Preparation method of sand blasting powder

Abstract

The invention belongs to the technical field of dental consumables, and particularly relates to a preparation method of sand blasting powder, which comprises the following steps: (1) heating a mixed solvent, adding an abrasive matrix until the abrasive matrix cannot be dissolved, then adding sodium citrate, and uniformly stirring to obtain an abrasive matrix saturated solution; (2) adding the composite micronucleus, then adding sodium chloride, and adopting a gradient cooling-seed crystal induction composite crystallization method to obtain a crystal; (3) after the crystallization is completed, carrying out suction filtration, rapidly washing the surfaces of the crystals by adopting precooled purified water or an ethanol-water mixed solution, and drying the washed wet crystals in a vacuum drying oven; and (4) post-treatment: crushing the dried crystals, adding a composite anti-caking agent, uniformly mixing, and sieving to obtain the sand blasting powder. According to the method, the pigment can be introduced into the sand blasting powder, different pigments are introduced corresponding to different types of sand blasting powder, different types of sand blasting powder are distinguished according to colors, rapid identification by naked eyes is facilitated, the cleaning effect is remarkable, color fading is not prone to occurring, and caking is not prone to occurring during storage.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of dental consumables, and particularly relates to a preparation method of sandblasting powder. BACKGROUND

[0002] A sandblasting technology uses compressed gas (usually air) to lift sandblasting powder and spray it onto the tooth surface, and a liquid medium (usually water) is sprayed at the same time to clean the tooth surface. Specifically, it can remove dental plaque, soft dirt, smoke stains, tea stains, etc., effectively prevent periodontal disease, and maintain dental health.

[0003] Sandblasting powder is the main consumable for sandblasting dental cleaning. Currently, major sandblasting powder manufacturers have developed a variety of sandblasting powders. Known types of sandblasting powder include sodium bicarbonate, glycine, erythritol, etc. For example, patent DE20009665U1 provides a dental sand powder, the main component of which is sodium bicarbonate or alumina or dolomite, and also contains components that have antibacterial, disinfecting, flavoring, etc. effects. In addition, patent DE10026718A1 also provides a sodium bicarbonate sand powder that can be used in a sandblasting device. In addition, patent EP2228175A1 provides a sand powder based on sugar alcohol, specifically erythritol. The sandblasting powders mentioned in the above patents and all sandblasting powders on the market are white powders. Doctors cannot quickly distinguish the model and particle size of the sand powder during clinical use. If a sand powder with color differentiation is put on the market, doctors can distinguish different models and particle sizes of the sand powder by color. The poured sand powder can also be quickly identified as which model, and it will not be confused when used again.

[0004] According to existing research, the factors affecting the use effect of sandblasting powder mainly include powder material hardness and powder particle size and taste. The hardness of the powder material determines whether the material can be used for dental cleaning. If the material is too soft, the cleaning effect is poor, and if it is too hard, it will damage the tooth surface. Therefore, it is very important to develop sandblasting powder with color and without affecting the dental cleaning effect of sandblasting powder. SUMMARY

[0005] The present application aims to solve the above technical problems and provides a preparation method of sandblasting powder. The method can introduce pigments into the sandblasting powder, introduce different pigments for different models of sandblasting powder, distinguish different models of sandblasting powder by color, facilitate quick identification by the naked eye, have significant cleaning effect, and not easily fade and not easily caking during storage.

[0006] The technical solution of the present application is a preparation method of sandblasting powder, comprising the following steps: (1) Preparation of abrasive matrix saturated solution: Heat the mixed solvent to 35°C, add abrasive matrix under stirring until the abrasive matrix cannot be dissolved, continue stirring for 15-20 minutes to obtain abrasive matrix saturated solution; (2) Add composite micronuclei and induce crystallization: Add composite micronuclei to the saturated solution of abrasive matrix in step (1) at 0.05%-1.2% of the mass of abrasive matrix, stir at 50-60 r / min for 25-35 min, then add sodium chloride at 3%-5% of the mass of abrasive matrix, and induce the formation of color and flavor integrated crystals by gradient cooling-seed induction composite crystallization method. (3) Filtration, washing and drying: After crystallization, the system is filtered to separate the crystals from the mother liquor. The surface of the crystals is quickly washed with pre-cooled purified water or ethanol-water mixture. The washed wet crystals are then dried in a vacuum oven. (4) Post-treatment: The dried crystals are crushed, and 0.1%-1.5% of the abrasive matrix mass of composite anti-caking agent is added and mixed evenly. After sieving, the sandblasting powder is obtained.

