Humidity control composition, humidity control material, and humidity control member

Abstract

Provided is a composition that has film formability and has moisture-absorbing and moisture-desorbing properties.　The composition according to the present disclosure comprises a deliquescent salt (A) and a cellulose-based compound (B) having an LCST ranging from 40°C inclusive to 200°C exclusive. The composition has at least one of features [1] and [2]. Feature [1]: The cellulose-based compound (B) content is at least 45 wt% of the total content of the deliquescent salt (A) plus the cellulose-based compound (B). Feature [2]: Formula (1) and formula (2) are satisfied.

Description

Humidity-conditioning composition, humidity-conditioning material, and humidity-conditioning member

[0001] The present disclosure relates to a composition useful for humidity control applications, and a humidity control material and humidity control member containing the composition. This disclosure claims priority to Japanese Patent Application No. 2023-131552, filed in Japan on August 10, 2023, the contents of which are incorporated herein by reference.

[0002] BACKGROUND ART Techniques for capturing and storing moisture and releasing the stored moisture as needed are used in technical fields such as air conditioning, drying, and water supply.

[0003] Zeolite and silica gel are known to have excellent moisture absorption properties and are used as desiccants. However, the problem is that they only capture a small amount of moisture per unit mass. Another problem is that they require high temperatures of 200-300°C to release the captured moisture, which consumes a large amount of energy to release the moisture.

[0004] Other deliquescent salts such as calcium chloride, magnesium chloride, and aluminum chloride are known to have excellent hygroscopic properties, but these deliquescent salts tend to liquefy after absorbing moisture, causing problems with water leakage.

[0005] A known method for preventing water leakage is to use a gelling agent in combination. Patent Document 1 describes the use of a mixture obtained by mixing a deliquescent salt with a nonionic cellulose compound as a gelling agent as a desiccant. It also describes that water leakage can be prevented when 10 to 30% by weight of the nonionic cellulose compound is used. It also describes that when the amount of the nonionic cellulose compound used is excessive, exceeding 33.3% by weight, the content of the deliquescent salt becomes relatively small, resulting in a decrease in hygroscopicity.

[0006] JP 2010-194497 A

[0007] However, the desiccant described in Patent Document 1 contains a large amount of deliquescent salt to ensure sufficient moisture absorption, which makes it difficult to form a free-standing film due to its poor film-forming ability and shape stability. In addition, the desiccant is prone to cracking due to moisture absorption and release.

[0008] Therefore, an object of the present disclosure is to provide a composition that has film-forming properties and moisture absorbing and releasing properties. Another object of the present disclosure is to provide a composition that has moisture absorbing and releasing properties, film-forming properties, and shape stability. Another object of the present disclosure is to provide a composition that has excellent moisture absorbing and releasing properties and film-forming properties, and the property of releasing trapped moisture with little energy consumption. Another object of the present disclosure is to provide a composition that has excellent moisture absorbing and releasing properties, film-forming properties, and shape stability, and the property of releasing trapped moisture with little energy consumption. Another object of the present disclosure is to provide a humidity conditioner containing the composition, and a humidity conditioner member containing the composition.

[0009] The present inventors conducted extensive research to solve the above problems and found the following: 1. Although the following cellulose compound (B) itself exhibits almost no moisture absorption, when it is blended with the following deliquescent salt (A) in a specific ratio, it has the effect of improving moisture absorption compared to the case where the following deliquescent salt (A) is used alone. 2. A composition containing the following deliquescent salt (A) and the following cellulose compound (B) efficiently releases the absorbed moisture when heated at a temperature above the LCST of the cellulose compound (B) after absorbing moisture. 3. By setting the LCST of the cellulose compound (B) low, it is possible to reduce the energy consumption during moisture release. 4. A composition containing the following deliquescent salt (A) and the following cellulose compound (B) in a specific ratio has excellent film-forming properties, and a free-standing film can be formed by adding water to the composition, applying a thin layer, and drying it. 5. The free-standing film can stably maintain its shape without cracking even after repeated moisture absorption and release. The present disclosure has been completed based on these findings.

[0010] That is, the present disclosure provides a composition comprising a deliquescent salt (A) and a cellulose-based compound (B) having an LCST in the range of 40°C or higher and lower than 200°C, wherein the content of the cellulose-based compound (B) is 45% by weight or higher of the total content of the deliquescent salt (A) and the cellulose-based compound (B).

[0011] The present disclosure also provides a composition (C) comprising a deliquescent salt (A) and a cellulose-based compound (B) having an LCST in the range of 40°C or higher and lower than 200°C, wherein the composition satisfies the following formulas (1) and (2): (In formula (1), W(C) represents the weight of the composition (C), and W(CA) represents the weight of the deliquescent salt (A) contained in the composition (C). Ab1(C) represents the amount of water absorbed per unit amount when the composition (C) is subjected to a humidity exposure treatment of leaving it standing in an atmosphere of 25°C and 85% RH for 1 hour. Ab1(A) represents the amount of water absorbed per unit amount when the deliquescent salt (A) is subjected to a humidity exposure treatment of leaving it standing in an atmosphere of 25°C and 85% RH for 1 hour. In formula (2), W(C) is the same as above. W(Cw 24 ) indicates the weight of the composition (C) after it has been subjected to a humidity exposure treatment in which it is left standing in an atmosphere of 25°C and 85% RH for 24 hours, and W(Cw 24 ) 10 indicates the weight of the composition (C) after the wet exposure treatment, after drying at a temperature higher than the LCST for 10 minutes.

[0012] The present disclosure also provides the composition, wherein the deliquescent salt (A) is a metal chloride, bromide, iodide, sulfate, nitrate, or carbonate.

[0013] The present disclosure also provides the composition, wherein the cellulose compound (B) is a compound having a structural unit represented by the following formula (b): (In the formula, three Rs may be the same or different and represent a hydrogen atom, a hydrocarbon group, or a group in which two or more hydrocarbon groups are bonded via a linking group. However, of the three Rs, at least one is a hydrocarbon group or a group in which two or more hydrocarbon groups are bonded via a linking group. The hydrocarbon group may have a hydroxyl group.)

[0014] The present disclosure also provides a humidity conditioner comprising the composition.

[0015] The present disclosure also provides a humidity control member having a coating film containing the composition on a surface of a substrate.

[0016] The present disclosure also provides the humidity control member, which is a sheet-like humidity control member.

[0017] The present disclosure also provides a humidity control member including a porous substrate and the composition filled in the pores of the porous substrate.

[0018] The present disclosure also provides the humidity control member, which is a sheet-like humidity control member.

[0019] The composition of the present disclosure can capture moisture efficiently and without leakage, and can rapidly release almost all of the captured moisture when heated at a temperature above the LCST of the cellulose-based compound (B) contained in the composition. Furthermore, by setting the LCST of the cellulose-based compound (B) low, the energy required for moisture release can be reduced, and appropriate humidity can be maintained with less energy consumption. Furthermore, the composition has excellent film-forming properties and can form a self-supporting film (i.e., a film that can maintain its shape even without a support, etc.). Furthermore, even after repeated moisture absorption and release, the film can maintain its shape without cracking. For these reasons, the composition is useful as a humidity conditioner with low environmental impact, a humidity conditioner with excellent handleability, or as a raw material for the humidity conditioner.

[0020] FIG. 10 is a diagram showing the results of evaluating the moisture absorption and desorption properties of the sheet obtained in Example 4 and zeolite as a comparative example.

[0021] [Composition] The composition of the present disclosure (sometimes referred to herein as "composition (C)") contains a deliquescent salt (A) and a cellulose-based compound (B) having an LCST at a point within a range of 40°C or higher and lower than 200°C.

