Damp-proof bath salt ball and preparation method thereof

Abstract

The invention relates to the field of bath salt balls, and discloses a damp-proof bath salt ball and a preparation method thereof. The moisture-proof bath salt ball is prepared from the following raw materials in parts by weight: 40-60 parts of sodium bicarbonate; 10 to 20 parts of anhydrous sodium sulphate; 28 to 35 parts of citric acid; 30-40 parts of a moisture-proof agent; 1-3 parts of a surfactant; 1-3 parts of a humectant; 0.2 to 0.5 part of essence; 0.05 to 0.25 part of toner; the moisture-proof agent is prepared from soluble starch, bentonite, titanium dioxide and a composite tackifier; the composite tackifier is prepared from dodecyl dimethyl amine oxide, chitosan quaternary ammonium salt and polyquaternium-7. The preparation process comprises the following steps: step-by-step dispersion and sieving, and finally kneading, dispersing and profiling. The prepared bath salt ball is not easy to deliquesce in a long-term storage process, easy to dissolve in use and good in foam stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of bath salt balls, in particular to a moisture-proof bath salt ball and a preparation method thereof. BACKGROUND

[0002] The bath salt ball is a bath care product, and the main components include an acid source such as citric acid, an alkali source such as sodium bicarbonate, and various functional additives such as fragrances and essential oils. When used, the acid source and the alkali source rapidly undergo acid-base neutralization reaction and generate carbon dioxide gas to form a foaming effect, thereby relaxing the body and mind and cleaning the skin.

[0003] In the production of the bath salt ball, a binding and isolation system mainly composed of soluble starch is generally used, which has the advantages of low raw material cost, easy availability, and compliance with natural environmental protection. The addition of soluble starch has the following functions: on the one hand, soluble starch acts as a binder to bind various powdered raw materials into a wet blank under the action of wetting agents such as glycerol and polyethylene glycol, so that the wet blank has sufficient plasticity for compression molding; on the other hand, soluble starch acts as a physical isolation agent, and fine particles can coat and separate the acid component and the alkali component to some extent, thereby reducing the direct contact area between the two and delaying the premature reaction caused by moisture absorption during storage.

[0004] However, the above technical solution of using starch as a binder and an isolation agent has obvious defects in terms of actual long-term storage stability and product reliability: in order to achieve effective binding, a large amount of wetting agent must be added to the system to keep the soluble starch sticky, and the added wetting agent is difficult to completely dry even after subsequent drying, which continuously promotes the moisture absorption and deliquescence of the acid component and the alkali component during storage, thereby reducing the moisture-proof efficiency of the bath salt ball during long-term storage; and after long-term storage, the surface of the bath salt ball is prone to partial hardening, which makes it difficult for the bath salt ball to dissolve quickly after being put into water during use, thereby reducing the use experience of the bath salt ball. SUMMARY

[0005] In order to solve the problems of deliquescence of the existing bath salt ball during long-term storage and low solubility during use, the present application provides a moisture-proof bath salt ball and a preparation method thereof.

[0006] In a first aspect, the present application provides a moisture-proof bath salt ball, which adopts the following technical solution: A moisture-proof bath salt ball is prepared from the following raw materials by weight: 40-60 parts of sodium bicarbonate; 10-20 parts of anhydrous sodium sulfate; 28-35 parts of citric acid; Damp-proof agent 30-40 parts; Surfactant 1-3 parts; Moisturizer 1-3 parts; Essence 0.2-0.5 parts; Color powder 0.05-0.25 parts; The damp-proof agent is composed of soluble starch, bentonite, titanium dioxide and a composite tackifier; The composite tackifier is composed of dodecyl dimethyl amine oxide, chitosan quaternary ammonium salt and polyquaternium-7.

[0007] By adopting the technical scheme, the bath salt ball of the application takes sodium bicarbonate as an alkali source and citric acid as an acid source. When the bath salt ball is used, the sodium bicarbonate and the citric acid can produce carbon dioxide gas through acid-base neutralization reaction in water. The anhydrous sodium sulfate as a filler and a foam stabilizer can cooperate with the surfactant to produce uniform and stable foam under the action of carbon dioxide gas bubbles, so as to endow the bath salt ball with excellent cleaning effect and comfortable bathing performance. The moisturizer can prevent dryness and keep the skin moist. The essence can endow the bath salt ball with pleasant aroma and relax the body and mind. The color powder can provide the bath salt ball with beautiful color.

