A high-hygroscopic, water-free composite gel-type calcium and magnesium salt tablet and its preparation method

Abstract

This invention provides a high-hygroscopic, water-free composite gel-type calcium and magnesium salt tablet and its preparation method, which is made from the following raw materials in parts by weight: 45-70 parts calcium and magnesium salt, 15-25 parts gum arabic, 3-15 parts mica powder, 2-12 parts polyethylene oxide, 0.5-2 parts sodium nitrite, and 2-30 parts gelatin. This tablet exhibits high hygroscopicity and excellent physical properties.

Description

Technical Field

[0001] This invention relates to a composite gel-type calcium magnesium salt tablet with high moisture absorption and no liquid water, and its preparation method, belonging to the field of desiccant preparation technology. Background Technology

[0002] Currently, most tablet desiccants on the market suitable for precision equipment, the electronics industry, and small-space applications are fiber desiccants, silica gel desiccants, and diatomaceous earth desiccants. However, these desiccants generally suffer from low moisture absorption rates, with most failing to meet the 100%-200% moisture absorption rate requirement. Although calcium and magnesium salt compounds (such as magnesium chloride and calcium chloride) have excellent moisture absorption properties, there are two main technical challenges in formulating them into tablet desiccants: after being compressed into tablets, calcium and magnesium salts readily form liquid water upon absorbing moisture, leading to secondary pollution; and existing calcium and magnesium salt tablets are difficult to improve in terms of moisture absorption rate and lack sufficient mechanical strength. Therefore, calcium and magnesium salt desiccants on the market are mostly available in powder form, lacking high-performance tablet products and mature preparation methods. Summary of the Invention

[0003] This invention provides a composite gel-type calcium and magnesium salt tablet with high hygroscopicity and no liquid water, and a preparation method thereof, which can effectively solve the above problems.

[0004] This invention provides a high-hygroscopic, water-free composite gel-type calcium and magnesium salt tablet, made from the following raw materials in parts by weight: 45-70 parts calcium and magnesium salt, 15-25 parts gum arabic, 3-15 parts mica powder, 2-12 parts polyethylene oxide, 0.5-2 parts sodium nitrite, and 2-30 parts gelatin.

[0005] Calcium and magnesium salts possess excellent hygroscopic properties. Their molecular structure is characterized by the fact that both calcium and magnesium ions are divalent cations with small ionic radii and high charge densities. This structural feature enables them to form strong hydration reactions with water molecules, attracting and binding them through electrostatic attraction. Most calcium and magnesium salts exhibit good water solubility, forming saturated solutions after absorbing moisture from the environment, further enhancing their sustained hygroscopic capacity. This dissolution process is exothermic, which helps maintain the continuous hygroscopic process. Many calcium and magnesium salts undergo a crystal structure transformation during hygroscopic absorption, changing from anhydrous salts to hydrated salts. This structural change provides stable binding sites for water molecules.

[0006] Gelatin is a protein derivative whose gel-forming mechanism is based on the physical cross-linking of molecular chains. Gelatin molecules contain a large number of glycine, proline, and hydroxyproline residues, which interact through hydrogen bonds and van der Waals forces. When a gelatin solution cools, the molecular chains rearrange to form a three-dimensional network structure. This network is stabilized by hydrogen bonds, enabling it to encapsulate and fix a large amount of water, forming a gel system with a certain strength.

[0007] Gum arabic is a complex polysaccharide compound. It is mainly composed of monosaccharide units such as arabinose, galactose, and uronic acid, forming a highly branched polysaccharide structure. Gum arabic forms a weak gel through intermolecular hydrogen bonds and electrostatic interactions. Its branched structure endows it with good water solubility and emulsifying properties.

[0008] Polyethylene oxide (PEO) is a synthetic polymer. The PEO molecular chain contains numerous ether bonds, which can form hydrogen bonds with water molecules. Through physical entanglement and hydrogen bonding, the PEO molecular chain forms a three-dimensional network, exhibiting gel-like properties.

[0009] Mica has a typical layered silicate structure with weak interlayer bonding, making it prone to interlayer slippage. The surface of mica powder particles is relatively inert, exhibiting low adhesion to most organic and inorganic substances, thus effectively reducing adhesion between the material and the mold during tableting. Mica powder typically has a flaky structure, which forms a lubricating layer at the contact surface during tableting, significantly reducing the coefficient of friction.

