Humidity control material and humidity control member

Abstract

A humidity control material according to the present disclosure is characterized by comprising: a first humidity control component that absorbs or releases moisture; and a water-absorbing body containing a water-absorbing material, wherein the first humidity control component is sodium propionate. Alternatively, the humidity control material is characterized in that the first humidity control component includes at least one selected from the group consisting of sodium propionate, sodium formate, potassium formate, and potassium acetate.

Description

Humidity-conditioning materials and humidity-conditioning components

[0001] This application claims priority to Japanese Patent Application No. 2023-186039, filed on October 31, 2023, the contents of which are incorporated herein by reference.

[0002] Hygroscopic compositions have been disclosed in the past.

[0003] For example, Patent Document 1 uses sodium acetate and / or potassium acetate, which are non-halogen inorganic salts, in a hygroscopic composition to provide a hygroscopic composition that is inexpensive, has high hygroscopicity, and is highly safe with little risk of metal rust or the like.

[0004] Japanese Patent Application Laid-Open No. 2000-005550

[0005] However, the acetate salts described above pose safety concerns because they promote corrosion in iron pieces that do not have a corrosion-resistant film or whose corrosion-resistant film has peeled off or thinned, particularly in high humidity environments with a relative humidity of 70% or more.

[0006] In view of the above problems, the present disclosure aims to provide a humidity-conditioning material and humidity-conditioning member that have improved low corrosion resistance against rust and have a high humidity-conditioning function by absorbing or releasing moisture.

[0007] A humidity-conditioning material according to a first aspect of the present disclosure comprises a first humidity-conditioning component that absorbs or releases moisture, and a water-absorbing body containing a water-absorbing material, and is characterized in that the first humidity-conditioning component is sodium propionate.

[0008] A humidity-conditioning material according to a second aspect of the present disclosure comprises a first humidity-conditioning component that absorbs or releases moisture, and a water-absorbing body that contains a water-absorbing material, and is characterized in that the first humidity-conditioning component contains at least one selected from the group consisting of sodium propionate, sodium formate, potassium formate, and potassium acetate.

[0009] A humidity control member according to a third aspect of the present disclosure is characterized by comprising the humidity control material according to the first or second aspect of the present disclosure and a support that supports the humidity control material.

[0010] As described above, according to the present disclosure, it is possible to provide a humidity-conditioning material and a humidity-conditioning member that have improved anti-corrosion properties and a high humidity-conditioning function by absorbing or releasing moisture.

[0011] FIG. 1 is a cross-sectional view schematically showing a humidity conditioner according to the present disclosure. FIG. 2 is a view showing moisture absorption isotherms. FIG. 3 is a view showing moisture absorption isotherms. FIG. 4 is a view showing the moisture absorption rate when a water-absorbent resin and a first humidity-conditioning component and / or a second humidity-conditioning component are provided. FIG. 5 shows the results of a corrosion test. FIG. 6 is a view showing a humidity conditioner according to the present disclosure, showing a humidity conditioner in which a humidity conditioner is dispersed in a nonwoven fabric. FIG. 7 is a view showing a humidity conditioner according to the present disclosure, showing a humidity conditioner in which a humidity conditioner is provided between nonwoven fabrics. FIG. 8 is a view showing a humidity conditioner according to the present disclosure, showing a humidity conditioner in which a humidity conditioner is provided on the surface of a breathable substrate. FIG. 9 is a cross-sectional view schematically showing a humidity conditioner according to the present disclosure. FIG. 10 is a view showing moisture absorption isotherms for samples from Examples 1 to 5. FIG. 11A is a view showing moisture absorption isotherms for sodium propionate, sodium carbonate, and the sample of Example 1. FIG. 11B is a diagram showing moisture sorption isotherms for sodium formate, sodium carbonate, and the sample of Example 3. FIG. 11C is a diagram showing moisture sorption isotherms for potassium formate, sodium carbonate, and the sample of Example 4. FIG. 11D is a diagram showing moisture sorption isotherms for potassium acetate, potassium carbonate, and the sample of Example 5. FIG. 12 is a diagram schematically illustrating a corrosion test method. FIG. 13A is an image showing the results of a corrosion test for the sample of Example 6. FIG. 13B is an image showing the results of a corrosion test for the sample of Example 7. FIG. 13C is an image showing the results of a corrosion test for the sample of Example 8. FIG. 13D is an image showing the results of a corrosion test for the sample of Example 9. FIG. 13E is an image showing the results of a corrosion test for the sample of Comparative Example 1. FIG. 13F is an image showing the results of a corrosion test for the sample of Comparative Example 2. FIG. 14 is a diagram schematically illustrating a humidity control member according to the present disclosure, showing a humidity control member in which a humidity conditioner is dispersed in a nonwoven fabric. Fig. 15 is a diagram schematically illustrating a humidity control member according to the present disclosure, in which a humidity control material is provided between nonwoven fabrics. Fig. 16 is a diagram schematically illustrating a humidity control member according to the present disclosure, in which a humidity control material is provided on the surface of a breathable substrate.

[0012] Preferred embodiments of the present disclosure will be described in detail below with reference to the drawings. Note that the embodiments described below do not unduly limit the content of the present disclosure set forth in the claims, and not all of the configurations described in the embodiments are necessarily essential as means for solving the problems of the present disclosure.

[0013] 1 First Embodiment [Humidity Conditioning Material] Fig. 1 is a cross-sectional view schematically showing a humidity conditioner 10 according to the present disclosure. As shown in Fig. 1, the humidity conditioner 10 according to the present disclosure comprises a first humidity conditioner component 1 and a water absorbent body 3 containing a water absorbent material. The first humidity conditioner component 1 is characterized by being sodium propionate.

[0014] Because deliquescent metal salts have a very large moisture absorption capacity, humidity regulators combined with water-absorbing materials are used. Furthermore, deliquescent metal salts are generally highly corrosive, but carboxylates are recognized as being relatively less corrosive. Representative carboxylates include sodium formate and sodium acetate, but they cause rust in high-temperature, high-humidity environments, especially under acidic conditions of pH 7 or less, on iron without a corrosion-resistant film.

[0015] The humidity conditioner 10 according to the present disclosure has a first humidity control component 1 that is sodium propionate, which improves low corrosiveness and provides a high humidity control function by absorbing or releasing moisture. Each component of the humidity conditioner 10 according to the present disclosure will be described below.

[0016] The first humidity control component 1 absorbs or releases moisture.