[0008] The damp-proof agent serves as a binder and a barrier for the sodium bicarbonate and the citric acid. The soluble starch serves as a binding and damp-proof matrix, so as to endow the bath salt ball with basic binding and damp-proof performance. The bentonite has good adsorption and swelling properties, and is dispersed with the soluble starch to reduce the invasion of external moisture. The titanium dioxide can further enhance the physical barrier performance of the damp-proof agent. The dodecyl dimethyl amine oxide, the chitosan quaternary ammonium salt and the polyquaternium-7 in the composite tackifier can further cooperate with the soluble starch, the bentonite and the titanium dioxide to increase the adhesive stability between the components, so as to make the damp-proof agent more tightly and stably wrap and bond the sodium bicarbonate and the citric acid.

[0009] The bath salt ball prepared by the application is not prone to deliquescence during long-term storage, has good foam stability and can effectively prolong the shelf life. When used, the composite tackifier can quickly form a stable dispersion system in water under the dispersion effect of the composite tackifier in water, so as to make the bath salt ball quickly dissolve, improve the dissolution efficiency of the bath salt ball and further improve the use experience of the bath salt ball.

[0010] Preferably, the composite tackifier is composed of dodecyl dimethyl amine oxide, chitosan quaternary ammonium salt and polyquaternium-7 in a weight ratio of 1: (2-4): (0.4-0.6).

[0011] By adopting the technical scheme, the chitosan quaternary ammonium salt is used as the main component in the composite tackifier, a uniform adhesive film can be formed, the polyquaternium-7 can further cooperate with the chitosan quaternary ammonium salt to produce good film stability, the long-chain alkyl of the dodecyl dimethyl amine oxide can further endow the adhesive film with excellent softness and hydrophobicity, the three components cooperate in an optimal proportion, the moisture-proof agent can further improve the wrapping and isolation performance of sodium bicarbonate and citric acid, thereby improving the long-term storage stability of the bath salt ball, and when used, the composite tackifier with the optimal components can quickly form a uniform dispersion system in water, so that the bath salt ball can be quickly dissolved.

[0012] Preferably, the moisture-proof agent is prepared from the following raw materials by weight: Soluble starch 80-100 parts; Bentonite 5-10 parts; Titanium dioxide 14-20 parts; Composite tackifier 1.2-1.8 parts.

[0013] By adopting the technical scheme, the moisture-proof agent uses soluble starch as the main moisture-proof component, bentonite and titanium dioxide are compounded as auxiliary moisture-proof components, and an optimal amount of composite tackifier is used to optimize the moisture-proof performance while ensuring that the bath salt ball has good rapid dissolution performance. In actual testing, it is found that if the composite tackifier is too much, the initial foam is rich and dissolves quickly, but after a period of time, the moisture-proof performance and rapid dissolution performance of the bath salt ball are reduced.

[0014] Preferably, the soluble starch is corn pregelatinized starch and / or cassava pregelatinized starch.

[0015] By adopting the technical scheme, the corn pregelatinized starch and the cassava pregelatinized starch are both prepared by gelatinization treatment, and compared with conventional starch, they have the characteristics of cold water solubility and good viscosity, and can play a good moisture-proof, bonding and filling role in the bath salt ball.

[0016] Preferably, the moisture-proof agent is prepared by the following steps: A1, uniformly mixing bentonite and titanium dioxide to form a mixture, then adding a composite tackifier to the mixture, dispersing, and preparing a pretreated mixture; A2, dispersing the pretreated mixture and soluble starch to prepare a moisture-proof agent.

[0017] By adopting the technical scheme, in step A1, the bentonite and titanium dioxide are first sprayed and treated with the composite tackifier, the bentonite and titanium dioxide are coated with the composite tackifier, and the bonding force of the bentonite and titanium dioxide with the organic starch matrix is improved. Step A2 is performed to disperse the whole, which can ensure uniform dispersion of each component and form a stable and uniform moisture-proof agent, which is beneficial to improving the overall density of the bath salt ball prepared subsequently, and further improving the moisture-proof performance.

[0018] Preferably, the dispersion temperature in the A2 step is 40-50℃, and the dispersion time is 20-40min.

[0019] By adopting the technical scheme, the optimal dispersion condition can give the moisture-proof agent excellent bulk density and dispersion performance, and improve the uniformity and stability of the coating of sodium bicarbonate and citric acid.

[0020] Preferably, the surfactant is any one or combination of sodium lauroamphoacetate, cocamidopropyl betaine, and lauryl glucoside.