[0010] Nitrites are more readily converted to nitrites in acidic environments, the latter exhibiting stronger antibacterial activity. This pH dependence allows them to exert their optimal antifungal effect under specific conditions. As a moderately potent oxidizing agent, nitrites can oxidize key components of microbial cell membranes, disrupting cell membrane integrity and leading to microbial death.

[0011] In some embodiments, the calcium-magnesium salt is magnesium chloride or calcium chloride.

[0012] In some embodiments, the gelatin, gum arabic, and polyethylene oxide are gelling agents; mica powder is a tablet release agent; and sodium nitrite is a mildew inhibitor.

[0013] In some embodiments, the above-mentioned high hygroscopicity, water-free composite gel-type calcium magnesium salt tablets have the following weight parts of each raw material: 45-60 parts calcium magnesium salt, 20-25 parts gum arabic, 3-13.5 parts mica powder, 2-10 parts polyethylene oxide, 0.5 parts sodium nitrite, and 6-25 parts gelatin.

[0014] In some embodiments, the weight ratio of the calcium magnesium salt, gum arabic, and gelatin is (3-10):(1-4):1.

[0015] In some embodiments, the tablet has a diameter of 10-30 mm, a weight of 0.5-15 g, and a thickness of 2.0-7.5 mm.

[0016] In some embodiments, after the tablets are exposed to 35°C and 95%RH for 20 hours, the moisture absorption rate can reach 230%-300% and the tablets always maintain a gel state without liquid water precipitation.

[0017] In some embodiments, the mica powder has a particle size of 325-800 mesh, more preferably 400-600 mesh. At this fineness, the mica powder can uniformly fill the space between the calcium magnesium salt and the gel network, serving both as a lubricant for demolding and as a micro-scaffold support structure.

[0018] In some embodiments, the aspect ratio of the mica powder is 40-80, preferably 50-60. By limiting the aspect ratio of the mica powder, the planar orientation of the mica particles in the gel network forms a microscopic 'maze structure'. This not only significantly improves the mechanical strength of the tablet after moisture absorption (preventing disintegration), but also further locks in any free water that may be generated through physical barrier, creating a synergistic water-locking effect with the polymer gel network.

[0019] A method for preparing the above-mentioned high hygroscopicity, water-free composite gel-type calcium magnesium salt tablets, using a whole-tablet compression method, includes the following steps:

[0020] Step 1: According to the ingredient ratio, take calcium magnesium salt, gum arabic, and gelatin and pour them into a mixing container. Stir at 400-600 rpm until homogeneous. Step 2: According to the raw material composition ratio, take polyethylene oxide and sodium nitrite and pour them into the mixing container of Step 1 after mixing and stirring. Stir evenly at a speed of 800-1200 rpm. Step 3: Pour the mica powder into the mixing container from Step 2 after mixing and stirring, according to the raw material composition ratio, and stir evenly at a speed of 800-1200 rpm. Step 4: Pour the well-stirred raw materials into a dry granulator to form uniform granules, and then pour them into a tablet press for tableting.

[0021] In some embodiments, in step four, the granulation pressure is 30-50 bar, and the resulting particles have a fineness of 800-1200 mesh.

[0022] In some embodiments, the tableting pressure is 4-8 tons, and the resulting tablets have a hardness of not less than 100N.

[0023] The beneficial effects of this invention are: High hygroscopicity and gelation: This invention utilizes the synergistic effects of gelatin, gum arabic, and PEO to construct a three-dimensional network at the molecular level that is highly hydrophilic and also highly viscoelastic. The complexing and physical entanglement forces of the polymer chains on ions are used to achieve initial water locking. At the same time, the 'maze barrier' formed by high aspect ratio mica powder in the gel matrix greatly extends the penetration path of water molecules, thus achieving the technical effect that even under ultra-high hygroscopicity, the tablets can still maintain their shape and prevent liquid water from precipitating.

[0024] Excellent physical properties: In this invention, mica powder, as a layered silicate structure, plays a good role in lubrication and demolding during the tableting process, reduces the coefficient of friction, makes the tablet surface smooth and free of pits, and the hardness can reach more than 100N, which meets the needs of large-scale industrial production.

