Toothpaste capable of displaying dental plaque and preparation method thereof

Abstract

The invention provides a toothpaste capable of displaying dental plaque, wherein the raw materials include: 0.1-0.5 parts by weight of menthol, 30-68 parts by weight of humectant, 13-30 parts by weight of solvent, 0.1-1 parts by weight of thickener, 5-12 parts by weight of developer, 2-15 parts by weight of functional component, 2-5 parts by weight of foaming agent and 10-25 parts by weight of abrasive. The toothpaste is modified and attached to erythrosine, thereby ensuring the color development effect of erythrosine and reducing the adhesion of erythrosine on lips and oral cavity inner membrane, and can be erased by gargling or gently pressing with a tissue.

Description

Technical Field

[0001] The invention belongs to the technical field of oral care, and in particular relates to a toothpaste capable of displaying dental plaque and a preparation method thereof. Background Art

[0002] Currently, the toothpaste on the market has the function of cleaning the oral cavity, or the functional toothpaste only has its functional function; after brushing teeth, it cannot show the degree of plaque cleaning. Guangzhou Weimeizi Industrial Co., Ltd. applied for a patent application for plaque coloring toothpaste in 2017, patent number: 201710169393.2, which can help show the areas that are not clean enough after brushing teeth. Continue to use toothpaste to show the areas with plaque until they are clean and free of plaque. If there is still residual plaque after brushing teeth with toothpaste several times, you should see a doctor in severe cases.

[0003] According to consumer feedback, existing color developers have strong adhesion. Erythrosine is one of the most commonly used types of red color developers. Its characteristics are: Erythrosine is a reddish-brown granular or powdery substance, odorless, easily soluble in water, and its aqueous solution is red. It has good tolerance to oxygen, heat, and redox agents, and has strong dyeing power, but poor acid and light resistance, poor hygroscopicity, and forms an insoluble yellow-brown precipitate under the condition of pH <4.5, and produces a red precipitate when alkaline. It is not easily absorbed in the digestive tract, and even if it is absorbed, it does not participate in metabolism, so it is considered to be a synthetic pigment with higher safety. It is mainly used in beverages, mixed wines, candies, baked goods, etc. However, the most obvious disadvantage of using erythrosine in toothpaste or food is that it is easy to stain the mouth, and it is difficult to remove the color, and it may even take 24-72 hours to completely disappear. Especially for children, it is like painting the lips, which affects children's willingness to use it. The principle of the color developer is to color the protein. The oral lining, lips, gums, etc. all contain protein. It is a normal reaction to come into contact with the color developer to develop color. In view of the problem of strong adhesion of the color developer, the present invention professionally processes the color developer, which improves the color development effect while reducing the adhesion. It can not only develop color instantly, but also quickly and easily remove the color of soft tissue. Summary of the invention

[0004] The purpose of the present invention is to provide a toothpaste that can display dental plaque and quickly remove the color in soft tissue in order to solve the problem that the color developer in the prior art is difficult to remove in soft tissue.

[0005] To achieve the above purpose, the specific plan is as follows: a toothpaste that can display dental plaque, the raw materials include: 0.1-0.5 weight parts of menthol, 30-68 weight parts of moisturizer, 13-30 weight parts of solvent, 0.1-1 weight parts of thickener, 5-12 weight parts of developer, 2-15 weight parts of functional ingredients, 2-5 weight parts of foaming agent and 10-25 weight parts of abrasive.

[0006] The present invention is further preferred that the developer is an adhesive erythrosine, and its preparation method is as follows: 1) weighing 0.1-2 parts by weight of erythrosine; 2) weighing 10-30 parts by weight of calcium chloride or calcium sulfate, adding to deionized water, to obtain a solution with a calcium ion concentration of 0.01-0.02 mol / L and a pH of 5-7; 3) dripping 3-5 mol / L sodium bicarbonate solution into the solution prepared in step 2), adjusting the pH to 8.5-9, precipitating, maintaining greater than 8.5 until no more precipitates are precipitated, filtering to obtain a wet precipitate; 4) adding erythrosine to the wet precipitate prepared in step 3, mixing evenly, promoting the modified adhesion of erythrosine under the conditions of infrared addition and ultraviolet radiation, to obtain adhesive erythrosine.