[0007] In order to ensure a significant cleaning effect without damaging the enamel due to excessive hardness, and also to allow for subsequent crystallization and encapsulation of color and odor components, preferably, in step (1) of the present invention, the abrasive matrix is ​​a mixture of sodium bicarbonate and calcium hydrogen phosphate in a mass ratio of 6-7:3-4. At this ratio, sodium bicarbonate has good solubility and is easy to rinse during cleaning, while calcium hydrogen phosphate has moderate hardness and can enhance the grinding effect. The two complement each other and work synergistically to significantly improve the cleaning power on teeth. At the same time, they can crystallize synergistically in a saturated solution to form a composite abrasive structure, providing a stable crystal framework for subsequent encapsulation of color and odor components.

[0008] To address the issues of poor solubility of traditional single solvents in abrasive matrices and the inability to balance abrasive stability with the dispersibility of subsequent pigments and sweeteners, which can lead to incomplete abrasive dissolution or the separation of functional components, preferably, in step (1) of this invention, the mixed solvent is made from the following raw materials in volume percentages: 28-32% ethanol, 0.05-0.08% xylitol, and purified water to 100%. Ethanol can improve the solubility of some water-insoluble components and reduce the surface tension of the solution, thus helping to disperse the abrasive uniformly. Xylitol has both solubility and compatibility, which can not only help dissolve some functional components but also form a synergistic effect with subsequent sweeteners. When combined with pure water to form a mixed solvent, it can achieve rapid dissolution of the abrasive matrix to form a saturated solution, while providing a stable solvent environment for the subsequent dispersion and crystallization process of composite micronuclei, and can also slightly improve the mild taste of the finished product.

[0009] When pigments and sweeteners are directly added to the system, uneven dispersion can lead to insufficient encapsulation during crystallization, and they are prone to volatilization and loss during subsequent processing or use, making it impossible to achieve long-term stable retention of color and flavor. To solve the above problems, preferably, in step (2) of the present invention, the preparation method of the composite micronucleus is as follows: the pigment and sweetener are mixed at a mass ratio of 1:1-4, stirred at 45-55℃ for 60-80 min, and dried to obtain the composite micronucleus. In the above method, nano-calcium carbonate, as a filler, can improve the structural stability of the micronucleus. Ball milling to a particle size of 1-3 μm allows the micronucleus to become the core site during crystallization. Silane coupling agent can enhance the interfacial bonding force between pigments, sweeteners and nano-calcium carbonate. Stirring at 45-55℃ can promote the full progress of the coupling reaction, so that the three form a tightly structured composite micronucleus. The prepared composite micronucleus can serve as a color and flavor carrier. During the crystallization process, it is uniformly coated by the abrasive matrix, which greatly reduces the loss of pigments and sweeteners. At the same time, the 1-3 μm particle size is suitable for subsequent crystal growth, ensuring the overall structure of the crystal is regular.

[0010] To achieve diverse flavor coloring of sandblasting powder, uniform coloring without irritation, and to ensure the stability of pigment properties during crystallization, drying and other processing stages, avoiding problems such as discoloration and off-odors, preferably, the pigment of the present invention is one of vegetable powder, iron oxide pigment, and water-soluble food coloring; the vegetable powder is one of pumpkin powder, red beet powder, cocoa powder, and purple sweet potato powder; the iron oxide pigment is one of iron oxide red, iron oxide yellow, and iron oxide black; and the water-soluble food coloring is one of lemon yellow, brilliant blue, and sunset red.

[0011] To improve compatibility with pigments and abrasive matrices, the sweetener of this invention is preferably a mixture of sodium saccharin and erythritol in a mass ratio of 3-4:1. In the sweetener of this invention, erythritol has a suitable sweetness and is not easily metabolized by oral bacteria, while sodium saccharin can enhance high-ratio sweetness. At the mass ratio of this invention, sweetness and mouthfeel are balanced. Both are biocompatible components that do not antagonize with abrasives or pigments and can synergistically integrate into the complex micronucleus.

