use of titanium tetrachloride aqueous solution in the mass ratio of TiO2 in the slurry A of 1.0:1, the feeding time to reach 50 min heating reaction material to boiling and keep boiling state, then continue to feed, after feeding (the total feeding time is 180 min) 180 min, then cooled to 50 ℃, get slurry B.

[0077] S3, using sodium hydroxide solution to slurry B neutralization to pH value of 4.8, then, filter, wash and dry, get product.

[0078] Example 4

[0079] S1, micron grade silica powder (average particle size of 8 μm) and deionized water mixed, heated to 95 ℃ after stirring 30 min, get mass concentration of 18.5% slurry A.

[0080] S2, the TiO2 concentration of 285 g / L, 80 ℃ titanium tetrachloride aqueous solution uniform speed into the slurry A, the use of titanium tetrachloride aqueous solution in the mass ratio of TiO2 in the slurry A of 0.7:1, the feeding time to reach 50 min heating reaction material to boiling and keep boiling state, then continue to feed, after feeding (the total feeding time is 180 min) 180 min, then cooled to 50 ℃, get slurry B.

[0081] S3, the slurry B is neutralized to pH 4.8 by using sodium hydroxide aqueous solution, then filtered, washed and dried to obtain a solid sample. After crushing, the product is obtained by using 5% of the mass of the powder of organic silicon for surface treatment.

[0082] Example 5

[0083] S1, micron-sized silica powder (average particle size 8 μm) is mixed with deionized water, heated to 82°C after stirring for 30 min to obtain a slurry A with a mass concentration of 15.0%.

[0084] S2, a titanium tetrachloride aqueous solution with a TiO2 concentration of 310 g / L and a temperature of 85°C is added uniformly to the slurry A, the mass ratio of TiO2 in the titanium tetrachloride aqueous solution to the silica in the slurry A is 0.6:1, the reaction material is heated to boiling and kept in boiling state when the feeding time reaches 80 min, then the feeding is continued, after the feeding is completed (the total feeding time is 240 min), the heat preservation is carried out for 60 min, and then the temperature is cooled to 60°C to obtain the slurry B.

[0085] S3, the slurry B is neutralized to pH 6.5 by using sodium hydroxide aqueous solution, then filtered, washed and dried to obtain the product.

[0086] Example 6

[0087] S1, micron-sized silica powder (average particle size 8 μm) is mixed with deionized water, heated to 102°C after stirring for 30 min to obtain a slurry A with a mass concentration of 25%.

[0088] S2, a titanium tetrachloride aqueous solution with a TiO2 concentration of 285 g / L and a temperature of 30°C is added uniformly to the slurry A, the mass ratio of TiO2 in the titanium tetrachloride aqueous solution to the silica in the slurry A is 0.8:1, the reaction material is heated to boiling and kept in boiling state when the feeding time reaches 50 min, then the feeding is continued, after the feeding is completed (the total feeding time is 180 min), the heat preservation is carried out for 120 min, and then the temperature is cooled to 45°C to obtain the slurry B.

[0089] S3, the slurry B is neutralized to pH 7.0 by using sodium hydroxide aqueous solution, then filtered, washed and dried to obtain the product.

[0090] Example 7

[0091] S1, micron-sized silica powder (average particle size 5 μm) is mixed with deionized water, heated to 95°C after stirring for 30 min to obtain a slurry A with a mass concentration of 20%.

[0092] S2, the TiO2 concentration of 285 g / L, the temperature of 60℃ titanium tetrachloride aqueous solution is added to the slurry A at a constant speed, the mass ratio of TiO2 in the titanium tetrachloride aqueous solution to the silicon dioxide in the slurry A is 0.5:1, when the feeding time reaches 1500 min, the reactant is heated to boiling and kept in boiling state, then the feeding is continued, after the feeding is completed (the total feeding time is 300 min), the heat preservation is carried out for 60 min, and then the temperature is cooled to 55℃, to obtain the slurry B.

[0093] S3, the slurry B is neutralized to pH 7.0 by using sodium hydroxide aqueous solution, then filtered, washed and dried to obtain the product.