[0021] By adopting the technical scheme, these nonionic surfactants not only can provide the required cleaning and foaming functions of the bath salt ball, but also have good compatibility with the acid-base system of the bath salt ball and the components of the moisture-proof agent, can synergistically improve the foam stability, and will not introduce adverse side reactions or affect the storage stability.

[0022] Preferably, the humectant is any one or combination of polyethylene glycol, vitamin E, sodium hyaluronate, trehalose, and squalane.

[0023] By adopting the technical scheme, the humectant can give the bath salt ball excellent moisturizing effect. And while achieving the moisturizing effect, it can reduce the risk of moisture absorption of the bath salt ball due to the addition of the humectant.

[0024] In a second aspect, the application provides a preparation method of a moisture-proof bath salt ball, which adopts the following technical scheme: A preparation method of a moisture-proof bath salt ball, comprising the following steps: Mixing, drying, sieving, and preparing material A of sodium sulfate, surfactant, humectant, fragrance, and color powder; Mixing sodium bicarbonate and moisture-proof agent to prepare material B; Pulverizing and sieving citric acid to prepare material C; Mixing material A and material B uniformly, then adding material C and mixing uniformly to prepare a semi-finished product; Molding the semi-finished product to prepare a moisture-proof bath salt ball.

[0025] By adopting the above technical scheme, the material A takes anhydrous sodium sulfate as the main component, takes the anhydrous sodium sulfate as the carrier of the surfactant, the moisturizer, the essence and the color powder, is mixed and then is dried and sieved, the particle uniformity of the material A is improved, and the moisture is strictly controlled; the sodium bicarbonate is dispersed into the moisture-proof agent in the material B, the moisture-proof agent is coated on the sodium bicarbonate, a uniform coating system is formed; the material C is the citric acid with uniform particle size after being crushed and sieved, the citric acid is very easy to absorb water, and therefore is taken as the material C alone; the material A and the material B are dispersed first, and then the material C is added and dispersed, so that the citric acid is fully dispersed into the system.

[0026] The step-by-step mixing process of grouping the raw materials into the material A, the material B and the material C and then pressing the materials finally makes the bath salt ball have excellent structural stability, which is helpful to improve the moisture resistance of the bath salt ball.

[0027] Preferably, the mesh number of the sieve for sieving is 40-50 meshes.

[0028] By adopting the above technical scheme, the sieving with 40-50 meshes can ensure that the raw material powder has appropriate and uniform fineness. The uniform fineness is beneficial to the uniform mixing of the components and avoids caking; can ensure that the bath salt ball has good fluidity and formability when being pressed, and the bath salt ball prepared has uniform texture and smooth surface, and is also beneficial to the rapid disintegration of the bath salt ball in water.

[0029] In summary, the present application has at least one of the following beneficial technical effects: 1. The moisture-proof bath salt ball is prepared from sodium bicarbonate, anhydrous sodium sulfate, citric acid, a moisture-proof agent, a surfactant, a moisturizer, an essence and a color powder, the moisture-proof agent is composed of soluble starch, bentonite, titanium dioxide and a composite tackifier, the composite tackifier is composed of dodecyl dimethyl amine oxide, chitosan quaternary ammonium salt and polyquaternium-7, the bath salt ball prepared is not easy to deliquesce during long-term storage, has good foam stability and can effectively prolong the shelf life; and the bath salt ball dissolves quickly when being used, improving the use experience of the bath salt ball.

[0030] 2. The preparation process of the present application mixes, dries and sieves the anhydrous sodium sulfate, the surfactant, the moisturizer, the essence and the color powder to prepare the material A, mixes the sodium bicarbonate and the moisture-proof agent to prepare the material B, crushes and sieves the citric acid to prepare the material C, then mixes the material A and the material B, and finally adds the material C to mix uniformly to prepare a semi-finished product, and finally the semi-finished product is pressed, the step-by-step mixing process makes the bath salt ball prepared have good structural stability and uniformity, and further improves the moisture resistance and dissolution performance of the bath salt ball. DETAILED DESCRIPTION

[0031] The present application is further described in detail below in combination with the preparation examples and the examples.