[0012] To avoid problems such as uneven crystal size, loose structure, low composite micronucleus encapsulation rate, and crystal breakage, preferably, in step (2) of this invention, the gradient cooling-seed-induced composite crystallization method is as follows: (1) Cool down at a rate of 0.5℃ / min, increase the rotation speed to 150-200r / min, and control the initial pH of the solution to 8.0. When the temperature drops to 25℃, control the pH of the solution to 7.5 and add 0.01-0.03% composite abrasive seed crystals by mass of abrasive matrix; (2) When the temperature drops to 15℃, control the pH of the solution to 7.0 and keep it warm for 120-150 min.

[0013] The above method can induce the formation of uniform, dense crystals with integrated color and flavor, significantly improving the encapsulation rate of composite micronuclei while reducing crystal defects during crystallization and enhancing the mechanical stability of the crystals. Specifically: a gradient cooling rate of 0.5℃ / min avoids the formation of fine fragments due to excessively rapid cooling; phased pH control (8.0→7.5→7.0) adapts to the needs of different crystal growth stages; a rotation speed of 150-200 r / min promotes mixing of seed crystals and solution without damaging the crystal rudiments; and holding at this temperature for 120-150 min allows for sufficient crystal growth, improving structural density.

[0014] To simultaneously achieve crystal structure stability and oral-friendly properties, the composite abrasive seed crystals of this invention are preferably a mixture of sodium bicarbonate seed crystals and hydroxyapatite seed crystals in a mass ratio of 7-8:2-3. The sodium bicarbonate seed crystals have a particle size of 3-5 μm, and the hydroxyapatite seed crystals have a particle size of 1-3 μm. The sodium bicarbonate seed crystals, acting as the primary seed crystals, guide the abrasive matrix to form regular, near-spherical crystals, ensuring the cleaning power of the blasting powder. The hydroxyapatite seed crystals, acting as secondary seed crystals, embed within the crystal structure, releasing Ca²⁺ during subsequent use to aid in enamel repair, enhancing the product's added value in terms of care, and avoiding crystallization disorder caused by competition between seed crystals.

[0015] In order to improve the storage performance of sandblasting powder and avoid caking during storage, preferably, in step (4) of the present invention, the composite anti-caking agent is a mixture of fumed silica, calcium silicate and mannitol in a mass ratio of 1:1.5-3:0.2-0.5, which can significantly reduce the probability of sandblasting powder caking, maintain good fluidity after long-term storage, and at the same time not affect the grinding performance and oral safety of sandblasting powder, ensuring uniform spraying effect during use.

[0016] Due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows: 1. The method of the present invention can introduce pigments into sandblasting powder. Different pigments are introduced for different types of sandblasting powder to distinguish different types of sandblasting powder by color, which is easy to identify with the naked eye. The cleaning effect is significant, the color is not easy to fade, and the powder is not easy to clump during storage.

[0017] 2. The method of this invention controls product quality through a complete process of "preparing a saturated solution - inducing integrated color and flavor crystallization - purification and drying - post-treatment anti-caking". The composite micronucleus provides an attachment core for color and flavor components, and sodium chloride can regulate the osmotic pressure of the solution to promote crystallization. Gradient cooling and seed induction work together to ensure crystal formation. Pre-cooling and washing reduce crystal dissolution, and the composite anti-caking agent blocks particle agglomeration. Through this standardized sandblasting powder preparation process, it can induce the formation of structurally regular integrated color and flavor crystals, reduce the shedding of pigments and sweeteners in subsequent use, and reduce the probability of finished product agglomeration through post-treatment, thereby improving the batch stability of the product. Attached Figure Description

[0018] Figure 1 This is a picture of the sandblasting powder product prepared in Example 1 of the present invention. Detailed Implementation

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In the following embodiments: Sodium bicarbonate: food grade, purity ≥99.5%; Dicalcium phosphate: medical grade, particle size ≤10μm; Xylitol: food grade; Purified water: conductivity ≤10μS / cm; Vegetable powder, iron oxide pigment, water-soluble food coloring: food grade pigment, color value ≥100; Nano calcium carbonate: particle size 50nm, purity ≥99%; Silane coupling agent: KH-550; Sodium citrate: food grade; Sodium bicarbonate seed crystals: particle size 3-5μm; Hydroxyapatite seed crystals: particle size 1-3μm, medical grade.

