Humidity control devices and humidity control systems

Abstract

To provide a humidity control device that can efficiently adsorb moisture from the air regardless of the humidity level in the air. [Solution] The humidity control device 10 comprises a base material 110 and an adsorption part 120 provided on the surface of the base material 110 and containing an adsorbent capable of adsorbing and desorbing moisture. The adsorbent has a moisture adsorption isotherm that determines the amount of moisture adsorbed when the relative humidity is 20% or higher. 20 The amount is 15% by mass or more, and the difference between the amount of water adsorbed at a relative humidity of 8% (Ad8) and the amount of water adsorbed at a relative humidity of 1% (Ad1) (Ad8-Ad1) is 5% by mass or more.

Description

[Technical Field]

[0001] This invention relates to a humidity control device and a humidity control system. [Background technology]

[0002] There is a growing demand for improved cabin environments in various vehicles, including automobiles. Specific requirements include reducing CO2 in the cabin to suppress driver drowsiness, humidifying the cabin, and removing harmful volatile components such as odor and allergy-inducing substances. While ventilation is an effective measure to meet these demands, it significantly reduces heater energy in winter, leading to decreased energy efficiency. This is particularly problematic for electric vehicles (BEVs), as this energy loss drastically reduces their driving range.

[0003] As a method to solve the above problems, Patent Document 1 proposes a heater element (humidity control device) comprising a honeycomb structure having an outer wall and partition walls disposed inside the outer wall that partition a plurality of cells forming a flow path extending from one end face to the other, and at least the partition walls being made of a material having PTC (Positive Temperature Coefficient) properties, and a pair of electrodes provided at predetermined positions on the honeycomb structure, and having an adsorption layer (functional material-containing layer) on the surface of the partition walls that adsorbs water vapor (moisture), etc. However, when this humidity control device is placed in an air conditioning duct, there is a problem that, with respect to the direction of airflow, water vapor, etc. can be efficiently adsorbed on the upstream side, but the adsorption efficiency of water vapor, etc. decreases on the downstream side because the humidity in the air decreases.

[0004] Furthermore, Patent Document 2 proposes a vehicle dehumidifier equipped with a moisture absorption device (humidity control device) that adsorbs water vapor (moisture) contained in the air inside the vehicle. The moisture absorption device comprises a plurality of moisture absorption sections with different moisture absorption characteristics and regeneration temperatures. The moisture absorption device has an upstream moisture absorption section, which is one of the moisture absorption sections located on the upstream side in the direction of airflow, and a downstream moisture absorption section, which is the other of the moisture absorption sections located on the downstream side in the direction of airflow. The upstream moisture absorption section has moisture absorption characteristics that allow it to adsorb more water vapor than the downstream moisture absorption section in high humidity environments, and the downstream moisture absorption section has adsorption characteristics that allow it to adsorb more water vapor than the upstream moisture absorption section in low humidity environments. This vehicle dehumidifier can efficiently adsorb water vapor from the air across the entire area of ​​the moisture absorption device in high humidity environments, and in low humidity environments, the moisture absorption function of the downstream moisture absorption section can sufficiently reduce the absolute humidity of the air inside the vehicle. However, the dehumidifying device used in this vehicle requires an upstream and downstream dehumidifying section, each carrying a different desiccant with varying desiccant properties. This results in a larger number of parts and a larger size for the dehumidifying device, as well as a more complex manufacturing process. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2023 / 074202 [Patent Document 2] Japanese Patent Publication No. 2022-80758 [Overview of the project] [Problems that the invention aims to solve]

[0006] As described above, the humidity control device described in Patent Document 1 has the problem that the humidity of the air decreases downstream, resulting in a decrease in the moisture adsorption efficiency. Furthermore, the humidity control device described in Patent Document 2 has the problem that, because it is necessary to provide multiple adsorption parts with different moisture absorption performance, the number and size of the moisture absorption device increases, as does the complexity of its manufacturing process.

[0007] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a humidity conditioning device and a humidity conditioning system that can efficiently adsorb moisture in air regardless of the humidity in the air. [Means for Solving the Problems]

[0008] As a result of intensive research conducted by the present inventors on humidity conditioning devices, it has been found that forming an adsorbing portion using an adsorbent satisfying that the moisture adsorption amount at a relative humidity of 20% or higher and the difference between the moisture adsorption amount at a relative humidity of 8% and the moisture adsorption amount at a relative humidity of 1% fall within predetermined ranges on a water adsorption isotherm enables efficient adsorption of moisture in air regardless of the humidity in air, and the present invention has been completed based on this finding. That is, the present invention is exemplified as follows.

[0009] <1> a base member, and an adsorbing portion that is provided on a surface of the base member and contains an adsorbent capable of adsorbing and desorbing moisture, comprising: wherein the adsorbent has a moisture adsorption amount Ad at a relative humidity of 20% or higher on a water adsorption isotherm 20 of 15% by mass or more, and a difference Ad8-Ad1 between a moisture adsorption amount Ad8 at a relative humidity of 8% and a moisture adsorption amount Ad1 at a relative humidity of 1% is 5% by mass or more.

[0010] <2> The humidity conditioning device according to <1>, wherein the adsorbent has a moisture adsorption amount Ad at a relative humidity of 20% or higher on a water adsorption isotherm 20 of 20% by mass or more.

[0011] <3> The humidity conditioning device according to <1>, wherein the adsorbent has a moisture adsorption amount Ad at a relative humidity of 20% or higher on a water adsorption isotherm 20 of 23% by mass or more.

[0012] <4> The humidity conditioning device according to <1>, wherein the adsorbent has a moisture adsorption amount Ad at a relative humidity of 20% or higher on a water adsorption isotherm 20 of 25% by mass or more.

[0013] <5> The adsorbent is such that, in a moisture adsorption isotherm, the difference between the amount of moisture adsorbed at 8% relative humidity (Ad8) and the amount of moisture adsorbed at 1% relative humidity (Ad1) (Ad8-Ad1) is 8% by mass or more. <1> ~ <4> A humidity control device described in any one of the following.

[0014] <6> The adsorbent is such that, in a moisture adsorption isotherm, the difference between the amount of moisture adsorbed at 8% relative humidity (Ad8) and the amount of moisture adsorbed at 1% relative humidity (Ad1) (Ad8-Ad1) is 10% by mass or more. <1> ~ <4> A humidity control device described in any one of the following.

[0015] <7> The adsorbent is such that, in a moisture adsorption isotherm, the difference between the amount of moisture adsorbed at 8% relative humidity (Ad8) and the amount of moisture adsorbed at 1% relative humidity (Ad1) (Ad8-Ad1) is 17% by mass or more. <1> ~ <4> A humidity control device described in any one of the following.

[0016] <8> The adsorbent is such that, in a moisture adsorption isotherm, the difference between the amount of moisture adsorbed at a relative humidity of 5% (Ad5) and the amount of moisture adsorbed at a relative humidity of 1% (Ad1) (Ad5-Ad1) is 5% by mass or more. <1> ~ <7> A humidity control device described in any one of the following.

[0017] <9> The adsorbent is such that, in a moisture adsorption isotherm, the difference between the amount of moisture adsorbed at 5% relative humidity (Ad5) and the amount of moisture adsorbed at 3% relative humidity (Ad3) (Ad5-Ad3) is 2% by mass or more. <1> ~ <8> A humidity control device described in any one of the following.

[0018] <10> The adsorbent is one or more selected from X-type zeolite, Y-type zeolite, A-type zeolite, and MFI-type zeolite. <1> ~ <9> A humidity control device described in any one of the following.

[0019] <11> The adsorbent is a Y-type zeolite with a molar ratio of SiO2 / Al2O3 of 10 or less. <1> ~ <9> A humidity control device described in any one of the following.

[0020] <12> The base material is a honeycomb structure having an outer peripheral wall and partition walls disposed inside the outer peripheral wall that divide and form a plurality of cells that serve as air passages extending from a first end face to a second end face. The adsorption portion is an adsorption layer provided on the surface of the partition wall. <1> ~ <11> A humidity control device described in any one of the following.

[0021] <13> The honeycomb structure further comprises a pair of electrodes provided on the first and second end faces of the honeycomb structure, or on the outer peripheral wall parallel to the direction in which the cells of the honeycomb structure extend. <12> The humidity control device described above.

[0022] <14> The honeycomb structure is composed of a material in which at least the partition walls have PTC properties. <12> or <13> The humidity control device described above.