[0025] Long-lasting anti-mold and antibacterial effect: In this invention, sodium nitrite can interfere with the respiratory metabolism of microorganisms and damage cell membranes, exerting the best anti-mold effect under specific conditions, ensuring that the desiccant does not mold in humid environments. This composite gel-type calcium and magnesium salt tablet is suitable for use in the electronics and medical fields. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 These are photographs of the tablets in Example 1 before and after moisture absorption, where A is before moisture absorption and B is after moisture absorption.

[0028] Figure 2 These are photographs of the tablets in Example 5 before and after moisture absorption, where A is before moisture absorption and B is after moisture absorption.

[0029] Figure 3 These are photographs of the tablets in Example 6 before and after moisture absorption, where A is before moisture absorption and B is after moisture absorption.

[0030] Figure 4 The moisture absorption curves are for the tablets of Examples 1, 5, 6 and Comparative Examples 1, 11, 12, 13.

[0031] Figure 5 This is a diagram showing the results of an antibacterial experiment.

[0032] Figure 6 This is a photograph of the long-term stability test of the tablets in Example 7. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a 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 those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0034] Example 1 (Magnesium Chloride 45%) Preparation of a high-hygroscopic, water-free composite gel-type calcium and magnesium salt tablet Raw material formula: 45 parts magnesium chloride, 25 parts gum arabic, 6 parts gelatin, 13.5 parts mica powder, 10 parts polyethylene oxide, and 0.5 parts sodium nitrite. The mica powder has a particle size of 400-600 mesh and an aspect ratio of 50-60.

[0035] Preparation method: Pour magnesium chloride, gum arabic, and gelatin into a mixing container and stir at 500 rpm for 10 minutes. Add polyethylene oxide and sodium nitrite, and stir at 1000 rpm for 20 minutes; Add mica powder and stir at 1000 rpm for 5 minutes; Granulation was carried out using a dry granulation method at 40 bar pressure to a mesh size of 1000, and then compressed into tablets with a diameter of 10 mm, a weight of 0.5 g, and a thickness of 2.3 mm under a pressure of 6 tons.

[0036] The tablets were placed in a constant temperature and humidity chamber at 35 degrees Celsius and 95% humidity to test the moisture absorption rate, and then tested in a completely exposed environment for 20 hours.

[0037] The hardness test method was to use a YD-Ⅱ tablet hardness tester.

[0038] Test results: Moisture absorption rate 294.94%, hardness 200N, maintained gel state throughout, no liquid water produced, no mold growth.

[0039] Example 2 (Adjusting the ratio of gelatin to gum arabic) Raw material formula: 45 parts magnesium chloride, 20 parts gum arabic, 11 parts gelatin, 13.5 parts mica powder, 10 parts polyethylene oxide, and 0.5 parts sodium nitrite. Among them, the particle size of mica powder is 400-600 mesh, and the aspect ratio is 50-60.

[0040] The preparation and testing methods are the same as in Example 1. Tablets with a diameter of 12 mm, a weight of 0.5 g, and a thickness of 2.2 mm were prepared.

[0041] Results: Moisture absorption rate 232.5%, hardness 209.1 N, maintained gel state after moisture absorption and no liquid water.

[0042] Example 3 (Low-proportion Arabica tree scheme) Raw material formula: 45 parts magnesium chloride, 15 parts gum arabic, 16 parts gelatin, 13.5 parts mica powder, 10 parts polyethylene oxide, and 0.5 parts sodium nitrite.

[0043] The preparation and testing methods are the same as in Example 1. Tablets with a diameter of 12 mm, a weight of 0.5 g, and a thickness of 2.3 mm were prepared.

[0044] Results: The moisture absorption rate was 248.2%, the hardness was 144.1 N, and it maintained a gel state throughout, with no liquid water produced.

[0045] Example 4 Raw material formula: 45 parts magnesium chloride, 25 parts gum arabic, 24.5 parts gelatin, 3 parts mica powder, 2 parts polyethylene oxide, and 0.5 parts sodium nitrite. The mica powder has a particle size of 400-600 mesh and an aspect ratio of 50-60.

[0046] The preparation and testing methods are the same as in Example 1. Tablets with a diameter of 10 mm, a weight of 0.5 g, and a thickness of 2.4 mm were prepared.

[0047] Results: The moisture absorption rate was 299.1%, the hardness was 239.9 N, and it maintained a gel state throughout, with no liquid water produced.