[0007] In the present invention, the infrared temperature is 75-95° C., the ultraviolet intensity of 50-100 nm wavelength is 2000LEX, and the treatment time is 12-18 min.

[0008] In the present invention, the humectant is further preferably sorbitol.

[0009] In the present invention, the solvent is preferably ethanol and boiling water, and the weight ratio of ethanol to boiling water is 2-5:1.

[0010] In the present invention, the thickener is further preferably xanthan gum and carboxymethyl cellulose, and the weight ratio of xanthan gum to carboxymethyl cellulose is 1:3-8.

[0011] It is further preferred that the functional ingredient is the anti-allergic bioactive glass powder produced by the applicant, which has been granted an invention patent on December 29, 2020.

[0012] In the present invention, the foaming agent is further preferably CAB-35 and sodium lauryl sulfate, and the weight ratio is 1:1-2.

[0013] Further preferably, the present invention further comprises 0.1-1 parts by weight of a sweetener, wherein the sweetener is xylitol or saccharin sodium.

[0014] Further preferably, the present invention further comprises 0.1-1 parts by weight of a sweetener, wherein the sweetener is erythritol.

[0015] The present invention is further preferred that the friction agent hydrated silica, the preparation method of the hydrated silica is: 1) adding sodium silicate solid with a modulus of 1.5-2 to deionized water, heating to 80-120°C, and preparing a sodium silicate solution with a concentration of 4-6 mol / L; 2) preparing a sulfuric acid solution with a concentration of 5-6 mol / L; 3) adding sodium dodecyl sulfonate solution to the reactor, heating to 80-90°C, and dropping sodium silicate solution and sulfuric acid solution while stirring, the volume ratio of sodium silicate solution to sulfuric acid solution and sodium dodecyl sulfonate solution is 2:3-5:1, after the sodium silicate solution is added, the reaction temperature is controlled to 80-95°C, and sulfuric acid solution is continued to be added until the pH value in the reaction system is 3.5-5.5, stirring is continued and standing, and suction filtering is performed; 4) the filtered soil is rinsed with cooling water to obtain silica slurry, and the obtained silica slurry is spray-dried to obtain hydrated silica.

[0016] The present invention is further preferably added with a fragrance agent, agarwood essential oil, which increases the color development rate of erythrosine and reduces its adhesion, in an amount of 0.2-0.6 parts by weight.

[0017] In the present invention, the raw material further comprises 0.01-0.1 parts by weight of a preservative, wherein the preservative is ethyl p-hydroxybenzoate and propyl p-hydroxybenzoate.

[0018] Further preferably, the preparation method of the agarwood essential oil is: using corn oil to soak and extract dried agarwood seeds, and then separating to obtain the agarwood essential oil containing corn oil impurities.

[0019] Another object of the present invention is to provide a method for preparing a toothpaste capable of showing dental plaque, the specific steps of which are:

[0020] 1) Agarwood essential oil and menthol are mixed and added to the developer adhesive erythrosine, and mixed evenly to obtain a color-developing mixture; 2) Sorbitol, a thickener, a solvent ethanol, and boiling water are weighed and placed in a beaker, stirred and mixed evenly, and allowed to stand for more than 12 hours to allow the xanthan gum to soak and soften, and continued to stir until it is completely dissolved into an auxiliary agent solution; 3) The preservative and the color-developing mixture prepared in step 1 are weighed, added to the auxiliary agent solution prepared in step 2), and mixed evenly; 4) Functional ingredients, a foaming agent, and a sweetener are weighed, added to the mixture prepared in step 3), and mixed thoroughly to obtain a prefabricated paste; 5) Hydrated silicon dioxide is weighed, added to the prefabricated paste prepared in step 4), and stirred and mixed evenly until there are no particles and bubbles, and a toothpaste that can display dental plaque is obtained.

[0021] The difference from the prior art is that the present invention achieves the following technical effects:

[0022] 1) The invention ensures the color development effect of erythrosine by attaching erythrosine, while reducing the adhesion of erythrosine on lips and oral cavity inner membrane, and can be wiped off by rinsing the mouth or lightly pressing with a tissue.

[0023] 2) The present invention has found through experiments that trace amounts of agarwood essential oil can improve the color development time and color development effect of erythrosine.