[0022] (Deliquescent Salt (A)) The deliquescent salt (A) is a salt that exhibits deliquescent properties due to moisture absorption. The salt may be an anhydrous salt or a salt containing water of crystallization.

[0023] The water vapor partial pressure of a saturated aqueous solution of the deliquescent salt (A) at 20° C. is, for example, 7 mmHg or less, preferably 6.5 mmHg or less, particularly preferably 5 mmHg or less, and most preferably 3 mmHg or less. The water vapor partial pressure is, for example, 0.1 mmHg or more, preferably 0.5 mmHg or more, and particularly preferably 1 mmHg or more.

[0024] The deliquescent salt (A) includes deliquescent inorganic salts and deliquescent organic salts.

[0025] Examples of deliquescent inorganic salts include metal salts.

[0026] Examples of the metal include alkali metals such as lithium, sodium, potassium, and cesium; alkaline earth metals such as calcium and magnesium; tin, aluminum, and zinc.

[0027] Examples of the metal salts include chlorides of the metals, bromides of the metals, iodides of the metals, carbonates of the metals, sulfates of the metals, and nitrates of the metals.

[0028] Examples of the metal chlorides include calcium chloride (water vapor partial pressure: 6.15 mmHg), magnesium chloride (water vapor partial pressure: 5.80 mmHg), lithium chloride (water vapor partial pressure: 1.96 mmHg), zinc chloride (water vapor partial pressure: 1.85 mmHg), aluminum chloride, and tin chloride.

[0029] Examples of the metal bromides include lithium bromide, sodium bromide, and potassium bromide.

[0030] Examples of the metal iodides include sodium iodide.

[0031] Examples of the metal carbonates include potassium carbonate.

[0032] As the deliquescent salt (A), deliquescent inorganic salts are preferred because of their high moisture absorption capacity, metal chlorides are particularly preferred, lithium chloride and / or calcium chloride are most preferred, and lithium chloride is particularly preferred.

[0033] (Cellulose-based Compound (B)) The cellulose-based compound has an LCST (Lower Critical Solution Temperature), and is a cellulose-based compound that exhibits reversible phase separation behavior, i.e., it is hydrophilic at temperatures below the LCST and becomes hydrophobic when heated to a temperature above the LCST. The cellulose-based compound dissolved in water at a temperature below the LCST easily forms a three-dimensional network structure due to intermolecular interactions, and gels by taking in moisture inside the structure.

[0034] The LCST of the cellulose-based compound is a temperature within a range of 40° C. or higher and lower than 200° C. From the viewpoint of improving moisture absorption, the lower limit of the LCST temperature range is preferably 45° C., particularly preferably 50° C., most preferably 55° C., and particularly preferably 60° C. From the viewpoint of reducing energy consumption during moisture release, the upper limit of the LCST temperature range is preferably 180° C., more preferably 150° C., more preferably 120° C., more preferably 100° C., even more preferably 95° C., particularly preferably 90° C., most preferably 85° C., and particularly preferably 80° C.

[0035] The LCST of the cellulose-based compound can be controlled by adjusting the substituents and the degree of polymerization of the cellulose-based compound.

[0036] Examples of the cellulose-based compound include compounds having a structural unit represented by the following formula (b). (In the formula, three Rs may be the same or different and represent a hydrogen atom or a hydrocarbon group which may have a hydroxyl group, provided that at least one of the three Rs is a hydrocarbon group which may have a hydroxyl group.)

[0037] The hydrocarbon group is preferably an aliphatic hydrocarbon group, and particularly preferably a saturated aliphatic hydrocarbon group (i.e., an alkyl group).

[0038] Examples of the alkyl group include linear or branched alkyl groups having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a s-butyl group, a t-butyl group, and a pentyl group. Of these, alkyl groups having 1 to 3 carbon atoms are preferred.

[0039] The compound having a structural unit represented by the formula (b) is a compound in which at least one of R in the formula (b) is a hydrocarbon group having a hydroxyl group (preferably an alkyl group having a hydroxyl group, particularly preferably a C 1-3 Compounds having a structural unit which is an alkyl group are preferred.

[0040] In addition, the compound having a constitutional unit represented by the formula (b) is a compound in which at least one of R in the formula (b) is a hydrocarbon group having a hydroxyl group (preferably an alkyl group having a hydroxyl group, particularly preferably a C 1-3 In addition to the structural unit in which at least one of R in formula (b) is a hydrocarbon group (preferably an alkyl group, particularly preferably C 1-3 Compounds having a structural unit which is an alkyl group are preferred.

[0041] That is, the compound having a structural unit represented by the formula (b) is preferably a compound having a structural unit in which at least one of R in formula (b) is a group represented by the following formula (r1), and is preferably a compound having a structural unit in which at least one of R in formula (b) is a group represented by the following formula (r1) and a compound having a structural unit in which at least one of R in formula (b) is a group represented by the following formula (r2). 1 -OH (r1) -R 2 (r2)

[0042] The cellulose-based compound has a plurality of structural units represented by formula (b), and the group represented by formula (r1) and the group represented by formula (r2) may be contained in the same structural unit or in different structural units.

[0043] In the formula, R 1represents an alkylene group, and is preferably an alkylene group having 1 to 3 carbon atoms, such as a methylene group, a methylmethylene group, a methylethylene group, an ethylene group, a dimethylmethylene group, a propylene group, or a trimethylene group. 2 represents an alkyl group, preferably an alkyl group having 1 to 3 carbon atoms. The bond extending from the left end of the formula is bonded to the oxygen atom at the 2-, 3-, or 6-position in formula (b).

[0044] In the total amount of compounds having a structural unit represented by formula (b), the content of the group represented by formula (r1) is, for example, 1 wt% or more. From the viewpoint of significantly improving the moisture absorption and desorption amount due to the synergistic effect with the deliquescent salt (A), the content of the group is preferably 3 wt% or more, more preferably 3.5 wt% or more, and particularly preferably 4 wt% or more. The upper limit of the content of the group is, for example, 20 wt%, preferably 15 wt%, more preferably 12 wt%, particularly preferably 10 wt%, and most preferably 8 wt%.

[0045] In the cellulose-based compound, a hydroxyalkoxy group such as a hydroxypropoxy group (—OR 1 a group represented by —OH; R 1 (wherein the same as above) is, for example, 0.01 to 0.50. The lower limit of the average number of moles of substitution is preferably 0.05, more preferably 0.07, particularly preferably 0.10, most preferably 0.12, and especially preferably 0.14. The upper limit of the average number of moles of substitution is preferably 0.40, particularly preferably 0.30, most preferably 0.20, and especially preferably 0.18.

[0046] In a compound having a structural unit represented by formula (b), the average molar substitution number (MS) of the group represented by formula (r1) per structural unit is, for example, 0.01 to 0.50. The lower limit of the average molar substitution number is preferably 0.05, more preferably 0.07, particularly preferably 0.10, most preferably 0.12, and especially preferably 0.14. The upper limit of the average molar substitution number is preferably 0.40, particularly preferably 0.30, most preferably 0.20, and especially preferably 0.18.

[0047] In the cellulose-based compound, an alkoxy group such as a methoxy group (—OR 2 A group represented by R 2 The average degree of substitution (DS) of the hydroxyl group (herein defined as above) is, for example, 0.5 to 2.5. The lower limit of the average degree of substitution is preferably 0.6, more preferably 0.8, more preferably 1.0, particularly preferably 1.2, most preferably 1.5, and particularly preferably 1.7. The upper limit of the average degree of substitution is preferably 2.2, particularly preferably 2.0, and most preferably 1.9.