[0023] <15> A flow path through which air can circulate, Arranged within the aforementioned flow path, <1> ~ <14> A humidity control device as described in any one of the items and A humidity control system equipped with this feature. [Effects of the Invention]

[0024] According to the present invention, it is possible to provide a humidity control device and a humidity control system that can efficiently adsorb moisture from the air regardless of the humidity level in the air. [Brief explanation of the drawing]

[0025] [Figure 1] This is a schematic cross-sectional view of a humidity control device according to an embodiment of the present invention. [Figure 2A] This is the moisture adsorption isotherm of an adsorbent usable in the present invention. [Figure 2B] This is the moisture adsorption isotherm of an adsorbent that cannot be used in the present invention. [Figure 3A] This is a schematic diagram of a cross-section parallel to the flow path direction of a humidity control device according to an embodiment of the present invention, in which a honeycomb structure is used in the base material. [Figure 3B]Figure 3A is a schematic diagram of the cross-section of the humidity control device along the line a-a'. [Figure 4] This is a schematic diagram of the overall configuration of a humidity control system according to an embodiment of the present invention. [Modes for carrying out the invention]

[0026] The humidity control device of the present invention comprises a base material and an adsorption part provided on the surface of the base material and containing an adsorbent capable of adsorbing and desorbing moisture. The adsorbent has a moisture adsorption isotherm that determines the amount of moisture adsorbed when the relative humidity is 20% or higher. 20 The amount of moisture adsorbed is 15% by mass or more, and the difference between the amount of moisture adsorbed at a relative humidity of 8% (Ad8) and the amount of moisture adsorbed at a relative humidity of 1% (Ad1) (Ad8-Ad1) is 5% by mass or more. By having such a configuration, the humidity control device of the present invention can efficiently adsorb moisture from the air regardless of the humidity of the air.

[0027] Furthermore, the humidity control system of the present invention comprises a flow path through which air can circulate and the above-mentioned humidity control device arranged within the flow path. Because the humidity control system of the present invention is equipped with the above-mentioned humidity control device, it can efficiently adsorb moisture from the air regardless of the humidity of the air.

[0028] The embodiments of the present invention will be described in detail below with reference to the drawings. The present invention is not limited to the following embodiments, and it should be understood that modifications, improvements, etc., to the following embodiments, based on the ordinary knowledge of those skilled in the art, without departing from the spirit of the invention, also fall within the scope of the present invention.

[0029] In this specification, a numerical range indicated by "~" means a range that includes the numbers before and after "~" as the lower and upper limits, unless otherwise specified. In this specification, a numerical range indicated by "greater than" or "less than" means a range that does not include the number as the lower or upper limit. In the numerical ranges described stepwise in this specification, the upper limit of one stepwise numerical range may be replaced with the upper limit of another stepwise numerical range or a value shown in the examples. Also, in the numerical ranges described stepwise in this specification, the lower limit of one stepwise numerical range may be replaced with the lower limit of another stepwise numerical range or a value shown in the examples.

[0030] (1. Humidity control devices) The humidity control device according to an embodiment of the present invention can be suitably used to adjust the indoor humidity in various vehicles such as automobiles. Vehicles are not particularly limited, but include automobiles and trains. Automobiles are not particularly limited, but include gasoline cars, diesel cars, gas-fueled cars using CNG (compressed natural gas) or LNG (liquefied natural gas), fuel cell vehicles, electric vehicles, and plug-in hybrid vehicles. The vehicle air conditioning system according to an embodiment of the present invention can be suitably used in vehicles without internal combustion engines, such as electric vehicles and trains. Furthermore, the humidity control device according to the embodiment of the present invention can be used not only for vehicles but also for adjusting the indoor humidity of buildings such as houses, offices, factories, shops, and warehouses, as well as vehicles such as ships and airplanes.

[0031] Figure 1 is a schematic cross-sectional view of a humidity control device according to an embodiment of the present invention. As shown in Figure 1, the humidity control device 10 according to the embodiment of the present invention comprises a base material portion 110 and an adsorption portion 120 provided on the surface of the base material portion 110. The adsorption section 120 contains an adsorbent capable of adsorbing and desorbing moisture.

[0032] The adsorbent's moisture adsorption amount is measured in the moisture adsorption isotherm when the relative humidity is 20% or higher (i.e., the entire range of relative humidity above 20%). 20 (Hereinafter referred to as “Moisture adsorption amount Ad 20 The amount of water adsorbed (abbreviated as ") is 15% by mass or more, preferably 20% by mass or more, more preferably 23% by mass or more, and even more preferably 25% by mass or more. 20By controlling this, the moisture adsorption efficiency can be increased in air with high relative humidity (specifically, air having a relative humidity of 20% or higher). Therefore, based on the flow direction of air, the moisture adsorption efficiency can be increased in a region with high relative humidity on the upstream side inside the humidity control device 10. Note that the moisture adsorption amount Ad 20 The upper limit of is not particularly limited, but is generally 80% by mass, preferably 60% by mass, and more preferably 40% by mass.

[0033] Here, the moisture adsorption isotherm in the present specification refers to a graph plotting the moisture adsorption amount [% by mass] of an adsorbent when the relative humidity [%] in air is changed in the moisture adsorption phenomenon, and serves as an index indicating the ease of moisture adsorption by the adsorbent at each relative humidity in air. The moisture adsorption isotherm can be measured using a commercially available adsorption isotherm measuring apparatus (BELSORP 18HTII manufactured by MicrotracBEL Corp.). Specifically, the target adsorbent is placed in a measurement cell, and measurement is performed after degassing under reduced pressure at 100°C for about 5 hours. The measurement is performed at 20°C, and other conditions follow the conditions recommended by the adsorption isotherm measuring apparatus.

[0034] The adsorbent has a difference of 5% by mass or more, preferably 8% by mass or more, more preferably 10% by mass or more, and even more preferably 17% by mass or more, between the amount of moisture adsorbed Ad8 at a relative humidity of 8% and the amount of moisture adsorbed Ad1 at a relative humidity of 1% on the moisture adsorption isotherm, i.e., the difference of moisture adsorbed Ad8-Ad1 is 5% by mass or more, preferably 8% by mass or more, more preferably 10% by mass or more, and even more preferably 17% by mass or more. By controlling the difference of moisture adsorbed Ad8-Ad1 within this range, the amount of moisture adsorbed increases between relative humidity of 1% and 8%, thereby increasing the moisture adsorption efficiency in air with low relative humidity (specifically, air with a relative humidity of less than 20%). Therefore, with respect to the direction of airflow, the moisture adsorption efficiency in the low relative humidity region downstream of the humidity control device 10 can be increased. On the other hand, in the regeneration process of the humidity control device 10, moisture is removed by heating the adsorbent contained in the adsorption section 120, but if the amount of moisture adsorbed does not decrease sufficiently at low relative humidity on the moisture adsorption isotherm, the regeneration process will not proceed easily. Therefore, by setting the difference in moisture adsorption amount Ad8-Ad1 within the above range, the amount of moisture adsorbed decreases when the relative humidity is low, thus enabling efficient regeneration. The upper limit of the difference in moisture adsorption amount Ad8-Ad1 is not particularly limited, but is generally 50% by mass, preferably 30% by mass, and more preferably 20% by mass.

[0035] The adsorbent has a difference of Ad5-Ad1 (hereinafter abbreviated as "difference in moisture adsorption amount Ad5-Ad1") between the amount of moisture adsorbed at 5% relative humidity and the amount of moisture adsorbed at 1% relative humidity on a moisture adsorption isotherm, preferably 5% by mass or more, more preferably 6% by mass or more, and even more preferably 8% by mass or more. By controlling the difference in moisture adsorption amount Ad5-Ad1 within this range, the amount of moisture adsorbed increases between 1% and 5% relative humidity, making it easier to stably obtain the effect of increasing the moisture adsorption efficiency in air with low relative humidity (specifically, air with a relative humidity of less than 20%). Furthermore, by setting the difference in moisture adsorption amount Ad5-Ad1 within the above range, the amount of moisture adsorbed decreases at low relative humidity, making it easier for the regeneration process to proceed efficiently. The upper limit of the difference in moisture adsorption amount Ad5-Ad1 is not particularly limited, but is generally 30% by mass, preferably 20% by mass, and more preferably 15% by mass.