[0017] The humidity conditioner 10 adjusts the amount of moisture contained in the air. The humidity conditioner 10 also has the property of absorbing (moisture absorption) moisture when the surrounding relative humidity is relatively high compared to the equilibrium humidity, and conversely, releasing (moisture desorption) moisture when the surrounding relative humidity is relatively low. Unlike desiccants such as type A silica gel and zeolite, the humidity conditioner 10 repeatedly absorbs and desorbs moisture, so in principle it is effective semi-permanently.

[0018] As shown in Figure 1, humidity conditioner 10 includes a water-absorbing material containing a resin and / or a clay mineral, and a first humidity-conditioning component 1 that has a deliquescence point at a relative humidity of 50 to 60% and absorbs or releases moisture to provide humidity control. In addition to first humidity-conditioning component 1, humidity conditioner 10 may also include a second humidity-conditioning component 2, which is a sodium salt that has a deliquescence point at a relative humidity of 60 to 90% and can increase the amount of moisture absorbed at higher humidities. The water-absorbing material can retain either first humidity-conditioning component 1 or second humidity-conditioning component 2. Humidity conditioner 10 absorbs and absorbs moisture contained in the air in the environment where it is placed, or releases and releases moisture contained in humidity conditioner 10 into the air, depending on the humidity of the environment.

[0019] Here, "humidity control" means adjusting the relative humidity of the surrounding air to approach the equilibrium humidity band of the humidity conditioner 10. Specifically, for example, assuming that the equilibrium humidity of the humidity conditioner 10 is 50% RH, when the relative humidity of the surrounding air is higher than 50% RH, the humidity conditioner 10 absorbs (absorbs) moisture, and when the relative humidity of the surrounding air is lower than 50% RH, the humidity conditioner 10 releases (desorbs) moisture. Typically, the predetermined relative humidity band correlates with the material of the humidity conditioner 10. Specifically, for example, the predetermined relative humidity band correlates with the ratio of the amount of moisture contained in the humidity conditioner 10 to the first humidity control component 1 and the second humidity control component 2.

[0020] The first humidity-conditioning component 1 and the second humidity-conditioning component 2 may be held not only by the water-absorbing material but also by a support 20 that supports the humidity-conditioning material 10. The support 20 will be described later.

[0021] As described above, the first humidity-regulating component 1 is sodium propionate, which improves the low corrosiveness and provides a high humidity-regulating function by absorbing or releasing moisture.

[0022] The first humidity-conditioning component 1 and the second humidity-conditioning component 2 may be present in the water-absorbing material described later, or may be present separately and mixed together.

[0023] The water-absorbing material has the function of retaining the first humidity-conditioning component 1 and the second humidity-conditioning component 2. Because the water-absorbing material retains the first humidity-conditioning component 1 and the second humidity-conditioning component 2, it is possible to realize a humidity-conditioning material 10 with a high ratio of surface area to volume. This makes it possible to increase the rate of moisture absorption or release. Therefore, it is possible to obtain a humidity-conditioning material 10 with a high humidity-conditioning rate. Furthermore, it is preferable that the water-absorbing material be in powder or particulate form.

[0024] The water-absorbing material preferably contains at least one selected from the group consisting of water-absorbent resins (particles, powder) and clay minerals. This allows the water-absorbing material to favorably retain the first humidity-conditioning component 1 or the second humidity-conditioning component 2, thereby further enhancing the humidity-conditioning effect.

[0025] Specific examples of the water-absorbent resin material include ionic resins and nonionic resins. Examples of the ionic resin include alkali metal salts of polyacrylic acid (such as sodium polyacrylate) and starch-acrylate graft polymers, with alkali metal salts of polyacrylic acid being preferred. Specific examples of alkali metal salts of polyacrylic acid include sodium polyacrylate. Examples of the nonionic resin include vinyl acetate copolymers, maleic anhydride copolymers, polyvinyl alcohol, and polyalkylene oxides.

[0026] Specific examples of clay minerals include silicate minerals such as smectite, sepiolite, attapulgite, kaolinite perlite, and dolomite, and zeolites.

[0027] When the first humidity-conditioning component 1 and the second humidity-conditioning component 2 are present, the weight ratio of their total weight to the water-absorbing material is preferably 1:2 to 10:1, and more preferably 1:1 to 3:1. In this way, the amounts of the water-absorbing material and the first humidity-conditioning component 1 become appropriate, and the humidity-conditioning function can be further improved. Furthermore, if the proportion of the first humidity-conditioning component 1 is too high, there is a high risk of syneresis in the high humidity range, and if the proportion of the first humidity-conditioning component 1 is too low, the humidity-conditioning moisture content may be reduced.

[0028] The humidity-conditioning material 10 may be in the form of a powder, particles, or block, or may be used by supporting the humidity-conditioning component and water-absorbing material on a breathable substrate so that it can be efficiently brought into contact with air.

[0029] The second humidity-conditioning component 2 is preferably a sodium salt having a deliquescence point within a range of 60 to 90% RH. This allows a high humidity-conditioning water content to be maintained, particularly in an environment with a relative humidity of 60 to 90%. The second humidity-conditioning component 2 is preferably at least one selected from the group consisting of sodium acetate and sodium carbonate. This allows an even higher humidity-conditioning water content to be maintained.

[0030] The humidity-conditioning material 10 according to the present disclosure preferably further comprises a pH adjuster when it is necessary to suppress odor generation due to acid liberation from the humidity-conditioning component. The pH adjuster preferably exhibits alkaline properties by itself. The pH adjuster preferably contains a carbonate, and among these, a sodium salt is particularly preferred, as it does not significantly affect the humidity-conditioning properties of the first humidity-conditioning component 1 or the second humidity-conditioning component 2. If the sodium salt is used, even if ion exchange occurs with the humidity-conditioning component, the exchange is between sodium ions, so the effect on the humidity-conditioning properties is small.

[0031] Next, the moisture absorption characteristics of the humidity conditioner 10 of the present disclosure will be described.

[0032] FIG. 2 is a diagram showing moisture absorption isotherms, illustrating the moisture absorption rate versus relative humidity. The moisture absorption rate is calculated as (weight of absorbed moisture) / (weight of humidity-conditioning component) × 100. The samples used were sodium formate, sodium propionate, calcium chloride, and silica gel B. The samples used were sodium formate and a water-absorbent resin, sodium propionate and a water-absorbent resin, sodium formate, sodium propionate, calcium chloride, and silica gel B. As shown in FIG. 2, the samples using sodium propionate and sodium formate deliquesced at a relative humidity of 50-60%, with the deliquescent humidity being the threshold. In higher humidity environments, the samples used sodium propionate and a water-absorbent resin, and sodium formate and a water-absorbent resin maintained their threshold characteristics even after mixing with the water-absorbent resin. Therefore, when sodium formate or sodium propionate is selected as the first humidity-controlling component 1, it absorbs a large amount of moisture in a high-humidity environment of 60% or more relative humidity and can be regenerated in a dry state of 50% or less relative humidity without artificial heating. Therefore, by absorbing moisture during times when the temperature is low and the relative humidity is high, for example, at night or early in the morning, and then regenerating during the daytime when the temperature rises and the relative humidity is relatively low, the amount of moisture absorbed and released during the day-night cycle is significantly increased, preventing condensation.