[0021] The following performance testing methods are as follows: Particle size distribution: determined using a laser particle size analyzer; Stain removal rate: determined using a simulated cleaning experiment of artificial teeth; Pigment retention rate and sweetness retention rate: determined using an accelerated aging experiment (40℃, RH75%, 3 months); Anti-caking property: determined using GB / T 29858-2013; Enamel wear rate: determined using an atomic force microscope. Example

[0022] 1. Preparation of composite micronuclei (1) Weigh 25g of iron oxide red and 100g of sweetener (a mixture of sodium saccharin and erythritol in a mass ratio of 3.5:1) according to the proportion, add them to the agate grinding jar of the planetary ball mill, and add 0.3g of nano calcium carbonate at the same time, using anhydrous ethanol as the dispersion medium (solid-liquid ratio 1:1.5). (2) Set the ball mill parameters: rotation speed 2000 r / min, grinding time 45 min. After grinding, vacuum filtration was used to separate the powder to obtain a mixed powder with a particle size of 1-3 μm (detected by laser particle size analyzer, D50=2.1 μm). (3) Transfer the above mixed powder to a three-necked flask, add 50 mL of purified water and stir to disperse. After heating to 50 °C, add 0.2 g of silane coupling agent KH-550 and stir at a constant temperature of 150 r / min for 70 min. (4) After stirring, the material was transferred to a vacuum oven and dried at 45℃ and -0.09MPa for 3 hours to obtain 118.5g of white loose composite micronuclei.

[0023] 2. Preparation of sandblasting powder (1) Preparation of abrasive matrix saturated solution: Add the mixed solvent (300 mL ethanol + 0.5 g xylitol + 699.5 mL purified water) to a 5 L double-walled glass reactor, turn on the constant temperature water bath to heat to 35 °C, and start the stirring device (speed 180 r / min); add the abrasive matrix (650 g sodium bicarbonate + 350 g dicalcium phosphate) in batches, 100 g each time, with an interval of 5 min, until a small amount of undissolved abrasive matrix is ​​observed at the bottom of the reactor, continue stirring for 18 min to obtain a uniform and transparent abrasive matrix saturated solution (initial pH = 8.0 as measured by pH meter). (2) Adding composite micronuclei and inducing crystallization: Add 0.5g of composite micronuclei at 0.05% of the total mass of the abrasive matrix, adjust the stirring speed to 55r / min, and stir at a constant temperature for 30min to make the micronuclei uniformly dispersed; add 45g of sodium chloride, stir for 10min until completely dissolved, and then start the gradient cooling program; (3) Gradient cooling-seed-induced composite crystallization: The temperature was slowly reduced at a rate of 0.5℃ / min, while the stirring speed was increased to 180r / min; when the temperature dropped to 25℃, the pH was adjusted to 7.5 by adding 0.1mol / L sodium bicarbonate solution, and 0.2g of composite abrasive seed crystals were immediately added and the temperature was continued to drop; when the temperature dropped to 15℃, the pH was adjusted to 7.0 by adding 0.1mol / L hydrochloric acid solution, the cooling device was turned off, and the temperature was kept constant for 135min. A large number of granular crystals were observed to form in the reactor. (4) Filtration, washing and drying: After crystallization, the crystals and mother liquor were separated by vacuum filtration using a Buchner funnel (vacuum degree 0.08MPa); the crystals were washed three times with a mixture of ethanol and water (volume ratio 1:1) pre-cooled to 4℃ (50mL each time, washing time ≤10s) to remove residual mother liquor on the surface; the washed wet crystals were transferred to a vacuum drying oven, the temperature was set to 45℃ and the vacuum degree to -0.095MPa, and nitrogen gas was introduced for protection (flow rate 5L / min) to dry until the water content of the crystals was 0.65wt%, and 989.3g of dried crystals were obtained; (5) Post-processing: Add the dried crystals to the air jet mill, set the grinding pressure to 0.6 MPa and the grinding time to 3 min; after grinding, transfer to a three-dimensional mixer, add 1 g of composite anti-caking agent (a mixture of fumed silica, calcium silicate and mannitol with a mass ratio of 1:2.3:0.3), and mix at 150 r / min for 15 min; after mixing, sieve to remove a small amount of large particles and obtain 976.8 g of sandblasting powder.