[0036] The adsorbent preferably has a difference of 2% by mass or more, more preferably 3% by mass or more, between the amount of moisture adsorbed at 5% relative humidity (Ad5) and the amount of moisture adsorbed at 3% relative humidity (Ad3) on a moisture adsorption isotherm (Ad5-Ad3, hereinafter abbreviated as "difference in moisture adsorption amount Ad5-Ad3"). By controlling the difference in moisture adsorption amount Ad5-Ad3 within this range, the amount of moisture adsorbed increases between 3% and 5% relative humidity, making it easier to stably obtain the effect of increasing the moisture adsorption efficiency in air with low relative humidity (specifically, air with a relative humidity of less than 20%). Furthermore, by setting the difference in moisture adsorption amount Ad5-Ad3 within the above range, the amount of moisture adsorbed decreases at low relative humidity, making it easier for the regeneration process to proceed efficiently. The upper limit of the difference in moisture adsorption amount Ad5-Ad3 is not particularly limited, but is generally 30% by mass, preferably 20% by mass, and more preferably 15% by mass.

[0037] Specific examples of adsorbents are not particularly limited as long as they possess the above-mentioned properties, but include X-type zeolite, Y-type zeolite, A-type zeolite, and MFI-type zeolite. These can be used individually or in combination of two or more types. Furthermore, the water adsorption isotherm of Y-type zeolite changes depending on the molar ratio of SiO2 / Al2O3. From the viewpoint of ensuring the above characteristics, it is preferable that the molar ratio of SiO2 / Al2O3 of Y-type zeolite is 10 or less.

[0038] Here, the moisture adsorption isotherms of several adsorbents are shown in Figures 2A and 2B. Figure 2A shows the moisture adsorption isotherms of adsorbents usable in the present invention, and Figure 2B shows the moisture adsorption isotherms of adsorbents not usable in the present invention. As shown in Figure 2A, the X-type zeolite exhibits the following water adsorption amount Ad in the water adsorption isotherm. 20 The amount of water adsorption is 20% by mass or more, the difference in water adsorption amount Ad8-Ad1 is 8% by mass, the difference in water adsorption amount Ad5-Ad1 is 6% by mass, and the difference in water adsorption amount Ad5-Ad3 is 3% by mass. In addition, the MFI type zeolite has a water adsorption isotherm in which the amount of water adsorption is Ad 20 The amount of water adsorption is 28% by mass or more, the difference in water adsorption amount Ad8-Ad1 is 16% by mass, the difference in water adsorption amount Ad5-Ad1 is 15% by mass, and the difference in water adsorption amount Ad5-Ad3 is 6% by mass. Y-type zeolite (molar ratio of SiO2 / Al2O3 5) shows that in the water adsorption isotherm, the amount of water adsorption is Ad 20 The amount of water adsorption is 31% by mass or more, the difference in water adsorption amount Ad8-Ad1 is 23% by mass, the difference in water adsorption amount Ad5-Ad1 is 22% by mass, and the difference in water adsorption amount Ad5-Ad3 is 2% by mass. Y-type zeolite (molar ratio of SiO2 / Al2O3 10) shows that the amount of water adsorption is 31% by mass or more, the difference in water adsorption amount Ad8-Ad1 is 23% by mass, the difference in water adsorption amount Ad5-Ad1 is 22% by mass, and the difference in water adsorption amount Ad5-Ad3 is 2% by mass. 20 The percentage of water adsorbed is 20% by mass or more, the difference in water adsorbed amount between Ad8 and Ad1 is 12% by mass, the difference in water adsorbed amount between Ad5 and Ad1 is 10% by mass, and the difference in water adsorbed amount between Ad5 and Ad3 is 4% by mass.

[0039] On the other hand, as shown in Figure 2B, AFI-type zeolite exhibits the following water adsorption amount Ad in the water adsorption isotherm. 20 The amount of water adsorption is 17% by mass or more, the difference in water adsorption amount Ad8-Ad1 is 1% by mass, the difference in water adsorption amount Ad5-Ad1 is 1% by mass, and the difference in water adsorption amount Ad5-Ad3 is 0% by mass. In addition, for type A silica gel, the amount of water adsorption is measured on the water adsorption isotherm is 17% by mass or more. 20The amount of water adsorbent is 10% by mass or more, the difference in water adsorption amount Ad8-Ad1 is 3% by mass, the difference in water adsorption amount Ad5-Ad1 is 2% by mass, and the difference in water adsorption amount Ad5-Ad3 is 1% by mass. The polymer adsorbent has a water adsorption isotherm in which the amount of water adsorbed is Ad 20 The amount of water adsorption is 9% by mass or more, the difference in water adsorption amount Ad8-Ad1 is 3% by mass, the difference in water adsorption amount Ad5-Ad1 is 2% by mass, and the difference in water adsorption amount Ad5-Ad3 is 1% by mass. Y-type zeolite (molar ratio of SiO2 / Al2O3 20) shows that the amount of water adsorption is 9% by mass or more, the difference in water adsorption amount Ad8-Ad1 is 3% by mass, the difference in water adsorption amount Ad5-Ad1 is 2% by mass, and the difference in water adsorption amount Ad5-Ad3 is 1% by mass. 20 The difference in water adsorption is 3% by mass or more, the difference in water adsorption between Ad8 and Ad1 is 2% by mass, the difference in water adsorption between Ad5 and Ad1 is 2% by mass, and the difference in water adsorption between Ad5 and Ad3 is 1% by mass. Note that the moisture adsorption isotherms for each of the above adsorbents are just examples, and the amount of moisture adsorbed may vary depending on the source of each adsorbent. 20 It should be noted that the values ​​of the difference in water adsorption amounts, Ad8-Ad1, Ad5-Ad1, and Ad5-Ad3, may fluctuate.

[0040] The base material 110 is not particularly limited and can be of various shapes. For example, the base material 110 can be plate-shaped (sheet-shaped), honeycomb-shaped, pellet-shaped, etc. If the base material 110 is plate-shaped (sheet-shaped), it may have a pleated folded structure. Also, if the base material 110 is plate-shaped or pellet-shaped, the base material 110 equipped with the adsorption part 120 can be filled into the humidity control device 10 and used.

[0041] Here, Figure 3A shows a schematic cross-section of the humidity control device 10 parallel to the flow path direction when the base material 110 is a honeycomb structure, and Figure 3B shows a schematic cross-section of the air conditioning device in Figure 3A along the line a-a'. As shown in Figures 3A and 3B, the honeycomb structure 111 has an outer peripheral wall 112 and partition walls 116 disposed inside the outer peripheral wall 112, which partition a plurality of cells 115 that form air passages extending from a first end face 113 to a second end face 114. The adsorption layer 121, which serves as the adsorption part 120, is provided on the surface of the partition walls 116. The adsorption layer 121 may also be provided on the surface of the outer peripheral wall 112 facing the cells 115. Furthermore, the honeycomb structure 111 can be provided with a pair of electrodes 117, 118, and terminals 119 connected to the pair of electrodes 117, 118.

[0042] <Honeycomb structure 111> The outer diameter of the honeycomb structure 111 is not particularly limited. For example, the outer shape of the cross-section perpendicular to the flow direction (the direction in which the cells 115 extend) of the honeycomb structure 111 can be a polygon such as a quadrilateral (rectangle, square), pentagon, hexagon, heptagon, or octagon, or a circle or oval shape (egg, ellipse, oblong, rounded rectangle, etc.). The end faces (first end face 113 and second end face 114) have the same shape as the cross-section. Furthermore, if the cross-section and end faces are polygonal, the corners may be chamfered.

[0043] The shape of the cell 115 is not particularly limited, but in a cross-section perpendicular to the flow direction of the honeycomb structure 111, it can be a polygon such as a square, pentagon, hexagon, heptagon, or octagon, or a circle or oval shape. These shapes may be single or a combination of two or more. Among these shapes, square or hexagonal is preferred. By providing cells 115 of such shape, the pressure loss when air flows can be reduced.

[0044] The honeycomb structure 111 may be a honeycomb joint having a plurality of honeycomb segments and a joining layer that joins the outer periphery sides of the plurality of honeycomb segments. By using a honeycomb joint, it is possible to increase the total cross-sectional area of ​​the cells 115, which are important for securing the airflow rate (flow velocity), while suppressing the occurrence of cracks. The bonding layer can be formed using a bonding material. The bonding material is not particularly limited, but a paste made by adding a solvent such as water to ceramic raw materials can be used. The bonding material may contain a material having PTC properties, or it may contain the same material as the outer periphery wall 112 and the partition wall 116. In addition to its role in bonding the honeycomb segments together, the bonding material can also be used as an outer periphery coating material after the honeycomb segments have been bonded.