[0033] On the other hand, the amount of moisture absorbed and released is very small in the case of using silica gel B. Also, the case of using calcium chloride as the first humidity-regulating component has a high moisture absorption rate even in a low relative humidity range, and for example, even at a relative humidity of 30%, the moisture absorption rate exceeds 100%, making it difficult to release moisture and dry, and has a low regeneration ability.

[0034] As described above, the combination of sodium propionate and a water-absorbent resin, and the combination of sodium formate and a water-absorbent resin are excellent in terms of humidity control properties because they can obtain a large humidity control capacity when the ambient humidity environment changes. On the other hand, the low corrosiveness of sodium formate and sodium propionate will be described later.

[0035] Figure 3 also shows moisture absorption isotherms. Figure 3 shows sodium formate, sodium propionate, sodium acetate, ammonium nitrate, and sodium carbonate as deliquescent salts with threshold characteristics. As shown in Figure 3, the samples using sodium formate and sodium propionate deliquesced (absorbed moisture) at 50-60% RH. Furthermore, the samples using ammonium nitrate deliquesced (absorbed moisture) at 60-70% RH, and the samples using sodium acetate and sodium carbonate deliquesced (absorbed moisture) at 70-80% RH.

[0036] Next, the moisture absorption rate of a humidity-conditioning material containing a first humidity-conditioning component and a second humidity-conditioning component will be described.

[0037] Fig. 4 is a diagram showing the moisture absorption rate when a water-absorbent resin and a first humidity-conditioning component and / or a second humidity-conditioning component are provided. Fig. 4 shows the moisture absorption rates for compositions 1 to 6. Each composition is as shown in Table 1 below. For composition 1, sodium formate was used as the first humidity-conditioning component for reference. Furthermore, for compositions 2 to 6, sodium propionate was used as the first humidity-conditioning component, and sodium acetate, sodium carbonate, and ammonium nitrate were used as the second humidity-conditioning component. Note that a water-absorbent resin was used in all compositions.

[0038]

[0039] As shown in Table 1 and FIG. 4, the composition using sodium propionate as the first humidity-conditioning component and sodium carbonate as the second humidity-conditioning component (composition 3) and the composition using sodium acetate (compositions 4 and 5) showed improved moisture absorption rates compared to the composition using sodium propionate alone.

[0040] On the other hand, the one using sodium propionate as the first humidity-conditioning component and ammonium nitrate (composition 6) as the second humidity-conditioning component had a lower moisture absorption rate than the one using sodium propionate alone. Note that the one using the water-absorbent resin alone had a lower moisture absorption rate than the one using sodium propionate alone.

[0041] Therefore, the second humidity-conditioning component is preferably a sodium salt having a deliquescence point within the range of 60 to 90% RH. Furthermore, at least one selected from the group consisting of sodium acetate and sodium carbonate is preferred. This is thought to be because, if the second humidity-conditioning component is the same sodium salt as sodium propionate, the humidity-conditioning properties are less affected even if ion exchange occurs between the components, and the amount of moisture absorbed in the high humidity range can be increased without impairing the threshold properties of sodium propionate.

[0042] Next, the results of the corrosion test on the sample in which the first humidity-conditioning component, the second humidity-conditioning component, and the water-absorbent resin were mixed will be described.

[0043] 5 shows the results of a corrosion test. The test involved contacting a sample containing a first humidity-conditioning component, a second humidity-conditioning component, and a water-absorbent resin with an iron piece. The samples included sodium formate (first humidity-conditioning component), sodium acetate (first humidity-conditioning component), sodium propionate (first humidity-conditioning component), a mixture of sodium propionate (first humidity-conditioning component) and sodium acetate (second humidity-conditioning component) in a weight ratio of 5:5, a mixture of sodium carbonate (first humidity-conditioning component), sodium formate (first humidity-conditioning component) and a water-absorbent resin in a weight ratio of 0.4:0.6, a mixture of sodium propionate (first humidity-conditioning component) and a water-absorbent resin in a weight ratio of 0.4:0.6, and a mixture of sodium propionate (first humidity-conditioning component), sodium acetate (second humidity-conditioning component), sodium carbonate (pH adjuster), and a water-absorbent resin in a weight ratio of 1.6:1.6:0.8:0.6.

[0044] The symbol ◯ indicates that the sample was less corrosive and had excellent anti-corrosion properties, the symbol × indicates that the sample was highly corrosive and did not have excellent anti-corrosion properties, and the symbol △ indicates that the sample was somewhat corrosive and had somewhat poor anti-corrosion properties.

[0045] As a result, as shown in Figure 5, the samples using sodium propionate (first humidity-conditioning component), sodium carbonate (first humidity-conditioning component), and sodium propionate (first humidity-conditioning component) and a water-absorbent resin did not corrode the iron pieces, and therefore had low corrosiveness and excellent rust safety. In addition, the samples using sodium propionate (first humidity-conditioning component) and sodium acetate (second humidity-conditioning component), and sodium propionate (first humidity-conditioning component), acetic acid (second humidity-conditioning component), sodium carbonate (pH adjuster), and a water-absorbent resin also had low corrosiveness and excellent rust safety.

[0046] On the other hand, the samples using sodium formate, sodium acetate, and sodium formate with water-absorbent resin corroded the iron pieces, which resulted in high corrosiveness and poor rust safety.

[0047] Therefore, in terms of low corrosiveness, the results show that the compositions using sodium propionate as the first humidity-conditioning component, sodium propionate as the first humidity-conditioning component and sodium acetate as the second humidity-conditioning component, and sodium carbonate as the first humidity-conditioning component or pH adjuster are excellent.

[0048] From the above results of water absorption and low corrosiveness, it was found that humidity-conditioning materials that had excellent water absorption and low corrosiveness were those that used sodium propionate as the first humidity-conditioning component, and more preferably humidity-conditioning materials that contained sodium propionate as the first humidity-conditioning component and a sodium salt having a deliquescence point in the range of 60 to 90% RH as the second humidity-conditioning component, or humidity-conditioning materials that contained sodium propionate as the first humidity-conditioning component and at least one selected from the group consisting of sodium acetate as the second humidity-conditioning component and sodium carbonate as the pH adjuster.