[0024] 3) The adhesive erythrosine prepared by the present invention ensures that the pH environment of the erythrosine is stable, and no yellowing precipitation or red precipitation occurs in the toothpaste, which causes the toothpaste to lose its color development function.

[0025] 4) The present invention can improve the cleaning performance of toothpaste by adding specially prepared hydrated silicon dioxide.

[0026] 5) If erythritol is used as the sweetener of the present invention, it can not only ensure the sweetness of the toothpaste, but also improve the color change efficiency of erythrosine, and when matched with agarwood essential oil, the color development effect of erythrosine is improved. DETAILED DESCRIPTION

[0027] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Part I:

[0029] Preparation of adhesive erythrosine: 1) weighing 0.1-2 parts by weight of erythrosine; 2) weighing 10-30 parts by weight of calcium chloride or calcium sulfate, adding into deionized water, obtaining a solution with a calcium ion concentration of 0.01-0.02 mol / L and a pH of 5-7; 3) dripping 3-5 mol / L sodium bicarbonate solution into the solution prepared in step 2), adjusting the pH to 8.5-9, causing precipitation, maintaining the pH to be greater than 8.5 until no more precipitation is precipitated, filtering to obtain a wet precipitate; 4) adding erythrosine into the wet precipitate prepared in step 3, mixing evenly, promoting the modified adhesion of erythrosine under the conditions of adding infrared rays and irradiating ultraviolet rays, obtaining adhesive erythrosine.

[0030] Preparation of hydrated silicon dioxide: 1) adding sodium silicate solid with a modulus of 1.5-2 into deionized water, heating to 80-120°C, and preparing a sodium silicate solution with a concentration of 4-6 mol / L; 2) preparing a sulfuric acid solution with a concentration of 5-6 mol / L; 3) adding sodium dodecyl sulfonate solution into a reaction kettle, heating to 80-90°C, and dripping sodium silicate solution and sulfuric acid solution while stirring, wherein the volume ratio of sodium silicate solution to sulfuric acid solution and sodium dodecyl sulfonate solution is 2:3-5:1, and after the sodium silicate solution is dripped, the reaction temperature is controlled to be 80-95°C, and sulfuric acid solution is continuously dripped until the pH value in the reaction system is 3.5-5.5, stirring is continued, standing is continued, and suction filtering is performed; 4) washing the filtered soil with cooling water to obtain silicon dioxide slurry, and the obtained silicon dioxide slurry is spray-dried to obtain hydrated silicon dioxide.

[0031] Embodiment 1:

[0032] Weigh the following raw materials:

[0033] Menthol 0.1kg; sorbitol 30kg; ethanol 12kg, boiling water 3kg; xanthan gum 0.04kg and carboxymethyl cellulose 0.16kg; anti-allergic bioactive glass powder 5kg, CAB-35 1kg, sodium lauryl sulfate 1kg, hydrated silicon dioxide 20kg.

[0034] Preparation of toothpaste: 1) adding menthol to the color developer adhesive erythrosine, mixing evenly to obtain a color development mixture; 2) weighing sorbitol, a thickener, a solvent ethanol, and boiling water, placing them in a beaker, stirring and mixing evenly, letting them stand for more than 12 hours to allow the xanthan gum to soak and soften, and continuing to stir until it is completely dissolved into an auxiliary agent solution; 3) weighing the preservative and the color development mixture prepared in step 1, adding them to the auxiliary agent solution prepared in step 2), and mixing evenly; 4) weighing anti-allergic bioactive glass powder and a foaming agent, adding them to the mixture prepared in step 3), mixing them thoroughly, and obtaining a prefabricated paste; 5) weighing hydrated silicon dioxide, adding it to the prefabricated paste prepared in step 4), stirring and mixing until there are no particles and bubbles, and obtaining the toothpaste that can display dental plaque of Example 1.

[0035] The formula of Examples 2-6 is shown in Table 1 below:

[0036]

[0037] The preparation method is similar to that of Example 1.

[0038] After coating tests on bacterial plaques and actual tests on volunteers, the toothpastes of Examples 1-6 were found to take about 5 seconds to develop color, which was slow. The volunteers had average reactions after use, and the staining of the lips and oral lining was easy to remove, and could be wiped off with a light wipe on the lips.