[0045] From the viewpoint of ensuring the strength of the honeycomb structure 111, reducing pressure loss when air passes through the cells 115, ensuring the amount of functional material carried, and ensuring the contact area with the air flowing inside the cells 115, it is desirable to suitably combine the thickness of the partition wall 116, the cell density, and the cell pitch (or the opening ratio of the cells 115). In this specification, cell density is a value obtained by dividing the number of cells by the area of ​​one end face (first end face 113 or second end face 114) of the honeycomb structure 111 (the total area of ​​the partition wall 116 and cells 115 excluding the outer peripheral wall 112). In this specification, cell pitch refers to a value obtained by the following calculation. First, the area per cell is calculated by dividing the area of ​​one end face of the honeycomb structure 111 (first end face 113 or second end face 114) (the total area of ​​the partition wall 116 and cells 115 excluding the outer perimeter wall 112) by the number of cells. Next, the square root of the area per cell is calculated and this is defined as the cell pitch. In this specification, the aperture ratio of cell 115 is the value obtained by dividing the total area of ​​cells 115 partitioned by partition walls 116 in a cross section perpendicular to the flow direction of the honeycomb structure 111 by the area of ​​one end face (first end face 113 or second end face 114) (the total area of ​​partition walls 116 and cells 115 excluding the outer peripheral wall 112). Note that the pair of electrodes 117, 118 and the adsorption layer 121 are not considered when calculating the aperture ratio of cell 115.

[0046] In an embodiment advantageous in terms of supporting a sufficient amount of functional material, the thickness of the partition wall 116 is 0.300 mm or less, and the cell density is 100 cells / cm³. 2The following conditions apply, and the cell pitch is 1.0 mm or more. In a preferred embodiment, the thickness of the partition wall 116 is 0.200 mm or less, and the cell density is 70 cells / cm³. 2 The following conditions apply, and the cell pitch is 1.2 mm or more. In a more preferred embodiment, the thickness of the partition wall 116 is 0.130 mm or less, and the cell density is 65 cells / cm³. 2 The following conditions apply, and the cell pitch is 1.3 mm or more.

[0047] From the viewpoint of ensuring the strength of the honeycomb structure 111 and keeping electrical resistance low, the lower limit of the thickness of the partition wall 116 is preferably 0.010 mm or more, more preferably 0.020 mm or more, and even more preferably 0.030 mm or more. From the viewpoint of ensuring the strength of the honeycomb structure 111, keeping electrical resistance low, and increasing the surface area to promote reaction, adsorption, and desorption, the lower limit of the cell density is 30 cells / cm². 2 Preferably, it is 35 cells / cm 2 It is more preferable that the rate is 40 cells / cm² or higher. 2 It is even more preferable that the above conditions are met. From the viewpoint of ensuring the strength of the honeycomb structure 111, keeping electrical resistance low, and increasing the surface area to promote reaction, adsorption, and desorption, the upper limit of the cell pitch is preferably 2.0 mm or less, more preferably 1.8 mm or less, and even more preferably 1.6 mm or less.

[0048] In an embodiment advantageous in terms of achieving both reduced pressure loss and maintained strength, the thickness of the partition wall 116 is 0.08 to 0.36 mm, and the cell density is 2.54 to 140 cells / cm³. 2 The opening ratio of cell 115 is 0.70 or higher. In a preferred embodiment, the thickness of the partition wall 116 is 0.09 to 0.35 mm, and the cell density is 15 to 100 cells / cm³. 2 The opening ratio of cell 115 is 0.80 or higher. In a more preferred embodiment, the thickness of the partition wall 116 is 0.14 to 0.30 mm, and the cell density is 20 to 90 cells / cm³. 2 The aperture ratio of cell 115 is 0.85 or higher.

[0049] From the viewpoint of ensuring the strength of the honeycomb structure 111, the upper limit of the opening ratio of the cells 115 is preferably 0.94 or less, more preferably 0.92 or less, and even more preferably 0.90 or less.

[0050] The thickness of the outer periphery wall 112 is not particularly limited, but is preferably determined based on the following considerations. First, from the viewpoint of reinforcing the honeycomb structure 111, the thickness of the outer periphery wall 112 is preferably 0.05 mm or more, more preferably 0.06 mm or more, and even more preferably 0.08 mm or more. On the other hand, from the viewpoint of increasing electrical resistance to suppress initial current and reducing pressure loss when air flows, the thickness of the outer periphery wall 112 is preferably 1.0 mm or less, more preferably 0.5 mm or less, even more preferably 0.4 mm or less, and even more preferably 0.3 mm or less. In this specification, the thickness of the outer peripheral wall 112 refers to the length in the direction normal to the side surface, from the boundary between the outer peripheral wall 112 and the outermost cell 115 or partition wall 116 to the side surface of the honeycomb structure 111, in a cross section perpendicular to the flow direction.

[0051] The length of the honeycomb structure 111 in the flow direction and the cross-sectional area perpendicular to the flow direction can be adjusted to the required size of the humidity control device 10 and are not particularly limited. For example, when used in a compact humidity control device 10 while ensuring a predetermined function, the honeycomb structure 111 may have a length of 2 to 20 mm in the flow direction and a cross-sectional area perpendicular to the flow direction of 10 cm². 2 The above is possible. Note that there is no particular upper limit to the cross-sectional area perpendicular to the flow direction, but for example, 300 cm². 2 The following applies:

[0052] The partition walls 116 constituting the honeycomb structure 111 are made of a material capable of generating heat when an electric current is passed through them, and more preferably, they are made of a material having PTC properties. If necessary, the outer peripheral wall 112 may also be made of a material having PTC properties similar to the partition walls 116. With this configuration, the adsorption layer 121 can be directly heated by heat transfer from the heat-generating partition walls 116 (and the outer peripheral wall 112 if necessary). Furthermore, materials having PTC properties have the characteristic that when the temperature rises and exceeds the Curie point, the resistance value increases rapidly and it becomes difficult for electricity to flow. Therefore, when the partition walls 116 (and the outer peripheral wall 112 if necessary) become hot, the current flowing through them is limited, so excessive heat generation in the honeycomb structure 111 is suppressed. Consequently, it is also possible to suppress thermal degradation of the adsorption layer 121 caused by excessive heat generation.

[0053] From the viewpoint of obtaining appropriate heat generation, the lower limit of the volume resistivity of a PTC-type material at 25°C is preferably 0.5 Ω·cm or more, more preferably 1 Ω·cm or more, and even more preferably 5 Ω·cm or more. From the viewpoint of generating heat with a low drive voltage, the upper limit of the volume resistivity of a PTC-type material at 25°C is preferably 30 Ω·cm or less, more preferably 18 Ω·cm or less, and even more preferably 16 Ω·cm or less. In this specification, the volume resistivity of a PTC-type material at 25°C is measured in accordance with JIS K6271:2008.

[0054] From the viewpoint of being electrically conductive and having PTC characteristics, it is preferable that the outer periphery wall 112 and the partition wall 116 are made of a material mainly composed of barium titanate (BaTiO3). Furthermore, it is more preferable that this material is a ceramic material mainly composed of barium titanate (BaTiO3)-based crystalline particles in which a portion of Ba is replaced with rare earth elements. In this specification, "main component" means a component whose proportion in the total component exceeds 50% by mass. The content of BaTiO3-based crystalline particles can be determined by fluorescent X-ray analysis. Other crystalline particles can also be measured in the same manner.

[0055] The compositional formula for BaTiO3-based crystal grains in which some of the Ba is replaced by rare earth elements is (Ba 1-x A x It can be represented as TiO3. In the empirical formula, A represents one or more rare earth elements, and 0.0001 ≤ x ≤ 0.010. A is not particularly limited as long as it is a rare earth element, but is preferably one or more selected from the group consisting of La, Ce, Pr, Nd, Eu, Gd, Dy, Ho, Er, Y, and Yb, and is more preferably La. x is preferably 0.001 or more, more preferably 0.0015 or more, from the viewpoint of suppressing excessively high electrical resistance at room temperature. On the other hand, x is preferably 0.009 or less, from the viewpoint of suppressing excessively high electrical resistance at room temperature due to insufficient sintering. The content of BaTiO3-based crystalline particles in ceramics, in which a portion of Ba is substituted with rare earth elements, is not particularly limited as long as it constitutes the main component, but is preferably 90% by mass or more, more preferably 92% by mass or more, and even more preferably 94% by mass or more. The upper limit of the content of BaTiO3-based crystalline particles is not particularly limited, but is generally 99% by mass, preferably 98% by mass.