[0049] It has been explained that the humidity conditioner according to the present disclosure preferably further comprises a pH adjuster, which will be described in more detail below.

[0050] Table 2 shows the acid dissociation constant, hydrolysis constant, vapor pressure, and odor of formic acid and propionic acid. As shown in Table 2, propionic acid has a larger acid dissociation constant than formic acid and is more easily liberated. While formic acid has no odor, propionic acid has an extremely low odor threshold and has a slight odor.

[0051]

[0052] When the water-absorbing material is an ionic resin, protons are supplied to the resin, causing it to become acidic, and propionic acid above the odor threshold becomes advantageous. Therefore, it is preferable that the humidity-conditioning material further comprises a pH adjuster to further reduce odor. By adjusting the pH to the alkaline side with the pH adjuster, the advantage of propionic acid can be suppressed and the odor can be improved. Therefore, it is preferable that the pH adjuster be one that can adjust the pH to the alkaline side.

[0053] Table 3 shows whether the pH and odor were improved when sodium propionate was used as the first humidity-conditioning component, sodium acrylate as the water-absorbent resin, and potassium carbonate, sodium carbonate, calcium carbonate, or dipotassium hydrogen phosphate as the pH adjuster.

[0054]

[0055] As shown in Table 3, when the pH adjuster was potassium carbonate, sodium carbonate, or dipotassium hydrogen phosphate, the odor was improved, and potassium carbonate and sodium carbonate showed significant improvements at relatively low concentrations. Furthermore, the pH shifted to the alkaline side. Potassium carbonate showed significant improvement at concentrations of 4.0 wt.% or more, and sodium carbonate showed significant improvement at concentrations of 8.0 wt.% or more.

[0056] On the other hand, when calcium carbonate was used as a pH adjuster, no improvement in odor was observed. This is thought to be due to the low water solubility of calcium carbonate. Furthermore, dipotassium hydrogen phosphate did not improve odor unless the concentration was increased to 30.0 or higher.

[0057] Therefore, the pH adjuster preferably contains at least a carbonate, and more preferably a sodium salt, which does not significantly affect the humidity control properties of the first humidity control component 1 or the second humidity control component 2. Note that a pH adjuster that is not ionic may also be used.

[0058] As described above, the humidity-conditioning material according to the present disclosure has improved anti-corrosive properties and has a high humidity-conditioning function by absorbing or releasing moisture.

[0059] [Humidity Conditioning Member] Fig. 6 is a diagram schematically illustrating a humidity control member 100 according to the present disclosure, which is a diagram illustrating the humidity control member 100 in which the humidity control material 10 is dispersed in a nonwoven fabric. As shown in Fig. 6, the humidity control member 100 according to the present disclosure includes the humidity control material 10 described above and a support 20 that supports the humidity control material 10.

[0060] Furthermore, as shown in Fig. 6, the humidity control member 100 according to the present disclosure may have a support 20 made of nonwoven fabric, with the humidity conditioner 10 dispersed throughout the nonwoven fabric. Nonwoven fabric is preferable because of its high water vapor permeability. Therefore, the humidity control member 100 shown in Fig. 6 can have a high surface area-to-volume ratio, which can increase the rate of moisture absorption or release. Note that the support 20 may be made of hydrophilic fibers such as porous materials or woven fabrics, in addition to nonwoven fabrics.

[0061] The humidity conditioner 10 may be adhered to the surface of the support 20 with a binder or the like. On the other hand, if the water-absorbing material can also serve as a binder, no binder is necessary.

[0062] FIG. 7 is a schematic diagram of a humidity control member 100 according to the present disclosure, showing the humidity control member 100 in which the humidity control material 10 is provided between nonwoven fabrics. The humidity control member 100 according to the present disclosure may be in the form of a sheet. As shown in FIG. 7 , the humidity control member 100 according to the present disclosure may have a support 20 made of nonwoven fabric, with the humidity control material 10 provided between the nonwoven fabrics. The humidity control material 10 may be bonded to the support 20 by a binder 30 dispersed therein. The sheet may be made flame-retardant by mixing flame-retardant fibers into the nonwoven fabric. Furthermore, the first humidity control component 1 and the second humidity control component 2 may be present within the water absorbent body 3, or may be present separately and mixed together.

[0063] FIG. 8 is a schematic diagram of a humidity control member 100 according to the present disclosure, showing a humidity control member in which a humidity control material 10 is provided on the surface or inside of a breathable substrate. As shown in FIG. 8, the humidity control member according to the present disclosure may have a support 20 as a breathable substrate, and the humidity control material 10 may be provided on the surface or inside of the breathable substrate. As the breathable substrate, a pleated structure, a honeycomb structure, or the like is preferred. In this way, the surface area in contact with air is increased, thereby improving the humidity control function.

[0064] As described above, according to the present disclosure, it is possible to provide the humidity conditioner 10 and humidity conditioner member 100 that have improved anti-corrosion properties and have a high humidity control function by absorbing or releasing moisture.

[0065] 2 Second Embodiment [Humidity Conditioner] Fig. 9 is a cross-sectional view schematically showing a humidity conditioner 200 according to the present disclosure. As shown in Fig. 9, the humidity conditioner 200 according to the present disclosure comprises a first humidity conditioner component 211 and a water absorbent body 214 containing a water absorbent material. The first humidity conditioner component 211 is characterized by containing at least one selected from the group consisting of sodium propionate, sodium formate, potassium formate, and potassium acetate.

[0066] Sodium propionate, sodium formate, potassium formate, and potassium acetate have very high moisture absorption capacity and are deliquescent, so they are used as humidity adjusters in combination with water-absorbing materials to prevent liquid leakage. Sodium propionate has low corrosiveness. The corrosiveness of sodium formate, potassium formate, and potassium acetate can be further reduced by adding a pH adjuster, etc.

[0067] The humidity-conditioning material 200 according to the present disclosure has a first humidity-conditioning component 211 that contains at least one selected from the group consisting of sodium propionate, sodium formate, potassium formate, and potassium acetate, and therefore exhibits low corrosiveness and high humidity-conditioning function by absorbing or releasing moisture. Each component of the humidity-conditioning material 200 according to the present disclosure will be described below.

[0068] The first humidity control component 211 absorbs or releases moisture.