[0048] In a compound having a structural unit represented by formula (b), the average degree of substitution (DS) of the group represented by formula (r2) per structural unit is, for example, 0.5 to 2.5. The lower limit of the average degree of substitution is preferably 0.6, more preferably 0.8, more preferably 1.0, particularly preferably 1.2, most preferably 1.5, and especially preferably 1.7. The upper limit of the average degree of substitution is preferably 2.2, particularly preferably 2.0, and most preferably 1.9.

[0049] The average molar substitution number (MS) of hydroxyalkoxy groups is the average number of moles of groups represented by the above formula (r1) added per glucose unit of the cellulose-based compound. The average degree of substitution (DS) of alkoxy groups is the average number of hydroxyl groups substituted with alkoxy groups per glucose unit of the cellulose-based compound. The average molar substitution number (MS) and the average degree of substitution (DS) can be determined by measuring based on the analytical method for hypromellose in the 18th edition of the Japanese Pharmacopoeia, and converting the obtained values.

[0050] The 2 wt % viscosity of the cellulose compound at 20°C is, for example, 5 to 10,000 mPa·s. From the viewpoint of improving film-forming properties, the lower limit of the viscosity is preferably 100 mPa·s, more preferably 150 mPa·s, particularly preferably 200 mPa·s, most preferably 300 mPa·s, and particularly preferably 350 mPa·s. From the viewpoint of excellent handleability, the upper limit of the viscosity is preferably 8,000 mPa·s, more preferably 6,000 mPa·s, more preferably 5,000 mPa·s, more preferably 3,000 mPa·s, even more preferably 2,000 mPa·s, even more preferably 1,500 mPa·s, particularly preferably 1,000 mPa·s, most preferably 800 mPa·s, and particularly preferably 500 mPa·s. The 2 wt % viscosity of a cellulose compound correlates with the molecular weight of the cellulose compound, and the 2 wt % viscosity can be adjusted by changing the molecular weight of the cellulose compound.

[0051] The cellulose-based compound may form a salt.

[0052] Examples of the salts include monovalent metal salts such as alkali metal salts (lithium salt, sodium salt, potassium salt, rubidium salt, cesium salt, etc.), divalent metal salts such as alkaline earth metal salts (calcium salt, magnesium salt, etc.), double salts of the above salts, quaternary ammonium salts, etc. Preferred salts are alkali metal salts such as sodium salts and quaternary ammonium salts.

[0053] For example, when the hydroxyl group of the cellulose compound forms a sodium salt, the hydroxyl group (—OH) becomes —ONa.

[0054] Specific examples of the cellulose-based compound include alkyl celluloses such as methyl cellulose and ethyl cellulose (preferably C 1-3 alkyl cellulose); hydroxyalkyl cellulose such as hydroxyethyl cellulose and hydroxypropyl cellulose (preferably hydroxy C 1-3alkyl cellulose); hydroxyalkyl alkyl cellulose such as hydroxyethyl methyl cellulose and hydroxypropyl methyl cellulose (preferably hydroxy C 1-3 Alkyl C 1-3 alkyl cellulose).

[0055] As the cellulose compound, the hydroxyalkyl cellulose or hydroxyalkyl alkyl cellulose is preferred, and the hydroxyalkyl alkyl cellulose is particularly preferred, in that the amount of moisture adsorbed and released is significantly improved due to a synergistic effect with the deliquescent salt (A).

[0056] (Composition (C)) The composition (C) contains a deliquescent salt (A) and a cellulose-based compound (B).

[0057] It is preferable that the content of the deliquescent salt (A) in the composition (C) (W(CA): weight) and the content of the cellulose compound (B) in the composition (C) (W(CB): weight) satisfy the following formula (3).

[0058] The formula shown on the left side of the formula (3) represents the ratio of the content of the cellulose compound (B) to the total content of the deliquescent salt (A) and the cellulose compound (B) contained in the composition (C), and this value is 45% or more. From the viewpoint of improving the moisture absorption amount per 1 g of the deliquescent salt (A) contained in the composition (C), this value is preferably 50% by weight or more.

[0059] The value of the mathematical expression shown on the left side of the formula (3) is preferably 98% by weight or less, more preferably 95% by weight or less, more preferably 90% by weight or less, even more preferably 85% by weight or less, still more preferably 80% by weight or less, particularly preferably 75% by weight or less, most preferably 70% by weight or less, and especially preferably 65% ​​by weight or less, in that the effect of exhibiting moisture absorption performance exceeding that when the deliquescent salt (A) is used alone can be obtained.

[0060] Furthermore, the content (W(CB)) of the cellulose compound (B) in the composition (C) is preferably 45 wt% or more (e.g., 45 to 98 wt%) of the total solid content contained in the composition (C). The upper limit of the content of the cellulose compound (B) is preferably 95 wt%, more preferably 90 wt%, even more preferably 85 wt%, even more preferably 80 wt%, particularly preferably 75 wt%, most preferably 70 wt%, and especially preferably 65 wt%, in order to obtain an effect of exhibiting moisture absorption performance exceeding that obtained when the deliquescent salt (A) is used alone. The lower limit of the content of the cellulose compound (B) is preferably 50 wt%, in order to improve the moisture absorption per unit amount of the deliquescent salt (A).

[0061] The content of the deliquescent salt (A) in the composition (C) (W(CA)) is preferably less than 55% by weight (for example, 1% by weight or more and less than 55% by weight) of the total content of the deliquescent salt (A) and the cellulose compound (B) contained in the composition (C). In order to obtain an effect of exhibiting moisture absorption performance exceeding that when the deliquescent salt (A) is used alone, the content of the deliquescent salt (A) is preferably 50% by weight or less, more preferably 45% by weight or less, particularly preferably 40% by weight or less, and most preferably 35% by weight or less. The lower limit of the content of the deliquescent salt (A) is preferably 5% by weight, more preferably 10% by weight, even more preferably 20% by weight, and particularly preferably 25% by weight.

[0062] The content of the deliquescent salt (A) in the composition (C) (W(CA)) is preferably less than 55% by weight (for example, 1% by weight or more and less than 55% by weight) of the total solid content contained in the composition (C). In order to obtain the effect of exhibiting moisture absorption performance exceeding that when the deliquescent salt (A) is used alone, the content of the deliquescent salt (A) is preferably 50% by weight or less, more preferably 45% by weight or less, particularly preferably 40% by weight or less, and most preferably 35% by weight or less. The lower limit of the content of the deliquescent salt (A) is preferably 5% by weight, more preferably 10% by weight, even more preferably 20% by weight, and particularly preferably 25% by weight.

[0063] In the total amount of composition (C), the combined content (W(CA) + W(CB)) of the deliquescent salt (A) and the cellulose compound (B) is, for example, 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more, even more preferably 80% by weight or more, particularly preferably 90% by weight or more, most preferably 95% by weight or more, and particularly preferably 99% by weight or more. The upper limit is 100% by weight. That is, composition (C) may contain only the deliquescent salt (A) and the cellulose compound (B).

[0064] The proportion of the total content of the deliquescent salt (A) and the cellulose compound (B) (W(CA) + W(CB)) in the total solid content contained in the composition (C) is, for example, 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more, even more preferably 80% by weight or more, particularly preferably 90% by weight or more, most preferably 95% by weight or more, and especially preferably 99% by weight or more. The upper limit is 100% by weight. In other words, the composition (C) may contain substantially only the deliquescent salt (A) and the cellulose compound (B) as solid contents.