[0056] From the viewpoint of reducing environmental impact, it is desirable that the materials used for the outer perimeter wall 112 and the partition wall 116 be substantially lead-free (Pb). Specifically, the Pb content of the outer perimeter wall 112 and the partition wall 116 is preferably 0.01% by mass or less, more preferably 0.001% by mass or less, and even more preferably 0% by mass. A low Pb content allows, for example, heated air to be safely directed at living organisms such as humans by contacting the heat-generating partition wall 116. In addition, the Pb content of the outer perimeter wall 112 and the partition wall 116, when converted to PbO, is preferably less than 0.03% by mass, more preferably less than 0.01% by mass, and even more preferably 0% by mass. The lead content can be determined by ICP-MS (inductively coupled plasma mass spectrometry).

[0057] Preferably, the Curie point of the materials constituting the outer perimeter wall 112 and the partition wall 116 is within the temperature range where the resistance value is more than twice the resistance value at room temperature (25°C). If the Curie point is within such a temperature range, the current flowing through them is limited when the humidity control device 10 becomes hot, so excessive heat generation of the humidity control device 10 is efficiently suppressed. Therefore, thermal degradation of the adsorption layer 121 caused by excessive heat generation can be suppressed. The lower limit of the Curie point of the materials constituting the outer peripheral wall 112 and the partition wall 116 is preferably 80°C or higher, more preferably 100°C or higher, even more preferably 110°C or higher, and particularly preferably 125°C or higher, from the viewpoint of efficiently heating the adsorption layer 121. The upper limit of the Curie point is preferably 200°C or lower, more preferably 190°C or lower, even more preferably 180°C or lower, and particularly preferably 150°C or lower, from the viewpoint of safety as a component placed in or near the vehicle compartment.

[0058] The Curie points of the materials constituting the outer perimeter wall 112 and the partition wall 116 can be adjusted by the type and amount of sifter added. For example, the Curie point of barium titanate (BaTiO3) is approximately 120°C, but by substituting some of the Ba and Ti with one or more of Sr, Sn, and Zr, the Curie point can be shifted to a lower temperature.

[0059] In this specification, the Curie point is measured by the following method: The sample is mounted in a sample holder for measurement and placed in a measuring chamber (e.g., MINI-SUBZERO MC-810P, manufactured by ESPEC Corporation). The change in the electrical resistance of the sample with respect to temperature changes as the temperature is raised from 10°C is measured using a DC resistance meter (e.g., Multimeter 3478A, manufactured by Hewlett-Packard Japan, G.K.). The Curie point is defined as the temperature at which the resistance value becomes twice the resistance value at room temperature (25°C) as shown in the electrical resistance-temperature plot obtained from the measurement.

[0060] <Pair of electrodes 117, 118> The positions of the pair of electrodes 117 and 118 are not particularly limited, but as shown in Figure 3A, they can be provided on the first end face 113 and the second end face 114 of the honeycomb structure 111. Alternatively, the pair of electrodes 117 and 118 may be provided on the outer peripheral wall 112 of the honeycomb structure 111 that is parallel to the direction in which the cells 115 extend. By applying a voltage between the pair of electrodes 117 and 118, it is possible to generate heat in the honeycomb structure 111 through Joule heating.

[0061] The pair of electrodes 117, 118 are not particularly limited, but for example, a metal or alloy containing at least one selected from Cu, Ag, Al, Ni, and Si can be used. Alternatively, an ohmic electrode capable of ohmic contact with the outer peripheral wall 112 and / or partition wall 116 having PTC characteristics can be used. For example, an ohmic electrode can be used that contains at least one selected from Al, Au, Ag, and In as a base metal and at least one selected from Ni, Si, Zn, Ge, Sn, Se, and Te for n-type semiconductors as a dopant. Furthermore, the pair of electrodes 117, 118 may have a single-layer structure or a multilayer structure of two or more layers. If the pair of electrodes 117, 118 has a multilayer structure of two or more layers, the material of each layer may be the same type or different types.

[0062] The thickness of the pair of electrodes 117, 118 can be appropriately set depending on the method of forming the pair of electrodes 117, 118. Methods for forming the pair of electrodes 117, 118 include metal deposition methods such as sputtering, vapor deposition, electrolytic deposition, and chemical deposition. Alternatively, the pair of electrodes 117, 118 can be formed by applying electrode paste and then baking it, or by thermal spraying. Furthermore, the pair of electrodes 117, 118 may be formed by joining metal plates or alloy plates.

[0063] The thickness of the pair of electrodes 117 and 118 is preferably about 5 to 30 μm for electrode paste baking, about 100 to 1000 nm for dry plating such as sputtering and vapor deposition, about 10 to 100 μm for thermal spraying, and about 5 to 30 μm for wet plating such as electroplating and chemical deposition. Furthermore, when joining metal plates or alloy plates, it is preferable that their thickness be about 5 to 100 μm.

[0064] <Terminal 119> Terminal 119 is connected to a pair of electrodes 117 and 118 and is provided on at least a portion of the pair of electrodes 117 and 118. Providing terminal 119 facilitates connection to an external power supply. Terminal 119 is connected to a conductor connected to the external power supply.

[0065] The material of terminal 119 is not particularly limited, but for example, it can be a metal. As the metal, elemental metals and alloys can be used, but from the viewpoint of corrosion resistance, electrical resistivity and coefficient of linear expansion, it is preferable to use an alloy containing at least one selected from the group consisting of Cr, Fe, Co, Ni, Cu, Al, and Ti, and stainless steel, Fe-Ni alloy, and phosphor bronze are more preferable.

[0066] The size and shape of the terminal 119 are not particularly limited. For example, as shown in Figure 3A, the terminal 119 can be provided over the entire length of the pair of electrodes 117 and 118 on the outer peripheral wall 112. Alternatively, the terminal 119 may be provided on a portion of the pair of electrodes 117 and 118 on the outer peripheral wall 112, or it may be provided so as to extend outward from the outer edge of the pair of electrodes 117 and 118 on the outer peripheral wall 112. Furthermore, the terminal 119 may be provided on a portion of the pair of electrodes 117 and 118 on the partition wall 116, or it may be provided so as to block a portion of the cells 115. Furthermore, the thickness of the terminal 119 is not particularly limited, but is, for example, 0.01 to 10 mm, typically 0.05 to 5 mm.

[0067] The method of connecting terminal 119 to the pair of electrodes 117 and 118 is not particularly limited as long as they are electrically connected, and can be done by means of diffusion bonding, a mechanical pressurizing mechanism, welding, etc.

[0068] <Adsorption layer 121> The adsorption layer 121 is a layer containing an adsorbent. The adsorption layer 121 can be provided on the surface of the partition wall 116 (or, in the case of the outermost cell 115, the partition wall 116 that partitions the outermost cell 115 and the outer peripheral wall 112). By providing the adsorption layer 121 in this way, it becomes easier to adsorb moisture during the adsorption process, and it becomes easier to heat the adsorption layer 121 during the regeneration process, thereby allowing the function of the adsorption layer 121 to be regenerated.

[0069] The adsorption layer 121 may be capable of adsorbing carbon dioxide and / or volatile components in addition to moisture. If the adsorption layer 121 is capable of adsorbing carbon dioxide and volatile components in addition to moisture, an air purification effect can be obtained.

[0070] The volatile components contained in the air inside a vehicle include, for example, volatile organic compounds (VOCs) and odor components other than VOCs. Specific examples of volatile components include ammonia, acetic acid, isovaleric acid, nonenal, formaldehyde, toluene, xylene, paradichlorobenzene, ethylbenzene, styrene, chlorpyrifos, di-n-butyl phthalate, tetradecane, di-2-ethylhexyl phthalate, diazinon, acetaldehyde, and N-methylcarbamate-2-(1-methylpropyl)phenyl.

[0071] The adsorption layer 121 may contain a catalyst. By including a catalyst, oxidation-reduction reactions can be promoted to purify carbon dioxide and / or volatile components. Examples of catalysts with such functions include metal catalysts such as Pt, Pd, and Ag, and oxide catalysts such as CeO2 and ZrO2. The catalyst may be used alone or in combination of two or more types. Furthermore, the catalyst can be used in combination with the functional materials described above.

[0072] The thickness of the adsorption layer 121 can be determined according to the size of the cell 115 and is not particularly limited. For example, from the viewpoint of ensuring sufficient contact with air, the thickness of the adsorption layer 121 is preferably 20 μm or more, more preferably 25 μm or more, and even more preferably 30 μm or more. On the other hand, from the viewpoint of suppressing the peeling of the adsorption layer 121 from the partition wall 116 and the outer peripheral wall 112, the thickness of the adsorption layer 121 is preferably 400 μm or less, more preferably 380 μm or less, and even more preferably 350 μm or less.