[0024] Table 1 Performance indicators of the sandblasting powder prepared in Example 1 Example

[0025] 1. Preparation of composite micronuclei (1) Weigh 50g of pumpkin powder and 100g of sweetener (a mixture of sodium saccharin and erythritol in a mass ratio of 3:1) according to the proportion, add them to the agate grinding jar of the planetary ball mill, and add 0.5g of nano calcium carbonate at the same time, using anhydrous ethanol as the dispersion medium (solid-liquid ratio 1:1.5). (2) Set the ball mill parameters: rotation speed 2000 r / min, grinding time 45 min. After grinding, vacuum filtration was used to separate the powder to obtain a mixed powder with a particle size of 1-3 μm (detected by laser particle size analyzer, D50=2.3 μm). (3) Transfer the above mixed powder to a three-necked flask, add 50 mL of purified water and stir to disperse. After heating to 50 °C, add 0.1 g of silane coupling agent KH-550 and stir at a constant temperature of 150 r / min for 70 min. (4) After stirring, the material was transferred to a vacuum oven and dried at 45℃ and -0.09MPa for 3 hours to obtain 145.6g of white loose composite micronuclei.

[0026] 2. Preparation of sandblasting powder (1) Preparation of saturated abrasive matrix solution: Add the mixed solvent (320 mL ethanol + 0.6 g xylitol + 679.4 mL purified water) to a 5 L double-walled glass reactor, turn on the constant temperature water bath to heat to 35 °C, and start the stirring device (180 r / min); add the abrasive matrix (600 g sodium bicarbonate + 400 g dicalcium phosphate) in batches, 100 g each time, with an interval of 5 min, until a small amount of undissolved abrasive matrix is ​​observed at the bottom of the reactor, continue stirring for 18 min to obtain a uniform and transparent saturated abrasive matrix solution (initial pH = 8.0 as measured by pH meter). (2) Adding composite micronuclei and inducing crystallization: Add 5g of composite micronuclei at 0.5% of the total mass of the abrasive matrix, adjust the stirring speed to 55r / min, and stir at a constant temperature for 30min to make the micronuclei evenly dispersed; add 30g of sodium chloride, stir for 10min until completely dissolved, and then start the gradient cooling program; (3) Gradient cooling-seed-induced composite crystallization: The temperature was slowly reduced at a rate of 0.5℃ / min, while the stirring speed was increased to 180r / min; when the temperature dropped to 25℃, the pH was adjusted to 7.5 by adding 0.1mol / L sodium bicarbonate solution, and 0.3g of composite abrasive seed crystals were added immediately, and the temperature was continued to drop; when the temperature dropped to 15℃, the pH was adjusted to 7.0 by adding 0.1mol / L hydrochloric acid solution, the cooling device was turned off, and the temperature was kept constant for 135min. A large number of granular crystals were observed to form in the reactor. (4) Filtration, washing and drying: After crystallization, the crystals and mother liquor were separated by vacuum filtration using a Buchner funnel (vacuum degree 0.08MPa); the crystals were washed three times with a mixture of ethanol and water (volume ratio 1:1) pre-cooled to 4℃ (50mL each time, washing time ≤10s) to remove residual mother liquor on the surface; the washed wet crystals were transferred to a vacuum drying oven, the temperature was set to 45℃ and the vacuum degree to -0.095MPa, and nitrogen gas was introduced for protection (flow rate 5L / min) to dry until the water content of the crystals was 0.65wt%, and 989.3g of dried crystals were obtained; (5) Post-processing: Add the dried crystals to the air jet mill, set the grinding pressure to 0.6 MPa and the grinding time to 3 min; after grinding, transfer to a three-dimensional mixer, add 15 g of composite anti-caking agent (a mixture of fumed silica, calcium silicate and mannitol with a mass ratio of 1:3:0.2), and mix at 150 r / min for 15 min; after mixing, sieve to remove a small amount of large particles and obtain 976.8 g of sandblasting powder.