[0065] In the present disclosure, the term "solid content" refers to components other than the solvent (including water and organic solvents), for example, components remaining after heating at 100°C for 5 hours under normal pressure. The composition (C) contains at least the deliquescent salt (A) and the cellulose-based compound (B) as solid contents.

[0066] The composition (C) may contain one or more other components in addition to the deliquescent salt (A) and the cellulose compound (B), such as a dispersant, an antioxidant, a surfactant, a leveling agent, an antifoaming agent, an antibacterial agent, and an antifungal agent.

[0067] The composition (C) can be produced, for example, by blending the deliquescent salt (A), the cellulose compound (B), and optionally other components, followed by stirring and mixing. For stirring and mixing, known or conventional devices (e.g., a planetary mixer, a single-screw or multi-screw extruder, a kneader, a dissolver, etc.) can be used. After stirring and mixing, the mixture can be dried as needed. The drying can be carried out by, for example, heat drying, drying under reduced pressure, freeze drying, solvent substitution, or the like.

[0068] The composition (C) exhibits excellent hygroscopicity at temperatures equal to or lower than the LCST and can capture a large amount of moisture. The cellulose-based compound (B) retains the captured moisture inside the three-dimensional network structure and gels, thereby preventing water leakage.

[0069] Furthermore, composition (C) contains a deliquescent salt (A) and a cellulose-based compound (B), and aggregation of the deliquescent salt (A) is suppressed by the presence of the cellulose-based compound (B). Therefore, in composition (C) containing the deliquescent salt (A) and the cellulose-based compound (B), the moisture absorption per unit amount of the deliquescent salt (A) is significantly improved compared to the case of the deliquescent salt (A) alone.

[0070] The composition (C) preferably satisfies the following formula (1).

[0071] In formula (1), W(C) represents the total weight (g) of the composition (C). More specifically, W(C) represents the dry weight of the composition (C), which is the weight of the composition (C) after drying by heating at 100°C under normal pressure (i.e., 1 atmosphere) for 30 minutes.

[0072] In formula (1), W(CA) represents the weight (g) of the deliquescent salt (A) contained in the composition (C). More specifically, W(CA) represents the weight of the deliquescent salt (A) contained in the composition (C) after drying by heating at 100°C for 30 minutes under normal pressure (i.e., 1 atmosphere).

[0073] In formula (1), Ab1(C) represents the amount of water absorbed per unit amount when the composition (C) is subjected to a humidity exposure treatment in which the composition is left standing in an atmosphere of 25°C and 85% RH for 1 hour.

[0074] Ab1(C) can be determined by heating and drying composition (C) at 100°C for 30 minutes under normal pressure (i.e., 1 atmosphere) and measuring the weight (W(C)), then subjecting the dried composition (C) to a humidity exposure treatment by leaving it to stand in an atmosphere of 25°C and 85% RH for 1 hour, measuring the weight (W(Cw1): g) after the humidity exposure treatment for 1 hour, and then inputting the determined weight into the following formula: Ab1(C) = [W(Cw1) - W(C)] / W(C).

[0075] Ab1(C) is, for example, 0.5 g / g or more, preferably 0.7 g / g or more, particularly preferably 1.0 g / g or more, and most preferably 1.5 g / g or more. The upper limit of Ab1(C) is, for example, 5.0 g / g.

[0076] In formula (1), Ab1(C) × [W(C) / W(CA)] (hereinafter sometimes referred to as "Ab1(CA)") indicates the amount of moisture absorption (g) per gram of deliquescent salt (A) contained in composition (C) when composition (C) is subjected to humid exposure in an atmosphere of 25°C and 85% RH for 1 hour, and is, for example, 3.5 g or more, preferably 4 g or more, particularly preferably 4.5 g or more. The upper limit of the amount of moisture absorption is, for example, 15 g, but may also be 10 g or 8 g.

[0077] In formula (1), Ab1 (A) represents the amount of water absorbed per unit amount when the deliquescent salt (A) is subjected to a humidity exposure treatment in which the salt is left standing alone in an atmosphere of 25°C and 85% RH for 1 hour.

[0078] Ab1(A) is a value determined in the same manner as Ab1(C), except that deliquescent salt (A) is used instead of composition (C). That is, deliquescent salt (A) is dried by heating alone at 100°C for 30 minutes under normal pressure (i.e., 1 atmosphere), and its weight (W(A)) is measured. Thereafter, the dried deliquescent salt (A) is subjected to a humidity exposure treatment in which it is left standing in an atmosphere of 25°C and 85% RH for 1 hour, and its weight (W(Aw1): g) after the humidity exposure treatment for 1 hour is measured, and the determined weight is then calculated by inputting the determined weight into the following formula: Ab1(A) = [W(Aw1) - W(A)] / W(A).

[0079] The value of the formula shown on the left side of the formula (1) is greater than 1.0 (for example, greater than 1.0 and not greater than 3.0, may be greater than 1.0 and not greater than 2.5, or may be greater than 1.0 and not greater than 2.0), preferably 1.10 or greater, particularly preferably 1.15 or greater, and most preferably 1.3 or greater.

[0080] Furthermore, the composition (C) preferably satisfies the following formula (1').

[0081] In formula (1'), W(C) and W(CA) are the same as above.

[0082] In formula (1'), Ab3(C) represents the amount of water absorbed per unit amount when the composition (C) is subjected to a humidity exposure treatment in which the composition is left standing in an atmosphere of 25°C and 85% RH for 3 hours.

[0083] In formula (1'), Ab3 (A) represents the amount of water absorbed per unit amount when the deliquescent salt (A) is subjected to a humidity exposure treatment in which the salt is left standing alone in an atmosphere of 25°C and 85% RH for 3 hours.

[0084] Ab3(C) and Ab3(A) can be calculated in the same manner as Ab1(C) and Ab1(A) in formula (1), except that the humid exposure time is changed from 1 hour to 3 hours.

[0085] Ab3(C) is, for example, 0.5 g / g or more, preferably 0.7 g / g or more, particularly preferably 1.0 g / g or more, most preferably 1.5 g / g or more, and particularly preferably 2.0 g / g or more. The upper limit of Ab3(C) is, for example, 5.0 g / g.

[0086] In formula (1'), Ab3(C) x [W(C) / W(CA)] (hereinafter sometimes referred to as "Ab3(CA)") indicates the amount of moisture absorption (g) per 1 g of the deliquescent salt (A) contained in the composition (C) when the composition (C) is subjected to humid exposure in an atmosphere of 25°C and 85% RH for 3 hours, and is, for example, 3.5 g or more, preferably 4 g or more, more preferably 4.5 g or more, even more preferably 5 g or more, and particularly preferably 5.5 g or more. The upper limit of the amount of moisture absorption is, for example, 15 g, but may also be 10 g or 8 g.

[0087] The value of the formula shown on the left side of the formula (1') is, for example, more than 1.0 and not more than 3.0, may be more than 1.0 and not more than 2.5, or may be more than 1.0 and not more than 2.0.

[0088] Furthermore, it is preferable that the composition (C) satisfies the following formula (1″).

[0089] In formula (1"), W(C) and W(CA) are the same as above.

[0090] In formula (1”), Ab 24 (C) indicates the amount of water absorbed per unit amount when the composition (C) is subjected to a humidity exposure treatment in which the composition is left standing in an atmosphere of 25° C. and 85% RH for 24 hours.

[0091] In formula (1”), Ab 24 (A) indicates the amount of water absorbed per unit amount when the deliquescent salt (A) is subjected to a humidity exposure treatment in which the salt is left alone in an atmosphere of 25° C. and 85% RH for 24 hours.

[0092] Ab 24 (C), Ab 24 (A) can be calculated in the same manner as Ab1(C) and Ab1(A) in formula (1), except that the humid exposure time is changed from 1 hour to 24 hours.