[0048] Example 5 (Magnesium Chloride 50%) Raw material formula: 50 parts magnesium chloride, 25 parts gum arabic, 6 parts gelatin, 6.5 parts mica powder, 12 parts polyethylene oxide, and 0.5 parts sodium nitrite. The mica powder has a particle size of 400-600 mesh and an aspect ratio of 50-60.

[0049] The preparation and testing methods are the same as in Example 1. The tablets were compressed into tablets with a diameter of 10 mm, a weight of 0.5 g, and a thickness of 2.4 mm.

[0050] Results: The hardness was 200 N, the moisture absorption rate remained at 264.4%, and the gel state was maintained without the generation of liquid water.

[0051] Example 6 (Calcium Chloride 60%) Raw material formula: 60 parts calcium chloride, 25 parts gum arabic, 3 parts mica powder, 2 parts polyethylene oxide, 0.5 parts sodium nitrite, and 9.5 parts gelatin. The mica powder has a particle size of 400-600 mesh and an aspect ratio of 50-60.

[0052] The preparation and testing methods are the same as in Example 1. The tablets were compressed into tablets with a diameter of 30 mm, a weight of 15 g, and a thickness of 7.5 mm.

[0053] Results: The hardness was 400 N, the moisture absorption rate remained at 287.22%, and the gel state was maintained without the generation of liquid water.

[0054] Example 7 (Long-term stability test) Raw material formula: 45 parts magnesium chloride, 25 parts gum arabic, 6 parts gelatin, 13.5 parts mica powder, 10 parts polyethylene oxide, and 0.5 parts sodium nitrite. The mica powder has a particle size of 400-600 mesh and an aspect ratio of 50-60.

[0055] The preparation method is the same as in Example 1. The tablets are compressed into tablets with a diameter of 10 mm, a weight of 0.5 g, and a thickness of 2.6 mm.

[0056] The tablets were placed in a constant temperature and humidity chamber at 35 degrees Celsius and 95% humidity to test the moisture absorption rate. The tablets were then continuously tested in complete exposure to the environment for 35 days. Other tests were the same as in Example 1.

[0057] Results: The hardness was 200 N, the moisture absorption rate remained at 311.2%, and it maintained a gel state with no liquid water production (e.g., Figure 6 (As shown). The tablet's morphological integrity after being stored in a high-temperature and high-humidity environment for a longer period (35 days) demonstrates its superior durability compared to traditional products.

[0058] Comparative Example 1 (Traditional modified starch-based desiccant) Raw material formula: 50% magnesium chloride, 49% modified potato starch, 1% talc.

[0059] The preparation and testing methods are the same as in Example 1. The tablets were compressed into tablets with a diameter of 10 mm and a thickness of 3.5 mm.

[0060] Test results: The moisture absorption rate is only 157%, and the hardness is only 16.9 N. After absorbing moisture, it cannot maintain a gel state, and a large amount of flowable liquid water appears. This proves that the composite gel system of this invention (gum arabic + gelatin + PEO) is far superior to the traditional starch system in terms of water retention capacity.

[0061] Comparative Example 2 Compared to Example 4, polyethylene oxide and antifungal agent are missing.

[0062] Raw material formula: 45 parts magnesium chloride, 25 parts gum arabic, 25 parts gelatin, and 5 parts mica powder (PEO and sodium nitrite-free). The mica powder has a particle size of 400-600 mesh and an aspect ratio of 50-60.

[0063] The preparation and testing methods are the same as in Example 1. The tablets were compressed into tablets with a diameter of 10 mm and a thickness of 2.1 mm.

[0064] Test results: Moisture absorption rate 290.4%, hardness 265.5 N. Although the moisture absorption rate is high, the gel structure is loose, and obvious signs of mold growth appear on the surface. This demonstrates that polyethylene oxide (PEO) plays a crucial role in reinforcing the gel structure, and sodium nitrite plays a key role in preventing mold growth.

[0065] Comparative Example 3 (lacking gelatin component) Raw material formula: 45 parts magnesium chloride, 31 parts gum arabic, 13.5 parts mica powder, 10 parts polyethylene oxide, and 0.5 parts sodium nitrite. Among them, the particle size of mica powder is 400-600 mesh, and the aspect ratio is 50-60.