[0039] Part II:

[0040] Compared with Examples 1-6 in the first part, agarwood essential oil is added to the raw materials of Examples 7-12. The preparation method is referred to in Examples 1-6. The specific formula is as shown in Table 2 below:

[0041]

[0042] The preparation method comprises the following steps: 1) mixing agarwood essential oil and menthol, adding the mixture to the color developer adhesive erythrosine, and mixing evenly to obtain a color development mixture; 2) weighing sorbitol, a thickener, a solvent ethanol, and boiling water, placing them in a beaker, stirring and mixing evenly, standing for more than 12 hours to allow the xanthan gum to be soaked and softened, and continuing to stir until it is completely dissolved into an auxiliary agent solution; 3) weighing a preservative and the color development mixture prepared in step 1, adding them to the auxiliary agent solution prepared in step 2), and mixing evenly; 4) weighing a functional component and a foaming agent, adding them to the mixture prepared in step 3), and mixing them well to obtain a prefabricated paste; 5) weighing hydrated silicon dioxide, adding it to the prefabricated paste prepared in step 4), stirring and mixing until there are no particles and no bubbles, and obtaining the toothpaste capable of displaying dental plaque of embodiments 7-12.

[0043] Through the coating test on the plaque of Examples 7-12 and the actual test of volunteers, it was found that the color development time was between 3-4s, the color development speed was fast, the volunteers responded well after use, and the staining of the lips and oral lining was easy to remove, and the staining on the lips could be wiped off with a light wipe.

[0044] Part III:

[0045] Compared with Examples 1-6 in the first part, the raw materials of Examples 13-18 are added with sweetener erythritol, and the specific formula is as shown in Table 3 below:

[0046]

[0047] The preparation method comprises the following steps: 1) adding menthol to the color developer adhesive erythrosine, mixing uniformly, and obtaining a color development mixture; 2) weighing sorbitol, a thickener, a solvent ethanol, and boiling water, placing them in a beaker, stirring and mixing uniformly, standing for more than 12 hours to allow the xanthan gum to be soaked and softened, and continuing to stir until it is completely dissolved into an auxiliary agent solution; 3) weighing a preservative and the color development mixture prepared in step 1, adding them to the auxiliary agent solution prepared in step 2), and mixing uniformly; 4) weighing a functional component, a foaming agent, and a sweetener, adding them to the mixture prepared in step 3), mixing them fully, and obtaining a prefabricated paste; 5) weighing hydrated silicon dioxide, adding it to the prefabricated paste prepared in step 4), stirring and mixing uniformly until there are no particles and no bubbles, and obtaining the toothpaste capable of displaying dental plaque of embodiments 13-18.

[0048] After coating tests on plaques and actual tests by volunteers, it was found that the color development time was between 4-6s, the color development speed was normal, volunteers reported that the product was acceptable, and the staining of the lips and oral lining was easy to remove, just wipe it off on the lips, and children generally preferred this flavor.

[0049] Part 4:

[0050] Compared with Examples 1-6 in the first part, the raw materials of Examples 19-24 are increased with agarwood essential oil and sweetener erythritol, and the specific formula is as shown in Table 4 below:

[0051]

[0052] The preparation method comprises the following steps: 1) mixing agarwood essential oil and menthol, adding the mixture to the developer adhesive erythrosine, and mixing evenly to obtain a color development mixture; 2) weighing sorbitol, a thickener, a solvent ethanol, and boiling water, placing them in a beaker, stirring and mixing evenly, standing for more than 12 hours to allow the xanthan gum to soak and soften, and continuing to stir until it is completely dissolved into an auxiliary agent solution; 3) weighing a preservative and the color development mixture prepared in step 1, adding them to the auxiliary agent solution prepared in step 2), and mixing evenly; 4) weighing a functional component, a foaming agent, and a sweetener, adding them to the mixture prepared in step 3), and mixing them well to obtain a prefabricated paste;

[0053] 5) Weigh hydrated silicon dioxide, add it to the prefabricated paste prepared in step 4), stir and mix until there are no particles and bubbles, and obtain the toothpaste capable of revealing dental plaque of Examples 19-24.