[0093] Ab 24 (C) is, for example, 0.5 g / g or more, preferably 1.0 g / g or more, particularly preferably 1.5 g / g or more, and most preferably 2.0 g / g or more. Ab 24 The upper limit of (C) is, for example, 5.0 g / g.

[0094] Ab in formula (1″) 24 (C)×[W(C) / W(CA)] (hereinafter “Ab 24 The moisture absorption amount (g) per 1 g of the deliquescent salt (A) contained in the composition (C) when the composition (C) is subjected to humid exposure in an atmosphere of 25°C and 85% RH for 24 hours is, for example, 4 g or more, preferably 4.5 g or more, more preferably 5 g or more, even more preferably 5.5 g or more, and particularly preferably 6 g or more. The upper limit of the moisture absorption amount is, for example, 15 g, but may also be 10 g or 8 g.

[0095] The value of the formula shown on the left side of the formula (1") is, for example, greater than 1.0 and equal to or less than 3.0, may be greater than 1.0 and equal to or less than 2.5, or may be greater than 1.0 and equal to or less than 2.0.

[0096] Furthermore, the cellulose compound (B) exhibits hydrophobicity at temperatures above the LCST and has the property of releasing moisture trapped inside the three-dimensional network structure, and therefore, when the composition (C) is heated at a temperature above the LCST, almost all of the trapped moisture (for example, 90% by weight or more, preferably 95% by weight or more) can be rapidly released.

[0097] The temperature above the LCST is, for example, preferably a temperature 10°C or more higher than the LCST, more preferably a temperature 15°C or more higher than the LCST, still more preferably a temperature 20°C or more higher than the LCST, and particularly preferably a temperature 25°C or more higher than the LCST.

[0098] Therefore, the temperature above the LCST is, for example, a temperature of LCST + 10°C or more, preferably a temperature of LCST + 15°C or more, particularly preferably a temperature of LCST + 20°C or more, and most preferably a temperature of LCST + 25°C or more. The upper limit of the temperature is, for example, a temperature of LCST + 100°C, preferably a temperature of LCST + 80°C, particularly preferably a temperature of LCST + 60°C, most preferably a temperature of LCST + 50°C, and particularly preferably a temperature of LCST + 40°C.

[0099] The composition (C) preferably has a moisture release amount of more than 70% after a drying time of 10 minutes, and preferably satisfies the following formula (2).

[0100] In the formula (2), W(C) represents the total weight (g) of the composition (C) (preferably the total weight (g) of the composition (C) in a dry state), as described above. 24 ) indicates the weight (g) of the composition (C) after 24 hours of humidity exposure treatment. The 24 hours of humidity exposure treatment is a treatment in which the composition (C) is left standing in an atmosphere of 25°C and 85% RH for 24 hours. W(Cw 24 ) 10 indicates the weight of composition (C) after 24 hours of wet exposure treatment and after drying at a temperature above the LCST for 10 minutes.

[0101] The value of the formula shown on the left side of the formula (2) is more than 70 (for example, more than 70 and not more than 100), preferably 75 or more, particularly preferably 80 or more, and most preferably 85 or more.

[0102] Furthermore, the composition (C) preferably has a moisture release rate of more than 80% after a drying time of 20 minutes, and preferably satisfies the following formula (2').

[0103] In formula (2'), W(C), W(Cw 24 ) is the same as above. W(Cw 24 ) 20 indicates the weight of composition (C) after 24 hours of wet exposure treatment and after drying at a temperature above the LCST for 20 minutes.

[0104] The value of the formula shown on the left side of the formula (2') is more than 80 (for example, more than 80 and 100 or less), preferably 85 or more, and particularly preferably 90 or more.

[0105] Furthermore, the composition (C) preferably has a moisture release rate of more than 90% after a drying time of 30 minutes, and preferably satisfies the following formula (2″).

[0106] In formula (2”), W(C), W(Cw 24 ) is the same as above. W(Cw 24 )30 indicates the weight of composition (C) after 24 hours of wet exposure treatment and after drying at a temperature above the LCST for 30 minutes.

[0107] The value of the formula shown on the left side of the formula (2'') is greater than 90 (for example, greater than 90 and 100 or less), and preferably 95 or greater.

[0108] The shape of the composition (C) is not particularly limited, and examples thereof include sheet, particle (including hollow particle, porous particle, and solid particle), powder, pellet, flake, irregular shape, fiber, and the like.

[0109] Furthermore, the composition (C) can be molded into a shape suitable for the intended use. The cellulose compound (B) contained in the composition is entangled with one another to form a three-dimensional network structure, and the shape can be stably maintained even after repeated moisture absorption and desorption.

[0110] The composition (C) has the above-mentioned properties and can therefore be suitably used as a material for forming a humidity conditioner (or a material for forming a humidity conditioner having a specific shape).

[0111] [Humidity Conditioner] The humidity conditioner of the present disclosure contains the composition (C). The humidity conditioner may contain other components as needed.

[0112] The proportion of composition (C) in the total amount of the humidity conditioner is, for example, 50% by weight or more. From the viewpoint of improving the amount of moisture absorption and desorption, the proportion of composition (C) is preferably 60% by weight or more, more preferably 70% by weight or more, even more preferably 80% by weight or more, particularly preferably 90% by weight or more, most preferably 95% by weight or more, and particularly preferably 99% by weight or more. The humidity conditioner may be composed essentially of composition (C) alone.

[0113] The shape of the humidity conditioner is not particularly limited, and examples thereof include sheet, particle (including hollow particle, porous particle, and solid particle), powder, pellet, flake, irregular shape, and fiber.

[0114] The sheet-shaped humidity conditioner can be produced, for example, by adding a solvent (e.g., water) to composition (C) and stirring and mixing to prepare a slurry, applying the obtained slurry to a desired thickness on a support or the like, drying the coating, and then peeling it off from the support or the like. The slurry can be applied by methods such as spin coating, stamping, dispensing, a squeegee method, spraying, brush coating, etc. Alternatively, the humidity conditioner can also be produced by a method in which a support or the like is immersed in the slurry to form a coating, the coating is dried, and then peeled off from the support or the like.

[0115] The amount of solvent (e.g., water) added is preferably in the range of, for example, 0.5 to 20% by weight (preferably 1 to 10% by weight) so that the solid content concentration in the slurry is in the range of, for example, 0.5 to 20% by weight (preferably 1 to 10% by weight), from the viewpoint of obtaining a sheet-shaped humidity conditioner with excellent coatability and uniform thickness.

[0116] The stirring / mixing and drying can be carried out in the same manner as the stirring / mixing and drying of the composition.

[0117] The particulate or pellet-shaped humidity conditioner can be produced by granulating the slurry and drying it.

[0118] The humidity-conditioning material contains the deliquescent salt (A) and the cellulose compound (B), and therefore is less likely to crack even when it is subjected to repeated moisture absorption and release, and can stably maintain its shape for a long period of time.

[0119] [Humidity Conditioning Member] The humidity conditioning member of the present disclosure according to embodiment 1 (hereinafter sometimes referred to as "humidity conditioning member 1") comprises a coating film containing composition (C) on the surface of a substrate. That is, the humidity conditioning member 1 has a laminated structure of a substrate and a film containing composition (C). The coating film may be laminated only on a portion of the substrate (on one side of the substrate in the case of a sheet-like substrate) or may be laminated on the entire surface of the substrate (on both sides of the substrate in the case of a sheet-like substrate).

[0120] The shape of the substrate is not particularly limited, and examples thereof include sheet-like, particulate (including hollow particulate, porous particulate, and solid particulate), rod-like (including columnar and needle-like), and fibrous shapes.