[0066] The preparation and testing methods are the same as in Example 1. The tablets were compressed into tablets with a diameter of 12 mm and a thickness of 2.2 mm.

[0067] Results: The hardness was 11.6 N and the moisture absorption rate was 251.2%, but it could not form a gel after absorbing moisture, resulting in glue separation.

[0068] Comparative Example 4 (lacking gum arabic component) Raw material formula: 45 parts magnesium chloride, 31 parts gelatin, 13.5 parts mica powder, 10 parts polyethylene oxide, and 0.5 parts sodium nitrite. Among them, the particle size of mica powder is 400-600 mesh, and the aspect ratio is 50-60.

[0069] The preparation and testing methods are the same as in Example 1. The tablets were compressed into tablets with a diameter of 12 mm, a weight of 0.5 g, and a thickness of 2.0 mm.

[0070] Results: Hardness 61.9 N, moisture absorption rate maintained at 232.4%, after moisture absorption, the gel bursts open from the inside out, accompanied by liquid water seepage.

[0071] Comparative Example 5 (lacking gum arabic and gelatin components) Raw material formula: 45 parts magnesium chloride, 13.5 parts mica powder, 10 parts polyethylene oxide, and 0.5 parts sodium nitrite. Among them, the particle size of mica powder is 400-600 mesh, and the aspect ratio is 50-60.

[0072] The preparation and testing methods are the same as in Example 1. The tablets were compressed into tablets with a diameter of 12 mm and a thickness of 2.1 mm.

[0073] Results: The hardness was 23.3 N, the moisture absorption rate remained at 211.1%, and no gel could be formed after moisture absorption, resulting in glue separation.

[0074] Proof: Gelatin and gum arabic must be used in combination to form a stable encapsulated gel network while maintaining high hardness.

[0075] Comparative Example 6 (using magnesium stearate instead of mica powder) Raw material formula: 45 parts magnesium chloride, 25 parts gum arabic, 6 parts gelatin, 13.5 parts magnesium stearate, 10 parts polyethylene oxide, and 0.5 parts sodium nitrite.

[0076] The preparation and testing methods are the same as in Example 1. The tablets were compressed into tablets with a diameter of 12 mm and a thickness of 2.2 mm.

[0077] Results: The moisture absorption rate remained at 255.1%, the hardness was only 61.2 N, and after absorbing moisture, it exhibited a gel-like structure that burst open from the inside out, with no liquid water generated around it.

[0078] Comparative Example 7 (using talc instead of mica powder) Raw material formula: 45 parts magnesium chloride, 25 parts gum arabic, 6 parts gelatin, 13.5 parts talc, 10 parts polyethylene oxide, and 0.5 parts sodium nitrite.

[0079] The preparation and testing methods are the same as in Example 1. The tablets were compressed into tablets with a diameter of 12 mm, a weight of 0.5 g, and a thickness of 2.3 mm.

[0080] Results: The hardness was 147.5 N, the moisture absorption rate remained at 248.3%, and glue separation occurred after moisture absorption, making it impossible to maintain the integrity of the shape.

[0081] Comparative Examples 6 and 7 demonstrate that the unique layered structure of mica powder not only plays a demolding role in dry granulation and high-pressure tableting, but also has a significant strengthening effect on the structural skeleton of tablets.

[0082] Comparative Example 8 (using sodium benzoate instead of sodium nitrite) Raw material formula: 45 parts magnesium chloride, 25 parts gum arabic, 6 parts gelatin, 11.5 parts mica powder, 10 parts polyethylene oxide, and 2 parts sodium benzoate. The mica powder has a particle size of 400-600 mesh and an aspect ratio of 50-60.

[0083] The preparation and testing methods are the same as in Example 1. The tablets were compressed into tablets with a diameter of 12 mm and a thickness of 2.1 mm.

[0084] Results: The hardness was 205.5 N, the moisture absorption rate remained at 245.6%, a gel-like structure was formed, no liquid water was produced, and the surface of the gel showed signs of mold growth and appeared as hair-like filaments.

[0085] Comparative Example 9 (less than 15 parts of gum arabic) Raw material formula: 45 parts magnesium chloride, 10 parts gum arabic, 21 parts gelatin, 13.5 parts mica powder, 10 parts polyethylene oxide, and 0.5 parts sodium nitrite. Among them, the particle size of mica powder is 400-600 mesh, and the aspect ratio is 50-60.