[0073] The thickness of the adsorption layer 121 is measured using the following procedure. An arbitrary cross section parallel to the flow direction of the honeycomb structure 111 is cut out, and a cross-sectional image at approximately 50x magnification is obtained using a scanning electron microscope or similar device. This cross section is also taken so that it passes through the centroid position of a cross section perpendicular to the flow direction of the honeycomb structure 111. For each adsorption layer 121 visible in the cross-sectional image, the thickness is calculated by dividing the cross-sectional area by the length of the cell 115 in the flow direction. This calculation is performed for all adsorption layers 121 visible in the cross-sectional image, and the overall average value is taken as the thickness of the adsorption layer 121.

[0074] From the viewpoint of performing the desired function within the humidity control device 10, the amount of the adsorption layer 121 is preferably 50 to 500 g / L, more preferably 100 to 400 g / L, and even more preferably 150 to 350 g / L, relative to the volume of the honeycomb structure 111. The volume of the honeycomb structure 111 is determined by the external dimensions of the honeycomb structure 111.

[0075] <Manufacturing method for humidity control device 10> The method for manufacturing the humidity control device 10 is not particularly limited and can be carried out in accordance with known methods. Below, a method for manufacturing the humidity control device 10 using a honeycomb structure 111 as the base material 110 will be described exemplified. The manufacturing method for the honeycomb structure 111 that constitutes the humidity control device 10 includes a molding step and a firing step. In the molding process, a clay mold containing ceramic raw materials including BaCO3 powder, TiO2 powder, and rare earth nitrate or hydroxide powder is molded to produce a honeycomb molded body with a relative density of 60% or more. Ceramic raw materials can be obtained by dry mixing each powder to achieve the desired composition. The clay can be obtained by adding a dispersion medium, binder, plasticizer, and dispersant to ceramic raw materials and kneading them together. The clay may also contain additives such as sifters, metal oxides, property improvers, and conductive powders as needed. The amount of components other than ceramic raw materials is not particularly limited, as long as it is such that the relative density of the honeycomb molded body is 60% or more.

[0076] Here, in this specification, "relative density of the honeycomb molded body" means the ratio of the density of the honeycomb molded body to the true density of the entire ceramic raw material. Specifically, it can be calculated by the following formula. Relative density (%) of honeycomb molded material = Density (g / cm³) of honeycomb molded material 3 ) / True density of the entire ceramic raw material (g / cm³) 3 ) × 100 The density of a honeycomb molded body can be measured by the Archimedes method using pure water as the medium. The true density of the entire ceramic material is calculated by adding the mass of each material (g) and then adding the actual volume of each material (cm³). 3 It can be found by dividing by ).

[0077] Examples of dispersion media include water, or a mixed solvent of water and an organic solvent such as alcohol, but water is particularly suitable.

[0078] Examples of binders include organic binders such as methylcellulose, hydroxypropoxylcellulose, hydroxyethylcellulose, carboxymethylcellulose, and polyvinyl alcohol. In particular, the combined use of methylcellulose and hydroxypropoxylcellulose is preferred. The binder may be used alone or in combination of two or more types, but it is preferable that it does not contain alkali metal elements.

[0079] Examples of plasticizers include polyoxyalkylene alkyl ethers, polycarboxylic acid polymers, and alkyl phosphate esters.

[0080] Dispersants that can be used include surfactants such as polyoxyalkylene alkyl ethers, ethylene glycol, dextrin, fatty acid soaps, and polyalcohols. Dispersants may be used individually or in combination of two or more types.

[0081] Honeycomb molded bodies can be manufactured by extruding clay. During extrusion molding, a die with the desired overall shape, cell shape, partition wall thickness, and cell density can be used.

[0082] The relative density of the honeycomb molded body obtained by extrusion molding is 60% or more, preferably 65% ​​or more. By controlling the relative density of the honeycomb molded body within this range, it is possible to densify the honeycomb molded body and reduce its electrical resistance at room temperature. The upper limit of the relative density of the honeycomb molded body is not particularly limited, but is generally 80%, preferably 75%.

[0083] The honeycomb molded body can be dried before the firing process. The drying method is not particularly limited, but conventional known drying methods such as hot air drying, microwave drying, dielectric drying, reduced pressure drying, vacuum drying, and freeze drying can be used. Among these, a drying method combining hot air drying with microwave drying or dielectric drying is preferred because it can dry the entire molded body quickly and uniformly.

[0084] The firing process includes maintaining the temperature at 1150-1250°C, then increasing the temperature to a maximum of 1360-1430°C at a heating rate of 20-600°C / hour, and maintaining the temperature for 0.5-10 hours. By holding the honeycomb molded body at a maximum temperature of 1360 to 1430°C for 0.5 to 10 hours, a honeycomb structure 111 mainly composed of BaTiO3-based crystalline grains in which some of the Ba is replaced by rare earth elements can be obtained. Furthermore, by maintaining the temperature at 1150-1250°C, the Ba2TiO4 crystal particles generated during the firing process are more easily removed, thereby densifying the honeycomb structure 111. Furthermore, by setting the heating rate from 1150-1250°C to the maximum temperature of 1360-1430°C to 20-600°C / hour, 1.0-10.0 mass% of Ba6Ti 17 O 40 Crystal particles can be generated in the honeycomb structure 111.

[0085] The holding time at 1150-1250°C is not particularly limited, but is preferably 0.5-10 hours. This holding time makes it easier to stably remove the Ba2TiO4 crystal grains generated during the firing process.

[0086] The firing process preferably includes holding the temperature at 900-950°C for 0.5-5 hours during the heating phase. Holding the temperature at 900-950°C for 0.5-5 hours allows BaCO3 to decompose efficiently, making it easier to obtain a honeycomb structure 111 having a predetermined composition.

[0087] Furthermore, a degreasing process may be performed before the firing process to remove the binder. The atmosphere during the degreasing process is preferably atmospheric air to completely decompose the organic components. Furthermore, the atmosphere during the firing process is preferably an atmospheric environment, from the viewpoint of controlling electrical properties and reducing manufacturing costs. The furnace used in the firing and degreasing processes is not particularly limited, but electric furnaces, gas furnaces, etc., can be used.

[0088] A pair of electrodes 117 and 118 are formed on the honeycomb structure 111 obtained in this manner. The pair of electrodes 117 and 118 can be formed by metal deposition methods such as sputtering, vapor deposition, electrolysis, or chemical deposition. Alternatively, the pair of electrodes 117 and 118 can be formed by applying an electrode paste and then baking it. Furthermore, the pair of electrodes 117 and 118 can also be formed by thermal spraying. The pair of electrodes 117 and 118 may consist of a single layer, or it may consist of multiple electrode layers with different compositions. The following describes typical methods for forming the pair of electrodes 117 and 118.

[0089] First, an electrode slurry containing electrode material, an organic binder, and a dispersion medium is prepared and applied to the first end face 113 or the second end face 114 of the honeycomb structure 111. The dispersion medium can be water, an organic solvent (e.g., toluene, xylene, ethanol, n-butanol, ethyl acetate, butyl acetate, terpineol, dihydroterpineol, texanol, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether), or a mixture thereof. Excess slurry around the outer circumference of the honeycomb structure 111 is removed by blowing and wiping. Then, a pair of electrodes 117, 118 can be formed on the first end face 113 or the second end face 114 of the honeycomb structure 111 by drying the slurry. Drying can be carried out by heating the honeycomb structure 111 to a temperature of, for example, 120 to 600°C. The series of steps—coating, slurry removal, and drying—may be performed only once, but by repeating them multiple times, a pair of electrodes 117, 118 of the desired thickness can be provided.

[0090] Next, the terminal 119 is placed at a predetermined position on the pair of electrodes 117 and 118, and the pair of electrodes 117 and 118 are connected to the terminal 119. The method described above can be used to connect the pair of electrodes 117 and 118 to the terminal 119. Note that the terminal 119 may be installed after the adsorption layer 121 described below has been formed.