[0027] Table 2 Performance indicators of the sandblasting powder prepared in Example 2 Example

[0028] 1. Preparation of composite micronuclei (1) Weigh 35g of brilliant blue and 100g of sweetener (a mixture of sodium saccharin and erythritol in a mass ratio of 4:1) according to the proportion, add them to the agate grinding jar of the planetary ball mill, and add 0.2g of nano calcium carbonate at the same time, using anhydrous ethanol as the dispersion medium (solid-liquid ratio 1:1.5). (2) Set the ball mill parameters: rotation speed 2000 r / min, grinding time 45 min. After grinding, vacuum filtration was used to separate the particles to obtain mixed powder with a particle size of 1-3 μm (detected by laser particle size analyzer, D50=2.5 ​​μm). (3) Transfer the above mixed powder to a three-necked flask, add 50 mL of purified water and stir to disperse. After heating to 50 °C, add 0.3 g of silane coupling agent KH-550 and stir at a constant temperature of 150 r / min for 70 min. (4) After stirring, the material was transferred to a vacuum oven and dried at 45℃ and -0.09MPa for 3 hours to obtain 129.7g of white loose composite micronuclei.

[0029] 2. Preparation of sandblasting powder (1) Preparation of saturated abrasive matrix solution: Add the mixed solvent (280 mL ethanol + 0.8 g xylitol + 719.2 mL purified water) to a 5 L double-walled glass reactor, turn on the constant temperature water bath to heat to 35 °C, and start the stirring device (180 r / min); add the abrasive matrix (700 g sodium bicarbonate + 300 g dicalcium phosphate) in batches, 100 g each time, with an interval of 5 min, until a small amount of undissolved abrasive matrix is ​​observed at the bottom of the reactor, continue stirring for 18 min to obtain a uniform and transparent saturated abrasive matrix solution (initial pH = 8.0 as measured by a pH meter). (2) Adding composite micronuclei and inducing crystallization: Add 12g of composite micronuclei at 1.2% of the total mass of the abrasive matrix, adjust the stirring speed to 55r / min, and stir at a constant temperature for 30min to make the micronuclei uniformly dispersed; add 50g of sodium chloride, stir for 10min until completely dissolved, and then start the gradient cooling program; (3) Gradient cooling-seed-induced composite crystallization: The temperature was slowly reduced at a rate of 0.5℃ / min, while the stirring speed was increased to 180r / min; when the temperature dropped to 25℃, the pH was adjusted to 7.5 by adding 0.1mol / L sodium bicarbonate solution, and 0.1g of composite abrasive seed crystals was added immediately, and the temperature was continued to drop; when the temperature dropped to 15℃, the pH was adjusted to 7.0 by adding 0.1mol / L hydrochloric acid solution, the cooling device was turned off, and the temperature was kept constant for 135min. A large number of granular crystals were observed to form in the reactor. (4) Filtration, washing and drying: After crystallization, the crystals and mother liquor were separated by vacuum filtration using a Buchner funnel (vacuum degree 0.08MPa); the crystals were washed three times with a mixture of ethanol and water (volume ratio 1:1) pre-cooled to 4℃ (50mL each time, washing time ≤10s) to remove the residual mother liquor on the surface; the washed wet crystals were transferred to a vacuum drying oven, the temperature was set to 45℃ and the vacuum degree to -0.095MPa, and nitrogen gas was introduced for protection (flow rate 5L / min) to dry until the water content of the crystals was 0.65wt%, and 978.7g of dried crystals were obtained; (5) Post-processing: Add the dried crystals to the air jet mill, set the grinding pressure to 0.6 MPa and the grinding time to 3 min; after grinding, transfer to a three-dimensional mixer, add 8 g of composite anti-caking agent (a mixture of fumed silica, calcium silicate and mannitol with a mass ratio of 1:1.5:0.2), and mix at 150 r / min for 15 min; after mixing, sieve to remove a small amount of large particles and obtain 969.2 g of sandblasting powder.