[0121] The substrate may have a single layer structure or a multi-layer structure including two or more layers of the same or different types.

[0122] Examples of the raw material for the substrate include plastic, paper, fiber, wood, rubber, foam, metal, and composites thereof.

[0123] Examples of the plastic include polyolefins (polyethylene, polypropylene, ethylene-propylene copolymer, etc.), polyesters (polyethylene terephthalate, etc.), vinyl chloride resins, vinyl acetate resins, polyimide resins, polyamide resins, fluorine-based resins, polycarbonates, etc.

[0124] Examples of the fiber material include cotton, hemp, pulp, rayon, cellulose acylate (for example, cellulose acetate), polyester, polyvinyl alcohol, polyamide, polyolefin, acrylic resin, and glass.

[0125] Examples of the rubber include natural rubber and synthetic rubber such as butyl rubber, styrene-butadiene rubber (SBR), butadiene rubber (BR), and isoprene rubber (IR).

[0126] The foamed material includes, for example, polyurethane foam, polychloroprene rubber foam, and the like.

[0127] The metals include, for example, aluminum and copper.

[0128] The substrate is preferably a sheet-like substrate, and particularly preferably a plastic film; a fabric such as a woven fabric, a nonwoven fabric, or a mesh fabric; a metal foil such as an aluminum foil; or paper.

[0129] The thickness of the sheet-like substrate is, for example, 0.09 mm or more (preferably 0.09 to 1.0 mm), and can be adjusted appropriately depending on the application.

[0130] The surface of the sheet-like substrate may be subjected to various surface treatments such as corona discharge treatment, plasma treatment, flame treatment, solvent treatment, and coating treatment.

[0131] The humidity control member 1 is preferably a sheet-like humidity control member.

[0132] The humidity control member 1 may include other components in addition to the substrate and the coating. When the humidity control member 1 is a sheet-shaped humidity control member, it may include other components such as a protective film and a filter.

[0133] The humidity-controlling member 1 can be produced, for example, by applying a slurry obtained by adding a solvent (e.g., water) to the composition (C) to the surface of the substrate by a method such as spin coating to form a coating film, and then drying the formed coating film.

[0134] The humidity-conditioning member 1 can also be produced by immersing the substrate in a slurry obtained by adding a solvent (e.g., water) to the composition (C), thereby adhering the composition (C) to the surface of the substrate, and then drying the substrate.

[0135] A humidity control member according to a second embodiment of the present disclosure (hereinafter, sometimes referred to as "humidity control member 2") includes a porous substrate and a composition (C) filled into the pores of the porous substrate. That is, the humidity control member 2 includes a porous substrate whose pores are filled with the composition (C).

[0136] The humidity control member 2 may further include a coating film containing a composition (C) on the surface of the porous substrate.

[0137] The shape of the porous substrate is not particularly limited, and examples thereof include sheet-like, particulate (including hollow particulate, porous particulate, and solid particulate), rod-like (including columnar and needle-like), fibrous, and the like.

[0138] Examples of raw materials for the porous substrate include the same as those for the substrate of the humidity control member 1 .

[0139] The porous substrate may have a single layer structure or a multi-layer structure including two or more layers of the same or different types.

[0140] The internal porosity of the porous substrate is, for example, 30% or more (preferably 30% or more and 90% or less). The porosity can be calculated from the following formula by cutting the porous substrate into a square with a side length L (cm), measuring the weight W (g) and the thickness D (cm): internal porosity (%) = 100 - 100 (W / ρ) / (L × L × D) (where ρ represents the density of the porous substrate).

[0141] The pore size of the porous substrate is, for example, 0.02 to 3 μm.

[0142] The porous substrate is preferably a sheet-like porous substrate, and particularly preferably a sheet-like porous substrate containing at least one material selected from woven fabric, nonwoven fabric, and mesh fabric.

[0143] The thickness of the sheet-like porous substrate is, for example, 0.1 mm or more (preferably 0.1 to 1 mm), and can be adjusted appropriately depending on the application.

[0144] The surface of the sheet-like porous substrate may be subjected to various surface treatments such as corona discharge treatment, plasma treatment, flame treatment, solvent treatment, and coating treatment.

[0145] The humidity control member 2 can be produced, for example, by immersing the porous substrate in a slurry obtained by adding a solvent (for example, water) to the composition (C), and then drying the slurry.

[0146] The filling rate of the internal voids of the porous substrate with the composition is, for example, 50% or more (preferably 60% or more). The internal voids of the porous substrate may be completely filled with the composition.

[0147] Because the humidity control members 1 and 2 contain composition (C), they can efficiently capture moisture in an atmosphere at a temperature equal to or lower than the LCST. Furthermore, by heating them at a temperature higher than the LCST, even at temperatures above the LCST, such as around 100°C, most of the captured moisture can be efficiently released. Therefore, by using the humidity control members, it is possible to maintain an appropriate humidity level with little energy consumption.

[0148] The humidity control members 1 and 2 can be used in, for example, air conditioners, ventilation systems, air purifiers, and the like.

[0149] The above-described configurations and combinations thereof of the present disclosure are merely examples, and additions, omissions, substitutions, and modifications of the configurations are possible as appropriate without departing from the spirit of the present disclosure. Furthermore, each aspect disclosed in this specification can be combined with any other feature disclosed in this specification. Furthermore, the present disclosure is not limited by the embodiments.

[0150] The present disclosure will be explained in more detail below using examples, but the present disclosure is not limited to these examples.

[0151] Example 1 5.6 g of hydroxypropyl methylcellulose (trade name "Metolose 65SH-400", manufactured by Shin-Etsu Chemical Co., Ltd.) as the cellulose compound (B) was added little by little to 95.2 g of distilled water at 70°C while stirring with a spatula to disperse. The mixture was then cooled in ice water at 5°C for 30 minutes. This gave an aqueous solution of hydroxypropyl methylcellulose. 0.2 g of lithium chloride (manufactured by Nacalai Tesque, Inc.) as the deliquescent salt (A) was added to the obtained aqueous solution of hydroxypropyl methylcellulose, and the mixture was stirred with a spatula. This gave slurry 1.

[0152] The obtained slurry 1 (12 g) was transferred to a TPX petri dish and dried for 2 hours in an oven at 100° C. Thus, a sheet 1 was obtained.

[0153] Examples 2 to 13 and Comparative Examples 1 to 11 Slurries and sheets were obtained in the same manner as in Example 1, except that the formulation was changed as shown in the table below. As a result, in Comparative Examples 5 to 7, gelation due to the cellulose compound (B) did not occur, and no sheets were obtained.

[0154] Example 14 A slurry was obtained in the same manner as in Example 4. The obtained slurry was applied to a substrate (PET, length × width × thickness = 5 cm × 5 cm × 188 μm, product name "Diafoil O-321E", manufactured by Mitsubishi Chemical Corporation) using a 10 mil applicator to form a coating film. Thereafter, the substrate on which the coating film was formed was dried at 100°C for 10 minutes to obtain a humidity-conditioning member in which a coating film (film thickness 213 μm) containing hydroxypropyl methylcellulose and lithium chloride was laminated on the substrate.

[0155] The slurries obtained in the Examples and Comparative Examples were evaluated for film-forming properties using the methods described below. The sheets obtained in the Examples and Comparative Examples were also evaluated for moisture absorption, moisture absorption synergy, moisture release, and sheet shape stability using the methods described below. The coating of the humidity control member obtained in Example 14 was also evaluated in the same manner as the sheet. The evaluation results are shown in the table below.