[0069] The humidity conditioner 200 adjusts the amount of moisture contained in the air. The humidity conditioner 200 has the property of absorbing (moisture absorption) moisture when the surrounding relative humidity is relatively high compared to the equilibrium humidity, and conversely, releasing (moisture desorption) moisture when the surrounding relative humidity is relatively low. Unlike desiccants such as type A silica gel and zeolite, which require heating or the like to desorb moisture, the humidity conditioner 200 repeatedly absorbs and desorbs moisture, and therefore, in principle, is effective semi-permanently.

[0070] As shown in FIG. 9 , humidity-conditioning material 200 includes a water-absorbent material containing a resin and / or a clay mineral, and a first humidity-conditioning component 211 that has a deliquescence point at a relative humidity of 60% or less and absorbs or releases moisture to exhibit humidity-conditioning function. In addition to first humidity-conditioning component 211, humidity-conditioning material 200 may also include a second humidity-conditioning component 212, which has a deliquescence point at a relative humidity of 60% to 90% and can increase the amount of moisture absorbed at higher humidity. The water-absorbent material can retain first humidity-conditioning component 211 or second humidity-conditioning component 212. Depending on the humidity of the environment in which it is placed, humidity-conditioning material 200 absorbs moisture contained in the air at that location to absorb moisture, or releases moisture contained in humidity-conditioning material 200 into the air to release moisture.

[0071] Note that "humidity control" means adjusting the relative humidity of the ambient air so that it approaches the equilibrium humidity band of the humidity control material 200. Specifically, for example, if the equilibrium humidity of the humidity control material 200 is 50% RH, when the relative humidity of the ambient air is higher than 50%, the humidity control material 200 absorbs (absorbs) moisture, and when the relative humidity of the ambient air is lower than 50%, the humidity control material 200 releases (desorbs) moisture. Typically, the equilibrium humidity band of the humidity control material 200 correlates with the material of the humidity control material 200. Specifically, for example, the equilibrium humidity band of the humidity control material 200 correlates with the amount of moisture contained in the humidity control material 200 relative to the first humidity control component 211 and the second humidity control component 212.

[0072] The first humidity-conditioning component 211 and the second humidity-conditioning component 212 may be held not only in the water-absorbing material but also in a support that supports the humidity-conditioning material 200. The support will be described later.

[0073] As described above, the first humidity-conditioning component 211 contains at least one selected from the group consisting of sodium propionate, sodium formate, potassium formate, and potassium acetate. In this way, the humidity-conditioning material 200 exhibits only low corrosiveness and exhibits a high humidity-conditioning function by absorbing or releasing moisture.

[0074] The first humidity control component 211 and the second humidity control component 212 may be present in a water-absorbing material described later, or may be mixed with each other without being present in a water-absorbing material.

[0075] The water-absorbing material has the function of retaining the first humidity-conditioning component 211 and the second humidity-conditioning component 212. If the material is composed only of the humidity-conditioning component 211 and the second humidity-conditioning component 212, it will become liquid upon deliquescing and spread out flatly, whereas the water-absorbing material retains the first humidity-conditioning component 211 and the second humidity-conditioning component 212, making it possible to realize a humidity-conditioning material 200 with a high surface area-to-volume ratio. This makes it possible to increase the rate of moisture absorption or release. This makes it possible to realize a humidity-conditioning material 200 with a high humidity-conditioning rate. Furthermore, the water-absorbing material is preferably in powder or particulate form.

[0076] The water-absorbing material preferably contains at least one selected from the group consisting of water-absorbing resins (particles, powder) and clay minerals, which allows the water-absorbing material to favorably retain the first humidity-conditioning component 211 or the second humidity-conditioning component 212, thereby further enhancing the humidity-conditioning effect.

[0077] Specific examples of the water-absorbent resin material include ionic resins and nonionic resins. Examples of ionic resins include alkali metal salts of polyacrylic acid (sodium polyacrylate, etc.), starch-acrylate graft polymers, etc., with alkali metal salts of polyacrylic acid being preferred. Specific examples of alkali metal salts of polyacrylic acid include sodium polyacrylate. Examples of nonionic resins include vinyl acetate copolymers, maleic anhydride copolymers, polyvinyl alcohol, polyalkylene oxides, etc.

[0078] Specific examples of clay minerals include silicate minerals such as smectite, sepiolite, attapulgite, kaolinite perlite, and dolomite, and zeolites.

[0079] When the humidity-conditioning material 200 has the first humidity-conditioning component 211 and the second humidity-conditioning component 212, the weight ratio of their total weight to the water-absorbent material is preferably 1:2 to 10:1, and more preferably 1:1 to 3:1. In this way, the amounts of the water-absorbent material and the first humidity-conditioning component 211 become appropriate, and the humidity-conditioning function can be further improved. Furthermore, if the proportion of the first humidity-conditioning component 211 is too high, the risk of syneresis in high humidity ranges may increase, and if the proportion of the first humidity-conditioning component 211 is too low, the humidity-conditioning moisture content may decrease.

[0080] The humidity-conditioning material 200 may be in the form of a powder, particles, block, etc., and the humidity-conditioning material 200 may be used by supporting the humidity-conditioning component and water-absorbing material on a breathable substrate so that it can efficiently come into contact with air.

[0081] The second humidity-conditioning component 212 is preferably a sodium salt having a deliquescence point in the range of 60 to 90% RH. This allows the humidity-conditioning material 200 to maintain a high humidity-conditioning moisture content, particularly in an environment with a relative humidity of 60 to 90% RH. The second humidity-conditioning component 212 is preferably at least one selected from the group consisting of sodium acetate and sodium carbonate. This allows the humidity-conditioning material 200 to maintain an even higher humidity-conditioning moisture content.

[0082] The humidity-conditioning material 200 according to the present disclosure preferably further comprises a pH adjuster 213 when it is necessary to suppress corrosion due to acid liberation from the humidity-conditioning component. The humidity-conditioning material 200 according to the present disclosure also preferably comprises a pH adjuster 213 when it is necessary to suppress odor generation due to acid liberation from the humidity-conditioning component. The pH adjuster 213 preferably exhibits alkaline properties by itself. The pH adjuster 213 preferably contains a carbonate that is non-corrosive, does not volatilize harmful components, and is highly safe. Among these, when the first humidity-conditioning component 211 or the second humidity-conditioning component 212 is a sodium salt, it is particularly preferable that the sodium salt does not significantly affect the humidity-conditioning properties of the first humidity-conditioning component 211 or the second humidity-conditioning component 212. If the humidity-conditioning component and the pH adjuster 213 are sodium salts, even if ion exchange occurs between the humidity-conditioning component and the pH adjuster 213, the exchange is between sodium ions, and therefore the effect on the humidity-conditioning properties is small.