[0086] The preparation and testing methods are the same as in Example 1. The tablets were compressed into tablets with a diameter of 12 mm, a weight of 0.5 g, and a thickness of 2.2 mm.

[0087] Test results: Hardness was 12.4N, moisture absorption rate remained at 238.3%, gel was formed, but a small amount of liquid water appeared.

[0088] Comparative Example 10 (using cornstarch and carrageenan instead of gum arabic and gelatin) Raw material formula: 45 parts magnesium chloride, 25 parts raw starch, 6 parts carrageenan, 13.5 parts mica powder, 10 parts polyethylene oxide, and 0.5 parts sodium nitrite. Among them, the particle size of mica powder is 400-600 mesh, and the aspect ratio is 50-60.

[0089] The preparation and testing methods are the same as in Example 1. The tablets were compressed into tablets with a diameter of 12 mm and a thickness of 2.6 mm.

[0090] Results: The hardness was 0N, the moisture absorption rate remained at 141.2%, and the overall structure was a very loose gel.

[0091] Comparative Example 11 Traditional silica gel desiccant tablets Tests showed that the moisture absorption rate remained at 28%, and the product remained in a solid state with no liquid water produced.

[0092] Comparative Example 12 Traditional diatomaceous earth desiccant tablets Tests showed that the humidity remained at 15%, and the product remained in a solid state with no liquid water produced.

[0093] Comparative Example 13 Traditional fiber desiccant tablets Tests showed that the humidity remained at 31.5%, and the substance remained in a solid state with no liquid water produced.

[0094] The test results for each embodiment and comparative example are shown in Table 1. Table 1

[0095] Traditional desiccants (such as silica gel, diatomaceous earth, and fiber desiccants) typically have a moisture absorption rate that is difficult to exceed 40%. Although calcium and magnesium salts have extremely high theoretical moisture absorption capacity, the liquid water formed after their deliquescence is very easy to seep out, causing secondary pollution. This invention creatively employs a composite gel system composed of gelatin, gum arabic, and polyethylene oxide (PEO).

[0096] As shown in Table 1, compared with traditional silica gel and fiber desiccants (Comparative Examples 11 and 13), the moisture absorption rate of the embodiments of the present invention is increased by about 8-10 times. At the same time, compared with traditional starch-based desiccants (Comparative Example 1), the composite gel system of the present invention completely solves the problem of liquefaction and pollution after high moisture absorption, proving the excellent water-locking performance of the compound of gelatin, gum arabic and PEO.

[0097] Without gelatin (Comparative Example 3), the tablet hardness is only 11.6 N and the glue separates; without gum arabic (Comparative Example 4), the gel "crashes" after absorbing moisture, accompanied by the seepage of liquid water; without PEO (Comparative Example 2), the gel structure exhibits a noticeably loose texture. Only when the three components are used in combination in a specific ratio can a high moisture absorption rate (up to 299.1%) be maintained while simultaneously locking in moisture using a three-dimensional network structure, ensuring that no liquid water is generated throughout the process. This synergistic effect is not a simple additive effect of the components, but fundamentally solves the industry problem of high-salt tablets being unable to simultaneously achieve both "moisture absorption" and "water retention".

[0098] Replacing mica powder with conventional magnesium stearate (Comparative Example 6) or talc (Comparative Example 7) significantly reduced tablet hardness (to only 61.2 N-147.5 N), and tablets were prone to morphological damage or glue separation after absorbing moisture. The unique layered silicate structure of mica powder, during dry granulation and high-pressure tableting, forms a "reinforced concrete"-like structural framework with the gelling component. This not only endows the tablets with extremely high initial strength (up to 400 N), but also allows them to maintain their morphological integrity and prevent disintegration even after absorbing three times their own weight in water.

[0099] Antibacterial test To demonstrate the effectiveness of sodium nitrite in the tablet at the minimum addition amount of 0.5 parts and the maximum addition amount of 2 parts, two test samples (0.5% addition amount and 2% addition amount) and one control sample (0% addition amount) were placed on the surface of a culture dish containing solidified nutrient salt agar under aseptic conditions. The culture dishes containing the two test samples (0.5% addition amount and 2% addition amount) and the one control sample (0% addition amount) were placed in a constant temperature and humidity incubator and incubated for 7 days at a temperature of 25℃-30℃ and a relative humidity of not less than 85%. The two test samples and one control sample were then visually inspected.