[0156] [Film-forming properties] The film-forming properties of the slurries obtained in the examples and comparative examples were evaluated according to the following criteria. <Evaluation criteria> Excellent: A sheet with no cracks and excellent self-standing film properties was obtained. Good: A sheet with cracks but having self-standing film properties was obtained. Poor: A sheet with self-standing film properties was not obtained.

[0157] [Moisture absorption] The sheets obtained in the examples and comparative examples were first subjected to a pre-drying treatment (drying temperature and time as shown in the table below) under normal pressure (1 atmosphere), and the dry weight (W(C): g) of the sheet was measured. Next, the sheet was placed in a constant temperature and humidity bath (temperature and humidity were set as shown in the table below) and exposed to a humid environment for 1 hour. The sheet weight (W(Cw1): g) after the humid exposure treatment was measured, and the moisture absorption amount (Ab1(C): g / g) of the sheet after 1 hour of humid exposure treatment was calculated using the following formula: Ab1(C) = [W(Cw1) - W(C)] / W(C).

[0158] Next, the moisture absorption amount (Ab1(CA): g / g) per unit amount of deliquescent salt (A) contained in the sheet after 1 hour of wet exposure treatment was calculated using the following formula: Ab1(CA) = Ab1(C) × [W(C) / W(CA)] (where W(C) is the dry weight of the sheet, and W(CA) is the content (g) of deliquescent salt (A) in the sheet after drying treatment).

[0159] In addition, the same procedure as above was carried out except that the time for exposing the sheet to a humid environment was changed from 1 hour to 3 hours or 24 hours, and the moisture absorption amount after 3 hours of humid exposure treatment (Ab3(CA): g / g) and the moisture absorption amount after 24 hours of humid exposure treatment (Ab 24 (CA: g / g) was calculated.

[0160] [Synergistic Effect of Moisture Absorption] The same deliquescent salt (A) as contained in the sheets obtained in the Examples and Comparative Examples was used alone, and in a state where it was spread out so as to have the same specific surface area as the deliquescent salt (A) contained in the sheet, it was subjected to treatment of exposing to the same humid environment as the sheet for 1 hour, 3 hours, or 24 hours, and the moisture absorption amount per unit amount of the deliquescent salt (A) alone after humid exposure treatment for 1 hour (Ab1(A): g / g), after humid exposure treatment for 3 hours (Ab3(A): g / g), and after humid exposure treatment for 24 hours (Ab 24 (A): g / g) was calculated.

[0161] The ratio of the moisture absorption amount of the sheet, which is the moisture absorption amount per unit amount of the deliquescent salt (A) contained in the sheet, to the moisture absorption amount of the deliquescent salt (A) alone, which is the moisture absorption amount per unit amount of the deliquescent salt (A), was calculated to confirm whether or not there was a synergistic effect on moisture absorption by mixing the deliquescent salt (A) with the cellulose compound (B).

[0162] [Moisture release] The sheets obtained in the examples and comparative examples were first subjected to a pre-drying treatment (drying temperature and time as shown in the table below) under normal pressure (1 atmosphere) to obtain a dry sheet, and the weight (W(C): g) of the obtained dry sheet was measured. Next, the dry sheet was placed in a constant temperature and humidity chamber set at a temperature of 25°C and a humidity of 85% RH, and the sheet was exposed to a humid environment for 24 hours to obtain a wet sheet, and the weight (W(C): g) of the obtained wet sheet was measured. 24 Next, the wet sheet was subjected to a drying treatment by placing it in an oven at 100°C for 10 minutes, and the weight after drying (W(Cw 24 ) 10 : g) was measured, and the moisture release amount per unit amount of the sheet during 10 minutes of drying treatment (Re 10 (C: g / g) and the moisture release rate (%) were calculated. 10 (C):g / g)=(W(Cw 24 ) -W(Cw 24 ) 10 ) / W(C) Moisture release rate (%) = [(W(Cw 24 ) -W(Cw 24 ) 10 ) / (W (Cw 24 )-W(C))]×100

[0163] In addition, the same procedure as above was carried out except that the drying treatment time was changed from 10 minutes to 20 minutes or 30 minutes, and the moisture release amount per unit amount of the sheet after 20 minutes of drying treatment (Re 20 (C): g / g) and the moisture release rate, and the moisture release amount per unit amount of sheet after 30 minutes of drying treatment (Re 30 (C: g / g) and the moisture release rate were calculated.

[0164] [Sheet shape stability] The shape stability of the sheets obtained in the examples and comparative examples was evaluated according to the following criteria. The moisture absorption and desorption test below was a test in which the wet exposure treatment was carried out for 24 hours, followed by the drying treatment for 30 minutes. <Evaluation criteria> Excellent: The sheet did not crack even after the moisture absorption and desorption test, and the sheet shape was stably maintained. Good: The sheet cracked after the moisture absorption and desorption test, but the sheet shape was maintained. Poor: The sheet underwent significant thermal shrinkage due to the moisture absorption and desorption test, and the sheet shape could not be maintained.

[0165]

[0166]

[0167]

[0168]

[0169] The abbreviations in the table are explained below. <Cellulose-based compounds (B)> HPMC400: hydroxypropyl methylcellulose, LCST 75°C, 2 wt% viscosity 350 to 550 mPa·s, degree of methoxy group substitution: 1.8, number of moles of hydroxypropoxy group substitution: 0.15, trade name "Metolose 65SH-400", manufactured by Shin-Etsu Chemical Co., Ltd. MC: methylcellulose, LCST 55°C, degree of methoxy group substitution: 1.8, trade name "Metolose SM400", manufactured by Shin-Etsu Chemical Co., Ltd. HPMC50: hydroxypropyl methylcellulose, LCST 75°C, 2 wt% viscosity 40 to 60 mPa·s, degree of methoxy group substitution: 1.8, number of moles of hydroxypropoxy group substitution: 0.15, trade name "Metolose 65SH50", manufactured by Shin-Etsu Chemical Co., Ltd. HPMC15: hydroxypropyl methylcellulose, LCST 75°C, 2 wt% viscosity 13 to 18 mPa·s, degree of methoxy group substitution: 1.9, molar number of hydroxypropoxy group substitution: 0.25, trade name "Metolose 60SH15", manufactured by Shin-Etsu Chemical Co., Ltd. HPMC10000: hydroxypropyl methylcellulose, 2 wt% viscosity 8000 to 12000 mPa·s, degree of methoxy group substitution: 1.9, molar number of hydroxypropoxy group substitution: 0.25, trade name "Metolose 60SH-10000", manufactured by Shin-Etsu Chemical Co., Ltd. CA: cellulose acetate, no LCST SAP: potassium poly(acrylate), no LCST, manufactured by Sigma-Aldrich <Other additives> PEG: polyethylene glycol, no LCST, weight average molecular weight 900 to 1100, trade name "Polyethylene Glycol 1000", manufactured by Tokyo Chemical Industry Co., Ltd.

[0170] [Evaluation of Moisture Absorption and Release Properties] The sheet obtained in Example 4 and the zeolite used as a comparative example were pre-dried by heating at 100°C for 60 minutes under normal pressure. Next, the dried sheet and zeolite were placed in a constant temperature and humidity chamber set at 15°C and 85% RH for 24 hours of humid exposure, and then placed in an oven at 100°C for drying. During the humid exposure and drying processes, the moisture content per unit amount (g / g) was measured sequentially. The results are shown in Figure 1.