[0054] After the toothpaste of Examples 19-24 was applied to the plaque for coating test and the actual test by volunteers, it was found that the color development time was less than 1 second, the color development speed was extremely fast, the reaction was good, and the staining of the lips and the inner membrane of the mouth was easy to remove, and it could be wiped off with a light wipe on the lips. The volunteer children preferred this kind of taste.

[0055] Part V:

[0056] The formula of Comparative Example 1 refers to Example 1. Compared with Example 1, the specially prepared attached erythrosine of the present invention is not used, but ordinary erythrosine is used. The preparation method refers to Example 1.

[0057] The formula of Comparative Example 2 refers to Example 7. Compared with Example 7, the specially prepared attached erythrosine of the present invention is not used, but ordinary erythrosine is used. The preparation method refers to Example 7.

[0058] The formula of Comparative Example 3 refers to Example 13. Compared with Example 13, the specially prepared attached erythrosine of the present invention is not used, but ordinary erythrosine is used. The preparation method refers to Example 13.

[0059] The formula of Comparative Example 4 refers to Example 19. Compared with Example 19, the specially prepared attached erythrosine of the present invention is not used, but ordinary erythrosine is used, and the preparation method refers to Example 19.

[0060] The toothpastes prepared in Examples 1-19 and the toothpastes prepared in Comparative Examples 1-4 were tested, and the test performances included the following:

[0061]

[0062]

[0063] Through the test results of the above implementation methods, it was found that the key to the present invention lies in the preparation step of attaching erythrosine, as well as the addition of agarwood essential oil and sweetener erythritol, which have made important contributions to the purpose of the invention and played a key role in the performance of the toothpaste.

[0064] By comparing Comparative Example 4 with other embodiments, it is found that hydrated silicon dioxide improves the cleaning performance of toothpaste on dental plaque.

[0065] Comparative Example 5: The formulation is prepared according to Example 19.

[0066] 1) agarwood essential oil, menthol, developer adhesive erythrosine, sorbitol, thickener, solvent ethanol & boiling water, preservative, functional ingredient, foaming agent, sweetener are placed in a container and mixed evenly to obtain mixture A; 2) weighed and placed in a beaker, stirred and mixed evenly, left to stand for more than 12 hours to allow xanthan gum to soak and soften, and continued to stir until it is completely dissolved to form an auxiliary agent solution; 3) mixture A is added to the auxiliary agent solution prepared in step 2) and mixed evenly; 4) hydrated silicon dioxide is weighed and added to the mixture prepared in step 3), stirred and mixed evenly until there are no particles and bubbles, to obtain the toothpaste of comparative example 5.

[0067] Comparative Example 6: The formulation is prepared according to Example 20.

[0068] Agarwood essential oil, menthol, color developer adhesive erythrosine, sorbitol, thickener, solvent ethanol & boiling water, preservatives, functional ingredients, foaming agent, sweetener, and silicon dioxide are placed in a container and mixed evenly to obtain mixture B; 2) weigh and place in a beaker, stir and mix, let stand for more than 12 hours to allow the xanthan gum to soak and soften, and continue stirring until it is completely dissolved to form an auxiliary agent solution; 3) Add mixture B to the auxiliary agent solution prepared in step 2), mix evenly, stir and mix until there are no particles or bubbles, and obtain the toothpaste of comparative example 6.

[0069] The toothpastes of Comparative Examples 5 and 6 had extremely poor color development effects, uneven distribution, unclear color development of dental plaque, and precipitation and agglomeration phenomena were observed after being placed in a 75° C. environment for less than 12 hours.

[0070] Through the test of comparative examples 5 and 6, it can be seen that the preparation method of the toothpaste in the present invention also plays a crucial role in the various properties of the toothpaste.