[0091] Next, an adsorption layer 121 is formed on the surface of the honeycomb structure 111, such as the partition walls 116. The method for forming the adsorption layer 121 is not particularly limited, but for example, it can be formed by the following steps: The honeycomb structure 111 is immersed in a slurry containing an adsorbent, an organic binder, and a dispersion medium for a predetermined time, and excess slurry from the end faces and outer circumference of the honeycomb structure 111 is removed by blowing and wiping. The dispersion medium can be water, an organic solvent (e.g., toluene, xylene, ethanol, n-butanol, ethyl acetate, butyl acetate, terpineol, dihydroterpineol, texanol, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether) or a mixture thereof. After that, the adsorption layer 121 can be formed on the surface of the partition wall 116 or the like by drying the slurry. Drying can be carried out, for example, by heating the honeycomb structure 111 to a temperature of about 120 to 600°C. The series of steps—immersion, slurry removal, and drying—may be performed only once, but by repeating them multiple times, an adsorption layer 121 of the desired thickness can be formed on the surface of the partition wall 116 or the like.

[0092] (2. Humidity control system) A humidity control system according to an embodiment of the present invention comprises a flow path through which air can circulate and a humidity control device 10 disposed within the flow path. The humidity control system according to the embodiment of the present invention is not particularly limited as long as it has the above configuration, and can be applied to existing humidity control systems except for the use of the humidity control device 10. An example of a humidity control system according to the embodiment of the present invention will be described below.

[0093] Figure 4 is a schematic diagram of the overall configuration of a humidity control system according to an embodiment of the present invention. As shown in Figure 4, the humidity control system 20 according to an embodiment of the present invention comprises an air conditioning duct 210, a humidity control device 10, a power supply 220, a valve 230, a ventilator 240, and a control unit 250.

[0094] <Air conditioning duct 210> The air conditioning duct 210 is a passage through which air can flow, and constitutes a passage through which air can flow. The upstream side of the air conditioning duct 210 is connected to the interior or exterior (particularly in the case of a vehicle, to the vehicle compartment or an outside air inlet). The air conditioning duct 210 allows air to flow in from the interior or exterior, and also allows air that has passed through the humidity control device 10 to flow into the interior or out to the exterior. Therefore, it is preferable that the air conditioning duct 210 is branched downstream of the humidity control device 10 into a first passage 211 that allows air to flow into the interior and a second passage 212 that discharges air to the exterior.

[0095] The air conditioning duct 210 may have a valve 230 that can switch the airflow between a first flow path 211 and a second flow path 212. The valve 230 is not particularly limited as long as it is electrically driven and has the function of switching the flow path, and solenoid valves and electric valves can be used. For example, the valve 230 includes an opening and closing door supported on a rotating shaft and an actuator such as a motor that rotates the rotating shaft. The actuator can be configured to be controllable by a control unit 250.

[0096] <Humidity control device 10> The humidity control device 10 is placed inside the air conditioning duct 210. The number of humidity control devices 10 placed inside the air conditioning duct 210 may be one or more. If multiple humidity control devices 10 are provided, they may be arranged in parallel or in series with respect to the airflow circulating inside the air conditioning duct 210.

[0097] <Power supply 220> The power supply 220 is for applying voltage to the humidity control device 10 (particularly the pair of electrodes 117 and 118). The power supply 220 is electrically connected to the control unit 250 and adjusts the voltage applied to the pair of electrodes 117 and 118 according to instructions from the control unit 250. The power source 220 is not particularly limited and can use batteries, etc.

[0098] <Ventilator 240> The ventilator 240 is used to draw air from indoors or outdoors into the humidity control device 10 and is located within the air conditioning duct 210. The location of the ventilator 240 is not particularly limited, but for example, as shown in Figure 4, it may be located upstream of the humidity control device 10 or downstream of the humidity control device 10. Furthermore, the ventilator 240 is electrically connected to the control unit 250, and controls the airflow velocity by adjusting its rotation speed according to instructions from the control unit 250.

[0099] <Control Unit 250> The control unit 250 is connected to the power supply 220, valve 230, ventilator 240, etc., and can control these. Specifically, by controlling the power supply 220, the control unit 250 can control the voltage applied to the pair of electrodes 117 and 118 of the humidity control device 10, thereby adjusting the heating state of the honeycomb structure 111. The control unit 250 can also control the valve 230 so that air flows through the first flow path 211 or the second flow path 212. Furthermore, by adjusting the rotation speed of the ventilator 240, the control unit 250 can control the flow velocity of the air circulating in the air conditioning duct 210.

[0100] The control unit 250 is not particularly limited, but is generally an ECU (Engine (electronic) Control Unit). The ECU includes a CPU that performs various calculation processes, a ROM that stores programs and data necessary for its control, a RAM that temporarily stores the results of calculations performed by the CPU, and input / output ports for inputting and outputting signals to and from the outside.

[0101] The control unit 250 can perform an adsorption process by turning off the voltage applied from the power supply 220 and switching the valve 230 so that the air flowing through the air conditioning duct 210 passes through the first flow path 211, and a regeneration process by turning on the voltage applied from the power supply 220 and switching the valve 230 so that the air flowing through the air conditioning duct 210 passes through the second flow path 212. By controlling it in this way, the adsorption process and the regeneration process can be easily performed.

[0102] In the adsorption process, the control unit 250 controls the process as described above, thereby adsorbing moisture from the air flowing in from inside or outside the room. At this time, the honeycomb structure 111 of the humidity control device 10 is not heated. Specifically, air from inside or outside the room flows into the humidity control device 10 through the air conditioning duct 210, and the moisture contained in the air is adsorbed. The air from which moisture has been captured is then returned to the room through the first flow path 211.

[0103] During the regeneration process, the adsorption section 120 (adsorption layer 121) of the humidity control device 10 is regenerated by controlling it as described above in the control unit 250. At this time, the honeycomb structure 111 of the humidity control device 10 is heated. Specifically, air from inside or outside the room flows into the humidity control device 10 through the air conditioning duct 210, and as it passes through the humidity control device 10, it detaches the moisture adsorbed on the adsorption section 120 (adsorption layer 121). The moisture-containing air is then discharged outside through the second flow path 212.

[0104] When the humidity control system 20 is for a vehicle, it is desirable to position the humidity control device 10 close to the vehicle interior in order to stably perform the above control. Therefore, from the viewpoint of preventing electric shock, it is preferable that the drive voltage of the humidity control device 10 be 60V or less. The honeycomb structure 111 used in the humidity control device 10 has low electrical resistance at room temperature, so it is possible to heat the honeycomb structure 111 at this low drive voltage. The lower limit of the drive voltage is not particularly limited, but it is preferable to be 10V or more. If the drive voltage is less than 10V, the current when heating the honeycomb structure 111 will be large, so it will be necessary to use thicker wires. [Examples]

[0105] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way by these examples.

[0106] <Fabrication of humidity control devices> BaCO3 powder, TiO2 powder, and La(NH3)3·6H2O powder were prepared as ceramic raw materials. These powders were weighed to obtain a predetermined composition after firing and dry-mixed to obtain a mixed powder. Dry mixing was carried out for 30 minutes. Next, to 100 parts by mass of the obtained mixed powder, water, binder, plasticizer, and dispersant were added in appropriate amounts in the range of 3 to 30 parts by mass in total, so that a ceramic molded body with a relative density of 64.8% after extrusion molding would be obtained, and the mixture was kneaded to obtain clay. Methylcellulose was used as the binder. Polyoxyalkylene alkyl ether was used as the plasticizer and dispersant.

[0107] Next, the obtained clay was fed into an extrusion molding machine and extruded using a predetermined die so that, after firing, it would form a honeycomb structure with the shape shown below. Cross-sectional and end face shapes of the honeycomb structure perpendicular to the flow direction: quadrilateral Shape of the cell cross-section perpendicular to the flow direction: quadrilateral Partition wall thickness: 0.100 mm Outer wall thickness: 0.2 mm Cell density: 80 cells / cm 2 Cell pitch: 1.1mm Cross-sectional area of ​​the honeycomb structure perpendicular to the direction in which the flow path extends: 6000 mm² 2 Length of the flow channel in the honeycomb structure in the direction of extension: 10 mm Volume resistivity of the materials constituting the outer walls and partitions at 25°C: 15 Ω·cm Curie point of materials constituting the outer walls and partition walls: 110°C

[0108] Next, the obtained honeycomb molded body was dielectric-dried and hot-air-dried, then degreased in a firing furnace under an atmospheric atmosphere (450°C for 4 hours), and subsequently fired under an atmospheric atmosphere to obtain a honeycomb structure. The firing was carried out by holding at 950°C for 1 hour, then raising the temperature to 1200°C and holding at 1200°C for 1 hour, and then raising the temperature to 1400°C (maximum temperature) at a heating rate of 200°C / hour and holding at 1400°C for 2 hours.