[0030] Table 3 Performance indicators of the sandblasting powder prepared in Example 3

[0031] Depending on the requirements, the pigment can be replaced with one of the following: vegetable powder (such as beetroot powder, cocoa powder, purple sweet potato powder), iron oxide pigment (such as iron oxide yellow, iron oxide black), or water-soluble food coloring (such as lemon yellow, sunset red). The remaining preparation steps and parameters can be the same as in Example 1, and the corresponding sandblasting powder can be prepared.

[0032] Based on Example 1, only the amount of composite micronucleus added was changed, while all other conditions remained the same as in Example 1. Three groups of sandblasting powder samples were prepared, and the performance of the sandblasting powder was tested. The results are as follows:

[0033] Table 4. Effects of different composite microcore dosages on the performance of blasting powder

[0034] As shown in Table 4, when the amount of composite micronuclei is too small, the grinding effect of nano-calcium carbonate is insufficient, the friction efficiency of the abrasive surface decreases, and stubborn tobacco stains cannot be effectively removed, thus reducing the tobacco stain removal rate. When the amount of composite micronuclei is too small, the total amount of functional components is insufficient and unevenly distributed in the crystals, making them easy to be lost with the mother liquor during washing. There is almost no obvious color or taste when using it, so the pigment / sweetness retention rate is significantly reduced. When the amount of composite micronuclei is too small, the filling effect of the micronuclei particles is weakened, and the abrasive particles directly and rigidly contact the enamel, resulting in increased local wear and enamel wear. When the amount of composite micronuclei is too small, the anti-caking synergistic effect of nano-calcium carbonate is insufficient, and the powder particles are prone to agglomeration due to van der Waals forces, leading to early clumping during storage. When the amount of composite microcores used is excessive, the removal rate of tobacco stains increases, but the cost also increases relatively, reducing the cost-effectiveness. Excessive use of composite microcores, while resulting in a higher retention rate of pigments / sweetness, leads to an "overly strong color and flavor," causing oral discomfort for some users and failing to meet the gentleness requirements of oral care products. Excessive use of composite microcores reduces enamel wear, but the overall particle size distribution of the blasting powder narrows, resulting in excessive flowability and uneven material output from the blasting equipment, easily leading to localized accumulation or missed blasting. Excessive use of composite microcores also increases powder density, easily causing "bridging" during pouring, affecting ease of use, and causing clumping to occur relatively early. Therefore, to obtain the high-performance blasting powder of this invention, it is necessary to strictly control the amount of composite microcores added within the range specified in this invention.

[0035] Based on Example 1, only the composition of the anti-caking agent was changed, while all other conditions remained the same as in Example 1. Five groups of sandblasting powder samples were prepared, and the performance of the sandblasting powder was tested. The results are as follows: Table 5. Effects of different anti-caking agent compositions on the performance of sandblasting powder

[0036] As shown in Table 5, when fumed silica is lacking in the antagonist, the blasting powder is prone to caking during storage and transportation, leading to clogging of the blasting equipment or uneven powder output. This can also cause uneven cleaning efficiency and may create new adhesion points due to particle agglomeration, increasing the risk of pigment redeposition and resulting in a significant decrease in pigment retention rate. When mannitol is lacking in the antagonist, the flowability and dispersibility of the powder deteriorate, and it is also prone to caking after storage. When calcium silicate is lacking in the antagonist, it loses its moisture-absorbing auxiliary function, and its anti-caking ability weakens, especially in humid environments, making it prone to caking during storage. When fumed silica is replaced with nano-sized magnesium stearate in the antagonist, magnesium stearate is hydrophobic. For abrasives mainly composed of water-soluble salts (sodium bicarbonate), it can provide good lubrication and anti-caking in dry environments. However, once it comes into contact with oral moisture or water, the hydrophobic layer may be damaged, leading to local agglomeration. Its anti-caking effect is more sensitive to humidity and also disrupts the balance of the entire anti-caking agent system. Its overall stability and reliability are not as good as fumed silica. In summary, the anti-caking agent of the present invention has a synergistic effect that can provide the anti-caking properties of the sandblasting powder of the present invention, improve the storage performance of the sandblasting powder of the present invention, and ensure the cleaning effect and pigment retention of the sandblasting powder.