[0032] The following is the source and specification of part of the raw materials of the present application, the raw materials used in the preparation examples and examples of the present application can be obtained by market, including but not limited to the following type and manufacturer of raw materials, the same performance of raw materials can be used: 1. Soluble starch: Corn pregelatinized starch: brand Mingjiang, content 99%, mesh 60-90, density 1.1 g / ml; Tapioca pregelatinized starch: brand Youke Chemical Industry, content 98%, mesh 60-100, density 1.21 g / ml; 2. Bentonite: Haimings organic bentonite Bentone 27; 3. Titanium dioxide: particle size 1-3 µm; 4. Chitosan quaternary ammonium salt: hydroxypropyl trimethyl ammonium chloride chitosan HACC, content 99%; 5. Polyquaternium-7: model M550.

[0033] Preparation example of moisture-proof agent Preparation example 1 Preparation example 1 discloses a moisture-proof agent, which is prepared by the following steps: A1, 0.5 kg of bentonite and 2 kg of titanium dioxide with a particle size of 1 µm are mixed uniformly to form a mixture, then 0.12 kg of composite tackifier is added to the mixture, and the mixture is dispersed at a temperature of 80 ℃ and a stirring speed of 40 r / min for 40 min to prepare a pretreated mixture; A2, the pretreated mixture and 8 kg of soluble starch are dispersed, the dispersion temperature is controlled at 40 ℃, and the dispersion time is 40 min to prepare a moisture-proof agent; The composite tackifier is composed of dodecyl dimethyl amine oxide, chitosan quaternary ammonium salt and polyquaternium-7 with a weight ratio of 1:1:1; the soluble starch is composed of corn pregelatinized starch and tapioca pregelatinized starch with a weight ratio of 2:1.

[0034] Preparation examples 2-3 Preparation examples 2-3 are different from preparation example 1 in that the amount of raw materials and preparation parameters are different, for details, see Table 1 below.

[0035] Table 1 Parameters of preparation examples 1-3

[0036] Preparation example 4 Preparation example 4 is different from preparation example 3 in that the amount of composite tackifier is 0.28 kg, and the others are the same as preparation example 3.

[0037] Preparation comparative example 1 The difference between the preparation of comparative example 1 and preparation example 3 is that the polyquaternary ammonium salt-7 in the composite tackifier is replaced by chitosan quaternary ammonium salt in equal amount, and the rest is the same as preparation example 3.

[0038] Preparation of comparative example 2 The difference between the preparation of comparative example 2 and preparation example 3 is that the dodecyl dimethyl amine oxide in the composite tackifier is replaced by chitosan quaternary ammonium salt in equal amount, and the rest is the same as preparation example 3.

[0039] Preparation of comparative example 3 The difference between the preparation of comparative example 3 and preparation example 3 is that the chitosan quaternary ammonium salt is replaced by polyethylene glycol 400 in equal amount, and the rest is the same as preparation example 3.

[0040] Preparation of comparative example 4 The difference between the preparation of comparative example 4 and preparation example 3 is that no composite tackifier is added, and the rest is the same as preparation example 3.

[0041] Preparation of comparative example 5 The difference between the preparation of comparative example 5 and preparation example 3 is that bentonite is replaced by sodium alginate in equal amount, and the rest is the same as preparation example 3.

[0042] Preparation of comparative example 6 The difference between the preparation of comparative example 6 and preparation example 3 is that the composite tackifier is replaced by sodium carboxymethyl cellulose in equal amount, and the rest is the same as preparation example 3. Example Example 1

[0043] Example 1 discloses a moisture-proof bath salt ball, which is prepared by the following steps: Mix 1 kg of alum, 0.1 kg of surfactant, 0.1 kg of humectant, 0.02 kg of essence and 0.005 kg of color powder, dry at a temperature of 80℃ for 40 min, sieve, the mesh number is 40 meshes, if there are some agglomerated particles, crush and continue to sieve, to prepare material A; Mix 4 kg of sodium bicarbonate and 3 kg of moisture-proof agent prepared in preparation example 1 to prepare material B; Crush and sieve 2.8 kg of citric acid, the mesh number is 40 meshes, if there are some agglomerated particles, crush and continue to sieve, to prepare material C; Mix material A and material B uniformly, then add material C and mix uniformly to prepare a semi-finished product; Use a molding equipment with a mold to press the semi-finished product to prepare a moisture-proof bath salt ball; The surfactant is composed of sodium lauroylamphoteric acid and lauryl glucoside in a weight ratio of 1:1; the moisturizer is composed of polyethylene glycol 400, vitamin E and sodium hyaluronate in a weight ratio of 5:0.2:1; the colorant is a compound of red 28 (C1 45410) and blue 1 (C1 42090).