[0083] Next, the moisture absorption characteristics of the humidity conditioner 200 of the present disclosure will be described.

[0084] 10 is a diagram showing moisture absorption isotherms for the samples of Examples 1 to 5, showing the moisture absorption rate versus relative humidity. The moisture absorption rate is expressed as (weight of absorbed moisture) / (weight of moisture-free humidity-conditioning material) × 100. The samples of Examples 1 to 5 were the following mixtures.

[0085] Example 1: A mixture of sodium propionate as the first humidity-conditioning component 211, sodium carbonate as the pH adjuster 213, and sodium polyacrylate as a water-absorbing resin; Example 2: A mixture of sodium propionate as the first humidity-conditioning component 211, sodium acetate as the second humidity-conditioning component 212, sodium carbonate as the pH adjuster 213, and sodium polyacrylate as a water-absorbing resin; Example 3: A mixture of sodium formate as the first humidity-conditioning component 211, sodium carbonate as the pH adjuster 213, and sodium polyacrylate as a water-absorbing resin; Example 4: A mixture of potassium formate as the first humidity-conditioning component 211, sodium carbonate as the pH adjuster 213, and sodium polyacrylate as a water-absorbing resin; and Example 5: A mixture of potassium acetate as the first humidity-conditioning component 211, sodium carbonate as the pH adjuster 213, and sodium polyacrylate as a water-absorbing resin.

[0086] In the samples of Examples 1 to 5, the weight ratio of the first humidity-conditioning component 211 to the pH adjuster 213 is 4:1. When the humidity-conditioning material 200 contains the first humidity-conditioning component 211 and the pH adjuster 213, the weight ratio of their total weight to the water-absorbent resin is 5:1.

[0087] As shown in Figure 10, the samples of Examples 1 to 3 deliquesce at a relative humidity of 50 to 60%, and rapidly absorb moisture in a high-humidity environment where the relative humidity is equal to or greater than the threshold value (hereinafter, this characteristic will be referred to as "threshold characteristic"). Therefore, when sodium propionate or sodium formate is selected as the first humidity-conditioning component 211, the humidity-conditioning material 200 absorbs a large amount of moisture in a high-humidity environment of 60% or greater relative humidity and can be regenerated to a dry state in a low-humidity environment of 50% or less relative humidity without artificial heating. Specifically, for sodium formate or sodium propionate, the difference between the moisture absorption rate in a 90% relative humidity environment and the moisture absorption rate in a 40% relative humidity environment is 200% or greater, allowing the humidity-conditioning component to absorb and release moisture at a rate more than twice its weight. Therefore, the humidity-regulating material 200 absorbs moisture during times such as nighttime or early morning when the temperature is low and the relative humidity is high, and is regenerated during the daytime when the temperature is high and the relative humidity is relatively low, thereby significantly increasing the amount of moisture absorbed and released during the day-night cycle and preventing condensation.

[0088] Furthermore, when comparing Example 1 and Example 2, by adding the second humidity-regulating component 212 in Example 2, the moisture absorption rate at relative humidity of 60% or more becomes higher, the amount of moisture absorbed and released during the day-night cycle becomes significantly larger, and the effect of preventing condensation becomes even higher.

[0089] As shown in Figure 10, the samples of Examples 4 and 5 do not have threshold characteristics, but deliquesce at relative humidity levels below 60%, and their moisture absorption rates increase rapidly as the relative humidity increases. Therefore, when potassium formate or potassium acetate is selected as the first humidity-conditioning component 211, the humidity-conditioning material 200 absorbs a large amount of moisture in a relatively high relative humidity environment and can be regenerated to a dry state in a relatively low relative humidity environment without artificial heating. Specifically, for potassium formate or potassium acetate, the difference between the moisture absorption rate in a 90% relative humidity environment and the moisture absorption rate in a 40% relative humidity environment is 200% or more, allowing the humidity-conditioning material 200 to absorb and release moisture at a rate more than twice its weight. Therefore, the humidity-conditioning material 200 absorbs moisture during times when the temperature is low and the relative humidity is high, for example, at night or early in the morning, and is regenerated during times when the temperature is high and the relative humidity is relatively low. This significantly increases the amount of moisture absorbed and released during the daytime cycle, preventing condensation.

[0090] As described above, the humidity-conditioning material 200 using sodium propionate, sodium formate, potassium formate, or potassium acetate and sodium carbonate has excellent humidity-conditioning properties because it can obtain a large humidity-conditioning capacity when the ambient humidity environment changes. The corrosiveness of sodium propionate, sodium formate, potassium formate, and potassium acetate will be described later.

[0091] Figure 11A shows moisture sorption isotherms for sodium propionate, sodium carbonate, and the sample of Example 1. Figure 11B shows moisture sorption isotherms for sodium formate, sodium carbonate, and the sample of Example 3. Figure 11C shows moisture sorption isotherms for potassium formate, sodium carbonate, and the sample of Example 4. Figure 11D shows moisture sorption isotherms for potassium acetate, potassium carbonate, and the sample of Example 5.

[0092] As shown in Figures 11A to 11C, adding 1 part by weight of sodium carbonate to 4 parts by weight of sodium propionate, sodium formate, or potassium formate does not significantly affect the moisture absorption isotherm. Furthermore, as shown in Figure 11D, adding 1 part by weight of potassium carbonate to 4 parts by weight of potassium acetate does not significantly affect the moisture absorption isotherm. Therefore, even when 1 part by weight of sodium carbonate is added to 4 parts by weight of sodium propionate, sodium formate, or potassium formate, the high humidity-regulating properties of sodium propionate, sodium formate, and potassium formate are maintained, respectively. Furthermore, even when 1 part by weight of potassium carbonate is added to 4 parts by weight of potassium acetate, the high humidity-regulating properties of potassium acetate are maintained.

[0093] Next, the results of the corrosion test on the sample in which the first humidity control component 211, the pH adjuster 213, and the water-absorbent resin were mixed will be described.

[0094] FIG. 12 is a diagram illustrating a corrosion test method.