[0100] The preparation methods for each sample are the same as in Example 1.

[0101] like Figure 5 As shown, after 7 days, the petri dishes of the control sample (0% addition) were covered with mold, while no mold was found in the test samples (0.5% addition and 2% addition).

[0102] Comparative experiment 8 and antibacterial experiments proved that sodium nitrite, through a specific oxidation mechanism, exhibits a broad-spectrum antibacterial activity superior to conventional antifungal agents (sodium benzoate) in the high-salt microenvironment of tablets, ensuring the long-term use of the product in high-temperature and high-humidity environments (no mold growth for 7 days).

[0103] In summary, this invention, through precise control of the proportions of each raw material component and optimization of the preparation process, successfully overcomes the technical defects of traditional calcium and magnesium salt desiccants, such as easy liquefaction, poor strength, and susceptibility to mold. The product of this invention has a moisture absorption rate of 230%-300% and maintains a stable gel state throughout, demonstrating significant practical value and technological advancement in humidity control applications in precision electronics, industrial equipment, and small, enclosed spaces.

[0104] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A composite gel-type calcium magnesium salt tablet with high hygroscopicity and no liquid water, characterized in that, It is made from the following raw materials in parts by weight: 45-70 parts calcium magnesium salt, 15-25 parts gum arabic, 3-15 parts mica powder, 2-12 parts polyethylene oxide, 0.5-2 parts sodium nitrite, and 2-30 parts gelatin.

2. The high hygroscopicity, water-free composite gel-type calcium magnesium salt tablet according to claim 1, characterized in that, The weight parts of each raw material are as follows: calcium magnesium salt 45-60 parts, gum arabic 20-25 parts, mica powder 3-13.5 parts, polyethylene oxide 2-10 parts, sodium nitrite 0.5 parts, and gelatin 6-25 parts.

3. The high hygroscopicity, water-free composite gel-type calcium magnesium salt tablet according to claim 1, characterized in that, The weight ratio of the calcium magnesium salt, gum arabic, and gelatin is (3-10):(1-4):

1.

4. The composite gel-type calcium magnesium salt tablet with high hygroscopicity and no liquid water according to claim 1, characterized in that: The calcium-magnesium salt is magnesium chloride or calcium chloride.

5. The high hygroscopicity, water-free composite gel-type calcium magnesium salt tablet according to claim 1, characterized in that: The gelatin, gum arabic, and polyethylene oxide are used as gelling agents; mica powder is used as a tablet release agent; and sodium nitrite is used as a mildew inhibitor.

6. The high hygroscopicity, water-free composite gel-type calcium magnesium salt tablet according to claim 1, characterized in that, The tablets have a diameter of 10-30 mm, a weight of 0.5-15 g, and a thickness of 2.0-7.5 mm.

7. The high hygroscopicity, water-free composite gel-type calcium magnesium salt tablet according to claim 1, characterized in that, After being exposed to 35°C and 95%RH for 20 hours, the tablets have a moisture absorption rate of 230%-300% and maintain a gel state without any liquid water precipitation.

8. A method for preparing a high-hygroscopicity, water-free composite gel-type calcium magnesium salt tablet as described in any one of claims 1 to 7, characterized in that, The whole-tablet compression method includes the following steps: Step 1: According to the ingredient ratio, take calcium magnesium salt, gum arabic, and gelatin and pour them into a mixing container. Stir at 400-600 rpm until homogeneous. Step 2: According to the raw material composition ratio, take polyethylene oxide and sodium nitrite and pour them into the mixing container of Step 1 after mixing and stirring. Stir evenly at a speed of 800-1200 rpm. Step 3: Pour the mica powder into the mixing container from Step 2 after mixing and stirring, according to the raw material composition ratio, and stir evenly at a speed of 800-1200 rpm. Step 4: Pour the well-stirred raw materials into a dry granulator to form uniform granules, and then pour them into a tablet press for tableting.

9. The preparation method according to claim 8, characterized in that: In step four, the granulation pressure is 30-50 bar, and the resulting granules have a fineness of 800-1200 mesh.

10. The preparation method according to claim 9, characterized in that: During tableting, the compression pressure is 4-8 tons, and the resulting tablets have a hardness of not less than 100N.

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