[0071] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Without departing from the principles of the present invention, any modification, equivalent replacement, improvement, and embellishment made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A toothpaste capable of showing dental plaque, the raw materials comprising: 0.1-0.5 parts by weight of menthol, 30-68 parts by weight of moisturizing agent, 13-30 parts by weight of solvent, 0.1-1 parts by weight of thickener, 5-12 parts by weight of developer, 2-15 parts by weight of functional ingredient, 2-5 parts by weight of foaming agent and 10-25 parts by weight of friction agent; also including 0.2-0.6 parts by weight of agarwood essential oil, 0.1-1 parts by weight of sweetener and 0.01-0.1 parts by weight of preservative, wherein the sweetener is xylitol or saccharin sodium or erythritol; the moisturizing agent is sorbitol; the thickener is xanthan gum and carboxymethyl cellulose; the developer is adhesive erythrosine; the abrasive is hydrated silicon dioxide, and the preservatives are ethyl p-hydroxybenzoate and propyl p-hydroxybenzoate; the preparation method is: 1) weighing 0.1-2 parts by weight of erythrosine; 2) weighing 10-30 parts by weight of calcium chloride or calcium sulfate, adding it to deionized water to obtain a calcium ion concentration of 0.01-0.02 mol / L A solution with a pH of 5-7; 3) dropping 3-5 mol / L sodium bicarbonate solution into the solution prepared in step 2), adjusting the pH to 8.5-9, precipitating, maintaining the pH to be greater than 8.5 until no more precipitates are precipitated, filtering to obtain a wet precipitate; 4) adding erythrosine to the wet precipitate prepared in step 3, mixing evenly, promoting the modified adhesion of erythrosine under the conditions of infrared addition and ultraviolet radiation, and obtaining an adhesive erythrosine; a toothpaste capable of displaying dental plaque, and a preparation method thereof, comprising the following specific steps: 1) mixing agarwood essential oil and menthol, and adding the mixture to the developer adhesive erythrosine, mixing evenly, and obtaining color mixture; 2) weigh sorbitol, thickener and solvent ethanol, boiling water into a beaker, stir and mix, let stand for more than 12 hours to allow the xanthan gum to soak and soften, and continue stirring until it is completely dissolved into an auxiliary agent solution; 3) weigh the preservative and the color mixture prepared in step 1, add them to the auxiliary agent solution prepared in step 2), and mix evenly; 4) weigh the functional ingredients, foaming agent and sweetener, add them to the mixture prepared in step 3), mix well, and obtain a prefabricated paste; 5) weigh hydrated silicon dioxide, add it to the prefabricated paste prepared in step 4), stir and mix until there are no particles and bubbles, and obtain a toothpaste that can display dental plaque.

2. The toothpaste capable of displaying dental plaque according to claim 1, characterized in that: The infrared temperature is 75-95° C., the ultraviolet intensity of 50-100 nm wavelength is 2000LEX, and the treatment time is 12-18 minutes.

3. The toothpaste capable of displaying dental plaque according to claim 1, characterized in that: The solvents are ethanol and boiling water, and the weight ratio of ethanol to boiling water is 2-5:

1.

4. The toothpaste capable of displaying dental plaque according to claim 1, characterized in that: The weight ratio of xanthan gum to carboxymethyl cellulose is 1:3-8.

5. The toothpaste capable of displaying dental plaque according to claim 1, characterized in that: The foaming agent is CAB-35 and sodium lauryl sulfate, and the weight ratio is 1:1-2.

6. The toothpaste capable of displaying dental plaque according to claim 1, characterized in that: The friction agent is hydrated silicon dioxide, and the preparation method of the hydrated silicon dioxide is as follows: 1) adding sodium silicate solid with a modulus of 1.5-2 into deionized water, heating to 80-120°C, and preparing a sodium silicate solution with a concentration of 4-6 mol / L; 2) preparing a sulfuric acid solution with a concentration of 5-6 mol / L; 3) adding sodium dodecyl sulfonate solution into a reaction kettle, heating to 80-90°C, and dripping sodium silicate solution and sulfuric acid solution while stirring, wherein the volume ratio of the sodium silicate solution to the sulfuric acid solution and the sodium dodecyl sulfonate solution is 2:3-5:1, and after the sodium silicate solution is dripped, the reaction temperature is controlled to be 80-95°C, and the sulfuric acid solution is continuously dripped until the pH value in the reaction system is 3.5-5.5, stirring is continuously performed, the reaction system is allowed to stand, and suction is filtered; 4) the filtered solid is rinsed with cooling water to obtain silicon dioxide slurry, and the obtained silicon dioxide slurry is spray-dried to obtain hydrated silicon dioxide.

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