[0044] Example 2-3 The difference between Examples 2-3 and Example 1 lies in the amount of raw materials used and the preparation conditions, as detailed in Table 2 below.

[0045] Table 2 Parameter Table for Examples 1-3

[0046] Example 4

[0047] The difference between Example 4 and Example 3 is that the desiccant is derived from Preparation Example 4, while the rest is the same as Example 3.

[0048] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 3 is that the desiccant was derived from the preparation of Comparative Example 1, while the rest is the same as Example 3.

[0049] Comparative Example 2 The difference between Comparative Example 2 and Example 3 is that the desiccant was derived from the preparation of Comparative Example 2, while the rest is the same as Example 3.

[0050] Comparative Example 3 The difference between Comparative Example 3 and Example 3 is that the desiccant was derived from the preparation of Comparative Example 3, while the rest is the same as Example 3.

[0051] Comparative Example 4 The difference between Comparative Example 4 and Example 3 is that the desiccant was derived from the preparation of Comparative Example 4, while the rest is the same as Example 3.

[0052] Comparative Example 5 The difference between Comparative Example 5 and Example 3 is that the desiccant was derived from the preparation of Comparative Example 5, while the rest is the same as Example 3.

[0053] Comparative Example 6 The difference between Comparative Example 6 and Example 3 is that the desiccant was derived from the preparation of Comparative Example 6, while the rest is the same as Example 3.

[0054] Comparative Example 7 The difference between Comparative Example 7 and Example 3 is that the desiccant is soluble starch, while the other parameters are the same as in Example 3.

[0055] Performance testing The following are the performance test data of the moisture-proof bath salt balls prepared in Examples 1-4 and Comparative Examples 1-7. See Table 3 below for details. Bath salt ball specifications: 55g per ball; Moisture-proof performance and dissolution time test: Take 6 bath salt balls, 3 balls for each group, corresponding to the maximum foam height (unit: ml) and dissolution time of the test bath salt balls at 0 days and after being sealed and placed in an environment with a temperature of 35°C and a humidity of 70% for 45 days, respectively. Take the average value of each group of bath salt balls and record it; The foam height test method is as follows: Take a 1L graduated cylinder with the smallest scale of 10ml, pour 500ml of water with a temperature of 25°C, put the bath salt ball into it, measure the maximum foaming height (unit: ml), test and record the test results, dissolution time ≤5min is qualified, foam height ≥150ml is qualified; The following are the performance test data of the moisture-proof bath salt balls prepared in Examples 1-4 and Comparative Examples 1-7. See Table 3 below for details.

[0056] Table 3 Performance data of moisture-proof bath salt balls prepared in Examples 1-4 and Comparative Examples 1-7

[0057] Based on the above experimental data, the following conclusions can be drawn: Compared with Example 3, Example 4 increased the proportion of the composite tackifier, and the initial maximum foam height of the prepared bath salt ball increased by 10ml, and the dissolution time decreased by 5s, but after 45 days of testing, the maximum foam height decreased to 220ml, and the dissolution time increased to 4 minutes and 4 seconds. It may be because the use of a large amount of composite tackifier improves the dispersion performance of the bath salt ball system at the beginning, optimizes the foam and dissolution time of the bath salt ball, but after a long time of storage, the large amount of tackifier causes a slight reaction between sodium bicarbonate and citric acid, causing the bath salt ball to become hard, thereby reducing the foam stability and dissolution efficiency of the bath salt ball after a long time of storage, and thus reducing the moisture-proof performance of the bath salt ball.

[0058] Compared with Example 3, Comparative Examples 1-3 changed the component types of the composite tackifier, and the initial maximum foam height of the prepared bath salt ball decreased, and the dissolution time increased, and after 45 days of testing, the maximum foam height decreased to different degrees, and the dissolution time increased from about three minutes to more than four minutes. It may be because the component types of the composite tackifier are changed, which reduces the foam synergistic effect of the moisture-proof agent, surfactant, sodium bicarbonate and sodium carbonate in the bath salt ball.

[0059] Comparative Example 4 does not add tackifier compared with Example 3; and Comparative Example 6 replaces the composite tackifier with sodium carboxymethyl cellulose compared with Example 3, and the initial maximum foam height of the bath salt ball prepared is reduced, and the dissolution time is obviously increased; after 45 days of testing, the maximum foam height is obviously reduced, and the dissolution time is obviously increased. It may be because the foaming performance of the bath salt ball is reduced without the synergistic effect of the better composite tackifier, and after long-term wet heat testing, the bath salt ball is self-reacted and hardened, thereby the dissolution time is obviously increased.