[0095] As shown in FIG. 12 , in the corrosion test, a sealed container 302 was placed in a thermostatic chamber 301, and a sample 303 and two types of iron pieces 304 were placed in the sealed container 302. The sample 303 was placed on the inner bottom surface of the sealed container 302. The two types of iron pieces 304 were fixed to the underside of the lid of the sealed container 302. The two types of iron pieces 304 were iron pieces that were not coated with a corrosion-resistant film and had their base exposed, and iron pieces that were coated with a corrosion-resistant film but had cross-cuts in the film that exposed part of their base. The corrosion-resistant film was formed by tin plating. The temperature inside the thermostatic chamber 301 was maintained at 60°C, and the temperature inside the sealed container 302 was also maintained at 60°C. The sample 303 was wetted with water, and the equilibrium humidity of the sample 303 was adjusted to 90% RH. As a result, the humidity inside the sealed container 302 was maintained at 90% RH. After maintaining this state for three days, the two types of iron sides 304 were photographed to obtain images showing the results of the corrosion test.

[0096] 13A to 13D are images showing the results of the corrosion tests of the samples of Examples 6 to 9. FIGS. 13E and 13F are images showing the results of the corrosion tests of the samples of Comparative Examples 1 and 2, respectively.

[0097] The samples of Examples 6 to 9 are the following mixtures:

[0098] Example 6: A mixture of sodium propionate as the first humidity-regulating component 211, sodium carbonate as the pH adjuster 213, and sodium polyacrylate as a water-absorbing resin; Example 7: A mixture of sodium formate as the first humidity-regulating component 211, sodium carbonate as the pH adjuster 213, and sodium polyacrylate as a water-absorbing resin; Example 8: A mixture of potassium formate as the first humidity-regulating component 211, sodium carbonate as the pH adjuster 213, and sodium polyacrylate as a water-absorbing resin; and Example 9: A mixture of potassium acetate as the first humidity-regulating component 211, sodium carbonate as the pH adjuster 213, and sodium polyacrylate as a water-absorbing resin.

[0099] In the samples of Examples 6 to 9, the weight ratio of the first humidity control component 211, the pH adjuster 213, and the water-absorbent resin was 4:1:4.

[0100] The sample of Comparative Example 1 is Silica Gel B. The sample of Comparative Example 2 is a mixture of sodium formate and sodium polyacrylate.

[0101] The pH of the samples of Examples 6 to 9 and Comparative Examples 1 and 2 was all 7 or higher.

[0102] As shown in Figures 13A to 13E, the samples of Examples 6 to 9 and the sample of Comparative Example 1 did not corrode the two types of iron pieces. On the other hand, as shown in Figure 13F, the sample of Comparative Example 2 corroded the two types of iron pieces. Corrosion progressed from the exposed base material. From these results, it can be seen that the humidity conditioner 200 made of sodium propionate, sodium formate, potassium formate, or potassium acetate, sodium carbonate, and sodium polyacrylate, and the humidity conditioner made of silica gel B, have low corrosiveness. On the other hand, it can be seen that the humidity conditioner made of sodium formate and sodium polyacrylate, but not containing sodium carbonate, has high corrosiveness. Considering these facts and the fact that silica gel B can only absorb and release a small amount of moisture relative to the weight of the humidity-regulating component, it can be seen that humidity-regulating material 200 containing either sodium propionate, sodium formate, potassium formate, or potassium acetate as first humidity-regulating component 211, sodium carbonate as pH adjuster 213, and sodium polyacrylate as the water-absorbing resin has a high humidity-regulating function and only low corrosiveness.

[0103] It has been explained that the humidity conditioner according to the present disclosure preferably further comprises a pH adjuster 213, which will be described in more detail below.

[0104] The longer the alkyl group contained in the carboxylic acid, the greater the acid dissociation constant pKa of the carboxylic acid, and the lower the acidity of the carboxylic acid. Therefore, the longer the alkyl group contained in the carboxylic acid, the more easily the carboxylic acid is liberated from its salt under acidic conditions. When the first humidity-conditioning component 211 contains sodium propionate, sodium formate, potassium formate, or potassium acetate and the water-absorbing material is an ionic resin, protons are supplied from the water-absorbing material to acidify the humidity-conditioning material, liberating propionic acid, formic acid, or acetic acid, an acid with a concentration that causes odor, from the first humidity-conditioning component 211. Therefore, the humidity-conditioning material 200 preferably further includes a pH adjuster 213 to further reduce odor. Adjusting the hydrogen ion concentration pH of the humidity-conditioning material 200 to the alkaline side with the pH adjuster 213 suppresses acid liberation and improves odor. Therefore, the pH adjuster 213 is preferably one that can adjust the hydrogen ion concentration pH of the humidity-conditioning material 200 to the alkaline side. Furthermore, when the first humidity-conditioning component 211 contains sodium formate, potassium formate, or potassium acetate and the water-absorbing material is an ionic resin, protons are supplied from the water-absorbing material, causing the humidity-conditioning material to become acidic, and corrosive formic acid or acetic acid is liberated from the first humidity-conditioning component 211. Therefore, it is preferable that the humidity-conditioning material 200 further includes a pH adjuster 213 to suppress corrosiveness. By adjusting the hydrogen ion concentration pH of the humidity-conditioning material 200 to the alkaline side using the pH adjuster 213, acid liberation can be suppressed and corrosiveness can be suppressed. Therefore, it is preferable that the pH adjuster 213 be one that can adjust the hydrogen ion concentration pH of the humidity-conditioning material 200 to the alkaline side.

[0105] Table 4 shows the measurement results of odor and pH value for each combination of the type of first humidity-conditioning component 211, the type of water-absorbent resin, the type of pH adjuster 213, and the addition rate of pH adjuster 213. The addition rate of pH adjuster 213 indicates the ratio of the weight of pH adjuster 213 to the total weight.

[0106]

[0107] In Table 4, "improved" odor means that the odor has been improved to the extent that it is not detectable by humans.

[0108] As shown in Table 4, when the first humidity-conditioning component 211 was sodium propionate, odor was improved when the pH adjuster 213 was potassium carbonate, sodium carbonate, or dipotassium hydrogen phosphate. In particular, when the pH adjuster 213 was potassium carbonate or sodium carbonate, odor was significantly improved even when the addition rate of the pH adjuster 213 was small. For example, when the pH adjuster 213 was potassium carbonate, odor was significantly improved when the addition rate of the pH adjuster 213 was 4.0% or more, and when the pH adjuster 213 was sodium carbonate, odor was significantly improved when the addition rate of the pH adjuster 213 was 8.0% or more. Furthermore, when odor was significantly improved, the hydrogen ion concentration pH of the humidity-conditioning material 200 was shifted to the alkaline side.