[0037] The above description is a detailed description of the preferred embodiments of the present invention. However, the embodiments are not intended to limit the scope of the patent application of the present invention. All equivalent changes or modifications made under the technical spirit of the present invention should fall within the patent scope covered by the present invention.

Claims

1. A method for preparing sandblasting powder, characterized in that, Includes the following steps: (1) Preparation of abrasive matrix saturated solution: Heat the mixed solvent to 35°C, add abrasive matrix under stirring until the abrasive matrix cannot be dissolved, continue stirring for 15-20 minutes to obtain abrasive matrix saturated solution; (2) Add composite micronuclei and induce crystallization: Add composite micronuclei to the saturated solution of abrasive matrix in step (1) at 0.05%-1.2% of the mass of abrasive matrix, stir at 50-60 r / min for 25-35 min, then add sodium chloride at 3%-5% of the mass of abrasive matrix, and induce the formation of color and flavor integrated crystals by gradient cooling-seed induction composite crystallization method. (3) Filtration, washing and drying: After crystallization, the system is filtered to separate the crystals from the mother liquor. The surface of the crystals is quickly washed with pre-cooled purified water or ethanol-water mixture. The washed wet crystals are then dried in a vacuum oven. (4) Post-treatment: The dried crystals are crushed, and 0.1%-1.5% of the abrasive matrix mass of composite anti-caking agent is added and mixed evenly. After sieving, the sandblasting powder is obtained.

2. The method for preparing the sandblasting powder as described in claim 1, characterized in that: In step (1), the abrasive matrix is ​​a mixture of sodium bicarbonate and calcium hydrogen phosphate in a mass ratio of 6-7:3-4, or a pure matrix of sodium bicarbonate, erythritol, and glycine.

3. The method for preparing the sandblasting powder as described in claim 1, characterized in that: In step (1), the mixed solvent is made from the following raw materials in volume percentages: 28-32% ethanol, 0.05-0.08% xylitol, and purified water added to 100%.

4. The method for preparing the sandblasting powder as described in claim 1, characterized in that: In step (2), the preparation method of the composite micronucleus is as follows: the pigment and sweetener are mixed at a mass ratio of 1:1-4, stirred at 45-55℃ for 60-80 minutes, and dried to obtain the composite micronucleus.

5. The method for preparing the sandblasting powder as described in claim 4, characterized in that: The pigment is one of vegetable powder, iron oxide pigment, or water-soluble food coloring.

6. The method for preparing the sandblasting powder as described in claim 5, characterized in that: The vegetable powder is one of pumpkin powder, red beet powder, cocoa powder, and purple sweet potato powder; the iron oxide pigment is one of iron oxide red, iron oxide yellow, and iron oxide black; and the water-soluble food coloring is one of lemon yellow, brilliant blue, and sunset red.

7. The method for preparing the sandblasting powder as described in claim 4, characterized in that: The sweetener is a mixture of sodium saccharin and erythritol in a mass ratio of 3-4:

1.

8. The method for preparing the sandblasting powder as described in claim 1, characterized in that: In step (2), the specific method of gradient cooling-seed-induced composite crystallization is as follows: (1) Cool down at a rate of 0.5℃ / min, increase the rotation speed to 150-200r / min, and control the initial pH of the solution to 8.

0. When the temperature drops to 25℃, control the pH of the solution to 7.5 and add 0.01-0.03% composite abrasive seed crystals by mass of abrasive matrix; (2) When the temperature drops to 15℃, control the pH of the solution to 7.0 and keep it warm for 120-150 min.

9. The method for preparing the sandblasting powder as described in claim 8, characterized in that: The composite abrasive seed crystals are a mixture of sodium bicarbonate / erythritol / glycine seed crystals and hydroxyapatite seed crystals in a mass ratio of 7-8:2-3. The particle size of the sodium bicarbonate / erythritol / glycine seed crystals is 3-5 μm, and the particle size of the hydroxyapatite seed crystals is 1-3 μm.

10. The method for preparing the sandblasting powder as described in claim 1, characterized in that: In step (4), the composite anti-caking agent is a mixture of fumed silica, calcium silicate and mannitol in a mass ratio of 1:1.5-3:0.2-0.5.

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