[0094] Comparative Example 1

[0095] The product is prepared by using the technical solution in the embodiment 1 disclosed in CN108570248A.

[0096] Effect test

[0097] The samples are dispersed in dimethyl silicone oil 10CS to prepare sample solutions with a solid content of 15%. Then, the sunscreen index and transparency tests are carried out. The products obtained in each example and comparative example are subjected to the above tests. The results are shown in Table 1.

[0098] Table 1: Test results

[0099] Sun protection factor SPF Transparency (%) Example 1 5.2 78.8 Example 2 10.0 75.7 Example 3 15.5 70.5 Example 4 10.5 75.4 Example 5 8.5 72.3 Example 6 6.8 74.6 Example 7 5.8 76.8 Comparative example 1 1.1 34.5

[0100] As can be seen from the test results in the above table, the sunscreen index of the product obtained in the present application is above 5.2, and the transparency is above 70.5%, which has high sunscreen effect and excellent transparency. Compared with Example 1, the sunscreen index and transparency of Comparative Example 1 are both poor, which proves that the titanium dioxide coated silicon dioxide product prepared by the specific method of the present application can effectively improve the sunscreen effect and transparency.

[0101] ​The principles and implementations of the present application are described herein with specific examples, and the above descriptions of the examples are only used to help understand the method of the present application and its core ideas, including the best mode, and also enable any person skilled in the art to practice the present application, including manufacturing and using any device or system, and implementing any combined method. It should be noted that, for those skilled in the art, some improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application. The scope of patent protection of the present application is defined by the claims, and can include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements similar to the literal expressions of the claims, or if they include equivalent structural elements that are not substantially different from the literal expressions of the claims, then these other embodiments should also be included within the scope of the claims.

Claims

1. A method for preparing a sunscreen containing titanium dioxide, characterized in that, Includes the following steps: (A) Micron-sized silica powder is mixed with water and heated to obtain slurry A; (B) After heating the titanium tetrachloride aqueous solution, add it to the slurry A. After adding the material for a certain period of time, raise the temperature to the boiling state. After the addition is completed, keep the temperature to obtain slurry B. (C) Neutralize the slurry B with a neutralizing agent, and then perform post-treatment to obtain a sunscreen containing titanium dioxide.

2. The preparation method according to claim 1, characterized in that, In step (A), the heating temperature is 80–105°C.

3. The preparation method according to claim 1, characterized in that, In step (A), the concentration of slurry A is 15% (w / w) to 25% (w / w).

4. The preparation method according to claim 1, characterized in that, In step (B): The TiO2 concentration of the titanium tetrachloride aqueous solution is 200–310 g / L; The titanium tetrachloride aqueous solution is heated to a temperature of 20–85°C.

5. The preparation method according to claim 1, characterized in that, In step (B): The mass ratio of TiO2 in the titanium tetrachloride aqueous solution to silicon dioxide in the slurry A is (0.4-1.0):1; The total feeding time of the titanium tetrachloride aqueous solution is controlled between 120 and 300 minutes. The specified time is 10% to 75% of the total feeding time; The heat preservation time is 30 to 300 minutes.

6. The preparation method according to claim 1, characterized in that, In step (C), the endpoint pH value of the neutralization is 4.0 to 8.

0.

7. The preparation method according to claim 1, characterized in that, In step (C), the post-processing preferably includes: solid-liquid separation, washing, and drying.

8. The preparation method according to claim 1, characterized in that, In step (C), after the post-processing, surface treatment may also be performed; The surface treatment is a surface coating treatment; The surface coating treatment is an organic surface treatment; the treatment agent used in the organic surface treatment is at least one of organosilicon and stearic acid; The amount of the treatment agent used in the surface treatment is 1% to 15% of the mass of the sample to be treated.

9. A sunscreen containing titanium dioxide prepared by any one of claims 1 to 8.

10. A sunscreen product, characterized in that, The sunscreen agent included in claim 9 is the sunscreen agent described in claim 9.

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