[0171] From Tables 1 to 4 above and Figure 1, it can be seen that the composition of the present disclosure has excellent moisture absorption and release properties, has a large moisture absorption amount, and can efficiently release moisture captured by moisture absorption by heating at 100°C. On the other hand, it can be seen that zeolite has a significantly lower moisture absorption amount than the composition of the present disclosure, and furthermore, when heated at 100°C, it is hardly able to release moisture captured by moisture absorption. It can also be seen that the composition of the present disclosure has excellent film-forming properties, and that use of the composition can form a free-standing film with excellent moisture absorption and release properties. From the above, it can be seen that use of the composition of the present disclosure can form a humidity conditioner that is easy to handle, and can achieve maintenance of appropriate humidity with little energy consumption.

[0172] In summary, the configuration of the present disclosure and its variations are described below. [1] A composition comprising a deliquescent salt (A) and a cellulose-based compound (B) having an LCST in the range of 40°C or higher but lower than 200°C, wherein the content of the cellulose-based compound (B) is 45% by weight or more of the total content of the deliquescent salt (A) and the cellulose-based compound (B). [2] A composition (C) comprising a deliquescent salt (A) and a cellulose-based compound (B) having an LCST in the range of 40°C or higher but lower than 200°C, wherein the composition satisfies formulas (1) and (2). [3] The composition according to [1] or [2], wherein the deliquescent salt (A) is a metal chloride, bromide, iodide, sulfate, nitrate, or carbonate. [4] The composition according to [1] or [2], wherein the deliquescent salt (A) is at least one compound selected from calcium chloride, magnesium chloride, lithium chloride, zinc chloride, aluminum chloride, and tin chloride. [5] The composition according to [1] or [2], wherein the deliquescent salt (A) is lithium chloride and / or calcium chloride. [6] The composition according to any one of [1] to [5], wherein the cellulose compound (B) is a compound having a constitutional unit represented by the following formula (b): (wherein the three R's are the same or different and represent a hydrogen atom, a hydrocarbon group, or a group in which two or more hydrocarbon groups are bonded via a linking group, provided that at least one of the three R's is a hydrocarbon group or a group in which two or more hydrocarbon groups are bonded via a linking group. The hydrocarbon group may have a hydroxyl group.) [7] The composition according to [6], wherein the cellulose compound (B) is a compound having a structural unit represented by formula (b), and at least one of the three R's is a hydrocarbon group (preferably an alkyl group, particularly preferably an alkyl group having 1 to 3 carbon atoms) having a hydroxyl group. [8] The composition according to [7], wherein the average molar substitution number of the hydrocarbon group (preferably an alkyl group, particularly preferably an alkyl group having 1 to 3 carbon atoms) having a hydroxyl group is 0.01 to 0.50. [9] The composition according to any one of [6] to [8], wherein the cellulose compound (B) is a compound having a structural unit represented by formula (b), and at least one of the three R's is an alkoxy group (preferably an alkoxy group having 1 to 3 carbon atoms).

[10] The composition according to [9], wherein the average degree of substitution of the alkoxy groups (preferably alkoxy groups having 1 to 3 carbon atoms) is 0.5 to 2.5.

[11] The composition according to any one of [1] to [5], wherein the 2 wt % viscosity of the cellulose compound (B) at 20°C is 5 to 10,000 mPa·s.

[12] The composition according to any one of [1] to [5], wherein the cellulose compound (B) is a hydroxyalkyl cellulose and / or a hydroxyalkyl alkyl cellulose.

[13] The composition according to any one of [1] to [5], wherein the cellulose compound (B) is a hydroxyalkyl cellulose and / or a hydroxyalkyl alkyl cellulose. 1-3 Alkyl C 1-3

[14] The composition according to any one of [1] to

[13] , wherein the content of the deliquescent salt (A) and the content of the cellulose compound (B) satisfy the following formula (3): (Wherein W(CA) represents the content of the deliquescent salt (A), and W(CB) represents the content of the cellulose-based compound (B).)

[15] The composition according to any one of [1] to

[14] , wherein the content of the deliquescent salt (A) is less than 55 wt% of the total solid content contained in the composition (C).

[16] The composition according to any one of [1] to

[15] , wherein the content of the cellulose-based compound (B) is 45 wt% or more of the total solid content contained in the composition (C).

[17] The composition according to any one of [1] to

[16] , wherein the proportion of the total content of the deliquescent salt (A) and the cellulose-based compound (B) in the total amount of the composition (C) is 50 wt% or more.

[18] A humidity conditioner comprising the composition according to any one of [1] to

[17] .

[19] The humidity conditioner according to

[18] , wherein the proportion of composition (C) in the total amount of the humidity conditioner is 50% by weight or more.

[20] A humidity conditioner having a coating film comprising the composition according to any one of [1] to

[17] on the surface of a substrate.

[21] The humidity conditioner according to

[20] , which is a sheet-like humidity conditioner.

[22] A humidity conditioner comprising a porous substrate and the composition according to any one of [1] to

[17] filled into the pores of the porous substrate.

[23] The humidity conditioner according to

[22] , which is a sheet-like humidity conditioner.

[0173] The composition of the present disclosure can efficiently capture moisture without leakage, and can rapidly release almost all of the captured moisture when heated at a temperature above the LCST of the cellulose compound (B) contained in the composition. Therefore, the composition is useful as a humidity conditioner with low environmental impact or excellent handleability, or as a raw material therefor.

Claims

1. A composition comprising a deliquescent salt (A) and a cellulose compound (B) having an LCST in the range of 40°C or higher and lower than 200°C, wherein the content of the cellulose compound (B) is 45% by weight or more of the total content of the deliquescent salt (A) and the cellulose compound (B).

2. A composition (C) comprising a deliquescent salt (A) and a cellulose compound (B) having an LCST in the range of 40°C or higher and lower than 200°C, the composition satisfying the following formulas (1) and (2): (In formula (1), W(C) represents the weight of the composition (C), and W(CA) represents the weight of the deliquescent salt (A) contained in the composition (C). Ab1(C) represents the amount of water absorbed per unit amount when the composition (C) is subjected to a moist exposure treatment in which the composition is left standing for 1 hour in an atmosphere of 25°C and 85% RH. Ab1(A) represents the amount of water absorbed per unit amount when the deliquescent salt (A) is subjected to a moist exposure treatment in which the composition is left standing for 1 hour in an atmosphere of 25°C and 85% RH. In formula (2), W(C) is the same as above. W(Cw 24 ) indicates the weight of the composition (C) after it is subjected to a humid exposure treatment in which the composition (C) is left standing in an atmosphere of 25° C. and 85% RH for 24 hours, and W(Cw 24 ) 10 indicates the weight of the composition (C) after the wet exposure treatment, after drying at a temperature higher than the LCST for 10 minutes.

3. The composition according to claim 1 or 2, wherein the deliquescent salt (A) is a metal chloride, bromide, iodide, sulfate, nitrate, or carbonate.

4. The composition according to claim 1 or 2, wherein the cellulose compound (B) is a compound having a structural unit represented by the following formula (b): (In the formula, the three R's may be the same or different and each represent a hydrogen atom, a hydrocarbon group, or a group in which two or more hydrocarbon groups are bonded via a linking group. However, of the three R's, at least one is a hydrocarbon group or a group in which two or more hydrocarbon groups are bonded via a linking group. The hydrocarbon group may have a hydroxyl group.) 5. A humidity conditioner comprising the composition according to claim 1 or 2.

6. A humidity control member having a coating film containing the composition according to claim 1 or 2 on the surface of a substrate.

7. The humidity control member according to claim 6, which is a sheet-like humidity control member.

8. A humidity control member comprising a porous substrate and the composition according to claim 1 or 2 filled in the pores of the porous substrate.

9. The humidity control member according to claim 8, which is a sheet-like humidity control member.

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