[0060] Comparative Example 5 replaces bentonite in the moisture-proof agent with sodium alginate compared with Example 3, although the initial maximum foam height of the bath salt ball does not change much, but the dissolution time is increased; and after 45 days of testing, the maximum foam height is reduced, and the dissolution time is increased. It may be because the synergistic effect of sodium alginate in the moisture-proof agent is low, and it is easy to produce ion adsorption with the composite tackifier in the system, thereby the maximum foam height of the bath salt ball prepared is reduced after wet heat testing, and the dissolution time is increased.

[0061] Comparative Example 7 uses only soluble starch as a moisture-proof agent compared with Example 3, and the maximum foam height of the bath salt ball prepared after 45 days of testing is 130 ml, and the dissolution time is 6 minutes and 21 seconds, which shows that using only soluble starch as a moisture-proof agent, after a long time of storage, the bath salt ball is easy to absorb water vapor in the humid air and react and harden itself, thereby the maximum foam height is obviously reduced, and the dissolution time is obviously increased.

[0062] In summary, the bath salt ball prepared in the application has good moisture resistance, long-term storage foam stability and dissolution stability.

[0063] The specific embodiments are only an explanation of the application, and are not a limitation of the application, and those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, as long as the modifications are within the scope of the claims of the application, and are protected by the patent law.

Claims

1. A moisture-proof bath salt ball, characterized in that, It is prepared from the following raw materials in parts by weight: 40-60 parts sodium bicarbonate; 10-20 parts of sodium sulfate; Citric acid 28-35 parts; 30-40 parts of desiccant; 1-3 parts surfactant; 1-3 parts moisturizer; Fragrance 0.2-0.5 parts; Pigment powder 0.05-0.25 parts; The moisture-proofing agent is composed of soluble starch, bentonite, titanium dioxide and a composite thickener; The composite thickener is composed of dodecyl dimethylamine oxide, chitosan quaternary ammonium salt, and polyquaternary ammonium salt-7.

2. The moisture-proof bath salt ball according to claim 1, characterized in that, The composite tackifier is composed of dodecyl dimethylamine oxide, chitosan quaternary ammonium salt and polyquaternary ammonium salt-7 in a weight ratio of 1:(2-4):(0.4-0.6).

3. The moisture-proof bath salt ball according to claim 1, characterized in that, The desiccant is prepared from the following raw materials in parts by weight: 80-100 parts soluble starch; 5-10 parts bentonite; 14-20 parts of titanium dioxide; 1.2-1.8 parts of composite tackifier.

4. A moisture-proof bath salt ball according to claim 1, characterized in that, The soluble starch is corn pregelatinized starch and / or cassava pregelatinized starch.

5. A moisture-proof bath salt ball according to any one of claims 1-4, characterized in that, The desiccant is prepared by the following steps: A1. Mix bentonite and titanium dioxide evenly to form a mixture, then add the composite thickener to the mixture for dispersion to obtain a pretreated mixture; A2. Disperse the pretreated mixture and soluble starch to obtain a desiccant.

6. A moisture-proof bath salt ball according to claim 5, characterized in that, The dispersion temperature in step A2 is 40-50℃, and the dispersion time is 20-40 min.

7. A moisture-proof bath salt ball according to claim 1, characterized in that, The surfactant is any one or a combination of sodium lauroylamphoteric acid, cocamidopropyl betaine, and lauryl glucoside.

8. A moisture-proof bath salt ball according to claim 1, characterized in that, The moisturizer is any one or a combination of polyethylene glycol, vitamin E, sodium hyaluronate, trehalose, and squalane.

9. A preparation process for a moisture-proof bath salt ball as described in any one of claims 1-8, characterized in that, Includes the following steps: The sodium sulfate, surfactant, humectant, fragrance and colorant are mixed, dried and sieved to obtain material A; Sodium bicarbonate and a desiccant are mixed to obtain material B; Citric acid was pulverized and sieved to obtain material C; Mix material A and material B evenly, then add material C and mix evenly to obtain a semi-finished product; The semi-finished product is pressed into shape to obtain moisture-proof bath salt balls.

10. The preparation process of a moisture-proof bath salt ball according to claim 9, characterized in that, The sieve mesh size is 40-50 mesh.

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