[0109] On the other hand, when the first humidity-conditioning component 211 was sodium propionate and the pH adjuster 213 was calcium carbonate, the low solubility prevented the pH of the humidity-conditioning material 200 from being increased, and the odor was not improved. Note that when the first humidity-conditioning component 211 was sodium propionate and the pH adjuster 213 was dipotassium hydrogen phosphate, the odor was not improved unless the addition rate of the pH adjuster 213 was 30.0% or more.

[0110] Therefore, when the first humidity-conditioning component 211 is sodium propionate, it is preferable that the pH adjuster 213 contains at least a carbonate. Furthermore, it is more preferable that the pH adjuster 213 is a sodium salt that does not significantly affect the humidity-conditioning properties of the first humidity-conditioning component 211 or the second humidity-conditioning component 212. Note that a non-ionic substance may also be used as the pH adjuster 213.

[0111] As shown in Table 4, when the first humidity-conditioning component 211 was sodium formate or potassium formate, the odor was improved when the pH adjuster 213 was sodium carbonate. Also, when the first humidity-conditioning component 211 was potassium acetate, the odor was improved when the pH adjuster 213 was potassium carbonate or sodium carbonate.

[0112] As described above, the humidity-conditioning material 200 according to the present disclosure exhibits only low corrosiveness, is odorless, and exhibits a high humidity-conditioning function by absorbing or releasing moisture.

[0113] [Humidity Conditioning Member] Fig. 14 is a diagram schematically illustrating a humidity control member 100 according to the present disclosure, which is a diagram illustrating the humidity control member 100 in which a humidity control material 200 is dispersed in a nonwoven fabric. As shown in Fig. 14, the humidity control member 100 according to the present disclosure includes the humidity control material 200 described above and a support 20 that supports the humidity control material 200.

[0114] Furthermore, as shown in Fig. 14, the humidity control member 100 according to the present disclosure may have a support 20 made of nonwoven fabric, with the humidity control material 200 dispersed in the nonwoven fabric. Nonwoven fabric is preferable because of its high water vapor permeability. Therefore, the humidity control member 100 shown in Fig. 14 can have a high ratio of surface area to volume, which can increase the rate of moisture absorption or release. Note that the support 20 may be made of hydrophilic fibers such as porous materials and woven fabrics, in addition to nonwoven fabric.

[0115] The humidity conditioner 200 may be adhered to the surface of the support 20 with a binder or the like. On the other hand, if the water absorbing material can also serve as a binder, no binder is necessary.

[0116] FIG. 15 is a schematic diagram of a humidity control member 100 according to the present disclosure, showing the humidity control member 100 in which a humidity control material 200 is provided between nonwoven fabrics. The humidity control member 100 according to the present disclosure may be in the form of a sheet. As shown in FIG. 15 , the humidity control member 100 according to the present disclosure may have a support 20 made of nonwoven fabric, with the humidity control material 200 provided between the nonwoven fabrics. The humidity control material 200 may be bonded to the support 20 by a binder 30 dispersed therein. The sheet may be made flame-retardant by mixing flame-retardant fibers into the nonwoven fabric. Furthermore, the first humidity control component 211 and the second humidity control component 212 may be present within the water absorbent body 214, or may be mixed with each other without being present within the water absorbent body 214.

[0117] FIG. 16 is a schematic diagram of a humidity control member 100 according to the present disclosure, showing a humidity control member in which a humidity control material 200 is provided on the surface or inside of a breathable substrate. As shown in FIG. 16, the humidity control member 100 according to the present disclosure may have a support 20 as a breathable substrate, and the humidity control material 200 may be provided on the surface or inside of the breathable substrate. As the breathable substrate, a pleated structure, a honeycomb structure, or the like is preferred. In this way, the surface area in contact with air is increased, thereby improving the humidity control function.

[0118] As described above, according to the present disclosure, it is possible to provide the humidity conditioner 200 and humidity conditioner member 100 that have improved anti-corrosion properties and absorb or release moisture to provide a high humidity conditioning function.

[0119] Although each embodiment and each example of the present disclosure have been described in detail above, it will be readily apparent to those skilled in the art that many modifications are possible without substantially departing from the novel features and effects of the present disclosure. Therefore, all such modifications are intended to be included within the scope of the present disclosure.

[0120] For example, a term that is described at least once in the specification or drawings together with a different term having a broader or equivalent meaning can be replaced with that different term anywhere in the specification or drawings. Furthermore, the configurations and operations of the humidity conditioner and humidity conditioner member are not limited to those described in the embodiments and examples of the present disclosure, and various modifications are possible.

Claims

1. A moisture-conditioning material comprising: a first moisture-conditioning component that absorbs or releases moisture; and a water-absorbent body containing a water-absorbing material, wherein the first moisture-conditioning component is sodium propionate.

2. A humidity-conditioning material comprising: a first humidity-conditioning component that absorbs or releases moisture; and a water-absorbent body containing a water-absorbing material, wherein the first humidity-conditioning component contains at least one selected from the group consisting of sodium propionate, sodium formate, potassium formate, and potassium acetate.

3. The humidity conditioner according to claim 1 or 2, further comprising a pH adjuster.

4. The humidity conditioner according to claim 3, characterized in that the pH adjuster alone exhibits alkaline properties.

5. The humidity conditioner according to claim 3 or 4, characterized in that the pH adjuster contains at least a carbonate.

6. A humidity control material according to any one of claims 1 to 5, further comprising a second humidity control component that absorbs or releases moisture, the second humidity control component being a sodium salt having a deliquescence point at 60 to 90% RH.

7. The humidity conditioner according to claim 6, wherein the second humidity conditioner component is at least one selected from the group consisting of sodium acetate and sodium carbonate.

8. The humidity-regulating material according to claim 1 or 2, further comprising a second humidity-regulating component that absorbs or releases moisture and a pH adjuster, wherein the second humidity-regulating component is sodium acetate, and the pH adjuster is sodium carbonate.

9. The humidity conditioner according to any one of claims 1 to 8, characterized in that the water absorbent material contains at least one material selected from the group consisting of water absorbent resins and clay minerals.

10. The humidity conditioner according to claim 9, characterized in that the water-absorbent resin contains sodium polyacrylate.

11. A humidity control member comprising: a humidity control material according to any one of claims 1 to 10; and a support that supports the humidity control material.

12. The humidity control member according to claim 11, wherein the support is a nonwoven fabric, and the humidity control material is provided between the nonwoven fabric.

13. The humidity control member according to claim 11, wherein the support is a nonwoven fabric, and the humidity control material is dispersed in the nonwoven fabric.

14. The humidity-conditioning member according to claim 11, characterized in that the support is a breathable substrate, and the humidity-conditioning material is provided on the surface or inside of the breathable substrate.

Images