[0109] Next, a pair of electrodes were formed on both end faces (first and second end faces) of the obtained honeycomb structure. First, an electrode slurry containing aluminum (electrode material), ethyl cellulose, and diethylene glycol monobutyl ether (organic binder) was prepared, applied to the first end face, and then the electrode slurry was dried to form an electrode on the surface of the first end face. Similarly, using the same electrode slurry, an electrode was formed on the second end face by applying the electrode slurry and drying it. Next, using X-type zeolite (Example 1), Y-type zeolite (SiO2 / Al2O3 molar ratio 10) (Example 2), MFI-type zeolite (Example 3), Y-type zeolite (SiO2 / Al2O3 molar ratio 5) (Example 4), and A-type silica gel (Comparative Example 1) as adsorbents, a honeycomb structure with a pair of electrodes formed on it was immersed in a slurry containing the adsorbent, organic binder, and water. After removing the slurry adhering to excess locations (such as the outer periphery) by blowing and wiping, an adsorption layer with a thickness of 150 μm was formed on the surface of the partition wall and the outer periphery wall facing the cell by drying at a temperature of approximately 550°C.

[0110] The humidity control devices obtained as described above were placed inside the air conditioning duct to construct a humidity control system as shown in Figure 4. The following evaluation was performed on this humidity control system.

[0111] <Adsorption (moisture absorption) performance> After regeneration treatment was performed on the humidity control system, adsorption treatment was carried out. The regeneration treatment was performed by activating a ventilator and circulating air at a temperature of 25°C and relative humidity of 40% at a flow rate of 25 L / min through the air conditioning duct, while applying a voltage of 12V from a DC power supply to the humidity control device for 3 minutes. The adsorption treatment was performed by circulating air under the same conditions at a flow rate of 380 L / min through the air conditioning duct for 3 minutes without applying voltage to the humidity control device. In the dehumidification treatment, the absolute humidity [g / m³] at the inlet and outlet of the humidity control device was measured. 3 The amount of moisture absorbed [g] was calculated by measuring [ ] and using the following formula. Moisture absorption [g] = (Absolute humidity at the inlet of the humidity control device [g / m³]) 3 ]-Absolute humidity at the outlet of the humidity control device [g / m³]3 ])×Flow rate [m 3 [ / minute] × Adsorption processing time [minutes] Furthermore, a moisture absorption capacity of 3.0g or more indicates good adsorption performance.

[0112] <Regeneration (moisture release) performance> The humidity control system underwent an adsorption treatment followed by a regeneration treatment. The adsorption treatment was performed by activating a ventilator and circulating air at a temperature of 25°C and relative humidity of 40% through the air conditioning duct at a flow rate of 380 L / min for 3 minutes without applying voltage to the humidity control device. The regeneration treatment was performed by circulating air under the same conditions through the air conditioning duct at a flow rate of 25 L / min while applying a voltage of 12V from a DC power supply to the humidity control device for 3 minutes. In the regeneration treatment, the absolute humidity [g / m³] at the inlet and outlet of the humidity control device was measured. 3 The amount of moisture released [g] was calculated by measuring [ ] and using the following formula. Dehumidification rate [g] = (Absolute humidity at the outlet of the humidity control device [g / m³]) 3 ]-Absolute humidity at the inlet of the humidity control device [g / m³] 3 ])×Flow rate [m 3 [ / minute] × Playback processing time [minutes] Furthermore, a moisture release amount of 1.0g or more indicates good regeneration performance.

[0113] The evaluation results are shown in Table 1.

[0114] [Table 1]

[0115] As shown in Table 1, the humidity control devices of Examples 1 to 4 absorbed more moisture than the humidity control device of Comparative Example 1. This is thought to be because they were able to efficiently adsorb moisture not only in the upstream adsorption layer but also in the downstream adsorption layer, based on the direction of airflow. Furthermore, the humidity control devices of Examples 1 to 4 released more moisture than the humidity control device of Comparative Example 1, allowing for more efficient regeneration.

[0116] As can be seen from the above results, the present invention provides a humidity control device and humidity control system that can efficiently adsorb moisture from the air regardless of the humidity level in the air. [Explanation of Symbols]

[0117] 10 Humidity Control Devices 110 Base material part 111 Honeycomb structure 112 Outer wall 113 First end surface 114 Second end face 115 cells 116 Bulkhead 117,118 electrode 119 terminals 120 Adsorption part 121 Adsorption layer 20 Humidity Control System 210 Air conditioning duct 211 First channel 212 Second channel 220 Power supply 230 valves 240 Ventilator 250 Control Unit

Claims

1. Base material part, An adsorption portion provided on the surface of the substrate portion, containing an adsorbent capable of adsorbing and desorbing moisture, Equipped with, The adsorbent has a moisture adsorption amount Ad when the relative humidity is 20% or higher, as measured by the moisture adsorption isotherm. 20 When the amount is 15% by mass or more and the relative humidity is 8%, the amount of water adsorbed is Ad 8 Ad of moisture adsorption when relative humidity is 1% 1 The difference Ad 8 -Ad 1 A humidity control device in which the content is 5% by mass or more.

2. The adsorbent has a moisture adsorption amount Ad when the relative humidity is 20% or higher, as measured by the moisture adsorption isotherm. 20 The humidity control device according to claim 1, wherein the amount is 20% by mass or more.

3. The adsorbent has a moisture adsorption amount Ad when the relative humidity is 20% or higher, as measured by the moisture adsorption isotherm. 20 The humidity control device according to claim 1, wherein the amount is 23% by mass or more.

4. The adsorbent has a moisture adsorption amount Ad when the relative humidity is 20% or higher, as measured by the moisture adsorption isotherm. 20 The humidity control device according to claim 1, wherein the amount is 25% by mass or more.

5. In the water vapor adsorption isotherm, the adsorbent has a water adsorption amount Ad at a relative humidity of 8% 8 and a water adsorption amount Ad at a relative humidity of 1% 1 , the difference Ad 8 - Ad 1 is 8 mass% or more. The humidity conditioning device according to any one of claims 1 to 4.

6. The amount of water adsorbed by the adsorbent at a relative humidity of 8% is measured on the water adsorption isotherm. 8 Ad of moisture adsorption when relative humidity is 1% 1 The difference Ad 8 -Ad 1 A humidity control device according to any one of claims 1 to 4, wherein the amount is 10% by mass or more.

7. The amount of water adsorbed by the adsorbent at a relative humidity of 8% is measured on the water adsorption isotherm. 8 Ad of moisture adsorption when relative humidity is 1% 1 The difference Ad 8 -Ad 1 A humidity control device according to any one of claims 1 to 4, wherein the amount is 17% by mass or more.

8. The amount of water adsorbed by the adsorbent at a relative humidity of 5% is measured on the water adsorption isotherm. 5 Ad of moisture adsorption when relative humidity is 1% 1 The difference Ad 5 -Ad 1 A humidity control device according to any one of claims 1 to 4, wherein the amount is 5% by mass or more.

9. The amount of water adsorbed by the adsorbent at a relative humidity of 5% is measured on the water adsorption isotherm. 5 Ad of moisture adsorption when relative humidity is 3% 3 The difference Ad 5 -Ad 3 A humidity control device according to any one of claims 1 to 4, wherein the amount is 2% by mass or more.

10. The humidity control device according to any one of claims 1 to 4, wherein the adsorbent is one or more selected from X-type zeolite, Y-type zeolite, A-type zeolite, and MFI-type zeolite.

11. The adsorbent is SiO 2 / Al 2 O 3 A humidity control device according to any one of claims 1 to 4, wherein the molar ratio of the Y-type zeolite is 10 or less.

12. The base material is a honeycomb structure having an outer peripheral wall and partition walls disposed inside the outer peripheral wall that divide and form a plurality of cells that serve as air passages extending from a first end face to a second end face. The humidity control device according to any one of claims 1 to 4, wherein the adsorption portion is an adsorption layer provided on the surface of the partition wall.

13. The humidity control device according to claim 12, further comprising a pair of electrodes provided on the first and second end faces of the honeycomb structure, or on the outer peripheral wall parallel to the direction in which the cells of the honeycomb structure extend.

14. The humidity control device according to claim 12, wherein at least the partition wall of the honeycomb structure is made of a material having PTC properties.

15. A flow path through which air can circulate, A humidity control device according to any one of claims 1 to 4, disposed within the flow path, A humidity control system equipped with this feature.

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